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Sample records for optically thin plasma

  1. Atomic processes in optically thin plasmas

    Science.gov (United States)

    Kaastra, Jelle S.; Gu, Liyi; Mao, Junjie; Mehdipour, Missagh; Raassen, Ton; Urdampilleta, Igone

    2016-10-01

    The Universe contains a broad range of plasmas with quite different properties depending on distinct physical processes. In this contribution we give an overview of recent developments in modeling such plasmas with a focus on X-ray emission and absorption. Despite the fact that such plasmas have been investigated already for decades, and that overall there is a good understanding of the basic processes, there are still areas, where improvements have to be made that are important for the analysis of astrophysical plasmas. We present recent work on the update of atomic parameters in the codes that describe the emission from collisional plasmas, where older approximations are being replaced now by more accurate data. Further we discuss the development of models for photo-ionised plasmas in the context of outflows around supermassive black holes and models for charge transfer that are needed for analyzing the data from the upcoming ASTRO-H satellite.

  2. Spectral evolution of soft x-ray emission from optically thin, high electron temperature platinum plasmas

    Directory of Open Access Journals (Sweden)

    Hiroyuki Hara

    2017-08-01

    Full Text Available The soft x-ray spectra of heavy element plasmas are frequently dominated by unresolved transition array (UTA emission. We describe the spectral evolution of an intense UTA under optically thin conditions in platinum plasmas. The UTA was observed to have a peak wavelength around 4.6 nm at line-of-sight averaged electron temperatures less than 1.4 keV at electron densities of (2.5–7.5 × 1013 cm−3. The UTA spectral structure was due to emission from 4d–4f transitions in highly charged ions with average charge states of q = 20–40. A numerical simulation successfully reproduced the observed spectral behavior.

  3. Spectral evolution of soft x-ray emission from optically thin, high electron temperature platinum plasmas

    Science.gov (United States)

    Hara, Hiroyuki; Ohashi, Hayato; Li, Bowen; Dunne, Padraig; O'Sullivan, Gerry; Sasaki, Akira; Suzuki, Chihiro; Tamura, Naoki; Sakaue, Hiroyuki A.; Kato, Daiji; Murakami, Izumi; Higashiguchi, Takeshi; LHD Experiment Group

    2017-08-01

    The soft x-ray spectra of heavy element plasmas are frequently dominated by unresolved transition array (UTA) emission. We describe the spectral evolution of an intense UTA under optically thin conditions in platinum plasmas. The UTA was observed to have a peak wavelength around 4.6 nm at line-of-sight averaged electron temperatures less than 1.4 keV at electron densities of (2.5-7.5) × 1013 cm-3. The UTA spectral structure was due to emission from 4d-4f transitions in highly charged ions with average charge states of q = 20-40. A numerical simulation successfully reproduced the observed spectral behavior.

  4. On the optical and electrical properties of rf and a.c. plasma polymerized aniline thin films

    Indian Academy of Sciences (India)

    U S Sajeev; C Joseph Mathai; S Saravanan; Rajeev R Ashokan; S Venkatachalam; M R Anantharaman

    2006-04-01

    Polyaniline is a widely studied conducting polymer and is a useful material in its bulk and thin film form for many applications, because of its excellent optical and electrical properties. Pristine and iodine doped polyaniline thin films were prepared by a.c. and rf plasma polymerization techniques separately for the comparison of their optical and electrical properties. Doping of iodine was effected in situ. The structural properties of these films were evaluated by FTIR spectroscopy and the optical band gap was estimated from UV-vis-NIR measurements. Comparative studies on the structural, optical and electrical properties of a.c. and rf polymerization are presented here. It has been found that the optical band gap of the polyaniline thin films prepared by rf and a.c. plasma polymerization techniques differ considerably and the band gap is further reduced by in situ doping of iodine. The electrical conductivity measurements on these films show a higher value of electrical conductivity in the case of rf plasma polymerized thin films when compared to the a.c. plasma polymerized films. Also, it is found that the iodine doping enhanced conductivity of the polymer thin films considerably. The results are compared and correlated and have been explained with respect to the different structures adopted under these two preparation techniques.

  5. Magneto-Acoustic Waves of Small Amplitude in Optically Thin Quasi-Isentropic Plasmas

    CERN Document Server

    Nakariakov, V M; Ibáñez, M H; Nakariakov, Valery M.; Mendoza-Briceno, Cesar A.

    1999-01-01

    The evolution of quasi-isentropic magnetohydrodynamic waves of small but finite amplitude in an optically thin plasma is analyzed. The plasma is assumed to be initially homogeneous, in thermal equilibrium and with a straight and homogeneous magnetic field frozen in. Depending on the particular form of the heating/cooling function, the plasma may act as a dissipative or active medium for magnetoacoustic waves, while Alfven waves are not directly affected. An evolutionary equation for fast and slow magnetoacoustic waves in the single wave limit, has been derived and solved, allowing us to analyse the wave modification by competition of weakly nonlinear and quasi-isentropic effects. It was shown that the sign of the quasi-isentropic term determines the scenario of the evolution, either dissipative or active. In the dissipative case, when the plasma is first order isentropically stable the magnetoacoustic waves are damped and the time for shock wave formation is delayed. However, in the active case when the plasm...

  6. Optical spectroscopic analyses of CVD plasmas used in the deposition of transparent and conductive ZnO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Martin, A.; Espinos, J.P.; Yubero, F.; Barranco, A.; Gonzalez-Elipe, A.R. [Instituto de Ciencias de Materiales de Sevilla, CSIC-Universidad de Sevilla (Spain); Cotrino, J. [Universidad de Sevilla, Facultad de Fisica, Dept. de Fisica Atomica, Molecular y Nuclear, Sevilla (Spain)

    2001-07-01

    Transparent conducting ZnO:A1 thin films have been prepared by remote plasma enhanced chemical vapor deposition. Emission line profiles were recorded as a function of different plasma gas composition (oxygen and hydrogen mixtures) and different rates of precursors (Zn(C{sub 2}H{sub 5}){sub 2} and A1(CH{sub 3}){sub 3}) in the downstream zone of the plasma reactor. Optical emission spectroscopy were used to characterize the oxygen/hydrogen plasma as a function of hydrogen flow rate. The variation of plasma hydrogen content has an important influence in the resistivity of the films. (authors)

  7. Dynamics of double-pulse laser produced titanium plasma inferred from thin film morphology and optical emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Krstulović, N., E-mail: niksak@ifs.hr [Institute of Physics, Bijenička 46, HR-10000 Zagreb (Croatia); Salamon, K., E-mail: ksalamon@ifs.hr [Institute of Physics, Bijenička 46, HR-10000 Zagreb (Croatia); Modic, M., E-mail: martina.modic@ijs.si [Jožef Stefan Institute, Jamova 39, 1001 Ljubljana (Slovenia); Bišćan, M., E-mail: mbiscan@ifs.hr [Institute of Physics, Bijenička 46, HR-10000 Zagreb (Croatia); Milat, O., E-mail: milat@ifs.hr [Institute of Physics, Bijenička 46, HR-10000 Zagreb (Croatia); Milošević, S., E-mail: slobodan@ifs.hr [Institute of Physics, Bijenička 46, HR-10000 Zagreb (Croatia)

    2015-05-01

    In this paper, dynamics of double-pulse laser produced titanium plasma was studied both directly using optical emission spectroscopy (OES) and indirectly from morphological properties of deposited thin films. Both approaches yield consistent results. Ablated material was deposited in a form of thin film on the Si substrate. During deposition, plasma dynamics was monitored using optical emission spectroscopy with spatial and temporal resolutions. The influence of ablation mode (single and double) and delay time τ (delay between first and second pulses in double-pulse mode) on plasma dynamics and consequently on morphology of deposited Ti-films was studied using X-ray reflectivity and atomic force microscopy. Delay time τ was varied from 170 ns to 4 μs. The results show strong dependence of both emission signal and Ti-film properties, such as thickness, density and roughness, on τ. In addition, correlation of average density and thickness of film is observed. These results are discussed in terms of dependency of angular distribution and kinetic energy of plasma plume particles on τ. Advantages of using double-pulse laser deposition for possible application in thin film production are shown. - Highlights: • Ti-thin films produced by single and double pulse laser ablation mode. • Ablation mode and delay time influenced plasma plume and film characteristics. • Films are most compact for optimized delay time (thinnest, smoothest and most dense). • Plasma dynamics can be inferred from film characteristics.

  8. Influence of the radio-frequency power on the physical and optical properties of plasma polymerized cyclohexane thin films

    Energy Technology Data Exchange (ETDEWEB)

    Manaa, C., E-mail: chadlia.el.manaa@gmail.com [Laboratoire de Physique de la Matière Condensée, Université de Picardie Jules Verne, UFR des Sciences d' Amiens, 33 rue Saint Leu, 80039 Amiens CEDEX 2 (France); Laboratoire des Matériaux Avancés et Phénomènes Quantiques, Université de Tunis El-Manar, Faculté des Sciences de Tunis, Campus universitaire El-Manar, 1068 Tunis (Tunisia); Lejeune, M. [Laboratoire de Physique de la Matière Condensée, Université de Picardie Jules Verne, UFR des Sciences d' Amiens, 33 rue Saint Leu, 80039 Amiens CEDEX 2 (France); Kouki, F. [Laboratoire des Matériaux Avancés et Phénomènes Quantiques, Université de Tunis El-Manar, Faculté des Sciences de Tunis, Campus universitaire El-Manar, 1068 Tunis (Tunisia); Durand-Drouhin, O. [Laboratoire de Physique de la Matière Condensée, Université de Picardie Jules Verne, UFR des Sciences d' Amiens, 33 rue Saint Leu, 80039 Amiens CEDEX 2 (France); Bouchriha, H. [Laboratoire des Matériaux Avancés et Phénomènes Quantiques, Université de Tunis El-Manar, Faculté des Sciences de Tunis, Campus universitaire El-Manar, 1068 Tunis (Tunisia); and others

    2014-06-02

    We investigate in the present study the effects of the radio-frequency plasma power on the opto-electronical properties of the polymeric amorphous hydrogenated carbon thin films deposited at room temperature and different radio-frequency powers by plasma-enhanced chemical vapor deposition method using cyclohexane as precursor. A combination of U.V.–Visible and infrared transmission measurements is applied to characterize the bonding and electronic properties of these films. Some film properties namely surface roughness, contact angle, surface energy, and optical properties are found to be significantly influenced by the radio-frequency power. The changes in these properties are analyzed within the microstructural modifications occurring during growth. - Highlights: • Effects of the radio-frequency power on the optoelectronic properties of thin films • Elaboration of plasma polymerized thin films using cyclohexane as precursor gas • The use of U.V.–Visible-infrared transmission, and optical gap • Study of the surface topography of the films by using Atomic Force microscopy • The use of a capacitively coupled plasma enhanced chemical vapor deposition method.

  9. Ion irradiation as a tool for modifying the surface and optical properties of plasma polymerised thin films

    Science.gov (United States)

    Grant, Daniel S.; Bazaka, Kateryna; Siegele, Rainer; Holt, Stephen A.; Jacob, Mohan V.

    2015-10-01

    Radio frequency (R.F.) glow discharge polyterpenol thin films were prepared on silicon wafers and irradiated with I10+ ions to fluences of 1 × 1010 and 1 × 1012 ions/cm2. Post-irradiation characterisation of these films indicated the development of well-defined nano-scale ion entry tracks, highlighting prospective applications for ion irradiated polyterpenol thin films in a variety of membrane and nanotube-fabrication functions. Optical characterisation showed the films to be optically transparent within the visible spectrum and revealed an ability to selectively control the thin film refractive index as a function of fluence. This indicates that ion irradiation processing may be employed to produce plasma-polymer waveguides to accommodate a variety of wavelengths. XRR probing of the substrate-thin film interface revealed interfacial roughness values comparable to those obtained for the uncoated substrate's surface (i.e., both on the order of 5 Å), indicating minimal substrate etching during the plasma deposition process.

  10. Optical and electrical characteristics of plasma enhanced chemical vapor deposition boron carbonitride thin films derived from N-trimethylborazine precursor

    Energy Technology Data Exchange (ETDEWEB)

    Sulyaeva, Veronica S., E-mail: veronica@niic.nsc.ru [Department of Functional Materials Chemistry, Nikolaev Institute of Inorganic Chemistry SB RAS, Novosibirsk 630090 (Russian Federation); Kosinova, Marina L.; Rumyantsev, Yurii M.; Kuznetsov, Fedor A. [Department of Functional Materials Chemistry, Nikolaev Institute of Inorganic Chemistry SB RAS, Novosibirsk 630090 (Russian Federation); Kesler, Valerii G. [Laboratory of Physical Principles for Integrated Microelectronics, Rzhanov Institute of Semiconductor Physics SB RAS, Novosibirsk 630090 (Russian Federation); Kirienko, Viktor V. [Laboratory of Nonequilibrium Semiconductors Systems, Rzhanov Institute of Semiconductor Physics SB RAS, Novosibirsk 630090 (Russian Federation)

    2014-05-02

    Thin BC{sub x}N{sub y} films have been obtained by plasma enhanced chemical vapor deposition using N-trimethylborazine as a precursor. The films were deposited on Si(100) and fused silica substrates. The grown films were characterized by ellipsometry, Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray energy dispersive spectroscopy, X-ray photoelectron spectroscopy, spectrophotometry, capacitance–voltage and current–voltage measurements. The deposition parameters, such as substrate temperature (373–973 K) and gas phase composition were varied. Low temperature BC{sub x}N{sub y} films were found to be high optical transparent layers in the range of 300–2000 nm, the transmittance as high as 93% has been achieved. BC{sub x}N{sub y} layers are dielectrics with dielectric constant k = 2.2–8.9 depending on the synthesis conditions. - Highlights: • Thin BC{sub x}N{sub y} films have been obtained by plasma enhanced chemical vapor deposition. • N-trimethylborazine was used as a precursor. • Low temperature BC{sub x}N{sub y} films were found to be high optical transparent layers (93%). • BC{sub x}N{sub y} layers are dielectrics with dielectric constant k = 2.2–8.9.

  11. Formation of oxygen vacancies and Ti3+ state in TiO2 thin film and enhanced optical properties by air plasma treatment

    OpenAIRE

    Bandna Bharti; Santosh Kumar; Heung-No Lee; Rajesh Kumar

    2016-01-01

    This is the first time we report that simply air plasma treatment can also enhances the optical absorbance and absorption region of titanium oxide (TiO2) films, while keeping them transparent. TiO2 thin films having moderate doping of Fe and Co exhibit significant enhancement in the aforementioned optical properties upon air plasma treatment. The moderate doping could facilitate the formation of charge trap centers or avoid the formation of charge recombination centers. Variation in surface s...

  12. Optical and Surface Characterization of Radio Frequency Plasma Polymerized 1-Isopropyl-4-Methyl-1,4-Cyclohexadiene Thin Films

    Directory of Open Access Journals (Sweden)

    Jakaria Ahmad

    2014-04-01

    Full Text Available Low pressure radio frequency plasma-assisted deposition of 1-isopropyl-4-methyl-1,4-cyclohexadiene thin films was investigated for different polymerization conditions. Transparent, environmentally stable and flexible, these organic films are promising candidates for organic photovoltaics (OPV and flexible electronics applications, where they can be used as encapsulating coatings and insulating interlayers. The effect of deposition RF power on optical properties of the films was limited, with all films being optically transparent, with refractive indices in a range of 1.57–1.58 at 500 nm. The optical band gap (Eg of ~3 eV fell into the insulating Eg region, decreasing for films fabricated at higher RF power. Independent of deposition conditions, the surfaces were smooth and defect-free, with uniformly distributed morphological features and average roughness between 0.30 nm (at 10 W and 0.21 nm (at 75 W. Films fabricated at higher deposition power displayed enhanced resistance to delamination and wear, and improved hardness, from 0.40 GPa for 10 W to 0.58 GPa for 75 W at a load of 700 μN. From an application perspective, it is therefore possible to tune the mechanical and morphological properties of these films without compromising their optical transparency or insulating property.

  13. Ar plasma irradiation improved optical and electrical properties of TiO₂/Ag/TiO₂ multilayer thin film.

    Science.gov (United States)

    Fang, Yingcui; He, Jinjun; Zhang, Kang; Xiao, Chuanyun; Zhang, Bing; Shen, Jie; Niu, Haihong; Yan, Rong; Chen, Junling

    2015-12-01

    Embedding a thin metal layer between two thin dielectric or semiconductor layers [dielectric/metal/dielectric (DMD)] leads to a kind of transparent electrode that is promising as a substitute for the currently widely applied indium tin oxide electrode. However, the optical and electrical properties of DMD still wait for further improvement. In this study, Ar plasma irradiation (API) was, for the first time to our knowledge, applied to improve the optical and electrical properties of a TiO2/Ag/TiO2 electrode that was fabricated by electron-beam evaporation of TiO2 and electric-resistance heating of high purity Ag under vacuum. Ar plasma was produced by radio frequency glow discharge. The Ag layer was bombarded before the second layer of TiO2 was deposited. The electrode with configuration of TiO2 (24  nm)/Ag(14  nm)/TiO2 (24  nm) after API for 10 s shows excellent performance. The mean transmittance between 370 and 800 nm reaches 94% and the sheet resistance is as low as 6  Ω/sq, while Haacke's figure of merit is as high as 112×10(-3)  Ω(-1). The improvement mechanism is discussed based on field emission scanning electron microscope images and absorption spectra. The improvement is attributed to the fact that API reduces the localized surface plasmon resonance of Ag nanoparticles and makes the Ag film thinner and denser.

  14. Photocatalytic Anatase TiO2 Thin Films on Polymer Optical Fiber Using Atmospheric-Pressure Plasma.

    Science.gov (United States)

    Baba, Kamal; Bulou, Simon; Choquet, Patrick; Boscher, Nicolas D

    2017-04-06

    Due to the undeniable industrial advantages of low-temperature atmospheric-pressure plasma processes, such as low cost, low temperature, easy implementation, and in-line process capabilities, they have become the most promising next-generation candidate system for replacing thermal chemical vapor deposition or wet chemical processes for the deposition of functional coatings. In the work detailed in this article, photocatalytic anatase TiO2 thin films were deposited at a low temperature on polymer optical fibers using an atmospheric-pressure plasma process. This method overcomes the challenge of forming crystalline transition metal oxide coatings on polymer substrates by using a dry and up-scalable method. The careful selection of the plasma source and the titanium precursor, i.e., titanium ethoxide with a short alkoxy group, allowed the deposition of well-adherent, dense, and crystalline TiO2 coatings at low substrate temperature. Raman and XRD investigations showed that the addition of oxygen to the precursor's carrier gas resulted in a further increase of the film's crystallinity. Furthermore, the films deposited in the presence of oxygen exhibited a better photocatalytic activity toward methylene blue degradation assumedly due to their higher amount of photoactive {101} facets.

  15. Direct synthesis and characterization of optically transparent conformal zinc oxide nanocrystalline thin films by rapid thermal plasma CVD.

    Science.gov (United States)

    Pedersen, Joachim D; Esposito, Heather J; Teh, Kwok Siong

    2011-10-31

    We report a rapid, self-catalyzed, solid precursor-based thermal plasma chemical vapor deposition process for depositing a conformal, nonporous, and optically transparent nanocrystalline ZnO thin film at 130 Torr (0.17 atm). Pure solid zinc is inductively heated and melted, followed by ionization by thermal induction argon/oxygen plasma to produce conformal, nonporous nanocrystalline ZnO films at a growth rate of up to 50 nm/min on amorphous and crystalline substrates including Si (100), fused quartz, glass, muscovite, c- and a-plane sapphire (Al2O3), gold, titanium, and polyimide. X-ray diffraction indicates the grains of as-deposited ZnO to be highly textured, with the fastest growth occurring along the c-axis. The individual grains are observed to be faceted by (103) planes which are the slowest growth planes. ZnO nanocrystalline films of nominal thicknesses of 200 nm are deposited at substrate temperatures of 330°C and 160°C on metal/ceramic substrates and polymer substrates, respectively. In addition, 20-nm- and 200-nm-thick films are also deposited on quartz substrates for optical characterization. At optical spectra above 375 nm, the measured optical transmittance of a 200-nm-thick ZnO film is greater than 80%, while that of a 20-nm-thick film is close to 100%. For a 200-nm-thick ZnO film with an average grain size of 100 nm, a four-point probe measurement shows electrical conductivity of up to 910 S/m. Annealing of 200-nm-thick ZnO films in 300 sccm pure argon at temperatures ranging from 750°C to 950°C (at homologous temperatures between 0.46 and 0.54) alters the textures and morphologies of the thin film. Based on scanning electron microscope images, higher annealing temperatures appear to restructure the ZnO nanocrystalline films to form nanorods of ZnO due to a combination of grain boundary diffusion and bulk diffusion.PACS: films and coatings, 81.15.-z; nanocrystalline materials, 81.07.Bc; II-VI semiconductors, 81.05.Dz.

  16. Nonlinear optical thin films

    Science.gov (United States)

    Leslie, Thomas M.

    1993-01-01

    A focused approach to development and evaluation of organic polymer films for use in optoelectronics is presented. The issues and challenges that are addressed include: (1) material synthesis, purification, and the tailoring of the material properties; (2) deposition of uniform thin films by a variety of methods; (3) characterization of material physical properties (thermal, electrical, optical, and electro-optical); and (4) device fabrication and testing. Photonic materials, devices, and systems were identified as critical technology areas by the Department of Commerce and the Department of Defense. This approach offers strong integration of basic material issues through engineering applications by the development of materials that can be exploited as the active unit in a variety of polymeric thin film devices. Improved materials were developed with unprecedented purity and stability. The absorptive properties can be tailored and controlled to provide significant improvement in propagation losses and nonlinear performance. Furthermore, the materials were incorporated into polymers that are highly compatible with fabrication and patterning processes for integrated optical devices and circuits. By simultaneously addressing the issues of materials development and characterization, keeping device design and fabrication in mind, many obstacles were overcome for implementation of these polymeric materials and devices into systems. We intend to considerably improve the upper use temperature, poling stability, and compatibility with silicon based devices. The principal device application that was targeted is a linear electro-optic modulation etalon. Organic polymers need to be properly designed and coupled with existing integrated circuit technology to create new photonic devices for optical communication, image processing, other laser applications such as harmonic generation, and eventually optical computing. The progression from microscopic sample to a suitable film

  17. Formation of oxygen vacancies and Ti3+ state in TiO2 thin film and enhanced optical properties by air plasma treatment

    Science.gov (United States)

    Bharti, Bandna; Kumar, Santosh; Lee, Heung-No; Kumar, Rajesh

    2016-08-01

    This is the first time we report that simply air plasma treatment can also enhances the optical absorbance and absorption region of titanium oxide (TiO2) films, while keeping them transparent. TiO2 thin films having moderate doping of Fe and Co exhibit significant enhancement in the aforementioned optical properties upon air plasma treatment. The moderate doping could facilitate the formation of charge trap centers or avoid the formation of charge recombination centers. Variation in surface species viz. Ti3+, Ti4+, O2‑, oxygen vacancies, OH group and optical properties was studied using X-ray photon spectroscopy (XPS) and UV-Vis spectroscopy. The air plasma treatment caused enhanced optical absorbance and optical absorption region as revealed by the formation of Ti3+ and oxygen vacancies in the band gap of TiO2 films. The samples were treated in plasma with varying treatment time from 0 to 60 seconds. With the increasing treatment time, Ti3+ and oxygen vacancies increased in the Fe and Co doped TiO2 films leading to increased absorbance; however, the increase in optical absorption region/red shift (from 3.22 to 3.00 eV) was observed in Fe doped TiO2 films, on the contrary Co doped TiO2 films exhibited blue shift (from 3.36 to 3.62 eV) due to Burstein Moss shift.

  18. Structural and optical characterization of thick and thin polycrystalline diamond films deposited by microwave plasma activated CVD

    Indian Academy of Sciences (India)

    S K Pradhan; B Satpati; B P Bag; T Sharda

    2012-02-01

    Preliminary results of growth of thin diamond film in a recently installed 3 kW capacity microwave plasma activated CVD (MW-PACVD) system are being reported. The films were deposited on Si (100) substrate at 850°C using methane and hydrogen mixture at 1.5 kW MW power. The grown polycrystalline films were characterized by micro-Raman, transmission electron microscope (TEM), spectrophotometer and atomic force microscope (AFM). The results were compared with that of a thicker diamond film grown elsewhere in a same make MWPACVD system at relatively higher power densities. The presence of a sharp Raman peak at 1332 cm-1 confirmed the growth of diamond, and transmission spectra showed typical diamond film characteristics in both the samples. Typical twin bands and also a quintuplet twinned crystal were observed in TEM, further it was found that the twinned region in thin sample composed of very fine platelet like structure.

  19. Optical emission spectroscopy study of the expansion dynamics of a laser generated plasma during the deposition of thin films by laser ablation

    Directory of Open Access Journals (Sweden)

    Fazio, Enza

    2007-09-01

    Full Text Available The dynamics of the expanding plasma produced by excimer laser ablation of different materials such as silicon, silicon carbide, graphite and tin powder were studied by means of time integrated, spatially resolved emission spectroscopy and fast photography imaging of the expanding plasma. Experiments were performed both in vacuum and in different pure background atmosphere (i.e. oxygen or nitrogen and, finally, in gaseous mixtures (i.e. in O2/Ar and N2/Ar mixtures. These investigations were performed to gather information on the nature of the chemical species present in the plasma and on the occurrence of chemical reactions during the interaction between the plasma and the background gas. Then, we tried to correlate the plasma expansion dynamics to the structural and physical properties of the deposited materials. Experimental results clearly indicate that there is a strong correlation between the plasma expansion dynamics and the structural properties of the deposited thin films. In this respect, the investigations performed by means of fast photography and of optical emission spectroscopy revealed themselves as powerful tools for an efficient control of the deposition process itself.

  20. A procedure for estimating the electron temperature and the departure of the LTE condition in a time-dependent, spatially homogeneous, optically thin plasma

    Energy Technology Data Exchange (ETDEWEB)

    Bredice, F. [Centro de Investigaciones Opticas, La Plata (Argentina); Borges, F.O., E-mail: borges@if.uff.br [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Instituto de Fisica. Lab. de Plasma e Espectroscopia; Di Rocco, H.O. [Instituto de Fisica Arroyo Seco (IFAS), Universidad Nacional del Centro, Tandil (Argentina); Mercado, R.S. [Grupo de Espectroscopia Optica de Emision y Laser (GEOEL), Universidad del Atlantico, Barranquilla (Colombia); Villagran-Muniz, M. [Laboratorio de Fotofisica, Centro de Ciencias Aplicadas y Desarrollo Tecnologico, Universidad Nacional Autonoma de Mexico (Mexico); Palleschi, V. [Applied Laser Spectroscopy Laboratory, ICCOM-CNR, Pisa (Italy)

    2013-08-15

    We present a method to estimate the temperature of transient plasmas and their degree of departure from local thermodynamic equilibrium conditions. Our method is based on application of the Saha–Boltzmann equations on the temporal variation of the intensity of the spectral lines of the plasma, under the assumption that the plasmas at the different times when the spectra were obtained are in local thermodynamic equilibrium. The method requires no knowledge of the spectral efficiency of the spectrometer/detector, transition probabilities of the considered lines, or degeneracies of the upper and lower levels. Provided that the conditions of optically thin, homogeneous plasma in local thermodynamic equilibrium are satisfied, the accuracy of the procedure is limited only by the precision with which the line intensities and densities can be determined at two different temperatures. The procedure generates an equation describing the temporal evolution of the electron number density of transient plasmas under local thermodynamic equilibrium conditions. The method is applied to the analysis of two laser-induced breakdown spectra of cadmium at different temperatures. (author)

  1. Optical plasma microelectronic devices

    CERN Document Server

    Forati, Ebrahim; Dill, Thyler; Sievenpiper, Dan

    2015-01-01

    The semiconductor channel in conventional microelectronic devices was successfully replaced with an optically triggered gas plasma channel. The combination of DC and laser-induced gas ionizations controls the conductivity of the channel, enabling us to realize different electronic devices such as transistors, switches, modulators, etc. A special micro-scale metasurface was used to enhance the laser-gas interaction, as well as combining it with DC ionization properly. Optical plasma devices benefit form the advantages of plasma/vacuum electronic devices while preserving most of the integrablity of semiconductor based devices.

  2. Influence of plasma parameters and substrate temperature on the structural and optical properties of CdTe thin films deposited on glass by laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Quiñones-Galván, J. G.; Santana-Aranda, M. A.; Pérez-Centeno, A. [Departamento de Física, Centro Universitario de Ciencias Exactas e Ingenierías, Universidad de Guadalajara, Boulevard Marcelino García Barragán 1421, Guadalajara, Jalisco C.P. 44430 (Mexico); Camps, Enrique [Departamento de Física, Instituto Nacional de Investigaciones Nucleares, Apartado Postal 18-1027, D.F., C.P. 11801 (Mexico); Campos-González, E.; Guillén-Cervantes, A.; Santoyo-Salazar, J.; Zelaya-Angel, O. [Departamento de Física, CINVESTAV-IPN, Apartado Postal 14-740, D. F. C.P. 07360 (Mexico); Hernández-Hernández, A. [Escuela Superior de Apan, Universidad Autónoma del Estado de Hidalgo, Calle Ejido de Chimalpa Tlalayote s/n Colonia Chimalpa, Apan Hidalgo (Mexico); Moure-Flores, F. de [Facultad de Química, Materiales, Universidad Autónoma de Querétaro, Querétaro C.P. 76010 (Mexico)

    2015-09-28

    In the pulsed laser deposition of thin films, plasma parameters such as energy and density of ions play an important role in the properties of materials. In the present work, cadmium telluride thin films were obtained by laser ablation of a stoichiometric CdTe target in vacuum, using two different values for: substrate temperature (RT and 200 °C) and plasma energy (120 and 200 eV). Structural characterization revealed that the crystalline phase can be changed by controlling both plasma energy and substrate temperature; which affects the corresponding band gap energy. All the thin films showed smooth surfaces and a Te rich composition.

  3. Effects of phosphorus doping by plasma immersion ion implantation on the structural and optical characteristics of Zn0.85Mg0.15O thin films

    Science.gov (United States)

    Saha, S.; Nagar, S.; Chakrabarti, S.

    2014-08-01

    ZnMgO thin films deposited on Si substrates by RF sputtering were annealed at 800, 900, and 1000 °C after phosphorus plasma immersion ion implantation. X-ray diffraction spectra confirmed the presence of and peaks for all the samples. However, in case of the annealed samples, the peak was also observed. Scanning electron microscopy images revealed the variation in surface morphology caused by phosphorus implantation. Implanted and non-implanted samples were compared to examine the effects of phosphorus implantation on the optical properties of ZnMgO. Optical characteristics were investigated by low-temperature (15 K) photoluminescence experiments. Inelastic exciton-exciton scattering and localized, and delocalized excitonic peaks appeared at 3.377, 3.42, and 3.45 eV, respectively, revealing the excitonic effect resulting from phosphorus implantation. This result is important because inelastic exciton-exciton scattering leads to nonlinear emission, which can improve the performance of many optoelectronic devices.

  4. Effect of ion bombardment on the structural and optical properties of TiO{sub 2} thin films deposited from oxygen/titanium tetraisopropoxide inductively coupled plasma

    Energy Technology Data Exchange (ETDEWEB)

    Li, D. [College of Mechanical Engineering, Yangzhou University, Yangzhou 225127 (China); Carette, M.; Granier, A.; Landesman, J.P. [Institut des Matériaux Jean Rouxel (IMN), Université de Nantes, UMR CNRS 6502, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3 (France); Goullet, A., E-mail: antoine.goullet@univ-nantes.fr [Institut des Matériaux Jean Rouxel (IMN), Université de Nantes, UMR CNRS 6502, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3 (France)

    2015-08-31

    Titanium dioxide films were deposited on silicon substrates from oxygen/titanium tetraisopropoxide inductively coupled radiofrequency plasmas in a helicon reactor operated at low temperature (< 150 °C) and low pressure (0.4 Pa). The effect of the ion energy (E{sub i}), varied in the 15–175 eV range, on the morphology, microstructure and optical properties of the films is investigated. Scanning electron microscopy (SEM) shows that at low energy (E{sub i} = 15 eV), the film exhibits a columnar morphology consisting of a bottom dense layer, an intermediate gradient layer and a top roughness layer. Increasing the ion energy results in more homogeneous films along the growth direction as confirmed by the in-situ kinetic ellipsometry measurements and post deposition spectroscopic ellipsometry data analysis. In addition, the atomic force microscopy (AFM) measurements reveal that the film top surface becomes smoother as E{sub i} is increased. X-ray diffraction (XRD) diagrams show that only anatase is identified in the film deposited at 15 eV, whereas the complete phase transformation from anatase to rutile occurs at E{sub i} = 75 eV. These results are in good agreement with the Fourier transform infrared spectroscopy (FTIR) spectra which also show that the hydroxyl groups absorbed in the films deposited at 15 eV, are greatly decreased for E{sub i} ≥ 45 eV. Suitable structural models combined with the Tauc–Lorentz dispersion law have been found to accurately fit the spectroscopic ellipsometry experimental data. The results in good agreement with SEM and AFM measurements are also consistent with the structural properties evidenced by XRD and FTIR. The refractive index (n) can be increased significantly by increasing the ion energy from 15 eV to 75 eV, reaching a value of 2.49 at 1.96 eV. Upon increasing the ion energy above 75 eV n is shown to decrease due to micropores which are formed in the films. - Highlights: • TiO{sub 2} thin films deposited in inductively

  5. Collisional Ionization Equilibrium for Optically Thin Plasmas. I. Updated Recombination Rate Coefficients for Bare though Sodium-like Ions

    CERN Document Server

    Bryans, P; Gorczyca, T W; Laming, J M; Mitthumsiri, W; Savin, D W

    2006-01-01

    Reliably interpreting spectra from electron-ionized cosmic plasmas requires accurate ionization balance calculations for the plasma in question. However, much of the atomic data needed for these calculations have not been generated using modern theoretical methods and are often highly suspect. This translates directly into the reliability of the collisional ionization equilibrium (CIE) calculations. We make use of state-of-the-art calculations of dielectronic recombination (DR) rate coefficients for the hydrogenic through Na-like ions of all elements from He up to and including Zn. We also make use of state-of-the-art radiative recombination (RR) rate coefficient calculations for the bare through Na-like ions of all elements from H through to Zn. Here we present improved CIE calculations for temperatures from $10^4$ to $10^9$ K using our data and the recommended electron impact ionization data of \\citet{Mazz98a} for elements up to and including Ni and Mazzotta (private communication) for Cu and Zn. DR and RR ...

  6. Optical properties of cluster plasma

    Energy Technology Data Exchange (ETDEWEB)

    Kishimoto, Yasuaki; Tajima, Toshiki [Japan Atomic Energy Research Inst., Neyagawa, Osaka (Japan). Kansai Research Establishment; Downer, M.C.

    1998-03-01

    It is shown that unlike a gas plasma or an electron plasma in a metal, an ionized clustered material (`cluster plasma`) permits propagation below the plasma cut-off of electromagnetic (EM) waves whose phase velocity is close to but below the speed of light. This results from the excitation of a plasma oscillation mode (and/or polarization mode) through the cluster surface which does not exist in usual gaseous plasma. The existence of this new optical mode, cluster mode, is confirmed via numerical simulation. (author)

  7. Properties of silicon nitride thin overlays deposited on optical fibers — Effect of fiber suspension in radio frequency plasma-enhanced chemical vapor deposition reactor

    Energy Technology Data Exchange (ETDEWEB)

    Śmietana, M., E-mail: M.Smietana@elka.pw.edu.pl [Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, Warsaw 00-662 (Poland); Dominik, M.; Myśliwiec, M.; Kwietniewski, N. [Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, Warsaw 00-662 (Poland); Mikulic, P. [Centre de Recherche en Photonique, Université du Québec en Outaouais, 101 rue Saint-Jean-Bosco, Gatineau, J8X 3X7, Québec (Canada); Witkowski, B.S. [Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, Warsaw 02-666 (Poland); Bock, W.J. [Centre de Recherche en Photonique, Université du Québec en Outaouais, 101 rue Saint-Jean-Bosco, Gatineau, J8X 3X7, Québec (Canada)

    2016-03-31

    This work discusses the effect of sample suspension in radio frequency plasma-enhanced chemical vapor deposition process on properties of the obtained overlays. Silicon nitride (SiN{sub x}) overlays were deposited on flat silicon wafers and cylindrical fused silica optical fibers. The influence of the suspension height and fiber diameter on SiN{sub x} deposition rate is investigated. It has been found that thickness of the SiN{sub x} overlay significantly increases with suspension height, and the deposition rate depends on fiber dimensions. Moreover, the SiN{sub x} overlays were also deposited on long-period gratings (LPGs) induced in optical fiber. Measurements of the LPG spectral response combined with its numerical simulations allowed for a discussion on properties of the deposited overlay. The measurements have proven higher overlay deposition rate on the suspended fiber than on flat Si wafer placed on the electrode. Results of this work are essential for precise tuning of the functional properties of new generations of optical devices such as optical sensors, filters and resonators, which typically are based on optical fibers and require the overlays with well defined properties. - Highlights: • The effect of optical fiber suspension in plasma process is discussed. • The deposition rate of silicon nitride (SiN{sub x}) overlay depends on fiber dimensions. • Thickness of the SiN{sub x} overlay strongly increases with suspension height. • Measurements and simulations of long-period grating confirms experimental results.

  8. Optical characteristics of nanocrystalline Al{sub x}Ga{sub 1−x}N thin films deposited by hollow cathode plasma-assisted atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Goldenberg, Eda, E-mail: goldenberg@unam.bilkent.edu.tr [UNAM – National Nanotechnology Research Center, Bilkent University, Ankara 06800 (Turkey); Ozgit-Akgun, Cagla; Biyikli, Necmi [Institute of Materials Science and Nanotechnology, Bilkent University, Ankara 06800 (Turkey); Kemal Okyay, Ali [Department of Electrical and Electronics Engineering, Bilkent University, Ankara 06800 (Turkey)

    2014-05-15

    Gallium nitride (GaN), aluminum nitride (AlN), and Al{sub x}Ga{sub 1−x}N films have been deposited by hollow cathode plasma-assisted atomic layer deposition at 200 °C on c-plane sapphire and Si substrates. The dependence of film structure, absorption edge, and refractive index on postdeposition annealing were examined by x-ray diffraction, spectrophotometry, and spectroscopic ellipsometry measurements, respectively. Well-adhered, uniform, and polycrystalline wurtzite (hexagonal) GaN, AlN, and Al{sub x}Ga{sub 1−x}N films were prepared at low deposition temperature. As revealed by the x-ray diffraction analyses, crystallite sizes of the films were between 11.7 and 25.2 nm. The crystallite size of as-deposited GaN film increased from 11.7 to 12.1 and 14.4 nm when the annealing duration increased from 30 min to 2 h (800 °C). For all films, the average optical transmission was ∼85% in the visible (VIS) and near infrared spectrum. The refractive indices of AlN and Al{sub x}Ga{sub 1−x}N were lower compared to GaN thin films. The refractive index of as-deposited films decreased from 2.33 to 2.02 (λ = 550 nm) with the increased Al content x (0 ≤ x ≤ 1), while the extinction coefficients (k) were approximately zero in the VIS spectrum (>400 nm). Postdeposition annealing at 900 °C for 2 h considerably lowered the refractive index value of GaN films (2.33–1.92), indicating a significant phase change. The optical bandgap of as-deposited GaN film was found to be 3.95 eV, and it decreased to 3.90 eV for films annealed at 800 °C for 30 min and 2 h. On the other hand, this value increased to 4.1 eV for GaN films annealed at 900 °C for 2 h. This might be caused by Ga{sub 2}O{sub 3} formation and following phase change. The optical bandgap value of as-deposited Al{sub x}Ga{sub 1−x}N films decreased from 5.75 to 5.25 eV when the x values decreased from 1 to 0.68. Furthermore, postdeposition annealing did not

  9. Near-field optical thin microcavity theory

    Science.gov (United States)

    Wu, Jiu Hui; Hou, Jiejie

    2016-01-01

    The thin microcavity theory for near-field optics is proposed in this study. By applying the power flow theorem and the variable theorem,the bi-harmonic differential governing equation for electromagnetic field of a three-dimensional thin microcavity is derived for the first time. Then by using the Hankel transform, this governing equation is solved exactly and all the electromagnetic components inside and outside the microcavity can be obtained accurately. According to the above theory, the near-field optical diffraction from a subwavelength aperture embedded in a thin conducting film is investigated, and numerical computations are performed to illustrate the edge effect by an enhancement factor of 1.8 and the depolarization phenomenon of the near-field transmission in terms of the distance from the film surface. This thin microcavity theory is verified by the good agreement between our results and those in the previous literatures. The thin microcavity theory presented in the study should be useful in the possible applications of the thin microcavities in near-field optics and thin-film optics.

  10. Modifications in SnS thin films by plasma treatments

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, H., E-mail: hm@fis.unam.mx [Instituto de Ciencias Fisicas, Universidad Nacional Autonoma de Mexico, Apartado Postal 48-3, 62210 Cuernavaca, Morelos (Mexico); Avellaneda, D. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon (Mexico)

    2012-02-01

    The present study shows the modifications of structural, optical and electrical characteristics that occur in tin sulfide (SnS) thin films treated in air and in nitrogen plasma at different pressure conditions. The films were obtained by the chemical bath deposition method, which results in SnS thin films with an orthorhombic crystalline structure, band gap (E{sub g}) of 1.1-1.2 eV, and electrical conductivities ({sigma}) in the order of 10{sup -6} {Omega}{sup -1}cm{sup -1}. The films treated with air plasma at pressures between 1 and 4 Torr, showed the presence of SnS{sub 2}, Sn{sub 2}S{sub 3}, and SnO{sub 2} phases, within the band gap values ranging from 0.9 to 1.5 eV. On the other hand, the films treated with nitrogen plasma presented the same phases, but showed a significant modification in the electrical conductivity, increasing from 10{sup -6} {Omega}{sup -1}cm{sup -1} (as-deposited) up to 10{sup -2}-10{sup -3} {Omega}{sup -1}cm{sup -1} (plasma treated). This result is a suitable range of conductivity for the improvement of the solar cells with SnS as an absorber material. Also, emission spectroscopy measurements were carried out in both air and nitrogen plasma treatments.

  11. Impact of low-pressure glow-discharge-pulsed plasma polymerization on properties of polyaniline thin films

    Science.gov (United States)

    Jatratkar, Aviraj A.; Yadav, Jyotiprakash B.; Deshmukh, R. R.; Barshilia, Harish C.; Puri, Vijaya; Puri, R. K.

    2016-12-01

    This study reports on polyaniline thin films deposited on a glass substrate using a low-pressure glow-discharge-pulsed plasma polymerization method. The polyaniline thin film obtained by pulsed plasma polymerization has been successfully demonstrated as an optical waveguide with a transmission loss of 3.93 dB cm-1, and has the potential to be employed in integrated optics. An attempt has been made to investigate the effect of plasma OFF-time on the structural, optical as well as surface properties of polyaniline thin film. The plasma ON-time has been kept constant and the plasma OFF-time has been varied throughout the work. The plasma OFF-time strongly influenced the properties of the polyaniline thin film, and a nanostructured and compact surface was revealed in the morphological studies. The plasma OFF-time was found to enhance film thickness, roughness, refractive index and optical transmission loss, whereas it reduced the optical band gap of the polyaniline thin films. Retention in the aromatic structure was confirmed by FTIR results. Optical studies revealed a π-π* electronic transition at about 317 nm as well as the formation of a branched structure. As compared with continuous wave plasma, pulsed plasma polymerization shows better properties. Pulsed plasma polymerization reduced the roughness of the film from 1.2 nm to 0.42 nm and the optical transmission loss from 6.56 dB cm-1 to 3.39 dB cm-1.

  12. Optical thin films user handbook

    CERN Document Server

    Rancourt, James D

    1996-01-01

    Practical, user-oriented reference for engineers who must incorporate and specify coatings for filters, antiglare effects, polarization, or other purposes in optical or electro-optical systems design. It focuses on preparation techniques and characteristics of commercially available products and provides information needed to determine what type of filter is needed to solve a particular problem, what its limitations are, and how to care for it.

  13. Optical thin films and coatings from materials to applications

    CERN Document Server

    Flory, Francois

    2013-01-01

    Optical coatings, including mirrors, anti-reflection coatings, beam splitters, and filters, are an integral part of most modern optical systems. This book provides an overview of thin film materials, the properties, design and manufacture of optical coatings and their use across a variety of application areas.$bOptical coatings, including mirrors, anti-reflection coatings, beam splitters, and filters, are an integral part of most modern optical systems. Optical thin films and coatings provides an overview of thin film materials, the properties, design and manufacture of optical coatings and their use across a variety of application areas. Part one explores the design and manufacture of optical coatings. Part two highlights unconventional features of optical thin films including scattering properties of random structures in thin films, optical properties of thin film materials at short wavelengths, thermal properties and colour effects. Part three focusses on novel materials for optical thin films and coatings...

  14. Modification of optical and electrical properties of chemical bath deposited CdS using plasma treatments

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, G. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon, C.P 66450 (Mexico); Krishnan, B. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon, C.P 66450 (Mexico); CIIDIT, Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico); Avellaneda, D.; Castillo, G. Alan; Das Roy, T.K. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon, C.P 66450 (Mexico); Shaji, S., E-mail: sshajis@yahoo.com [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon, C.P 66450 (Mexico); CIIDIT, Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico)

    2011-08-31

    Cadmium sulphide (CdS) is a well known n-type semiconductor that is widely used in solar cells. Here we report preparation and characterization of chemical bath deposited CdS thin films and modification of their optical and electrical properties using plasma treatments. CdS thin films were prepared from a chemical bath containing Cadmium chloride, Triethanolamine and Thiourea under various deposition conditions. Good quality thin films were obtained during deposition times of 5, 10 and 15 min. CdS thin films prepared for 10 min. were treated using a glow discharge plasma having nitrogen and argon carrier gases. The changes in morphology, optical and electrical properties of these plasma treated CdS thin films were analyzed in detail. The results obtained show that plasma treatment is an effective technique in modification of the optical and electrical properties of chemical bath deposited CdS thin films.

  15. Optical Constants of Cadmium Telluride Thin Film

    Science.gov (United States)

    Nithyakalyani, P.; Pandiaraman, M.; Pannir, P.; Sanjeeviraja, C.; Soundararajan, N.

    2008-04-01

    Cadmium Telluride (CdTe) is II-VI direct band gap semiconductor compound with potential application in Solar Energy conversion process. CdTe thin film of thickness 220 mn was prepared by thermal evaporation technique at a high vacuum better than 10-5 m.bar on well cleaned glass substrates of dimensions (l cm×3 cm). The transmittance spectrum and the reflectance spectrum of the prepared CdTc thin film was recorded using UV-Vis Spectrophotometer in the wavelength range between 300 nm and 900 nm. These spectral data were analyzed and the optical band and optical constants of CdTe Thin film have been determined by adopting suitable relations. The optical band gap of CdTe thin film is found to be 1.56 eV and this value is also agreeing with the published works of CdTe thin film prepared by various techniques. The absorption coefficient (α) has been higher than 106 cm-1. The Refractive index (n) and the Extinction Coefficient (k) are found to be varying from 3.0 to 4.0 and 0.1 Cm-1 to 0.5 Cm-1 respectively by varying the energy from l.0 eV to 4.0 eV. These results are also compared with the literature.

  16. Microwave plasma: its characteristics and applications in thin film technology

    Energy Technology Data Exchange (ETDEWEB)

    Musil, J.

    Microwave plasmas differ significantly from other plasmas, exhibit many interesting properties and so offer new possibilities for the plasma processing of thin films. Plasma properties strongly depend on the conditions and methods used to excite the gas. Due to the existence of a direct connection between the properties of plasma-prepared thin films and plasma micro-parameters a perfect knowledge of the plasma generation is a basic requirement for mastering a plasma deposition process. Therefore, different methods of generating microwave isotropic and anisotropic plasmas are discussed. Special attention is devoted to the mechanisms of plasma excitation and to the generation of a dense and homogeneous plasma in thin film technology are also presented.

  17. ZnO and Al doped ZnO thin films deposited by Spray Plasma: Effect of the growth time and Al doping on microstructural, optical and electrical properties

    Energy Technology Data Exchange (ETDEWEB)

    Baba, Kamal [LSPM-CNRS, Laboratoire des Sciences des Procédés et des Matériaux (UPR 3407), Université Paris 13 Sorbonne Paris Cité, 93430 Villetaneuse (France); Luxembourg Institute of Science and Technology, Materials Research and Technology Department, L-4362 Esch-sur-Alzette (Luxembourg); Lazzaroni, Claudia [LSPM-CNRS, Laboratoire des Sciences des Procédés et des Matériaux (UPR 3407), Université Paris 13 Sorbonne Paris Cité, 93430 Villetaneuse (France); Nikravech, Mehrdad, E-mail: mehrdad.nikravech@lspm.cnrs.fr [LSPM-CNRS, Laboratoire des Sciences des Procédés et des Matériaux (UPR 3407), Université Paris 13 Sorbonne Paris Cité, 93430 Villetaneuse (France)

    2015-11-30

    Nanostructured zinc oxide (ZnO) and Al doped ZnO (ZnO:Al) thin films are deposited on glass substrate by the Spray Plasma technique. Zinc nitrate and aluminium nitrate are used as Zn and Al precursors, respectively. The effect of the growth time on structural and optical properties of undoped films is studied by X-ray diffraction, atomic force microscopy, and UV–Vis spectroscopy. The effect of Al doping on microstructural, optical and electrical characteristics of ZnO:Al films is also investigated. The results show that the grain size and the film thickness both increase with the growth time. The band gap of the layers varies from 3.17 to 3.24 eV depending on the thickness. The increase of the Al doping results in the enlargement of the peak (002) and the shift of its position to higher 2θ values. Average optical transmittance decreases from 90 to 65% with the growth time because of the thickness increase while there is no significant influence of the aluminium doping on the transmittance which is above 80% in most of the visible and near-IR range for all ZnO:Al films. The electrical properties characterized by Hall measurements show that all the deposited films exhibit high resistivity, between 4 and 10{sup 4} Ω cm. The carrier concentration decreases from 2.10{sup 19} to 2.10{sup 13} cm{sup −3} when the concentration of Al increases from 1.5 to 5 atm%. - Highlights: • The original Spray Plasma technique is used for ZnO and ZnO:Al thin film deposition. • Investigation of the effect of growth time and Al doping on the structural and optical properties • Increase of grain size and film thickness with the growth time • Optical transmittance decreases from 90 to 65% with the growth time and is above 80% for ZnO:Al films in UV–Vis-NIR range. • The peak position of the (002) plane is shifted to high 2θ values with Al doping.

  18. Atomically thin nonreciprocal optical isolation

    Science.gov (United States)

    Lin, Xiao; Wang, Zuojia; Gao, Fei; Zhang, Baile; Chen, Hongsheng

    2014-01-01

    Optical isolators will play a critical role in next-generation photonic circuits, but their on-chip integration requires miniaturization with suitable nonreciprocal photonic materials. Here, we theoretically demonstrate the thinnest possible and polarization-selective nonreciprocal isolation for circularly polarized waves by using graphene monolayer under an external magnetic field. The underlying mechanism is that graphene electron velocity can be largely different for the incident wave propagating in opposite directions at cyclotron frequency, making graphene highly conductive and reflective in one propagation direction while transparent in the opposite propagation direction under an external magnetic field. When some practical loss is introduced, nonreciprocal isolation with graphene monolayer still possesses good performance in a broad bandwidth. Our work shows the first study on the extreme limit of thickness for optical isolation and provides theoretical guidance in future practical applications. PMID:24569672

  19. Optical diagnostics of dusty plasmas during nanoparticle growth

    Science.gov (United States)

    Mikikian, M.; Labidi, S.; von Wahl, E.; Lagrange, J. F.; Lecas, T.; Massereau-Guilbaud, V.; Géraud-Grenier, I.; Kovacevic, E.; Berndt, J.; Kersten, H.; Gibert, T.

    2017-01-01

    Carbon-based thin films deposited on surfaces exposed to a typical capacitively-coupled RF plasma are sources of molecular precursors at the origin of nanoparticle growth. This growth leads to drastic changes of the plasma characteristics. Thus, a precise understanding of the dusty plasma structure and dynamics is required to control the plasma evolution and the nanoparticle growth. Optical diagnostics can reveal some particular features occurring in these kinds of plasmas. High-speed imaging of the plasma glow shows that instabilities induced by nanoparticle growth can be constituted of small brighter plasma regions (plasmoids) that rotate around the electrodes. A single bigger region of enhanced emission is also of particular interest: the void, a main central dust-free region, has very distinct plasma properties than the surrounding dusty region. This particularity is emphasized using optical emission spectroscopy with spatiotemporal resolution. Emission profiles are obtained for the buffer gas and the carbonaceous molecules giving insights on the changes of the electron energy distribution function during dust particle growth. Dense clouds of nanoparticles are shown to be easily formed from two different thin films, one constituted of polymer and the other one created by the plasma decomposition of ethanol.

  20. Practical design and production of optical thin films

    CERN Document Server

    Willey, Ronald R

    2002-01-01

    Fundamentals of Thin Film Optics and the Use of Graphical Methods in Thin Film Design Estimating What Can Be Done Before Designing Fourier Viewpoint of Optical Coatings Typical Equipment for Optical Coating Production Materials and Process Know-How Process Development Monitoring and Control of Thin Film Growth Appendix: Metallic and Semiconductor Material Graphs Author IndexSubject Index

  1. Design of Gradient Index Optical Thin Films

    Science.gov (United States)

    1996-06-12

    Editors, Proc. SPIE, 2046:179-188 (1993). 2 Arfken , G. Mathematical Methods for Physicists (Third Edition). Orlando: Academic Press, 1985. 3 Berning, P. H...plasma," in Inhomogeneous and Quasi- Inhomogeneous Optical Coatings, J. A. Dobrowolski, P. G. Verly, Editors, Proc. SPIE, 2046:179-188 (1993). 2 Arfken ...Inhomogeneous Optical Coatings, J. A. Dobrowolski, P. G. Verly, Editors, Proc. SPIE, 2046:179-188 (1993). 2 Arfken , G. Mathematical Methods for Physicists

  2. Optical plasma torch electron bunch generation in plasma wakefield accelerators

    Directory of Open Access Journals (Sweden)

    G. Wittig

    2015-08-01

    Full Text Available A novel, flexible method of witness electron bunch generation in plasma wakefield accelerators is described. A quasistationary plasma region is ignited by a focused laser pulse prior to the arrival of the plasma wave. This localized, shapeable optical plasma torch causes a strong distortion of the plasma blowout during passage of the electron driver bunch, leading to collective alteration of plasma electron trajectories and to controlled injection. This optically steered injection is more flexible and faster when compared to hydrodynamically controlled gas density transition injection methods.

  3. Thin-film optical shutter. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Matlow, S.L.

    1981-02-01

    A specific embodiment of macroconjugated macromolecules, the poly (p-phenylene)'s, has been chosen as the one most likely to meet all of the requirements of the Thin Film Optical Shutter project (TFOS). The reason for this choice is included. In order to be able to make meaningful calculations of the thermodynamic and optical properties of the poly (p-phenylene)'s a new quantum mechanical method was developed - Equilibrium Bond Length (EBL) Theory. Some results of EBL Theory are included.

  4. Effects of phosphorus doping by plasma immersion ion implantation on the structural and optical characteristics of Zn{sub 0.85}Mg{sub 0.15}O thin films

    Energy Technology Data Exchange (ETDEWEB)

    Saha, S.; Nagar, S.; Chakrabarti, S., E-mail: subho@ee.iitb.ac.in [Department of Electrical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076 (India)

    2014-08-11

    ZnMgO thin films deposited on 〈100〉 Si substrates by RF sputtering were annealed at 800, 900, and 1000 °C after phosphorus plasma immersion ion implantation. X-ray diffraction spectra confirmed the presence of 〈101{sup ¯}0〉 and 〈101{sup ¯}3〉 peaks for all the samples. However, in case of the annealed samples, the 〈0002〉 peak was also observed. Scanning electron microscopy images revealed the variation in surface morphology caused by phosphorus implantation. Implanted and non-implanted samples were compared to examine the effects of phosphorus implantation on the optical properties of ZnMgO. Optical characteristics were investigated by low-temperature (15 K) photoluminescence experiments. Inelastic exciton–exciton scattering and localized, and delocalized excitonic peaks appeared at 3.377, 3.42, and 3.45 eV, respectively, revealing the excitonic effect resulting from phosphorus implantation. This result is important because inelastic exciton–exciton scattering leads to nonlinear emission, which can improve the performance of many optoelectronic devices.

  5. Optical and Nonlinear Optical Response of Light Sensor Thin Films

    Directory of Open Access Journals (Sweden)

    S. Z. Weisz

    2005-04-01

    Full Text Available For potential ultrafast optical sensor application, both VO2 thin films andnanocomposite crystal-Si enriched SiO2 thin films grown on fused quartz substrates weresuccessfully prepared using pulsed laser deposition (PLD and RF co-sputteringtechniques. In photoluminescence (PL measurement c-Si/SiO2 film containsnanoparticles of crystal Si exhibits strong red emission with the band maximum rangingfrom 580 to 750 nm. With ultrashort pulsed laser excitation all films show extremelyintense and ultrafast nonlinear optical (NLO response. The recorded holography fromall these thin films in a degenerate-four-wave-mixing configuration shows extremelylarge third-order response. For VO2 thin films, an optically induced semiconductor-tometalphase transition (PT immediately occurred upon laser excitation. it accompanied.It turns out that the fast excited state dynamics was responsible to the induced PT. For c-Si/SiO2 film, its NLO response comes from the contribution of charge carriers created bylaser excitation in conduction band of the c-Si nanoparticles. It was verified byintroducing Eu3+ which is often used as a probe sensing the environment variations. Itturns out that the entire excited state dynamical process associated with the creation,movement and trapping of the charge carriers has a characteristic 500 ps duration.

  6. Optical diagnostics of femtosecond laser plasmas

    Institute of Scientific and Technical Information of China (English)

    李玉同; 张杰; 陈黎明; 夏江帆; 腾浩; 赵理曾; 林景全; 李英骏; 魏志义; 王龙; 江文勉

    2001-01-01

    Optical diagnostics of evolution of plasmas produced by ultrashort laser pulses is carried out using a femtosecond probing beam. The time sequence of plasma shadowgrams and interferograms are obtained. The filamentation instability in high_density region induces the local density modification. Large_scale toroidal magnetic fields confine plasma expansion in the transverse direction, resulting in the formation of a plasma jet. The plasma expansion along the target normal direction is found to scale as 1 2.

  7. Improving electrical properties of sol-gel derived zinc oxide thin films by plasma treatment

    Science.gov (United States)

    Talukder, Al-Ahsan; Pokharel, Jyotshna; Shrestha, Maheshwar; Fan, Qi H.

    2016-10-01

    Being a direct and wide bandgap semiconductor, zinc oxide is a suitable material for various optoelectronic applications. These applications require tuning and controlling over the electrical and optical properties of zinc oxide films. In this work, zinc oxide thin films were prepared by a solution method that led to oriented crystal growth along (002) plane. The zinc oxide thin films were treated with oxygen, hydrogen, and nitrogen plasmas. The films were characterized to reveal the effects of plasma treatments on transmittance, crystallinity, carrier density, carrier mobility, and electrical resistivity. Oxygen plasma treatment improved the crystallinity of the zinc oxide thin film without affecting the film's transmittance. Hydrogen plasma treatments were found very effective in improving the electrical conductivity sacrificing the film's transmittance. Nitrogen plasma treatment led to improved electrical conductivity without compromising the crystallinity and optical transmittance. Sequential oxygen, hydrogen, and nitrogen plasma treatments significantly reduced the resistivity of zinc oxide thin films by over two orders and maintained the transmittance close to the as-deposited films of ˜80% in visible wavelength range. This is the first work on the improvement of conductivity of solution-based zinc oxide films using the plasma treatment.

  8. An Electrochemical Experiment Using an Optically Transparent Thin Layer Electrode

    Science.gov (United States)

    DeAngelis, Thomas P.; Heineman, William R.

    1976-01-01

    Describes a unified experiment in which an optically transparent thin layer electrode is used to illustrate the techniques of thin layer electrochemistry, cyclic voltammetry, controlled potential coulometry, and spectroelectrochemistry. (MLH)

  9. Robust, Thin Optical Films for Extreme Environments

    Science.gov (United States)

    2006-01-01

    The environment of space presents scientists and engineers with the challenges of a harsh, unforgiving laboratory in which to conduct their scientific research. Solar astronomy and X-ray astronomy are two of the more challenging areas into which NASA scientists delve, as the optics for this high-tech work must be extremely sensitive and accurate, yet also be able to withstand the battering dished out by radiation, extreme temperature swings, and flying debris. Recent NASA work on this rugged equipment has led to the development of a strong, thin film for both space and laboratory use.

  10. Radiation from optically thin accretion discs

    Energy Technology Data Exchange (ETDEWEB)

    Tylenda, R. (Polska Akademia Nauk, Torun. Pracownia Astrofizyki)

    1981-01-01

    Accretion discs in cataclysmic variables with low rates of mass transfer, M < or approx. 10/sup 16/g s/sup -1/, have outer regions optically thin in continuum. A simple approach that allows one to calculate the radiation spectra from such discs is presented. A great number of disc models has been obtained in order to study the influence of various parameters (accretion rate, outer radius of the disc, inclination angle, mass of the accreting degenerate dwarf, viscosity parameter) of discs on the outgoing continuous spectra, emission lines and the UBV colours.

  11. Nonlinear optics of astaxanthin thin films

    Science.gov (United States)

    Esser, A.; Fisch, Herbert; Haas, Karl-Heinz; Haedicke, E.; Paust, J.; Schrof, Wolfgang; Ticktin, Anton

    1993-02-01

    Carotinoids exhibit large nonlinear optical properties due to their extended (pi) -electron system. Compared to other polyenes which show a broad distribution of conjugation lengths, carotinoids exhibit a well defined molecular structure, i.e. a well defined conjugation length. Therefore the carotinoid molecules can serve as model compounds to study the relationship between structure and nonlinear optical properties. In this paper the synthesis of four astaxanthins with C-numbers ranging from 30 to 60, their preparation into thin films, wavelength dispersive Third Harmonic Generation (THG) measurements and some molecular modelling calculations will be presented. Resonant (chi) (3) values reach 1.2(DOT)10-10 esu for C60 astaxanthin. In the nonresonant regime a figure of merit (chi) (3)/(alpha) of several 10-13 esu-cm is demonstrated.

  12. Plasma optical modulators for intense lasers

    CERN Document Server

    Yu, Lu-Le; Qian, Lie-Jia; Chen, Min; Weng, Su-Ming; Sheng, Zheng-Ming; Jaroszynski, D A; Mori, W B; Zhang, Jie

    2016-01-01

    Optical modulators can be made nowadays with high modulation speed, broad bandwidth, while being compact, owing to the recent advance in material science and microfabrication technology. However, these optical modulators usually work for low intensity light beams. Here, we present an ultrafast, plasma-based optical modulator, which can directly modulate high power lasers with intensity up to 10^16 W/cm^2 level to produce an extremely broad spectrum with a fractional bandwidth over 100%, extending to the mid-infrared regime in the low-frequency side. This concept relies on two co-propagating laser beams in a sub-mm-scale underdense plasma, where a drive laser pulse first excites an electron plasma wave in its wake while a following carrier laser beam is modulated by the plasma wave. The laser and plasma parameters suitable for the modulator to work are presented. Such optical modulators may enable new applications in the high field physics.

  13. Modelling of new generation plasma optical devices

    Directory of Open Access Journals (Sweden)

    Litovko Irina V.

    2016-06-01

    Full Text Available The paper presents new generation plasma optical devices based on the electrostatic plasma lens configuration that opens a novel attractive possibility for effective high-tech practical applications. Original approaches to use of plasma accelerators with closed electron drift and open walls for the creation of a cost-effective low-maintenance plasma lens with positive space charge and possible application for low-cost, low-energy rocket engine are described. The preliminary experimental, theoretical and simulation results are presented. It is noted that the presented plasma devices are attractive for many different applications in the state-of-the-art vacuum-plasma processing.

  14. Influence of hydrogen dilution on structural, electrical and optical properties of hydrogenated nanocrystalline silicon (nc-Si:H) thin films prepared by plasma enhanced chemical vapour deposition (PE-CVD)

    Energy Technology Data Exchange (ETDEWEB)

    Funde, A.M.; Bakr, Nabeel Ali; Kamble, D.K. [School of Energy Studies, University of Pune, Pune 411 007 (India); Hawaldar, R.R.; Amalnerkar, D.P. [Center for Materials for Electronics Technology (C-MET), Panchawati, Pune 411 008 (India); Jadkar, S.R. [Department of Physics, University of Pune, Ganeshkhind Road, Pune 411 007 (India)

    2008-10-15

    Hydrogenated nanocrystalline silicon (nc-Si:H) thin films were deposited from pure silane (SiH{sub 4}) and hydrogen (H{sub 2}) gas mixture by conventional plasma enhanced chemical vapour deposition (PE-CVD) method at low temperature (200 C) using high rf power. The structural, optical and electrical properties of these films are carefully and systematically investigated as a function of hydrogen dilution of silane (R). Characterization of these films with low angle X-ray diffraction and Raman spectroscopy revealed that the crystallite size in the films tends to decrease and at same time the volume fraction of crystallites increases with increase in R. The Fourier transform infrared (FTIR) spectroscopic analysis showed at low values of R, the hydrogen is predominantly incorporated in the nc-Si:H films in the mono-hydrogen (Si-H) bonding configuration. However, with increasing R the hydrogen bonding in nc-Si:H films shifts from mono-hydrogen (Si-H) to di-hydrogen (Si-H{sub 2}) and (Si-H{sub 2}){sub n} complexes. The hydrogen content in the nc-Si:H films decreases with increase in R and was found less than 10 at% over the entire studied range of R. On the other hand, the Tauc's optical band gap remains as high as 2 eV or much higher. The quantum size effect may responsible for higher band gap in nc-Si:H films. A correlation between electrical and structural properties has been found. For optimized deposition conditions, nc-Si:H films with crystallite size {proportional_to}7.67 nm having good degree of crystallinity ({proportional_to}84%) and high band gap (2.25 eV) were obtained with a low hydrogen content (6.5 at%). However, for these optimized conditions, the deposition rate was quite small (1.6 Aa/s). (author)

  15. Plasma synthesis of photocatalytic TiO x thin films

    Science.gov (United States)

    Sirghi, L.

    2016-06-01

    The development of efficient photocatalytic materials is promising technology for sustainable and green energy production, fabrication of self-cleaning, bactericidal, and super hydrophilic surfaces, CO2 photoreduction, and decomposition of toxic pollutants in air and water. Semiconductors with good photocatalytic activity have been known for four decades and they are regarded as promising candidates for these new technologies. Low-pressure discharge plasma is one of the most versatile technologies being used for the deposition of photocatalytic semiconductor thin films. This article reviews the main results obtained by the author in using low-pressure plasma for synthesis of TiO x thin films with applications in photocatalysis. Titanium dioxide thin films were obtained by radio frequency magnetron sputtering deposition, plasma enhanced chemical vapour deposition, and high power impulse magnetron sputtering deposition. The effects of the plasma deposition method, plasma parameters, film thickness and substrate on the film structure, chemical composition and photocatalytic activity are investigated. The photocatalytic activity of plasma synthesised TiO x thin films was estimated by UV light induced hydrophilicity. Measurements of photocurrent decay in TiO x thin films in vacuum and air showed that the photocatalytic activity is closely connected to the production, recombination and availability for surface reactions of photo-generated charge carriers. The photocatalytic activity of TiO x thin films was investigated at nanoscale by atomic force microscopy. Microscopic regions of different hydrophilicity on UV light irradiated films are discriminated by AFM atomic force microscopy measurements of adhesion and friction force.

  16. Development of plasma assisted thermal vapor deposition technique for high-quality thin film

    Science.gov (United States)

    Lee, Kang-Il; Choi, Yong Sup; Park, Hyun Jae

    2016-12-01

    The novel technique of Plasma-Assisted Vapor Deposition (PAVD) is developed as a new deposition method for thin metal films. The PAVD technique yields a high-quality thin film without any heating of the substrate because evaporated particles acquire energy from plasma that is confined to the inside of the evaporation source. Experiments of silver thin film deposition have been carried out in conditions of pressure lower than 10-3 Pa. Pure silver plasma generation is verified by the measurement of the Ag-I peak using optical emission spectroscopy. A four point probe and a UV-VIS spectrophotometer are used to measure the electrical and optical properties of the silver film that is deposited by PAVD. For an ultra-thin silver film with a thickness of 6.5 nm, we obtain the result of high-performance silver film properties, including a sheet resistance 75%. The PAVD-film properties show a low sheet resistance of 30% and the same transmittance with conventional thermal evaporation film. In the PAVD source, highly energetic particles and UV from plasma do not reach the substrate because the plasma is completely shielded by the optimized nozzle of the crucible. This new PAVD technique could be a realistic solution to improve the qualities of transparent electrodes for organic light emission device fabrication without causing damage to the organic layers.

  17. Optical modeling and simulation of thin-film photovoltaic devices

    CERN Document Server

    Krc, Janez

    2013-01-01

    In wafer-based and thin-film photovoltaic (PV) devices, the management of light is a crucial aspect of optimization since trapping sunlight in active parts of PV devices is essential for efficient energy conversions. Optical modeling and simulation enable efficient analysis and optimization of the optical situation in optoelectronic and PV devices. Optical Modeling and Simulation of Thin-Film Photovoltaic Devices provides readers with a thorough guide to performing optical modeling and simulations of thin-film solar cells and PV modules. It offers insight on examples of existing optical models

  18. Structure and Magneto-Optical Characteristic Study of Optical Multilayer Thin Films

    Institute of Scientific and Technical Information of China (English)

    YANG Cheng-tao

    2005-01-01

    @@ Based on the design theory of soft X-ray optical multilayer thin films and magneto-optic multilayer thin films, the metal multilayer thin films for the reflection of soft X-ray and ultraviolet ray, as well as the magneto-optic multilayer thin films for the magneto-optical memories were constructed. The metal multilayer thin films and the magneto-optic multilayer thin films were deposited with magnetron sputtering. The detail of optical reflection characteristics, layered-structure, and surface and interface characteristics were studied. At the same time,the static magneto-optical characteristics and dynamic magneto-optical characteristics of the magneto-optical disk were investigated.

  19. Plasma optical modulators for intense lasers

    Science.gov (United States)

    Yu, Lu-Le; Zhao, Yao; Qian, Lie-Jia; Chen, Min; Weng, Su-Ming; Sheng, Zheng-Ming; Jaroszynski, D. A.; Mori, W. B.; Zhang, Jie

    2016-06-01

    Optical modulators can have high modulation speed and broad bandwidth, while being compact. However, these optical modulators usually work for low-intensity light beams. Here we present an ultrafast, plasma-based optical modulator, which can directly modulate high-power lasers with intensity up to 1016 W cm-2 to produce an extremely broad spectrum with a fractional bandwidth over 100%, extending to the mid-infrared regime in the low-frequency side. This concept relies on two co-propagating laser pulses in a sub-millimetre-scale underdense plasma, where a drive laser pulse first excites an electron plasma wave in its wake while a following carrier laser pulse is modulated by the plasma wave. The laser and plasma parameters suitable for the modulator to work are based on numerical simulations.

  20. Optical Properties of Relativistic Plasma Mirrors

    CERN Document Server

    Vincenti, H; Kahaly, S; Martin, Ph; Quéré, F

    2013-01-01

    The advent of ultrahigh-power femtosecond lasers creates a need for optical components suitable to handle ultrahigh light intensities. Due to the unavoidable laser-induced ionization of matter, these components will have to be based on a plasma medium. An archetype of such optical elements is a plasma mirror, created when an intense femtosecond laser pulse impinges on a solid target. It consists of a dense plasma, formed by the laser field itself, which specularly reflects the main part of the pulse. Plasma mirrors have major potential applications as active optical elements to manipulate the temporal and spatial properties of intense laser beams, in particular for the generation of intense attosecond pulses of light. We investigate the basic physics involved in the deformation of a plasma mirror resulting from the light pressure exerted by the ultraintense laser during reflection, by deriving a simple model of this fundamental process, which we validate both numerically and experimentally. The understanding ...

  1. Optical properties of thin polymer films

    Science.gov (United States)

    Kasarova, Stefka N.; Sultanova, Nina G.; Petrova, Tzveta; Dragostinova, Violeta; Nikolov, Ivan

    2009-10-01

    In this report three types of optical polymer thin films deposited on glass substrates are investigated. Transmission spectra of the polymer samples are obtained in the range from 400 nm to 1500 nm. A laser microrefractometer has been used to measure the refractive indices of the examined materials at 406, 656, 910 and 1320 nm. Dispersion properties of the polymer films are analyzed on the base of the Cauchy-Schott's and Sellmeier`s approximations. Dispersion coefficients are calculated and dispersion charts in the visible and near infrared spectral regions are presented and compared. Abbe numbers of mean and partial dispersion of the polymer films are obtained. Calculation of refractive indices at many laser emission wavelengths in the considered spectral range is accomplished.

  2. An optical tweezer for complex plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Schablinski, Jan; Wieben, Frank; Block, Dietmar [Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Leibnizstrasse 17-19, 24098 Kiel (Germany)

    2015-04-15

    This paper describes the experimental realization of an optical trap for microparticles levitating in the plasma sheath. Single particles can be trapped in a laser beam comparable to optical tweezers known from colloidal suspensions. The trapping mechanism is discussed and two applications of the system are shown.

  3. Varying stress of SiOsub>xsub>Csub>ysub> thin films deposited by plasma polymerization.

    Science.gov (United States)

    Liao, Wei-Bo; Chang, Ya-Chen; Jaing, Cheng-Chung; Cheng, Ching-Long; Lee, Cheng-Chung; Wei, Hung-Sen; Kuo, Chien-Cheng

    2017-02-01

    SiOsub>xsub>Csub>ysub> thin films were deposited by plasma polymerization. The stress of the deposited SiOsub>xsub>Csub>ysub> thin films can be modified by adjusting the beam current, the anode voltage, and the flow rate of hexamethyldisiloxane (HMDSO) gas and oxygen. Reducing the beam current or increasing the flow rate of HMDSO gas increased the linear/cage structure ratio and turned the stress of the SiOsub>xsub>Csub>ysub> thin films from compressive to tensile. The linear/cage structure ratio can be adjusted by changing the composite parameter, W[FM]sub>csub>/[FM]sub>msub>, to control the stress of the deposited plasma polymer films. Multilayers of TiOsub>2sub>/SiOsub>2sub>/TiOsub>2sub> were coated on a SiOsub>xsub>Csub>ysub> plasma polymer film herein, reducing their stress by 70% from 0.06 to 0.018 GPa. The refractive index is 1.55, and the absorption coefficient is less than 10-4 at 550 nm of the SiOsub>xsub>Csub>ysub> films. Superior optical performances of SiOsub>xsub>Csub>ysub> thin films make their use in optical thin films.

  4. Recent development of plasma optical systems (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Goncharov, A. A., E-mail: gonchar@iop.kiev.ua [Institute of Physics, National Academy of Science, Kiev 03028 (Ukraine)

    2016-02-15

    The article devotes a brief description of the recent development and current status of an ongoing research of plasma optical systems based on the fundamental plasma optical idea magnetic electron isolation, equipotentialization magnetic field lines, and the axi-symmetric cylindrical electrostatic plasma lens (PL) configuration. The experimental, theoretical, and simulation investigations have been carried out over recent years collaboratively between IP NASU (Kiev), LBNL (Berkeley, USA), and HCEI RAS (Tomsk). The crossed electric and magnetic fields inherent the PL configuration that provides the attractive method for establishing a stable plasma discharge at low pressure. Using PL configuration, several high reliability plasma devices were developed. These devices are attractive for many high-tech applications.

  5. Nanoparticle formation and thin film deposition in aniline containing plasmas

    Science.gov (United States)

    Pattyn, Cedric; Dias, Ana; Hussain, Shahzad; Strunskus, Thomas; Stefanovic, Ilija; Boulmer-Leborgne, Chantal; Lecas, Thomas; Kovacevic, Eva; Berndt, Johannes

    2016-09-01

    This contribution deals with plasma based polymerization processes in mixtures of argon and aniline. The investigations are performed in a capacitively coupled RF discharge (in pulsed and continuous mode) and concern both the observed formation of nanoparticles in the plasma volume and the deposition of films. The latter process was used for the deposition of ultra-thin layers on different kind of nanocarbon materials (nanotubes and free standing graphene). The analysis of the plasma and the plasma chemistry (by means of mass spectroscopy and in-situ FTIR spectroscopy) is accompanied by several ex-situ diagnostics of the obtained materials which include NEXAFS and XPS measurements as well as Raman spectroscopy and electron microscopy. The decisive point of the investigations concern the preservation of the original monomer structure during the plasma polymerization processes and the stability of the thin films on the different substrates.

  6. UV optical properties of thin film oxide layers deposited by different processes.

    Science.gov (United States)

    Pellicori, Samuel F; Martinez, Carol L

    2011-10-01

    UV optical properties of thin film layers of compound and mixed oxide materials deposited by different processes are presented. Japan Electron Optics Laboratory plasma ion assisted deposition (JEOL PIAD), electron beam with and without IAD, and pulsed DC magnetron sputtering were used. Comparisons are made with published deposition process data. Refractive indices and absorption values to as short as 145 nm were measured by spectroscopic ellipsometry (SE). Electronic interband defect states are detected that are deposition-process dependent. SE might be effective in identifying UV optical film quality, especially in defining processes and material composition beneficial for high-energy excimer laser applications and environments requiring stable optical properties.

  7. Argon plasma inductively coupled plasma reactive ion etching study for smooth sidewall thin film lithium niobate waveguide application

    Science.gov (United States)

    Ulliac, G.; Calero, V.; Ndao, A.; Baida, F. I.; Bernal, M.-P.

    2016-03-01

    Lithium Niobate (LN) exhibits unique physical properties such as remarkable electro-optical coefficients and it is thus an excellent material for a wide range of fields like optic communications, lasers, nonlinear optical applications, electric field optical sensors etc. In order to further enhance the optical device performance and to be competitive with silicon photonics, sub-micrometric thickness lithium niobate films are crucial. A big step has been achieved with the development of LN thin films by using smart cut technology and wafer bonding and these films are nowadays available in the market. However, it is a challenge to obtain the requirements of the high quality thin LN film waveguide. In this letter, we show smooth ridge waveguides fabricated on 700 nm thickness thin film lithium niobate (TFLN). The fabrication has been done by developing and optimizing three steps of the technological process, the mask fabrication, the plasma etching, and a final cleaning wet etching step in order to remove the lithium niobate redeposition on the side walls. We have obtained single mode propagation with light overall losses of only 5 dB/cm.

  8. Nonlinear optical microscopy for imaging thin films and surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Smilowitz, L.B.; McBranch, D.W.; Robinson, J.M.

    1995-03-01

    We have used the inherent surface sensitivity of second harmonic generation to develop an instrument for nonlinear optical microscopy of surfaces and interfaces. We have demonstrated the use of several nonlinear optical responses for imaging thin films. The second harmonic response of a thin film of C{sub 60} has been used to image patterned films. Two photon absorption light induced fluorescence has been used to image patterned thin films of Rhodamine 6G. Applications of nonlinear optical microscopy include the imaging of charge injection and photoinduced charge transfer between layers in semiconductor heterojunction devices as well as across membranes in biological systems.

  9. Optical and electrical properties of chemical bath deposited cobalt sulphide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Govindasamy, Geetha [R& D Centre, Bharathiar University, Coimbatore (India); Murugasen, Priya, E-mail: priyamurugasen15@gmail.com [Department of Physics, Saveetha Engineering, Chennai, Tamil Nadu (India); Sagadevan, Suresh [Department of Physics, AMET University, Chennai, Tamil Nadu (India)

    2017-01-15

    Cobalt sulphide (CoS) thin films were synthesized using the Chemical Bath Deposition (CBD) technique. X-ray diffraction (XRD) analysis was used to study the structure and the crystallite size of CoS thin film. Scanning Electron Microscope (SEM) studies reveal the surface morphology of these films. The optical properties of the CoS thin films were determined using UV-Visible absorption spectrum. The optical band gap of the thin films was found to be 1.6 eV. Optical constants such as the refractive index, the extinction coefficient and the electric susceptibility were determined. The dielectric studies were carried out at different frequencies and at different temperatures for the prepared CoS thin films. In addition, the plasma energy of the valence electron, Penn gap or average energy gap, the Fermi energy and electronic polarizability of the thin films were determined. The AC electrical conductivity measurement was also carried out for the thin films. The activation energy was determined by using DC electrical conductivity measurement. (author)

  10. Ultra-thin plasma radiation detector

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, Peter S.

    2017-01-24

    A position-sensitive ionizing-radiation counting detector includes a radiation detector gas chamber having at least one ultra-thin chamber window and an ultra-thin first substrate contained within the gas chamber. The detector further includes a second substrate generally parallel to and coupled to the first substrate and defining a gas gap between the first substrate and the second substrate. The detector further includes a discharge gas between the substrates and contained within the gas chamber, where the discharge gas is free to circulate within the gas chamber and between the first and second substrates at a given gas pressure. The detector further includes a first electrode coupled to one of the substrates and a second electrode electrically coupled to the first electrode. The detector further includes a first discharge event detector coupled to at least one of the electrodes for detecting a gas discharge counting event in the electrode.

  11. Modeling plasmonic scattering combined with thin-film optics.

    Science.gov (United States)

    Schmid, M; Klenk, R; Lux-Steiner, M Ch; Topic, M; Krc, J

    2011-01-14

    Plasmonic scattering from metal nanostructures presents a promising concept for improving the conversion efficiency of solar cells. The determination of optimal nanostructures and their position within the solar cell is crucial to boost the efficiency. Therefore we established a one-dimensional optical model combining plasmonic scattering and thin-film optics to simulate optical properties of thin-film solar cells including metal nanoparticles. Scattering models based on dipole oscillations and Mie theory are presented and their integration in thin-film semi-coherent optical descriptions is explained. A plasmonic layer is introduced in the thin-film structure to simulate scattering properties as well as parasitic absorption in the metal nanoparticles. A proof of modeling concept is given for the case of metal-island grown silver nanoparticles on glass and ZnO:Al/glass substrates. Using simulations a promising application of the nanoparticle integration is shown for the case of CuGaSe(2) solar cells.

  12. Light waves in thin films and integrated optics.

    Science.gov (United States)

    Tien, P K

    1971-11-01

    Integrated optics is a far-reaching attempt to apply thin-film technology to optical circuits and devices, and, by using methods of integrated circuitry, to achieve a better and more economical optical system. The specific topics discussed here are physics of light waves in thin films, materials and losses involved, methods of couplings light beam into and out of a thin film, and nonlinear interactions in waveguide structures. The purpose of this paper is to review in some detail the important development of this new and fascinating field, and to caution the reader that the technology involved is difficult because of the smallness and perfection demanded by thin-film optical devices.

  13. Study of Linear and Non-Linear Optical Parameters of Zinc Selenide Thin Film

    Directory of Open Access Journals (Sweden)

    H. N. Desai

    2015-06-01

    Full Text Available Thin film of Zinc Selenide (ZnSe was deposited onto transparent glass substrate by thermal evaporation technique. ZnSe thin film was characterized by UV-Visible spectrophotometer within the wavelength range of 310 nm-1080 nm. The Linear optical parameters (linear optical absorption, extinction coefficient, refractive index and complex dielectric constant of ZnSe thin film were analyzed from absorption spectra. The optical band gap and Urbach energy were obtained by Tauc’s equation. The volume and surface energy loss function of ZnSe thin film were obtained by complex dielectric constant. The Dispersion parameters (dispersion energy, oscillation energy, moment of optical dispersion spectra, static dielectric constant and static refractive index were calculated using theoretical Wemple-DiDomenico model. The oscillation strength, oscillator wavelength, high frequency dielectric constant and high frequency refractive index were calculated by single Sellmeier oscillator model. Also, Lattice dielectric constant, N/m* and plasma resonance frequency were obtained. The electronic polarizibility of ZnSe thin film was estimated by Clausius-Mossotti local field polarizibility. The nonlinear optical parameters (non-linear susceptibility and non-linear refractive index were estimated.

  14. Plasma monitoring and PECVD process control in thin film silicon-based solar cell manufacturing

    Directory of Open Access Journals (Sweden)

    Gabriel Onno

    2014-02-01

    Full Text Available A key process in thin film silicon-based solar cell manufacturing is plasma enhanced chemical vapor deposition (PECVD of the active layers. The deposition process can be monitored in situ by plasma diagnostics. Three types of complementary diagnostics, namely optical emission spectroscopy, mass spectrometry and non-linear extended electron dynamics are applied to an industrial-type PECVD reactor. We investigated the influence of substrate and chamber wall temperature and chamber history on the PECVD process. The impact of chamber wall conditioning on the solar cell performance is demonstrated.

  15. Optical properties of aluminum oxide thin films and colloidal nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Koushki, E., E-mail: ehsan.koushki@yahoo.com [Photonics Laboratory, Physics Faculty, Kharazmi University, Tehran (Iran, Islamic Republic of); Physics Department, Hakim Sabzevari University, Sabzevar (Iran, Islamic Republic of); Mousavi, S.H. [INM—Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken (Germany); Jafari Mohammadi, S.A. [INM—Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken (Germany); Department of Chemistry, College of Science, Islamshahr Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Majles Ara, M.H. [Photonics Laboratory, Physics Faculty, Kharazmi University, Tehran (Iran, Islamic Republic of); Oliveira, P.W. de [INM—Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken (Germany)

    2015-10-01

    In this work, we prepared thin films of aluminum oxide (Al{sub 2}O{sub 3}) with different thicknesses, using a wet chemical process. The Al{sub 2}O{sub 3} nanoparticles with an average size of 40 nm were dispersed in water and deposited on soda glass substrates. The morphology of the resulting thin films was characterized by means of scanning electron microscopy. The optical properties of the thin films were studied by measuring reflectance and transmittance. A theoretical description of the reflection and transmission mechanism of the films was developed by measuring the thickness and spectral behavior of the refractive index. Numerical evaluations were used for modeling the optical spectra of the thin films of alumina. By fitting numerical curves to the experimental data, the extinction coefficient and refractive index were obtained. The dielectric constant and optical properties of the colloidal solution of the particles were also studied. - Highlights: • Optical properties of alumina thin films and nanocolloids were investigated. • New theoretical depiction of transmission and reflection from the thin films was evaluated. • Interference in reflection from thin films was studied. • Real and imaginary parts of the dielectric constant for alumina nanoparticles were calculated. • Using a novel method, evaluation of optical dispersion and UV–visible absorption were performed.

  16. Optical properties of polysiloxane hybrid thin films containing nano-sized Ag-As-Se chalcogenide clusters

    Science.gov (United States)

    Zha, Congji; Osvath, Peter; Wilson, Gerry; Launikonis, Anton

    2009-02-01

    Chalcogenide glasses are attractive for all-optical signal processing due to their outstanding optical properties, including large optical nonlinearity, a high refractive index and high photosensitivity. In device fabrication, a challenge lies in the difficulty of obtaining thin films with a high stability and good uniformity. In this paper, optical thin films containing nano-sized chalcogenide clusters in polysiloxane matrices are fabricated by a modified plasma deposition process. The optical absorption and luminescence emission properties of the hybrid thin films were characterized by UV-Vis-NIR and fluorescence spectroscopy. Luminescent emission from Ag-As-Se nano-sized clusters was observed for the first time in these nano-hybrid thin films, and the mechanism was discussed.

  17. Thin Film Solar Cells and their Optical Properties

    Directory of Open Access Journals (Sweden)

    Stanislav Jurecka

    2006-01-01

    Full Text Available In this work we report on the optical parameters of the semiconductor thin film for solar cell applications determination. The method is based on the dynamical modeling of the spectral reflectance function combined with the stochastic optimization of the initial reflectance model estimation. The spectral dependency of the thin film optical parameters computations is based on the optical transitions modeling. The combination of the dynamical modeling and the stochastic optimization of the initial theoretical model estimation enable comfortable analysis of the spectral dependencies of the optical parameters and incorporation of the microstructure effects on the solar cell properties. The results of the optical parameters ofthe i-a-Si thin film determination are presented.

  18. Optics and Plasma Research Department annual progress report for 2004

    DEFF Research Database (Denmark)

    Bindslev, Henrik; Lynov, Jens-Peter; Pedersen, C.

    2005-01-01

    , optical materials, biophotonics, fusion plasma physics, and industrial plasma technology. The department employs key technologies in micro- and nanotechnology for optical systems, temperaturecalibration, and infrared measurement techniques. The research is supported by several EU programmes, including...

  19. Preparation of thin Si:H films in an inductively coupled plasma reactor and analysis of their surface roughness

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Wenfeng [School of Physics and Telecommunication Engineering, Laboratory of Quantum Information Technology, South China Normal University, Guangzhou 510006 (China); College of Engineering, South China Agricultural University, Guangzhou 510642 (China); Chen Junfang, E-mail: chenjf@scnu.edu.cn [School of Physics and Telecommunication Engineering, Laboratory of Quantum Information Technology, South China Normal University, Guangzhou 510006 (China); Meng Ran; Wang Yang; Wang Hui; Guo Chaofeng; Xue Yongqi [School of Physics and Telecommunication Engineering, Laboratory of Quantum Information Technology, South China Normal University, Guangzhou 510006 (China)

    2010-01-15

    An important concern in the deposition of Si:H films is to obtain smooth surfaces. Herein, we deposit the thin Si:H films using Ar-diluted SiH{sub 4} as feedstock gas in an inductively coupled plasma reactor. And we carry a real-time monitor on the deposition process by using optical emission spectrum technology in the vicinity of substrate and diagnose the Ar plasma radial distribution by Langmuir probe. Surface detecting by AFM and surface profilometry in large scale shows that the thin Si:H films have small surface roughness. Distributions of both the ion density and the electron temperature are homogeneous at h = 0.5 cm. Based on these experimental results, it can be proposed inductively coupled plasma reactor is fit to deposit the thin film in large scale. Also, Ar can affect the reaction process and improve the thin Si:H films characteristics.

  20. Manufacturing of glassy thin shell for adaptive optics: results achieved

    Science.gov (United States)

    Poutriquet, F.; Rinchet, A.; Carel, J.-L.; Leplan, H.; Ruch, E.; Geyl, R.; Marque, G.

    2012-07-01

    Glassy thin shells are key components for the development of adaptive optics and are part of future & innovative projects such as ELT. However, manufacturing thin shells is a real challenge. Even though optical requirements for the front face - or optical face - are relaxed compared to conventional passive mirrors, requirements concerning thickness uniformity are difficult to achieve. In addition, process has to be completely re-defined as thin mirror generates new manufacturing issues. In particular, scratches and digs requirement is more difficult as this could weaken the shell, handling is also an important issue due to the fragility of the mirror. Sagem, through REOSC program, has recently manufactured different types of thin shells in the frame of European projects: E-ELT M4 prototypes and VLT Deformable Secondary Mirror (VLT DSM).

  1. Nonlinear optical properties of Au/PVP composite thin films

    Institute of Scientific and Technical Information of China (English)

    Shen Hong; Cheng Bo-Lin; Lu Guo-Wei; Wang Wei-Tian; Guan Dong-Yi; Chen Zheng-Hao; Yang Guo-Zhen

    2005-01-01

    Colloidal Au and poly(vinylpyrrolidone) (PVP) composite thin films are fabricated by spin-coating method. Linear optical absorption measurements of the Au/PVP composite films indicate an absorption peak around 530 nm due to the surface plasmon resonance of gold nanoparticles. Nonlinear optical properties are studied using standard Z-scan technique, and experimental results show large optical nonlinearities of the Au/PVP composite films. A large value of films.

  2. Optical and dielectric properties of double helix DNA thin films

    Energy Technology Data Exchange (ETDEWEB)

    Soenmezoglu, Savas, E-mail: svssonmezoglu@kmu.edu.tr [Department of Physics, Faculty of Kamil Ozdag Science, Karamanoglu Mehmetbey University, 70100, Karaman (Turkey); Ates Soenmezoglu, Ozlem [Department of Biology, Faculty of Kamil Ozdag Science, Karamanoglu Mehmetbey University, 70100, Karaman (Turkey)

    2011-12-01

    In this work, the thin film of wheat DNA was deposited by spin-coating technique onto glass substrate, and the optical and dielectric properties of the double helix DNA thin film were investigated. The optical constants such as refractive index, extinction coefficient, dielectric constant, dissipation factor, relaxation time, and optical conductivity were determined from the measured transmittance spectra in the wavelength range 190-1100 nm. Meanwhile, the dispersion behavior of the refractive index was studied in terms of the single oscillator Wemple-DiDomenico (W-D) model, and the physical parameters of the average oscillator strength, average oscillator wavelength, average oscillator energy, the refractive index dispersion parameter and the dispersion energy were achieved. Furthermore, the optical band gap values were calculated by W-D model and Tauc model, respectively, and the values obtained from W-D model are in agreement with those determined from the Tauc model. The analysis of the optical absorption data indicates that the optical band gap E{sub g} was indirect transitions. These results provide some useful references for the potential application of the DNA thin films in fiber optic, solar cell and optoelectronic devices. Highlights: {yields} The optical constants of DNA in full UV-vis spectrum were determined. {yields} The change in optical and dielectric property demonstrates that this material has potential to be used as a novel technology. {yields} DNA shows promise to be more suitable material than other materials currently being used for photonic devices.

  3. Crednerite-CuMnO{sub 2} thin films prepared using atmospheric pressure plasma annealing

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hong-Ying, E-mail: hychen@cc.kuas.edu.tw [Department of Chemical and Materials Engineering, National Kaohsiung University of Applied Sciences, 415 Chiken Kuang Road, Kaohsiung 807, Taiwan, ROC (China); Lin, Yu-Chang [Department of Chemical and Materials Engineering, National Kaohsiung University of Applied Sciences, 415 Chiken Kuang Road, Kaohsiung 807, Taiwan, ROC (China); Lee, Jiann-Shing [Department of Applied Physics, National Pingtung University, 4-18 Minsheng Road, Pingtung City 900, Taiwan, ROC (China)

    2015-05-30

    Highlights: • Crednerite-CuMnO{sub 2} thin films were formed at atmospheric pressure plasma with N{sub 2}–(5–10)%O{sub 2}. • The binding energy of Cu-2p spectrum of the crednerite-CuMnO{sub 2} thin films was 932.3 eV (Cu{sup +}). • The binding energies of Mn-3p spectrum were 48.1 ± 0.2 eV (Mn{sup 3+}) and 50.0 ± 0.2 eV (Mn{sup 4+}). • The cation distribution in the crednerite-CuMnO{sub 2} thin films was Cu{sub 1.0}{sup +}(Mn{sub 0.6}{sup 3+}Mn{sub 0.4}{sup 4+})O{sub 2}. • The electrical conductivity of CuMnO{sub 2} thin films was (2.61–2.65) × 10{sup 4} Ω cm. - Abstract: This study reports the preparation of crednerite-CuMnO{sub 2} thin films using atmospheric pressure plasma annealing. The pristine thin films were deposited onto a quartz substrate using the sol–gel process. The specimens were then annealed using atmospheric pressure plasma at N{sub 2}–(0–20%)O{sub 2} for 20 min. Crednerite-CuMnO{sub 2} thin films were obtained using atmospheric pressure plasma annealing at N{sub 2}–5%O{sub 2} and N{sub 2}–10%O{sub 2}. The lattice parameters of the thin films were a = 0.5574–0.5580 nm, b = 0.2874–0.2879 nm, c = 0.5878–0.5881 nm, and β = 104.15–104.25°, which agree well with previous reports. The Raman shifts of the crednerite-CuMnO{sub 2} thin films were 688 ± 2 cm{sup −1}, 381 ± 2 cm{sup −1}, and 314 ± 2 cm{sup −1}. The binding energy of Cu-2p spectrum of the crednerite-CuMnO{sub 2} thin films was 932.3 ± 0.2 eV representing the Cu{sup +} in the thin films. The binding energies of Mn-3p spectrum were 48.1 ± 0.2 eV (Mn{sup 3+}) and 50.0 ± 0.2 eV (Mn{sup 4+}). Furthermore, the cation distribution in the thin films was Cu{sup +}{sub 1.0}(Mn{sup 3+}{sub 0.6}Mn{sup 4+}{sub 0.4})O{sub 2} from the X-ray photoelectron spectroscopy measurement. When the crednerite-CuMnO{sub 2} phase was formed, the surface morphology exhibited a compact/dense granular morphology. The optical bandgap of the crednerite-CuMnO{sub 2} thin

  4. Comparative study of structural and optical properties of pulsed and RF plasma polymerized aniline films

    Energy Technology Data Exchange (ETDEWEB)

    Barman, Tapan; Pal, Arup R., E-mail: arpal@iasst.gov.in; Chutia, Joyanti

    2014-09-15

    Graphical abstract: - Highlights: • Pulse DC and RF plasma is used for synthesis of conducting polymer films. • Conjugated structure retention is better at optimum powers in both the processes. • Conjugated structure retention is better in case of RF plasma prepared films. • Band gap is lower in case of RF plasma prepared films at higher power. • Defect in pulse plasma prepared film is less than RF plasma prepared thin films. - Abstract: Plasma polymerization of aniline is carried out by means of continuous RF and pulsed DC glow discharge plasma in a common reactor at different applied powers. The discharge control variables are optimized for good quality film growth and the role of fragmentation of the molecular structure on the structural, optical, morphological and optophysical properties of the deposited plasma polymerized aniline (PPAni) layers is investigated. Retention of the conjugated structure is found to be prominent at optimum applied power to the plasma in both the continuous RF and pulsed DC polymerization techniques. Improvement in conjugated structure and chain length have been observed in both the continuous RF and pulse DC PPAni thin films with the increase in applied power to the plasma up to a certain limit of applied power when working pressure is fixed at 0.15 mbar. A decrease in optical bandgap with the increase in applied power to the plasma is observed in both the pulsed DC and RF PPAni thin films, but it is more significant in case of RF PPAni films. The plasma polymerized aniline thin films are found to emit photoluminescence due to band to band transition and defects generated in the structure.

  5. Effect of hydrogen addition on the deposition of titanium nitride thin films in nitrogen added argon magnetron plasma

    Science.gov (United States)

    Saikia, P.; Bhuyan, H.; Diaz-Droguett, D. E.; Guzman, F.; Mändl, S.; Saikia, B. K.; Favre, M.; Maze, J. R.; Wyndham, E.

    2016-06-01

    The properties and performance of thin films deposited by plasma assisted processes are closely related to their manufacturing techniques and processes. The objective of the current study is to investigate the modification of plasma parameters occurring during hydrogen addition in N2  +  Ar magnetron plasma used for titanium nitride thin film deposition, and to correlate the measured properties of the deposited thin film with the bulk plasma parameters of the magnetron discharge. From the Langmuir probe measurements, it was observed that the addition of hydrogen led to a decrease of electron density from 8.6 to 6.2  ×  (1014 m-3) and a corresponding increase of electron temperature from 6.30 to 6.74 eV. The optical emission spectroscopy study reveals that with addition of hydrogen, the density of argon ions decreases. The various positive ion species involving hydrogen are found to increase with increase of hydrogen partial pressure in the chamber. The thin films deposited were characterized using standard surface diagnostic tools such as x-ray photoelectron spectroscopy (XPS), secondary ion mass spectrometry (SIMS), x-ray diffraction (XRD), Raman spectroscopy (RS), scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS). Although it was possible to deposit thin films of titanium nitride with hydrogen addition in nitrogen added argon magnetron plasma, the quality of the thin films deteriorates with higher hydrogen partial pressures.

  6. Structuring of DLC:Ag nanocomposite thin films employing plasma chemical etching and ion sputtering

    Science.gov (United States)

    Tamulevičius, Tomas; Tamulevičienė, Asta; Virganavičius, Dainius; Vasiliauskas, Andrius; Kopustinskas, Vitoldas; Meškinis, Šarūnas; Tamulevičius, Sigitas

    2014-12-01

    We analyze structuring effects of diamond like carbon based silver nanocomposite (DLC:Ag) thin films by CF4/O2 plasma chemical etching and Ar+ sputtering. DLC:Ag films were deposited employing unbalanced reactive magnetron sputtering of silver target with Ar+ in C2H2 gas atmosphere. Films with different silver content (0.6-12.9 at.%) were analyzed. The films (as deposited and exposed to plasma chemical etching) were characterized employing scanning electron microscopy and energy dispersive X-ray analysis (SEM/EDS), optical microscopy, ultraviolet-visible light (UV-VIS) spectroscopy and Fourier transform infrared (FTIR) spectroscopy. After deposition, the films were plasma chemically etched in CF4/O2 mixture plasma for 2-6 min. It is shown that optical properties of thin films and silver nano particle size distribution can be tailored during deposition changing the magnetron current and C2H2/Ar ratio or during following plasma chemical etching. The plasma etching enabled to reveal the silver filler particle size distribution and to control silver content on the surface that was found to be dependent on Ostwald ripening process of silver nano-clusters. Employing contact lithography and 4 μm period mask in photoresist or aluminum the films were patterned employing CF4/O2 mixture plasma chemical etching, direct Ar+ sputtering or combined etching processes. It is shown that different processing recipes result in different final grating structures. Selective carbon etching in CF4/O2 gas mixture with photoresist mask revealed micrometer range lines of silver nanoparticles, while Ar+ sputtering and combined processing employing aluminum mask resulted in nanocomposite material (DLC:Ag) micropatterns.

  7. Optics and Plasma Research Department. Annual progress report for 2004

    Energy Technology Data Exchange (ETDEWEB)

    Bindslev, H.; Lynov, J.P.; Pedersen, C.; Petersen, P.M.; Skaarup, B. (eds.)

    2005-03-01

    The Optics and Plasma Research Department performs basic and applied research within three scientific programmes: (1) laser systems and optical materials, (2) optical diagnostics and information processing and (3) plasma physics and technology. The department has core competencies in optical sensors, optical materials, biophotonics, fusion plasma physics, and industrial plasma technology. The department employs key technologies in micro- and nanotechnology for optical systems, temperature calibration, and infrared measurement techniques. The research is supported by several EU programmes, including EURATOM, by Danish research councils and by industry. A summary of the activities in 2004 is presented. (au)

  8. Influence of bias voltage on structural and optical properties of TiNx thin films

    Science.gov (United States)

    Singh, Omveer; Dahiya, Raj P.; Malik, Hitendra K.; Kumar, Parmod

    2015-08-01

    In the present work, Ti thin films were deposited on Si substrate using DC sputtering technique. Indigenous hot cathode arc discharge plasma system was used for nitriding over these samples, where the plasma parameters and work piece can be controlled independently. A mixture of H2 and N2 gases (in the ratio of 80:20) was supplied into the plasma chamber. The effect of bias voltage on the crystal structure, morphology and optical properties was investigated by employing various physical techniques such as X-ray Diffraction, Atomic Force Microscopy and UV-Vis spectrometry. It was found that bias voltage affects largely the crystal structure and band gap which in turn is responsible for the modifications in optical properties of the deposited films.

  9. Hydrophobic plasma polymerized hexamethyldisilazane thin films: characterization and uses

    Directory of Open Access Journals (Sweden)

    Alexsander Tressino de Carvalho

    2006-03-01

    Full Text Available Hexametildisilazane (HMDS plasma polymerized thin films obtained using low frequency power supplies can be used to make adsorbent films and turn surfaces hydrophobic. The aim of this work was to verify the hydrophobicity and adsorption properties of HMDS thin films (with and without the addition of oxygen, resulting in double or single layer films obtained using an inductive reactor powered with a 13.56 MHz power supply. Single and double layer thin films were deposited on silicon for film characterization, polypropylene (PP for ultraviolet (UVA/UVC resistance tests, piezoelectric quartz crystal for adsorption tests. The double layer (intermixing of HMDS plasma polymerized films and HMDS plasma oxidized surfaces showed a non-continuous layer. The films showed good adhesion to all substrates. Infrared analysis showed the presence of CHn, SiCH3, SiNSi and SiCH2Si within the films. Contact angle measurements with water showed hydrophobic surfaces. UVA/UVC exposure of the films resulted in the presence of cross-linking on carbonic radicals and SiCH2Si formation, which resulted in a possible protection of PP against UVA/UVC for a duration of up to two weeks. Adsorption tests showed that all organic reactants were adsorbed but not water. Plasma etching (PE using O2 showed that even after 15 minutes of exposure the films do not change their hydrophobic characteristic but were oxidized. The results point out that HMDS films can be used: for ultraviolet protection of flexible organic substrates, such as PP, for sensor and/or preconcentrator development, due to their adsorption properties, and in spatial applications due to resistance for O2 attack in hostile conditions, such as plasma etching.

  10. The Physics of Thin Film Optical Spectra An Introduction

    CERN Document Server

    Stenzel, Olaf

    2005-01-01

    The book is intended to bridge the gap between fundamental physics courses (such as optics, electrodynamics, quantum mechanics and solid state physics) and highly specialized literature on the spectroscopy, design, and application of optical thin film coatings. Basic knowledge from the above-mentioned courses is therefore presumed. Starting from fundamental physics, the book enables the reader derive the theory of optical coatings and to apply it to practically important spectroscopic problems. Both classical and semiclassical approaches are included. Examples describe the full range of classical optical coatings in various spectral regions as well as highly specialized new topics such as rugate filters and resonant grating waveguide structures.

  11. Sol-gel deposition and plasma treatment of intrinsic, aluminum-doped, and gallium-doped zinc oxide thin films as transparent conductive electrodes

    Science.gov (United States)

    Zhu, Zhaozhao; Mankowski, Trent; Balakrishnan, Kaushik; Shikoh, Ali Sehpar; Touati, Farid; Benammar, Mohieddine A.; Mansuripur, Masud; Falco, Charles M.

    2015-09-01

    Zinc oxide and aluminum/gallium-doped zinc oxide thin films were deposited via sol-gel spin-coating technique. Employing plasma treatment as alternative to post thermal annealing, we found that the morphologies of these thin films have changed and the sheet resistances have been significantly enhanced. These plasma-treated thin films also show very good optical properties, with transmittance above 90% averaged over the visible wavelength range. Our best aluminum/gallium-doped zinc oxide thin films exhibit sheet resistances (Rs) of ~ 200 Ω/sq and ~ 150 Ω/sq, respectively.

  12. An optical analysis tool for avoiding dust formation in VHF hydrogen diluted silane plasmas at low substrate temperatures

    NARCIS (Netherlands)

    de Jong, M.M.; de Koning, J.; Rath, J.K.; Schropp, R.E.I.

    2012-01-01

    Control of the formation of dust particles in a silane deposition plasma is very important for avoiding electrical shunts in devices, such as thin film silicon solar cells. In this work we present a noninvasive in situ method for identification of the plasma regime, based on optical emission spectro

  13. Plasma-etched nanostructures for optical applications (Presentation Recording)

    Science.gov (United States)

    Schulz, Ulrike; Rickelt, Friedrich; Munzert, Peter; Kaiser, Norbert

    2015-08-01

    A basic requirement for many optical applications is the reduction of Fresnel-reflections. Besides of interference coatings, nanostructures with sub-wavelength size as known from the eye of the night-flying moth can provide antireflective (AR) properties. The basic principle is to mix a material with air on a sub-wavelength scale to decrease the effective refractive index. To realize AR nanostructures on polymers, the self-organized formation of stochastically arranged antireflective structures using a low-pressure plasma etching process was studied. An advanced procedure involves the use of additional deposition of a thin oxide layer prior etching. A broad range of different structure morphologies exhibiting antireflective properties can be generated on almost all types of polymeric materials. For applications on glass, organic films are used as a transfer medium. Organic layers as thin film materials were evaluated to identify compounds suitable for forming nanostructures by plasma etching. The vapor deposition and etching of organic layers on glass offers a new possibility to achieve antireflective properties in a broad spectral range and for a wide range of light incidence.

  14. High density plasma reactive ion etching of Ru thin films using non-corrosive gas mixture

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Su Min; Garay, Adrian Adalberto; Lee, Wan In; Chung, Chee Won, E-mail: cwchung@inha.ac.kr

    2015-07-31

    Inductively coupled plasma reactive ion etching (ICPRIE) of Ru thin films patterned with TiN hard masks was investigated using a CH{sub 3}OH/Ar gas mixture. As the CH{sub 3}OH concentration in CH{sub 3}OH/Ar increased, the etch rates of Ru thin films and TiN hard masks decreased. However, the etch selectivity of Ru films on TiN hard masks increased and the etch slope of Ru film improved at 25% CH{sub 3}OH/Ar. With increasing ICP radiofrequency power and direct current bias voltage and decreasing process pressure, the etch rates of Ru films increased, and the etch profiles were enhanced without redeposition on the sidewall. Optical emission spectroscopy and X-ray photoelectron spectroscopy were employed to analyze the plasma and surface chemistry. Based on these results, Ru thin films were oxidized to RuO{sub 2} and RuO{sub 3} compounds that were removed by sputtering of ions and the etching of Ru thin films followed a physical sputtering with the assistance of chemical reaction. - Highlights: • Etching of Ru films in CH{sub 3}OH/Ar was investigated. • High selectivity and etch profile with high degree of anisotropy were obtained. • XPS analysis was examined to identify the etch chemistry. • During etching Ru was oxidized to RuO{sub 2} and RuO{sub 3} can be easily sputtered off.

  15. Optical properties of nanostructured InSe thin films

    Science.gov (United States)

    El-Nahass, M. M.; Saleh, Abdul-Basit A.; Darwish, A. A. A.; Bahlol, M. H.

    2012-03-01

    Thin films of InSe were prepared by thermal evaporation technique. The as-deposited films have nano-scale crystalline nature and the annealing enhanced the degree of crystallinity. The optical properties of nanocrystalline thin films of InSe were studied using spectrophotometric measurements of transmittance, T, and reflectance, R, at normal incidence of light in the wavelength range 200-2500 nm. The optical constants (refractive index, n, and absorption index, k) were calculated using a computer program based on Murmann's exact equations. The calculated optical constants are independent of the film thickness. The optical dispersion parameters have been analysed by single oscillator model. The type of transition in InSe films is indirect allowed with a value of energy gap equals to 1.10 eV, which increased to 1.23 eV upon annealing.

  16. Plasma spectroscopy using optical vortex laser

    Science.gov (United States)

    Yoshimura, Shinji; Aramaki, Mitsutoshi; Terasaka, Kenichiro; Toda, Yasunori; Czarnetzki, Uwe; Shikano, Yutaka

    2014-10-01

    Laser spectroscopy is a useful tool for nonintrusive plasma diagnostics; it can provide many important quantities in a plasma such as temperature, density, and flow velocity of ions and neutrals from the spectrum obtained by scanning the frequency of narrow bandwidth laser. Obtainable information is, however, limited in principle to the direction parallel to the laser path. The aim of this study is to introduce a Laguerre-Gaussian beam, which is called as optical vortex, in place of a widely used Hermite-Gaussian beam. One of the remarkable properties of the Laguerre-Gaussian beam is that it carries an angular momentum in contrast to the Hermite-Gaussian beam. It follows that particles in the laser beam feel the Doppler effect even in the transverse direction of the laser path. Therefore it is expected that the limitation imposed by the laser path can be overcome by using an optical vortex laser. The concept of optical vortex spectroscopy, the development of the laser system, and some preliminary results of a proof-of-principle experiment will be presented. This work is performed with the support and under the auspices of NINS young scientists collaboration program for cross-disciplinary study, NIFS collaboration research program (NIFS13KOAP026), and JSPS KAKENHI Grant Number 25287152.

  17. Nanocomposite thin films for optical temperature sensing

    Energy Technology Data Exchange (ETDEWEB)

    Ohodnicki, Jr., Paul R.; Brown, Thomas D.; Buric, Michael P.; Matranga, Christopher

    2017-02-14

    The disclosure relates to an optical method for temperature sensing utilizing a temperature sensing material. In an embodiment the gas stream, liquid, or solid has a temperature greater than about 500.degree. C. The temperature sensing material is comprised of metallic nanoparticles dispersed in a dielectric matrix. The metallic nanoparticles have an electronic conductivity greater than approximately 10.sup.-1 S/cm at the temperature of the temperature sensing material. The dielectric matrix has an electronic conductivity at least two orders of magnitude less than the dispersed metallic nanoparticles at the temperature of the temperature sensing material. In some embodiments, the chemical composition of a gas stream or liquid is simultaneously monitored by optical signal shifts through multiple or broadband wavelength interrogation approaches. In some embodiments, the dielectric matrix provides additional functionality due to a temperature dependent band-edge, an optimized chemical sensing response, or an optimized refractive index of the temperature sensing material for integration with optical waveguides.

  18. Homogenization studies for optical sensors based on sculptured thin films

    OpenAIRE

    Jamaian, Siti Suhana

    2013-01-01

    In this thesis we investigate theoretically various types of sculptured thin film (STF) envisioned as platforms for optical sensing. A STF consists of an array of parallel nanowires which can be grown on a substrate using vapour deposition techniques. Typically, each nanowire has a diameter in the range from ~ 10-300 nmwhile the film thickness is ~

  19. Plasma synthesis of rare earth doped integrated optical waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Raoux, S.; Anders, S.; Yu, K.M.; Brown, I.G. [Lawrence Berkeley Lab., CA (United States); Ivanov, I.C. [Charles Evans & Associates, Redwood City, CA (United States)

    1995-03-01

    We describe a novel means for the production of optically active planar waveguides. The makes use of a low energy plasma deposition. Cathodic-arc-produced metal plasmas the metallic components of the films and gases are added to form compound films. Here we discuss the synthesis of Al{sub 2{minus}x}ER{sub x}O{sub 3} thin films. The erbium concentration (x) can vary from 0 to 100% and the thickness of the film can be from Angstroms to microns. In such material, at high active center concentration (x=l% to 20%), erbium ions give rise to room temperature 1.53{mu}m emission which has minimum loss in silica-based optical fibers. With this technique, multilayer integrated planar waveguide structures can be grown, such as Al{sub 2}O{sub 3}/Al{sub 2{minus}x}Er{sub x}O{sub 3}/Al{sub 2}O{sub 3}/Si, for example.

  20. Structural and Optical Properties of Nanoscale Galinobisuitite Thin Films

    Directory of Open Access Journals (Sweden)

    Omar H. Abd-Elkader

    2014-01-01

    Full Text Available Galinobisuitite thin films of (Bi2S3(PbS were prepared using the chemical bath deposition technique (CBD. Thin films were prepared by a modified chemical deposition process by allowing the triethanolamine (TEA complex of Bi3+ and Pb2+ to react with S2− ions, which are released slowly by the dissociation of the thiourea (TU solution. The films are polycrystalline and the average crystallite size is 35 nm. The composition of the films was measured using the atomic absorption spectroscopy (AAS technique. The films are very adherent to the substrates. The crystal structure of Galinobisuitite thin films was calculated by using the X-ray diffraction (XRD technique. The surface morphology and roughness of the films were studied using scanning electron microscopes (SEM, transmission electron microscopes (TEM and stylus profilers respectively. The optical band gaps of the films were estimated from optical measurements.

  1. Optical and Structural Properties of Ultra-thin Gold Films

    CERN Document Server

    Kossoy, Anna; Simakov, Denis; Leosson, Kristjan; Kéna-Cohen, Stéphane; Maier, Stefan A

    2014-01-01

    Realizing laterally continuous ultra-thin gold films on transparent substrates is a challenge of significant technological importance. In the present work, formation of ultra-thin gold films on fused silica is studied, demonstrating how suppression of island formation and reduction of plasmonic absorption can be achieved by treating substrates with (3-mercaptopropyl) trimethoxysilane prior to deposition. Void-free fi lms with deposition thickness as low as 5.4 nm are realized and remain structurally stable at room temperature. Based on detailed structural analysis of the fi lms by specular and diffuse X-ray reflectivity measurements, it is shown that optical transmission properties of continuous ultra-thin films can be accounted for using the bulk dielectric function of gold. However, it is important to take into account the non-abrupt transition zone between the metal and the surrounding dielectrics, which extends through several lattice constants for the laterally continuous ultra-thin films (film thickness...

  2. Optical properties of rubrene thin film prepared by thermal evaporation

    Institute of Scientific and Technical Information of China (English)

    陈亮; 邓金祥; 孔乐; 崔敏; 陈仁刚; 张紫佳

    2015-01-01

    Rubrene thin films are deposited on quartz substrates and silver nanoparticles (Ag NPs) films by the thermal evapo-ration technique. The optical properties of rubrene thin film are investigated in a spectral range of 190 nm–1600 nm. The analysis of the absorption coefficient (α) reveals direct allowed transition with a corresponding energy of 2.24 eV. The photoluminescence (PL) peak of the rubrene thin film is observed to be at 563 nm (2.21 eV). With the use of Ag NPs which are fabricated by radio-frequency (RF) magnetron sputtering on the quartz, the PL intensity is 8.5 times that of as-deposited rubrene thin film. It is attributed to the fact that the surface plasmon enhances the photoluminescence.

  3. Development of plasma bolometers using fiber-optic temperature sensors

    Energy Technology Data Exchange (ETDEWEB)

    Reinke, M. L., E-mail: reinkeml@ornl.gov [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Han, M.; Liu, G. [University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (United States); Eden, G. G. van [Dutch Institute for Fundamental Energy Research, De Zaale 20, 5612 AJ Eindhoven (Netherlands); Evenblij, R.; Haverdings, M. [Technobis, Pyrietstraat 2, 1812 SC Alkmaar (Netherlands); Stratton, B. C. [Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543 (United States)

    2016-11-15

    Measurements of radiated power in magnetically confined plasmas are important for exhaust studies in present experiments and expected to be a critical diagnostic for future fusion reactors. Resistive bolometer sensors have long been utilized in tokamaks and helical devices but suffer from electromagnetic interference (EMI). Results are shown from initial testing of a new bolometer concept based on fiber-optic temperature sensor technology. A small, 80 μm diameter, 200 μm long silicon pillar attached to the end of a single mode fiber-optic cable acts as a Fabry–Pérot cavity when broadband light, λ{sub o} ∼ 1550 nm, is transmitted along the fiber. Changes in temperature alter the optical path length of the cavity primarily through the thermo-optic effect, resulting in a shift of fringes reflected from the pillar detected using an I-MON 512 OEM spectrometer. While initially designed for use in liquids, this sensor has ideal properties for use as a plasma bolometer: a time constant, in air, of ∼150 ms, strong absorption in the spectral range of plasma emission, immunity to local EMI, and the ability to measure changes in temperature remotely. Its compact design offers unique opportunities for integration into the vacuum environment in places unsuitable for a resistive bolometer. Using a variable focus 5 mW, 405 nm, modulating laser, the signal to noise ratio versus power density of various bolometer technologies are directly compared, estimating the noise equivalent power density (NEPD). Present tests show the fiber-optic bolometer to have NEPD of 5-10 W/m{sup 2} when compared to those of the resistive bolometer which can achieve <0.5 W/m{sup 2} in the laboratory, but this can degrade to 1-2 W/m{sup 2} or worse when installed on a tokamak. Concepts are discussed to improve the signal to noise ratio of this new fiber-optic bolometer by reducing the pillar height and adding thin metallic coatings, along with improving the spectral resolution of the interrogator.

  4. Optical properties of chalcogenide Ge-Te-In thin films

    Science.gov (United States)

    Zaidan, A.; Ivanova, V.; Petkov, P.

    2012-03-01

    Thin films of the chalcogenide (GeTe4)1-xInx with various compositions (x = 0, 5, 10, 15, 20 at %) were deposited under vacuum on glass substrates by thermal evaporation. The optical transmission and reflection spectra of the films at normal incidence were investigated in the spectral range from 800 to 2600 nm. Using the transmission spectra, the optical constants (refractive index (n) and extinction coefficient (k)) were calculated based on Swanepoel's method. The optical band gap (Egopt) was also estimated using Tauc's extrapolation procedure.

  5. Comparison of Plasma Activation of Thin Water Layers by Direct and Remote Plasma Sources

    Science.gov (United States)

    Kushner, Mark

    2014-10-01

    Plasma activation of liquids is now being investigated for a variety of biomedical applications. The plasma sources used for this activation can be generally classified as direct (the plasma is in contact with the surface of the liquid) or remote (the plasma does not directly touch the liquid). The direct plasma source may be a dielectric barrier discharge (DBD) where the surface of the liquid is a floating electrode or a plasma jet in which the ionization wave forming the plasma plume reaches the liquid. The remote plasma source may be a DBD with electrodes electrically isolated from the liquid or a plasma jet in which the ionization wave in the plume does not reach the liquid. In this paper, a comparison of activation of thin water layers on top of tissue, as might be encountered in wound healing, will be discussed using results from numerical investigations. We used the modeling platform nonPDPSIM to simulate direct plasma activation of thin water layers using DBDs and remote activation using plasma jets using up to hundreds of pulses. The DBDs are sustained in humid air while the plasma jets consist of He/O2 mixtures flowed into humid air. For similar number of pulses and energy deposition, the direct DBD plasma sources produce more acidification and higher production of nitrates/nitrites in the liquid. This is due to the accumulation of NxOy plasma jets, the convective flow removes many of these species prior to their diffusing into the water or reacting to form higher nitrogen oxides. This latter effect is sensitive to the repetition rate which determines whether reactive species formed during prior pulses overlap with newly produced reactive species. in the gas phase. In the plasma jets, the convective flow removes many of these species prior to their diffusing into the water or reacting to form higher nitrogen oxides. This latter effect is sensitive to the repetition rate which determines whether reactive species formed during prior pulses overlap with

  6. 3-D Magnetospheric Field and Plasma Containing Thin Current Sheets

    Science.gov (United States)

    Zaharia, S.; Cheng, C. Z.; Maezawa, K.; Wing, S.

    2002-05-01

    In this study we present fully-3D self-consistent solutions of the magnetosphere by using observation-based plasma pressure distributions and computational boundary conditions based on the T96 magnetospheric field model. The pressure profiles we use are either taken directly from observations (GEOTAIL pressure data in the plasma sheet and DMSP ionospheric pressure) or empirical (Spence-Kivelson formula for pressure on the midnight equatorial line). The 3-D solutions involve solving 2 coupled elliptic equations in a flux coordinate systems, with the magnetic field expressed by two Euler potentials and using appropriate boundary conditions for both the closed- and open-field regions derived from the empirical field model. We look into how the self-consistent magnetic field and current structures change under different external conditions, and we discuss the appearance of thin cross-tail current sheets during disturbed magnetospheric times.

  7. Are spiral galaxies optically thin or thick?

    CERN Document Server

    Xilouris, E M; Kylafis, N D; Paleologou, E V; Papamastorakis, J

    1999-01-01

    The opacity of spiral galaxies is examined by modelling the dust and stellar content of individual galaxies. The model is applied to five late-type spiral galaxies (NGC 4013, IC 2531, UGC 1082, NGC 5529 and NGC 5907). Having analyzed a total of seven galaxies thus far, the five galaxies mentioned above plus UGC 2048 and NGC 891 presented in (Xilouris et al. 1997, 1998), we are able to draw some general conclusions, the most significant of which are: 1) The face-on central optical depth is less than one in all optical bands indicating that typical spiral galaxies like the ones that we have modelled would be completely transparent if they were to be seen face-on. 2) The dust scaleheight is about half that of the stars, which means that the dust is more concentrated near the plane of the disk. 3) The dust scalelength is about 1.4 times larger than that of the stars and the dust is more radially extended than the stars. 4) The dust mass is found to be about an order of a magnitude more than previously measured us...

  8. Optical properties of thin nanosilicon films

    Science.gov (United States)

    Buchenko, Viktor V.; Rodionova, Tatiana V.; Sutyagina, Anastasia S.; Goloborodko, Andrey A.; Multian, Volodymyr V.; Uklein, Andrii V.; Gayvoronsky, Volodymyr Ya.

    2016-12-01

    Present paper is devoted to the investigation of the nanosilicon films internal structure effect on optical properties. Atomic force microscopy results reveal that the films with different thickness have fundamentally different grain size distribution (samples with the film thickness less than 50 nm have single-mode grain size distribution, while samples with the film thickness more than 50 nm have multi-mode distribution of grain size). The correlation between grain size of nanosilicon films, photoluminescence and scattering indicatrix was shown. Well-isolated vibronic structures were observed on the ultraviolet-visible photoluminescence spectrum from nanosilicon films with the thickness more than 10 nm. The photoluminescence spectra in the red range correlate with the nanosilicon grain size distribution due to the effect of the quantum confinement. However, due to the complex shape of the grains mathematical modeling of photoluminescence spectrum is complicated. Both scattering indicatrix and photoluminescence reveal the multi-mode grain size distribution of the films with thickness more than 50 nm. The comparative analysis of theoretical results of optical radiation scattering by nanosilicon films with experimental ones is illustrated. Mathematical modeling of the scattering indicatrix shows the correlation of average grain size from scattering and photoluminescence data.

  9. Thin current sheets caused by plasma flow gradients in space and astrophysical plasma

    Directory of Open Access Journals (Sweden)

    D. H. Nickeler

    2010-08-01

    Full Text Available Strong gradients in plasma flows play a major role in space and astrophysical plasmas. A typical situation is that a static plasma equilibrium is surrounded by a plasma flow, which can lead to strong plasma flow gradients at the separatrices between field lines with different magnetic topologies, e.g., planetary magnetospheres, helmet streamers in the solar corona, or at the boundary between the heliosphere and interstellar medium. Within this work we make a first step to understand the influence of these flows towards the occurrence of current sheets in a stationary state situation. We concentrate here on incompressible plasma flows and 2-D equilibria, which allow us to find analytic solutions of the stationary magnetohydrodynamics equations (SMHD. First we solve the magnetohydrostatic (MHS equations with the help of a Grad-Shafranov equation and then we transform these static equilibria into a stationary state with plasma flow. We are in particular interested to study SMHD-equilibria with strong plasma flow gradients perpendicular to separatrices. We find that induced thin current sheets occur naturally in such situations. The strength of the induced currents depend on the Alfvén Mach number and its gradient, and on the magnetic field.

  10. Coherent control of optical activity and optical anisotropy of thin metamaterials

    CERN Document Server

    Mousavi, Seyedmohammad A; Shi, Jinhui; Zheludev, Nikolay I

    2013-01-01

    The future fibre optic communications network will rely on photons as carriers of information, which may be stored in intensity, polarization or phase of light. However, processing of such optical information usually relies on electronics. Aiming to avoid the conversion between optical and electronic signals, modulation of light with light based on optical nonlinearity has become a major research field, but real integrated all-optical systems face thermal management and energy challenges. On the other hand, it has recently been demonstrated that the interaction of two coherent light beams on a thin, lossy, linear material can lead to large and ultrafast intensity modulation at arbitrarily low power resulting from coherent absorption. Here we demonstrate that birefringence and optical activity (linear and circular birefringence and dichroism) of functional materials can be coherently controlled by placing a thin material slab into a standing wave formed by the signal and control waves. Efficient control of the...

  11. Optical thin-film interference effects in microcantilevers

    Science.gov (United States)

    Wig, A.; Passian, A.; Arakawa, E.; Ferrell, T. L.; Thundat, T.

    2004-02-01

    We report direct observation of thin-film interference effects in microcantilevers, an effect that can impact the optical monitoring of the microcantilever motion. When microcantilevers are illuminated with different wavelengths of light the amount of absorption and the wavelengths of maxima in the absorption depend upon the thickness of the layers, the materials used in the layers, and the direction of illumination. Wavelengths of maximum absorption are observed as microcantilever deflections due to heat-induced bending of the bimaterial structure of the microcantilever. Results are presented for different multilayer configurations and illumination directions. These results are then compared with theoretical calculations based on multilayer thin-film analysis.

  12. Fast Industrial Inspection of Optical Thin Film Using Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Muhammad Faizan Shirazi

    2016-09-01

    Full Text Available An application of spectral domain optical coherence tomography (SD-OCT was demonstrated for a fast industrial inspection of an optical thin film panel. An optical thin film sample similar to a liquid crystal display (LCD panel was examined. Two identical SD-OCT systems were utilized for parallel scanning of a complete sample in half time. Dual OCT inspection heads were utilized for transverse (fast scanning, while a stable linear motorized translational stage was used for lateral (slow scanning. The cross-sectional and volumetric images of an optical thin film sample were acquired to detect the defects in glass and other layers that are difficult to observe using visual inspection methods. The rapid inspection enabled by this setup led to the early detection of product defects on the manufacturing line, resulting in a significant improvement in the quality assurance of industrial products.

  13. Oxygen plasma effects on optical properties of ZnSe films

    Science.gov (United States)

    Yan, Li; Woollam, John A.; Franke, Eva

    2002-05-01

    Zinc selenide is an infrared transparent semiconductor material being considered for use in space as an infrared optical coating. In this work, zinc selenide thin films of different thicknesses were exposed to an electron cyclotron resonance generated oxygen plasma, often used to ``simulate'' the low earth orbital environment. The maximum fluence used in our experiments was equivalent to ~16 years in the low earth orbital environment. ZnSe thin film optical constants (both before and after oxygen plasma exposure) were determined using variable angle spectroscopic ellipsometry from the vacuum ultraviolet at 146 nm through the middle infrared to 40 μm. A parametric dispersion model (Herzinger-Johs) was successfully used to fit the optical data over the entire range from ultraviolet to infrared. Comparing the pre- and post-oxygen plasma exposure data, few changes were observed in the middle infrared region, while drastic changes were seen in the vacuum ultraviolet through visible to near infrared (0.73-8.5 eV). This suggests that chemical changes upon plasma exposure, including oxidation, are found mainly in a thin layer near the surface. As the proposed application is for infrared coatings, and few infrared changes were seen under conditions roughly equivalent to 16 years in low earth orbit, ZnSe may indeed be useful for space infrared applications. Performance simulations of ZnSe coated infrared-operating electrochromic thermal-control surfaces confirm this conclusion.

  14. Cell proliferation on modified DLC thin films prepared by plasma enhanced chemical vapor deposition.

    Science.gov (United States)

    Stoica, Adrian; Manakhov, Anton; Polčák, Josef; Ondračka, Pavel; Buršíková, Vilma; Zajíčková, Renata; Medalová, Jiřina; Zajíčková, Lenka

    2015-06-12

    Recently, diamondlike carbon (DLC) thin films have gained interest for biological applications, such as hip and dental prostheses or heart valves and coronary stents, thanks to their high strength and stability. However, the biocompatibility of the DLC is still questionable due to its low wettability and possible mechanical failure (delamination). In this work, DLC:N:O and DLC: SiOx thin films were comparatively investigated with respect to cell proliferation. Thin DLC films with an addition of N, O, and Si were prepared by plasma enhanced CVD from mixtures of methane, hydrogen, and hexamethyldisiloxane. The films were optically characterized by infrared spectroscopy and ellipsometry in UV-visible spectrum. The thickness and the optical properties were obtained from the ellipsometric measurements. Atomic composition of the films was determined by Rutherford backscattering spectroscopy combined with elastic recoil detection analysis and by x-ray photoelectron spectroscopy. The mechanical properties of the films were studied by depth sensing indentation technique. The number of cells that proliferate on the surface of the prepared DLC films and on control culture dishes were compared and correlated with the properties of as-deposited and aged films. The authors found that the level of cell proliferation on the coated dishes was high, comparable to the untreated (control) samples. The prepared DLC films were stable and no decrease of the biocompatibility was observed for the samples aged at ambient conditions.

  15. Optical Characterization of Porous Sputtered Silver Thin Films

    Directory of Open Access Journals (Sweden)

    Olivier Carton

    2013-01-01

    Full Text Available The optical properties of various porous silver films, grown with a commercial DC sputter coater, were investigated and compared for different plasma parameters. Effective Drude models were successfully used for those films whose spectra did not show particular resonance peaks. For the other films, neither an effective Drude model nor effective medium models (Maxwell Garnett, Bruggeman, and Looyenga can describe the optical properties. It turns out that a more general approach like the Bergman representation describes the optical data of these films accurately adopting porosity values consistent with physical measurements.

  16. Optical limiting effects in nanostructured silicon carbide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Borshch, A A; Starkov, V N; Volkov, V I; Rudenko, V I; Boyarchuk, A Yu [Institute of Physics, National Academy of Sciences of Ukraine, Kiev (Ukraine); Semenov, A V [Institute for Single Crystals of NAS of Ukraine (Ukraine)

    2013-12-31

    We present the results of experiments on the interaction of nanosecond laser radiation at 532 and 1064 nm with nanostructured silicon carbide thin films of different polytypes. We have found the effect of optical intensity limiting at both wavelengths. The intensity of optical limiting at λ = 532 nm (I{sub cl} ∼ 10{sup 6} W cm{sup -2}) is shown to be an order of magnitude less than that at λ = 1064 nm (I{sub cl} ∼ 10{sup 7} W cm{sup -2}). We discuss the nature of the nonlinearity, leading to the optical limiting effect. We have proposed a method for determining the amount of linear and two-photon absorption in material media. (nonlinear optical phenomena)

  17. The physics of thin film optical spectra an introduction

    CERN Document Server

    Stenzel, Olaf

    2016-01-01

    The book bridges the gap between fundamental physics courses (such as optics, electrodynamics, quantum mechanics and solid state physics) and highly specialized literature on the spectroscopy, design, and application of optical thin film coatings. Basic knowledge from the above-mentioned courses is therefore presumed. Starting from fundamental physics, the book enables the reader derive the theory of optical coatings and to apply it to practically important spectroscopic problems. Both classical and semiclassical approaches are included. Examples describe the full range of classical optical coatings in various spectral regions as well as highly specialized new topics such as rugate filters and resonant grating waveguide structures.The second edition has been updated and extended with respect to probing matter in different spectral regions, homogenous and inhomogeneous line broadening mechanisms and the Fresnel formula for the effect of planar interfaces.

  18. Electrical and optical characterization of atomically thin WS₂.

    Science.gov (United States)

    Georgiou, Thanasis; Yang, Huafeng; Jalil, Rashid; Chapman, James; Novoselov, Kostya S; Mishchenko, Artem

    2014-07-21

    Atomically thin layers of materials, which are just a few atoms in thickness, present an attractive option for future electronic devices. Herein we characterize, optically and electronically, atomically thin tungsten disulphide (WS2), a layered semiconductor. We provide the distinctive Raman and photoluminescence signatures for single layers, and prepare field-effect transistors where atomically thin WS2 serves as the conductive channel. The transistors present mobilities μ = 10 cm(2) V(-1) s(-1) and exhibit ON/OFF ratios exceeding 100,000. Our results show that WS2 is an attractive option for applications in electronic and optoelectronic devices and pave the way for further studies in this two-dimensional material.

  19. Optically Thin Metallic Films for High-radiative-efficiency Plasmonics

    CERN Document Server

    Yang, Yi; Hsu, Chia Wei; Miller, Owen D; Joannopoulos, John D; Soljačić, Marin

    2016-01-01

    Plasmonics enables deep-subwavelength concentration of light and has become important for fundamental studies as well as real-life applications. Two major existing platforms of plasmonics are metallic nanoparticles and metallic films. Metallic nanoparticles allow efficient coupling to far field radiation, yet their synthesis typically leads to poor material quality. Metallic films offer substantially higher quality materials, but their coupling to radiation is typically jeopardized due to the large momentum mismatch with free space. Here, we propose and theoretically investigate optically thin metallic films as an ideal platform for high-radiative-efficiency plasmonics. For far-field scattering, adding a thin high-quality metallic substrate enables a higher quality factor while maintaining the localization and tunability that the nanoparticle provides. For near-field spontaneous emission, a thin metallic substrate, of high quality or not, greatly improves the field overlap between the emitter environment and ...

  20. Thin film metal coated fiber optic hydrophone probe.

    Science.gov (United States)

    Gopinath Minasamudram, Rupa; Arora, Piyush; Gandhi, Gaurav; Daryoush, Afshin S; El-Sherif, Mahmoud A; Lewin, Peter A

    2009-11-01

    Our purpose is to improve the performance sensitivity of a fiber sensor used as a fiber optic hydrophone probe (FOHP) by the addition of nanoscale thin film gold coating. The fiber is designed to provide a uniform and spatial averaging free response up to 100 MHz by etching down to an active diameter of approximately 9 mum. The performance sensitivity of straight cleaved (i.e., full size core and cladding) uncoated, tapered uncoated, and tapered thin film gold-coated fiber sensors was compared in the frequency range from 1.5 to 20 MHz in the presence of acoustic amplitude pressure levels as high as 6 MPa. An unprecedented voltage sensitivity of -245 dB relative to 1 V/muPa (560 mV/MPa) was measured for a thin film gold-coated FOHP by optimizing the gold coating thickness.

  1. Hyperspectrally-Resolved Surface Emissivity Derived Under Optically Thin Clouds

    Science.gov (United States)

    Zhou, Daniel K.; Larar, Allen M.; Liu, Xu; Smith, William L.; Strow, L. Larrabee; Yang, Ping

    2010-01-01

    Surface spectral emissivity derived from current and future satellites can and will reveal critical information about the Earth s ecosystem and land surface type properties, which can be utilized as a means of long-term monitoring of global environment and climate change. Hyperspectrally-resolved surface emissivities are derived with an algorithm utilizes a combined fast radiative transfer model (RTM) with a molecular RTM and a cloud RTM accounting for both atmospheric absorption and cloud absorption/scattering. Clouds are automatically detected and cloud microphysical parameters are retrieved; and emissivity is retrieved under clear and optically thin cloud conditions. This technique separates surface emissivity from skin temperature by representing the emissivity spectrum with eigenvectors derived from a laboratory measured emissivity database; in other words, using the constraint as a means for the emissivity to vary smoothly across atmospheric absorption lines. Here we present the emissivity derived under optically thin clouds in comparison with that under clear conditions.

  2. Structural ordering, morphology and optical properties of amorphous Al{sub x}In{sub 1−x}N thin films grown by plasma-assisted dual source reactive evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Alizadeh, M., E-mail: alizadeh_kozerash@yahoo.com [Low Dimensional Materials Research Centre (LDMRC), Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Ganesh, V. [Low Dimensional Materials Research Centre (LDMRC), Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Mehdipour, H. [Plasma Nanoscience @ Complex Systems, The University of Sydney, New South Wales 2006 (Australia); Department of Physics, Sharif University of Technology, Tehran 11155-9161 (Iran, Islamic Republic of); Nazarudin, N.F.F.; Goh, B.T.; Shuhaimi, A. [Low Dimensional Materials Research Centre (LDMRC), Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Rahman, S.A., E-mail: saadah@um.edu.my [Low Dimensional Materials Research Centre (LDMRC), Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2015-05-25

    Highlights: • In-rich and Al-rich Al{sub x}In{sub 1−x}N films were grown by plasma-aided reactive evaporation. • The A{sub 1}(LO) phonon mode of the Al-rich films exhibits two-mode behavior. • The band gap of the films was tuned from 1.08 to 2.50 eV. • A bowing parameter of 4.3 eV was calculated for the grown Al{sub x}In{sub 1−x}N films. • The morphology was changed from clusters to uniformly shaped grains by decreasing x. - Abstract: Amorphous aluminum indium nitride (Al{sub x}In{sub 1−x}N) thin films were deposited on quartz substrates by plasma-assisted dual source reactive evaporation system. In-rich (x = 0.10 and 0.18) and Al-rich (x = 0.60 and 0.64) films were prepared by simply varying an AC voltage applied to indium wire. The X-ray-diffraction patterns revealed a small broad peak assigned to Al{sub 0.10}In{sub 0.90}N (0 0 2) plane, but no perceivable peaks assigned to crystalline Al{sub x}In{sub 1−x}N were observed for the films with x = 0.18, 0.60 and 0.64. The morphology of the film was changed from clusters of small grains to uniformly shaped particles with decrease of x. The band gap energy of the films increased from 1.08 eV to 2.50 eV as the Al composition varied from 0.1 to 0.64. Also, Raman results indicated that E{sub 2}(high) and A{sub 1}(LO) peaks of the Al{sub x}In{sub 1−x}N films are remarkably blue-shifted by increasing x and the A{sub 1}(LO) phonon mode of the Al-rich films exhibits two-mode behavior. A bowing parameter of 4.3 eV was obtained for AlInN films. The extrapolated value from bowing equation was 0.85 eV for band gap energy of InN.

  3. Prism coupling technique investigation of elasto-optical properties of thin polymer films

    NARCIS (Netherlands)

    Ay, Feridun; Kocabas, Askin; Kocabas, Coskun; Aydinli, Atilla; Agan, Sedat

    2004-01-01

    The use of thin polymer films in optical planar integrated optical circuits is rapidly increasing. Much interest, therefore, has been devoted to characterizing the optical and mechanical properties of thin polymer films. This study focuses on measuring the elasto-optical properties of three differen

  4. Thin film detection of High Energy Materials: Optical Pumping Approach

    CERN Document Server

    Barthwal, Sachin

    2014-01-01

    We present our work on High Energy Material detection based on thin film of Lithium using the phenomenon of Optical Pumping. The Li atoms present in the thin film are optically pumped to one of the ground hyperfine energy levels so that they can no more absorb light from the resonant light source. Now in presence of a RF signal, which quantifies the ambient magnetic field, this polarized atomic system is again randomized thus making it reabsorb the resonant light. This gives a quantified measurement of the magnetic field surrounding the thin film detector. This is then mapped to the presence of magnetic HEM and hence the HEM are detected. Our approach in this regard starts with verifying the stability of Lithium atoms in various solvents so as to get a suitable liquid medium to form a thin film. In this regard, various UV-visible characterization spectra are presented to finally approach a stable system for the detection. We have worked on around 10 polar and non- polar solvents to see the stability criteria....

  5. Removal of carbon contaminations by RF plasma generated reactive species and subsequent effects on optical surface

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, P. K., E-mail: praveenyadav@rrcat.gov.in; Rai, S. K.; Modi, M. H.; Nayak, M.; Lodha, G. S. [Indus Synchrotron Utilization Division, Raja Ramanna Centre for Advanced Technology, Indore-452013 (India); Kumar, M.; Chakera, J. A.; Naik, P. A. [Laser Plasma Laboratory, Laser Plasma Division, Raja Ramanna Centre for Advanced Technology, Indore-452013 (India)

    2015-06-24

    Carbon contamination on optical elements is a serious issue in synchrotron beam lines for several decades. The basic mechanism of carbon deposition on optics and cleaning strategies are not fully understood. Carbon growth mechanism and optimized cleaning procedures are worldwide under development stage. Optimized RF plasma cleaning is considered an active remedy for the same. In present study carbon contaminated optical test surfaces (carbon capped tungsten thin film) are exposed for 30 minutes to four different gases, rf plasma at constant power and constant dynamic pressure. Structural characterization (thickness, roughness and density) of virgin samples and plasma exposed samples was done by soft x-ray (λ=80 Å) reflectivity measurements at Indus-1 reflectivity beam line. Different gas plasma removes carbon with different rate (0.4 to 0.65 nm /min). A thin layer 2 to 9 nm of different roughness and density is observed at the top surface of tungsten film. Ar gas plasma is found more suitable for cleaning of tungsten surface.

  6. Thin-film perovskites-ferroelectric materials for integrated optics

    Energy Technology Data Exchange (ETDEWEB)

    Walker, F.J. [Univ. of Tennessee, Knoxville, TN (United States)]|[Oak Ridge National Lab., TN (United States); McKee, R.A. [Oak Ridge National Lab., TN (United States)

    1995-12-31

    Optical guided wave (OGW) devices, based on LiNbO{sub 3} or GaAs. are commercially available products with established markets and applications. While LiNbO{sub 3} presently dominates the commercial applications, there are several drivers for the development of improved electro-optic (EO) materials. If the appropriate crystal quality could be obtained for thin-film BaTiO{sub 3} supported on MgO for example, or for an integrated BaTiO{sub 3}/Mg0 structure on silicon or GaAs, then the optimum OGW device structure might be realized. We report on our results for the growth of optical quality, epitaxial BaTiO{sub 3} and SrTiO{sub 3} on single-crystal MgO substrates using source shuttering molecular beam epitaxy (MBE) techniques. We also discuss how these materials can be integrated onto silicon. Our MBE studies show that, for this important class of perovskite oxides, heteroepitaxy between the perovskites and alkaline earth oxides is dominated by interfacial electrostatics at the first atomic layers. We have been able to demonstrate that a layer-by-layer energy minimization associated with interfacial electrostatics leads to the growth of high quality thin films of these materials. We have fabricated waveguides from these materials, and the optical clarity and loss coefficients have been characterized and found to be comparable to in-diffused waveguide structures typically represented by Ti drifted LiNbO{sub 3}.

  7. Thin current sheets in collisionless plasma: Equilibrium structure, plasma instabilities, and particle acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Zelenyi, L. M.; Malova, H. V.; Artemyev, A. V.; Popov, V. Yu.; Petrukovich, A. A. [Russian Academy of Sciences, Space Research Institute (Russian Federation)

    2011-02-15

    The review is devoted to plasma structures with an extremely small transverse size, namely, thin current sheets that have been discovered and investigated by spacecraft observations in the Earth's magnetotail in the last few decades. The formation of current sheets is attributed to complicated dynamic processes occurring in a collisionless space plasma during geomagnetic perturbations and near the magnetic reconnection regions. The models that describe thin current structures in the Earth's magnetotail are reviewed. They are based on the assumption of the quasi-adiabatic ion dynamics in a relatively weak magnetic field of the magnetotail neutral sheet, where the ions can become unmagnetized. It is shown that the ion distribution can be represented as a function of the integrals of particle motion-the total energy and quasi-adiabatic invariant. Various modifications of the initial equilibrium are considered that are obtained with allowance for the currents of magnetized electrons, the contribution of oxygen ions, the asymmetry of plasma sources, and the effects related to the non-Maxwellian particle distributions. The theoretical results are compared with the observational data from the Cluster spacecraft mission. Various plasma instabilities developing in thin current sheets are investigated. The evolution of the tearing mode is analyzed, and the parameter range in which the mode can grow are determined. The paradox of complete stabilization of the tearing mode in current sheets with a nonzero normal magnetic field component is thereby resolved based on the quasi-adiabatic model. It is shown that, over a wide range of current sheet parameters and the propagation directions of large-scale unstable waves, various modified drift instabilities-kink and sausage modes-can develop in the system. Based on the concept of a turbulent electromagnetic field excited as a result of the development and saturation of unstable waves, a mechanism for charged particle

  8. Production of selective membranes using plasma deposited nanochanneled thin films

    Directory of Open Access Journals (Sweden)

    Rodrigo Amorim Motta Carvalho

    2006-12-01

    Full Text Available The hydrolization of thin films obtained by tetraethoxysilane plasma polymerization results in the formation of a nanochanneled silicone like structure that could be useful for the production of selective membranes. Therefore, the aim of this work is to test the permeation properties of hydrolyzed thin films. The films were tested for: 1 permeation of polar organic compounds and/or water in gaseous phase and 2 permeation of salt in liquid phase. The efficiency of permeation was tested using a quartz crystal microbalance (QCM technique in gas phase and conductimetric analysis (CA in liquid phase. The substrates used were: silicon for characterization of the deposited films, piezoelectric quartz crystals for tests of selective membranes and cellophane paper for tests of permeation. QCM analysis showed that the nanochannels allow the adsorption and/or permeation of polar organic compounds, such as acetone and 2-propanol, and water. CA showed that the films allow salt permeation after an inhibition time needed for hydrolysis of the organic radicals within the film. Due to their characteristics, the films can be used for grains protection against microorganism proliferation during storage without preventing germination.

  9. Transparent thin film polarizing and optical control systems

    Directory of Open Access Journals (Sweden)

    Nelson V. Tabiryan

    2011-06-01

    Full Text Available We show that a diffractive waveplate can be combined with a phase retardation film for fully converting light of arbitrary polarization state into a polarized light. Incorporating a photonic bandgap layer into a system of such polarizers that unify different polarization states in the input light into a single polarization state at its output, rather than absorbing or reflecting half of it, we developed and demonstrated a polarization-independent optical controller capable of switching between transmittive and reflective states. The transition between those states is smoothly controlled with low-voltage and low-power sources. Using versatile fabrication methods, this “universally polarizing optical controller” can be integrated into a thin package compatible with a variety of display, spatial light modulation, optical communication, imaging and other photonics systems.

  10. Optically thin hybrid cavity for terahertz photo-conductive detectors

    Science.gov (United States)

    Thompson, R. J.; Siday, T.; Glass, S.; Luk, T. S.; Reno, J. L.; Brener, I.; Mitrofanov, O.

    2017-01-01

    The efficiency of photoconductive (PC) devices, including terahertz detectors, is constrained by the bulk optical constants of PC materials. Here, we show that optical absorption in a PC layer can be modified substantially within a hybrid cavity containing nanoantennas and a Distributed Bragg Reflector. We find that a hybrid cavity, consisting of a GaAs PC layer of just 50 nm, can be used to absorb >75% of incident photons by trapping the light within the cavity. We provide an intuitive model, which describes the dependence of the optimum operation wavelength on the cavity thickness. We also find that the nanoantenna size is a critical parameter, small variations of which lead to both wavelength shifting and reduced absorption in the cavity, suggesting that impedance matching is key for achieving efficient absorption in the optically thin hybrid cavities.

  11. Simulations of electromagnetic emissions produced in a thin plasma by a continuously injected electron beam

    CERN Document Server

    Annenkov, V V; Volchok, E P

    2015-01-01

    In this paper, electromagnetic emissions produced in a thin beam-plasma system are studied using two-dimensional particle-in-cell simulations. For the first time, the problem of emission generation in such a system is considered in the realistic formulation allowing for the continuous injection of a relativistic electron beam through the plasma boundary. Specific attention is given to the thin plasma case in which the transverse plasma size is comparable to the typical wavelength of beam-driven oscillations. Such a case is often implemented in laboratory beam-plasma experiments and has a number of peculiarities. Emission from a thin plasma does not require intermediate generation of electromagnetic plasma eigenmodes, as in the infinite case, and is more similar to the regular antenna radiation. In this work, we determine how efficiently the fundamental and second harmonic emissions can be generated in previously modulated and initially homogeneous plasmas.

  12. Simulations of electromagnetic emissions produced in a thin plasma by a continuously injected electron beam

    Science.gov (United States)

    Annenkov, V. V.; Timofeev, I. V.; Volchok, E. P.

    2016-05-01

    In this paper, electromagnetic emissions produced in a thin beam-plasma system are studied using two-dimensional particle-in-cell simulations. For the first time, the problem of emission generation in such a system is considered in a realistic formulation allowing for the continuous injection of a relativistic electron beam through a plasma boundary. Specific attention is given to the thin plasma case in which the transverse plasma size is comparable to the typical wavelength of beam-driven oscillations. Such a case is often implemented in laboratory beam-plasma experiments and has a number of peculiarities. Emission from a thin plasma does not require intermediate generation of the electromagnetic plasma eigenmodes, as in an infinite case, and is more similar to the regular antenna radiation. In this work, we determine how efficiently the fundamental and the second harmonic emissions can be generated in previously modulated and initially homogeneous plasmas.

  13. The use of thin diamond films in fiber-optic low-coherence interferometers

    Science.gov (United States)

    Milewska, D.; Karpienko, K.

    2016-01-01

    In this paper we present the use of thin diamond films in fiber-optic low-coherence interferometers. Two kinds of diamond surfaces were used: undoped diamond film and boron- doped diamond film. They were deposited on glass plates as well as silicon layers. A conventionally used mirror was used as a reference layer. Diamond films were deposited using Microwave Plasma Enhanced Chemical Vapour Deposition (μPE CVD) system. Measurements were performed using two superluminescent diodes (SLD) with wavelengths of 1300 mm and 1550 mm. The optimal conditions for each layers were examined: the required wavelength of the light source and the length of Fabry-Perot interferometer cavity. Metrological parameters of Fabry-Perot interferometer with different mirrors were compared. The presented thin diamond films may be an interesting alternative to the commonly used reflective surfaces.

  14. Coating Thin Mirror Segments for Lightweight X-ray Optics

    Science.gov (United States)

    Chan, Kai-Wing; Sharpe, Marton V.; Zhang, William; Kolosc, Linette; Hong, Melinda; McClelland, Ryan; Hohl, Bruce R.; Saha, Timo; Mazzarellam, James

    2013-01-01

    Next generations lightweight, high resolution, high throughput optics for x-ray astronomy requires integration of very thin mirror segments into a lightweight telescope housing without distortion. Thin glass substrates with linear dimension of 200 mm and thickness as small as 0.4 mm can now be fabricated to a precision of a few arc-seconds for grazing incidence optics. Subsequent implementation requires a distortion-free deposition of metals such as iridium or platinum. These depositions, however, generally have high coating stresses that cause mirror distortion. In this paper, we discuss the coating stress on these thin glass mirrors and the effort to eliminate their induced distortion. It is shown that balancing the coating distortion either by coating films with tensile and compressive stresses, or on both sides of the mirrors is not sufficient. Heating the mirror in a moderately high temperature turns out to relax the coated films reasonably well to a precision of about a second of arc and therefore provide a practical solution to the coating problem.

  15. Plasma processing of niobium for the production of thin-film superconducting devices

    Energy Technology Data Exchange (ETDEWEB)

    Tugwell, A.J.; Hutson, D.; Pegrum, C.M.; Donaldson, G.B.

    1987-01-01

    Josephson junctions, which are regions of weak electrical connection between two superconductors, are the active elements of very sensitive thin-film magnetometers. Junctions are fabricated by growing barriers of native oxide on thin Nb films and depositing a layer of PbIn alloy on top. High sensitivity magnetometers require junctions of small area, and to achieve this, edge junctions are fabricated in which one dimension is defined by the thickness of the Nb and the other is set by the limit of optical lithography. An edge with a suitable angle is produced by reactive ion etching using 5 vol % O/sub 2/ in CF/sub 4/ in a parallel plate rf plasma etcher. Details of etch rates and edge profiles are given. The barrier is formed by a cleaning and oxidation process in an rf plasma at a pressure of 10/sup -6/ bar. Details of the design of a purpose built rf cathode and the run-to-run reproducibility of junction characteristics are given. Different oxidation times and bias voltages are necessary to produce a given oxide thickness on a sloping edge of Nb, as compared to a planar surface, and an explanation for this is proposed. Examples are described of magnetometers made using the above processes.

  16. Growth of nanocrystalline silicon carbide thin films by plasma enhanced chemical vapor deposition

    CERN Document Server

    Lee, S W; Moon, J Y; Ahn, S S; Kim, H Y; Shin, D H

    1999-01-01

    Nanocrystalline silicon carbide thin films have been deposited by plasma enhanced chemical vapor deposition (PECVD) using SiH sub 4 , CH sub 4 , and H sub 2 gases. The effects of gas mixing ratio (CH sub 4 /SiH sub 4), deposition temperature, and RF power on the film properties have been studied. The growth rate, refractive index, and the optical energy gap depends critically on the growth conditions. The dependence of the growth rate on the gas flow ratio is quite different from the results obtained for the growth using C sub 2 H sub 2 gas instead of CH sub 4. As the deposition temperature is increased from 300 .deg. C to 600 .deg. C, hydrogen and carbon content in the film decreases and as a result the optical gap decreases. At the deposition temperature of 600 .deg. C and RF power of 150 W, the film structure si nanocrystalline, As the result of the nanocrystallization the dark conductivity is greatly improved. The nanocrystalline silicon carbide thin films may be used for large area optoelectronic devices...

  17. Optical properties of Ge-As-Te thin films

    Science.gov (United States)

    Aly, K. A.; Abd Elnaeim, A. M.; Uosif, M. A. M.; Abdel-Rahim, O.

    2011-11-01

    Different compositions of GexAs10Te90-x (x=5, 10, 15, 20, and 25 at%) chalcogenide glasses were prepared by the usual melt quench technique. Amorphous GexAs10Te90-x thin films were deposited onto cleaned glass substrates using the thermal evaporation method. Transmission spectra, T(λ), of the films at normal incidence were measured in the wavelength range 400-2500 nm. A straightforward analysis proposed by Swanepoel based on the use of the maxima and minima of the interference fringes has been used to drive the film thickness, d, the complex index of refraction, n, and the extinction coefficient, k. It was found that, the addition of Ge content at the expense of Te atoms shifts the optical band gap to the short wavelength side (blue shift of the optical band gap) while the refractive index are found to decreases. The obtained results of the refractive index were discussed in terms of the electronic polarizability and the single-oscillator Wemple and DiDomenico model (WDD). The optical absorption is due to the allowed non-direct optical transitions. The observed increase in the optical band gap with the increase in Ge content was discussed in terms of the width of the tail states in the gap and the covalent bond approach.

  18. Defect enhanced optic and electro-optic properties of lead zirconate titanate thin films

    Directory of Open Access Journals (Sweden)

    M. M. Zhu

    2011-12-01

    Full Text Available Pb(Zr1-xTixO3 (PZT thin films near phase morphotropic phase boundary were deposited on (Pb0.86La0.14TiO3-coated glass by radio frequency sputtering. A retrieved analysis shows that the lattice parameters of the as-grown PZT thin films were similar to that of monoclinic PZT structure. Moreover, the PZT thin films possessed refractive index as high as 2.504 in TE model and 2.431 in TM model. The as-grown PZT thin film had one strong absorption peak at 632.6 nm, which attributed to lead deficiency by quantitative XPS analysis. From the attractive properties achieved, electro-optic and photovoltaic characteristic of the films were carried out.

  19. Solution precursor plasma deposition of nanostructured CdS thin films

    Energy Technology Data Exchange (ETDEWEB)

    Tummala, Raghavender [Department of Mechanical Engineering, University of Michigan, Dearborn, MI 48128 (United States); Guduru, Ramesh K., E-mail: rkguduru@umich.edu [Department of Mechanical Engineering, University of Michigan, Dearborn, MI 48128 (United States); Mohanty, Pravansu S. [Department of Mechanical Engineering, University of Michigan, Dearborn, MI 48128 (United States)

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer Inexpensive process with capability to produce large scale nanostructured coatings. Black-Right-Pointing-Pointer Technique can be employed to spray the coatings on any kind of substrates including polymers. Black-Right-Pointing-Pointer The CdS coatings developed have good electrical conductivity and optical properties. Black-Right-Pointing-Pointer Coatings possess large amount of particulate boundaries and nanostructured grains. -- Abstract: Cadmium sulfide (CdS) films are used in solar cells, sensors and microelectronics. A variety of techniques, such as vapor based techniques, wet chemical methods and spray pyrolysis are frequently employed to develop adherent CdS films. In the present study, rapid deposition of CdS thin films via plasma spray route using a solution precursor was investigated, for the first time. Solution precursor comprising cadmium chloride, thiourea and distilled water was fed into a DC plasma jet via an axial atomizer to create ultrafine droplets for instantaneous and accelerated thermal decomposition in the plasma plume. The resulting molten/semi-molten ultrafine/nanoparticles of CdS eventually propel toward the substrate to form continuous CdS films. The chemistry of the solution precursor was found to be critical in plasma pyrolysis to control the stoichiometry and composition of the films. X-ray diffraction studies confirmed hexagonal {alpha}-CdS structure. Surface morphology and microstructures were investigated to compare with other synthesis techniques in terms of process mechanism and structural features. Transmission electron microscopy studies revealed nanostructures in the atomized particulates. Optical measurements indicated a decreasing transmittance in the visible light with increasing the film thickness and band gap was calculated to be {approx}2.5 eV. The electrical resistivity of the films (0.243 {+-} 0.188 Multiplication-Sign 10{sup 5} {Omega} cm) was comparable with the literature

  20. Magneto-optic properties and optical parameter of thin MnCo films

    Directory of Open Access Journals (Sweden)

    E Attaran Kakhki

    2009-09-01

    Full Text Available Having precise hysterics loop of thin ferroelectric and ferromagnetic layers for optical switching and optical storages are important. A hysterieses loop can be achieved from a phenomenon call the magneto-optic effect. The magneto-optic effect is the rotation of a linear polarized electromagnetic wave propagated through a ferromagnetic medium. When light is transmitted through a layer of magnetic material the result is called the Faraday effects and in the reflection mode Kerr effect. In the present work we prepared a thin layer of MnxCo3-xO4 (0≤ x ≤ 1 and a binary form of MnO/Co3O4 by the spray pyrolysis method. The films have been characterized by a special set up of magneto-optic hysterics loop plotter containing a polarized He- Ne laser beam and a special electronic circuit. Faraday rotation were measured for these films by hysterics loop plotter and their optical properties were also obtained by spatial software designed for this purpose according to Swane Poel theoretical method. The measurements show that the samples at diluted Mn study has are ferromagnetic and the magneto-optic rotation show a good enhance respect to the single Co layers. Also, the study has shown that the MnCo oxide layer have two different energy gaps and by increasing of Mn this energy decreases and fall to 0.13 eV.

  1. Optically Thin Liquid Water Clouds: Their Importance and Our Challenge

    Science.gov (United States)

    Turner, D. D.; Vogelmann, A. M.; Austin, R. T.; Barnard, J. C.; Cady-Pereira, K.; Chiu, J. C.; Clough, S. A.; Flynn, C.; Khaiyer, M. M.; Liljegren, J.; Johnson, K.; Lin, B.; Long, C.; Marshak, A.; Matrosov, S. Y.; McFarlane, S. A.; Miller, M.; Min, Q.; Minnis, P.; O'Hirok, W.; Wang, Z.; Wiscombe, W.

    2006-01-01

    Many of the clouds important to the Earth's energy balance, from the tropics to the Arctic, are optically thin and contain liquid water. Longwave and shortwave radiative fluxes are very sensitive to small perturbations of the cloud liquid water path (LWP) when the liquid water path is small (i.e., challenging to retrieve their microphysical properties accurately. We describe a retrieval algorithm intercomparison that was conducted to evaluate the issues involved. The intercomparison included eighteen different algorithms to evaluate their retrieved LWP, optical depth, and effective radii. Surprisingly, evaluation of the simplest case, a single-layer overcast cloud, revealed that huge discrepancies exist among the various techniques, even among different algorithms that are in the same general classification. This suggests that, despite considerable advances that have occurred in the field, much more work must be done, and we discuss potential avenues for future work.

  2. Choking of optically thin spherical accreation by dissipative heating

    Energy Technology Data Exchange (ETDEWEB)

    Scharlemann, E.T.

    1981-05-15

    Dissipative heating can be sufficient to reduce the Mach number of supersonic spherical accretion to unity in the optically thin part of the flow: at a radius of order 10/sup 2/--10/sup 3/ Schwarzchild radii. If the flow at a larger radius is forced to be supersonic and cold, by some cooling process like collisional excitation of line radiation, the flow cannot be time-independent. The critical accretion rates below which accretion flows either are forced to be time dependent, or become optically thick before the minimum in the Mach number is reached, are determined. The implication for the time variability of quasars and active galactic nuclei is briefly discussed.

  3. Study of Linear and Non-Linear Optical Parameters of Zinc Selenide Thin Film

    OpenAIRE

    Desai, H. N.; J. M. Dhimmar

    2015-01-01

    Thin film of Zinc Selenide (ZnSe) was deposited onto transparent glass substrate by thermal evaporation technique. ZnSe thin film was characterized by UV-Visible spectrophotometer within the wavelength range of 310 nm-1080 nm. The Linear optical parameters (linear optical absorption, extinction coefficient, refractive index and complex dielectric constant) of ZnSe thin film were analyzed from absorption spectra. The optical band gap and Urbach energy were obtained by Tauc’s equati...

  4. Preparation of nanostructured Bi-modified TiO2 thin films by crossed-beam laser ablation plasmas

    Science.gov (United States)

    Escobar-Alarcon, L.; Solís-Casados, D. A.; González-Zavala, F.; Romero, S.; Fernandez, M.; Haro-Poniatowski, E.

    2017-01-01

    The preparation and characterization of titanium dioxide thin films modified with different amounts of bismuth using a two laser ablation plasmas configuration is reported. The plasmas were produced ablating simultaneously two different targets, one of bismuth and other of titanium dioxide, using a Nd:YAG laser with emission in the fundamental line. The elemental composition, together with the vibrational and optical properties of the deposited films were investigated as a function of the parameters of the bismuth plasma. The composition of the thin films was determined from measurements of X-ray photoelectron spectroscopy (XPS) as well as by Rutherford backscattering spectroscopy (RBS). The structural modification of the deposited material, due to the incorporation of Bi, was characterized by Raman spectroscopy. The optical properties were determined from UV-Vis spectroscopy measurements. It is found that bismuth incorporation has an important effect on the optical properties of TiO2 narrowing the band gap from 3.2 to 2.5 eV.

  5. Atmospheric pressure plasma jet-synthesized electrochromic organomolybdenum oxide thin films for flexible electrochromic devices

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yung-Sen, E-mail: yslin@fcu.edu.tw; Tsai, Tsung-Hsien; Tien, Shih-Wei

    2013-02-01

    An investigation is conducted into fast synthesis of electrochromic organomolybdenum oxide (MoO{sub x}C{sub y}) thin films onto 40 Ω/□ flexible polyethylene terephthalate/indium tin oxide substrates via atmospheric pressure plasma jet. A precursor [molybdenum carbonyl, Mo(CO){sub 6}] vapor, carried by argon gas, is injected into air plasma torch to synthesize MoO{sub x}C{sub y} films for offering extraordinary electrochromic performance. Only low driving voltages from − 1 V to 1 V are needed to offer reversible Li{sup +} ion intercalation and deintercalation in a 1 M LiClO{sub 4}-propylene carbonate electrolyte. Light modulation with transmittance variation of up to 61%, optical density change of 0.54 and coloration efficiency of 37.5 cm{sup 2}/C at a wavelength of 550 nm after 200 cycles of cyclic voltammetry switching measurements is achieved. - Highlights: ► Fast deposition of MoO{sub x}C{sub y} film by an atmospheric pressure plasma jet ► Organic–inorganic hybrid MoO{sub x}C{sub y} films synthesized ► Flexible and electrochromic MoO{sub x}C{sub y} films produced.

  6. Studies on thin film materials on acrylics for optical applications

    Indian Academy of Sciences (India)

    K Narasimha Rao

    2003-02-01

    Deposition of durable thin film coatings by vacuum evaporation on acrylic substrates for optical applications is a challenging job. Films crack upon deposition due to internal stresses and leads to performance degradation. In this investigation, we report the preparation and characterization of single and multi-layer films of TiO2, CeO2, Substance2 (E Merck, Germany), Al2O3, SiO2 and MgF2 by electron beam evaporation on both glass and PMMA substrates. Optical micrographs taken on single layer films deposited on PMMA substrates did not reveal any cracks. Cracks in films were observed on PMMA substrates when the substrate temperature exceeded 80°C. Antireflection coatings of 3 and 4 layers have been deposited and characterized. Antireflection coatings made on PMMA substrate using Substance2 (H2) and SiO2 combination showed very fine cracks when observed under microscope. Optical performance of the coatings has been explained with the help of optical micrographs.

  7. Hard X-ray quantum optics in thin films nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Haber, Johann Friedrich Albert

    2017-05-15

    This thesis describes quantum optical experiments with X-rays with the aim of reaching the strong-coupling regime of light and matter. We make use of the interaction which arises between resonant matter and X-rays in specially designed thin-film nanostructures which form X-ray cavities. Here, the resonant matter are Tantalum atoms and the Iron isotope {sup 57}Fe. Both limit the number of modes available to the resonant atoms for interaction, and enhances the interaction strength. Thus we have managed to observe a number of phenomena well-known in quantum optics, which are the building blocks for sophisticated applications in e.g. metrology. Among these are the strong coupling of light and matter and the concurrent exchange of virtual photons, often called Rabi oscillations. Furthermore we have designed and tested a type of cavity hitherto unused in X-ray optics. Finally, we develop a new method for synchrotron Moessbauer spectroscopy, which not only promises to yield high-resolution spectra, but also enables the retrieval of the phase of the scattered light. The results open new avenues for quantum optical experiments with X-rays, particularly with regards to the ongoing development of high-brilliance X-ray free-electron lasers.

  8. Optics effects of splitting dipole magnets into several thin lenses

    CERN Document Server

    Leunissen, L H A

    1998-01-01

    The evaluation of the dynamic aperture and the calculation of non linear optics parameters have been made so far with the simplest model of dipole, i.e. a single thin lens positioned at the centre of each thick dipole. It was shown recently that the non-linear chromaticity decreases significantly when the thick lens is represented by two thin lenses or more instead of one. In this note the study is extended to amplitude detuning and dynamic aperture. Unlike the observation reported on non-linear chromatic detuning we find no significant changes for the dynamic aperture and amplitude d etuning when the dipole magnets are split in more than one thin lens. Furthermore, non-uniform azimuthal distribution of the multipoles inside the dipole is shown not to change the above-mentio ned results. In both cases, the influence of the beta-funtions is expected to give large effect for a given dipole. However, integrated over one cell this effect is shown to compensate to a large extent. erture reported on non-linear chro...

  9. Optically Transparent Thin-Film Electrode Chip for Spectroelectrochemical Sensing

    Energy Technology Data Exchange (ETDEWEB)

    Branch, Shirmir D.; Lines, Amanda M.; Lynch, John A.; Bello, Job M.; Heineman, William R.; Bryan, Samuel A.

    2017-07-03

    The electrochemical and spectroelectrochemical applications of an optically transparent thin film electrode chip are investigated. The working electrode is composed of indium tin oxide (ITO); the counter and quasi-reference electrodes are composed of platinum. The stability of the platinum quasi-reference electrode is modified by coating it with a planar, solid state Ag/AgCl layer. The Ag/AgCl reference is characterized with scanning electron microscopy and energy-dispersive X-ray spectroscopy. Open circuit potential measurements indicate that the potential of the planar Ag/AgCl electrode varies a maximum of 20 mV over four days. Cyclic voltammetry measurements show that the electrode chip is comparable to a standard electrochemical cell. Randles-Sevcik analysis of 10 mM K3[Fe(CN)6] in 0.1 M KCl using the electrode chip shows a diffusion coefficient of 1.59 × 10-6 cm2/s, in comparison to the standard electrochemical cell value of 2.38 × 10-6 cm2/s. By using the electrode chip in an optically transparent thin layer electrode (OTTLE), the spectroelectrochemical modulation of [Ru(bpy)3]2+ florescence was demonstrated, achieving a detection limit of 36 nM.

  10. Electron beam manipulation, injection and acceleration in plasma wakefield accelerators by optically generated plasma density spikes

    Energy Technology Data Exchange (ETDEWEB)

    Wittig, Georg; Karger, Oliver S.; Knetsch, Alexander [Institute of Experimental Physics, University of Hamburg, 22761 Hamburg (Germany); Xi, Yunfeng; Deng, Aihua; Rosenzweig, James B. [Particle Beam Physics Laboratory, UCLA, Los Angeles, CA 90095 (United States); Bruhwiler, David L. [RadiaSoft LLC, Boulder, CO 80304 (United States); RadiaBeam Technologies LLC (United States); Smith, Jonathan [Tech-X UK Ltd, Daresbury, Cheshire WA4 4FS (United Kingdom); Sheng, Zheng-Ming; Jaroszynski, Dino A.; Manahan, Grace G. [Physics Department, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Hidding, Bernhard [Institute of Experimental Physics, University of Hamburg, 22761 Hamburg (Germany); Physics Department, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom)

    2016-09-01

    We discuss considerations regarding a novel and robust scheme for optically triggered electron bunch generation in plasma wakefield accelerators [1]. In this technique, a transversely propagating focused laser pulse ignites a quasi-stationary plasma column before the arrival of the plasma wake. This localized plasma density enhancement or opticalplasma torch” distorts the blowout during the arrival of the electron drive bunch and modifies the electron trajectories, resulting in controlled injection. By changing the gas density, and the laser pulse parameters such as beam waist and intensity, and by moving the focal point of the laser pulse, the shape of the plasma torch, and therefore the generated trailing beam, can be tuned easily. The proposed method is much more flexible and faster in generating gas density transitions when compared to hydrodynamics-based methods, and it accommodates experimentalists needs as it is a purely optical process and straightforward to implement.

  11. Electron beam manipulation, injection and acceleration in plasma wakefield accelerators by optically generated plasma density spikes

    Science.gov (United States)

    Wittig, Georg; Karger, Oliver S.; Knetsch, Alexander; Xi, Yunfeng; Deng, Aihua; Rosenzweig, James B.; Bruhwiler, David L.; Smith, Jonathan; Sheng, Zheng-Ming; Jaroszynski, Dino A.; Manahan, Grace G.; Hidding, Bernhard

    2016-09-01

    We discuss considerations regarding a novel and robust scheme for optically triggered electron bunch generation in plasma wakefield accelerators [1]. In this technique, a transversely propagating focused laser pulse ignites a quasi-stationary plasma column before the arrival of the plasma wake. This localized plasma density enhancement or optical "plasma torch" distorts the blowout during the arrival of the electron drive bunch and modifies the electron trajectories, resulting in controlled injection. By changing the gas density, and the laser pulse parameters such as beam waist and intensity, and by moving the focal point of the laser pulse, the shape of the plasma torch, and therefore the generated trailing beam, can be tuned easily. The proposed method is much more flexible and faster in generating gas density transitions when compared to hydrodynamics-based methods, and it accommodates experimentalists needs as it is a purely optical process and straightforward to implement.

  12. Laser Plasmas : Optical guiding of laser beam in nonuniform plasma

    Indian Academy of Sciences (India)

    Tarsem Singh Gill

    2000-11-01

    A plasma channel produced by a short ionising laser pulse is axially nonuniform resulting from the self-defocusing. Through such preformed plasma channel, when a delayed pulse propagates, the phenomena of diffraction, refraction and self-phase modulation come into play. We have solved the nonlinear parabolic partial differential equation governing the propagation characteristics for an approximate analytical solution using variational approach. Results are compared with the theoretical model of Liu and Tripathi (Phys. Plasmas 1, 3100 (1994)) based on paraxial ray approximation. Particular emphasis is on both beam width and longitudinal phase delay which are crucial to many applications.

  13. Propagation of Surface Wave Along a Thin Plasma Column and Its Radiation Pattern

    Institute of Scientific and Technical Information of China (English)

    WANG Zhijiang; ZHAO Guowei; XU Yuemin; LIANG Zhiwei; XU Jie

    2007-01-01

    Propagation of the surface waves along a two-dimensional plasma column and the far-field radiation patterns are studied in thin column approximation. Wave phase and attenuation coefficients are calculated for various plasma parameters. The radiation patterns are shown. Results show that the radiation patterns are controllable by flexibly changing the plasma length and other parameters in comparison to the metal monopole antenna. It is meaningful and instructional for the optimization of the plasma antenna design.

  14. Influence of bias voltage on structural and optical properties of TiN{sub x} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Omveer, E-mail: poonia.omveer@gmail.com [Centre for Energy Studies, Indian Institute of Technology Delhi, New Delhi – 110016 (India); Dahiya, Raj P. [Centre for Energy Studies, Indian Institute of Technology Delhi, New Delhi – 110016 (India); Deenbandhu Chhotu Ram University of Science and Technology, Murthal – 131039 (India); Malik, Hitendra K.; Kumar, Parmod [Department of Physics, Indian Institute of Technology Delhi, New Delhi – 110016 (India)

    2015-08-28

    In the present work, Ti thin films were deposited on Si substrate using DC sputtering technique. Indigenous hot cathode arc discharge plasma system was used for nitriding over these samples, where the plasma parameters and work piece can be controlled independently. A mixture of H{sub 2} and N{sub 2} gases (in the ratio of 80:20) was supplied into the plasma chamber. The effect of bias voltage on the crystal structure, morphology and optical properties was investigated by employing various physical techniques such as X-ray Diffraction, Atomic Force Microscopy and UV-Vis spectrometry. It was found that bias voltage affects largely the crystal structure and band gap which in turn is responsible for the modifications in optical properties of the deposited films.

  15. High-efficiency fast scintillators for "optical" soft x-ray arrays for laboratory plasma diagnostics.

    Science.gov (United States)

    Delgado-Aparicio, L F; Stutman, D; Tritz, K; Vero, R; Finkenthal, M; Suliman, G; Kaita, R; Majeski, R; Stratton, B; Roquemore, L; Tarrio, C

    2007-08-20

    Scintillator-based "optical" soft x-ray (OSXR) arrays have been investigated as a replacement for the conventional silicon (Si)-based diode arrays used for imaging, tomographic reconstruction, magnetohydrodynamics, transport, and turbulence studies in magnetically confined fusion plasma research. An experimental survey among several scintillator candidates was performed, measuring the relative and absolute conversion efficiencies of soft x rays to visible light. Further investigations took into account glass and fiber-optic face-plates (FOPs) as substrates, and a thin aluminum foil (150 nm) to reflect the visible light emitted by the scintillator back to the optical detector. Columnar (crystal growth) thallium-doped cesium iodide (CsI:Tl) deposited on an FOP, was found to be the best candidate for the previously mentioned plasma diagnostics. Its luminescence decay time of the order of approximately 1-10 micros is thus suitable for the 10 micros time resolution required for the development of scintillator-based SXR plasma diagnostics. A prototype eight channel OSXR array using CsI:Tl was designed, built, and compared to an absolute extreme ultraviolet diode counterpart: its operation on the National Spherical Torus Experiment showed a lower level of induced noise relative to the Si-based diode arrays, especially during neutral beam injection heated plasma discharges. The OSXR concept can also be implemented in less harsh environments for basic spectroscopic laboratory plasma diagnostics.

  16. Wettability, optical properties and molecular structure of plasma polymerized diethylene glycol dimethyl ether

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, T C A M; Algatti, M A; Mota, R P; Honda, R Y; Kayama, M E; Kostov, K G; Fernandes, R S [FEG-DFQ-UNESP, Av. Ariberto Pereira da Cunha 333, 12516-410 - Guaratingueta, SP (Brazil); Cruz, N C; Rangel, E C, E-mail: algatti@feg.unesp.b [UNESP, Avenida Tres de Marco, 511, 18087-180 Sorocaba, SP (Brazil)

    2009-05-01

    Modern industry has frequently employed ethylene glycol ethers as monomers in plasma polymerization process to produce different types of coatings. In this work we used a stainless steel plasma reactor to grow thin polymeric films from low pressure RF excited plasma of diethylene glycol dimethyl ether. Plasmas were generated at 5W RF power in the range of 16 Pa to 60 Pa. The molecular structure of plasma polymerized films and their optical properties were analyzed by Fourier Transform Infrared Spectroscopy (FTIR) and Ultraviolet-Visible Spectroscopy, respectively. The IR spectra show C-H stretching at 3000-2900 cm{sup -1}, C=O stretching at 1730-1650 cm{sup -1}, C-H bending at 1440-1380 cm{sup -1}, C-O and C-O-C stretching at 1200-1000 cm{sup -1}. The refraction index was around 1.5 and the optical gap calculated from absorption coefficient presented value near 3.8 eV. Water contact angle of the films ranged from 40 deg. to 35 deg. with corresponding surface energy from 66 to 73x10{sup -7} J. Because of its favorable optical and hydrophilic characteristics these films can be used in ophthalmic industries as glass lenses coatings.

  17. Electro-optic probe measurements of electric fields in plasmas

    Science.gov (United States)

    Nishiura, M.; Yoshida, Z.; Mushiake, T.; Kawazura, Y.; Osawa, R.; Fujinami, K.; Yano, Y.; Saitoh, H.; Yamasaki, M.; Kashyap, A.; Takahashi, N.; Nakatsuka, M.; Fukuyama, A.

    2017-02-01

    The direct measurements of high-frequency electric fields in a plasma bring about significant advances in the physics and engineering of various waves. We have developed an electro-optic sensor system based on the Pockels effect. Since the signal is transmitted through an optical fiber, the system has high tolerance for electromagnetic noises. To demonstrate its applicability to plasma experiments, we report the first result of measurement of the ion-cyclotron wave excited in the RT-1 magnetosphere device. This study compares the results of experimental field measurements with simulation results of electric fields in plasmas.

  18. Feasibility of Ultra-Thin Fiber-Optic Dosimeters for Radiotherapy Dosimetry

    Directory of Open Access Journals (Sweden)

    Bongsoo Lee

    2015-11-01

    Full Text Available In this study, prototype ultra-thin fiber-optic dosimeters were fabricated using organic scintillators, wavelength shifting fibers, and plastic optical fibers. The sensor probes of the ultra-thin fiber-optic dosimeters consisted of very thin organic scintillators with thicknesses of 100, 150 and 200 μm. These types of sensors cannot only be used to measure skin or surface doses but also provide depth dose measurements with high spatial resolution. With the ultra-thin fiber-optic dosimeters, surface doses for gamma rays generated from a Co-60 therapy machine were measured. Additionally, percentage depth doses in the build-up regions were obtained by using the ultra-thin fiber-optic dosimeters, and the results were compared with those of external beam therapy films and a conventional fiber-optic dosimeter.

  19. Optical properties of CeO2 thin films

    Indian Academy of Sciences (India)

    S Debnath; M R Islam; M S R Khan

    2007-08-01

    Cerium oxide (CeO2) thin films have been prepared by electron beam evaporation technique onto glass substrate at a pressure of about 6 × 10-6 Torr. The thickness of CeO2 films ranges from 140–180 nm. The optical properties of cerium oxide films are studied in the wavelength range of 200–850 nm. The film is highly transparent in the visible region. It is also observed that the film has low reflectance in the ultra-violet region. The optical band gap of the film is determined and is found to decrease with the increase of film thickness. The values of absorption coefficient, extinction coefficient, refractive index, dielectric constant, phase angle and loss angle have been calculated from the optical measurements. The X-ray diffraction of the film showed that the film is crystalline in nature. The crystallite size of CeO2 films have been evaluated and found to be small. The experimental -values of the film agreed closely with the standard values.

  20. A thin column of dense plasma for space-charge neutralization of intense ion beams

    Science.gov (United States)

    Roy, P. K.; Seidl, P. A.; Anders, A.; Barnard, J. J.; Bieniosek, F. M.; Friedman, A.; Gilson, E. P.; Greenway, W.; Sefkow, A. B.; Jung, J. Y.; Leitner, M.; Lidia, S. M.; Logan, B. G.; Waldron, W. L.; Welch, D. R.

    2008-11-01

    Typical ion driven warm dense matter experiment requires a plasma density of 10^14/cm^3 to meet the challenge of np>nb, where np, and nb are the number densities of plasma and beam, respectively. Plasma electrons neutralize the space charge of an ion beam to allow a small spot of about 1-mm radius. In order to provide np>nb for initial warm, dense matter experiments, four cathodic arc plasma sources have been fabricated, and the aluminum plasma is focused in a focusing solenoid (8T field). A plasma probe with 37 collectors was developed to measure the radial plasma profile inside the solenoid. Results show that the plasma forms a thin column of diameter ˜7mm along the solenoid axis. The magnetic mirror effect, plasma condensation, and the deformation of the magnetic field due to eddy currents are under investigation. Data on plasma parameters and ion beam neutralization will be presented.

  1. Optical properties of hydroxyethyl cellulose film treated with nitrogen plasma

    Science.gov (United States)

    Mahmoud, K. H.

    2016-03-01

    Hydroxyethyl cellulose (HEC) film has been prepared by casting technique. The prepared sample has been treated with nitrogen plasma at different exposure times. The optical absorption was recorded at room temperature in the wavelength range of 200-800 nm. Absorbance fitting procedure curves revealed a direct allowed transition with optical band gap, Eopt, of 4.9 eV for pristine film, and this value decreases to 4.30 eV for 20 min plasma treatment time. The band tail values (Ee) were found to be increased under plasma time treatment from 1.74 eV in case of the pristine film to 2.20 eV for 20 min. The dispersion of refractive index and complex dielectric constants under plasma treatment was also studied. Variation of color parameters under effect of the plasma treatment is analyzed in the framework of CIE L*U*V* color space.

  2. Immobilization and controlled release of drug using plasma polymerized thin film

    Energy Technology Data Exchange (ETDEWEB)

    Myung, Sung-Woon [Department of Dental Materials, School of Dentistry, MRC Center, Chosun University, 309 Pilmun-daero, Dong-gu, Gwangju (Korea, Republic of); Jung, Sang-Chul [Department of Environmental Engineering, Sunchon National University, Sunchon 540-742 (Korea, Republic of); Kim, Byung-Hoon, E-mail: kim5055@chosun.ac.kr [Department of Dental Materials, School of Dentistry, MRC Center, Chosun University, 309 Pilmun-daero, Dong-gu, Gwangju (Korea, Republic of)

    2015-06-01

    In this study, plasma polymerization of acrylic acid was employed to immobilize drug and control its release. Doxorubicin (DOX) was immobilized covalently on the glass surface deposited with plasma polymerized acrylic acid (PPAAc) thin film containing the carboxylic group. At first, the PPAAc thin film was coated on a glass surface at a pressure of 1.33 Pa and radio frequency (RF) discharge power of 20 W for 10 min. DOX was immobilized on the PPAAc deposition in a two environment of phosphate buffer saline (PBS) and dimethyl sulfoxide (DMSO) solutions. The DOX immobilized surface was characterized by scanning electron microscope, atomic force microscope and attenuated total reflection Fourier transform infrared spectroscopy. The DOX molecules were more immobilized in PBS than DMSO solution. The different immobilization and release profiles of DOX result from the solubility of hydrophobic DOX in aqueous and organic solutions. Second, in order to control the release of the drug, PPAAc thin film was covered over DOX dispersed layer. Different thicknesses and cross-linked PPAAc thin films by adjusting deposition time and RF discharge power were covered on the DOX layer dispersed. PPAAc thin film coated DOX layer reduced the release rate of DOX. The thickness control of plasma deposition allows controlling the release rate of drug. - Highlights: • Doxorubicin was immobilized on the surface of plasma polymerized acrylic acid thin film. • Release profile of doxorubicin was affected by aqueous and organic solutions. • Plasma polymerized acrylic acid thin film can be used to achieve controlled release.

  3. Optical study of thin-film photovoltaic cells with apparent optical path length

    Science.gov (United States)

    Cho, Changsoon; Jeong, Seonju; Lee, Jung-Yong

    2016-09-01

    Extending the insufficient optical path length (OPL) in thin-film photovoltaic cells (PVs) is the key to achieving a high power conversion efficiency (PCE) in devices. Here, we introduce the apparent OPL (AOPL) as a figure of merit for light absorbing capability in thin-film PVs. The optical characteristics such as the structural effects and angular responses in thin-film PVs were analyzed in terms of the AOPL. Although the Lambertian scattering surface yields a broadband absorption enhancement in thin-film PVs, the enhancement is not as effective as in thick-film PVs. On the other hand, nanophotonic schemes are introduced as an approach to increasing the single-pass AOPL by inducing surface plasmon resonance. The scheme using periodic metal gratings is proved to increase the AOPL in a narrow wavelength range and specific polarization, overcoming the Yablonovitch limit. The AOPL calculation can be also adopted in the experimental analysis and a maximum AOPL of 4.15d (where d is the active layer thickness) is exhibited in the absorption band edge region of PTB7:PC70BM-based polymer PVs.

  4. Towards Enhanced Performance Thin-film Composite Membranes via Surface Plasma Modification

    OpenAIRE

    Rackel Reis; Dumée, Ludovic F.; Tardy, Blaise L.; Raymond Dagastine; John D. Orbell; Jürg A. Schutz; Duke, Mikel C.

    2016-01-01

    Advancing the design of thin-film composite membrane surfaces is one of the most promising pathways to deal with treating varying water qualities and increase their long-term stability and permeability. Although plasma technologies have been explored for surface modification of bulk micro and ultrafiltration membrane materials, the modification of thin film composite membranes is yet to be systematically investigated. Here, the performance of commercial thin-film composite desalination membra...

  5. Optical constants and nonlinear calculations of fluorescein/FTO thin film optical system

    Science.gov (United States)

    Zahran, H. Y.; Iqbal, Javed; Yahia, I. S.

    2016-11-01

    The organic thin films of fluorescein dye were deposited on fluorine-doped tin oxide glass substrate by using low-cost spin coating technique. The surface of the deposited film was characterized by using AFM and X-ray diffraction spectroscopy, which shows that the film is uniform and amorphous. The spectrophotometric study was carried out at the wavelength range of 300-2500 nm. The spectral dependences of the linear refractive index and absorption index were found to decrease as the wavelength was increased. Tauc's plot study revealed that the film shows the direct transition and energy band gap values were found 1.75 eV and 3.55 eV for the thin film and the substrate, respectively. Optical constants were found nearly the same in the higher energy domain (1.0-4.5 eV). Spectroscopic method was employed to study the nonlinear optical susceptibility χ (3). The deposited thin film is a promising optical system for new generation of optoelectronics.

  6. Electromagnetic and optical characteristics of Nb5+-doped double-crossover and salmon DNA thin films

    Science.gov (United States)

    Babu Mitta, Sekhar; Reddy Dugasani, Sreekantha; Jung, Soon-Gil; Vellampatti, Srivithya; Park, Tuson; Park, Sung Ha

    2017-10-01

    We report the fabrication and physical characteristics of niobium ion (Nb5+)-doped double-crossover DNA (DX-DNA) and salmon DNA (SDNA) thin films. Different concentrations of Nb5+ ([Nb5+]) are coordinated into the DNA molecules, and the thin films are fabricated via substrate-assisted growth (DX-DNA) and drop-casting (SDNA) on oxygen plasma treated substrates. We conducted atomic force microscopy to estimate the optimum concentration of Nb5+ ([Nb5+]O = 0.08 mM) in Nb5+-doped DX-DNA thin films, up to which the DX-DNA lattices maintain their structures without deformation. X-ray photoelectron spectroscopy (XPS) was performed to probe the chemical nature of the intercalated Nb5+ in the SDNA thin films. The change in peak intensities and the shift in binding energy were witnessed in XPS spectra to explicate the binding and charge transfer mechanisms between Nb5+ and SDNA molecules. UV-visible, Raman, and photoluminescence (PL) spectra were measured to determine the optical properties and thus investigate the binding modes, Nb5+ coordination sites in Nb5+-doped SDNA thin films, and energy transfer mechanisms, respectively. As [Nb5+] increases, the absorbance peak intensities monotonically increase until ∼[Nb5+]O and then decrease. However, from the Raman measurements, the peak intensities gradually decrease with an increase in [Nb5+] to reveal the binding mechanism and binding sites of metal ions in the SDNA molecules. From the PL, we observe the emission intensities to reduce them at up to ∼[Nb5+]O and then increase after that, expecting the energy transfer between the Nb5+ and SDNA molecules. The current–voltage measurement shows a significant increase in the current observed as [Nb5+] increases in the SDNA thin films when compared to that of pristine SDNA thin films. Finally, we investigate the temperature dependent magnetization in which the Nb5+-doped SDNA thin films reveal weak ferromagnetism due to the existence of tiny magnetic dipoles in the Nb5+-doped

  7. Growth and optical characteristics of high-quality ZnO thin films on graphene layers

    Directory of Open Access Journals (Sweden)

    Suk In Park

    2015-01-01

    Full Text Available We report the growth of high-quality, smooth, and flat ZnO thin films on graphene layers and their photoluminescence (PL characteristics. For the growth of high-quality ZnO thin films on graphene layers, ZnO nanowalls were grown using metal-organic vapor-phase epitaxy on oxygen-plasma treated graphene layers as an intermediate layer. PL measurements were conducted at low temperatures to examine strong near-band-edge emission peaks. The full-width-at-half-maximum value of the dominant PL emission peak was as narrow as 4 meV at T = 11 K, comparable to that of the best-quality films reported previously. Furthermore, the stimulated emission of ZnO thin films on the graphene layers was observed at the low excitation energy of 180 kW/cm2 at room temperature. Their structural and optical characteristics were investigated using X-ray diffraction, transmission electron microscopy, and PL spectroscopy.

  8. Plasma-induced TCO texture of ZnO:Ga back contacts on silicon thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Kuang-Chieh; Houng, Mau-Phon [Institute of Microelectronics, Department of Electrical Engineering, National Cheng Kung University, No. 1, Dasyue Rd., East District, Tainan City 701 (China); Wang, Jen-Hung; Lu, Chun-hsiung; Tsai, Fu-Ji; Yeh, Chih-Hung [NexPower Technology Corporation, Taichung County 421 (China)

    2011-02-15

    This paper considers texturing of ZnO:Ga (GZO) films used as back contacts in amorphous silicon (a-Si) thin film solar cells. GZO thin films are first prepared by conventional methods. The as-deposited GZO surface properties are modified so that their use as back contacts on a-Si solar cells is enhanced. Texturing is performed by simple dry plasma etching in a CVD process chamber,at power=100 W, substrate temperature=190 C (temperature is held at 190 C because thin film solar cells are damaged above 200 C), pressure=400 Pa and process gas H{sub 2} flow=700 sccm. Conventional a-Si solar cells are fabricated with and without GZO back contact surface treatment. Comparison of the with/without texturing GZO films shows that plasma etching increases optical scattering reflectance and reflection haze. SEM and TEM are used to evaluate the morphological treatment-induced changes in the films. Comparison of the a-Si solar cells with/without texturing shows that the plasma treatment increases both the short-circuit current density and fill factor. Consequently, a-Si solar cell efficiency is relatively improved by 4.6%. (author)

  9. Tuning of undoped ZnO thin film via plasma enhanced atomic layer deposition and its application for an inverted polymer solar cell

    Directory of Open Access Journals (Sweden)

    Mi-jin Jin

    2013-10-01

    Full Text Available We studied the tuning of structural and optical properties of ZnO thin film and its correlation to the efficiency of inverted solar cell using plasma-enhanced atomic layer deposition (PEALD. The sequential injection of DEZn and O2 plasma was employed for the plasma-enhanced atomic layer deposition of ZnO thin film. As the growth temperature of ZnO film was increased from 100 °C to 300 °C, the crystallinity of ZnO film was improved from amorphous to highly ordered (002 direction ploy-crystal due to self crystallization. Increasing oxygen plasma time in PEALD process also introduces growing of hexagonal wurtzite phase of ZnO nanocrystal. Excess of oxygen plasma time induces enhanced deep level emission band (500 ∼ 700 nm in photoluminescence due to Zn vacancies and other defects. The evolution of structural and optical properties of PEALD ZnO films also involves in change of electrical conductivity by 3 orders of magnitude. The highly tunable PEALD ZnO thin films were employed as the electron conductive layers in inverted polymer solar cells. Our study indicates that both structural and optical properties rather than electrical conductivities of ZnO films play more important role for the effective charge collection in photovoltaic device operation. The ability to tune the materials properties of undoped ZnO films via PEALD should extend their functionality over the wide range of advanced electronic applications.

  10. Spectrum of Optically Thin Advection Dominated Accretion Flow around a Black Hole Application to Sgr A*

    CERN Document Server

    Manmoto, T; Kusunose, M

    1997-01-01

    The global structure of optically thin advection dominated accretion flows which are composed of two-temperature plasma around black holes is calculated. We adopt the full set of basic equations including the advective energy transport in the energy equation for the electrons. The spectra emitted by the optically thin accretion flows are also investigated. The radiation mechanisms which are taken into accout are bremsstrahlung, synchrotron emission, and Comptonization. The calculation of the spectra and that of the structure of the accretion flows are made to be completely consistent by calculating the radiative cooling rate at each radius. As a result of the advection domination for the ions, the heat transport from the ions to the electrons becomes practically zero and the radiative cooling balances with the advective heating in the energy equation of the electrons. Following up on the successful work of Narayan et al. (1995), we applied our model to the spectrum of Sgr A*. We find that the spectrum of Sgr ...

  11. Deducing effective light transport parameters in optically thin systems

    CERN Document Server

    Mazzamuto, Giacomo; Toninelli, Costanza; Wiersma, Diederik

    2015-01-01

    We present an extensive Monte Carlo study on light transport in optically thin slabs, addressing both axial and transverse propagation. We completely characterize the so-called ballistic-to-diffusive transition, notably in terms of the spatial variance of the transmitted/reflected profile. We test the validity of the prediction cast by diffusion theory, that the spatial variance should grow independently of absorption and, to a first approximation, of the sample thickness and refractive index contrast. Based on a large set of simulated data, we build a freely available look-up table routine allowing reliable and precise determination of the microscopic transport parameters starting from robust observables which are independent of absolute intensity measurements. We also present the Monte Carlo software package that was developed for the purpose of this study.

  12. Optically transparent frequency selective surfaces on flexible thin plastic substrates

    Energy Technology Data Exchange (ETDEWEB)

    Dewani, Aliya A., E-mail: a.ashraf@griffith.edu.au; O’Keefe, Steven G.; Thiel, David V.; Galehdar, Amir [School Of Electrical Engineering, Griffith University, Brisbane, 4111 (Australia)

    2015-02-15

    A novel 2D simple low cost frequency selective surface was screen printed on thin (0.21 mm), flexible transparent plastic substrate (relative permittivity 3.2). It was designed, fabricated and tested in the frequency range 10-20 GHz. The plane wave transmission and reflection coefficients agreed with numerical modelling. The effective permittivity and thickness of the backing sheet has a significant effect on the frequency characteristics. The stop band frequency reduced from 15GHz (no backing) to 12.5GHz with polycarbonate. The plastic substrate thickness beyond 1.8mm has minimal effect on the resonant frequency. While the inner element spacing controls the stop-band frequency, the substrate thickness controls the bandwidth. The screen printing technique provided a simple, low cost FSS fabrication method to produce flexible, conformal, optically transparent and bio-degradable FSS structures which can find their use in electromagnetic shielding and filtering applications in radomes, reflector antennas, beam splitters and polarizers.

  13. Optical study of dye-containing fluorinated polyimide thin films

    Science.gov (United States)

    Quaranta, A.; Carturan, S.; Maggioni, G.; Della Mea, G.; Ischia, M.; Campostrini, R.

    Thin films of dye-containing fluorinated polyimide have been obtained by adding the dye powder to the polyamic acid resin and by spin coating the resulting solution on silica and silicon substrates. 6FDA (4,4'-hexafluoroisopropylidene diphthalic anhydride) and DAB (diaminobenzophenone) have been used as precursor monomers and rhodamine B as dye. The influence of the rhodamine-B molecule on the completeness of the imidization process has been studied by coupled thermogravimetric and mass-spectrometric analyses (TG-MS) of pure and doped polyamic acid resin and by FT-IR analysis of samples before and after curing. Optical emission, excitation and absorption spectra have been collected in order to study spectroscopic and aggregation characteristics of rhodamine as a function of the deposition parameters.

  14. Model of a thin film optical fiber fluorosensor

    Science.gov (United States)

    Egalon, Claudio O.; Rogowski, Robert S.

    1991-03-01

    The efficiency of core-light injection from sources in the cladding of an optical fiber is modeled analytically by means of the exact field solution of a step-profile fiber. The analysis is based on the techniques by Marcuse (1988) in which the sources are treated as infinitesimal electric currents with random phase and orientation that excite radiation fields and bound modes. Expressions are developed based on an infinite cladding approximation which yield the power efficiency for a fiber coated with fluorescent sources in the core/cladding interface. Marcuse's results are confirmed for the case of a weakly guiding cylindrical fiber with fluorescent sources uniformly distributed in the cladding, and the power efficiency is shown to be practically constant for variable wavelengths and core radii. The most efficient fibers have the thin film located at the core/cladding boundary, and fibers with larger differences in the indices of refraction are shown to be the most efficient.

  15. Optical Constants of Palladium Phthalocyanine Derivative Thin Films

    Institute of Scientific and Technical Information of China (English)

    吴谊群; 顾冬红; 干福熹; 王俊东; 陈耐生

    2002-01-01

    Ellipsometric parameters ora series of spin-coated thin films of palladium phthalocyanine derivatives with bromine and tetraalkoxyl substitutes (PdPc(OC8H17)4Brm, m = 0, 2, 3, 4) are determined from a rotating analyserpolarizer type of scanning ellipsometer. The optical, dielectric constants and absorption coefficients of the films in the 500-800nm wavelength region are reported. The results show that refractive index N (N = n- k),dielectric constant ε (ε =ε1 -ε2) and absorption coefficient α in the region 500-800nm are influenced by bromine atom substituted on the conjugated phthalocyanine ring regularly. It is found that there is approximately a linear relationship between the resonance absorption wavelengths of the films and the number of bromine atoms substituted on the phthalocyanine ring.

  16. Ionization Modeling Astrophysical Gaseous Structures. I. The Optically Thin Regime

    CERN Document Server

    Churchill, Christopher W; Medina, Amber; Vliet, Jacob R Vander

    2014-01-01

    We present a code for modelling the ionization conditions of optically thin astrophysical gas structures. Given the gas hydrogen density, equilibrium temperature, elemental abundances, and the ionizing spectrum, the code solves the equilibrium ionization fractions and number densities for all ions from hydrogen to zinc. The included processes are photoionization, Auger ionization, direct collisional ionization, excitation auto-ionization, charge exchange ionization, two-body radiative recombination, dielectronic recombination, and charge exchange recombination. The ionizing spectrum can be generalized to include the ultraviolet background (UVB) and/or Starburst99 stellar populations of various masses, ages, metallicities, and distances. The ultimate goal with the code is to provide fast computation of the ionization conditions of gas in N-body + hydrodynamics cosmological simulations, in particular adaptive mesh refinement codes, in order to facilitate absorption line analysis of the simulated gas for compari...

  17. Optically transparent frequency selective surfaces on flexible thin plastic substrates

    Science.gov (United States)

    Dewani, Aliya A.; O'Keefe, Steven G.; Thiel, David V.; Galehdar, Amir

    2015-02-01

    A novel 2D simple low cost frequency selective surface was screen printed on thin (0.21 mm), flexible transparent plastic substrate (relative permittivity 3.2). It was designed, fabricated and tested in the frequency range 10-20 GHz. The plane wave transmission and reflection coefficients agreed with numerical modelling. The effective permittivity and thickness of the backing sheet has a significant effect on the frequency characteristics. The stop band frequency reduced from 15GHz (no backing) to 12.5GHz with polycarbonate. The plastic substrate thickness beyond 1.8mm has minimal effect on the resonant frequency. While the inner element spacing controls the stop-band frequency, the substrate thickness controls the bandwidth. The screen printing technique provided a simple, low cost FSS fabrication method to produce flexible, conformal, optically transparent and bio-degradable FSS structures which can find their use in electromagnetic shielding and filtering applications in radomes, reflector antennas, beam splitters and polarizers.

  18. Optical Characterization of Different Thin Film Module Technologies

    Directory of Open Access Journals (Sweden)

    R. Ebner

    2015-01-01

    Full Text Available For a complete quality control of different thin film module technologies (a-Si, CdTe, and CIS a combination of fast and nondestructive methods was investigated. Camera-based measurements, such as electroluminescence (EL, photoluminescence (PL, and infrared (IR technologies, offer excellent possibilities for determining production failures or defects in solar modules which cannot be detected by means of standard power measurements. These types of optical measurement provide high resolution images with a two-dimensional distribution of the characteristic features of PV modules. This paper focuses on quality control and characterization using EL, PL, and IR imaging with conventional cameras and an alternative excitation source for the PL-setup.

  19. Real-time optical plasma boundary reconstruction for plasma position control at the TCV Tokamak

    NARCIS (Netherlands)

    Hommen, G.; Baar, M. de; Duval, B.P.; Andrebe, Y.; Le, H.B.; Klop, M.A.; Doelman, N.J.; Witvoet, G.; Steinbuch, M.

    2014-01-01

    A dual, high speed, real-time visible light camera setup was installed on the TCV tokamak to reconstruct optically and in real-time the plasma boundary shape. Localized light emission from the plasma boundary in tangential view, broadband visible images results in clearly resolved boundary edge-feat

  20. Effect of Hydrogen Dilution on Growth of Silicon Nanocrystals Embedded in Silicon Nitride Thin Film bv Plasma-Enhanced CVD

    Institute of Scientific and Technical Information of China (English)

    DING Wenge; ZHEN Lanfang; ZHANG Jiangyong; LI Yachao; YU Wei; FU Guangsheng

    2007-01-01

    An investigation was conducted into the effect of hydrogen dilution on the mi-crostructure and optical properties of silicon nanograins embedded in silicon nitride (Si/SiNx) thin film deposited by the helicon wave plasma-enhanced chemical vapour deposition technique. With Ar-diluted SiH4 and N2 as the reactant gas sources in the fabrication of thin film, the film was formed at a high deposition rate. There was a high density of defect at the amorphous silicon (a-Si)/SiNx interface and a relative low optical gap in the film. An addition of hydrogen into the reactant gas reduced the film deposition rate sharply. The silicon nanograins in the SiNx matrix were in a crystalline state, and the density of defects at the silicon nanocrystals (nc-Si)/SiNx interface decreased significantly and the optical gap of the films widened. These results suggested that hydrogen activated by the plasma could not only eliminate in the defects between the interface of silicon nanograins and SiNx matrix, but also helped the nanograins transform from the amorphous into crystalline state. By changing the hydrogen dilution ratio in the reactant gas sources, a tunable band gap from 1.87 eV to 3.32 eV was obtained in the Si/SiNx film.

  1. Layer-by-layer thinning of MoSe2 by soft and reactive plasma etching

    Science.gov (United States)

    Sha, Yunfei; Xiao, Shaoqing; Zhang, Xiumei; Qin, Fang; Gu, Xiaofeng

    2017-07-01

    Two-dimensional (2D) transition metal dichalcogenides (TMDs) like molybdenum diselenide (MoSe2) have recently gained considerable interest since their properties are complementary to those of graphene. Unlike gapless graphene, the band structure of MoSe2 can be changed from the indirect band gap to the direct band gap when MoSe2 changed from bulk material to monolayer. This transition from multilayer to monolayer requires atomic-layer-precision thining of thick MoSe2 layers without damaging the remaining layers. Here, we present atomic-layer-precision thinning of MoSe2 nanaosheets down to monolayer by using SF6 + N2 plasmas, which has been demonstrated to be soft, selective and high-throughput. Optical microscopy, atomic force microscopy, Raman and photoluminescence spectra suggest that equal numbers of MoSe2 layers can be removed uniformly regardless of their initial thickness, without affecting the underlying SiO2 substrate and the remaining MoSe2 layers. By adjusting the etching rates we can achieve complete MoSe2 removal and any disired number of MoSe2 layers including monolayer. This soft plasma etching method is highly reliable and compatible with the semiconductor manufacturing processes, thereby holding great promise for various 2D materials and TMD-based devices.

  2. Pulsed Plasma Polymerization of Perfluorooctyl Ethylene for Transparent Hydrophobic Thin Coatings

    Science.gov (United States)

    Liu, Xiaojun; Wang, Lei; Hao, Jie; Chu, Liqiang

    2015-12-01

    Herein we report on the deposition of transparent hydrophobic thin coatings by radio frequency plasma polymerization (PP) of perfluorooctyl ethylene (PFOE) in both pulsed and continuous wave (CW) modes. The chemical compositions of the resulting PP-PFOE coatings were confirmed by means of Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The thicknesses and surface morphologies of the coatings were examined using surface plasmon resonance spectroscopy and atomic force microscopy. The surface wetting properties and optical transmittance were measured using a water contact angle goniometer and UV-vis spectroscopy. The FT-IR and XPS data showed that the PP-PFOE coatings deposited in the pulsed mode had a higher retention of CF2 groups compared to those from the CW mode. While the water contact angle of the freshly deposited PP-PFOE from the pulsed mode showed a decrease from 120 degrees to 111 degrees in the first two days, it then remained almost unchanged up to 45 days. The UV-vis data indicated that a PP-PFOE coating 30.6 nm thick had a light transmittance above 90% in the UV and visible ranges. The deposition rates under various plasma conditions are also discussed. supported by the Tianjin Research Program of Application Foundation and Advanced Technology, China (No. 12JCYBJC31700) and the Program for New Century Excellent Talents in University, China (No. NCET-12-1064)

  3. Ultra-thin and low-power optical interconnect module based on a flexible optical printed circuit board

    Science.gov (United States)

    Hwang, Sung Hwan; Lee, Woo-Jin; Kim, Myoung Jin; Jung, Eun Joo; Kim, Gye Won; An, Jong Bae; Jung, Ki Young; Cha, Kyung Soon; Rho, Byung Sup

    2012-07-01

    We describe an ultra-thin and low-power optical interconnect module for mobile electronic devices such as mobile phones and notebooks. The module was fabricated by directly packaging optic and electronic components onto a thin and flexible optical printed circuit board having a size of 70×8×0.25 mm. The completed active module has features of thinness (0.5 mm), small size (7×5 mm), very low total power consumption (15.88 mW), and high data rate transmissions (2.5 Gbps).

  4. Growth of γ-alumina thin films by pulsed laser deposition and plasma diagnostic

    Science.gov (United States)

    Yahiaoui, K.; Abdelli-Messaci, S.; Messaoud Aberkane, S.; Siad, M.; Kellou, A.

    2017-07-01

    The present work discusses about the synthesis of alumina thin films, which have applications in current and next-generation solid-state electronic devices due to their attractive properties. Alumina thin films were synthesized by pulsed laser deposition at different oxygen pressures and substrate temperatures. The dependence of substrate temperature, oxygen pressure, and the deposition time on the properties of the films has been observed by growing three series of alumina thin films on Si (100). The first films are synthesized using substrate temperatures ranging from room temperature to 780 °C at 0.01 mbar of O2. The second series was realized at a fixed substrate temperature of 760 °C and varied oxygen pressure (from 0.005 to 0.05 mbar). The third set of series was elaborated at different deposition times (from 15 to 60 min) while the oxygen pressure and the substrate temperature were fixed at 0.01 mbar and 760 °C, respectively. The films were characterized using X-ray diffractometer (XRD) for structural analysis, a scanning electron microscope for morphological analysis, a nano-indenter for mechanical analysis (hardness and Young's modulus), and Rutherford backscattering spectroscopy for thickness and stoichiometry measurements. Using optical emission spectroscopy, plasma diagnostic was carried out both in the vacuum and in the presence of oxygen with a pressure ranging from 0.01 to 0.05 mbar. Several neutral, ionic, and molecular species were identified such as Al, Al+, and Al++ in vacuum and in oxygen ambiance, O and AlO molecular bands in oxygen-ambient atmosphere. The spatiotemporal evolution of the most relevant species was achieved and their velocities were estimated. The highest amount of crystallized alumina in γ-phase was found in the films elaborated under 0.01 mbar of O2, at a substrate temperature of 780 °C, and a deposition time of 60 min.

  5. Investigation of local and nonlocal nonlinear optical refraction effect in IZO thin films

    Science.gov (United States)

    Htwe, Zin Maung; Zhang, Yun-Dong; Yao, Cheng-Bao; Li, Hui; Yuan, Ping

    2016-10-01

    We report the local and nonlocal nonlinear optical refraction properties of indium doped zinc oxide (IZO) thin films using closed aperture Z-scan technique. The Z-scan results show the films have positive nonlinear optical refraction properties. The nonlocal parameter m of samples is increased with indium. In both of local and nonlocal studies, the nonlinear optical refractions of thin films were increased with In contents and laser energy. This relation reveals the role of In composition in IZO affects on the nonlinear optical responses of the films. These results make the IZO thin films as the promising application in optoelectronics devices.

  6. Choroidal thinning in high myopia measured by optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Ikuno Y

    2013-05-01

    Full Text Available Yasushi Ikuno, Satoko Fujimoto, Yukari Jo, Tomoko Asai, Kohji NishidaDepartment of Ophthalmology, Osaka University Graduate School of Medicine, Osaka, JapanPurpose: To investigate the rate of choroidal thinning in highly myopic eyes.Patients and methods: A retrospective observational study of 37 eyes of 26 subjects (nine males and 17 females, mean age 39.6 ± 7.7 years with high myopia but no pathologies who had undergone spectral domain optical coherence tomography and repeated the test 1 year later (1 ± 0.25 year at Osaka University Hospital, Osaka, Japan. Patients older than 50 years with visual acuity worse than 20/40 or with whitish chorioretinal atrophy involving the macula were excluded. Two masked raters measured the choroidal thicknesses (CTs at the foveda, 3 mm superiorly, inferiorly, temporally, and nasally on the images and averaged the values. The second examination was about 365 days after the baseline examination. The CT reduction per year (CTRPY was defined as (CT 1 year after - baseline CT/days between the two examinations × 365. The retinal thicknesses were also investigated.Results: The CTRPY at the fovea was −1.0 ± 22.0 µm (range –50.2 to 98.5 at the fovea, –6.5 ± 24.3 µm (range −65.8 to 90.2 temporally, –0.5 ± 22.3 µm (range –27.1 to 82.5 nasally, –9.7 ± 21.7 µm (range –40.1 to 60.1 superiorly, and –1.4 ± 25.5 µm (range –85.6 to 75.2 inferiorly. There were no significant differences in the CTRPY at each location (P = 0.34. The CT decreased significantly (P < 0.05 only superiorly. The superior CTRPY was negatively correlated with the axial length (P < 0.05. The retinal thickness at the fovea did not change. Stepwise analysis for CTRPY selected axial length (P = 0.04, R2 = 0.13 and age (P = 0.08, R2 = 0.21 as relevant factors.Conclusions: The highly myopic choroid might gradually thin and be affected by many factors. Location and axial length are key factors to regulate the rate of choroidal

  7. Optical diagnostics of femtosecond laser plasmas

    Institute of Scientific and Technical Information of China (English)

    LI; Yutong

    2001-01-01

    [1]Benattar, R., Popovics, C., Sigel, R., Polarized light interferometer for laser fusion studies, Rev. Sci. Instrum., 979, 50(2): 583.[2]Young, P. E., Hammer, J. H., Wilks, S. C. et al., Laser beam propagation and channel formation in underdense plasmas, Phys. Plasmas, 995, 2(7): 2825.[3]Zhang, P., He, J.T., Chen, D.B. et al., Effects of a prepulse on γ-ray radiation produced by a femtosecond laser with only mJ energy, Phys. Rev. E., 998, 57: R3746.[4]Stamper, J. A., Review on spontaneous magnetic fields in laser-produced plasmas: phenomena and measurements, Laser and Particle Beams, 99, 9(4): 84.[5]Stamper, J. A., McLean, E. A., Ripin, B. H., Studies of spontaneous magnetic fields in laser-produced plasmas by Faraday rotation, Phys. Rev. Lett., 978, 40(8): 77.[6]Raven, A., Willi, O., Rumsby, P. T., Megagauss magnetic field profiles in laser-produced plasmas, Phys. Rev. Lett., 978, 4(8): 554.[7]Burgess, M. D. J., Luther-Davis, B., Nugent, K. A., An experimental study of magnetic fields in plasmas created by high intensity one micron laser radiation, Phys. Fluids, 985, 28(7): 2286.[8]Borghesi, M., Mackinnon, A. J., Bell, A. R. et al., Megagauss magnetic field generation and plasma jet formation on solid targets irradiated by an ultraintense picosecond laser pulse, Phys. Rev. Lett., 998, 8(): 2.

  8. Optical properties of plasma deposited amorphous carbon nitride films on polymer substrates

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, S.H., E-mail: abo_95@yahoo.co [Physics Department, Faculty of Science, Sohag University, 82524 Sohag (Egypt); El-Hossary, F.M. [Physics Department, Faculty of Science, Sohag University, 82524 Sohag (Egypt); Gamal, G.A.; Kahlid, M.M. [Physics Department, Faculty of Science, South Valley University, 83523 Qena (Egypt)

    2010-01-01

    Amorphous carbon nitride thin films were deposited on polymer substrates using radio frequency (rf) plasma in a mixture of nitrogen (N{sub 2}) and acetylene (C{sub 2}H{sub 2}) gasses. The samples were prepared at different rf plasma power (350, 400, 450, 500, and 550 W), at constant plasma exposure time of 10 min, and constant N{sub 2}/C{sub 2}H{sub 2} ratio of 50%. The crystal structure and surface morphology of the prepared samples were examined using X-ray diffraction and atomic force microscopy analysis, respectively. The absence of the carbon nitride diffraction peaks confirms the amorphous nature of these films. The root mean square roughness of the films increased from 3.77 to 25.22 nm as the power increased from 350 to 550 W. The thickness and the deposition rate were found to increase with increasing plasma power. Over the whole studied wavelength range, from 200 to 2500 nm, the transmittance decreased with increasing plasma power. A shift in the onset of absorption towards higher wavelengths with increasing plasma power, indicating a decrease in the optical band gap, has been observed. The refractive index values were found to decrease while the extinction coefficient increased with increasing plasma power.

  9. Present status of thin oxide films creation in a microwave plasma

    Energy Technology Data Exchange (ETDEWEB)

    Loncar, G. (Ceske Vysoke Uceni Technicke, Prague (Czechoslovakia). Fakulta Jaderna a Fysikalne Inzenyrska); Musil, J.; Bardos, L. (Ceskoslovenska Akademie Ved, Prague. Ustav Fyziky Plazmatu)

    1980-01-01

    The paper summarizes present knowledge of the creation of thin films in both isotropic and magnetoactive plasmas. It analyses conditions under which films in the microwave plasma can be created and shows how the growth rates and properties of films depend on microparameters of the plasma. On the basis of plasma floating potential measurements it is shown why the creation of thin films in microwave discharges takes place at high electron plasma densities (N > or approximately 10/sup 12/ cm/sup -3/) only. Besides, it describes properties of formed films, underlines the negative role of fast electrons in forming good quality films and gives recommendation of how to avoid their generation. Considerable attention is devoted also to a comparison of film creation in pulsed and continuous plasmas. The possibility of film creation at low temperatures by the deposition technique utilizing microwave excitation of molecular gases is given.

  10. Evolution of infrared spectra and optical emission spectra in hydrogenated silicon thin films prepared by VHF-PECVD

    Science.gov (United States)

    Hou, Guo-Fu; Geng, Xin-Hua; Zhang, Xiao-Dan; Sun, Jian; Zhang, Jian-Jun; Zhao, Ying

    2011-07-01

    A series of hydrogenated silicon thin films with varying silane concentrations have been deposited by using very high frequency plasma enhanced chemical vapor deposition (VHF-PECVD) method. The deposition process and the silicon thin films are studied by using optical emission spectroscopy (OES) and Fourier transfer infrared (FTIR) spectroscopy, respectively. The results show that when the silane concentration changes from 10% to 1%, the peak frequency of the Si-H stretching mode shifts from 2000 cm-1 to 2100 cm-1, while the peak frequency of the Si—H wagging—rocking mode shifts from 650 cm-1 to 620 cm-1. At the same time the SiH/Hα intensity ratio in the plasma decreases gradually. The evolution of the infrared spectra and the optical emission spectra demonstrates a morphological phase transition from amorphous silicon (a-Si:H) to microcrystalline silicon (μc-Si:H). The structural evolution and the μc-Si:H formation have been analyzed based on the variation of Hα and SiH intensities in the plasma. The role of oxygen impurity during the plasma process and in the silicon films is also discussed in this study.

  11. Optical and electrical properties of nickel xanthate thin films

    Indian Academy of Sciences (India)

    İ A Kariper; T Özpozan

    2014-05-01

    Nickel xanthate thin films (NXTF) were successfully deposited by chemical bath deposition, on to amorphous glass substrates, as well as on - and -silicon, indium tin oxide and poly(methyl methacrylate). The structure of the films was analysed by X-ray diffraction (XRD), far-infrared spectrum (FIR), mid-infrared (MIR) spectrum, nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM). These films were investigated from their structural, optical and electrical properties point of view. Uniform distribution of grains was clearly observed from the photographs taken by scanning electron microscope (SEM). The higher transmittance was about 50–60% after optimizing the parameters of deposition time and temperature (4 h, 50 °C). The optical bandgap of the NXTF was graphically estimated as 3.90–3.96 eV. The resistivity of the films was calculated as 62.6–90.7 .cm on commercial glass depending on the film thickness and 62.2–74.5 .cm on the other substrates. The MIR and FIR spectra of the films conformed to the literature and their solid powder forms. The expected peaks of nickel xanthate were observed in NMR analysis on glass. The films were dipped into chloroform as organic solvent and were analysed by NMR.

  12. Dust Migration and Morphology in Optically Thin Circumstellar Gas Disks

    CERN Document Server

    Takeuchi, T; Takeuchi, Taku; Artymowicz, Pawel

    2001-01-01

    We analyze the dynamics of gas-dust coupling in the presence of stellar radiation pressure in circumstellar gas disks, which are in a transitional stage between the gas-dominated, optically thick, primordial nebulae, and the dust-dominated, optically thin Vega-type disks. Dust undergo radial migration, seeking a stable equilibrium orbit in corotation with gas. The migration of dust gives rise to radial fractionation of dust and creates a variety of possible observed disk morphologies, which we compute by considering the equilibrium between the dust production and the dust-dust collisions removing particles from their equilibrium orbits. Sand-sized and larger grains are distributed throughout most of the gas disk, with concentration near the gas pressure maximum in the inner disk. Smaller grains (typically in the range of 10 to 200 micron) concentrate in a prominent ring structure in the outer region of the gas disk (presumably at radius 100 AU), where gas density is rapidly declining with radius. The width an...

  13. Influence of ignition condition on the growth of silicon thin films using plasma enhanced chemical vapour deposition

    Institute of Scientific and Technical Information of China (English)

    Zhang Hai-Long; Liu Feng-Zhen; Zhu Mei-Fang; Liu Jin-Long

    2012-01-01

    The influences of the plasma ignition condition in plasma enhanced chemical vapour deposition (PECVD) on the interfaces and the microstructures of hydrogenated microcrystalline Si (μc-Si:H) thin films are investigated.The plasma ignition condition is modified by varying the ratio of SiH4 to H2 (RH).For plasma ignited with a constant gas ratio,the time-resolved optical emission spectroscopy presents a low value of the emission intensity ratio of Hα to SiH(IHα/IsiH) at the initial stage,which leads to a thick amorphous incubation layer.For the ignition condition with a profiling RH,the higher IHα/IsiH values are realized.By optimizing the RH modulation,a uniform crystallinity along the growth direction and a denser μc-Si:H film can be obtained.However,an excessively high IHα/IsiH* may damage the interface properties,which is indicated by capacitance-voltage (C-V) measurements.Well controlling the ignition condition is critically important for the applications of Si thin films.

  14. Photocatalytic property of titanium dioxide thin films deposited by radio frequency magnetron sputtering in argon and water vapour plasma

    Energy Technology Data Exchange (ETDEWEB)

    Sirghi, L., E-mail: lsirghi@uaic.ro [Department of Physics, Alexandru Ioan Cuza University, Blvd. Carol I, 11, Iasi, 700506 (Romania); Hatanaka, Y. [Research Institute of Electronics, Shizuoka University, 3-5-1, Johoku Naka-ku Hamamatsu, 432-8011 (Japan); Sakaguchi, K. [Faculty of Engineering, Aichi University of Technology, 50-2 Manori, Nishihazama, Gamagori, 443-0047 Aichi (Japan)

    2015-10-15

    Highlights: • TiOx thin films were deposited by radio frequency magnetron sputtering in Ar and Ar/H{sub 2}O plasma. • The deposited films contain OH groups in their bulk structure irrespective of the water content of the working gas. • The structure and photocatalytic activity of the deposited films were studied. - Abstract: The present work is investigating the photocatalytic activity of TiO{sub 2} thin films deposited by radiofrequency magnetron sputtering of a pure TiO{sub 2} target in Ar and Ar/H{sub 2}O (pressure ratio 40/3) plasmas. Optical absorption, structure, surface morphology and chemical structure of the deposited films were comparatively studied. The films were amorphous and included a large amount of hydroxyl groups (about 5% of oxygen atoms were bounded to hydrogen) irrespective of the intentional content of water in the deposition chamber. Incorporation of hydroxyl groups in the film deposited in pure Ar plasma is explained as contamination of the working gas with water molecules desorbed by plasma from the deposition chamber walls. However, intentional input of water vapour into the discharge chamber decreased the deposition speed and roughness of the deposited films. The good photocatalytic activity of the deposited films could be attributed hydroxyl groups in their structures.

  15. Interleukin-7 Plasma Levels in Human Differentiate Anorexia Nervosa, Constitutional Thinness and Healthy Obesity

    Science.gov (United States)

    Germain, Natacha; Viltart, Odile; Loyens, Anne; Bruchet, Céline; Nadin, Katia; Wolowczuk, Isabelle; Estour, Bruno; Galusca, Bogdan

    2016-01-01

    Introduction Interleukin-7 (IL-7) is a cytokine involved in energy homeostasis as demonstrated in rodents. Anorexia nervosa is characterized by restrained eating behavior despite adaptive orexigenic regulation profile including high ghrelin plasma levels. Constitutional thinness is a physiological condition of resistance to weight gain with physiological anorexigenic profile including high Peptide YY plasma level. Healthy obesity can be considered as a physiological state of resistance to weight loss with opposite appetite regulating profile to constitutional thinness including low Peptide YY plasma level. No studies in IL-7 are yet available in those populations. Therefore we evaluated circadian plasma levels of IL-7 in anorexia nervosa compared to constitutional thinness, healthy obese and control females. Materials and Methods 10 restrictive-type anorexia nervosa women, 5 bingeing/purging anorexia nervosa woman, 5 recovered restrictive anorexia nervosa women, 4 bulimic females, 10 constitutional thinness women, 7 healthy obese females, and 10 normal weight women controls were enrolled in this cross-sectional study, performed in endocrinology unit and academic laboratory. Twelve-point circadian profiles of plasma IL-7 levels were measured in each subject. Results 24h mean IL-7 plasma levels (pg/ml, mean±SEM) were decreased in restrictive-type anorexia nervosa (123.4±14.4, pobese patients (51±3.2, pobesity, with low IL-7, is once again in mirror image of constitutional thinness with normal high IL-7. PMID:27611669

  16. Experimental Study of the Plasma Fluorination of Y-Ba-Cu-O Thin Films

    Institute of Scientific and Technical Information of China (English)

    李琴; 傅泽禄; 吉争鸣; 冯一军; 康琳; 杨森祖; 吴培亨; 王晓书; 叶宇达

    2002-01-01

    We have experimentally studied the surface modifications of Y-Ba-Cu-O (YBCO) thin films using CF4plasma. The intensity of the plasma fluorination was controlled by changing the liasing voltage and the time of the plasma treatment. Microstructural analyses reveal that the oxygen content of the YBCO thin films was changed. Transport measurements of sufficient fluorinated YBCO films imply that the films changed totally into an oxygen-deficient semi-conducting state. From these experimental results, we believe that plasma fluorination is quite a useful method to form controllable a thin barrier layer in fabricating interface engineered junctions and to form a stable narrow weak-link region in fabricating planar superconductor-normal-superconductor junctions.

  17. AC plasma induced modifications in Sb{sub 2}S{sub 3} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Calixto-Rodriguez, M; Martinez, H [Instituto de Ciencias Fisicas, Universidad Nacional Autonoma de Mexico, Apartado Postal 48-3, 62210, Cuernavaca, Morelos (Mexico); Castillo, F [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, 04510, Mexico D. F. (Mexico); Pena, Y [Universidad Autonoma de Nuevo Leon, Facultad de Ciencias Quimicas, Pedro de Alba s/n, Cd. Universitaria, San Nicolas de los Garza, N.L (Mexico); Sanchez-Juarez, A, E-mail: ciro@nucleares.unam.m [Centro de Investigacion en EnergIa, Universidad Nacional Autonoma de Mexico, Privada Xochicalco s/n Col. Centro, Temixco, Morelos, C.P. 62580 (Mexico)

    2010-01-01

    Sb{sub 2}S{sub 3} thin films, deposited by the chemical bath deposition method, were treated with N{sub 2} plasma at 3.0 Torr during several minutes. The as-prepared Sb{sub 2}S{sub 3} thin films and films treated with N{sub 2} plasma have been characterized using several techniques. X-ray diffraction studies have shown that plasma treatment induced recrystallization on the as-prepared Sb{sub 2}S{sub 3}thin films. The band gap values decreased from 2.37 to 1.82 eV after plasma treatment, and the electrical conductivity increased from 10{sup 9} to 10{sup 7} ({Omega}cm){sup -1} due to the annealing effect.

  18. Experimental study of the plasma fluorination of Y-Ba-Cu-O thin films

    CERN Document Server

    Li Qi; Ji Zheng Ming; Feng Yi Jun; Kang Lin; Yang Sen Zu; Wu Pei Heng; Wang Xiao Shu; Ye Yuda

    2002-01-01

    The authors have experimentally studied the surface modifications of Y-Ba-Cu-O (YBCO) thin films using CF sub 4 plasma. The intensity of the plasma fluorination was controlled by changing the biasing voltage and the time of the plasma treatment. Microstructural analyses reveal that the oxygen content of the YBCO thin films was changed. Transport measurements of sufficient fluorinated YBCO films imply that the films changed totally into an oxygen-deficient semi-conducting state. From these experimental results, the authors believe that plasma fluorination is quite a useful method to form controllable a thin barrier layer in fabricating interface engineered junctions and to form a stable narrow weak-link region in fabricating planar superconductor-normal-superconductor junctions

  19. Instrumentation in Support of Research on Bio-optical Thin Layers in Coastal Waters

    Science.gov (United States)

    1997-09-30

    INSTRUMENTATION IN SUPPORT OF RESEARCH ON BIO -OPTICAL THIN LAYERS IN COASTAL WATERS Dian J. Gifford Graduate School of Oceanography University of...SUBTITLE Instrumentation in Support of Research on Bio -optical Thin Layers in Coastal Waters 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...Because the layers scatter both sound and light, they are important in a number of other disciplinary areas in ocean including bio -optics and acoustics

  20. Room temperature radio-frequency plasma-enhanced pulsed laser deposition of ZnO thin films

    Science.gov (United States)

    Huang, S.-H.; Chou, Y.-C.; Chou, C.-M.; Hsiao, V. K. S.

    2013-02-01

    In this study, we compared the crystalline structures, optical properties, and surface morphologies of ZnO thin films deposited on silicon and glass substrates by conventional pulsed laser deposition (PLD) and radio-frequency (RF) plasma-enhanced PLD (RF-PEPLD). The depositions were performed at room temperature under 30-100 mTorr pressure conditions. The RF-PEPLD process was found to have deposited a ZnO structure with preferred (0 0 2) c-axis orientation at a higher deposition rate; however, the RF-PEPLD process generated more defects in the thin films. The application of oxygen pressure to the RF-PEPLD process reduced defects effectively and also increased the deposition rate.

  1. Non-linear optics of nano-scale pentacene thin film

    Science.gov (United States)

    Yahia, I. S.; Alfaify, S.; Jilani, Asim; Abdel-wahab, M. Sh.; Al-Ghamdi, Attieh A.; Abutalib, M. M.; Al-Bassam, A.; El-Naggar, A. M.

    2016-07-01

    We have found the new ways to investigate the linear/non-linear optical properties of nanostructure pentacene thin film deposited by thermal evaporation technique. Pentacene is the key material in organic semiconductor technology. The existence of nano-structured thin film was confirmed by atomic force microscopy and X-ray diffraction. The wavelength-dependent transmittance and reflectance were calculated to observe the optical behavior of the pentacene thin film. It has been observed the anomalous dispersion at wavelength λ 800. The non-linear refractive index of the deposited films was investigated. The linear optical susceptibility of pentacene thin film was calculated, and we observed the non-linear optical susceptibility of pentacene thin film at about 6 × 10-13 esu. The advantage of this work is to use of spectroscopic method to calculate the liner and non-liner optical response of pentacene thin films rather than expensive Z-scan. The calculated optical behavior of the pentacene thin films could be used in the organic thin films base advanced optoelectronic devices such as telecommunications devices.

  2. Compact collimated fiber optic array diagnostic for railgun plasma experiments

    Energy Technology Data Exchange (ETDEWEB)

    Tang, V; Solberg, J; Ferriera, T; Tully, L; Stephan, P

    2008-10-02

    We have developed and tested a compact collimated sixteen channel fiber optic array diagnostic for studying the light emission of railgun armature plasmas with {approx}mm spatial and sub-{micro}s temporal resolution. The design and operational details of the diagnostic are described. Plasma velocities, oscillation, and dimension data from the diagnostic for the Livermore Fixed Hybrid Armature experiment are presented and compared with 1-D simulations. The techniques and principles discussed allow the extension of the diagnostic to other railgun and related dense plasma experiments.

  3. Compact collimated fiber optic array diagnostic for railgun plasmas.

    Science.gov (United States)

    Tang, V; Solberg, J M; Ferriera, T J; Tully, L K; Stephan, P L

    2009-01-01

    We developed and tested a compact collimated 16 channel fiber optic array diagnostic for studying the light emission of railgun armature plasmas with approximately millimeter spatial and submicrosecond temporal resolution. The design and operational details of the diagnostic are described. Plasma velocities, oscillation, and dimension data from the diagnostic for the Livermore fixed hybrid armature experiment are presented and compared with one-dimensional simulations. The techniques and principles discussed allow the extension of the diagnostic to other railgun and related dense plasma experiments.

  4. Determination of optical constants and nonlinear optical coefficients of Violet 1-doped polyvinyl alcohol thin film

    Indian Academy of Sciences (India)

    Hussain A Badran; Alaa Y Al-Ahmad; Qusay M Ali Hassan; Chassib A Emshary

    2016-01-01

    The optical properties of Violet 1-doped polyvinyl alcohol (PVA) have been investigated using Wemble and Didomenico (WD) method. The optical constants such as refractive index , the dispersion energy , the oscillation energy 0, the lattice dielectric constant ∞, light frequency dielectric constant 0 and the ratio of carrier concentration to the effective mass /* have been determined using reflection spectra in the wavelength range 300–900 nm. The singlebeam Z-scan technique was used to determine the nonlinear optical properties of Violet 1:polyvinylalcohol (PVA) thin film. The experiments were performed using continuous wave (cw) laser with a wavelength of 635 nm. The calculated nonlinear refractive index of the film, $n_{2} = -2.79 \\times 10^{-7}$ cm2/Wand nonlinear absorption coefficient, $\\beta = 6.31\\times10^{−3}$ cm/W. Optical limiting characteristics of the dye-doped polymer film was studied. The result reveals that Violet 1 can be a promising material for optical limiting applications.

  5. Thin film technologies for optoelectronic components in fiber optic communication

    Science.gov (United States)

    Perinati, Agostino

    1998-02-01

    will grow at an annual average rate of 22 percent from 1.3 million fiber-km in 1995 to 3.5 million fiber-km in 2000. The worldwide components market-cable, transceivers and connectors - 6.1 billion in 1994, is forecasted to grow and show a 19 percent combined annual growth rate through the year 2000 when is predicted to reach 17.38 billion. Fiber-in-the-loop and widespread use of switched digital services will dominate this scenario being the fiber the best medium for transmitting multimedia services. As long as communication will partially replace transportation, multimedia services will push forward technology for systems and related components not only for higher performances but for lower cost too in order to get the consumers wanting to buy the new services. In the long distance transmission area (trunk network) higher integration of electronic and optoelectronic functions are required for transmitter and receiver in order to allow for higher system speed, moving from 2.5 Gb/s to 5, 10, 40 Gb/s; narrow band wavelength division multiplexing (WDM) filters are required for higher transmission capacity through multiwavelength technique and for optical amplifier. In the access area (distribution network) passive components as splitters, couplers, filters are needed together with optical amplifiers and transceivers for point-to-multipoint optical signal distribution: main issue in this area is the total cost to be paid by the customer for basic and new services. Multimedia services evolution, through fiber to the home and to the desktop approach, will be mainly affected by the availability of technologies suitable for component consistent integration, high yield manufacturing processes and final low cost. In this paper some of the optoelectronic components and related thin film technologies expected to mainly affect the fiber optic transmission evolution, either for long distance telecommunication systems or for subscriber network, are presented.

  6. Optical characterization of ZnO thin films deposited by RF magnetron sputtering method

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    This study investigated the process parameter effects on the structural and optical properties of ZnO thin film using radio frequency (RF) magnetron sputtering on amorphous glass substrates. The process parameters included RF power and working pressure. Results show that RF power was increased to promote the crystalline quality and decrease ZnO thin film defects. However, when the working pressure was increased to 3 Pa the ZnO thin film crystalline quality became worse. At a 200 W RF power and 1 Pa working pressure, the ZnO thin film with an optical band gap energy of 3.225 eV was obtained.

  7. Structural, electro-magnetic, and optical properties of Ba(Fe,Ni)2As2 single-crystal thin film

    Science.gov (United States)

    Yoon, Sejun; Seo, Yu-Seong; Lee, Seokbae; Weiss, Jeremy D.; Jiang, Jianyi; Oh, MyeongJun; Lee, Jongmin; Seo, Sehun; Jo, Youn Jung; Hellstrom, Eric E.; Hwang, Jungseek; Lee, Sanghan

    2017-03-01

    We investigated the superconducting transition temperature (T c), critical current density (J c) and optical properties of optimally doped Ba(Fe0.95Ni0.05)2As2 (Ni-Ba122) single-crystalline epitaxial thin films grown by pulsed laser deposition for the first time. The T c at zero resistivity was about 20.5 K and the J c at self-field and 4.2 K was 2.8 MA cm-2 calculated by the Bean model. The superconducting properties such as T c and J c of thin films are comparable to those of bulk single-crystal samples. The superfluid plasma frequency (λ p,S) of Ni-Ba122 thin film is ˜7033 cm-1 obtained by optical spectroscopic technique. Based on this plasma frequency, we obtained the London penetration depth (λ L), ˜226 nm at 8 K, which is comparable to those of optimally Co- and K-doped BaFe2As2 single crystals.

  8. Preparation of ion-exchange thin film using plasma processes. Plasma process wo mochiita ion kokansei usumaku no sakusei

    Energy Technology Data Exchange (ETDEWEB)

    Ogumi, Z.; Uchimoto, Y. (Kyoto University, Kyoto (Japan). Faculty of Engineering)

    1992-10-31

    The present report describes a study which aims at preparation of a new functional film by plasma polymerization. For this purpose, 4-vinylpyridine monomer is plasma-polymerized to obtain a thin film, which is quaternarized with 1-bromopropane to produce an anion exchange thin film, which is laminated on the surface of a cation-exchange film to make a mono-valent cation perm-selective film. In plasma-polymerization, the relations of polymerizing pressure, as parameter, to the deposition rate of the polymerizerd film and the characteristics of compound were clarified. In preparing the anion-exchange thin film, the preparation of uniform ultrathin films with no pinhole was attempted. For this purpose, the transference number of Cl[sup -] was measured so as to confirm that Cl[sup -] is uniformly distributed and fixed cation groups are distributed uniformly in the film. The perm-selective film exhibited a high mono-valent cation perm-selectivity while its film resistance was increased. This increase is found to be broken down to the resistance of the plasma-polymerization film layer and the resistance of the film interface. The latter arises from the implantation of nitrogen-cointaining species in the plasma onto the surface of the cation exchange film. 26 refs., 10 figs., 2 tabs.

  9. Nonlinear Optical Properties of Organic and Polymeric Thin Film Materials of Potential for Microgravity Processing Studies

    Science.gov (United States)

    Abdeldayem, Hossin; Frazier, Donald O.; Paley, Mark S.; Penn, Benjamin; Witherow, William K.; Bank, Curtis; Shields, Angela; Hicks, Rosline; Ashley, Paul R.

    1996-01-01

    In this paper, we will take a closer look at the state of the art of polydiacetylene, and metal-free phthalocyanine films, in view of the microgravity impact on their optical properties, their nonlinear optical properties and their potential advantages for integrated optics. These materials have many attractive features with regard to their use in integrated optical circuits and optical switching. Thin films of these materials processed in microgravity environment show enhanced optical quality and better molecular alignment than those processed in unit gravity. Our studies of these materials indicate that microgravity can play a major role in integrated optics technology. Polydiacetylene films are produced by UV irradiation of monomer solution through an optical window. This novel technique of forming polydiacetylene thin films has been modified for constructing sophisticated micro-structure integrated optical patterns using a pre-programmed UV-Laser beam. Wave guiding through these thin films by the prism coupler technique has been demonstrated. The third order nonlinear parameters of these films have been evaluated. Metal-free phthalocyanine films of good optical quality are processed in our laboratories by vapor deposition technique. Initial studies on these films indicate that they have excellent chemical, laser, and environmental stability. They have large nonlinear optical parameters and show intrinsic optical bistability. This bistability is essential for optical logic gates and optical switching applications. Waveguiding and device making investigations of these materials are underway.

  10. Optical and magneto-optical properties of metal phthalocyanine and metal porphyrin thin films.

    Science.gov (United States)

    Birnbaum, Tobias; Hahn, Torsten; Martin, Claudia; Kortus, Jens; Fronk, Michael; Lungwitz, Frank; Zahn, Dietrich R T; Salvan, Georgeta

    2014-03-12

    The optical constants together with the magneto-optical Voigt constants of several phthalocyanine (Pc) and methoxy functionalized tetraphenylporphyrin (TMPP) thin films prepared on silicon substrates are presented. The materials investigated are MePc with Me = Fe, Co, Ni, Cu, Zn and MeTMPP with Me = Cu, Ni. We also compared our results to the metal-free H2Pc, H2TPP and H2TMPP. The experimental results will be supported by electronic structure calculations based on density functional theory (DFT) and interpreted using the perimeter model initially proposed by Platt. The model allows for qualitative understanding of the forbidden character of transitions in planar, aromatic molecules, and is able to qualify differences between Pc and TMPP type materials.

  11. Optical properties of PMN-PT thin films prepared using pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Tong, X.L., E-mail: tongxinglin@yahoo.com.cn [Key Laboratory of Fiber Optic Sensing Technology and Information Processing, Wuhan University of Technology, Ministry of Education, 122 Luoshi Road, Wuhan 430070 (China); Lin, K.; Lv, D.J.; Yang, M.H.; Liu, Z.X.; Zhang, D.S. [Key Laboratory of Fiber Optic Sensing Technology and Information Processing, Wuhan University of Technology, Ministry of Education, 122 Luoshi Road, Wuhan 430070 (China)

    2009-06-30

    (1 - x)Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-xPbTiO{sub 3} (PMN-PT) thin films have been deposited on quartz substrates using pulsed laser deposition (PLD). Crystalline microstructure of the deposited PMN-PT thin films has been investigated with X-ray diffraction (XRD). Optical transmission spectroscopy and Raman spectroscopy are used to characterize optical properties of the deposited PMN-PT thin films. The results show that the PMN-PT thin films of perovskite structure have been formed, and the crystalline and optical properties of the PMN-PT thin films can be improved as increasing the annealing temperature to 750 deg. C, but further increasing the annealing temperature to 950 deg. C may lead to a degradation of the crystallinity and the optical properties of the PMN-PT thin films. In addition, a weak second harmonic intensity (SHG) has been observed for the PMN-PT thin film formed at the optimum annealing temperature of 750 deg. C according to Maker fringe method. All these suggest that the annealing temperature has significant effect on the structural and optical properties of the PMN-PT thin films.

  12. On the Nature and Extent of Optically Thin Marine low Clouds

    Science.gov (United States)

    Leahy, L. V.; Wood, R.; Charlson, R. J.; Hostetler, C. A.; Rogers, R. R.; Vaughan, M. A.; Winker, D. M.

    2012-01-01

    Macrophysical properties of optically thin marine low clouds over the nonpolar oceans (60 deg S-60 deg N) are measured using 2 years of full-resolution nighttime data from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP). Optically thin clouds, defined as the subset of marine low clouds that do not fully attenuate the lidar signal, comprise almost half of the low clouds over the marine domain. Regionally, the fraction of low clouds that are optically thin (f(sub thin,cld)) exhibits a strong inverse relationship with the low-cloud cover, with maxima in the tropical trades (f(sub thin,cld) greater than 0.8) and minima in regions of persistent marine stratocumulus and in midlatitudes (f(sub thin,cld) less than 0.3). Domain-wide, a power law fit describes the cloud length distribution, with exponent beta = 2.03 +/- 0.06 (+/-95% confidence interval). On average, the fraction of a cloud that is optically thin decreases from approximately 1 for clouds smaller than 2 km to less than 0.3 for clouds larger than 30 km. This relationship is found to be independent of region, so that geographical variations in the cloud length distribution explain three quarters of the variance in f(sub thin,cld). Comparing collocated trade cumulus observations from CALIOP and the airborne High Spectral Resolution Lidar reveals that clouds with lengths smaller than are resolvable with CALIOP contribute approximately half of the low clouds in the region sampled. A bounded cascade model is constructed to match the observations from the trades. The model shows that the observed optically thin cloud behavior is consistent with a power law scaling of cloud optical depth and suggests that most optically thin clouds only partially fill the CALIOP footprint.

  13. On the Nature and Extent of Optically Thin Marine low Clouds

    Science.gov (United States)

    Leahy, L. V.; Wood, R.; Charlson, R. J.; Hostetler, C. A.; Rogers, R. R.; Vaughan, M. A.; Winker, D. M.

    2012-01-01

    Macrophysical properties of optically thin marine low clouds over the nonpolar oceans (60 deg S-60 deg N) are measured using 2 years of full-resolution nighttime data from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP). Optically thin clouds, defined as the subset of marine low clouds that do not fully attenuate the lidar signal, comprise almost half of the low clouds over the marine domain. Regionally, the fraction of low clouds that are optically thin (f(sub thin,cld)) exhibits a strong inverse relationship with the low-cloud cover, with maxima in the tropical trades (f(sub thin,cld) greater than 0.8) and minima in regions of persistent marine stratocumulus and in midlatitudes (f(sub thin,cld) less than 0.3). Domain-wide, a power law fit describes the cloud length distribution, with exponent beta = 2.03 +/- 0.06 (+/-95% confidence interval). On average, the fraction of a cloud that is optically thin decreases from approximately 1 for clouds smaller than 2 km to less than 0.3 for clouds larger than 30 km. This relationship is found to be independent of region, so that geographical variations in the cloud length distribution explain three quarters of the variance in f(sub thin,cld). Comparing collocated trade cumulus observations from CALIOP and the airborne High Spectral Resolution Lidar reveals that clouds with lengths smaller than are resolvable with CALIOP contribute approximately half of the low clouds in the region sampled. A bounded cascade model is constructed to match the observations from the trades. The model shows that the observed optically thin cloud behavior is consistent with a power law scaling of cloud optical depth and suggests that most optically thin clouds only partially fill the CALIOP footprint.

  14. Optically transparent frequency selective surfaces on flexible thin plastic substrates

    Directory of Open Access Journals (Sweden)

    Aliya A. Dewani

    2015-02-01

    Full Text Available A novel 2D simple low cost frequency selective surface was screen printed on thin (0.21 mm, flexible transparent plastic substrate (relative permittivity 3.2. It was designed, fabricated and tested in the frequency range 10-20 GHz. The plane wave transmission and reflection coefficients agreed with numerical modelling. The effective permittivity and thickness of the backing sheet has a significant effect on the frequency characteristics. The stop band frequency reduced from 15GHz (no backing to 12.5GHz with polycarbonate. The plastic substrate thickness beyond 1.8mm has minimal effect on the resonant frequency. While the inner element spacing controls the stop-band frequency, the substrate thickness controls the bandwidth. The screen printing technique provided a simple, low cost FSS fabrication method to produce flexible, conformal, optically transparent and bio-degradable FSS structures which can find their use in electromagnetic shielding and filtering applications in radomes, reflector antennas, beam splitters and polarizers.

  15. Nonlinear optical susceptibility of multicomponent tellurite thin film glasses

    Science.gov (United States)

    Munoz-Martin, D.; Fernandez, H.; Fernandez-Navarro, J. M.; Gonzalo, J.; Solis, J.; Fierro, J. L. G.; Domingo, C.; Garcia-Ramos, J. V.

    2008-12-01

    Tellurite (TeO2-TiO2-Nb2O5) thin film glasses have been produced by pulsed laser deposition. The dispersion of the real and imaginary parts of the linear refractive index has been measured in the range from 300 to 1700 nm. Films present high refractive index (n =2.01) and reduced absorption (k nm. The nonlinear third order optical susceptibility (|χ(3)|) has been determined at four different wavelengths (600, 800, 1200, and 1500 nm). The out-of-resonance |χ(3)| values (˜10-12 esu) are found to be ten times higher than those of the bulk glass and 102 times higher than that of silica. Compositional and structural analysis reveals an increase of both the Ti atomic content and the fraction of nonbridging oxygen bonds in the deposited films. Both factors lead to a higher hyperpolarizability of the film constituents that is proposed to be responsible for the high |χ(3)| value of the films.

  16. Structural and nonlinear optical properties of as-grown and annealed metallophthalocyanine thin films

    Energy Technology Data Exchange (ETDEWEB)

    Zawadzka, A., E-mail: azawa@fizyka.umk.pl [Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Torun (Poland); Płóciennik, P.; Strzelecki, J. [Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Torun (Poland); Pranaitis, M.; Dabos-Seignon, S.; Sahraoui, B. [LUNAM Université, Université d' Angers, CNRS UMR 6200, Laboratoire MOLTECH-Anjou, 2 bd Lavoisier, 49045 Angers cedex (France)

    2013-10-31

    The paper presents the Third Harmonic Generation investigation of four metallophtalocyanine (MPc, M = Cu, Co, Mg and Zn) thin films. The investigated films were fabricated by Physical Vapor Deposition in high vacuum onto quartz substrates. MPc thin films were annealed after fabrication in ambient atmosphere for 12 h at the temperature equal to 150 °C or 250 °C. The Third Harmonic Generation spectra were measured to investigate the nonlinear optical properties and their dependence on the structure of the thin film after the annealing process. This approach allowed us to determine the electronic contribution of the third-order nonlinear optical susceptibility χ{sup <3>}{sub elec} of these MPc films and to investigate two theoretical models for explanation of the observed results. We find that the annealing process significantly changes the optical and structural properties of MPc thin films. - Highlights: • Metallophtalocyanine thin films were grown by Physical Vapor Deposition technique. • MPcs thin films were undergone an annealing process in ambient atmosphere. • Third Harmonic spectra were measured to investigate nonlinear optical properties. • The third order nonlinear optical susceptibility χ{sup <3>}{sub elec} was determined. • We report changing both nonlinear optical and structural properties of thin films.

  17. Magnetic and optical properties of the nickel thin film deposited by GLAD technique

    Directory of Open Access Journals (Sweden)

    Potočnik Jelena M.

    2014-01-01

    Full Text Available In this work, nickel thin film was deposited on glass sample using Glancing Angle Deposition (GLAD technique, to a thickness of 1 μm. Glass sample was positioned 15 degrees with respect to the nickel vapor flux. The nickel thin film was characterized by Atomic Force Microscopy (AFM, Magneto- Optical Kerr effect Microscopy and Spectroscopic Ellipsometry. According to an AFM cross-section imaging, it was found that the nickel thin film has a columnar structure. The values of the coercively, obtained from the magnetic hysteresis loops, were analyzed as a function of the sample rotation in the magnetic field. It was found that the direction of magnetization easy axis lies toward the structure growth. Optical properties of the nickel thin film were studied at the wavelength of 455 nm. From the shape of the refractive index and the extinction coefficient diagrams could be concluded that the nickel thin film has an optical anisotropy.

  18. Barrier Formation on a YBa2Cu3Oy Thin Film Using CF4 Plasma Fluorination

    Institute of Scientific and Technical Information of China (English)

    阿巴斯; 康琳; 许伟伟; 杨森祖; 吴培亨

    2002-01-01

    We investigate the surface structure and composition ofa YBa2Cu3Oy (YBCO) thin film modified by CF4 plasma fluorination. In addition to the absorption of hydrocarbons, chemical reactions of the YBCO surface take place during CF4 plasma treatment. Various x-ray photoelectron spectroscopic data are reported and discussed. The existence of a thin barrier is confirmed, which homogeneously covers the edge of the base YBCO film in our interface engineering Josephson junction. Measurements of Auger electron spectroscopic data and the resistance versus temperature indicate that the barrier is a controllable-insulating layer.

  19. Development of Dual-light Path Monitoring System of Optical Thin-film Thickness

    Institute of Scientific and Technical Information of China (English)

    XU Shi-jun

    2005-01-01

    The accurate monitoring of optical thin-film thickness is a key technique for depositing optical thin-film. For existing coating equipments, which are low precision and automation level on monitoring thin-film thickness, a new photoelectric control and analysis system has been developed. In the new system, main techniques include a photoelectric system with dual-light path, a dual-lock-phase circuit system and a comprehensive digital processing-control-analysis system.The test results of new system show that the static and dynamic stabilities and the control precision of thin-film thickness are extremely increased. The standard deviation of thin-film thickness, which indicates the duplication of thin-film thickness monitoring, is equal to or less than 0.72%. The display resolution limit on reflectivity is 0.02 %. In the system, the linearity of drift is very high, and the static drift ratio approaches zero.

  20. Structural and optical properties of Cd0.8Zn0.2S thin films

    Science.gov (United States)

    Xia, Di; Caijuan, Tian; Rongzhe, Tang; Wei, Li; Lianghuan, Feng; Jingquan, Zhang; Lili, Wu; Zhi, Lei

    2011-02-01

    Cd1-xZnxS thin films were deposited on glass substrates by a vacuum coevaporation method. The structural, compositional, and optical properties of as-deposited Cd0.8Zn0.2S films were investigated using X-ray diffraction (XRD), X-ray fluorescence (XRF), X-ray photoelectron spectroscopy (XPS), and optical transmittance spectrum. The thin films are hexagonal in structure, with strong preferential orientation along the (002) planes. The composition of Cd1-xZnxS thin films monitored by a quartz crystal oscillator agrees well with that obtained from XRF and XPS measurements. The optical constants, such as refractive index, single-oscillator energy, dispersion energy, absorption coefficients, and the optical band gap, were deduced by the Swanepoel's method, in combination with the Wemple and DiDomenico single-oscillator model, from the transmission spectrum of Cd0.8Zn0.2S thin films.

  1. Structural and optical properties of Cd0.8Zn0.2S thin films*

    Institute of Scientific and Technical Information of China (English)

    Di Xia; Tian Caijuan; Tang Rongzhe; Li Wei; Feng Lianghuan; Zhang Jingquan; Wu Lili; Lei Zhi

    2011-01-01

    Cd1-xZnxS thin films were deposited on glass substrates by a vacuum coevaporation method. The structural, compositional, and optical properties of as-deposited Cd0.8Zn0.2S films were investigated using X-ray diffraction (XRD), X-ray fluorescence (XRF), X-ray photoelectron spectroscopy (XPS), and optical transmittance spectrum. The thin films are hexagonal in structure, with strong preferential orientation along the (002) planes. The composition of Cd1-xZnxS thin films monitored by a quartz crystal oscillator agrees well with that obtained from XRF and XPS measurements. The optical constants, such as refractive index, single-oscillator energy, dispersion energy, absorption coefficients, and the optical band gap, were deduced by the Swanepoel's method, in combination with the Wemple and DiDomenico single-oscillator model, from the transmission spectrum of Cd0.8Zn0.2S thin films.

  2. Cell adhesion property of cathodic arc plasma deposited CrN thin film

    Science.gov (United States)

    Kim, Sun Kyu; Pham, Vuong Hung

    2009-09-01

    The interaction between human osteoblast cells and CrN thin film was studied in vitro. CrN thin films were produced by cathodic arc plasma deposition. The surface was characterized by atomic force microscopy. Cell adhesion on the coatings was assessed by MTT assay and visualization. Cell cytoskeleton organization was studied by analyzing microtubule and actin cytoskeleton organization. Focal contact adhesion was monitored by analyzing vinculin density. The study found that the CrN thin film is a potential candidate as a protective coating on implantable devices that require minimal cellular adhesion.

  3. Effect of surface microstructure and wettability on plasma protein adsorption to ZnO thin films prepared at different RF powers

    Energy Technology Data Exchange (ETDEWEB)

    Huang Zhanyun; Chen Min; Chen Dihu [State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-Sen University, Guangzhou 510275 (China); Pan Shirong, E-mail: stscdh@mail.sysu.edu.c [Artificial Heart Lab, the 1st Affiliate Hospital of Sun Yat-Sen University, Guangzhou 510080 (China)

    2010-10-01

    In this paper, the adsorption behavior of plasma proteins on the surface of ZnO thin films prepared by radio frequency (RF) sputtering under different sputtering powers was studied. The microstructures and surface properties of the ZnO thin films were investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible optical absorption spectroscopy and contact angle techniques. The results show that the ZnO thin films have better orientation of the (0 0 2) peak with increasing RF power, especially at around 160 W, and the optical band gap of the ZnO films varies from 3.2 to 3.4 eV. The contact angle test carried out by the sessile drop technique denoted a hydrophobic surface of the ZnO films, and the surface energy and adhesive work of the ZnO thin films decreased with increasing sputtering power. The amounts of human fibrinogen (HFG) and human serum albumin (HSA) adsorbing on the ZnO films and reference samples were determined by using enzyme-linked immunosorbent assay (ELISA). The results show that fewer plasma proteins and a smaller HFG/HSA ratio adsorb on the ZnO thin films' surface.

  4. Effect of surface microstructure and wettability on plasma protein adsorption to ZnO thin films prepared at different RF powers.

    Science.gov (United States)

    Huang, Zhan-Yun; Chen, Min; Pan, Shi-Rong; Chen, Di-Hu

    2010-10-01

    In this paper, the adsorption behavior of plasma proteins on the surface of ZnO thin films prepared by radio frequency (RF) sputtering under different sputtering powers was studied. The microstructures and surface properties of the ZnO thin films were investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible optical absorption spectroscopy and contact angle techniques. The results show that the ZnO thin films have better orientation of the (0 0 2) peak with increasing RF power, especially at around 160 W, and the optical band gap of the ZnO films varies from 3.2 to 3.4 eV. The contact angle test carried out by the sessile drop technique denoted a hydrophobic surface of the ZnO films, and the surface energy and adhesive work of the ZnO thin films decreased with increasing sputtering power. The amounts of human fibrinogen (HFG) and human serum albumin (HSA) adsorbing on the ZnO films and reference samples were determined by using enzyme-linked immunosorbent assay (ELISA). The results show that fewer plasma proteins and a smaller HFG/HSA ratio adsorb on the ZnO thin films' surface.

  5. Nonlinear optical parameters of nanocrystalline AZO thin film measured at different substrate temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Jilani, Asim, E-mail: asim.jilane@gmail.com [Centre of Nanotechnology, King Abdulaziz University, Jeddah (Saudi Arabia); Abdel-wahab, M.Sh [Centre of Nanotechnology, King Abdulaziz University, Jeddah (Saudi Arabia); Materials Science and Nanotechnology Department, Faculty of Postgraduate Studies for Advanced Sciences, Beni -Suef University, Beni-Suef (Egypt); Al-ghamdi, Attieh A. [Centre of Nanotechnology, King Abdulaziz University, Jeddah (Saudi Arabia); Dahlan, Ammar sadik [Department of architecture, faculty of environmental design, King Abdulaziz University, Jeddah (Saudi Arabia); Yahia, I.S. [Department of Physics, Faculty of Science, King Khalid University, P.O. Box 9004, Abha (Saudi Arabia); Nano-Science & Semiconductor Labs, Department of Physics, Faculty of Education, Ain Shams University, Roxy, 11757 Cairo (Egypt)

    2016-01-15

    The 2.2 wt% of aluminum (Al)-doped zinc oxide (AZO) transparent and preferential c-axis oriented thin films were prepared by using radio frequency (DC/RF) magnetron sputtering at different substrate temperature ranging from room temperature to 200 °C. For structural analysis, X-ray Diffraction (XRD) and Atomic Force Electron Microscope (AFM) was used for morphological studies. The optical parameters such as, optical energy gap, refractive index, extinction coefficient, dielectric loss, tangent loss, first and third order nonlinear optical properties of transparent films were investigated. High transmittance above 90% and highly homogeneous surface were observed in all samples. The substrate temperature plays an important role to get the best transparent conductive oxide thin films. The substrate temperature at 150 °C showed the growth of highly transparent AZO thin film. Energy gap increased with the increased in substrate temperature of Al doped thin films. Dielectric constant and loss were found to be photon energy dependent with substrate temperature. The change in substrate temperature of Al doped thin films also affect the non-liner optical properties of thin films. The value of χ{sup (3)} was found to be changed with the grain size of the thin films that directly affected by the substrate temperature of the pure and Al doped ZnO thin films.

  6. Moisture resistant and anti-reflection optical coatings produced by plasma polymerization of organic compounds

    Science.gov (United States)

    Hollahan, J. R.; Wydeven, T.

    1975-01-01

    The need for protective coatings on critical optical surfaces, such as halide crystal windows or lenses used in spectroscopy, has long been recognized. It has been demonstrated that thin, one micron, organic coatings produced by polymerization of flourinated monomers in low temperature gas discharge (plasma) exhibit very high degrees of moisture resistence, e.g., hundreds of hours protection for cesium iodide vs. minutes before degradation sets in for untreated surfaces. The index of refraction of these coatings is intermediate between that of the halide substrate and air, a condition for anti-reflection, another desirable property of optical coatings. Thus, the organic coatings not only offer protection, but improved transmittance as well. The polymer coating is non-absorbing over the range 0.4 to 40 microns with an exception at 8.0 microns, the expected absorption for C-F bonds.

  7. Optical and structural properties of CsI thin film photocathode

    OpenAIRE

    2014-01-01

    In the present work performance of cesium iodide thin film photocathode is studied in detail. The optical absorbance of cesium iodide thin films have been analyzed in the spectral range of 190 nm to 900 nm. The optical band gap energy of 500 nm thick cesium iodide film is calculated using Tauc plot from absorbance data. Refractive index is estimated from envelope plot of transmittance data using Swanepoel's method. Absolute quantum efficiency measurement has been carried out in the wavelength...

  8. Current Situation and Developing Trend of Optical Thin Films for DPSSL

    Institute of Scientific and Technical Information of China (English)

    BU Yi-kun; ZHENG Quan; MIAO Tong-qun; QIAN Long-sheng

    2005-01-01

    A series of optical thin films for LD pumped all-solid-state laser are discussed. Because of the difference between the pumped wavelength and the output wavelength, various kinds of pumping ways, resonator structures and laser crystals, there are so many new kinds of optical thin films, including novel edge filters ,high reflection and antireflection coatings. The key problems in designing and coating are analyzed, and the researches carried out worldwide in this field are also given.

  9. Optical properties of Au-dispersed ZrO2 thin films

    Science.gov (United States)

    Huang, Weimin; Arizpe-Chávez, Humberto; Ramírez-Bon, Rafael; Espinoza-Beltrán, Francisco

    2002-03-01

    The optical absorption of gold nanoparticles dispersed within mesoporous zirconia thin films has been investigated. The samples of this material were prepared by the sol-gel technique. TEM studies showed Au nanoparticles with sizes in the range from 5 to 20 nm, embedded into the zirconia matrix. Also, XR diffraction spectra showed Au diffraction peaks corresponding to metallic nanoparticles with sizes in the range 7-9 nm. The accepted surface plasma resonance value for gold is 556 nm. The absorption spectra showed a red shift on the SPR position for samples thermally annealed. Also, a red shift is observed for samples treated with monoethanolamine (MEA) vapor. A lowering in the intensities of the absorption peaks for the treated samples is observed. On the other hand, larger gold dopping produces a blue shift in the absorption spectra, with an increment in the intensity of the absorption peaks. The Tauc-Lorentz fitting model allowed us to measure changes in the dielectric function of the material. Therefore, we conclude that not only the particle size drives the optical absorption spectra in gold-doped films. The observed opposite results can be explained if we introduce changes in the dielectric constant of the films.

  10. Structure and Optical Properties of Silicon Nanocrystals Embedded in Amorphous Silicon Thin Films Obtained by PECVD

    Directory of Open Access Journals (Sweden)

    B. M. Monroy

    2011-01-01

    Full Text Available Silicon nanocrystals embedded in amorphous silicon matrix were obtained by plasma enhanced chemical vapor deposition using dichlorosilane as silicon precursor. The RF power and dichlorosilane to hydrogen flow rate ratio were varied to obtain different crystalline fractions and average sizes of silicon nanocrystals. High-resolution transmission electron microscopy images and RAMAN measurements confirmed the existence of nanocrystals embedded in the amorphous matrix with average sizes between 2 and 6 nm. Different crystalline fractions (from 12% to 54% can be achieved in these films by regulating the selected growth parameters. The global optical constants of the films were obtained by UV-visible transmittance measurements. Effective band gap variations from 1.78 to 2.3 eV were confirmed by Tauc plot method. Absorption coefficients higher than standard amorphous silicon were obtained in these thin films for specific growth parameters. The relationship between the optical properties is discussed in terms of the different internal nanostructures of the samples.

  11. Design, fabrication and optical characterization of photonic crystal assisted thin film monocrystalline-silicon solar cells.

    Science.gov (United States)

    Meng, Xianqin; Depauw, Valérie; Gomard, Guillaume; El Daif, Ounsi; Trompoukis, Christos; Drouard, Emmanuel; Jamois, Cécile; Fave, Alain; Dross, Frédéric; Gordon, Ivan; Seassal, Christian

    2012-07-02

    In this paper, we present the integration of an absorbing photonic crystal within a monocrystalline silicon thin film photovoltaic stack fabricated without epitaxy. Finite difference time domain optical simulations are performed in order to design one- and two-dimensional photonic crystals to assist crystalline silicon solar cells. The simulations show that the 1D and 2D patterned solar cell stacks would have an increased integrated absorption in the crystalline silicon layer would increase of respectively 38% and 50%, when compared to a similar but unpatterned stack, in the whole wavelength range between 300 nm and 1100 nm. In order to fabricate such patterned stacks, we developed an effective set of processes based on laser holographic lithography, reactive ion etching and inductively coupled plasma etching. Optical measurements performed on the patterned stacks highlight the significant absorption increase achieved in the whole wavelength range of interest, as expected by simulation. Moreover, we show that with this design, the angle of incidence has almost no influence on the absorption for angles as high as around 60°.

  12. Low temperature plasma deposition of silicon thin films: From amorphous to crystalline

    OpenAIRE

    Roca i Cabarrocas, Pere; Cariou, Romain; Labrune, Martin

    2012-01-01

    International audience; We report on the epitaxial growth of crystalline silicon films on (100) oriented crystalline silicon substrates by standard plasma enhanced chemical vapor deposition at 175 °C. Such unexpected epitaxial growth is discussed in the context of deposition processes of silicon thin films, based on silicon radicals and nanocrystals. Our results are supported by previous studies on plasma synthesis of silicon nanocrystals and point toward silicon nanocrystals being the most p...

  13. Staging optics considerations for a plasma wakefield acceleration linear collider

    Energy Technology Data Exchange (ETDEWEB)

    Lindstrøm, C.A., E-mail: c.a.lindstrom@fys.uio.no [Department of Physics, University of Oslo, Oslo 0316 (Norway); SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); Adli, E. [Department of Physics, University of Oslo, Oslo 0316 (Norway); SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); Allen, J.M.; Delahaye, J.P.; Hogan, M.J. [SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); Joshi, C. [Department of Electrical Engineering, UCLA, Los Angeles, CA 90095 (United States); Muggli, P. [Max Planck Institute for Physics, 80805 Munich (Germany); Raubenheimer, T.O.; Yakimenko, V. [SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States)

    2016-09-01

    Plasma wakefield acceleration offers acceleration gradients of several GeV/m, ideal for a next-generation linear collider. The beam optics requirements between plasma cells include injection and extraction of drive beams, matching the main beam beta functions into the next cell, canceling dispersion as well as constraining bunch lengthening and chromaticity. To maintain a high effective acceleration gradient, this must be accomplished in the shortest distance possible. A working example is presented, using novel methods to correct chromaticity, as well as scaling laws for a high energy regime.

  14. Optical Multi-hysteresises and "Rogue Waves" in Nonlinear Plasma

    CERN Document Server

    Kaplan, A E

    2010-01-01

    An overdense plasma layer irradiated by an intense light can exhibit dramatic nonlinear-optical effects due to a relativistic mass-effect of free electrons: highly-multiple hysteresises of reflection and transition, and emergence of gigantic "rogue waves". Those are trapped quasi-soliton field spikes inside the layer, sustained by an incident radiation with a tiny fraction of their peak intensity once they have been excited by orders of magnitude larger pumping. The phenomenon persists even in the layers with "soft" boundaries, as well as in a semi-infinite plasma with low absorption.

  15. Controlling multiple filaments by relativistic optical vortex beams in plasmas

    Science.gov (United States)

    Ju, L. B.; Huang, T. W.; Xiao, K. D.; Wu, G. Z.; Yang, S. L.; Li, R.; Yang, Y. C.; Long, T. Y.; Zhang, H.; Wu, S. Z.; Qiao, B.; Ruan, S. C.; Zhou, C. T.

    2016-09-01

    Filamentation dynamics of relativistic optical vortex beams (OVBs) propagating in underdense plasma is investigated. It is shown that OVBs with finite orbital angular momentum (OAM) exhibit much more robust propagation behavior than the standard Gaussian beam. In fact, the growth rate of the azimuthal modulational instability decreases rapidly with increase of the OVB topological charge. Thus, relativistic OVBs can maintain their profiles for significantly longer distances in an underdense plasma before filamentation occurs. It is also found that an OVB would then break up into regular filament patterns due to conservation of the OAM, in contrast to a Gaussian laser beam, which in general experiences random filamentation.

  16. Charge trapping in plasma-polymerized thin films

    Science.gov (United States)

    Klemberg-Sapieha, J. E.; Sapieha, S.; Wertheimer, M. R.; Yelon, A.

    1980-07-01

    The surface potential of freshly plasma-polymerized films of hexamethyldisiloxane was measured for film thicknesses ranging from about 0.1 to 1 micron. The films are found to be in an electret state under certain fabrication conditions. Experimental evidence is given which indicates that charge trapped during plasma polymerization is uniformly distributed across the sample thickness. It has been found that other electret properties such as the polarity of trapped charge, and the charge retention characteristics can also be controlled by an appropriate choice of polymerization conditions.

  17. The use of a genetic algorithm in optical thin film design and optimisation

    Directory of Open Access Journals (Sweden)

    Efrem K. Ejigu

    2010-07-01

    Full Text Available We used a genetic algorithm in the design and optimisation of optical thin films and present the effects of the choice of variables, refractive index and optical thickness, in both applications of this algorithm, in this paper. The Fourier transform optical thin film design method was used to create a starting population, which was later optimised by the genetic algorithm. In the genetic algorithm design application, the effect of the choice of variable was not distinct, as it depended on the type of design specification. In the genetic algorithm optimisation application, the choice of refractive index as a variable showed a better performance than that of optical thickness. The results of this study indicate that a genetic algorithm is more effective in the design application than in the optimisation application of optical thin film synthesis.

  18. Characterization of Optical and Electrical Properties of Transparent Conductive Boron-Doped Diamond thin Films Grown on Fused Silica

    Directory of Open Access Journals (Sweden)

    Bogdanowicz Robert

    2014-12-01

    Full Text Available Abstract A conductive boron-doped diamond (BDD grown on a fused silica/quartz has been investigated. Diamond thin films were deposited by the microwave plasma enhanced chemical vapor deposition (MW PECVD. The main parameters of the BDD synthesis, i.e. the methane admixture and the substrate temperature were investigated in detail. Preliminary studies of optical properties were performed to qualify an optimal CVD synthesis and film parameters for optical sensing applications. The SEM micro-images showed the homogenous, continuous and polycrystalline surface morphology; the mean grain size was within the range of 100-250 nm. The fabricated conductive boron-doped diamond thin films displayed the resistivity below 500 mOhm cm-1 and the transmittance over 50% in the VIS-NIR wavelength range. The studies of optical constants were performed using the spectroscopic ellipsometry for the wavelength range between 260 and 820 nm. A detailed error analysis of the ellipsometric system and optical modelling estimation has been provided. The refractive index values at the 550 nm wavelength were high and varied between 2.24 and 2.35 depending on the percentage content of methane and the temperature of deposition.

  19. Novel optical super-resolution pattern with upright edges diffracted by a tiny thin aperture.

    Science.gov (United States)

    Wu, Jiu Hui; Zhou, Kejiang

    2015-08-24

    In the past decade numerous efforts have been concentrated to achieve optical imaging resolution beyond the diffraction limit. In this letter a thin microcavity theory of near-field optics is proposed by using the power flow theorem firstly. According to this theory, the near-field optical diffraction from a tiny aperture whose diameter is less than one-tenth incident wavelength embedded in a thin conducting film is investigated by considering this tiny aperture as a thin nanocavity. It is very surprising that there exists a kind of novel super-resolution diffraction patterns showing resolution better than λ/80 (λ is the incident wavelength), which is revealed for the first time to our knowledge in this letter. The mechanism that has allowed the imaging with this kind of super-resolution patterns is due to the interaction between the incident wave and the thin nanocavity with a complex wavenumber. More precisely, these super-resolution patterns with discontinuous upright peaks are formed by one or three items of the integration series about the cylindrical waves according to our simulation results. This novel optical super-resolution with upright edges by using the thin microcavity theory presented in the study could have potential applications in the future semiconductor lithography process, nano-size laser-drilling technology, microscopy, optical storage, optical switch, and optical information processing.

  20. Nonlinear optical properties of a self-organized dye thin film

    Institute of Scientific and Technical Information of China (English)

    Haifeng Kang; Yizhong Yuan; Zhenrong Sun; Zugeng Wang

    2007-01-01

    @@ A self-organized thin film of a cyanine dye is fabricated by the spin-coating technique and is characterized by ultraviolet-visible spectroscopy, infrared (IR) spectroscopy, small-angle X-ray diffraction, ellipsometer,and atomic force microscopy (AFM). The nonlinear optical properties of the thin films are investigated by degenerate four wave mixing (DFWM) technique. The cyanine dye thin film sample exhibits high optical nonlinearities (χ(3) = 2.55 × 10-12 esu), and the mechanism is analyzed by the exciton coupling theory.

  1. Raman spectroscopy of optical properties in CdS thin films

    Directory of Open Access Journals (Sweden)

    Trajić J.

    2015-01-01

    Full Text Available Properties of CdS thin films were investigated applying atomic force microscopy (AFM and Raman spectroscopy. CdS thin films were prepared by using thermal evaporation technique under base pressure 2 x 10-5 torr. The quality of these films was investigated by AFM spectroscopy. We apply Raman scattering to investigate optical properties of CdS thin films, and reveal existence of surface optical phonon (SOP mode at 297 cm-1. Effective permittivity of mixture were modeled by Maxwell - Garnet approximation. [Projekat Ministarstva nauke Republike Srbije, br. 45003

  2. Method of preparing water purification membranes. [polymerization of allyl amine as thin films in plasma discharge

    Science.gov (United States)

    Hollahan, J. R.; Wydeven, T. J., Jr. (Inventor)

    1974-01-01

    Allyl amine and chemically related compounds are polymerized as thin films in the presence of a plasma discharge. The monomer compound can be polymerized by itself or in the presence of an additive gas to promote polymerization and act as a carrier. The polymerized films thus produced show outstanding advantages when used as reverse osmosis membranes.

  3. Plasma breaking of thin films into nano-sized catalysts for carbon nanotube synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Gao, J.S.; Umeda, K.; Uchino, K.; Nakashima, H.; Muraoka, K

    2003-07-15

    Iron thin films deposited by pulse laser deposition (PLD) were broken into uniform nano-sized catalysts by plasma bombardment for carbon nanotube (CNT) synthesis. Size distributions of broken catalysts were obtained in terms of plasma discharge conditions. Vertically arranged high-density (10{sup 13} per m{sup 2}) CNTs were synthesized using microwave plasma chemical vapor deposition (MP-CVD) system and the gas mixture of N{sub 2} and CH{sub 4} on optimally broken catalysts with few carbonaceous particles on a large area Si substrate. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy (RS) were used to evaluate the obtained CNTs.

  4. Effects of Al Concentration on Structural and Optical Properties of Al-doped ZnO Thin Films

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min Su; Yim, Kwang Gug; Leem, Jae Young [Inje University, Gimhae (Korea, Republic of); Son, Jeong Sik [Kyungwoon University, Gumi (Korea, Republic of)

    2012-04-15

    Aluminium (Al)-doped zinc oxide (AZO) thin films with different Al concentrations were prepared by the solgel spin-coating method. Optical parameters such as the optical band gap, absorption coefficient, refractive index, dispersion parameter, and optical conductivity were studied in order to investigate the effects of the Al concentration on the optical properties of AZO thin films. The dispersion energy, single-oscillator energy, average oscillator wavelength, average oscillator strength, and refractive index at infinite wavelength of the AZO thin films were found to be affected by Al incorporation. The optical conductivity of the AZO thin films also increases with increasing photon energy

  5. Improvement of optical properties of TiO2 thin film treated with electron beam.

    Science.gov (United States)

    Shin, Joong-Hyeok; Lee, Byung Cheol; Woo, Hee-Gweon; Hwang, Kwang Ha; Jun, Jin

    2013-03-01

    Nanocrystalline titanium dioxide (TiO2) thin films on silicon wafer substrates were prepared by sol-gel spin coating process. The prepared thin films were treated with electron beam (1.1 MeV, 300 kGy) at air atmosphere. The effects of electron-beam (EB) irradiation on the structural and optical properties of the TiO2 thin films were investigated. The structures of all the TiO2 thin films by XRD analysis showed an anatase phase, and the phase remained unchanged within the investigating range of EB treatment. The thickness of the titania thin film decreased slightly with EB treatment whereas the porosity increased. The EB treatment of TiO2 thin film can increase the proportion of Ti3+ in Ti2p at the thin film surface. The optical transmittance of the film in the wavelength ranges of above 380 nm increased after the EB treatment while its refractive index decreased with increasing EB dose. Therefore, improvement of the optical properties could be due to the change in both surface chemistry and morphology of the TiO2 thin films affected by EB irradiation.

  6. Effect of gamma radiation on optical and electrical properties of tellurium dioxide thin films

    Indian Academy of Sciences (India)

    T K Maity; S L Sharma

    2008-11-01

    Gamma radiation induced changes in the optical and electrical properties of tellurium dioxide (TeO2) thin films, prepared by thermal evaporation, have been studied in detail. The optical characterization of the as-deposited thin films and that of the thin films exposed to various levels of gamma radiation dose clearly show that the optical bandgap decreases with increase in the gamma radiation dose up to a certain dose. At gamma radiation doses above this value, however, the optical bandgap has been found to increase. On the other hand, the current vs voltage plots for the as-deposited thin films and those for the thin films exposed to various levels of gamma radiation dose show that the current increases with the gamma radiation dose up to a certain dose and that the value of this particular dose depends upon the thickness of the film. The current has, however, been found to decrease with further increase in gamma radiation dose. The observed changes in both the optical and electrical properties indicate that TeO2 thin films can be used as the real time gamma radiation dosimeter up to a certain dose, a quantity that depends upon the thickness of the film.

  7. Influence of Electron Irradiation on Optical Properties of ZnSe Thin Films

    Directory of Open Access Journals (Sweden)

    P. Raghu

    2014-11-01

    Full Text Available Zinc Selenide (ZnSe thin films of 500 nm thickness were deposited by electron beam evaporation technique and irradiated with 8 MeV electron beam for the doses ranging from 0 Gy to 1 kGy. Optical properties were studied for both irradiated and pristine samples using Ultraviolet-Visible spectrophotometer. The increase in electron dose tends to decrease in transmittance and increase in refractive index of thin film. Irradiated thin film exhibits minimum of 67 % transmittance for 800 Gy with very high absorption of optical energy at 550 nm wavelength. The samples irradiated > 800 Gy tends to redeem the pristine properties. Optical band gap for irradiated thin film were direct and in the range of 2.66 – 2.69 eV.

  8. Optical characteristics of transparent samarium oxide thin films deposited by the radio-frequency sputtering technique

    Indian Academy of Sciences (India)

    A A ATTA; M M EL-NAHASS; KHALED M ELSABAWY; M M ABD EL-RAHEEM; A M HASSANIEN; A ALHUTHALI; ALI BADAWI; AMAR MERAZGA

    2016-11-01

    Transparent metal oxide thin films of samarium oxide (Sm$_2$O$_3$) were prepared on pre-cleaned fused optically flat quartz substrates by radio-frequency (RF) sputtering technique. The as-deposited thin films were annealed at different temperatures (873, 973 and 1073 K) for 4 h in air under normal atmospheric pressure. The topological morphology of the film surface was characterized by using atomic force microscopy (AFM). The optical properties of the as-prepared and annealed thin films were studied using their reflectance and transmittance spectra at nearly normal incident light. The estimated direct optical band gap energy (E$^{d}_{g}$ ) values were found to increase by increasing the annealing temperatures. The dispersion curves of the refractive index of Sm$_2$O$_3$ thin films were found to obey the single oscillator model.

  9. Chemically deposited Sb{sub 2}S{sub 3} thin films for optical recording

    Energy Technology Data Exchange (ETDEWEB)

    Shaji, S; Arato, A; Castillo, G Alan; Palma, M I Mendivil; Roy, T K Das; Krishnan, B [Facultad de IngenierIa Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon, C.P- 66450 (Mexico); O' Brien, J J; Liu, J, E-mail: bkrishnan@fime.uanl.m [Center for Nanoscience and Department of Chemistry and Biochemistry, University of Missouri-St. Louis, One Univ. Blvd., St. Louis, MO - 63121 (United States)

    2010-02-24

    Laser induced changes in the properties of Sb{sub 2}S{sub 3} thin films prepared by chemical bath deposition are described in this paper. Sb{sub 2}S{sub 3} thin films of thickness 550 nm were deposited from a solution containing SbCl{sub 3} and Na{sub 2}S{sub 2}O{sub 3} at 27 {sup 0}C for 5 h. These thin films were irradiated by a 532 nm continuous wave laser beam under different conditions at ambient atmosphere. X-ray diffraction analysis showed amorphous to polycrystalline transformation due to laser exposure of these thin films. Morphology and composition of these films were described. Optical properties of these films before and after laser irradiation were analysed. The optical band gap of the material was decreased due to laser induced crystallization. The results obtained confirm that there is further scope for developing this material as an optical recording media.

  10. Analytical model of optical field distribution of thin disk laser with thermal-optical aberration gain medium

    Science.gov (United States)

    Zhu, Guangzhi; Qiu, Yuli; Wang, Zexiong; Zhu, Xiao; Zhu, Changhong

    2016-08-01

    An analytical model is developed to analyze the optical field distribution of thin disk laser with a thermal-optical aberration gain medium. The fundamental mode field distribution is calculated by using the eigenvector method of the resonator transit matrix for different pumping parameters. The analytical results show that the uniformity of the pumping spot is an important factor that impacts the beam quality of thin disk laser. The uniform pumping spot is beneficial to decrease thermal aberration and Optical Path Difference (OPD) of thin disk crystal, and to improve the beam quality. However, the beam quality still decreases slightly with the increasing of pumping intensity under the uniform pumping condition. The main reason for degradation of beam quality is the aspherical part of OPD which leads to diffraction losses of the resonator and wavefront deformation.

  11. Bombardment of Thin Lithium Films with Energetic Plasma Flows

    Science.gov (United States)

    Gray, Travis Kelly

    2009-01-01

    The Divertor Erosion and Vapor Shielding Experiment (DEVEX) has been constructed in the Center for Plasma-Material Interactions at the University of Illinois at Urbana-Champaign. It consists of a conical theta-pinch connected to a 60 kV, 36 [mu]F capacitor bank which is switched with a rise time of 3.5 [mu]s. This results in a peak current of 300…

  12. Development of plasma bolometers using fiber-optic temperature sensors

    Science.gov (United States)

    Reinke, M. L.; Han, M.; Liu, G.; van Eden, G. G.; Evenblij, R.; Haverdings, M.; Stratton, B. C.

    2016-11-01

    Measurements of radiated power in magnetically confined plasmas are important for exhaust studies in present experiments and expected to be a critical diagnostic for future fusion reactors. Resistive bolometer sensors have long been utilized in tokamaks and helical devices but suffer from electromagnetic interference (EMI). Results are shown from initial testing of a new bolometer concept based on fiber-optic temperature sensor technology. A small, 80 μm diameter, 200 μm long silicon pillar attached to the end of a single mode fiber-optic cable acts as a Fabry-Pérot cavity when broadband light, λo ˜ 1550 nm, is transmitted along the fiber. Changes in temperature alter the optical path length of the cavity primarily through the thermo-optic effect, resulting in a shift of fringes reflected from the pillar detected using an I-MON 512 OEM spectrometer. While initially designed for use in liquids, this sensor has ideal properties for use as a plasma bolometer: a time constant, in air, of ˜150 ms, strong absorption in the spectral range of plasma emission, immunity to local EMI, and the ability to measure changes in temperature remotely. Its compact design offers unique opportunities for integration into the vacuum environment in places unsuitable for a resistive bolometer. Using a variable focus 5 mW, 405 nm, modulating laser, the signal to noise ratio versus power density of various bolometer technologies are directly compared, estimating the noise equivalent power density (NEPD). Present tests show the fiber-optic bolometer to have NEPD of 5-10 W/m2 when compared to those of the resistive bolometer which can achieve coatings, along with improving the spectral resolution of the interrogator.

  13. Towards Enhanced Performance Thin-film Composite Membranes via Surface Plasma Modification

    Science.gov (United States)

    Reis, Rackel; Dumée, Ludovic F.; Tardy, Blaise L.; Dagastine, Raymond; Orbell, John D.; Schutz, Jürg A.; Duke, Mikel C.

    2016-07-01

    Advancing the design of thin-film composite membrane surfaces is one of the most promising pathways to deal with treating varying water qualities and increase their long-term stability and permeability. Although plasma technologies have been explored for surface modification of bulk micro and ultrafiltration membrane materials, the modification of thin film composite membranes is yet to be systematically investigated. Here, the performance of commercial thin-film composite desalination membranes has been significantly enhanced by rapid and facile, low pressure, argon plasma activation. Pressure driven water desalination tests showed that at low power density, flux was improved by 22% without compromising salt rejection. Various plasma durations and excitation powers have been systematically evaluated to assess the impact of plasma glow reactions on the physico-chemical properties of these materials associated with permeability. With increasing power density, plasma treatment enhanced the hydrophilicity of the surfaces, where water contact angles decreasing by 70% were strongly correlated with increased negative charge and smooth uniform surface morphology. These results highlight a versatile chemical modification technique for post-treatment of commercial membrane products that provides uniform morphology and chemically altered surface properties.

  14. Polymorphous silicon thin films produced in dusty plasmas: application to solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Roca i Cabarrocas, Pere; Chaabane, N; Kharchenko, A V; Tchakarov, S [Laboratoire de Physique des Interfaces et des Couches Minces (UMR 7647), Ecole Polytechnique, 91128 Palaiseau Cedex (France)

    2004-12-01

    We summarize our current understanding of the optimization of PIN solar cells produced by plasma enhanced chemical vapour deposition from silane-hydrogen mixtures. To increase the deposition rate, the discharge is operated under plasma conditions close to powder formation, where silicon nanocrystals contribute to the deposition of so-called polymorphous silicon thin films. We show that the increase in deposition rate can be achieved via an accurate control of the plasma parameters. However, this also results in a highly defective interface in the solar cells due to the bombardment of the P-layer by positively charged nanocrystals during the deposition of the I-layer. We show that decreasing the ion energy by increasing the total pressure or by using silane-helium mixtures allows us to increase both the deposition rate and the solar cells efficiency, as required for cost effective thin film photovoltaics.

  15. Polymorphous silicon thin films produced in dusty plasmas: application to solar cells

    Science.gov (United States)

    Cabarrocas, Pere Roca i.; Chaâbane, N.; Kharchenko, A. V.; Tchakarov, S.

    2004-12-01

    We summarize our current understanding of the optimization of PIN solar cells produced by plasma enhanced chemical vapour deposition from silane hydrogen mixtures. To increase the deposition rate, the discharge is operated under plasma conditions close to powder formation, where silicon nanocrystals contribute to the deposition of so-called polymorphous silicon thin films. We show that the increase in deposition rate can be achieved via an accurate control of the plasma parameters. However, this also results in a highly defective interface in the solar cells due to the bombardment of the P-layer by positively charged nanocrystals during the deposition of the I-layer. We show that decreasing the ion energy by increasing the total pressure or by using silane helium mixtures allows us to increase both the deposition rate and the solar cells efficiency, as required for cost effective thin film photovoltaics.

  16. A thin transition film formed by plasma exposure contributes to the germanium surface hydrophilicity

    Science.gov (United States)

    Shumei, Lai; Danfeng, Mao; Zhiwei, Huang; Yihong, Xu; Songyan, Chen; Cheng, Li; Wei, Huang; Dingliang, Tang

    2016-09-01

    Plasma treatment and 10% NH4OH solution rinsing were performed on a germanium (Ge) surface. It was found that the Ge surface hydrophilicity after O2 and Ar plasma exposure was stronger than that of samples subjected to N2 plasma exposure. This is because the thin GeO x film formed on Ge by O2 or Ar plasma is more hydrophilic than GeO x N y formed by N2 plasma treatment. A flat (RMS direct wafer bonding. Project supported by the Key Project of Natural Science Foundation of China (No. 61534005), the National Science Foundation of China (No. 61474081), the National Basic Research Program of China (No. 2013CB632103), the Natural Science Foundation of Fujian Province (No. 2015D020), and the Science and Technology Project of Xiamen City (No. 3502Z20154091).

  17. Optical band gap tuning of Sb-Se thin films for xerographic based applications

    Science.gov (United States)

    Kaur, Ramandeep; Singh, Palwinder; Singh, Kulwinder; Kumar, Akshay; Thakur, Anup

    2016-10-01

    In the present paper we have studied the effect of Sb addition on the optical band gap tuning of thermally evaporated SbxSe100-x (x = 0, 5, 20, 50 and 60) thin films. The structural investigations revealed that all thin films were amorphous in nature. Transmission spectrum was taken in the range 400-2500 nm shows that all films are highly transparent in the near infrared region. The fundamental absorption edge shifts towards longer wavelength with Sb incorporation. The optical band gap decreases with addition of antimony in a-Se thin films. A good correlation has been drawn between experimentally estimated and theoretically calculated optical band gap. The decrease in optical band gap of thin films has been explained using chemical bond approach and density of states model. Decrease in optical band gap with Sb addition increases the concentration of electron deep traps which increases the X-ray sensitivity of Sb-Se thin films. Thus by tuning the optical band gap of Sb-Se alloy, it could be utilized for xerographic based applications.

  18. Prism coupling technique investigation of elasto-optical properties of thin polymer films

    Science.gov (United States)

    Ay, Feridun; Kocabas, Askin; Kocabas, Coskun; Aydinli, Atilla; Agan, Sedat

    2004-12-01

    The use of thin polymer films in optical planar integrated optical circuits is rapidly increasing. Much interest, therefore, has been devoted to characterizing the optical and mechanical properties of thin polymer films. This study focuses on measuring the elasto-optical properties of three different polymers; polystyrene, polymethyl-methacrylate, and benzocyclobutane. The out-of-plane elastic modulus, refractive index, film thickness, and birefringence of thin polymer films were determined by means of the prism coupling technique. The effect of the applied stress on the refractive index and birefringence of the films was investigated. Three-dimensional finite element method analysis was used so as to obtain the principal stresses for each polymer system, and combining them with the stress dependent refractive index measurements, the elasto-optic coefficients of the polymer films were determined. It was found that the applied stress in the out-of-plane direction of the thin films investigated leads to negative elasto-optic coefficients, as observed for all the three thin polymer films.

  19. Optical Gratings Coated with Thin Si3N4 Layer for Efficient Immunosensing by Optical Waveguide Lightmode Spectroscopy

    Directory of Open Access Journals (Sweden)

    Lorena Diéguez

    2012-04-01

    Full Text Available New silicon nitride coated optical gratings were tested by means of Optical Waveguide Lightmode Spectroscopy (OWLS. A thin layer of 10 nm of transparent silicon nitride was deposited on commercial optical gratings by means of sputtering. The quality of the layer was tested by x-ray photoelectron spectroscopy and atomic force microscopy. As a proof of concept, the sensors were successfully tested with OWLS by monitoring the concentration dependence on the detection of an antibody-protein pair. The potential of the Si3N4 as functional layer in a real-time biosensor opens new ways for the integration of optical waveguides with microelectronics.

  20. Influence of sputtering power on the optical properties of ITO thin films

    Energy Technology Data Exchange (ETDEWEB)

    K, Aijo John; M, Deepak, E-mail: manju.thankamoni@gmail.com; T, Manju, E-mail: manju.thankamoni@gmail.com [Department of Physics, Sree Sankara College, Kalady P. O., Ernakulam Dist., Kerala (India); Kumar, Vineetha V. [Dept. of Physics, K. E. College, Mannanam, Kottayam Dist., Kerala (India)

    2014-10-15

    Tin doped indium oxide films are widely used in transparent conducting coatings such as flat panel displays, crystal displays and in optical devices such as solar cells and organic light emitting diodes due to the high electrical resistivity and optical transparency in the visible region of solar spectrum. The deposition parameters have a commendable influence on the optical and electrical properties of the thin films. In this study, ITO thin films were prepared by RF magnetron sputtering. The properties of the films prepared under varying sputtering power were compared using UV- visible spectrophotometry. Effect of sputtering power on the energy band gap, absorption coefficient and refractive index are investigated.

  1. Optical properties of d.c. magneto sputtered tantalum and titanium nanostructure thin film metal hydrides

    Indian Academy of Sciences (India)

    M Singh; S Srivastava; S Agarwal; S Kumar; Y K Vijay

    2010-10-01

    Nanostructured thin films of tantalum and titanium were deposited on glass substrate using d.c. magnetron sputtering technique under the argon gas environment at a pressure of 0.1 mbar. Optical transmission and absorption studies were carried out for these samples with pressure of hydrogen. Large changes in both transmission and absorption on loading these films with hydrogen are accompanied by significant phase changes and electronic transformation. Optical photograph shows the colour variation after hydrogenation in case of tantalum film which may be used as decorative mirrors and hydrogen sensors. The hydrogen storage capability of thin films was confirmed by variation in optical properties.

  2. Influence of sputtering power on the optical properties of ITO thin films

    Science.gov (United States)

    K, Aijo John; Kumar, Vineetha V.; M, Deepak; T, Manju

    2014-10-01

    Tin doped indium oxide films are widely used in transparent conducting coatings such as flat panel displays, crystal displays and in optical devices such as solar cells and organic light emitting diodes due to the high electrical resistivity and optical transparency in the visible region of solar spectrum. The deposition parameters have a commendable influence on the optical and electrical properties of the thin films. In this study, ITO thin films were prepared by RF magnetron sputtering. The properties of the films prepared under varying sputtering power were compared using UV- visible spectrophotometry. Effect of sputtering power on the energy band gap, absorption coefficient and refractive index are investigated.

  3. Imaging Functions of Quasi-Periodic Nanohole Array as an Ultra-Thin Planar Optical Lens

    Directory of Open Access Journals (Sweden)

    Tsung Sheng Kao

    2015-06-01

    Full Text Available In this paper, the lensing functions and imaging abilities of a quasi-periodic nanohole array in a metal screen have been theoretically investigated and demonstrated. Such an optical binary mask with nanoholes designed in an aperiodic arrangement can function as an ultra-thin planar optical lens, imaging complex structures composed of multiple light sources at tens of wavelengths away from the lens surface. Via resolving two adjacent testing objects at different separations, the effective numerical aperture (N.A. and the effective imaging area of the planar optical lens can be evaluated, mimicking the imaging function of a conventional lens with high N.A. Furthermore, by using the quasi-periodic nanohole array as an ultra-thin planar optical lens, important applications such as X-ray imaging and nano-optical circuits may be found in circumstances where conventional optical lenses cannot readily be applied.

  4. Hydrogen influence on the electrical and optical properties of ZnO thin films grown under different atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Lorite, I., E-mail: lorite@physik.uni-leipzig; Wasik, J.; Michalsky, T.; Schmidt-Grund, R.; Esquinazi, P.

    2014-04-01

    In this work we studied the changes of the electrical and optical properties after hydrogen plasma treatment of polycrystalline ZnO thin films grown under different atmosphere conditions. The obtained results show that the gas used during the growth process plays an important role in the way hydrogen is incorporated in the films. The hydrogen doping can produce radiative and non-radiative defects that reduce the UV emission in ZnO films grown in oxygen atmosphere but it passivates defects created when the films are grown in nitrogen atmosphere. Impedance spectroscopy measurements show that these effects are related to regions where hydrogen is mostly located, either at the grain cores or boundaries. We discuss how hydrogen strongly influences the initial semiconducting behavior of the ZnO thin films. - Highlights: • Effectiveness of hydrogen treatment depends on the thin film growth conditions. • There is no detection of secondary phases after treatment by IS. • Hydrogen incorporation changes optical and electrical ZnO properties.

  5. Super-resolution optical microscopy of lipid plasma membrane dynamics.

    Science.gov (United States)

    Eggeling, Christian

    2015-01-01

    Plasma membrane dynamics are an important ruler of cellular activity, particularly through the interaction and diffusion dynamics of membrane-embedded proteins and lipids. FCS (fluorescence correlation spectroscopy) on an optical (confocal) microscope is a popular tool for investigating such dynamics. Unfortunately, its full applicability is constrained by the limited spatial resolution of a conventional optical microscope. The present chapter depicts the combination of optical super-resolution STED (stimulated emission depletion) microscopy with FCS, and why it is an important tool for investigating molecular membrane dynamics in living cells. Compared with conventional FCS, the STED-FCS approach demonstrates an improved possibility to distinguish free from anomalous molecular diffusion, and thus to give new insights into lipid-protein interactions and the traditional lipid 'raft' theory.

  6. Tailoring the optical bandgap and magnetization of cobalt ferrite thin films through controlled zinc doping

    Directory of Open Access Journals (Sweden)

    Deepanshu Sharma

    2016-08-01

    Full Text Available In this report, the tuning of the optical bandgap and saturation magnetization of cobalt ferrite (CFO thin films through low doping of zinc (Zn has been demonstrated. The Zn doped CFO thin films with doping concentrations (0 to 10% have been synthesized by ultrasonic assisted chemical vapour deposition technique. The optical bandgap varies from 1.48 to 1.88 eV and saturation magnetization varies from 142 to 221 emu/cc with the increase in the doping concentration and this change in the optical and magnetic properties is attributed to the change in the relative population of the Co2+ at the tetrahedral and octahedral sites. Raman study confirms the decrease in the population of Co2+ at tetrahedral sites with controlled Zn doping in CFO thin films. A quantitative analysis has been presented to explain the observed variation in the optical bandgap and saturation magnetization.

  7. Characteristics of ITO films with oxygen plasma treatment for thin film solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yong Seob [Department of Photoelectronics Information, Chosun College of Science and Technology, Gwangju (Korea, Republic of); Kim, Eungkwon [Digital Broadcasting Examination, Korean Intellectual Property Office, Daejeon, Suwon 440-746 (Korea, Republic of); Hong, Byungyou [School of Electronic and Electrical Engineering, Sungkyunkwan University, Cheoncheon-dong, 300, Jangan-gu, Suwon 440-746 (Korea, Republic of); Lee, Jaehyoeng, E-mail: jaehyeong@skku.edu [School of Electronic and Electrical Engineering, Sungkyunkwan University, Cheoncheon-dong, 300, Jangan-gu, Suwon 440-746 (Korea, Republic of)

    2013-12-15

    Graphical abstract: The effect of O{sub 2} plasma treatment on the surface and the work function of ITO films. - Highlights: • ITO films were prepared on the glass substrate by RF magnetron sputtering method. • Effects of O{sub 2} plasma treatment on the properties of ITO films were investigated. • The work function of ITO film was changed from 4.67 to 5.66 eV by plasma treatment. - Abstract: The influence of oxygen plasma treatment on the electro-optical and structural properties of indium-tin-oxide films deposited by radio frequency magnetron sputtering method were investigated. The films were exposed at different O{sub 2} plasma powers and for various durations by using the plasma enhanced chemical vapor deposition (PECVD) system. The resistivity of the ITO films was almost constant, regardless of the plasma treatment conditions. Although the optical transmittance of ITO films was little changed by the plasma power, the prolonged treatment slightly increased the transmittance. The work function of ITO film was changed from 4.67 eV to 5.66 eV at the plasma treatment conditions of 300 W and 60 min.

  8. Infrared-optical spectroscopy of transparent conducting perovskite (La,Ba)SnO{sub 3} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Dongmin; Yu, Kwangnam; Jun Chang, Young; Choi, E. J., E-mail: echoi@uos.ac.kr [Department of Physics, University of Seoul, Seoul 130-743 (Korea, Republic of); Sohn, Egon; Hoon Kim, Kee [Center for Novel States of Complex Materials Research, Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of)

    2014-01-13

    We have performed optical transmission, reflection, spectroscopic ellipsometry, and Hall effect measurements on the electron-doped La{sub x}Ba{sub 1–x}SnO{sub 3} (x = 0.04) transparent thin films. From the infrared Drude response and plasma frequency analysis we determine the effective mass of the conducting electron m* = 0.35m{sub 0}. In the visible-UV region the optical band gap shifts to high energy in (La,Ba)SnO{sub 3} by 0.18 eV compared with undoped BaSnO{sub 3} which, in the context of the Burstein-Moss analysis, is consistent with the infrared-m*. m* of BaSnO{sub 3} is compared with other existing transparent conducting oxides (TCO), and implication on search for high-mobility TCO compounds is discussed.

  9. Deep dry-etch of silica in a helicon plasma etcher for optical waveguide fabrication

    Science.gov (United States)

    Li, W. T.; Bulla, D. A. P.; Love, J.; Luther-Davies, B.; Charles, C.; Boswell, R.

    2005-01-01

    Dry-etch of SiO2 layers using a CF4 plasma in a helicon plasma etcher for optical waveguide fabrication has been studied. Al2O3 thin films, instead of the conventional materials, such as Cr or photoresist, were employed as the masking materials. The Al2O3 mask layer was obtained by periodically oxidizing the surface of an Al mask in an oxygen plasma during the breaks of the SiO2 etching process. A relatively high SiO2/Al2O3 etching selectivity of ~100:1, compared with a SiO2/Al selectivity of ~15:1, was achieved under certain plasma condition. Such a high etching selectivity greatly reduced the required Al mask thickness from over 500 nm down to ~100 nm for etching over 5-μm-thick silica, which make it very easy to obtain the mask patterns with near vertical and very smooth sidewalls. Accordingly, silica wavegudies with vertical sidewalls whose roughness was as low as 10 nm were achieved. In addition, the mechanism of the profile transformation from a mask to the etched waveguide was analyzed numerically; and it was found that the slope angle of the sidewalls of the mask patterns only needed to be larger than 50° for achieving vertical sidewalls of the waveguides, if the etching selectivity was increased to 100.

  10. Isomerization and optical bistability of DR1 doped organic-inorganic sol-gel thin film

    Science.gov (United States)

    Gao, Tianxi; Que, Wenxiu; Shao, Jinyou

    2015-10-01

    To investigate the isomerization process of the disperse red 1 (DR1) doped TiO2/ormosil thin film, both the photo-isomerization and the thermal isomerization of the thin films were observed as a change of the absorption spectrum. Under a real-time heat treatment, the change of the linear refractive index shows a thermal stable working temperature range below Tg. The optical bistability (OB) effect of the DR1 doped thin films based on different matrices was studied and measured at a wavelength of 532 nm. Results indicate that the TiO2/ormosils based thin film presents a better OB-gain than that of the poly (methyl methacrylate) (PMMA) based thin film due to its more rigid network structure. Moreover, it is also noted that higher titanium content is helpful for enhancing the OB-gain of the as-prepared hybrid thin films.

  11. Optical Characterization of Plasma Generated in a Commercial Grade Plasma Etching System

    Science.gov (United States)

    Hardy, Ashley; Drake, Dereth

    2015-11-01

    The use of plasma for etching and cleaning of many types of metal surfaces is becoming more prominent in industry. This is primarily due to the fact that plasma etching can reduce the amount of time necessary to clean/etch the surface and does not require large amounts of environmentally hazardous chemicals. Most plasma etching systems are designed and built in academic institutions. These systems provide reasonable etching rates and easy accessibility for monitoring plasma parameters. The downside is that the cost is typically high. Recently a number of commercial grade plasma etchers have been introduced on the market. These etching systems cost near a fraction of the price, making them a more economical choice for researchers in the field. However, very few academics use these devices because their effectiveness has not yet been adequately verified in the current literature. We will present the results from experiments performed in a commercial grade plasma etching system, including analysis of the pulse characteristics observed by a photo diode and the plasma parameters obtained with optical emission spectroscopy.

  12. Optical Properties of Bi Doped Amorphous Se-Te Thin Films

    Science.gov (United States)

    Kumar, Anup; Heera, Pawan; Barman, P. B.; Sharma, Raman

    2011-12-01

    Effect of Bismuth (Bi) doping on the optical constants of Se-Te thin films, prepared by thermal vacuum evaporation technique, is investigated using Swanepoel method. The optical constants i.e. refractive index (n), film thickness, absorption coefficient and optical energy gap are calculated from the transmission spectra. It has been found that refractive index decreases with wavelength, for all compositions and the absorption coefficient increases with increase in optical energy. On the other hand the optical band gap is found to decreases with increase in Bi content.

  13. Fast figuring of large optics by reactive atom plasma

    Science.gov (United States)

    Castelli, Marco; Jourdain, Renaud; Morantz, Paul; Shore, Paul

    2012-09-01

    The next generation of ground-based astronomical observatories will require fabrication and maintenance of extremely large segmented mirrors tens of meters in diameter. At present, the large production of segments required by projects like E-ELT and TMT poses time frames and costs feasibility questions. This is principally due to a bottleneck stage in the optical fabrication chain: the final figuring step. State-of-the-art figure correction techniques, so far, have failed to meet the needs of the astronomical community for mass production of large, ultra-precise optical surfaces. In this context, Reactive Atom Plasma (RAP) is proposed as a candidate figuring process that combines nanometer level accuracy with high material removal rates. RAP is a form of plasma enhanced chemical etching at atmospheric pressure based on Inductively Coupled Plasma technology. The rapid figuring capability of the RAP process has already been proven on medium sized optical surfaces made of silicon based materials. In this paper, the figure correction of a 3 meters radius of curvature, 400 mm diameter spherical ULE mirror is presented. This work demonstrates the large scale figuring capability of the Reactive Atom Plasma process. The figuring is carried out by applying an in-house developed procedure that promotes rapid convergence. A 2.3 μm p-v initial figure error is removed within three iterations, for a total processing time of 2.5 hours. The same surface is then re-polished and the residual error corrected again down to λ/20 nm rms. These results highlight the possibility of figuring a metre-class mirror in about ten hours.

  14. Collector optic cleaning by in-situ hydrogen plasma

    Science.gov (United States)

    Elg, Daniel T.; Panici, Gianluca A.; Srivastava, Shailendra N.; Ruzic, D. N.

    2015-03-01

    Extreme ultraviolet (EUV) lithography sources produce EUV photons by means of a hot, dense, highly-ionized Sn plasma. This plasma expels high-energy Sn ions and neutrals, which deposit on the collector optic used to focus the EUV light. This Sn deposition lowers the reflectivity of the collector optic, necessitating downtime for collector cleaning and replacement. A method is being developed to clean the collector with an in-situ hydrogen plasma, which provides hydrogen radicals that etch the Sn by forming gaseous SnH4. This method has the potential to significantly reduce collector-related source downtime. EUV reflectivity restoration and Sn cleaning have been demonstrated on multilayer mirror samples attached to a Sn-coated 300mm-diameter steel dummy collector driven at 300W RF power with 500sccm H2 and a pressure of 260mTorr. Use of the in-situ cleaning method is also being studied at industriallyapplicable high pressure (1.3 Torr). Plasma creation across the dummy collector surface has been demonstrated at 1.3 Torr with 1000sccm H2 flow, and etch rates have been measured. Additionally, etching has been demonstrated at higher flow rates up to 3200sccm. A catalytic probe has been used to measure radical density at various pressures and flows. The results lend further credence to the hypothesis that Sn removal is limited not by radical creation but by the removal of SnH4 from the plasma. Additionally, further progress has been made in an attempt to model the physical processes behind Sn removal.

  15. Ellipsometric Characterization of Thin Films from Multicomponent Chalcogenide Glasses for Application in Modern Optical Devices

    Directory of Open Access Journals (Sweden)

    R. Todorov

    2013-01-01

    Full Text Available A review is given on the application of the reflectance ellipsometry for optical characterization of bulk materials and thin films with thickness between λ/20 and 2λ (at λ=632.8 nm. The knowledge of the optical constants (refractive index, n, and extinction coefficient, k of thin films is of a great importance from the point of view of modelling and controlling the manufacture of various optical elements, such as waveguides, diffraction gratings, and microlenses. The presented results concern the optical properties of thin films from multicomponent chalcogenide glasses on the base of As2S3 and GeS2 determined by multiple-angle-of-incidence ellipsometry and regarded as a function of the composition and thickness. The homogeneity of the films is verified by applying single-angle calculations at different angles. Due to decomposition of the bulk glass during thermal evaporation, an optical inhomogeneity of the thin As (Ge-S-Bi(Tl films is observed. The profile of n in depth of thin As-S-Tl (Bi films was investigated by evaporation of discrete layers. It is demonstrated that homogenous layers from the previous compounds with controlled composition can be deposited by coevaporation of As2S3 and metals or their compounds (Bi, Tl, In2S3.

  16. Thermal behavior, structure formation and optical characteristics of nanostructured basic fuchsine thin films

    Energy Technology Data Exchange (ETDEWEB)

    Zeyada, H.M. [Department of Physics, Faculty of Science at New Damietta, Damietta University, 34517, New Damietta (Egypt); Makhlouf, M.M., E-mail: m_makhlof@hotmail.com [Department of Physics, Faculty of Science at New Damietta, Damietta University, 34517, New Damietta (Egypt); Department of Physics, Faculty of Applied Medical Sciences at Turabah Branch, Taif University, 21995 (Saudi Arabia); Department of Physics, Damietta Cancer Institute, Damietta (Egypt); Ismail, M.I.M.; Salama, A.A. [Department of Physics, Faculty of Science, Port Said University, Port Said (Egypt)

    2015-08-01

    Thin films of basic fuchsine, BF, are prepared by thermal evaporation technique. The data of thermal gravimetric analysis, TGA, showed that BF has a thermal stability up to the temperature of 265 °C. The structural characteristics of BF thin films are investigated by using X-ray diffraction, and atomic force microscope techniques. BF is polycrystalline in powder form; it becomes nanocrystallites in thin film condition. Annealing temperatures decreased crystallites size and influenced optical constants of BF films. Optical constants of BF films were estimated by using spectrophotometer measurements of transmittance and reflectance in the spectral range from 190 to 2500 nm. The dependence of absorption coefficient on the photon energy and annealing temperatures was determined and the analysis of the results showed that the optical transition in BF films is indirect allowed one. The onset and fundamental energy gap of BF thin films are 1.91 and 3.72 eV, respectively and they decrease by annealing temperatures. The optical dielectric constants and dispersion parameters of BF thin film are calculated and showed remarkable dependence on photon energy and annealing temperatures. - Graphical abstract: Display Omitted - Highlights: • Polycrystalline BF powder becomes nanocrystallites film upon thermal deposition. • BF has thermal stability up to 265 °C. • BF can be applied as optical filter material. • The type of electron transition is indirect allowed with E{sub g} of 1.91 eV. • Annealing temperatures influenced absorption and dispersion parameters of BF films.

  17. Microscopic thin film optical anisotropy imaging at the solid-liquid interface

    Science.gov (United States)

    Miranda, Adelaide; De Beule, Pieter A. A.

    2016-04-01

    Optical anisotropy of thin films has been widely investigated through ellipsometry, whereby typically an optical signal is averaged over a ˜1 cm2 elliptical area that extends with increasing angle-of-incidence (AOI). Here, we report on spectroscopic imaging ellipsometry at the solid-liquid interface applied to a supported lipid bilayer (SLB). We detail how a differential spectrally resolved ellipsometry measurement, between samples with and without optically anisotropic thin film on an absorbing substrate, can be applied to recover in and out of plane refractive indices of the thin film with known film thickness, hence determining the thin film optical anisotropy. We also present how optimal wavelength and AOI settings can be determined ensuring low parameter cross correlation between the refractive indices to be determined from a differential measurement in Δ ellipsometry angle. Furthermore, we detail a Monte Carlo type analysis that allows one to determine the minimal required optical ellipsometry resolution to recover a given thin film anisotropy. We conclude by presenting a new setup for a spectroscopic imaging ellipsometry based on fiber supercontinuum laser technology, multi-wavelength diode system, and an improved liquid cell design, delivering a 5 ×-10 × ellipsometric noise reduction over state-of-the-art. We attribute this improvement to increased ellipsometer illumination power and a reduced light path in liquid through the use of a water dipping objective.

  18. Thickness and microstructure effects in the optical and electrical properties of silver thin films

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Guowen, E-mail: gding@intermolecular.com; Clavero, César; Schweigert, Daniel; Le, Minh [Intermolecular, Inc., 3011 North First Street, San Jose, CA 95134 (United States)

    2015-11-15

    The optical and electrical response of metal thin films approaching thicknesses in the range of the electron mean free path is highly affected by electronic scattering with the interfaces and defects. Here, we present a theoretical and experimental study on how thickness and microstructure affect the properties of Ag thin films. We are able to successfully model the electrical resistivity and IR optical response using a thickness dependent electronic scattering time. Remarkably, the product of electronic scattering time and resistivity remains constant regardless of the thickness (τx ρ = C), with a value of 59 ± 2 μΩ cm ⋅ fs for Ag films in the investigated range from 3 to 74 nm. Our findings enable us to develop a theoretically framework that allows calculating the optical response of metal thin films in the IR by using their measured thickness and resistivity. An excellent agreement is found between experimental measurements and predicted values. This study also shows the theoretical lower limit for emissivity in Ag thin films according to their microstructure and thickness. Application of the model presented here will allow rapid characterization of the IR optical response of metal thin films, with important application in a broad spectrum of fundamental and industrial applications, including optical coatings, low-emissivity windows and semiconductor industry.

  19. Thickness and microstructure effects in the optical and electrical properties of silver thin films

    Directory of Open Access Journals (Sweden)

    Guowen Ding

    2015-11-01

    Full Text Available The optical and electrical response of metal thin films approaching thicknesses in the range of the electron mean free path is highly affected by electronic scattering with the interfaces and defects. Here, we present a theoretical and experimental study on how thickness and microstructure affect the properties of Ag thin films. We are able to successfully model the electrical resistivity and IR optical response using a thickness dependent electronic scattering time. Remarkably, the product of electronic scattering time and resistivity remains constant regardless of the thickness (τx ρ = C, with a value of 59 ± 2 μΩ cm ⋅ fs for Ag films in the investigated range from 3 to 74 nm. Our findings enable us to develop a theoretically framework that allows calculating the optical response of metal thin films in the IR by using their measured thickness and resistivity. An excellent agreement is found between experimental measurements and predicted values. This study also shows the theoretical lower limit for emissivity in Ag thin films according to their microstructure and thickness. Application of the model presented here will allow rapid characterization of the IR optical response of metal thin films, with important application in a broad spectrum of fundamental and industrial applications, including optical coatings, low-emissivity windows and semiconductor industry.

  20. Temporal structure of double plasma frequency emission of thin beam-heated plasma

    Energy Technology Data Exchange (ETDEWEB)

    Postupaev, V. V.; Ivanov, I. A.; Arzhannikov, A. V.; Vyacheslavov, L. N. [Budker Institute of Nuclear Physics, 11 Lavrentjev Avenue, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, 2 Pirogova st., 630090 Novosibirsk (Russian Federation); Burdakov, A. V.; Polosatkin, S. V. [Budker Institute of Nuclear Physics, 11 Lavrentjev Avenue, 630090 Novosibirsk (Russian Federation); Novosibirsk State Technical University, 20 Karl Marks Avenue, 630092 Novosibirsk (Russian Federation); Sklyarov, V. F.; Gavrilenko, D. Ye.; Kandaurov, I. V.; Kurkuchekov, V. V.; Mekler, K. I.; Popov, S. S.; Rovenskikh, A. F.; Sudnikov, A. V.; Sulyaev, Yu. S.; Trunev, Yu. A. [Budker Institute of Nuclear Physics, 11 Lavrentjev Avenue, 630090 Novosibirsk (Russian Federation); Kasatov, A. A. [Novosibirsk State University, 2 Pirogova st., 630090 Novosibirsk (Russian Federation)

    2013-09-15

    In the work presented here dynamics of spiky microwave emission of a beam-heated plasma near the double plasma frequency in ∼100 GHz band was studied. The plasma is heated by 80 keV, ∼2 MW, sub-ms electron beam that is injected into the multiple-mirror trap GOL-3. The beam-heated plasma diameter is of the order of the emitted wavelength. Modulation of individual emission spikes in the microwave radiation is found. The radiation dynamics observed can be attributed to a small number of compact emitting zones that are periodically distorted.

  1. The effect of FeCl{sub 3} on the optical constants and optical band gap of MBZMA-co-MMA polymer thin films

    Energy Technology Data Exchange (ETDEWEB)

    Yakuphanoglu, F. [Department of Physics, Faculty of Arts and Sciences, Firat University, 23169 Elazig (Turkey)]. E-mail: fyhan@hotmail.com; Barim, G. [Department of Chemistry, Faculty of Arts and Sciences, Firat University, 23169 Elazig (Turkey); Erol, I. [Department of Chemistry, Faculty of Arts and Sciences, Afyon Kocatepe University, Afyon (Turkey)

    2007-03-15

    The effects of the FeCl{sub 3} dopant on the optical constants and optical band gap of the methylbenzyl methacrylate (MBZMA)-co-methyl-methacrylate (MMA) polymer thin films have been investigated by the optical characterization. The optical constants of the thin films are changed with FeCl{sub 3} dopant. The refractive index dispersion curves of the thin films are fitted by Cauchy-Sellmeier model and dispersion parameters (a {sub 1} and n {sub 0}) change with FeCl{sub 3} dopant. The magnitude of the refractive index increases with increasing FeCl{sub 3} dopant. The electric susceptibility of the thin film materials was calculated and the electric susceptibility increases with FeCl{sub 3} content. The optical band gap values of the thin films were determined. The obtained band gap values are decreased with FeCl{sub 3} dopant. The FeCl{sub 3} dopant changes the width of localized states in the optical band gaps of the thin films. The optical band E {sub g} of the thin films changes from 3.52 to 3.05 eV with increasing FeCl{sub 3} dopant, while the width of localized states in optical band gap changes from 1101.47 to 596.3 meV. It is concluded that the optical constants and optical band gap of the MBZMA-co-MMA polymer thin films change by the FeCl{sub 3} dopant.

  2. Amine Enrichment of Thin-Film Composite Membranes via Low Pressure Plasma Polymerization for Antimicrobial Adhesion.

    Science.gov (United States)

    Reis, Rackel; Dumée, Ludovic F; He, Li; She, Fenghua; Orbell, John D; Winther-Jensen, Bjorn; Duke, Mikel C

    2015-07-15

    Thin-film composite membranes, primarily based on poly(amide) (PA) semipermeable materials, are nowadays the dominant technology used in pressure driven water desalination systems. Despite offering superior water permeation and salt selectivity, their surface properties, such as their charge and roughness, cannot be extensively tuned due to the intrinsic fabrication process of the membranes by interfacial polymerization. The alteration of these properties would lead to a better control of the materials surface zeta potential, which is critical to finely tune selectivity and enhance the membrane materials stability when exposed to complex industrial waste streams. Low pressure plasma was employed to introduce amine functionalities onto the PA surface of commercially available thin-film composite (TFC) membranes. Morphological changes after plasma polymerization were analyzed by SEM and AFM, and average surface roughness decreased by 29%. Amine enrichment provided isoelectric point changes from pH 3.7 to 5.2 for 5 to 15 min of plasma polymerization time. Synchrotron FTIR mappings of the amine-modified surface indicated the addition of a discrete 60 nm film to the PA layer. Furthermore, metal affinity was confirmed by the enhanced binding of silver to the modified surface, supported by an increased antimicrobial functionality with demonstrable elimination of E. coli growth. Essential salt rejection was shown minimally compromised for faster polymerization processes. Plasma polymerization is therefore a viable route to producing functional amine enriched thin-film composite PA membrane surfaces.

  3. a-C:H/a-C:H(N) thin film deposition using 2.45 GHz expanding surface wave sustained plasmas

    Science.gov (United States)

    Hong, Suk-Ho; Douai, David; Berndt, Johannes; Winter, Jörg

    2005-08-01

    Thin film properties such as homogeneity (radial profiles), optical constants, carbon density in the film, and the surface structures are strongly dependent on deposition conditions. We have investigated a-C:H/a-C:H(N) thin film deposition by expanding Ar-CH4 and Ar/N2-CH4 surface wave sustained plasmas at a frequency of 2.45 GHz. The influence of the plasma parameters such as pressure, input power, gas mixture rate, and an external bias voltage on the change of the film properties is systematically studied. An external bias applied to the substrate leads to more dense and harder a-C:H films, i.e. change from soft polymer-like to hard diamond-like. Rutherford backscattering and atomic force microscope surface topology confirm the densification of the films.

  4. Optical properties of epitaxial Casub>xsub>Basub>1-xsub>Nbsub>2sub>Osub>6sub> thin film based rib-waveguide structure on (001) MgO for electro-optic applications.

    Science.gov (United States)

    Vigne, Sébastien; Hossain, Nadir; Fesharaki, Faezeh; Kabir, S M Humayun; Margot, Joëlle; Wu, Ke; Chaker, Mohamed

    2016-12-12

    In this work, optical properties of epitaxial Casub>xsub>Basub>1-xsub>Nbsub>2sub>Osub>6sub>, CBN (x = 0.28) thin film based waveguides are studied at 1550 nm optical communications wavelength. CBN thin films are deposited epitaxially on MgO substrates using Pulsed Laser Deposition and characterized by prism coupling to extract the refractive index and propagation loss. It is shown that the 2 µm-thick epitaxial CBN thin films have a refractive index close to the bulk form and the CBN planar waveguides have a propagation loss of 4.3 ± 0.5 dB/cm. 1 cm-long rib waveguide structures were fabricated using a high density plasma etching. Their propagation losses were measured by the cutback method at 8.4 ± 0.6 dB/cm.

  5. Optical characterization of antimony-based bismuth-doped thin films with different annealing temperatures

    Institute of Scientific and Technical Information of China (English)

    Xinmiao Lu; Yiqun Wu; Yang Wang; Jinsong Wei

    2011-01-01

    Antimony-b ased bismuth-doped thin film,a new kind of super-resolution mask layer,is prepared by magnetron sputtering.The structures and optical constants of the thin films before and after annealing are examined in detail.The as-deposited film is mainly in an amorphous state.After annealing at 170-370℃,it is converted to the rhombohedral-type of structure.The extent of crystallization increased with the annealing temperature.When the thin film is annealed,its refractive index decreased in the most visible region,whereas the extinction coefficient and reflectivity are markedly increased.The results indicate that the optical parameters of the film strongly depend on its microstructure and the bonding of the atoms.As demand for ultrahigh-density information storage continues to grow the recording mark size in optical memory is reduced to the nanometer scale [1- 4].Exceeding the optical diffraction limit with traditional optical storage technology has become a challenge[5-6].%Antimony-based bismuth-doped thin film, a new kind of super-resolution mask layer, is prepared by magnetron sputtering. The structures and optical constants of the thin films before and after annealing are examined in detail. The as-deposited film is mainly in an amorphous state. After annealing at 170-370℃, it is converted to the rhombohedral-type of structure. The extent of crystallization increased with the annealing temperature. When the thin film is annealed, its refractive index decreased in the most visible region, whereas the extinction coefficient and reflectivity are markedly increased. The results indicate that the optical parameters of the film strongly depend on its microstructure and the bonding of the atoms.

  6. Impact of Argon gas on optical and electrical properties of Carbon thin films

    Energy Technology Data Exchange (ETDEWEB)

    Usman, Arslan, E-mail: arslan.usman@gmail.com [Department of Physics, COMSATS Institute of Information Technology, Lahore (Pakistan); Rafique, M.S. [Department of Physics, University of Engineering & Technology, Lahore 54890 (Pakistan); Shaukat, S.F. [Department of Physics, COMSATS Institute of Information Technology, Lahore (Pakistan); Siraj, Khurram [Department of Physics, University of Engineering & Technology, Lahore 54890 (Pakistan); Ashfaq, Afshan [Institute of Nuclear Medicine and Oncology Lahore (INMOL), 54000 Pakistan (Pakistan); Anjum, Safia [Department of Physics, Lahore College for Women University (Pakistan); Imran, Muhammad; Sattar, Abdul [Department of Physics, COMSATS Institute of Information Technology, Lahore (Pakistan)

    2016-12-15

    Nanostructured thin films of carbon were synthesized and investigated for their electrical, optical, structural and surface properties. Pulsed Laser Deposition (PLD) technique was used for the preparation of these films under Argon gas environment. A KrF Laser (λ=248 nm) was used as source of ablation and plasma formation. It was observed that the carbon ions and the background gas environment has deep impact on the morphology as well as on the microstructure of the films. Time of Flight (TOF) method was used to determine the energies of the ablated carbon ions. The morphology of film surfaces deposited at various argon pressure was analysed using an atomic force microscope. The Raman spectroscopic measurement reveal that there is shift in phase from sp{sup 3} to sp{sup 2} and a decrease in FWHM of G band, which is a clear indication of enhanced graphitic clusters. The electrical resistivity was also reduced from 85.3×10{sup −1} to 2.57×10{sup −1} Ω-cm. There is an exponential decrease in band gap E{sub g} of the deposited films from 1.99 to 1.37 eV as a function of argon gas pressure.

  7. Impact of Argon gas on optical and electrical properties of Carbon thin films

    Science.gov (United States)

    Usman, Arslan; Rafique, M. S.; Shaukat, S. F.; Siraj, Khurram; Ashfaq, Afshan; Anjum, Safia; Imran, Muhammad; Sattar, Abdul

    2016-12-01

    Nanostructured thin films of carbon were synthesized and investigated for their electrical, optical, structural and surface properties. Pulsed Laser Deposition (PLD) technique was used for the preparation of these films under Argon gas environment. A KrF Laser (λ=248 nm) was used as source of ablation and plasma formation. It was observed that the carbon ions and the background gas environment has deep impact on the morphology as well as on the microstructure of the films. Time of Flight (TOF) method was used to determine the energies of the ablated carbon ions. The morphology of film surfaces deposited at various argon pressure was analysed using an atomic force microscope. The Raman spectroscopic measurement reveal that there is shift in phase from sp3 to sp2 and a decrease in FWHM of G band, which is a clear indication of enhanced graphitic clusters. The electrical resistivity was also reduced from 85.3×10-1 to 2.57×10-1 Ω-cm. There is an exponential decrease in band gap Eg of the deposited films from 1.99 to 1.37 eV as a function of argon gas pressure.

  8. Participation of the Third Order Optical Nonlinearities in Nanostructured Silver Doped Zinc Oxide Thin Solid Films

    Directory of Open Access Journals (Sweden)

    C. Torres-Torres

    2012-01-01

    Full Text Available We report the transmittance modulation of optical signals in a nanocomposite integrated by two different silver doped zinc oxide thin solid films. An ultrasonic spray pyrolysis approach was employed for the preparation of the samples. Measurements of the third-order nonlinear optical response at a nonresonant 532 nm wavelength of excitation were performed using a vectorial two-wave mixing. It seems that the separated contribution of the optical nonlinearity associated with each film noticeable differs in the resulting nonlinear effects with respect to the additive response exhibited by the bilayer system. An enhancement of the optical Kerr nonlinearity is predicted for prime number arrays of the studied nanoclusters in a two-wave interaction. We consider that the nanostructured morphology of the thin solid films originates a strong modification of the third-order optical phenomena exhibited by multilayer films based on zinc oxide.

  9. Optical properties of hexagonal boron nitride thin films deposited by radio frequency bias magnetron sputtering

    Institute of Scientific and Technical Information of China (English)

    Deng Jin-Xiang; Zhang Xiao-Kang; Yao Qian; Wang Xu-Yang; Chen Guang-Hua; He De-Yan

    2009-01-01

    The optical properties of hexagonal boron nitride (h-BN) thin films were studied in this paper. The films were characterized by Fourier transform infrared spectroscopy,UV-visible transmittance and reflection spectra,h-BN thin films with a wide optical band gap Eg (5.86 eV for the as-deposited film and 5.97 eV for the annealed film) approaching h-BN single crystal were successfully prepared by radio frequency (RF) bias magnetron sputtering and post-deposition annealing at 970 K. The optical absorption behaviour of h-BN films accords with the typical optical absorption characteristics of amorphous materials when fitting is made by the Urbach tail model. The annealed film shows satisfactory structure stability. However,high temperature still has a significant effect on the optical absorption properties,refractive index n,and optical conductivity σ of h-BN thin films. The blue-shift of the optical absorption edge and the increase of Eg probably result from stress relaxation in the film under high temperatures. In addition,it is found that the refractive index clearly exhibits different trends in the visible and ultraviolet regions. Previous calculational results of optical conductivity of h-BN films are confirmed in our experimental results.

  10. Ion acceleration and plasma jet formation in ultra-thin foils undergoing expansion and relativistic transparency

    Energy Technology Data Exchange (ETDEWEB)

    King, M.; Gray, R.J.; Powell, H.W.; MacLellan, D.A.; Gonzalez-Izquierdo, B. [SUPA Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Stockhausen, L.C. [Centro de Laseres Pulsados (CLPU), Parque Cientifico, Calle del Adaja, s/n. 37185 Villamayor, Salamanca (Spain); Hicks, G.S.; Dover, N.P. [The John Adams Institute for Accelerator Science, Blackett Laboratory, Imperial College London, London SW7 2BZ (United Kingdom); Rusby, D.R. [SUPA Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire OX11 0QX (United Kingdom); Carroll, D.C. [Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire OX11 0QX (United Kingdom); Padda, H. [SUPA Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Torres, R. [Centro de Laseres Pulsados (CLPU), Parque Cientifico, Calle del Adaja, s/n. 37185 Villamayor, Salamanca (Spain); Kar, S. [Centre for Plasma Physics, Queens University Belfast, Belfast BT7 1NN (United Kingdom); Clarke, R.J.; Musgrave, I.O. [Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire OX11 0QX (United Kingdom); Najmudin, Z. [The John Adams Institute for Accelerator Science, Blackett Laboratory, Imperial College London, London SW7 2BZ (United Kingdom); Borghesi, M. [Centre for Plasma Physics, Queens University Belfast, Belfast BT7 1NN (United Kingdom); Neely, D. [Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire OX11 0QX (United Kingdom); McKenna, P., E-mail: paul.mckenna@strath.ac.uk [SUPA Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom)

    2016-09-01

    At sufficiently high laser intensities, the rapid heating to relativistic velocities and resulting decompression of plasma electrons in an ultra-thin target foil can result in the target becoming relativistically transparent to the laser light during the interaction. Ion acceleration in this regime is strongly affected by the transition from an opaque to a relativistically transparent plasma. By spatially resolving the laser-accelerated proton beam at near-normal laser incidence and at an incidence angle of 30°, we identify characteristic features both experimentally and in particle-in-cell simulations which are consistent with the onset of three distinct ion acceleration mechanisms: sheath acceleration; radiation pressure acceleration; and transparency-enhanced acceleration. The latter mechanism occurs late in the interaction and is mediated by the formation of a plasma jet extending into the expanding ion population. The effect of laser incident angle on the plasma jet is explored.

  11. Optical characterization of ZnO thin films deposited by RF magnetron sputtering method

    Institute of Scientific and Technical Information of China (English)

    TANG Ning; WANG JinLiang; XU HengXing; PENG HongYong; FAN Chao

    2009-01-01

    This study investigated the process parameter effects on the structural and optical properties of ZnO thin film using radio frequency(RF)magnetron sputtering on amorphous glass substrates.The process parameters included RF power and working pressure.Results show that RF power was increased to promote the crystalline quality and decrease ZnO thin film defects.However,when the working pressure was increased to 3 Pa the ZnO thin film crystalline quality became worse.At a 200 W RF power and 1 Pa working pressure,the ZnO thin film with an optical band gap energy of 3.225 eV was obtained.

  12. Structural and optical study of nanostructure of 4-cyanopyranoquinolinedione (CPQ) thin films

    Science.gov (United States)

    Soliman, H. S.; Ibrahim, M.; El-Mansy, M. A. M.; Atef, S. M.

    2017-10-01

    Thin films of 4-cyanopyranoquinolinedione, CPQ, with different thicknesses were deposited by thermal evaporation method. The structural properties of powder and thin films were investigated using X-ray diffraction technique. The crystal structure, lattice parameters and Miller indices of the powder were indexed. The crystalline size, strain and dislocation density were determined for powder and thin films. The optical properties of CPQ thin films were studied using spectrophotometric measurements of both transmittance and reflectance in the wavelength range 200-2500 nm. HOMO-LUMO band gap was determined by cyclic voltammetry. The calculation of optical band gap using absorption coefficient showed that the film has direct allowed transition with 3.02 eV energy gap. The normal dispersion of the refractive index of the films was described by Wemple-DiDomenico single oscillator model. Some dispersion parameters were calculated. Also, the real and imaginary parts of dielectric constant, volume and surface energy loss functions were estimated.

  13. The Gridless Plasma Ion Source(GIS)for Plasma Ion Assisted Optical Coating

    Institute of Scientific and Technical Information of China (English)

    尤大伟; 李晓谦; 王宇; 林永昌

    2004-01-01

    High-quality optical coating is a key technology for modern optics. Ion-assisted deposition technology was used to improve the vaporized coating in 1980's. The GIS (gridless ion source), which is an advanced plasma source for producing a high-quality optical coating in large area, can produce a large area uniformity>1000 mm(diameter), a high ion current density ~ 0.5mA/cm2, 20 eV ~ 200 eV energetic plasma ions and can activate reactive gas and film atoms. Now we have developed a GIS system. The GIS and the plasma ion-assisted deposition technology are investigated to achieve a high-quality optical coating. The GIS is a high power and high current source with a power of I kW ~ 7.5 kW, a current of 10 A ~ 70 A and an ion density of 200μA/cm2 ~ 500μA/cm2. Because of the special magnetic structure, the plasma-ion extraction efficiency has been improved to obtain a maximum ion density of 500μA/cm2 in the medium power (~ 4 kW) level. The GIS applied is of a special cathode structure, so that the GIS operation can be maintained under a rather low power and the lifetime of cathode will be extended. The GIS has been installed in the LPSX-1200 type box coating system. The coated TiO2, SiO2 films such as antireflective films with the system have the same performance reported by Leybold Co, 1992, along with a controllable refractive index and film structure.

  14. Optical endpoint detection for plasma reduction of graphene oxide

    Directory of Open Access Journals (Sweden)

    MaengJun Kim

    2013-03-01

    Full Text Available The plasma reduction process for the production of reduced graphene oxide (rGO requires precise process control in order to avoid the degradation of electrical characteristics. We report that the reduction status of the graphene oxides could be determined by monitoring the optical emission intensity at 844.6 nm. Properties of the rGO samples processed with various plasma exposure times were characterized by X-ray photoelectron spectroscopy, Raman spectroscopy, atomic force microscopy, and 4-point probe measurements. Optimum electrical performance and surface morphology were obtained from the sample for which the reduction process was stopped when the emission intensity at 844.6 nm began to decrease.

  15. Optical Rectification in Isotropic Thin Film Composed of Chiral Molecules with a Tripod-Like Structure

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-Ou; GONG Li-Jing; LI Chun-Fei

    2008-01-01

    @@ Optical rectification (OR) effect in the isotropic thin film consisting of chiral molecules with a tripod-like structure is investigated.The expressions of static-electric polarization in the isotropic chiral thin films and the relations between the OR and microscopic parameters of chiral medium are obtaineel by theoretical derivation,Furthermore,the relations of static electric polarization with the wavelength of incident light and parameters of chiral molecules are simulated numerically.

  16. Thin As-Se-Sb Films as Potential Medium for Optics and Sensor Application

    Science.gov (United States)

    Ilcheva, Vania; Boev, V.; Petkova, T.; Petkov, Plamen; Petkov, Emil; Socol, G.; Mihailescu, I. N.

    Thin films have been deposited onto quartz substrates by the pulsed laser deposition (PLD) method from the corresponding glassy bulk As-Se-Sb chalcogenide materials. Photoinduced changes have been observed after illumination of the films with a Xe lamp. The transmission spectra of the thin films have been measured before and after irradiation and the optical constants have been derived by the Swanepoel method. The results suggest feasible applications of these materials for waveguide-sensors.

  17. Optical modulator based on propagating surface plasmon coupled fluorescent thin film: proof-of-concept studies

    Science.gov (United States)

    Cao, Shuo-Hui; Wang, Zheng-Chuang; Weng, Yu-Hua; Xie, Kai-Xin; Chen, Min; Zhai, Yan-Yun; Li, Yao-Qun

    2017-06-01

    We demonstrate that the propagating surface plasmon coupled fluorescent thin film can be utilized as a fluorescence modulator to mimic multiple representative Boolean logic operations. Surface plasmon mediated fluorescence presents characteristic properties including directional and polarized emission, which hold the feasibility in creating a universal optical modulator. In this work, through constructing the thin layer with the specific thickness, surface plasmon mediated fluorescence can be modulated with an ON-OFF ratio by more than 5-fold, under a series of coupling configurations.

  18. Correlation between composition, morphology and optical properties of PVK: n-ZnO:CTAB thin films

    Science.gov (United States)

    Azizi, Samir; Belhaj, Marwa; Zargouni, Sarra; Dridi, Cherif

    2017-07-01

    In this study, we report on the effect of zinc oxide nanoparticles ( n-ZnO) content and surfactant addition on the performance of poly ( N-vinylcarbazole) (PVK): n-ZnO nanocomposite thin films. Morphological and optical properties of ZnO, PVK and PVK: n-ZnO:cetyltrimethyl ammonium bromide (CTAB) hybrid films were investigated by atomic force microscopy (AFM), UV-Visible spectrophotometry and photoluminescence (PL) spectroscopy. We noticed that surface morphology was very dependent on surfactant addition into inorganic and organic components and on the ZnO content in the mixture. The optical absorption spectra of PVK: n-ZnO thin films showed a red shift of the optical band gap energy. Besides, PL measurements demonstrated an interfacial charge transfer between PVK matrix and ZnO nanoparticles through the reduced PL intensity of nanocomposites compared to PVK thin films.

  19. Simulation of reflectivity spectrum for non-absorbing multilayer optical thin films

    Indian Academy of Sciences (India)

    V A Kheraj; C J Panchal; M S Desai; V Potbhare

    2009-06-01

    Reflectivity simulation is an essential tool for the design and optimization of optical thin films. We have developed a reflectivity simulator for non-absorbing dielectric multilayer optical thin films using LabVIEW. The name of the substrate material as well as the material and thickness of each layer of the multilayer stack are fed into the program as input parameters in a pop-up window. The program calculates reflectivity spectrum for the given range of wavelengths using layer thicknesses and dispersion data of refractive indices for the defined stack of dielectric materials. The simulated reflectivity spectra for various combinations of materials in multilayer stacks are presented and compared with the experimental results of the multilayer optical thin films grown by electron-beam evaporation technique.

  20. A quantum size effect in infrared optical response of aliminum thin films

    Science.gov (United States)

    Xiao, Mufei; Villagómez, Ricardo

    1998-03-01

    We present a quantum mechanical calculation for diamagnetic optical response of metallic thin films. The study shows that in the optical response of the thin films, such as the reflectance, there exists an oscillatory dependence on the film thickness when the film contents less than about 100 monolayers, and the period of the oscillation corresponds to one or few monolayers. We show that the oscillation can be attributed to the intraband fluctuations of the valence electrons at discrete energy states as well as at continuum energy states. For comparison, we present some experimental results for Aluminum thin films of thickness 5 ~112ÅInfrared (λ=9.2μ m) optical reflectance of the films was measured, which demonstrates experimentally the predicted oscillating fine structures.

  1. Atomic Layer Deposition Al2O3 Thin Films in Magnetized Radio Frequency Plasma Source

    Science.gov (United States)

    Li, Xingcun; Chen, Qiang; Sang, Lijun; Yang, Lizhen; Liu, Zhongwei; Wang, Zhenduo

    Self-limiting deposition of aluminum oxide (Al2O3) thin films were accomplished by the plasma-enhanced chemical vapor deposition using trimethyl aluminum (TMA) and O2 as precursor and oxidant, respectively, where argon was kept flowing in whole deposition process as discharge and purge gas. In here we present a novel plasma source for the atomic layer deposition technology, magnetized radio frequency (RF) plasma. Difference from the commercial RF source, magnetic coils were amounted above the RF electrode, and the influence of the magnetic field strength on the deposition rate and morphology are investigated in detail. It concludes that a more than 3 Å/ purging cycle deposition rate and the good quality of ALD Al2O3 were achieved in this plasma source even without extra heating. The ultra-thin films were characterized by including Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectric spectroscopy (XPS), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The high deposition rates obtained at ambient temperatures were analyzed after in-situ the diagnostic of plasmas by Langmuir probe.

  2. Structure and composition effects on electrical and optical properties of sputtered PbSe thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xigui; Gao, Kewei [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); Pang, Xiaolu, E-mail: pangxl@mater.ustb.edu.cn [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); Yang, Huisheng [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); Volinsky, Alex A. [Department of Mechanical Engineering, University of South Florida, Tampa, FL 33620 (United States)

    2015-10-01

    Lead selenide (PbSe) thin films were grown on Si (111) substrates using magnetron sputtering, and the structure and composition effects on the photoelectric and optical properties of the sputtered PbSe thin films were studied using field emission scanning electron microscope, energy dispersive X-ray detector, X-ray diffraction, X-ray photoelectron spectroscopy, physical property measurement system and Fourier transform infrared spectroscopy. The optical band gaps of all the sputtered PbSe thin films ranged from 0.264 eV to 0.278 eV. The PbSe thin film prepared with oxygen flux 1.0 sccm, deposition time 240 min, sputtering power 150 W and substrate temperature 150 °C showed the highest resistance change rate under illumination, about 84.47%. The variation trends of the photoelectric and optical properties with the average crystal size, lattice constant, oxygen content and lattice oxygen percentage were similar, respectively. The sputtered PbSe thin films showed poor photoelectric sensitivity, when the average crystal size was similar to the Bohr radius (46 nm), while the photoelectric sensitivity increased almost linearly with the oxygen content in the thin films, indicating that both deviating the average crystal size from the Bohr radius and increasing the oxygen content are two direct and effective ways to obtain high photoelectric sensitivity in PbSe thin films. - Highlights: • Lead selenide thin films were grown on Si (111) using magnetron sputtering. • Lead selenide thin films show superior photoelectric sensitivity. • The effects of structure and composition to the film properties were studied. • The photoelectric property was mainly affected by grain size and oxygen content.

  3. Pulsed laser deposited Al-doped ZnO thin films for optical applications

    Directory of Open Access Journals (Sweden)

    Gurpreet Kaur

    2015-02-01

    Full Text Available Highly transparent and conducting Al-doped ZnO (Al:ZnO thin films were grown on glass substrates using pulsed laser deposition technique. The profound effect of film thickness on the structural, optical and electrical properties of Al:ZnO thin films was observed. The X-ray diffraction depicts c-axis, plane (002 oriented thin films with hexagonal wurtzite crystal structure. Al-doping in ZnO introduces a compressive stress in the films which increase with the film thickness. AFM images reveal the columnar grain formation with low surface roughness. The versatile optical properties of Al:ZnO thin films are important for applications such as transparent electromagnetic interference (EMI shielding materials and solar cells. The obtained optical band gap (3.2–3.08 eV was found to be less than pure ZnO (3.37 eV films. The lowering in the band gap in Al:ZnO thin films could be attributed to band edge bending phenomena. The photoluminescence spectra gives sharp visible emission peaks, enables Al:ZnO thin films for light emitting devices (LEDs applications. The current–voltage (I–V measurements show the ohmic behavior of the films with resistivity (ρ~10−3 Ω cm.

  4. Adaptive optical design in surface plasma resonance sensor

    Institute of Scientific and Technical Information of China (English)

    ZHANG Feng; ZHONG Jin-gang

    2006-01-01

    A double-prism adaptive optical design in surface plasma resonance (SPR) sensor is proposed,which consists of two identical isosceles right-triangular prisms. One prism is used as a component of Kretschmann configuration,and the other is for regulation of the optical path. When double-prism structure is angle-scanned by an immovable incident ray,the output ray will be always parallel with the incident ray and just has a small displacement with the shift of output point.The output ray can be focused on a fixed photodetector by a convex lens.Thus it can be avoided that a prism and a photodetector rotate by θ and 2θ respectively in conventional angular scanning SPR sensor.This new design reduces the number of the movable components,makes the structure simple and compact,and makes the manipulation convenient.

  5. Thinning and functionalization of few-layer graphene sheets by CF4 plasma treatment

    KAUST Repository

    Shen, Chao

    2012-05-24

    Structural changes of few-layer graphene sheets induced by CF4 plasma treatment are studied by optical microscopy and Raman spectroscopy, together with theoretical simulation. Experimental results suggest a thickness reduction of few-layer graphene sheets subjected to prolonged CF4 plasma treatment while plasma treatment with short time only leads to fluorine functionalization on the surface layer by formation of covalent bonds. Raman spectra reveal an increase in disorder by physical disruption of the graphene lattice as well as functionalization during the plasma treatment. The F/CF3 adsorption and the lattice distortion produced are proved by theoretical simulation using density functional theory, which also predicts p-type doping and Dirac cone splitting in CF4 plasma-treated graphene sheets that may have potential in future graphene-based micro/nanodevices.

  6. High-energy ion treatments of amorphous As40Se60 thin films for optical applications

    OpenAIRE

    Rashmi Chauhan; Arvind Tripathi; Krishna Kant Srivastava

    2014-01-01

    The treatment of 100 MeV Ag swift-heavy ion (SHI) irradiation with five different fluences (3×1010, 1×1011, 3×1011, 1×1012, and 3×1012 ions/cm2) was used to design optical and structural properties of amorphous (a-) As40Se60 chalcogenide thin films. Swanepoel method was applied on transmission measurements to determine the changes in optical bandgap, Tauc parameter and linear optical parameters, i.e., linear optical absorption, extinction coefficient and linear refractive index. Dispersion of...

  7. High-energy ion treatments of amorphous As40Se60 thin films for optical applications

    OpenAIRE

    Chauhan, Rashmi; Tripathi, Arvind; Srivastava, Krishna Kant

    2014-01-01

    The treatment of 100 MeV Ag swift-heavy ion (SHI) irradiation with five different fluences (3×1010, 1×1011, 3×1011, 1×1012, and 3×1012 ions/cm2) was used to design optical and structural properties of amorphous (a-) As40Se60 chalcogenide thin films. Swanepoel method was applied on transmission measurements to determine the changes in optical bandgap, Tauc parameter and linear optical parameters, i.e., linear optical absorption, extinction coefficient and linear refractive index. Dispersion of...

  8. Determination of optical properties in nanostructured thin films using the Swanepoel method

    Science.gov (United States)

    Sánchez-González, J.; Díaz-Parralejo, A.; Ortiz, A. L.; Guiberteau, F.

    2006-06-01

    We present the methodological framework of the Swanepoel method for the spectrophotometric determination of optical properties in thin films using transmittance data. As an illustrative case study, we determined the refractive index, thickness, absorption index, and extinction coefficient of a nanostructured 3 mol% Y 2O 3-doped ZrO 2 (yttria stabilized zirconia, 3YSZ) thin film prepared by the sol-gel method and deposited by dipping onto a soda-lime glass substrate. In addition, using the absorption index obtained with the Swanepoel method, we calculated the optical band gap of the film. The refractive index was found to increase, then decrease, and finally stabilize with increasing wavelength of the radiation, while the absorption index and extinction coefficient decreased monotonically to zero. These trends are explained in terms of the location of the absorption bands. We also deduced that this 3YSZ thin film has a direct optical band gap of 4.6 eV. All these results compared well with those given in the literature for similar thin films. This suggests that the Swanepoel method has an important role to play in the optical characterization of ceramic thin films.

  9. Optical and structural properties of PbI2 thin film produced via chemical dipping method

    Science.gov (United States)

    Kariper, İ. A.

    2016-06-01

    PbI2 thin films were deposited on glass substrates via chemical bath deposition. The characteristics of PbI2 thin films were examined through their structural and optical properties. X-ray diffraction spectra showed the presence of rhombohedral structure and atom planes were subject to change with the pH of the bath. Scanning electron microscope indicated uniform distribution of grains. Optical properties were examined via UV-VIS; optical spectrum of the thin films was measured at the range of 200-1100 nm wavelength. Optimum pH levels for producing thin films were found to be pH 4-5. It has been observed that transmission and optical band gap ( E g) increased with the pH of the bath, which varied between 66-95 and 2.24-2.50 %, respectively; on the other hand film thickness of PbI2 thin films was decreased with the pH of the bath. Energy-dispersive X-ray spectroscopy analysis were in accordance with theoretical value of PbI2 at pH = 4 and 5. Refractive index was negatively correlated with pH of the chemical bath; it has been calculated as 1.97, 1.40, 1.29 and 1.24 for the films produced at pH 2, 3, 4 and 5. The results of the study were compared with similar studies in the literature.

  10. Influence of Electron Irradiation on Optical Properties of ZnSe Thin Films

    OpenAIRE

    P. Raghu; C.S. Naveen; K. Mrudula; Sanjeev Ganesh; J. Shailaja; H.M. Mahesh

    2014-01-01

    Zinc Selenide (ZnSe) thin films of 500 nm thickness were deposited by electron beam evaporation technique and irradiated with 8 MeV electron beam for the doses ranging from 0 Gy to 1 kGy. Optical properties were studied for both irradiated and pristine samples using Ultraviolet-Visible spectrophotometer. The increase in electron dose tends to decrease in transmittance and increase in refractive index of thin film. Irradiated thin film exhibits minimum of 67 % transmittance for 800 Gy with ver...

  11. Quantum Electron Plasma, Visible and Ultraviolet P-wave and Thin Metallic Film

    CERN Document Server

    Yushkanov, A A

    2016-01-01

    The interaction of the visible and ultraviolet electromagnetic P-wave with the thin flat metallic film localized between two dielectric media is studied numerically in the framework of the quantum degenerate electron plasma approach. The reflectance, transmittance and absorptance power coefficients are chosen for investigation. It is shown that for the frequencies in the visible and ultraviolet ranges, the quantum power coefficients differ from the ones evaluated in framework of both the classical spatial dispersion and the Drude - Lorentz approaches.

  12. Quantum electron plasma, visible and ultraviolet P-wave and thin metallic film

    Science.gov (United States)

    Yushkanov, A. A.; Zverev, N. V.

    2017-02-01

    The interaction of the visible and ultraviolet electromagnetic P-wave with the thin flat metallic film localized between two dielectric media is studied numerically in the framework of the quantum degenerate electron plasma approach. The reflectance, transmittance and absorptance power coefficients are chosen for investigation. It is shown that for the frequencies in the visible and ultraviolet ranges, the quantum power coefficients differ from the ones evaluated in framework of both the classical spatial dispersion and the Drude-Lorentz approaches.

  13. Quantum electron plasma, visible and ultraviolet P-wave and thin metallic film

    Energy Technology Data Exchange (ETDEWEB)

    Yushkanov, A.A., E-mail: yushkanov@inbox.ru; Zverev, N.V., E-mail: zverev_nv@mail.ru

    2017-02-12

    The interaction of the visible and ultraviolet electromagnetic P-wave with the thin flat metallic film localized between two dielectric media is studied numerically in the framework of the quantum degenerate electron plasma approach. The reflectance, transmittance and absorptance power coefficients are chosen for investigation. It is shown that for the frequencies in the visible and ultraviolet ranges, the quantum power coefficients differ from the ones evaluated in framework of both the classical spatial dispersion and the Drude–Lorentz approaches.

  14. Optical, electrical and thermoelectric power studies of Al–Sb thin film bilayer structure

    Indian Academy of Sciences (India)

    M Singh; J S Arora; Y K Vijay; M Sudharshan

    2006-02-01

    The III–V semiconductors are of great importance due to their applications in various electro-optic devices. The Al–Sb thin film was deposited on glass substrate by thermal evaporation method at a pressure of 10-5 torr. The samples were annealed for 3 h at different constant temperatures in a vacuum chamber at a pressure of 10-5 torr. The electrical resistance vs temperature studies show phase transformation from metallic to semiconducting. The observed positive thermoelectric power indicates that Al–Sb thin films are -type in nature. The Rutherford back scattering analysis and optical band gap measurements also indicate that the interdiffusion concentration varies with temperature.

  15. Effect of substrate temperature on structural, morphological, optical and electrical properties of IGZO thin films

    Science.gov (United States)

    Jayaraman, Vinoth Kumar; Álvarez, Arturo Maldonado; Olvera Amador, María de la luz

    2017-02-01

    Indium and gallium co-doped zinc oxide (IGZO) thin films were deposited on glass substrates by ultrasonic spray pyrolysis. Physical properties such as structural, morphological, optical and electrical properties were examined on IGZO thin films with respect to the changes in the substrate temperature (425, 450 and 475 °C). Structural results showed that IGZO films were crystalline and presented hexagonal wurtzite structure. Morphological studies proved that the substrate temperature changed the sizes of hexagonal nanostructures of IGZO. Optical transmittance in the UV-vis region and electrical measurements confirmed that IGZO films were transparent (>70%) with a minimum electrical resistivity 10.5×10-3 Ω cm.

  16. Structure and Optical Properties of Nanocrystalline Hafnium Oxide Thin Films (PostPrint)

    Science.gov (United States)

    2014-09-01

    AFRL-RX-WP-JA-2014-0214 STRUCTURE AND OPTICAL PROPERTIES OF NANOCRYSTALLINE HAFNIUM OXIDE THIN FILMS (POSTPRINT) Neil R. Murphy AFRL...OPTICAL PROPERTIES OF NANOCRYSTALLINE HAFNIUM OXIDE THIN FILMS (POSTPRINT) 5a. CONTRACT NUMBER In-House 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...publication is available at http://dx.doi.org/10.1016/j.optmat.2014.08.005 14. ABSTRACT Hafnium oxide (HfO2) films were grown by sputter-deposition by

  17. Optical characterization of Cu3N thin film with Swanepoel method

    Science.gov (United States)

    Dorranian, Davoud; Dejam, Laya; Mosayebian, Gelareh

    2012-07-01

    Swanepoel method is employed for spectroscopic determination of optical properties of Cu3N thin film using transmittance data. Investigated films have been deposited using reactive magnetron sputtering system. Deposition time was 9 to 21 min. Refractive index, absorption coefficient, and bandgap energy of the samples are determined. Thickness of the films is calculated by Swanepoel method, and result is compared with the thickness of the films measured by profilmeter. It is shown that Swanepoel method is a reliable way to calculate the optical constants of thin films when the transmittance spectrum of the film is influenced by wavelike patterns due to reflection of the probe beam from different interfaces.

  18. Studies on chemical bath deposited zinc sulphide thin films with special optical properties

    Energy Technology Data Exchange (ETDEWEB)

    Ladar, Maria [Faculty of Chemistry and Chemical Engineering, ' Babes-Bolyai' University, 400028 Cluj-Napoca (Romania); ' Raluca Ripan' Institute for Research in Chemistry, 30 Fantanele, 400294 Cluj-Napoca (Romania); Popovici, Elisabeth-Jeanne [' Raluca Ripan' Institute for Research in Chemistry, 30 Fantanele, 400294 Cluj-Napoca (Romania)]. E-mail: jennypopovici@yahoo.com; Baldea, Ioan [Faculty of Chemistry and Chemical Engineering, ' Babes-Bolyai' University, 400028 Cluj-Napoca (Romania); Grecu, Rodica [' Raluca Ripan' Institute for Research in Chemistry, 30 Fantanele, 400294 Cluj-Napoca (Romania); Indrea, Emil [National Institute for R and D of Isotopic and Molecular Technology, Donath 71-103, 400293 Cluj-Napoca (Romania)

    2007-05-31

    Adherent and uniform zinc sulphide thin films were deposited on optical glass platelets from chemical bath containing thiourea, zinc acetate, ammonia and sodium citrate. The samples, as they were prepared were investigated by UV-vis absorption/reflection spectroscopy, fluorescence spectroscopy and X-ray diffraction. The effects of growth conditions such as reagent concentration and deposition technique (mono- and multi-layer) on optical and structural properties of the ZnS thin films have been studied. The ability of ZnS films to exhibit luminescent properties has also been investigated.

  19. The Effect of Deposition Rate on Electrical, Optical and Structural Properties of ITO Thin Films

    Directory of Open Access Journals (Sweden)

    P. S. Raghupathi

    2005-01-01

    Full Text Available Indium tin oxide (ITO thin films have been prepared using the reactive evaporation technique on glass substrates in an oxygen atmosphere. It is found that the deposition rate plays prominent role in controlling the electrical and optical properties of the ITO thin films. Resistivity, electrical conductivity, activation energy, optical transmission and band gap energy were investigated. A transmittance value of more than 90% in the visible region of the spectrum and an electrical conductivity of 3x10–6 Ωm has been obtained with a deposition rate of 2 nm/min. XRD studies showed that the films are polycrystalline.

  20. Thin current sheets caused by plasma flow gradients in space plasma

    Science.gov (United States)

    Nickeler, D.; Wiegelmann, T.

    2011-12-01

    To understand complex space plasma systems like the solar wind-magnetosphere coupling, we need to have a good knowledge of the slowly evolving equilibrium state. The slow change of external constraints on the system (for example boundary conditions or other external parameters) lead in many cases to the formation of current sheets. These current sheets can trigger micro-instabilities, which cause resistivity on fluid scales. Consequently resistive instabilities like magnetic reconnection can occur and the systems evolves dynamically. Therefore such a picture of quasi-magneto-hydro-static changes can explain the quasy-static phase of many space plasma before an eruption occurs. Within this work we extend the theory by the inclusion of a nonlinear stationary plasma flows. Our analysis shows that stationary plasma flows with strong flow gradients (for example the solar wind magnetosphere coupling) can be responsible for the existence or generation of current sheets.

  1. Electromagnetic thin-wall model for simulations of plasma wall-touching kink and vertical modes

    Science.gov (United States)

    Zakharov, Leonid E.; Atanasiu, Calin V.; Lackner, Karl; Hoelzl, Matthias; Strumberger, Erika

    2015-12-01

    > The understanding of plasma disruptions in tokamaks and predictions of their effects require realistic simulations of electric current excitation in three-dimensional vessel structures by the plasma touching the walls. As discovered at JET in 1996 (Litunovski JET Internal Report contract no. JQ5/11961, 1995; Noll et al., Proceedings of the 19th Symposium on Fusion Technology, Lisbon (ed. C. Varandas & F. Serra), vol. 1, 1996, p. 751. Elsevier) the wall-touching kink modes are frequently excited during vertical displacement events and cause large sideways forces on the vacuum vessel which are difficult to withstand in large tokamaks. In disruptions, the sharing of electric current between the plasma and the wall plays an important role in plasma dynamics and determines the amplitude and localization of the sideways force (Riccardo et al., Nucl. Fusion, vol. 40, 2000, p. 1805; Riccardo & Walker, Plasma Phys. Control. Fusion, vol. 42, 2000, p. 29; Zakharov, Phys. Plasmas, vol. 15, 2008, 062507; Riccardo et al., Nucl. Fusion, vol. 49, 2009, 055012; Bachmann et al., Fusion Engng Des., vol. 86, 2011, pp. 1915-1919). This paper describes a flat triangle representation of the electric circuits of a thin conducting wall of arbitrary three-dimensional geometry. Implemented into the shell simulation code (SHL) and the source sink current code (SSC), this model is suitable for modelling the electric currents excited in the wall inductively and through current sharing with the plasma.

  2. Plasma treatment of polystyrene thin films affects more than the surface.

    Science.gov (United States)

    Calchera, Angela R; Curtis, Alexander D; Patterson, James E

    2012-07-25

    Plasma treatment of polymer materials introduces chemical functionalities and modifies the material to make the native hydrophobic surface more hydrophilic. It is generally assumed that this process only affects the surface of the material. We used vibrationally resonant sum-frequency generation spectroscopy to observe changes in the orientation of phenyl groups in polystyrene (PS) thin films on various substrates before and after plasma treatment. VR-SFG selectively probes regions of broken symmetry, such as surfaces, but can also detect the emergence of anisotropy. On dielectric substrates, such as fused silica, the spectroscopic peak corresponding to the symmetric stretching (ν2) mode of the phenyl rings was undetectable after plasma treatment, showing that surface phenyl rings were altered. This peak also diminished on conducting substrates, but the intensity of another peak corresponding to the same mode in a bulklike environment increased significantly, suggesting that plasma treatment induces partial ordering of the bulk polymer. This ordering is seen on conducting substrates even when the polymer is not directly exposed to the plasma. Annealing reverses these effects on the polystyrene bulk; however, the surface phenyl rings do not return to the orientation observed for untreated films. These results call into question the assumption that the effects of plasma treatment are limited to the free surface and opens up other possibilities for material modification with low-temperature plasmas.

  3. Optical bandgap of single- and multi-layered amorphous germanium ultra-thin films

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Pei; Zaslavsky, Alexander [Department of Physics and School of Engineering, Brown University, 182-184 Hope St., Providence, Rhode Island 02912 (United States); Longo, Paolo [Gatan, Inc., 5794 W Las Positas Blvd., Pleasanton, California 94588 (United States); Pacifici, Domenico, E-mail: Domenico-Pacifici@brown.edu [School of Engineering, Brown University, 184 Hope St., Providence, Rhode Island 02912 (United States)

    2016-01-07

    Accurate optical methods are required to determine the energy bandgap of amorphous semiconductors and elucidate the role of quantum confinement in nanometer-scale, ultra-thin absorbing layers. Here, we provide a critical comparison between well-established methods that are generally employed to determine the optical bandgap of thin-film amorphous semiconductors, starting from normal-incidence reflectance and transmittance measurements. First, we demonstrate that a more accurate estimate of the optical bandgap can be achieved by using a multiple-reflection interference model. We show that this model generates more reliable results compared to the widely accepted single-pass absorption method. Second, we compare two most representative methods (Tauc and Cody plots) that are extensively used to determine the optical bandgap of thin-film amorphous semiconductors starting from the extracted absorption coefficient. Analysis of the experimental absorption data acquired for ultra-thin amorphous germanium (a-Ge) layers demonstrates that the Cody model is able to provide a less ambiguous energy bandgap value. Finally, we apply our proposed method to experimentally determine the optical bandgap of a-Ge/SiO{sub 2} superlattices with single and multiple a-Ge layers down to 2 nm thickness.

  4. Optical bandgap of single- and multi-layered amorphous germanium ultra-thin films

    Science.gov (United States)

    Liu, Pei; Longo, Paolo; Zaslavsky, Alexander; Pacifici, Domenico

    2016-01-01

    Accurate optical methods are required to determine the energy bandgap of amorphous semiconductors and elucidate the role of quantum confinement in nanometer-scale, ultra-thin absorbing layers. Here, we provide a critical comparison between well-established methods that are generally employed to determine the optical bandgap of thin-film amorphous semiconductors, starting from normal-incidence reflectance and transmittance measurements. First, we demonstrate that a more accurate estimate of the optical bandgap can be achieved by using a multiple-reflection interference model. We show that this model generates more reliable results compared to the widely accepted single-pass absorption method. Second, we compare two most representative methods (Tauc and Cody plots) that are extensively used to determine the optical bandgap of thin-film amorphous semiconductors starting from the extracted absorption coefficient. Analysis of the experimental absorption data acquired for ultra-thin amorphous germanium (a-Ge) layers demonstrates that the Cody model is able to provide a less ambiguous energy bandgap value. Finally, we apply our proposed method to experimentally determine the optical bandgap of a-Ge/SiO2 superlattices with single and multiple a-Ge layers down to 2 nm thickness.

  5. Investigation in morphology and optical properties of electron beam gun evaporated nanostructured Bromoindium phthalocyanine thin films

    Science.gov (United States)

    Azim-Araghi, M. E.; Sahebi, R.

    2014-01-01

    Bromoindium phthalocyanine in thin film form was prepared by electron beam gun evaporation technique, using pre-cleaned polyborosilicate glass as substrate. 2D AFM image confirms that the surface of BrInPc thin film is granular with a grain size of 40-60 nm. 3D AFM image confirms that surface is homogeneous and its RMS roughness is 4.9 nm. The UV-VIS absorption spectrum showed two well-known absorption bands of the phthalocyanines, B and Q bands and characteristics Davydov splitting were observed. The optical transition determined to be direct allowed and the value of optical band gap was obtained. The value of Urbach energy was calculated. To investigation in the effect of thermal annealing on optical properties of BrInPc thin films, we annealed some thin films at 473 and 603 K for 1 h. As the result of thermal annealing we observed another absorption peak, named N-band, in absorption spectrum. A red shift observed in the position of B-band and Q-band peaks. There was not changing in optical transition mechanism. The value of optical band gap decreased and the Urbach energy increased as the result of thermal annealing.

  6. Plasma and Laser-Enhanced Deposition of Powders and Thin Films.

    Science.gov (United States)

    David, Moses

    The objective of this thesis has been the development of novel plasma and laser based techniques for the deposition and characterization of thin films and nano-scale powders. The different energy sources utilized for excitation and break -down of reactive species prior to deposition include an RF plasma discharge, an excimer laser and a CO _2 laser. Nanometer-scale (10-20 nm) powders and thin films of aluminum nitride (AlN) have been successfully deposited in a glow discharge by reacting trimethylaluminum and ammonia. Macroquantities (~800 mg/hr) of powder have been collected at the centers of two vortices around which the reactant gases swirl. Powders of AlN have large surface areas (85 m^2/g) and are free from oxygen contamination. Diamond-like-carbon (DLC) films have been deposited from ternary mixtures of butadiene, argon and hydrogen. DLC films have been etched in O _2 and CF_4/O _2 plasmas. The etching behavior was correlated with the deposition feed gas composition by combining the etch rate, bias voltage during deposition and the deposition rate into a new non-dimensional number. Two new processes for depositing copper films have been developed. The first technique involves the hydrogen plasma reduction of copper formate films and the second technique involves the reactive excimer laser ablation of copper formate. Particle forming plasmas have been characterized by measuring the light scattering intensity during the deposition of silicon nitride from silane/ammonia plasmas. Both spatial variations and transients during the plasma start -up and shut-off steps have been measured. The ultraviolet (vacuum ultraviolet and extreme ultraviolet) reflectance characteristics of AlN, DLC and SiC thin films has been measured. AlN and SiC films exhibit a relatively high (~20-40%) reflectance in the different regions of the ultraviolet spectrum. An improved algorithm has been developed for estimating thin film parameters such as thickness, refractive index, band-gap, and

  7. Linear and nonlinear optical properties of SrBi4Ti4O15 thin films

    Science.gov (United States)

    Rambabu, A.; Reddy, E. Sivanagi; Hamad, Syed; Raju, K. C. James; Rao, S. Venugopal

    2016-05-01

    Polycrystalline SrBi4Ti4O15 thin films with good morphology and layered perovskite structure were fabricated on fused silica substrates using r f magnetron sputtering system at various oxygen mixing percentages (25 and 50). The crystallite sizes of the particles are in 17-28 nm range. The Nonlinear optical properties were investigated by using Z-scan method at a wavelength of 800 nm with 2 ps duration pulses. The films exhibit the fast and giant optical nonlinearities having the two-photon absorption coefficient (β) with magnitude of 10-8-10-9 cm/W and the nonlinear refraction coefficient of ˜10-12 cm2/W. These results indicate SrBi4Ti4O15 thin films are promising candidates for applications in nonlinear optical and optical signal processing devices.

  8. Thin films from hydrophilic poly(N,N-dimethyl acrylamide) copolymers as optical indicators for humidity

    Science.gov (United States)

    Lazarova, K.; Todorova, L.; Christova, D.; Vasileva, M.; Georgiev, R.; Madjarova, V.; Babeva, T.

    2017-01-01

    In the present paper we study thin films from poly(N,N-dimethyl acrylamide)-poly(ethylene oxide) (PDMAA/PEO) copolymers of different composition and structure in order to implement them as sensitive media for optical indicators for humidity. PDMAA/PEO di- and triblock copolymers were synthesized via redox polymerization in aqueous media. Thin films were deposited on silicon substrates by spin coating method using polymers solutions with appropriate concentrations. Refractive index, extinction coefficient and thickness of the films are calculated from reflectance spectra of the films deposited on silicon substrates using non-linear curve fitting method. Sensing properties of the films were tested by films exposure to different humidity levels followed by in-situ monitoring of the changes in the optical properties. The influence of the polymer structure and postdeposition annealing on the optical and sensing properties of the films was investigated. The potential application of selected polymers for optical sensing of humidity were demonstrated and discussed.

  9. Influence of Bi doping on the electrical and optical properties of ZnO thin films

    Science.gov (United States)

    Abed, S.; Bougharraf, H.; Bouchouit, K.; Sofiani, Z.; Derkowska-Zielinska, B.; Aida, M. S.; Sahraoui, B.

    2015-09-01

    Transparent conducting ZnO doped Bi thin films were prepared on glass substrates by ultrasonic spray method. The influence of Bi doping concentration on the structural, optical and nonlinear optical properties of ZnO thin films was studied. The X-ray diffraction (XRD) analysis show that all studied films have a hexagonal wurtzite structure and are preferentially oriented along the c-axis from substrate surface. Optical transmittance measurements show that all samples have average 80% transparency in the visible light. Optical band gap values range between 3.14 and 3.28 eV. ZnO film with 3 wt% of Bi showed the highest electrical conductivity. In addition, the second and third order nonlinear susceptibilities were determined and their values have been calculated.

  10. Laser Induced Nonlinear Optical Properties of Zinc Oxide Thin Film Prepared by Sol-Gel Method

    Directory of Open Access Journals (Sweden)

    Vinay Kumari

    2011-01-01

    Full Text Available Optical nonlinearities of spin coated ZnO thin film have been investigated by using single beam Z-Scan technique in the visible region. X- ray diffraction shows that all films are oriented along the c-axis direction of the hexagonal crystal structure. The average optical transmittance of all films is higher than 80 %. The nonlinear optical parameters viz. nonlinear absorption coefficient (β, nonlinear index of refraction (η2, nonlinear susceptibility (χ3, have been estimated using nanosecond laser pulses of second harmonic of Nd:YAG Laser. The value of nonlinear absorption coefficient β is estimated to be greater than the already reported value. The films clearly exhibit a-ve value of nonlinear refraction at 532 nm which is attributed to the two photon absorption and free carrier absorption. The presence of RSA in ZnO thin films inferes that ZnO is a potential material for the development of optical limiter.

  11. Simulation of polyatomic discharges for thin film deposition processes in low-pressure plasma reactors

    Science.gov (United States)

    Bera, Kallol

    Comprehensive multi-dimensional self-consistent numerical fluid models for radio-frequency capacitively and inductively coupled methane discharges were developed to predict diamond-like-carbon thin film deposition/etching rate on the wafer. A numerical model of glow discharge provides insight on the physical phenomena in the discharge leading to better understanding and design of the reactor. The developed discharge models included detailed discharge physics, gas-phase chemistry and surface chemistry modeling. To understand the basic discharge phenomena, one- dimensional radio frequency capacitively coupled Ar plasma was simulated using a fluid model. The model was modified for methane plasma to predict the profiles of the plasma variables. The model was then extended to two- dimensional cylindrical coordinates to capture the effects of asymmetry of the reactor on the plasma variables. The necessary dc bias for the discharge was predicted such that the cycle-averaged current to the powered electrode was zero. A discharge chemistry model was also developed to predict various radical and neutral densities in the plasma, and their fluxes to the cathode. The species fluxes are used to predict film deposition rate and the properties of the deposited film. The model predictions of plasma density, self-generated de bias, cathode current and plasma potential compared well with the experimental results. A high density plasma with inductive coupling at low pressure was also considered. Separate rf bias and dc bias are applied to the substrate holder to modulate the ion energy. The present model simulates electron, ion and neutral transport, including detailed discharge and surface chemistry. The model has been implemented for methane discharge to obtain deposition/etching of thin carbon film on the wafer. To the author's knowledge, this is the first attempt to simulate capacitively and inductively coupled plasmas self-consistently for a depositing gas under the operating

  12. LOCO: Characterization of Phytoplankton in Thin Optical Layers

    Science.gov (United States)

    2008-01-01

    this process is that compatible gametes must be successful in finding each other in a dilute, watery environment. We have hypothesized that the...close proximity of cells in a dense thin layer should facilitate this process. Consistent with these ideas, male gamete formation, as well as auxospores...various stages of male gamete formation. CytoSense Evaluation. Our CytoSense scanning, in-line flow cytometer was specifically designed to study the

  13. Optical diagnostics for laser wakefields in plasma channels

    Science.gov (United States)

    Gaul, E. W.; Le Blanc, S. P.; Downer, M. C.

    1998-11-01

    Laser wakefield accelerators can excite large amplitude electrostatic fields (E >= 100 GV/m) which are potentially suitable for compact accelerators and advanced high energy colliders. An accurate diagnostic tool is necessary to test the physical effects in the wakefield predicted by theory and numerical simulations, and to have control over experiments. Frequency domain interferometry (FDI) (C. W. Siders et. al.), Phys. Rev. Lett. 76, 3570 (1995) has been developed in previous work. We experimentally demonstrate single-shot FDI as a sensitive diagnostic technique for probing laser wakefields. To generate wakefields longer than the diffraction limit, optical guiding of the laser pulse is necessary. An optical guide is formed by the hydrodynamic expansion of a cylindrical shock wave driven by a laser heated plasma, which is generated by laser pulse focused with an axicon lens (C. G. Durfee and H. M. Milchberg, Phys. Rev. Lett. 71, 2409 (1993)) to intensities of ~= 10^13 W/cm^2. These are too low to reach multi-photon ionization or significant collisional ionization in <= 1 atm helium. We preionize Helium gas with an electrical discharge for efficient inverse bremsstrahlung absorption of the laser pulse and formation of a plasma channel. Spatially resolved chirped pulse interferometry is used to measure the radial electron density profile of the channel.

  14. Growth of oxide thin films for optical gas sensor applications

    Energy Technology Data Exchange (ETDEWEB)

    Caiteanu, D. [Lasers Department, Institute of Atomic Physics, P.O. Box MG 36, 76900 Bucharest V (Romania); Gyoergy, E. [Lasers Department, Institute of Atomic Physics, P.O. Box MG 36, 76900 Bucharest V (Romania)]. E-mail: eniko@ifin.nipne.ro; Grigorescu, S. [Lasers Department, Institute of Atomic Physics, P.O. Box MG 36, 76900 Bucharest V (Romania); Mihailescu, I.N. [Lasers Department, Institute of Atomic Physics, P.O. Box MG 36, 76900 Bucharest V (Romania); Prodan, G. [University ' Ovidius' of Constanta, Mamaia Bd., 124, Constanta 900527 (Romania); Ciupina, V. [University ' Ovidius' of Constanta, Mamaia Bd., 124, Constanta 900527 (Romania)

    2006-04-30

    Tungsten trioxide and titanium dioxide thin films were synthesised by pulsed laser deposition. We used for irradiations of oxide targets an UV KrF* ({lambda} = 248 nm, {tau} {sub FWHM} {approx_equal} 20 ns, {nu} = 2 Hz) excimer laser source, at 2 J/cm{sup 2} incident fluence value. The experiments were performed in low oxygen pressure. The (0 0 1) SiO{sub 2} substrates were heated during the thin film deposition process at temperature values within the 300-500 deg. Crange. The structure and crystalline status of the obtained oxide thin films were investigated by high resolution transmission electron microscopy. Our analyses show that the films are composed by nanoparticles with average diameters from a few to a few tens of nm. Moreover, the films deposited at substrate temperatures higher than 300 deg. Care crystalline. The tungsten trioxide films consist of a mixture of triclinic and monoclinic phases, while the titanium dioxide films structure corresponds to the tetragonal anatase phase. The oxide films average transmittance in the visible-infrared spectral range is higher than 80%, which makes them suitable for sensor applications.

  15. A Study of Optical Parameters of Tin Sulphide Thin Films Using the Swanepoel Method

    Science.gov (United States)

    Ragina, A. J.; Murali, K. V.; Preetha, K. C.; Deepa, K.; Remadevi, T. L.

    2011-10-01

    The knowledge of the optical parameters of thin films is important for optics and optoelectronics. In the present work, tin sulphide thin films were deposited on glass substrates by chemical bath deposition method. The as grown films were brown in color and highly adherent to the substrate. The films were characterized by X-ray diffraction (XRD), scanning electron microscopy and spectrophotometric measurements. XRD patterns showed that the films developed were orthorhombic structure. SEM images of tin sulphide thin films confirmed the formation of nanowires. Absorption spectra revealed medium absorption in the visible region and a gradual decrease with higher wavelength. The transmittance of the as-synthesized films is about 50% in the wavelength range 600-1000 nm. The methodological framework of the Swanepoel's method for the spectrophotometric determination of optical parameters of tin sulphide thin films using transmittance data was discussed. The Swanepoel's method is found to be applicable for thin films when measured transmittance spectra have at least one minimum and one maximum. By analyzing the transmission curve, the refractive index and the thickness of the film were evaluated. The energy band gaps are also reported. The optical band gap is direct with a value of 1.79 eV. The values of the optical band gap energy and thickness of the film calculated by Swanepoel's method were compared with that obtained from absorption spectra and cross sectional SEM photographs respectively. These properties demonstrated that tin sulphide thin films could be used as an absorber layer in the fabrication of heterojunction solar cells.

  16. Engineering of the band gap and optical properties of thin films of yttrium hydride

    Energy Technology Data Exchange (ETDEWEB)

    You, Chang Chuan; Mongstad, Trygve; Maehlen, Jan Petter; Karazhanov, Smagul, E-mail: smagulk@ife.no [Institute for Energy Technology, P.O. Box 40, NO-2027 Kjeller (Norway)

    2014-07-21

    Thin films of oxygen-containing yttrium hydride show photochromic effect at room temperature. In this work, we have studied structural and optical properties of the films deposited at different deposition pressures, discovering the possibility of engineering the optical band gap by variation of the oxygen content. In sum, the transparency of the films and the wavelength range of photons triggering the photochromic effect can be controlled by variation of the deposition pressure.

  17. Magneto-optical and magnetic properties in a Co/Pd multilayered thin film

    Science.gov (United States)

    Nwokoye, Chidubem A.; Bennett, Lawrence H.; Della Torre, Edward; Ghahremani, Mohammadreza; Narducci, Frank A.

    2017-01-01

    The paper describes investigation of ferromagnetism at low temperatures. We explored the magneto-optical properties, influenced by photon-magnon interactions, of a ferromagnetic Co/Pd multilayered thin film below and above the magnon Bose-Einstein Condensation (BEC) temperature. Analyses of SQUID and MOKE low temperature experimental results reveal a noticeable phase transition in both magnetic and magneto-optical properties of the material at the BEC temperature.

  18. Optimization of time on CF{sub 4}/O{sub 2} etchant for inductive couple plasma reactive ion etching of TiO{sub 2} thin film

    Energy Technology Data Exchange (ETDEWEB)

    Adzhri, R., E-mail: adzhri@gmail.com; Fathil, M. F. M.; Ruslinda, A. R.; Gopinath, Subash C. B.; Voon, C. H.; Foo, K. L.; Nuzaihan, M. N. M.; Azman, A. H.; Zaki, M. [Institute of Nano Electronic Engineering (INEE), Universiti Malaysia Perlis (UniMAP), Perlis (Malaysia); Arshad, M. K. Md., E-mail: mohd.khairuddin@unimap.edu.my; Hashim, U.; Ayub, R. M. [Institute of Nano Electronic Engineering (INEE), Universiti Malaysia Perlis (UniMAP), Perlis (Malaysia); School of Microelectronic Engineering, Universiti Malaysia Perlis (UniMAP), Perlis (Malaysia)

    2016-07-06

    In this work, we investigate the optimum etching of titanium dioxide (TiO{sub 2}) using inductive couple plasma reactive ion etching (ICP-RIE) on our fabricated devices. By using a combination of CF{sub 4}/O{sub 2} gases as plasma etchant with ratio of 3:1, three samples of TiO{sub 2} thin film were etched with different time duration of 10 s, 15 s and 20 s. The ion bombardment of CF{sub 4} gases with plasma enhancement by O{sub 2} gas able to break the oxide bond of TiO{sub 2} and allow anisotropic etch profile with maximum etch rate of 18.6 nm/s. The sample was characterized by using optical profilometer to determine the depth of etched area and scanning electron microscopy (SEM) for etch profile characterization.

  19. Optical and electrical properties of boron doped diamond thin conductive films deposited on fused silica glass substrates

    Science.gov (United States)

    Ficek, M.; Sobaszek, M.; Gnyba, M.; Ryl, J.; Gołuński, Ł.; Smietana, M.; Jasiński, J.; Caban, P.; Bogdanowicz, R.

    2016-11-01

    This paper presents boron-doped diamond (BDD) film as a conductive coating for optical and electronic purposes. Seeding and growth processes of thin diamond films on fused silica have been investigated. Growth processes of thin diamond films on fused silica were investigated at various boron doping level and methane admixture. Two step pre-treatment procedure of fused silica substrate was applied to achieve high seeding density. First, the substrates undergo the hydrogen plasma treatment then spin-coating seeding using a dispersion consisting of detonation nanodiamond in dimethyl sulfoxide with polyvinyl alcohol was applied. Such an approach results in seeding density of 2 × 1010 cm-2. The scanning electron microscopy images showed homogenous, continuous and polycrystalline surface morphology with minimal grain size of 200 nm for highly boron doped films. The sp3/sp2 ratio was calculated using Raman spectra deconvolution method. A high refractive index (range of 2.0-2.4 @550 nm) was achieved for BDD films deposited at 500 °C. The values of extinction coefficient were below 0.1 at λ = 550 nm, indicating low absorption of the film. The fabricated BDD thin films displayed resistivity below 48 Ohm cm and transmittance over 60% in the visible wavelength range.

  20. An Uneven Illumination Correction Algorithm for Optical Remote Sensing Images Covered with Thin Clouds

    Directory of Open Access Journals (Sweden)

    Xiaole Shen

    2015-09-01

    Full Text Available The uneven illumination phenomenon caused by thin clouds will reduce the quality of remote sensing images, and bring adverse effects to the image interpretation. To remove the effect of thin clouds on images, an uneven illumination correction can be applied. In this paper, an effective uneven illumination correction algorithm is proposed to remove the effect of thin clouds and to restore the ground information of the optical remote sensing image. The imaging model of remote sensing images covered by thin clouds is analyzed. Due to the transmission attenuation, reflection, and scattering, the thin cloud cover usually increases region brightness and reduces saturation and contrast of the image. As a result, a wavelet domain enhancement is performed for the image in Hue-Saturation-Value (HSV color space. We use images with thin clouds in Wuhan area captured by QuickBird and ZiYuan-3 (ZY-3 satellites for experiments. Three traditional uneven illumination correction algorithms, i.e., multi-scale Retinex (MSR algorithm, homomorphic filtering (HF-based algorithm, and wavelet transform-based MASK (WT-MASK algorithm are performed for comparison. Five indicators, i.e., mean value, standard deviation, information entropy, average gradient, and hue deviation index (HDI are used to analyze the effect of the algorithms. The experimental results show that the proposed algorithm can effectively eliminate the influences of thin clouds and restore the real color of ground objects under thin clouds.

  1. Modifications in Structural, Electrical, Electronic and Mechanical Properties of Titanium Thin Films under different Gas Plasmas

    Science.gov (United States)

    Singh, Omveer; Dahiya, Raj P.; Malik, Hitendra K.

    2015-09-01

    In the recent past, Titanium thin films can be grown over different substrates such as silicon, glass and quartz by using versatile deposition techniques DC, RF sputtering, electronic beam and thermal evaporation etc. The grown films are then exposed in different gas environments for individual application. It has been found that Titanium nitride exhibits good chemical stability, mechanical and electrical properties. To investigate these properties in titanium nitride thin films, we have developed a new approach hot cathode arc discharge plasma system. By using this technique, we can measure plasma and nitriding parameters independently. In the present work, we have investigated gases mixture (Nitrogen, Argon and Hydrogen) effect on the structural, mechanical, electrical and electronic properties in plasma system. We have used 100% N2, 50% N2 + 50% Ar and 50% N2 + 50% H2 gases ratio for plasma nitriding. Structural and electronic structure properties are measured from X-ray diffractions (XRD) and X-ray photoelectron spectroscopy (XPS) respectively. The surface morphology of these films were measured using Atomic Force Microscopy (AFM) and the nano-indentation mode is used to find out the hardness of the samples. Government of India.

  2. Hybrid formulation of radiation transport in optically thick divertor plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Rosato, J.; Marandet, Y.; Bufferand, H.; Stamm, R. [PIIM, UMR 7345 Aix-Marseille Universite / CNRS, Centre de St-Jerome, Marseille (France); Reiter, D. [IEK-4 Plasmaphysik, Forschungszentrum Juelich GmbH, Juelich (Germany)

    2016-08-15

    Kinetic Monte Carlo simulations of coupled atom-radiation transport in optically thick divertor plasmas can be computationally very demanding, in particular in ITER relevant conditions or even larger devices, e.g. for power plant divertor studies. At high (∝ 10{sup 15} cm{sup -3}) atomic densities, it can be shown that sufficiently large divertors behave in certain areas like a black body near the first resonance line of hydrogen (Lyman α). This suggests that, at least in part, the use of continuum model (radiation hydrodynamics) can be sufficiently accurate, while being less time consuming. In this work, we report on the development of a hybrid model devoted to switch automatically between a kinetic and a continuum description according to the plasma conditions. Calculations of the photo-excitation rate in a homogeneous slab are performed as an illustration. The outlined hybrid concept might be also applicable to neutral atom transport, due to mathematical analogy of transport equations for neutrals and radiation. (copyright 2016 The Authors. Contributions to Plasma Physics published by Wiley-VCH Verlag GmbH and Co. KGaA Weinheim. This)

  3. Optical emission spectroscopy of argon and hydrogen-containing plasmas

    Science.gov (United States)

    Siepa, Sarah; Danko, Stephan; Tsankov, Tsanko V.; Mussenbrock, Thomas; Czarnetzki, Uwe

    2015-09-01

    Optical emission spectroscopy (OES) on neutral argon is applied to investigate argon, hydrogen and hydrogen-silane plasmas. The spectra are analyzed using an extensive collisional-radiative model (CRM), from which the electron density and the electron temperature (or mean energy) can be calculated. The CRM also yields insight into the importance of different excited species and kinetic processes. The OES measurements are performed on pure argon plasmas at intermediate pressure. Besides, hydrogen and hydrogen-silane plasmas are investigated using argon as a trace gas. Especially for the gas mixture discharges, CRMs for low and high pressure differ substantially. The commonly used line-ratio technique is found to lose its sensitivity for gas mixture discharges at higher pressure. A solution using absolutely calibrated line intensities is proposed. The effect of radiation trapping and the shape of the electron energy distribution function on the results are discussed in detail, as they have been found to significantly influence the results. This work was supported by the Ruhr University Research School PLUS, funded by Germany's Excellence Initiative [DFG GSC 98/3].

  4. Optical Properties of Magnetron sputtered Nickel Thin Films

    Science.gov (United States)

    Twagirayezu, Fidele; Geerts, Wilhelmus J.; Cui, Yubo

    2015-03-01

    The study of optical properties of Nickel (Ni) is important, given the pivotal role it plays in the semiconductor and nano-electronics technology. Ni films were made by DC and RF magnetron sputtering in an ATC Orion sputtering system of AJA on various substrates. The optical properties were studied ex situ by variable angle spectroscopic (220-1000 nm) ellipsometry at room temperature. The data were modeled and analyzed using the Woollam CompleteEase Software fitting ellipsometric and transmission data. Films sputtered at low pressure have optical properties similar to that of Palik. Films sputtered at higher pressure however have a lower refraction index and extinction coefficient. It is expected from our results that the density of the sputtered films can be determined from the ellipsometric quantities. Our experiments also revealed that Ni is susceptible to a slow oxidation changing its optical properties over the course of several weeks. The optical properties of the native oxide differ from those of reactive sputtered NiO similar as found by. Furthermore the oxidation process of our samples is characterized by at least two different time constants.

  5. Multiple oscillator models for the optical constants of polycrystalline zinc oxide thin films over a wide wavelength range

    Energy Technology Data Exchange (ETDEWEB)

    Khoshman, J.M., E-mail: khoshman@ahu.edu.jo [Department of Physics, Al-Hussein Bin Talal University, Maan 71111 (Jordan); College of Engineering, University of Dammam, Dammam 31451 (Saudi Arabia); Hilfiker, J.N. [J.A. Woollam Company, 645 M Street, Suite 102, Lincoln, NE 68508 (United States); Tabet, N. [Physics Department, Center of Research Excellence in Renewable Energy, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Kordesch, M.E. [Department of Physics and Astronomy, Ohio University, Athens, OH 45701 (United States)

    2014-07-01

    Zinc oxide (ZnO) films were prepared on Si(1 1 1) and quartz substrates using RF-magnetron sputtering in N₂ plasma at room temperature. From the X-ray diffraction observations, it was found that all films are polycrystalline with a preferred orientation of (1 0 1). X ray photoelectron spectroscopy was used to analyze the chemical composition of the films by observing the behavior of the Zn2p3, O1s, N1s, and C1s lines. The thicknesses and optical constants of the ZnO thin films were determined using variable angle spectroscopic ellipsometry through the Genosc™ Herzinger–Johs parameterized semiconductor oscillator functions and multiple Gaussian oscillator models. Combining multiple oscillator types provided a very flexible approach to fitting optical constants over a wavelength range 190–1400 nm while simultaneously enforcing Kramers–Kronig consistency in the fitted ellipsometric parameters. Refractive indices of the films were determined to be in the range 1.68–1.93 and extinction coefficients in the range 4.56 × 10⁻⁶–0.23. A direct bandgap of 3.38 ± 0.03 eV was calculated from the extinction coefficient. Low temperature photoluminescence studies of the films exhibited one prominent peak at 3.41 eV. The equality of the ZnO thin films was obtained through the depolarization measurements.

  6. Variation in the structure and optical properties of polymorphous silicon thin films using dichlorosilane as silicon precursor

    Energy Technology Data Exchange (ETDEWEB)

    Remolina, A.; Hamui, L.; Monroy, B.M.; Garcia-Sanchez, M.F.; Santana, G. [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, AP 70-360, Cd. Universitaria, Coyoacan, C. P. 04510, Mexico D. F. (Mexico); Ponce, A. [Centro de Investigacion en Quimica Aplicada, Blvd. Enrique Reyna Hermosillo 140, C. P. 25290, Saltillo, Coahuila (Mexico); Picquart, M. [Departamento de Fisica, Universidad Autonoma Metropolitana, AP 55-534, Av. Sn Rafael Atlixco 186, Col. Vicentina, Iztapalapa, C.P. 09340, Mexico D. F. (Mexico)

    2011-03-15

    Polymorphous silicon thin films were obtained by plasma enhanced chemical vapor deposition using dichlorosilane as silicon precursor. The RF power and the dichlorosilane to hydrogen flow rate ratio were varied to obtain different crystalline fractions and average sizes of silicon nanocrystals embedded in the amorphous silicon matrix. Microscopy images confirmed the existence of nanocrystallites with averages sizes between 2 and 6 nm. Broader size distributions were obtained with increasing RF power. Raman results confirmed that different nanocrystalline fractions (from 12% to 54%) can be achieved in these films by regulating the selected growth parameters. The optical band gap calculated by the Tauc model from UV-visible transmittance measurements varies between 1.8 to 2.3 eV. The relationship between the optical properties is discussed in terms of the different nanostructures of the samples. Depending on their absorption properties and effective band gap, these materials can be suitable for application in thin film solar cell devices (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. Formation of quasiperiodic bimetal thin films with controlled optical and electrical properties

    Science.gov (United States)

    Arakelian, S.; Vartanyan, T.; Istratov, A.; Kutrovskaya, S.; Kucherik, A.; Itina, T.; Osipov, A.

    2016-04-01

    Synthesis of transparent conductive coatings is a promising direction of modern nanotechnological research. Thin nanostructured noble-metallic films demonstrate nonlinear optical effects in visible spectral range because of their plasmonic properties [1]. In addition, optical characteristics of these thin films strongly depend on the period of the formed surface structures [2]. If the distance between deposited particles almost equals their sizes, the optical properties of the randomly deposited structures may considerably differ from these for periodical structures [3]. In this work, we have studied the degree of the morphology influence (particle diameter in the colloid, the distance between the deposited particles, the number of layers etc.) on the optical and electrical properties of the deposited thin film of bimetallic gold and silver clusters. In this work we used CW-laser with moderate intensity in liquid (water or ethanol) for synthesis nanoparticles of noble metals. For the formation of quasi-periodically arranged clusters, particle deposition from the colloidal systems is used. The optical properties of the deposited bimetallic films are shown to change as a function of composition and geometry in agreement with the modeling of the optical properties.

  8. INFLUENCE OF ALUMINUM CONCENTRATION ON THE ELECTRICAL AND OPTICAL PROPERTIES OF ZnO THIN FILMS

    Directory of Open Access Journals (Sweden)

    Ebru GÜNGÖR

    2016-10-01

    Full Text Available Al:ZnO thin films having with different Al concentrations were deposited on glass substrates by a sol-gel technique. The effects of Al doping on the structural, optical and electrical properties of Al:ZnO were investigated using with XRD, optical transmittance and sheet resistance measurements. The concentration of zinc acetate was 0.1 M. Al content in the starting solution was varied from 0 to 20% as the molarity range. Optical transmittance spectra of the films in the form of Film/Glass were used to determine the film thickness and optical band gaps. The optical transmissions of Al:ZnO thin films were higher than 80% in the visible and near infrared region. The optical band gaps of Al:ZnO films decrease with increase of Al content. In order to obtain the average sheet resistance of the films the current and voltage through the probes have been measured for five different position by four-point probe method. The results showed that the sheet resistances of Al:ZnO thin films increased with the Al concentration. Considering the film thickness and geometric factor, the electrical resistivity values were computed. It was observed that the sheet resistance of AZO films up to 10% molarity of Al in the starting solution increased.

  9. Niobium thin film coating on a 500-MHz copper cavity by plasma deposition

    Energy Technology Data Exchange (ETDEWEB)

    Haipeng Wang; Genfa Wu; H. Phillips; Robert Rimmer; Anne-Marie Valente; Andy Wu

    2005-05-16

    A system using an Electron Cyclotron Resonance (ECR) plasma source for the deposition of a thin niobium film inside a copper cavity for superconducting accelerator applications has been designed and is being constructed. The system uses a 500-MHz copper cavity as both substrate and vacuum chamber. The ECR plasma will be created to produce direct niobium ion deposition. The central cylindrical grid is DC biased to control the deposition energy. This paper describes the design of several subcomponents including the vacuum chamber, RF supply, biasing grid and magnet coils. Operational parameters are compared between an operating sample deposition system and this system. Engineering work progress toward the first plasma creation will be reported here.

  10. Optical properties of nitrogen-doped graphene thin films probed by spectroscopic ellipsometry

    Energy Technology Data Exchange (ETDEWEB)

    Shen, C.C. [Department of Physics, National Taiwan Normal University, Taipei 11677, Taiwan (China); Tseng, C.C.; Lin, C.T.; Li, L.J. [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China); Liu, H.L., E-mail: hliu@ntnu.edu.tw [Department of Physics, National Taiwan Normal University, Taipei 11677, Taiwan (China)

    2014-11-28

    Nitrogen-doped graphene thin films were prepared by either chemical vapor deposition (CVD) or electrochemical exfoliation (ECE). Their optical properties were determined in the spectral region of 0.73–6.42 eV and at temperatures between 200 and 350 K by spectroscopic ellipsometry. The parameters of the dispersive structures were derived by numerical fitting of the experimental data to the stacked layer model. The optical absorption spectrum of the CVD-grown thin films is characterized by an asymmetric Fano resonance in the ultraviolet frequency region. In contrast, the line shape of the ECE-grown thin films displays less asymmetric. The excitonic resonance of the nitrogen-doped thin films is overall blue shifted by ∼ 0.2–0.3 eV compared with that of undoped analog. We interpret these results in terms of the exothermic nature of triazine molecule adsorption due to binding to graphene's surface via electron rich nitrogen. - Highlights: • Optical properties of N-doped graphene films determined by spectroscopic ellipsometry • Fano resonance in the ultraviolet frequency region of all graphene film absorption spectra • Blueshift in the excitonic resonance of N-doped graphene thin films is observed.

  11. Optical absorbers based on strong interference in ultra-thin films

    CERN Document Server

    Kats, Mikhail A

    2016-01-01

    Optical absorbers find uses in a wide array of applications across the electromagnetic spectrum, including photovoltaic and photochemical cells, photodetectors, optical filters, stealth technology, and thermal light sources. Recent efforts have sought to reduce the footprint of optical absorbers, conventionally based on graded structures or Fabry-Perot-type cavities, by using the emerging concepts of plasmonics, metamaterials, and metasurfaces. Unfortunately, these new absorber designs require patterning on subwavelength length scales, and are therefore impractical for many large-scale optical and optoelectronic devices. In this article, we summarize recent progress in the development of optical absorbers based on lossy films with thicknesses significantly smaller than the incident optical wavelength. These structures have a small footprint and require no nanoscale patterning. We outline the theoretical foundation of these absorbers based on "ultra-thin-film interference", including the concepts of loss-induc...

  12. Combinatorial plasma polymerization approach to produce thin films for testing cell proliferation.

    Science.gov (United States)

    Antonini, V; Torrengo, S; Marocchi, L; Minati, L; Dalla Serra, M; Bao, G; Speranza, G

    2014-01-01

    Plasma enhanced physical vapor depositions are extensively used to fabricate substrates for cell culture applications. One peculiarity of the plasma processes is the possibility to deposit thin films with reproducible chemical and physical properties. In the present work, a combinatorial plasma polymerization process was used to deposit thin carbon based films to promote cell adhesion, in the interest of testing cell proliferation as a function of the substrate chemical properties. Peculiarity of the combinatorial approach is the possibility to produce in just one deposition experiment, a set of surfaces of varying chemical moieties by changing the precursor composition. A full characterization of the chemical, physical and thermodynamic properties was performed for each set of the synthesized surfaces. X-ray photoelectron spectroscopy was used to measure the concentration of carboxyl, hydroxyl and amine functional groups on the substrate surfaces. A perfect linear trend between polar groups' density and precursors' concentration was found. Further analyses reveled that also contact angles and the correspondent surface energies of all deposited thin films are linearly dependent on the precursor concentration. To test the influence of the surface composition on the cell adhesion and proliferation, two cancer cell lines were utilized. The cell viability was assessed after 24 h and 48 h of cell culture. Experiments show that we are able to control the cell adhesion and proliferation by properly changing the thin film deposition conditions i.e. the concentration and the kind of chemical moiety on the substrate surface. The results also highlight that physical and chemical factors of biomaterial surface, including surface hydrophobicity and free energy, chemical composition, and topography, can altered cell attachment.

  13. Nonlinear Optical Parameters of Magnetoactive Semiconductor-Plasmas

    Science.gov (United States)

    Singh, M.; Joseph, D.; Duhan, S.

    The nonlinear optical parameters (absorption coefficient and refractive index) of semiconductor-plasmas subjected to a transverse magnetic field have been investigated analytically. By employing the coupled-mode scheme, an expression of third-order optical susceptibility and resultant nonlinear absorption and refractive index of the medium are obtained. The analysis has been applied to both cases, viz., centrosymmetric (β = 0) and noncentrosymmetric (β ≠ 0) in the presence of magnetic field. The numerical estimates are made for InSb crystal at liquid nitrogen temperature duly irradiated by a 10-nanosecond pulsed 10.6 μm CO2 laser. The influence of doping concentration and magnetic field on both the nonlinear absorption and refractive index has been explored, and the results are found to be well in agreement with theory and experiment. Analysis further establishes that absorption coefficient and refractive index can be controlled with precision in semiconductors by the proper selection of doping concentration and an external magnetic field, and hence these media may be used for fabrication of fast cubic nonlinear optical devices under off-resonant transition regime.

  14. Electrical, electronic and optical properties of amorphous indium zinc tin oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Denny, Yus Rama [Department of Physics, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Department of Electrical Engineering, University of Sultan Ageng Tirtayasa, Banten, Serang, 42435 (Indonesia); Lee, Kangil; Seo, Soonjoo; Oh, Suhk Kun [Department of Physics, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Kang, Hee Jae, E-mail: hjkang@cbu.ac.kr [Department of Physics, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Yang, Dong Seok [Department of Physics Education, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Heo, Sung; Chung, Jae Gwan; Lee, Jae Cheol [Analytical Engineering Center, Samsung Advanced Institute of Technology, Suwon 440-600 (Korea, Republic of)

    2014-10-01

    Highlights: • The electronic property of indium zinc tin oxide thin films was investigated by using XPS and REELS. • The band gap varied with different In/Zn/Sn compositions. • The EXAFS results showed that the smaller Zn–Zn separation distance led to higher electron mobility. • The Sn/Zn composition ratio played a crucial role in improving the electrical properties of a-IZTO thin films. - Abstract: The electrical and optical properties of amorphous indium zinc tin oxide (a-IZTO) thin films were examined as a function of chemical composition. Effects of Sn/Zn composition ratio and In content on the electrical and optical properties of a-IZTO thin films are discussed. The electron mobility of thin film transistors with higher Sn/Zn composition ratio was dramatically improved due to a shorter zinc–zinc separation distance. The thin film transistor with the composition of In:Zn:Sn = 20:48:32 exhibits a high mobility of 30.6 cm{sup 2} V{sup −1} s{sup −1} and a high on–off current ratio of 10{sup 9}.

  15. Characterization of delafossite-CuCrO{sub 2} thin films prepared by post-annealing using an atmospheric pressure plasma torch

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hong-Ying, E-mail: hychen@cc.kuas.edu.tw [Department of Chemical and Materials Engineering, National Kaohsiung University of Applied Sciences, 415 Chiken Kuang Road, Kaohsiung 807, Taiwan, ROC (China); Yang, Wei-Jung; Chang, Kuei-Ping [Department of Chemical and Materials Engineering, National Kaohsiung University of Applied Sciences, 415 Chiken Kuang Road, Kaohsiung 807, Taiwan, ROC (China)

    2012-09-01

    Highlights: Black-Right-Pointing-Pointer Dealfossite-CuCrO{sub 2} thin film was prepared using sol-gel processing and post-annealing with an atmospheric pressure plasma torch. Black-Right-Pointing-Pointer X-ray diffraction pattern shows pure delafossite-CuCrO{sub 2} thin films can be obtained. Black-Right-Pointing-Pointer The average transmittance of the film was 66% in the visible region and the direct optical bandgap was 3.08 eV. Black-Right-Pointing-Pointer The electrical conductivity of the film was 2.7 Multiplication-Sign 10{sup -2} Scm{sup -1} with the carrier concentration of 2.8 Multiplication-Sign 10{sup 13} cm{sup -3}. - Abstract: This study reports the preparation of delafossite-CuCrO{sub 2} thin films were prepared on quartz substrates using sol-gel processing and post-annealing with an atmospheric pressure plasma torch. The films were first deposited on a quartz substrate by spin coating. The specimens were then annealed at 500 Degree-Sign C in air and post-annealed with an atmospheric pressure plasma torch with N{sub 2}-5% O{sub 2} at 650 Degree-Sign C for 20 min. The specimens annealed in air exhibited CuO and CuCr{sub 2}O{sub 4} phases. Post-annealing using an atmospheric pressure plasma torch obtained the pure CuCrO{sub 2} (delafossite, R3{sup Macron }m) phase. The binding energies of the Cu-2p{sub 3/2} and Cr-2p{sub 3/2} peaks of the CuCrO{sub 2} thin films were centered at 932.1 {+-} 0.2 eV and 576.1 {+-} 0.2 eV, which revealed the valence state of Cu{sup +} and Cr{sup 3+} in the films. The chemical composition of CuCrO{sub 2} thin films was close to the stoichiometry. As the CuCrO{sub 2} phase formed, the film surface began to exhibit agglomerate features and the cross-sectional morphology showed an equiaxed grain feature. The average transmittance of CuCrO{sub 2} thin films was approximately 66% in the visible region. The direct optical bandgap of CuCrO{sub 2} thin films was 3.08 eV, which is consistent with reported data in the literature. The

  16. Large Optical Nonlinearity of Surface Plasmon Modes on Thin Gold Films

    DEFF Research Database (Denmark)

    Huck, Alexander; Witthaut, Dirk; Kumar, Shailesh

    2013-01-01

    We investigate the optical nonlinear effects of a long-range surface plasmon polariton mode propagating on a thin gold film. These effects may play a key role in the design of future nanophotonic circuits as they allow for the realization of active plasmonic elements. We demonstrate a significant...

  17. Structural, optical, and electrical properties of MgyTi1-yHx thin films

    NARCIS (Netherlands)

    Borsa, D. M.; Gremaud, R.; Baldi, A.; Schreuders, H.; Rector, J. H.; Kooi, B.; Notten, P. H. L.; Dam, B.; Griessen, R.

    The structural, optical, and electrical transformations induced by hydrogen absorption and/or desorption in Mg-Ti thin films prepared by co-sputtering of Mg and Ti are investigated. Highly reflective in the metallic state, the films become highly absorbing upon H absorption. The

  18. Optical anisotropy, molecular orientations, and internal stresses in thin sulfonated poly(ether ether ketone) films

    NARCIS (Netherlands)

    Koziara, Beata; Nijmeijer, Dorothea C.; Benes, Nieck Edwin

    2015-01-01

    The thickness, the refractive index, and the optical anisotropy of thin sulfonated poly(ether ether ketone) films, prepared by spin-coating or solvent deposition, have been investigated with spectroscopic ellipsometry. For not too high polymer concentrations (B5 wt%) and not too low spin speeds

  19. Optical anisotropy, molecular orientations, and internal stresses in thin sulfonated poly(ether ether ketone) films

    NARCIS (Netherlands)

    Koziara, B.T.; Nijmeijer, D.C.; Benes, N.E.

    2015-01-01

    The thickness, the refractive index, and the optical anisotropy of thin sulfonated poly(ether ether ketone) films, prepared by spin-coating or solvent deposition, have been investigated with spectroscopic ellipsometry. For not too high polymer concentrations (B5 wt%) and not too low spin speeds (C20

  20. Optimization of Ta2O5 optical thin film deposited by radio frequency magnetron sputtering.

    Science.gov (United States)

    Shakoury, R; Willey, Ronald R

    2016-07-10

    Radio frequency magnetron sputtering has been used here to find the parameters at which to deposit Ta2O5 optical thin films with negligible absorption in the visible spectrum. The design of experiment methodology was employed to minimize the number of experiments needed to find the optimal results. Two independent approaches were used to determine the index of refraction n and k values.

  1. Structural, optical, and electrical properties of MgyTi1-yHx thin films

    NARCIS (Netherlands)

    Borsa, D. M.; Gremaud, R.; Baldi, A.; Schreuders, H.; Rector, J. H.; Kooi, B.; Notten, P. H. L.; Dam, B.; Griessen, R.

    2007-01-01

    The structural, optical, and electrical transformations induced by hydrogen absorption and/or desorption in Mg-Ti thin films prepared by co-sputtering of Mg and Ti are investigated. Highly reflective in the metallic state, the films become highly absorbing upon H absorption. The reflector-to-absorbe

  2. Ultrafast terahertz conductivity and transient optical absorption spectroscopy of silicon nanocrystal thin films

    DEFF Research Database (Denmark)

    Titova, Lyubov V.; Harthy, Rahma Al; Cooke, David

    We use time-resolved THz spectroscopy and transient optical absorption spectroscopy as two complementary techniques to study ultrafast carrier dynamics in silicon nanocrystal thin films. We find that the photoconductive dynamics in these materials is dominated by interface trapping, and we observe...... several different relaxation mechanisms for photoexcited carriers...

  3. Optical properties on thermally evaporated and heat-treated disodium phthalocyanine derivative thin films

    Indian Academy of Sciences (India)

    M E Sánchez-Vergara; M Rivera; R A Torres-García; C O Perez-Baeza; E A Loza-Neri

    2014-08-01

    Thin films were grown on quartz substrates and crystalline silicon wafers using disodium phthalocyanine and the organic ligands 2,6-diaminoanthraquinone, 2,6-dihydroxianthraquinone and its potassium derivative salt. The surface morphology of these films was analysed by atomic force microscopy (AFM) and scanning electron microscopy (SEM). IR spectroscopy was employed in order to investigate possible changes of the intra-molecular bonds between the powder compounds and thin films. The optical parameters have been investigated using spectrophotometric measurements of absorbance in the wavelength range of 200–1100 nm and the effects of post-deposition heat treatment were analysed. The absorption spectra recorded in the UV–Vis region for the deposited samples showed two bands, namely the Q and Soret bands. The absorption coefficient in the absorption region reveals non-direct transitions. In addition, the optical gap dependence upon the thickness of these thin films was evaluated.

  4. Investigations of electrical and optical properties of functional TCO thin films

    Directory of Open Access Journals (Sweden)

    Domaradzki Jarosław

    2015-06-01

    Full Text Available Transparent conducting oxide (TCO films of indium-tin-oxide were evaporated on the surface of silicon wafers after phosphorous diffusion and on the reference glass substrates. The influence of deposition process parameters (electron beam current, oxygen flow and the substrate temperature on optical and electrical properties of evaporated thin films were investigated by means of resistivity measurements and optical spectrophotometry. The performance of prepared thin films was judged by calculated figure of merit and the best result was obtained for the sample deposited on the substrate heated to the 100 °C and then removed from the deposition chamber and annealed in an air for 5 minutes at 400 °C. Refractive index and extinction coefficient were evaluated based on measured transmission spectra and used for designing of antireflection coating for solar cell. The obtained results showed that prepared TCO thin films are promising as a part of counter electrode in crystalline silicon solar cell construction.

  5. Effects of O2 plasma post-treatment on ZnO: Ga thin films grown by H2O-thermal ALD

    Science.gov (United States)

    Lee, Yueh-Lin; Chuang, Jia-Hao; Huang, Tzu-Hsuan; Ho, Chong-Long; Wu, Meng-Chyi

    2013-03-01

    Transparent conducting oxides have been widely employed in optoelectronic devices using the various deposition methods such as sputtering, thermal evaporator, and e-gun evaporator technologies.1-3 In this work, gallium doped zinc oxide (ZnO:Ga) thin films were grown on glass substrates via H2O-thermal atomic layer deposition (ALD) at different deposition temperatures. ALD-GZO thin films were constituted as a layer-by-layer structure by stacking zinc oxides and gallium oxides. Diethylzinc (DEZ), triethylgallium (TEG) and H2O were used as zinc, gallium precursors and oxygen source, respectively. Furthermore, we investigated the influences of O2 plasma post-treatment power on the surface morphology, electrical and optical property of ZnO:Ga films. As the result of O2 plasma post-treatment, the characteristics of ZnO:Ga films exhibit a smooth surface, low resistivity, high carrier concentration, and high optical transmittance in the visible spectrum. However, the transmittance decreases with O2 plasma power in the near- and mid-infrared regions.

  6. Ultrafast electron diffraction studies of optically excited thin bismuth films

    Energy Technology Data Exchange (ETDEWEB)

    Rajkovic, Ivan

    2008-10-21

    This thesis contains work on the design and the realization of an experimental setup capable of providing sub-picosecond electron pulses for ultrafast electron diffraction experiments, and performing the study of ultrafast dynamics in bismuth after optical excitation using this setup. (orig.)

  7. Hydrophobicity enhancement of Al2O3 thin films deposited on polymeric substrates by atomic layer deposition with perfluoropropane plasma treatment

    Science.gov (United States)

    Ali, Kamran; Choi, Kyung-Hyun; Kim, Chang Young; Doh, Yang Hoi; Jo, Jeongdai

    2014-06-01

    The optoelectronics devices such as organic light emitting diodes are greatly vulnerable to moisture, which reduces their functionality and life cycle. The Al2O3 thin films are mostly used as barrier coatings in such electronic devices to protect them from water vapors. The performance of the Al2O3 barrier films can be improved by enhancing their hydrophobicity. Greater the hydrophobicity of the barrier films, greater will be their protection against water vapors. This paper reports on the enhancement of hydrophobicity of Al2O3 thin films through perfluoropropane (C3F8) plasma treatment. Firstly, good quality Al2O3 films have been fabricated through atomic layer deposition (ALD) on polyethylene naphthalate (PEN) substrates at different temperatures. The fabricated films are then plasma treated with C3F8 to enhance their hydrophobicity. Hydrophobic Al2O3 thin films have shown good morphological and optical properties. Low average arithmetic roughness (Ra) of 1.90 nm, 0.93 nm and 0.88 nm have been recorded for the C3F8 plasma treated films deposited at room temperature (RT), 50 °C and 150 °C, respectively. Optical transmittance of more than 90% has been achieved for the C3F8 plasma treated films grown at 50 °C and 150 °C. The contact angle has been increased from 48° ± 3 to 158° ± 3 for the films deposited at RT and increased from 41° ± 3 to 148° ± 3 for the films deposited at 150 °C.

  8. Optically controlled polarization in highly oriented ferroelectric thin films

    Science.gov (United States)

    Borkar, Hitesh; Tomar, M.; Gupta, Vinay; Katiyar, Ram S.; Scott, J. F.; Kumar, Ashok

    2017-08-01

    The out-of-plane and in-plane polarization of (Pb0.6Li0.2Bi0.2)(Zr0.2Ti0.8)O3 (PLBZT) thin film has been studied in the dark and under illumination from a weak light source of a comparable bandgap. A highly oriented PLBZT thin film was grown on a LaNiO3/LaAlO3 substrate by pulsed laser deposition; it showed well-saturated polarization which was significantly enhanced under light illumination. We employed two configurations for polarization characterization: the first deals with out-of-plane polarization with a single capacitor under investigation, whereas the second uses two capacitors connected in series via the bottom electrode. Two different configurations were illuminated using different energy sources and their effects were studied. The latter configuration shows a significant change in polarization under light illumination that may provide an extra degree of freedom for device miniaturization. The polarization was also tested using positive-up and negative-down measurements, confirming robust polarization and its switching under illumination.

  9. Synthesis and optical characterization of nanocrystalline CdTe thin films

    Science.gov (United States)

    Al-Ghamdi, A. A.; Khan, Shamshad A.; Nagat, A.; Abd El-Sadek, M. S.

    2010-11-01

    From several years the study of binary compounds has been intensified in order to find new materials for solar photocells. The development of thin film solar cells is an active area of research at this time. Much attention has been paid to the development of low cost, high efficiency thin film solar cells. CdTe is one of the suitable candidates for the production of thin film solar cells due to its ideal band gap, high absorption coefficient. The present work deals with thickness dependent study of CdTe thin films. Nanocrystalline CdTe bulk powder was synthesized by wet chemical route at pH≈11.2 using cadmium chloride and potassium telluride as starting materials. The product sample was characterized by transmission electron microscope, X-ray diffraction and scanning electron microscope. The structural characteristics studied by X-ray diffraction showed that the films are polycrystalline in nature. CdTe thin films with thickness 40, 60, 80 and 100 nm were prepared on glass substrates by using thermal evaporation onto glass substrate under a vacuum of 10 -6 Torr. The optical constants (absorption coefficient, optical band gap, refractive index, extinction coefficient, real and imaginary part of dielectric constant) of CdTe thin films was studied as a function of photon energy in the wavelength region 400-2000 nm. Analysis of the optical absorption data shows that the rule of direct transitions predominates. It has been found that the absorption coefficient, refractive index ( n) and extinction coefficient ( k) decreases while the values of optical band gap increase with an increase in thickness from 40 to 100 nm, which can be explained qualitatively by a thickness dependence of the grain size through decrease in grain boundary barrier height with grain size.

  10. Determination of dispersive optical constants of nanocrystalline CdSe (nc-CdSe) thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Kriti; Al-Kabbi, Alaa S.; Saini, G.S.S. [Centre of Advanced Study in Physics, Department of Physics, Panjab University, Chandigarh 160014 (India); Tripathi, S.K., E-mail: surya@pu.ac.in [Centre of Advanced Study in Physics, Department of Physics, Panjab University, Chandigarh 160014 (India)

    2012-06-15

    Highlights: ► nc-CdSe thin films are prepared by thermal vacuum evaporation technique. ► TEM analysis shows NCs are spherical in shape. ► XRD reveals the hexagonal (wurtzite) crystal structure of nc-CdSe thin films. ► The direct optical bandgap of nc-CdSe is 2.25 eV in contrast to bulk (1.7 eV). ► Dispersion of refractive index is discussed in terms of Wemple–DiDomenico single oscillator model. -- Abstract: The nanocrystalline thin films of CdSe are prepared by thermal evaporation technique at room temperature. These thin films are characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD) and photoluminescence spectroscopy (PL). The transmission spectra are recorded in the transmission range 400–3300 nm for nc-CdSe thin films. Transmittance measurements are used to calculate the refractive index (n) and absorption coefficient (α) using Swanepoel's method. The optical band gap (E{sub g}{sup opt}) has been determined from the absorption coefficient values using Tauc's procedure. The optical constants such as extinction coefficient (k), real (ε{sub 1}) and imaginary (ε{sub 2}) dielectric constants, dielectric loss (tan δ), optical conductivity (σ{sub opt}), Urbach energy (E{sub u}) and steepness parameter (σ) are also calculated for nc-CdSe thin films. The normal dispersion of refractive index is described using Wemple–DiDomenico single-oscillator model. Refractive index dispersion is further analysed to calculate lattice dielectric constant (ε{sub L}).

  11. Non-thermal atmospheric pressure plasma etching of F:SnO2 for thin film photovoltaics.

    Science.gov (United States)

    Hodgkinson, J L; Thomson, M; Cook, I; Sheel, D W

    2011-09-01

    Thin film based photovoltaic systems offer significant advantage over wafer based technologies enabling the use of low cost, large area substrates such as glass, greatly facilitating the construction and integration of large modules. The viability of such systems has advanced in recent years, with researchers striving to optimise performance through the development of materials and cell design. One way to improve efficiency is to texture the interface between the TCO and the absorber layer to maximise scattering over the appropriate wavelength range, with nanometre scale features such as pyramids being reported as giving high scatter. These textures may be achieved by advanced growth processes, such as CVD, post growth etching or a combination of both. In this work, textured F:SnO2 films produced by APCVD were favourably modified using a remote, non thermal, atmospheric plasma to activate a selective dry etch process resulting in significantly enhanced topography. Uniform treatment of the samples was achieved by translation of the samples below the plasma head. Advantages of this approach, compared to competitive technologies such as wet chemical processes, are the relatively low power consumption and ease of scalability and retroprocess integration. The modified structures were studied using AFM, SEM and EDAX, with the observed topography controlled by process variables. Optical properties were assessed along with Hall measurements.

  12. Optical absorption enhancement in a hybrid system photonic crystal - thin substrate for photovoltaic applications.

    Science.gov (United States)

    Buencuerpo, Jeronimo; Munioz-Camuniez, Luis E; Dotor, Maria L; Postigo, Pablo A

    2012-07-02

    A hybrid approach for light trapping using photonic crystal nanostructures (nanorods, nanopillars or nanoholes) on top of an ultra thin film as a substrate is presented. The combination of a nanopatterned layer with a thin substrate shows an enhanced optical absorption than equivalent films without patterning and can compete in performance with nanostructured systems without a substrate. The designs are tested in four relevant materials: amorphous silicon (a-Si), crystalline silicon (Si), gallium arsenide (GaAs) and indium phosphide (InP). A consistent enhancement is observed for all of the materials when using a thin hybrid system (300 nm) even compared to the non patterned thin film with an anti-reflective coating (ARC). A realistic solar cell structure composed of a hybrid system with a layer of indium tin oxide (ITO) an ARC and a back metal layer is performed, showing an 18% of improvement for the nanostructured device.

  13. Laser modulated scattering as a nondestructive evaluation tool for optical surfaces and thin film coatings

    Energy Technology Data Exchange (ETDEWEB)

    Feit, M D; Kozlowski, M R; Rubenchik, A M; Sheehan, L; Wu, Z L

    1999-12-22

    Laser modulated scattering (LMS) is introduced as a non-destructive evaluation tool for defect inspection and characterization of optical surfaces and thin film coatings. This technique is a scatter sensitive version of the well-known photothermal microscopy (PTM) technique. It allows simultaneous measurement of the DC and AC scattering signals of a probe laser beam from an optical surface. By comparison between the DC and AC scattering signals, one can differentiate absorptive defects from non-absorptive ones. This paper describes the principle of the LMS technique and the experimental setup, and illustrates examples on using LMS as a tool for nondestructive evaluation of high quality optics.

  14. Effect of In-doping on the Optical Constants of ZnO Thin Films

    Science.gov (United States)

    Xie, G. C.; Fanga, L.; Peng, L. P.; Liu, G. B.; Ruan, H. B.; Wu, F.; Kong, C. Y.

    Highly transparent and conductive Indium-doped ZnO (ZnO:In) thin films with different In content were deposited on quartz glass slides by RF magnetron sputtering at room temperature. The thickness and the optical constants of the films were obtained by the Swanepoel method, and the effects of In concentration on the optical constants were investigated. Calculated results show that both the refractive index and optical band gap first increase then decreases with In concentration increasing in the visible region, and the variation of both ɛr and ɛi with wavelength follows the same trend as that of refractive index and extinction coefficient, respectively.

  15. Growth,Structural and Optical Characterization of Se75Te17Ge8 Thin Films

    Institute of Scientific and Technical Information of China (English)

    SALIM; S; M; LAHMAR; A; ZAYIED; H; SALEM; A; M; SAKR; G; B; BARROY; P; TELEB; N; EL; MARSSI; M

    2015-01-01

    Se75Te17Ge8 thin film was processed on glass substrates by a pulsed laser deposition technique. The ceramic target used for the deposition was prepared by a solid state sintering method in a vacuum sealed silica tube. The structural characterization was investigated by X-ray diffraction coupled with energy-dispersive X-ray spectrometry. The optical parameters were determined from the transmittance and reflectance spectra of the prepared film. The Wemple and Di Domenico models both were appropriate to describe the experimental results. The optical absorption coefficient was analyzed to identify the type of the optical transition and determine the corresponding energy values.

  16. Growth, Structural and Optical Characterization of Se75Te17Ge8 Thin Films

    Institute of Scientific and Technical Information of China (English)

    SALIM S M; LAHMAR A; ZAYIED H; SALEM A M; SAKR G B; BARROY P; TELEB N; EL MARSSI M

    2015-01-01

    Se75Te17Ge8 thin film was processed on glass substrates by a pulsed laser deposition technique. The ceramic target used for the deposition was prepared by a solid state sintering method in a vacuum sealed silica tube. The struc-tural characterization was investigated by X-ray diffraction coupled with energy-dispersive X-ray spectrometry. The op-tical parameters were determined from the transmittance and reflectance spectra of the prepared film. The Wemple and DiDomenico models both were appropriate to describe the experimental results. The optical absorption coefficient was analyzed to identify the type of the optical transition and determine the corresponding energy values.

  17. SU-8 photolithography on reactive plasma thin-films: coated microwells for peptide display.

    Science.gov (United States)

    Marchesan, Silvia; Easton, Christopher D; Styan, Katie E; Leech, Patrick; Gengenbach, Thomas R; Forsythe, John S; Hartley, Patrick G

    2013-08-01

    We have developed a technique to create 50μm-deep microwells coated with a reactive and robust thin film, which withstands photolithographic processing, and allows for subsequent chemical functionalisation with biological cues (i.e. peptides). First, plasma polymerisation of 1-bromopropane was used to generate a bromine-functionalised thin film (BrPP) on a substrate of silicon wafer. Second, an epoxy functionalised polymer UV photoresist, SU-8, was deposited and developed to create 50μm-deep patterned microwells that display the BrPP coating at their base. Third, amino acids or peptides were selectively attached to the bottom of the microwells through bromine displacement by an amine or thiol nucleophile. Each surface functionalisation step was monitored by XPS, AFM, and contact angle measurements. These functionalities were then used as linkers to immobilise enzymes (e.g. HRP), which retain activity at the end of the process as shown by a biochemical activity assay. Peptide promoters of cell attachment were also immobilised and their functionality was evaluated using an L929 fibroblast adhesion assay. In conclusion, this work describes an innovative combination of plasma thin film deposition and photolithography to create 50μm-deep functionalised microwells for peptide display in biological applications.

  18. Luminescent Nanocrystalline Silicon Carbide Thin Film Deposited by Helicon Wave Plasma Enhanced Chemical Vapour Deposition

    Institute of Scientific and Technical Information of China (English)

    LU Wan-bing; YU Wei; WU Li-ping; CUI Shuang-kui; FU Guang-sheng

    2006-01-01

    Hydrogenated nanocrystalline silicon carbide (SiC) thin films were deposited on the single-crystal silicon substrate using the helicon wave plasma enhanced chemical vapor deposition (HW-PECVD) technique. The influences of magnetic field and hydrogen dilution ratio on the structures of SiC thin film were investigated with the atomic force microscopy (AFM), the Fourier transform infrared absorption (FTIR) and the transmission electron microscopy (TEM). The results indicate that the high plasma activity of the helicon wave mode proves to be a key factor to grow crystalline SiC thin films at a relative low substrate temperature. Also, the decrease in the grain sizes from the level of microcrystalline to that of nanocrystalline can be achieved by increasing the hydrogen dilution ratios. Transmission electron microscopy measurements reveal that the size of most nanocrystals in the film deposited under the higher hydrogen dilution ratios is smaller than the doubled Bohr radius of 3C-SiC (approximately 5.4 nm), and the light emission measurements also show a strong blue photoluminescence at the room temperature, which is considered to be caused by the quantum confinement effect of small-sized SiC nanocrystals.

  19. Adhesion improvement of hydrogenated diamond-like carbon thin films by pre-deposition plasma treatment of rubber substrate

    NARCIS (Netherlands)

    Bui, X.L.; Pei, Y.T.; Mulder, E.D.G.; Hosson, J.Th.M. De

    2009-01-01

    For reduction of friction and enhancement of wear resistance of dynamic rubber seals, thin films of hydrogenated diamond-like carbon (DLC) have been deposited on hydrogenated nitrile butadiene rubber (HNBR) via magnetron-enhanced plasma chemical vapor deposition (ME-PCVD). Pre-deposition plasma trea

  20. Optical and electrical properties of boron doped diamond thin conductive films deposited on fused silica glass substrates

    Energy Technology Data Exchange (ETDEWEB)

    Ficek, M.; Sobaszek, M.; Gnyba, M. [Department of Metrology and Optoelectronics, Gdansk University of Technology, 11/12G. Narutowicza St., 80-233 Gdansk (Poland); Ryl, J. [Department of Electrochemistry, Corrosion and Material Engineering, Gdansk University of Technology, 11/12 Narutowicza St., 80-233 Gdansk (Poland); Gołuński, Ł. [Department of Metrology and Optoelectronics, Gdansk University of Technology, 11/12G. Narutowicza St., 80-233 Gdansk (Poland); Smietana, M.; Jasiński, J. [Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, 75 Koszykowa St., 00-662 Warsaw (Poland); Caban, P. [Institute of Electronic Materials Technology, 133 Wolczynska St., 01-919 Warsaw (Poland); Bogdanowicz, R., E-mail: rbogdan@eti.pg.gda.pl [Department of Metrology and Optoelectronics, Gdansk University of Technology, 11/12G. Narutowicza St., 80-233 Gdansk (Poland); Materials and Process Simulation Center, California Institute of Technology, Pasadena, CA 91125 (United States)

    2016-11-30

    Highlights: • Growth of 60% of transmittance diamond films with resistivity as low as 48 Ω cm. • Two step seeding process of fused silica: plasma hydrogenation and wet seeding. • Nanodiamond seeding density of 2 × 10{sup 10} cm{sup −2} at fused silica substrates. • High refractive index (2.4 @550 nm) was achieved for BDD films deposited at 500 °C. - Abstract: This paper presents boron-doped diamond (BDD) film as a conductive coating for optical and electronic purposes. Seeding and growth processes of thin diamond films on fused silica have been investigated. Growth processes of thin diamond films on fused silica were investigated at various boron doping level and methane admixture. Two step pre-treatment procedure of fused silica substrate was applied to achieve high seeding density. First, the substrates undergo the hydrogen plasma treatment then spin-coating seeding using a dispersion consisting of detonation nanodiamond in dimethyl sulfoxide with polyvinyl alcohol was applied. Such an approach results in seeding density of 2 × 10{sup 10} cm{sup −2}. The scanning electron microscopy images showed homogenous, continuous and polycrystalline surface morphology with minimal grain size of 200 nm for highly boron doped films. The sp{sup 3}/sp{sup 2} ratio was calculated using Raman spectra deconvolution method. A high refractive index (range of 2.0–2.4 @550 nm) was achieved for BDD films deposited at 500 °C. The values of extinction coefficient were below 0.1 at λ = 550 nm, indicating low absorption of the film. The fabricated BDD thin films displayed resistivity below 48 Ohm cm and transmittance over 60% in the visible wavelength range.

  1. The effect of substrate temperature on the optical properties of polycrystalline Sb 2O 3 thin films

    Science.gov (United States)

    Tigau, N.; Ciupina, V.; Prodan, G.

    2005-04-01

    Polycrystalline antimony trioxide (Sb 2O 3) thin films with a thickness of 800 nm, deposited on glass substrates at different temperature ranges 300-573 K, were optically characterized. The optical parameters such as refractive index, n, absorption coefficient, α, and optical band gap, Eg, were determined using the transmission spectra recorded in the range of 300-1400 nm and simple calculations based on Swanepoel's method including interference effect induced by multiple internal reflections in the substrate/thin film system. The effect of substrate temperature on the optical properties of Sb 2O 3 thin films has been studied. It was found that both refractive index and absorption coefficient depend markedly on the substrate temperature. The optical band gap energies and the corresponding allowed direct transitions have been determined from the absorption spectra. The correlations between optical parameters and the change in structure of the Sb 2O 3 thin films are discussed.

  2. Effect of thermal annealing on structural and optical properties of In2S3 thin films

    Science.gov (United States)

    Choudhary, Sonu

    2015-08-01

    There is a highly need of an alternate of toxic materials CdS for solar cell applications and indium sulfide is found the most suitable candidate to replace CdS due to its non-toxic and environmental friendly nature. In this paper, the effect of thermal annealing on the structural and optical properties of indium sulfide (In2S3) thin films is undertaken. The indium sulfide thin films of 121 nm were deposited on glass substrates employing thermal evaporation method. The films were subjected to the X-ray diffractometer and UV-Vis spectrophotometer respectively for structural and optical analysis. The XRD pattern show that the as-deposited thin film was amorphous in nature and crystallinity is found to be varied with annealing temperature. The optical analysis reveals that the optical band gap is varied with annealing. The optical parameters like absorption coefficient, extinction coefficient and refractive index were calculated. The results are in good agreement with available literature.

  3. Optical behavior of silver nanoparticles embedded in polymer thin film layers

    Science.gov (United States)

    Carlberg, M.; Pourcin, F.; Margeat, O.; Le Rouzo, J.; Berginc, G.; Sauvage, R.-M.; Ackermann, J.; Escoubas, L.

    2016-09-01

    The study of metal nanoparticles (NPs) is challenging for the control of the light matter interaction phenomena. In this context, our work is focused on optical characterization and modeling of polymer thin films layers with inclusions of previously chemically synthesized NPs. Through the presence of metallic NPs in polymer thin films, the optical properties are assumed to become tunable. Thin film layers with inclusions of differently shaped and sized silver NPs, such as nanospheres and nanoprisms, are optically characterized to get the scattering, the reflection and the absorption of the layers. One step and two step seed based methods of silver ions reduction are used for the chemical synthesis of nanospheres and nanoprisms. The plasmonic resonance peaks of these colloidal solutions range from 360 to 1300 nm. A poly vinyl pyrrolidone (PVP) polymer matrix is chosen for its light non-absorbing and NP-stabilizing properties. Knowledge on the shape and size of the NPs embedded in the spin coated layers is obtained by transmission electron microscopy (TEM) imaging. The optical properties include spectrophotometry and spectroscopic ellipsometry (SE) measurements to get the reflectance, the transmittance, the absorptance and the optical indices n and k of the heterogeneous layers. A redshift in absorption is measured between deposited nanospheres and other shaped NPs. FDTD simulations allow calculation of far and near field properties. The visualization of the NP interactions and the electric field enhancement, on and around the NPs, are studied to improve the understanding of the far field properties.

  4. Structural, Optical, and Dielectric Properties of Azure B Thin Films and Impact of Thermal Annealing

    Science.gov (United States)

    Zeyada, H. M.; Zidan, H. M.; Abdelghany, A. M.; Abbas, I.

    2017-03-01

    Thin films of azure B (AB) have been prepared by thermal evaporation. Structural, optical, and dielectric characteristics of as-prepared and annealed samples were studied. AB is polycrystalline in as-synthesized powder form. Detailed x-ray diffraction studies showed amorphous structure for pristine and annealed films. Fourier-transform infrared vibrational spectroscopy indicated minor changes in molecular bonds of AB thin films either after deposition or after thermal annealing. Optical transmittance and reflection spectra of prepared thin films were studied at nearly normal light incidence in the spectral range from 200 nm to 2500 nm, showing marked changes without new peaks. Annealing increased the absorption coefficient and decreased the optical bandgap. Onset and optical energy gaps of pristine films were found to obey indirect allowed transition with values of 1.10 eV and 2.64 eV, respectively. Annealing decreased the onset and optical energy gaps to 1.0 eV and 2.57 eV, respectively. The dispersion parameters before and after annealing are discussed in terms of a single-oscillator model. The spectra of the dielectric constants (ɛ 1, ɛ 2) were found to depend on the annealing temperature in addition to the incident photon energy.

  5. Ion Beam Assisted Deposition Of Optical Thin Films - Recent Results

    Science.gov (United States)

    McNally, J. J.; Al-Jumaily, G. A.; Wilson, S. R.; McNeil, J. R.

    1985-11-01

    We have examined the properties of dielectric (Ti02, Si02, -Al203, Ta205 and Hf02) films deposited using ion-assisted deposition (IAD). The films were characterized using an angularly resolved scatterometer, spectrophotometer and Raman spectroscopy. A reduction in optical scatter, especially that due to low spatial frequencies, is observed for films deposited with simultaneous ion bombardment. Higher values of refractive index are obtained for films deposited using IAD. Raman spectra indicate a crystalline phase change in TiO2 films is induced by bombardment of samples with 02 ions during deposition. Other experimental data and the effects of the induced phase transition on the optical properties of TiO2 will be discussed.

  6. Optical Thin Film Modeling: Using FTG's FilmStar Software

    Science.gov (United States)

    Freese, Scott

    2009-01-01

    Every material has basic optical properties that define its interaction with light: The index of refraction (n) and extinction coefficient (k) vary for the material as a function of the wavelength of the incident light. Also significant are the phase velocity and polarization of the incident light These inherent properties allow for the accurate modeling of light s behavior upon contact with a surface: Reflectance, Transmittance, Absorptance.

  7. Dielectric and optical properties of sputtered thin films

    Science.gov (United States)

    Tanguay, A. R., Jr.

    1984-07-01

    Of critical importance to the eventual performance of numerous coherent optical image processors and highly parallel computers is the development of a high speed, recyclable, linear, high resolution, selectively erasable image storage transducer operable in nearly real time. Applications for such a transducer abound, including incoherent-to-coherent conversion, pattern recognition and image feature extraction, level slicing, edge enhancement, low light level image integration, scratch pad memory, and page composition for data entry in holographic memory systems. In response to this need, a wide variety of candidate devices have been proposed in the past ten years, based on photochromic, liquid crystal, photorefractive, magnetooptic, electrooptic, deformable membrane, thermoplastic, photodichroic, and ambidextrous effects in numerous configurations. The device category comprised of Electrooptic Spatial Light Modulators contains a number of leading candidates, due to a combination of wide dynamic range, high sensitivity, intermediate storage time, relative simplicity of construction and operation, and long term durability. This category includes the Pockels Readout Optical Modulator or PROM, a Soviet modification of th PROM called the PRIZ, the Microchannel Spatial Light Modulator, the TITUS and photo-TITUS, and the Photorefractive Incoherent-to-Coherent Optical Converter.

  8. Optical layer development for thin films thermal conductivity measurement by pulsed photothermal radiometry

    Energy Technology Data Exchange (ETDEWEB)

    Martan, J., E-mail: jmartan@ntc.zcu.cz [New Technologies Research Centre, University of West Bohemia, Univerzitní 8, 306 14 Plzeň (Czech Republic)

    2015-01-15

    Measurement of thermal conductivity and volumetric specific heat of optically transparent thin films presents a challenge for optical-based measurement methods like pulsed photothermal radiometry. We present two approaches: (i) addition of an opaque optical layer to the surface and (ii) approximate correction of the mathematical model to incorporate semitransparency of the film. Different single layer and multilayer additive optical layers were tested. The materials of the optical layers were chosen according to analysis and measurement of their optical properties: emissivity and absorption coefficient. Presented are thermal properties’ measurement results for 6 different thin films with wide range of thermal conductivity in three configurations of surface: as deposited, added Ti layer, and added Ti/TiAlSiN layer. Measurements were done in dependence on temperature from room temperature to 500 °C. The obtained thermal effusivity evolution in time after the laser pulse shows different effects of the surface layers: apparent effusivity change and time delay. Suitability of different measurement configurations is discussed and results of high temperature testing of different optical layers are presented.

  9. Optical characterization of a-Se85−Te15Zn thin films

    Indian Academy of Sciences (India)

    S Shukla; S Kumar

    2012-02-01

    Thin films of Se85−Te15Zn ( = 0, 2, 4, 6 and 10) glassy alloys have been deposited onto a chemically cleaned glass substrate by thermal evaporation technique under vacuum. The analysis of transmission spectra, measured at normal incidence, in the spectral range of 400–2500 nm helped us in the optical characterization of thin films under study. From the analysis of transmission spectra, the optical parameters such as refractive index (), extinction coefficient (), absorption coefficient (), real and imaginary dielectric constants (' and ") have been calculated. It is observed that the parameters , , ', " and decrease with increase in wavelength () and increase with Zn content. Optical band gap ($E_g$) has also been calculated and found to decrease with Zn content in Se85−Te15Zn glassy system which could be correlated with increase in the density of defect states.

  10. Structural, Optical, and Electrical Characterization of Spray Pyrolysed Indium Sulfide Thin Films

    Science.gov (United States)

    Rahman, F.; Podder, J.; Ichimura, M.

    2013-03-01

    Indium sulfide (In2S3) thin films were deposited onto the glass substrates by a low cost simple spray pyrolysis technique at 300°C temperature. Aqueous solution of indium chloride and thiourea were used to deposit the binary In-S film. The deposited thin films were annealed at 400° and 500°C temperatures and characterized structurally, optically and electrically using EDX, X-ray diffraction, UV-visible spectroscopy and four probe van der Pauw methods. The optical constants such as refractive index and extinction coefficient are calculated from absorbance and transmittance data from 300 to 1100 nm wavelength. The optical transmittance increased after annealing at 400° and 500°C. The band gap energy was reduced from 2.90 to 2.50 eV after annealing the as deposited films. The electrical conductivity as well as the activation energy was increased after annealing the samples.

  11. Thermal annealing induced structural and optical properties of Se72Te25In3 thin films

    Science.gov (United States)

    Pathak, H. P.; Shukla, Nitesh; Kumar, Vipin; Dwivedi, D. K.

    2016-05-01

    Thin films of a- Se72Te25In3 were prepared by vacuum evaporation technique in a base pressure of 10-6 Torr on to well cleaned glass substrate. a-Se72Te25In3 thin films were annealed at different temperatures below their crystallization temperatures for 2h. The structural analysis of the films has been investigated using X-ray diffraction technique. The optical absorption spectra of these films were measured in the wavelength range 400-1100 nm in order to derive the absorption coefficient of these films. The optical band gap of as prepared and annealed films as a function of photon energy has been studied. It has been found that the optical band gap decreases with increasing annealing temperatures in the present system.

  12. The rapid and precise determination of the optical thickness of thin coatings in a vacuum.

    Science.gov (United States)

    van Heel, A C; van Vonno, W

    1967-05-01

    The classical interference experiment with a double slit is adapted for measuring the optical thickness (n - 1)d of transparent and slightly absorbing thin films on transparent or reflecting substrates and for measuring the geometrical thickness d of metal films on reflecting substrates. Also, a method is described for measuring in vacuum the optical thickness of transparent or slightly absorbing thin films on transparent substrates. Results are given of measurements on magnesium fluoride, silicon monoxide, and zinc sulfide films. The influence of admitting air into the vacuum chamber has been investigated. With the available arrangements, a precision of lambda/1000 in the determination of the optical or geometrical thickness is easily obtainable for all film thicknesses. A thickness determination can he completed in about 1 min.

  13. Temperature influence on microstructure and optical properties of TiO2-Au thin films

    Science.gov (United States)

    Lahmar, A.; Benchaabane, A.; Aderdour, M.; Zeinert, A.; Es-Souni, M.

    2016-02-01

    TiO2-Au thin films were deposited on quartz substrate using sol-gel technique. The influence of the annealing temperature on microstructure and optical properties was examined. SEM micrographs showed a homogeneous distribution of Au nanoparticles when the annealing temperature is increased. X-ray diffraction and Raman spectroscopy allowed the identification of the anatase phase at 500 °C that persisted up to 800 °C. Optical spectra showed the presence of localized plasmon resonance as a result of the presence of Au nanoparticles; the loci of the absorption peaks were found to depend on the annealing temperature. The effective medium model was used to describe the spectrophotometric measurements. Numerical calculations permitted the determination of optical constants. The band gap E g of TiO2-Au thin films was found to decrease from 3.21 to 2.71 eV with increasing annealing temperature.

  14. Optical properties of amorphous and polycrystalline Sb2Se3 thin films prepared by thermal evaporation

    Science.gov (United States)

    Chen, Chao; Li, Weiqi; Zhou, Ying; Chen, Cheng; Luo, Miao; Liu, Xinsheng; Zeng, Kai; Yang, Bo; Zhang, Chuanwei; Han, Junbo; Tang, Jiang

    2015-07-01

    Sb2Se3 is a very promising photovoltaic material because of its attractive material, optical and electrical properties. Very recently, we reported a superstrate CdS/Sb2Se3 solar cell with 5.6% certified efficiency. In this letter, we focused on the optical properties of amorphous and polycrystalline Sb2Se3 thin films prepared by thermal evaporation. Using temperature dependent transmission spectrum and temperature dependent photoluminescence, the indirect optical transition nature and bandgap values as functions of temperature were acquired. Using ellipsometry measurements and Swanepoel's envelope method, the refractive indices as well as the dielectric constant in a wide wavelength range of 193-2615 nm were obtained. These works would lay the foundation for the further development of Sb2Se3 thin film solar cells.

  15. Effect of Annealing on Structural and Optical Properties of Cu Doped In2O3 Thin Films

    OpenAIRE

    S. Kaleemulla; N. Madhusudhana Rao; N. Sai Krishna; M. Kuppan; M. Rigana Begam; M. Shobana

    2014-01-01

    Cu-doped In2O3 thin films were prepared using flash evaporation method at different Cu-doping levels. The effect of annealing was studied on the structure, morphology and optical properties of the thin films. The films exhibited cubic structure and optical transmittance of the films increasing with annealing temperature. The highest optical transmittance of 78 % was observed with band gap of 4.09 eV.

  16. Electrochemical Evaluation of Thin-Film Li-Si Anodes Prepared by Plasma Spraying

    Energy Technology Data Exchange (ETDEWEB)

    GUIDOTTI,RONALD A.; REINHARDT,FREDERICK W.; SCHARRER,GREGORY L.

    1999-09-08

    Thin-film electrodes of a plasma-sprayed Li-Si alloy were evaluated for use as anodes in high-temperature thermally activated (thermal) batteries. These anodes were prepared using 44% Li/56% Si (w/w) material as feed material in a special plasma-spray apparatus under helium or hydrogen, to protect this air- and moisture-sensitive material during deposition. Anodes were tested in single cells using conventional pressed-powder separators and lithiated pyrite cathodes at temperatures of 400 to 550 C at several different current densities. A limited number of 5-cell battery tests were also conducted. The data for the plasma-sprayed anodes was compared to that for conventional pressed-powder anodes. The performance of the plasma-sprayed anodes was inferior to that of conventional pressed-powder anodes, in that the cell emfs were lower (due to the lack of formation of the desired alloy phases) and the small porosity of these materials severely limited their rate capability. Consequently, plasma-sprayed Li-Si anodes would not be practical for use in thermal batteries.

  17. Structural and optical properties of chlorinated plasma polymers

    Energy Technology Data Exchange (ETDEWEB)

    Turri, Rafael [Laboratorio de Plasmas Tecnologicos, Campus Experimental de Sorocaba, Universidade Estadual Paulista (UNESP), Avenida Tres de Marco 511, Alto de Boa Vista, 18087-180, Sorocaba, SP (Brazil); Davanzo, Celso U. [Instituto de Quimica, Universidade Estadual de Campinas, Campinas, SP (Brazil); Schreiner, Wido [Departamento de Fisica, Universidade Federal de Parana, PR (Brazil); Dias da Silva, Jose Humberto [Faculdade de Ciencias, Universidade Estadual Paulista (UNESP), Bauru, SP (Brazil); Appolinario, Marcelo Borgatto [Laboratorio de Plasmas Tecnologicos, Campus Experimental de Sorocaba, Universidade Estadual Paulista (UNESP), Avenida Tres de Marco 511, Alto de Boa Vista, 18087-180, Sorocaba, SP (Brazil); Durrant, Steven F., E-mail: steve@sorocaba.unesp.br [Laboratorio de Plasmas Tecnologicos, Campus Experimental de Sorocaba, Universidade Estadual Paulista (UNESP), Avenida Tres de Marco 511, Alto de Boa Vista, 18087-180, Sorocaba, SP (Brazil)

    2011-12-30

    Amorphous hydrogenated chlorinated carbon (a-C:H:Cl) films were produced by the plasma polymerization of chloroform-acetylene-argon mixtures in a radiofrequency plasma enhanced chemical vapor deposition system. The main parameter of interest was the proportion of chloroform in the feed, R{sub C}, which was varied from 0 to 80%. Deposition rates of 80 nm min{sup -1} were typical for the chlorinated films. Infrared reflection-absorption spectroscopy revealed the presence of C-Cl groups in all the films produced with chloroform in the feed. X-ray photoelectron spectroscopy confirmed this finding, and revealed a saturation of the chlorine content at {approx} 47 at.% for R{sub C} {>=} 40%. The refractive index and optical gap, E{sub 04}, of the films were roughly in the 1.6 to 1.7, and the 2.8 to 3.7 eV range. These values were calculated from transmission ultraviolet-visible-near infrared spectra. Chlorination leads to an increase in the water surface contact angle from {approx} 40 Degree-Sign to {approx} 77 Degree-Sign .

  18. Optical Emission Spectroscopic Studies of ICP Ar Plasma

    Institute of Scientific and Technical Information of China (English)

    QI Xuelian; REN Chunsheng; ZHANG Jian; MA Tengcai

    2007-01-01

    The ion line of 434.8 nm and atom line of 419.8 nm of Ar plasma produced by an inductively coupled plasma (ICP) were measured by optical emission spectroscopy and the influences from the working gas pressure, radio-frequency (RF) power and different positions in the discharge chamber on the line intensities were investigated in this study. It was found that the intensity of Ar atom line increased firstly and then saturated with the increase of the pressure. The line intensity of Ar+, on the other hand, reached a maximum value and then decreased along with the pressure. The intensity of the line in an RF discharge also demonstrated a jumping mode and a hysteresis phenomenon with the RF power. When the RF power increased to 400 W, the discharge jumped from the E-mode to the H-mode where the line intensity of Ar atom demonstrated a sudden increase, while the intensity of Ar+ ion only changed slightly. If the RF power decreased from a high value, e.g., 1000 W, the discharge would jump from the H-mode back to the E-mode at a power of 300 W. At this time the intensities of Ar and Ar+ lines would also decrease sharply. It was also noticed in this paper that the intensity of the ion line depended on the detective location in the chamber, namely at the bottom of the chamber the line was more intense than that in the middle of the chamber, but less intense than at the top, which is considered to be related to the capacitance coupling ability of the ICP plasma in different discharge areas.

  19. Second harmonic generation in thin optical fibers via cladding modes.

    Science.gov (United States)

    Elzahaby, Eman A; Kandas, Ishac; Aly, Moustafa H

    2016-05-30

    Since silica goes under the category of amorphous materials, it is difficult to investigate important processes such as second harmonic generation (SHG) in silica-based fibers. In this paper, we proposed a method for SHG relaying on cladding modes as pump modes. Cladding modes are introduced in optical fibers through tilted long period grating (T-LPG), where power of core mode is transferred into cladding modes. By functionalizing T-LPG with nonlinear coating, the interaction occurs between cladding modes and the coating material, consequently second harmonic signal (SHS) is generated with efficiency up to 0.14%.

  20. Structural and optical properties of ZnS thin film grown by pulsed electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Hennayaka, H.M.M.N.; Lee, Ho Seong, E-mail: hs.lee@knu.ac.kr

    2013-12-02

    ZnS thin films were grown on indium–tin-oxide coated glass substrates using pulsed electrodeposition and the effect of the deposition temperature on the structural and optical properties of the ZnS films was investigated. Polycrystalline cubic ZnS films were obtained at all the deposition temperatures. At temperatures below 70 °C, less dense films were obtained and particle agglomeration was visible. On the other hand, at temperatures above 70 °C, more dense films with well-defined grains were obtained. With increasing deposition temperatures, the optical transmittance and bandgap of the ZnS films decreased. These results are attributed to the increase in the thickness of ZnS films and their particle size. The ZnS films grown at 90 °C exhibited the highly (200) preferred orientation and n-type conductivity with a wide bandgap of 3.75 eV. - Highlights: • This study describes the effect of the deposition temperature on the growth of the ZnS thin films. • ZnS thin films were grown using pulsed electrodeposition. • ZnS thin films exhibited the good crystal quality and chemical composition. • ZnS thin films exhibited n-type conductivity with a wide bandgap of 3.75 eV.

  1. Optical bandgap modeling of thermal annealed ZnO:Ga thin films using neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chang Eun; Moon, Pyung; Yun, Ilgu [School of Electrical and Electronic Engineering, Yonsei University, 262 Seongsanno, Seodaemoon-gu, Seoul 120-749 (Korea); Kim, Sungyeon; Myoung, Jae-Min [Department of Materials Science and Engineering, Yonsei University, 262 Seongsanno, Seodaemoon-gu, Seoul 120-749 (Korea); Jang, Hyeon Woo; Bang, Jungsik [LG Chem, Ltd., Research Park, 104-1 Moonji-Dong, Yuseng-Gu, Daejeon 305-380 (Korea)

    2010-07-15

    In this paper, the thermal annealing process modeling for the optical bandgap of ZnO:Ga thin films for transparent conductive oxide was presented using neural network (NNets) based on error backpropagation (BPNN) algorithm and multilayer perceptron (MLP). The thermal annealing process of ZnO:Ga thin films were analyzed by general factorial experimental design. The annealing temperature and film thickness were considered as input factors. To model the nonlinear annealing process, 6 experiments were trained by BPNN which has 2-4-1 structures and 2 additional samples were experimented to verify the predicted models. The output response model on optical bandgap and carrier concentration of ZnO:Ga thin films trained by BPNN was represented by surface plot of response surface model. Based on the modeling results, NNets can provide sufficient correspondence between the predicted output values and the measured. The optical bandgap variation of ZnO:Ga thin films by annealing is due to increased carrier concentration and explained by Burstein-Moss effect. The thermal annealing process is nonlinear and complex but the output response can be predicted by the NNets model. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  2. Deposition of electrochromic tungsten oxide thin films by plasma-enhanced chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Henley, W.B.; Sacks, G.J. [Univ. of South Florida, Tampa, FL (United States). Center of Microelectronics

    1997-03-01

    Use of plasma-enhanced chemical vapor deposition (PECVD) for electrochromic WO{sub 3} film deposition is investigated. Oxygen, hydrogen, and tungsten hexafluoride were used as source gases. Reactant gas flow was investigated to determine the effect on film characteristics. High quality optical films were obtained at deposition rates on the order of 100 {angstrom}/s. Higher deposition rates were attainable but film quality and optical coherence degraded. Atomic emission spectroscopy (AES), was used to provide an in situ assessment of the plasma deposition chemistry. Through AES, it is shown that the hydrogen gas flow is essential to the deposition of the WO{sub 3} film. Oxygen gas flow and tungsten hexafluoride gas flow must be approximately equal for high quality films.

  3. Sputter deposition of PZT piezoelectric films on thin glass substrates for adjustable x-ray optics.

    Science.gov (United States)

    Wilke, Rudeger H T; Johnson-Wilke, Raegan L; Cotroneo, Vincenzo; Davis, William N; Reid, Paul B; Schwartz, Daniel A; Trolier-McKinstry, Susan

    2013-05-10

    Piezoelectric PbZr(0.52)Ti(0.48)O(3) (PZT) thin films deposited on thin glass substrates have been proposed for adjustable optics in future x-ray telescopes. The light weight of these x-ray optics enables large collecting areas, while the capability to correct mirror figure errors with the PZT thin film will allow much higher imaging resolution than possible with conventional lightweight optics. However, the low strain temperature and flexible nature of the thin glass complicate the use of chemical-solution deposition due to warping of the substrate at typical crystallization temperatures for the PZT. RF magnetron sputtering enabled preparation of PZT films with thicknesses up to 3 μm on Schott D263 glass substrates with much less deformation. X-ray diffraction analysis indicated that the films crystallized with the perovskite phase and showed no indication of secondary phases. Films with 1 cm(2) electrodes exhibited relative permittivity values near 1100 and loss tangents below 0.05. In addition, the remanent polarization was 26 μC/cm(2) with coercive fields of 33 kV/cm. The transverse piezoelectric coefficient was as high as -6.1±0.6 C/m(2). To assess influence functions for the x-ray optics application, the piezoelectrically induced deflection of individual cells was measured and compared with finite-element-analysis calculations. The good agreement between the results suggests that actuation of PZT thin films can control mirror figure errors to a precision of about 5 nm, allowing sub-arcsecond imaging.

  4. A comparative study of the physical properties of Sb{sub 2}S{sub 3} thin films treated with N{sub 2} AC plasma and thermal annealing in N{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Calixto-Rodriguez, M., E-mail: manuela@fis.unam.mx [Instituto de Ciencias Fisicas, Universidad Nacional Autonoma de Mexico, Apartado Postal 48-3, 62210, Cuernavaca, Morelos (Mexico); Martinez, H. [Instituto de Ciencias Fisicas, Universidad Nacional Autonoma de Mexico, Apartado Postal 48-3, 62210, Cuernavaca, Morelos (Mexico); Pena, Y. [Facultad de Ciencias Quimicas, Universidad Autonoma de Nuevo Leon, Pedro de Alba s/n, Cd. Universitaria, 66451, San Nicolas de los Garza, Nuevo Leon (Mexico); Flores, O. [Instituto de Ciencias Fisicas, Universidad Nacional Autonoma de Mexico, Apartado Postal 48-3, 62210, Cuernavaca, Morelos (Mexico); Esparza-Ponce, H.E. [Centro de Investigacion en Materiales Avanzados S.C., Laboratorio Nacional de Nanotecnologia, Miguel de Cervantes 120, Complejo Industrial Chihuahua, Chihuahua, Chihuahua 31109 (Mexico); Sanchez-Juarez, A.; Campos-Alvarez, J. [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico, Privada Xochicalco s/n, Col. Centro, 62580, Temixco, Morelos (Mexico); Reyes, P. [Facultad de Ciencias, Departamento de Fisica, Universidad Autonoma del Estado de Mexico, Instituto Literario 100, Col. Centro, 50000, Toluca, Estado de Mexico (Mexico)

    2010-02-01

    As-deposited antimony sulfide thin films prepared by chemical bath deposition were treated with nitrogen AC plasma and thermal annealing in nitrogen atmosphere. The as-deposited, plasma treated, and thermally annealed antimony sulfide thin films have been characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy, scanning electron microscopy, atomic force microscopy, UV-vis spectroscopy, and electrical measurements. The results have shown that post-deposition treatments modify the crystalline structure, the morphology, and the optoelectronic properties of Sb{sub 2}S{sub 3} thin films. X-ray diffraction studies showed that the crystallinity of the films was improved in both cases. Atomic force microscopy studies showed that the change in the film morphology depends on the post-deposition treatment used. Optical emission spectroscopy (OES) analysis revealed the plasma etching on the surface of the film, this fact was corroborated by the energy dispersive X-ray spectroscopy analysis. The optical band gap of the films (E{sub g}) decreased after post-deposition treatments (from 2.36 to 1.75 eV) due to the improvement in the grain sizes. The electrical resistivity of the Sb{sub 2}S{sub 3} thin films decreased from 10{sup 8} to 10{sup 6} {Omega}-cm after plasma treatments.

  5. Properties of nanostructured undoped ZrO{sub 2} thin film electrolytes by plasma enhanced atomic layer deposition for thin film solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Gu Young; Noh, Seungtak; Lee, Yoon Ho; Cha, Suk Won, E-mail: ybkim@hanyang.ac.kr, E-mail: swcha@snu.ac.kr [Department of Mechanical and Aerospace Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Ji, Sanghoon [Graduate School of Convergence Science and Technology, Seoul National University, Iui-dong, Yeongtong-gu, Suwon 443-270 (Korea, Republic of); Hong, Soon Wook; Koo, Bongjun; Kim, Young-Beom, E-mail: ybkim@hanyang.ac.kr, E-mail: swcha@snu.ac.kr [Department of Mechanical Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 133-791 (Korea, Republic of); An, Jihwan [Manufacturing Systems and Design Engineering Programme, Seoul National University of Science and Technology, 232 Gongneung-ro, Nowon-gu, Seoul 139-743 (Korea, Republic of)

    2016-01-15

    Nanostructured ZrO{sub 2} thin films were prepared by thermal atomic layer deposition (ALD) and by plasma-enhanced atomic layer deposition (PEALD). The effects of the deposition conditions of temperature, reactant, plasma power, and duration upon the physical and chemical properties of ZrO{sub 2} films were investigated. The ZrO{sub 2} films by PEALD were polycrystalline and had low contamination, rough surfaces, and relatively large grains. Increasing the plasma power and duration led to a clear polycrystalline structure with relatively large grains due to the additional energy imparted by the plasma. After characterization, the films were incorporated as electrolytes in thin film solid oxide fuel cells, and the performance was measured at 500 °C. Despite similar structure and cathode morphology of the cells studied, the thin film solid oxide fuel cell with the ZrO{sub 2} thin film electrolyte by the thermal ALD at 250 °C exhibited the highest power density (38 mW/cm{sup 2}) because of the lowest average grain size at cathode/electrolyte interface.

  6. Elasto-Optical Properties of Thin Polymer Films by Prism Coupling Technique

    Science.gov (United States)

    Ay, Feridun; Agan, Sedat; Kocabas, Askin; Aydinli, Atilla

    2004-05-01

    Reliable measurement of stress dependent refractive index of thin polymer films has been achieved. The effect of the applied stress on the refractive index and birefringence of the films was investigated. The out-of-plane elastic moduli of the thin polymer films were deduced by using the same prism coupling setup. Three dimensional finite element method (FEM) analysis was used to obtain the principal stresses for each polymer film and combining them with the stress dependent refractive index measurements, the elasto-optic coefficients of the polymer films were determined, for the first time.

  7. Effect of air annealing on the optical electrical and structural properties of carbazole thin films

    Energy Technology Data Exchange (ETDEWEB)

    Pisharady, Sreejith K. [School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam, Kerala 656560 (India)]. E-mail: skpishar@yahoo.co.in; Menon, C.S. [School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam, Kerala 656560 (India); Sudarshana Kumar, C. [School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam, Kerala 656560 (India); Gopinathan, T.G. [School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam, Kerala 656560 (India)

    2006-11-10

    Thin films of carbazole films have been prepared using vacuum sublimation technique. Post-evaporation annealing is done for various periods of time. The optical absorption spectrum is recorded and the band gap is calculated from the observed spectrum. The current-voltage characteristics are studied for the sandwiched structure of carbazole thin films with silver electrodes. From the J-V characteristics trap density and number of thermally generated charge carriers are determined. Their structure and grain size have been determined from the X-ray diffraction studies.

  8. Optical and Electrochromic Properties of E-Beam Evaporated Nickel Oxide Thin Film

    Directory of Open Access Journals (Sweden)

    K.J. Patel

    2011-01-01

    Full Text Available Nickel oxide (NiO thin films were deposited by e-beam evaporation on glass and ITO coated glass substrates initially held at room temperature without post-heat treatments. The structural and optical properties were investigated using glancing incident X-ray diffractometer (GIXRD and spectrophotometer. The electrochromic (EC behavior of NiO thin film was investigated using electrochemical technique viz. cyclic voltammetry, constant current measurement, and chronoamperometry in 1 M KOH electrolyte. The transmittance modulation and switching time with different operating voltage were also studied.

  9. Structural, optical and electronic properties of Fe doped ZnO thin films

    Science.gov (United States)

    Singh, Karmvir; Devi, Vanita; Dhar, Rakesh; Mohan, Devendra

    2015-09-01

    Fe doped ZnO thin films have been deposited by pulsed laser deposition technique on quartz substrate to study structural, optical and electronic structure using XRD, AFM, UV-visible and X-ray absorption spectroscopy. XRD study reveals that Fe doping has considerable effect on stress, strain, grain size and crystallinity of thin films. UV-visible study determines that band gap of pristine ZnO decreases with Fe doping, which can be directly correlated to transition tail width and grain size. Change in electronic structure with Fe doping has been examined by XAS study.

  10. Tailoring the dispersion behavior of optical nanowires with intercore-cladding lithium niobate thin film.

    Science.gov (United States)

    He, Hairong; Miao, Lili; Jiang, Guobao; Zhao, Chujun; Wen, Shuangchun

    2015-10-19

    The dispersion properties of silica and silicon subwavelength-diameter wires with intercore-cladding uniaxial dielectric lithium niobate thin film has been studied numerically in detail. The waveguide dispersion shifts centered around 1550-nm wavelength have been investigated. It shows that the dispersion of optical nanowires with intercore-cladding lithium niobate thin film is highly sensitive to fiber geometry. Moreover, with applied electric field, considerable dispersion shifts without changing its geometric structure can be obtained. Our work may provide an inroad for developing miniaturized functional optoelectronic devices.

  11. Optical switching and photoluminescence in erbium-implanted vanadium dioxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Herianto, E-mail: mail@heriantolim.com; Stavrias, Nikolas; Johnson, Brett C.; McCallum, Jeffrey C. [School of Physics, University of Melbourne, Parkville, Victoria 3010 (Australia); Marvel, Robert E.; Haglund, Richard F. [Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37240 (United States)

    2014-03-07

    Vanadium dioxide (VO{sub 2}) is under intensive consideration for optical switching due to its reversible phase transition, which features a drastic and rapid shift in infrared reflectivity. Classified as an insulator–to–metal transition, the phase transition in VO{sub 2} can be induced thermally, electrically, and optically. When induced optically, the transition can occur on sub-picosecond time scales. It is interesting to dope VO{sub 2} with erbium ions (Er{sup 3+}) and observe their combined properties. The first excited-state luminescence of Er{sup 3+} lies within the wavelength window of minimal transmission-loss in silicon and has been widely utilized for signal amplification and generation in silicon photonics. The incorporation of Er{sup 3+} into VO{sub 2} could therefore result in a novel photonic material capable of simultaneous optical switching and amplification. In this work, we investigate the optical switching and photoluminescence in Er-implanted VO{sub 2} thin films. Thermally driven optical switching is demonstrated in the Er-implanted VO{sub 2} by infrared reflectometry. Photoluminescence is observed in the thin films annealed at ∼800 °C or above. In addition, Raman spectroscopy and a statistical analysis of switching hysteresis are carried out to assess the effects of the ion implantation on the VO{sub 2} thin films. We conclude that Er-implanted VO{sub 2} can function as an optical switch and amplifier, but with reduced switching quality compared to pure VO{sub 2}.

  12. THIN CURRENT SHEETS AND ASSOCIATED ELECTRON HEATING IN TURBULENT SPACE PLASMA

    Energy Technology Data Exchange (ETDEWEB)

    Chasapis, A.; Retinò, A.; Sahraoui, F.; Canu, P. [Laboratoire de Physique des Plasmas, Ecole Polytechnique, Palaiseau, F-91128 (France); Vaivads, A.; Khotyaintsev, Yu. V. [Swedish Institute of Space Physics, Uppsala (Sweden); Sundkvist, D. [Space Sciences Laboratory, University of California, Berkeley, CA (United States); Greco, A. [Dipartimento di Fisica, Universita della Calabria (Italy); Sorriso-Valvo, L., E-mail: alexandros.chasapis@lpp.polytechnique.fr [IMIP-CNR, U.O.S. LICRYL di Cosenza (Italy)

    2015-05-01

    Intermittent structures, such as thin current sheets, are abundant in turbulent plasmas. Numerical simulations indicate that such current sheets are important sites of energy dissipation and particle heating occurring at kinetic scales. However, direct evidence of dissipation and associated heating within current sheets is scarce. Here, we show a new statistical study of local electron heating within proton-scale current sheets by using high-resolution spacecraft data. Current sheets are detected using the Partial Variance of Increments (PVI) method which identifies regions of strong intermittency. We find that strong electron heating occurs in high PVI (>3) current sheets while no significant heating occurs in low PVI cases (<3), indicating that the former are dominant for energy dissipation. Current sheets corresponding to very high PVI (>5) show the strongest heating and most of the time are consistent with ongoing magnetic reconnection. This suggests that reconnection is important for electron heating and dissipation at kinetic scales in turbulent plasmas.

  13. Thin Current Sheets and Associated Electron Heating in Turbulent Space Plasma

    Science.gov (United States)

    Chasapis, A.; Retinò, A.; Sahraoui, F.; Vaivads, A.; Khotyaintsev, Yu. V.; Sundkvist, D.; Greco, A.; Sorriso-Valvo, L.; Canu, P.

    2015-05-01

    Intermittent structures, such as thin current sheets, are abundant in turbulent plasmas. Numerical simulations indicate that such current sheets are important sites of energy dissipation and particle heating occurring at kinetic scales. However, direct evidence of dissipation and associated heating within current sheets is scarce. Here, we show a new statistical study of local electron heating within proton-scale current sheets by using high-resolution spacecraft data. Current sheets are detected using the Partial Variance of Increments (PVI) method which identifies regions of strong intermittency. We find that strong electron heating occurs in high PVI (>3) current sheets while no significant heating occurs in low PVI cases (5) show the strongest heating and most of the time are consistent with ongoing magnetic reconnection. This suggests that reconnection is important for electron heating and dissipation at kinetic scales in turbulent plasmas.

  14. Thin Film Formation of Gallium Nitride Using Plasma-Sputter Deposition Technique

    Directory of Open Access Journals (Sweden)

    R. Flauta

    2003-06-01

    Full Text Available The formation of gallium nitride (GaN thin film using plasma-sputter deposition technique has beenconfirmed. The GaN film deposited on a glass substrate at an optimum plasma condition has shown x-raydiffraction (XRD peaks at angles corresponding to that of (002 and (101 reflections of GaN. The remainingmaterial on the sputtering target exhibited XRD reflections corresponding to that of bulk GaN powder. Toimprove the system’s base pressure, a new UHV compatible system is being developed to minimize theimpurities in residual gases during deposition. The sputtering target configuration was altered to allow themonitoring of target temperature using a molybdenum (Mo holder, which is more stable against Gaamalgam formation than stainless steel.

  15. Synthesis, microstructural, optical and mechanical properties of yttria stabilized zirconia thin films

    Energy Technology Data Exchange (ETDEWEB)

    Amezaga-Madrid, P.; Hurtado-Macias, A.; Antunez-Flores, W.; Estrada-Ortiz, F.; Piza-Ruiz, P. [Centro de Investigacion en Materiales Avanzados S. C., and Laboratorio Nacional de Nanotecnologia. Miguel de Cervantes 120, Chihuahua, Chih., C.P. 31109 (Mexico); Miki-Yoshida, M., E-mail: mario.miki@cimav.edu.mx [Centro de Investigacion en Materiales Avanzados S. C., and Laboratorio Nacional de Nanotecnologia. Miguel de Cervantes 120, Chihuahua, Chih., C.P. 31109 (Mexico)

    2012-09-25

    Highlights: Black-Right-Pointing-Pointer Thin films of YSZ obtained by AACVD have high quality. Black-Right-Pointing-Pointer They are uniform, very transparent, and have high hardness. Black-Right-Pointing-Pointer Optical characterization were performed in detail, optical constants and band gap energy were determined as a function of dopant content. - Abstract: Thin films of yttria-stabilized zirconia (YSZ) exhibit exceptional properties, such as high thermal, chemical and mechanical stability. Here, we report the synthesis of YSZ thin films by aerosol assisted chemical vapour deposition onto borosilicate glass and fused silica substrates. Optimum deposition temperature was 673 {+-} 5 K. In addition, different Y content was tried to analyse its influence in the microstructure and properties of the films. The films were uniform, transparent and non-light scattering. Surface morphology and cross sectional microstructure were studied by field emission scanning electron microscopy. The microstructure of the films was characterized by grazing incidence X-ray diffraction. Crystallite size and lattice parameter were obtained. Optical properties were analysed from reflectance and transmittance spectra; from these measurements, optical constants and band gap were obtained. Quantum confinement effect, due to the small grain size of the films, was evident in the high band gap energy obtained. Nanoindentation tests were realized at room temperature employing the continuous stiffness measurement method, to determine the hardness and elastic modulus as a function of Y content.

  16. Conformal self-assembled thin films for optical pH sensors

    Science.gov (United States)

    Topasna, Daniela M.; Topasna, Gregory A.; Liu, Minghanbo; Tseng, Ching-Hung

    2016-04-01

    Simple, reliable, lightweight, and inexpensive thin films based sensors are still in intense development and high demand in many applications such as biomedical, industrial, environmental, military, and consumer products. One important class of sensors is the optical pH sensor. In addition, conformal thin film based sensors extend the range of application for pH optical sensors. We present the results on the fabrication and characterization of optical pH sensing coatings made through ionic self-assembled technique. These thin films are based on the combination of a polyelectrolyte and water-soluble organic dye molecule Direct Yellow 4. A series of films was fabricated and characterized in order to determine the optimized parameters of the polymer and of the organic dye solutions. The optical pH responses of these films were also studied. The transparent films were immersed in solutions at various temperature and pH values. The films are stable when immersed in solutions with pH below 9.0 and temperatures below 90 °C and they maintain their performance after longer immersion times. We also demonstrate the functionality of these coatings as conformal films.

  17. Hydrogen plasma treatment for improved conductivity in amorphous aluminum doped zinc tin oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Morales-Masis, M., E-mail: monica.moralesmasis@epfl.ch; Ding, L.; Dauzou, F. [Photovoltaics and Thin-Film Electronics Laboratory (PVLab), Institute of Microengineering (IMT), Ecole Polytechnique Fédérale de Lausanne - EPFL, Rue de la Maladière 71b, CH-2002 Neuchatel (Switzerland); Jeangros, Q. [Interdisciplinary Centre for Electron Microscopy, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne (Switzerland); Hessler-Wyser, A. [Photovoltaics and Thin-Film Electronics Laboratory (PVLab), Institute of Microengineering (IMT), Ecole Polytechnique Fédérale de Lausanne - EPFL, Rue de la Maladière 71b, CH-2002 Neuchatel (Switzerland); Interdisciplinary Centre for Electron Microscopy, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne (Switzerland); Nicolay, S. [Centre Suisse d’Electronique et de Microtechnique (CSEM) SA, Rue Jaquet-Droz 1, CH-2002 Neuchatel (Switzerland); Ballif, C. [Photovoltaics and Thin-Film Electronics Laboratory (PVLab), Institute of Microengineering (IMT), Ecole Polytechnique Fédérale de Lausanne - EPFL, Rue de la Maladière 71b, CH-2002 Neuchatel (Switzerland); Centre Suisse d’Electronique et de Microtechnique (CSEM) SA, Rue Jaquet-Droz 1, CH-2002 Neuchatel (Switzerland)

    2014-09-01

    Improving the conductivity of earth-abundant transparent conductive oxides (TCOs) remains an important challenge that will facilitate the replacement of indium-based TCOs. Here, we show that a hydrogen (H{sub 2})-plasma post-deposition treatment improves the conductivity of amorphous aluminum-doped zinc tin oxide while retaining its low optical absorption. We found that the H{sub 2}-plasma treatment performed at a substrate temperature of 50 °C reduces the resistivity of the films by 57% and increases the absorptance by only 2%. Additionally, the low substrate temperature delays the known formation of tin particles with the plasma and it allows the application of the process to temperature-sensitive substrates.

  18. Metal-insulator transition in epitaxial NdNiO3 thin film: A structural, electrical and optical study

    Science.gov (United States)

    Shao, Tao; Qi, Zeming; Wang, Yuyin; Li, Yuanyuan; Yang, Mei; Hu, Chuansheng

    2017-03-01

    NdNiO3 thin film has been prepared by pulsed laser deposition on LaAlO3 (001) single crystalline substrate. Temperature-dependent resistivity measurement shows a sharp metal-insulator transition in such thin film. The phase transition temperature can be tuned from 90 K to 121 K by changing the thickness of thin film. The structure evolution during phase transition is studied by Raman spectroscopy. Optical conductivity reveals that the variation carrier density in the process of phase transition. The results of structural, electrical and optical studies provide useful insights to understand the mechanism of metal-insulator transition of NdNiO3 thin film.

  19. A correlation of thin lens approximation to thick lens design by using context based method in optics education

    Science.gov (United States)

    Farsakoglu, O. F.; Inal Atik, Ipek; Kocabas, Hikmet

    2014-07-01

    The effect of Coddington factors on aberration functions has been analysed using thin lens approximation with optical glass parameters. The dependence of spherical aberration on Coddington shape factor for the various optical glasses in real lens design was discussed using exact ray tracing for the optics education and training purposes. Thin lens approximation and thick lens design are generally taught with only lecturing method. But, thick lens design is closely related to the real life. Hence, it is more appropriate to teach thin lens approximation and thick lens design with real-life context based approach. Context based teaching can be effective in solving problems in which the subject is very difficult and irrelevant. It also provides extensive evidence for optics education that students are generally unable to correctly apply the concepts of lens design to optical instruments currently used. Therefore, the outline of real-life context based thick lens design lessons were proposed and explained in detail considering thin lens approximation.

  20. Optical patterning of photosensitive thin film silica mesophases

    Energy Technology Data Exchange (ETDEWEB)

    DOSHI,DHAVAL A.; HUESING,NICOLA K.; LU,MENGCHENG; FAN,HONGYOU; HURD,ALAN J.; BRINKER,C. JEFFREY

    2000-02-09

    Photosensitive films incorporating molecular photoacid generators compartmentalized within a silica-surfactant mesophase were prepared by an evaporation-induced self-assembly process. UV-exposure promoted localized acid-catalyzed siloxane condensation, enabling selective etching of unexposed regions, thereby serving as a resistless technique to prepare patterned mesoporous silica. The authors also demonstrated an optically-defined mesophase transformation (hexagonal {r_arrow} tetragonal) and patterning of refractive index and wetting behavior. Spatial control of structure and function on the macro- and mesoscales is of interest for sensor arrays, nano-reactors, photonic and fluidic devices, and low dielectric constant films. More importantly, it extends the capabilities of conventional lithography from spatially defining the presence or absence of film to spatial control of film structure and function.

  1. Hybrid enabled thin film metrology using XPS and optical

    Science.gov (United States)

    Vaid, Alok; Iddawela, Givantha; Mahendrakar, Sridhar; Lenahan, Michael; Hossain, Mainul; Timoney, Padraig; Bello, Abner F.; Bozdog, Cornel; Pois, Heath; Lee, Wei Ti; Klare, Mark; Kwan, Michael; Kang, Byung Cheol; Isbester, Paul; Sendelbach, Matthew; Yellai, Naren; Dasari, Prasad; Larson, Tom

    2016-03-01

    Complexity of process steps integration and material systems for next-generation technology nodes is reaching unprecedented levels, the appetite for higher sampling rates is on the rise, while the process window continues to shrink. Current thickness metrology specifications reach as low as 0.1A for total error budget - breathing new life into an old paradigm with lower visibility for past few metrology nodes: accuracy. Furthermore, for advance nodes there is growing demand to measure film thickness and composition on devices/product instead of surrogate planar simpler pads. Here we extend our earlier work in Hybrid Metrology to the combination of X-Ray based reference technologies (high performance) with optical high volume manufacturing (HVM) workhorse metrology (high throughput). Our stated goal is: put more "eyes" on the wafer (higher sampling) and enable move to films on pattern structure (control what matters). Examples of 1X front-end applications are used to setup and validate the benefits.

  2. Preparation of Magneto-Optic Ce:YIG Thin Films for Integrated Optical Isolator

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    This paper presents the growth of cerium substituted YIG (Ce1 YIG) thin films on silica substrate.The large Faraday rotation coefficient and strong in-plane anisotropy were observed. The film is desirable for waveguide configuration isolator application.

  3. Conductive polythiophene-like thin film synthesized using controlled plasma processes

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Long [Department of Advanced Materials Science and Engineering, Nu-SKKU Joint Institute for Plasma Nano Materials, Center for Advanced Plasma Surface Technology, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Jeong, Dong-Cheol [Department of Chemistry, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Chemical and Biological Defense Research Center, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Javid, Amjed [Department of Advanced Materials Science and Engineering, Nu-SKKU Joint Institute for Plasma Nano Materials, Center for Advanced Plasma Surface Technology, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Kim, Sanghoon [Department of Energy Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Nam, Jae-Do [Department of Energy Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Department of Polymer Science and Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Song, Changsik [Department of Chemistry, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Chemical and Biological Defense Research Center, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Han, Jeon Geon, E-mail: hanjg@skku.edu [Department of Advanced Materials Science and Engineering, Nu-SKKU Joint Institute for Plasma Nano Materials, Center for Advanced Plasma Surface Technology, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2015-07-31

    Transparent conductive polythiophene-like thin films were synthesized by a plasma polymerization technique using a middle range frequency (40 kHz). The effects of the variation of power and pressure on the chemical structure of the deposited film were investigated along with the effect of doping with iodine vapors on the conductivity of the films. Plasma polymerization is a low temperature process, provides deposition of thin polymer films on a wide variety of substrates, and has advantages due to non-involvement of any solvents. The chemical structure of the films was characterized using Fourier Transform Infrared Spectroscopy. The wetting properties of the films were studied using water contact angle measurements. The fragmentation of the thiophene monomer structure increased with increasing discharge power, implying that at low discharge power, the plasma phase was energy-deficient. The lower fragmentation of the monomer led to high retention of the monomer structure in the deposited films. Under various pressure conditions, the retention of the monomer structure was found to be similar as that of the deposited films. After doping with iodine vapor, a large conductivity enhancement, from 3.52 × 10{sup −6} to 2.3 × 10{sup −3} s/cm was observed. The results showed the retention of a monomer structure having conjugated bonds in the films, responsible for the enhanced conductivities. - Highlights: • Fabrication of conductive polythiophene-like films by plasma process • Transmittance more than 80% • 3 order conductivity enhancement with iodine doping • Retention of monomer structure responsible for better conductivities.

  4. Fabrication of Au/graphene oxide/Ag sandwich structure thin film and its tunable energetics and tailorable optical properties

    Directory of Open Access Journals (Sweden)

    Ruijin Hong

    2017-01-01

    Full Text Available Au/graphene oxide/Ag sandwich structure thin film was fabricated. The effects of graphene oxide (GO and bimetal on the structure and optical properties of metal silver films were investigated by X-ray diffraction (XRD, optical absorption, and Raman intensity measurements, respectively. Compared to silver thin film, Au/graphene oxide/Ag sandwich structure composite thin films were observed with wider optical absorption peak and enhanced absorption intensity. The Raman signal for Rhodamine B molecules based on the Au/graphene oxide/Ag sandwich nanostructure substrate were obviously enhanced due to the bimetal layer and GO layer with tunable absorption intensity and fluorescence quenching effects.

  5. The changes in optical absorbance of ZrO{sub 2} thin film with the rise of the absorbed dose

    Energy Technology Data Exchange (ETDEWEB)

    Abayli, D., E-mail: abayli@itu.edu.tr; Baydogan, N., E-mail: dogannil@itu.edu.tr [Energy Institute, Istanbul Technical University, Ayazaga Campus, 34469, Istanbul (Turkey)

    2016-03-25

    In this study, zirconium oxide (ZrO{sub 2}) thin film samples prepared by sol–gel method were irradiated using Co-60 radioisotope as gamma source. Then, it was investigated the ionizing effect on optical properties of ZrO{sub 2} thin film samples with the rise of the absorbed dose. The changes in the optical absorbance of ZrO{sub 2} thin films were determined by using optical transmittance and the reflectance measurements in the range between 190 – 1100 nm obtained from PG Instruments T80 UV-Vis spectrophotometer.

  6. Plasma interactions determine the composition in pulsed laser deposited thin films

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jikun; Stender, Dieter; Conder, Kazimierz; Wokaun, Alexander; Schneider, Christof W.; Lippert, Thomas, E-mail: thomas.lippert@psi.ch [Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland); Döbeli, Max [Laboratory of Ion Beam Physics, ETH Zurich, CH-8093 Zurich (Switzerland)

    2014-09-15

    Plasma chemistry and scattering strongly affect the congruent, elemental transfer during pulsed laser deposition of target metal species in an oxygen atmosphere. Studying the plasma properties of La{sub 0.6}Sr{sub 0.4}MnO{sub 3}, we demonstrate for as grown La{sub 0.6}Sr{sub 0.4}MnO{sub 3-δ} films that a congruent transfer of metallic species is achieved in two pressure windows: ∼10{sup −3} mbar and ∼2 × 10{sup −1} mbar. In the intermediate pressure range, La{sub 0.6}Sr{sub 0.4}MnO{sub 3-δ} becomes cation deficient and simultaneously almost fully stoichiometric in oxygen. Important for thin film growth is the presence of negative atomic oxygen and under which conditions positive metal-oxygen ions are created in the plasma. This insight into the plasma chemistry shows why the pressure window to obtain films with a desired composition and crystalline structure is narrow and requires a careful adjustment of the process parameters.

  7. Measuring atomic oxygen densities and electron properties in an Inductively Coupled Plasma for thin film deposition

    Science.gov (United States)

    Meehan, David; Gibson, Andrew; Booth, Jean-Paul; Wagenaars, Erik

    2016-09-01

    Plasma Enhanced Pulsed Laser Deposition (PE-PLD) is an advanced way of depositing thin films of oxide materials by using a laser to ablate a target, and passing the resulting plasma plume through a background Inductively-Coupled Plasma (ICP), instead of a background gas as is done in traditional PLD. The main advantage of PE-PLD is the control of film stoichiometry via the direct control of the reactive oxygen species in the ICP instead of relying on a neutral gas background. The aim is to deposit zinc oxide films from a zinc metal target and an oxygen ICP. In this work, we characterise the range of compositions of the reactive oxygen species achievable in ICPs; in particular the atomic oxygen density. The density of atomic oxygen has been determined within two ICPs of two different geometries over a range of plasma powers and pressures with the use of Energy Resolved Actinometry (ERA). ERA is a robust diagnostic technique with determines both the dissociation degree and average electron energy by comparing the excitation ratios of two oxygen and one argon transition. Alongside this the electron densities have been determined with the use of a hairpin probe. This work received financial support from the EPSRC, and York-Paris CIRC.

  8. RF plasma enhanced MOCVD of yttria stabilized zirconia thin films using octanedionate precursors and their characterization

    Energy Technology Data Exchange (ETDEWEB)

    Chopade, S.S. [Laser and Plasma Technology Division, Bhabha Atomic Research Center, Trombay, Mumbai 400085 (India); Nayak, C.; Bhattacharyya, D.; Jha, S.N.; Tokas, R.B.; Sahoo, N.K. [Atomic & Molecular Physics Division, Bhabha Atomic Research Center, Trombay, Mumbai 400085 (India); Deo, M.N. [High Pressure & Synchrotron Radiation Physics Division, Bhabha Atomic Research Center, Trombay, Mumbai 400085 (India); Biswas, A. [Atomic & Molecular Physics Division, Bhabha Atomic Research Center, Trombay, Mumbai 400085 (India); Rai, Sanjay [Indus Synchrotron Utilization Division, RRCAT, Indore 452013 (India); Thulasi Raman, K.H.; Rao, G.M. [Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore 560012 (India); Kumar, Niranjan [Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Patil, D.S., E-mail: dspatil@iitb.ac.in [Laser and Plasma Technology Division, Bhabha Atomic Research Center, Trombay, Mumbai 400085 (India)

    2015-11-15

    Highlights: • YSZ films are deposited by RF plasma MOCVD using Zr(tod){sub 4} and Y(tod){sub 3} precursors. • Films are deposited under the influence of RF self-bias on the substrates. • Films are characterized by different techniques. • Films properties are dependent on yttria content and film structure. - Abstract: Yttria stabilized zirconia thin films have been deposited by RF plasma enhanced MOCVD technique on silicon substrates at substrate temperature of 400 °C. Plasma of precursor vapors of (2,7,7-trimethyl-3,5-octanedionate) yttrium (known as Y(tod){sub 3}), (2,7,7-trimethyl-3,5-octanedionate) zirconium (known as Zr(tod){sub 4}), oxygen and argon gases is used for deposition. To the best of our knowledge, plasma assisted MOCVD of YSZ films using octanediaonate precursors have not been reported in the literature so far. The deposited films have been characterized by GIXRD, FTIR, XPS, FESEM, AFM, XANES, EXAFS, EDAX and spectroscopic ellipsometry. Thickness of the films has been measured by stylus profilometer while tribological property measurement has been done to study mechanical behavior of the coatings. Characterization by different techniques indicates that properties of the films are dependent on the yttria content as well as on the structure of the films.

  9. Microwave plasma-assisted ALD of Al2O3 thin films: a study on the substrate temperature dependence of various parameters of interest

    Science.gov (United States)

    Thomas, Subin; Nalini, Savitha; Kumar, K. Rajeev

    2017-03-01

    This study utilizes microwave plasma-assisted atomic layer deposition (MPALD) in remote mode to deposit Al2O3 thin films with increased growth per cycle (GPC). Optical emission spectroscopy (OES) was used to identify the plasma configuration in the ALD chamber. MPALD-Al2O3 thin films were deposited at temperatures ranging from room temperature to 200 °C and the electrical parameters were investigated with Al/Al2O3/p-Si metal oxide semiconductor (MOS) structures. A GPC of 0.24 nm was observed for the films deposited at room temperature. The fixed oxide charge densities ( N fix) in all films were of the order of 1012 cm-2. The interface state density ( D it) exhibited a distinct minimum for the films deposited at 100 °C. The dependence of built-in voltage, N fix, and D it on Al2O3 deposition temperature was investigated. This can be used as a measure of the electrical applicability of these thin films.

  10. Programmable Bidirectional Folding of Metallic Thin Films for 3D Chiral Optical Antennas.

    Science.gov (United States)

    Mao, Yifei; Zheng, Yun; Li, Can; Guo, Lin; Pan, Yini; Zhu, Rui; Xu, Jun; Zhang, Weihua; Wu, Wengang

    2017-03-10

    3D structures with characteristic lengths ranging from nanometer to micrometer scale often exhibit extraordinary optical properties, and have been becoming an extensively explored field for building new generation nanophotonic devices. Albeit a few methods have been developed for fabricating 3D optical structures, constructing 3D structures with nanometer accuracy, diversified materials, and perfect morphology is an extremely challenging task. This study presents a general 3D nanofabrication technique, the focused ion beam stress induced deformation process, which allows a programmable and accurate bidirectional folding (-70°-+90°) of various metal and dielectric thin films. Using this method, 3D helical optical antennas with different handedness, improved surface smoothness, and tunable geometries are fabricated, and the strong optical rotation effects of single helical antennas are demonstrated.

  11. Optical properties of organic thin films of 4-tricyanovinyl-{N}, {N}-diethylaniline

    Science.gov (United States)

    El-Nahass, M. M.; Abd-El-Rahman, K. F.; Darwish, A. A. A.

    2009-11-01

    Optical properties of 4-tricyanovinyl-N, N-diethylaniline thin films were investigated using spectrophotometric measurement of transmittance and reflectance at normal incidence of light in the wavelength range of 200-2500 nm. The optical constants (refractive index, n, and absorption index, k) were calculated using a computer program based on Murmann's exact equations. The calculated optical constants are independent of the film thickness and their values are decreased by annealing temperature. The optical dispersion parameters have been analysed by single oscillator model. The type of transition in as-deposited films is indirect allowed with a value of energy gap equals to 1.45 eV, which increased to 1.51 eV upon annealing. in here

  12. Structural, morphological, optical and electrical properties of spray deposited lithium doped CdO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Velusamy, P.; Babu, R. Ramesh, E-mail: rampap2k@yahoo.co.in [Crystal Growth and Thin Films Laboratory, Department of Physics, Bharathidasan University, Tiruchirappalli-620 024, Tamil Nadu (India); Ramamurthi, K. [Crystal Growth and Thin Films Laboratory, Department of Physics and Nanotechnology, Faculty of Engineering and Technology, SRM University, Kattankulathur – 603 203, Tamil Nadu (India)

    2016-05-23

    In the present work, CdO and Li doped CdO thin films were deposited on microscopic glass substrates at 300°C by a spray pyrolysis experimental setup. The deposited CdO and Li doped CdO thin films were subjected to XRD, SEM, UV-VIS spectroscopy and Hall measurement analyses. XRD studies revealed the polycrystalline nature of the deposited films and confirmed that the deposited CdO and Li doped CdO thin films belong to cubic crystal system. The Scanning electron microscopy analysis revealed the information on shape of CdO and Li doped CdO films. Electrical study reveals the n-type semiconducting nature of CdO and the optical band gap is varied between 2.38 and 2.44 eV, depending on the Li doping concentrations.

  13. Structural, morphological, optical and electrical properties of spray deposited lithium doped CdO thin films

    Science.gov (United States)

    Velusamy, P.; Babu, R. Ramesh; Ramamurthi, K.

    2016-05-01

    In the present work, CdO and Li doped CdO thin films were deposited on microscopic glass substrates at 300˚C by a spray pyrolysis experimental setup. The deposited CdO and Li doped CdO thin films were subjected to XRD, SEM, UV-VIS spectroscopy and Hall measurement analyses. XRD studies revealed the polycrystalline nature of the deposited films and confirmed that the deposited CdO and Li doped CdO thin films belong to cubic crystal system. The Scanning electron microscopy analysis revealed the information on shape of CdO and Li doped CdO films. Electrical study reveals the n-type semiconducting nature of CdO and the optical band gap is varied between 2.38 and 2.44 eV, depending on the Li doping concentrations.

  14. Enhanced optical absorption by Ag nanoparticles in a thin film Si solar cell

    Institute of Scientific and Technical Information of China (English)

    Chen Feng-Xiang; Wang Li-Sheng; Xu Wen-Ying

    2013-01-01

    Thin film solar cells have the potential to significantly reduce the cost of photovoltaics.Light trapping is crucial to such a thin film silicon solar cell because of a low absorption coefficient due to its indirect band gap.In this paper,we investigate the suitability of surface plasmon resonance Ag nanoparticles for enhancing optical absorption in the thin film solar cell.For evaluating the transmittance capability of Ag nanoparticles and the conventional antireflection film,an enhanced transmittance factor is introduced.We find that under the solar spectrum AM1.5,the transmittance of Ag nanoparticles with radius over 160 nm is equivalent to that of conventional textured antireflection film,and its effect is better than that of the planar antireflection film.The influence of the surrounding medium is also discussed.

  15. Dip coated nickel zinc oxide thin films: Structural, optical and magnetic investigations

    Science.gov (United States)

    Kayani, Zohra Nazir; Kiran, Faiza; Riaz, Saira; Zia, Rehana; Naseem, Shahzad

    2015-01-01

    Dip-coating technique was used to deposit NiZnO thin films on glass substrates at varying withdrawal speed in the range of 150-350 mm/s and annealed at 500 °C for 4 h. X-ray diffraction (XRD) results showed that the deposited NiZnO thin films have a pure wurtzite structure without any significant change in the structure caused by substituting Zn ion with Ni ion. Crystallite size increased from 248 to 497 nm with increase in withdrawal speed. Vibrating Sample magnetometer (VSM) results indicated that NiZnO thin films exhibit ferromagnetic properties. Increase in saturation magnetization with increase in withdrawal speed is observed. Evaluated optical band gap of the films reduced from 3.18 eV to 2.50 eV with the increase in withdrawal speed of the substrate.

  16. Characterization of bioactive RGD peptide immobilized onto poly(acrylic acid) thin films by plasma polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Hyun Suk; Ko, Yeong Mu; Shim, Jae Won [Department of Dental Materials, School of Dentistry, MRC Center, Chosun University, Gwangju (Korea, Republic of); Lim, Yun Kyong; Kook, Joong-Ki [Department of Oral Biochemistry, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Cho, Dong-Lyun [School of Applied Chemical Engineering and Center for Functional Nano Fine Chemicals, Chonnam National University, Gwangju (Korea, Republic of); Kim, Byung Hoon, E-mail: kim5055@chosun.ac.kr [Department of Dental Materials, School of Dentistry, MRC Center, Chosun University, Gwangju (Korea, Republic of)

    2010-11-01

    Plasma surface modification can be used to improve the surface properties of commercial pure Ti by creating functional groups to produce bioactive materials with different surface topography. In this study, a titanium surface was modified with acrylic acid (AA) using a plasma treatment and immobilized with bioactive arginine-glycine-aspartic acid (RGD) peptide, which may accelerate the tissue integration of bone implants. Both terminals containing the -NH{sub 2} of RGD peptide sequence and -COOH of poly(acrylic acid) (PAA) thin film were combined with a covalent bond in the presence of 1-ethyl-3-3-dimethylaminopropyl carbodiimide (EDC). The chemical structure and morphology of AA film and RGD immobilized surface were investigated by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR), atomic force microscopy (AFM), and scanning electron microscopy (SEM). All chemical analysis showed full coverage of the Ti substrate with the PAA thin film containing COOH groups and the RGD peptide. The MC3T3-E1 cells were cultured on each specimen, and the cell alkaline phosphatase (ALP) activity were examined. The surface-immobilized RGD peptide has a significantly increased the ALP activity of MC3T3-E1 cells. These results suggest that the RGD peptide immobilization on the titanium surface has an effect on osteoblastic differentiation of MC3T3-E1 cells and potential use in osteo-conductive bone implants.

  17. Synthesis and Characterization of Nanofibrous Polyaniline Thin Film Prepared by Novel Atmospheric Pressure Plasma Polymerization Technique

    Directory of Open Access Journals (Sweden)

    Choon-Sang Park

    2016-01-01

    Full Text Available This work presents a study on the preparation of plasma-polymerized aniline (pPANI nanofibers and nanoparticles by an intense plasma cloud type atmospheric pressure plasma jets (iPC-APPJ device with a single bundle of three glass tubes. The nano size polymer was obtained at a sinusoidal wave with a peak value of 8 kV and a frequency of 26 kHz under ambient air. Discharge currents, photo-sensor amplifier, and optical emission spectrometer (OES techniques were used to analyze the plasma produced from the iPC-APPJ device. Field emission scanning electron microscopy (FE-SEM, transmission electron microscopy (TEM, Fourier transform infrared spectroscopy (FT-IR, gas chromatography-mass spectrometry (GC-MS, and gel permeation chromatography (GPC techniques were used to analyze the pPANI. FE-SEM and TEM results show that pPANI has nanofibers, nanoparticles morphology, and polycrystalline characteristics. The FT-IR and GC-MS analysis show the characteristic polyaniline peaks with evidence that some quinone and benzene rings are broken by the discharge energy. GPC results show that pPANI has high molecular weight (Mw, about 533 kDa with 1.9 polydispersity index (PDI. This study contributes to a better understanding on the novel growth process and synthesis of uniform polyaniline nanofibers and nanoparticles with high molecular weights using the simple atmospheric pressure plasma polymerization technique.

  18. Electronic excitation induced modifications of optical and morphological properties of PCBM thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, T. [Department of Physics and Materials Research Centre, Malaviya National Institute of Technology, Jaipur 302017 (India); Singhal, R., E-mail: rsinghal.phy@mnit.ac.in [Department of Physics and Materials Research Centre, Malaviya National Institute of Technology, Jaipur 302017 (India); Vishnoi, R. [Department of Physics and Materials Research Centre, Malaviya National Institute of Technology, Jaipur 302017 (India); Department of Physics, Vardhman (P.G.) College, Bijnor 246701, U.P. (India); Sharma, P. [Department of Physics and Materials Research Centre, Malaviya National Institute of Technology, Jaipur 302017 (India); Patra, A.; Chand, S. [National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi 110012 (India); Lakshmi, G.B.V.S. [Inter University Accelerator Centre, Post Box No. 10502, New Delhi 110067 (India); Biswas, S.K. [Department of Metallurgical and Materials Engineering, Malaviya National Institute of Technology, Jaipur 302017 (India)

    2016-07-15

    Highlights: • Spin casted PCBM thin films are irradiated by 90 MeV Ni{sup 7+} ion beam. • The decrease in band gap was found after irradiation. • There is a decomposition of molecular bond due to ion irradiation. • Roughness is also found to be dependent on incident ion fluence. - Abstract: Phenyl C{sub 61} butyric acid methyl ester (PCBM) is a fullerene derivative and most commonly used in organic photovoltaic devices both as electron acceptor and transporting material due to high electron mobility. PCBM is easy to spin caste on some substrate as it is soluble in chlorobenzene. In this study, the spin coated thin films of PCBM (on two different substrate, glass and double sided silicon) were irradiated using 90 MeV Ni{sup 7+} swift heavy ion beam at low fluences ranging from 1 × 10{sup 9} to 1 × 10{sup 11} ions/cm{sup 2} to study the effect of ion beam irradiation. The pristine and irradiated PCBM thin films were characterized by UV–visible absorption spectroscopy and fourier transform infrared spectroscopy (FTIR) to investigate the optical properties before and after irradiation. These thin films were further analyzed using atomic force microscopy (AFM) to investigate the morphological modifications which are induced by energetic ions. The variation in optical band gap after irradiation was measured using Tauc’s relation from UV–visible absorption spectra. A considerable change was observed with increasing fluence in optical band gap of irradiated thin films of PCBM with respect to the pristine film. The decrease in FTIR band intensity of C{sub 60} cage reveals the polymerization reaction due to high energy ion impact. The roughness is also found to be dependent on incident fluences. This study throws light for the application of PCBM in organic solar cells in form of ion irradiation induced nanowires of PCBM for efficient charge carrier transportation in active layer.

  19. DETERMINING OPTICAL CONSTANTS OF SELENIUM THIN FILMS USING THE ENVELOPE METHOD

    Directory of Open Access Journals (Sweden)

    Nehad M. Tashtoush

    2013-01-01

    Full Text Available Two Selenium thin films were deposited on glass substrates using thermal evaporation technique. The optical constants (refractive index, absorption coefficient and extinction coefficient and energy gap were calculated using the Transmittance (T spectrums of the films in the spectral range of 500-900 nm. The envelope method was used to determine optical constants. The calculated refractive index was found to be in the range of 2.60 to 2.85 and the Energy gap (Eg was found to be 1.8 eV which are in agreement with other studies made using other procedures. The films were found to be amorphous according to the results obtained by XRD technique. This method can be used to have a good results for many tranparent thin films with more mathematical tools.

  20. Correlations of electro-optical and nanostructural properties of CdTe thin films

    Science.gov (United States)

    Levi, D. H.; Moutinho, H. R.; Hasoon, F. S.; Ahrenkiel, R. K.; Kazmerski, L. L.; Al-Jassim, M. M.

    1996-01-01

    This paper presents correlations of macroscopic optical properties with the nanoscale physical and electronic structure of CdTe/CdS thin films used for photovoltaic cell fabrication. We have studied the evolution of these properties under systematic variation of post-growth treatment conditions for several standard deposition techniques. The electro-optical properties and nanostructure depend strongly on deposition conditions and post-growth treatments. Our results indicate that the standard CdCl2—heat treatment enhances grain size and passivates defects. We have also found strong evidence for sulfur diffusion across the CdTe—CdS interface. This interdiffusion produces a thin layer at the junction with a bandgap lower than the rest of the absorber layer. This effect could have important implications for photoexcited carrier collection in photovoltaic applications.

  1. Correlations of electro-optical and nanostructural properties of CdTe thin films

    Energy Technology Data Exchange (ETDEWEB)

    Levi, D.H.; Moutinho, H.R.; Hasoon, F.S.; Ahrenkiel, R.K.; Kazmerski, L.L.; Al-Jassim, M.M. [National Renewable Energy Laboratory, 1617 Cole Blvd., Golden, Colorado 80401 (United States)

    1996-01-01

    This paper presents correlations of macroscopic optical properties with the nanoscale physical and electronic structure of CdTe/CdS thin films used for photovoltaic cell fabrication. We have studied the evolution of these properties under systematic variation of post-growth treatment conditions for several standard deposition techniques. The electro-optical properties and nanostructure depend strongly on deposition conditions and post-growth treatments. Our results indicate that the standard CdCl{sub 2}{emdash}heat treatment enhances grain size and passivates defects. We have also found strong evidence for sulfur diffusion across the CdTe{emdash}CdS interface. This interdiffusion produces a thin layer at the junction with a bandgap lower than the rest of the absorber layer. This effect could have important implications for photoexcited carrier collection in photovoltaic applications. {copyright} {ital 1996 American Institute of Physics.}

  2. Effect of the thin-film limit on the measurable optical properties of graphene.

    Science.gov (United States)

    Holovský, Jakub; Nicolay, Sylvain; De Wolf, Stefaan; Ballif, Christophe

    2015-10-28

    The fundamental sheet conductance of graphene can be directly related to the product of its absorption coefficient, thickness and refractive index. The same can be done for graphene's fundamental opacity if the so-called thin-film limit is considered. Here, we test mathematically and experimentally the validity of this limit on graphene, as well as on thin metal and semiconductor layers. Notably, within this limit, all measurable properties depend only on the product of the absorption coefficient, thickness, and refractive index. As a direct consequence, the absorptance of graphene depends on the refractive indices of the surrounding media. This explains the difficulty in determining separately the optical constants of graphene and their widely varying values found in literature so far. Finally, our results allow an accurate estimation of the potential optical losses or gains when graphene is used for various optoelectronic applications.

  3. Effect of chlorine doping on electrical and optical properties of ZnO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Chikoidze, E. [Groupe d' Etude de la Matiere Condensee (GEMaC), CNRS, Universite de Versailles-Saint-Quentin, 1 Place Aristide Briand. 92195 Meudon Cedex (France)], E-mail: Ekaterina.chikoidze@cnrs-bellevue.fr; Nolan, M.; Modreanu, M. [Tyndall National Institute, University College Cork, Lee Maltings, Prospect Row, Cork (Ireland); Sallet, V.; Galtier, P. [Groupe d' Etude de la Matiere Condensee (GEMaC), CNRS, Universite de Versailles-Saint-Quentin, 1 Place Aristide Briand. 92195 Meudon Cedex (France)

    2008-09-30

    Chlorine doped ZnO thin films were grown by metal-organic chemical vapour deposition (MOCVD) on sapphire and fused silica substrates. Chlorine is incorporated by substitution of oxygen and acts as a donor, leading to an increase of electron concentration. Transport properties were studied for ZnO thin films with different chlorine content. Hall effect measurements show an increase of electron carrier concentration and a decrease of electron mobility upon increasing the amount of chlorine incorporated in ZnO. The lowest resistivity {rho} = 3.6 x 10{sup -3} {omega} cm was obtained for layers deposited on sapphire substrate. UV-VIS-NIR spectroscopy has been used for the study of optical properties. For all samples, the optical transmittance in the visible range is greater than 80%. First principles computations were applied in order to examine the change in the band gap of ZnO with Cl doping.

  4. Structural and Optical Study of Chemical Bath Deposited Nano-Structured CdS Thin Films

    Science.gov (United States)

    Kumar, Suresh; Sharma, Dheeraj; Sharma, Pankaj; Sharma, Vineet; Barman, P. B.; Katyal, S. C.

    2011-12-01

    CdS is commonly used as window layer in polycrystalline solar cells. The paper presents a structural and optical study of CdS nano-structured thin films. High quality CdS thin films are grown on commercial glass by means of chemical bath deposition. It involves an alkaline solution of cadmium salt, a complexant, a chalcogen source and a non-ionic surfactant. The films have been prepared under various process parameters. The chemically deposited films are annealed to estimate its effect on the structural and optical properties of films. These films (as -deposited and annealed) have been characterized by means of XRD, SEM and UV-Visible spectrophotometer. XRD of films show the nano-crystalline nature. The energy gap of films is found to be of direct in nature.

  5. Optical constants of thermally evaporated As10Te10S80 thin films

    Science.gov (United States)

    Moharram, A. H.

    The transmission spectra of thermally evaporated As10Te10S80 thin films were measured over the wavelength range 300 to 900 nm. A simple method, suggested by Swanepoel, was used for the determination of the optical constants and thickness of the film. The absorption edge is described using the non-direct transition model proposed by Tauc. The effect of one hour's thermal annealing in the temperatures range 300-475 K on the optical properties of the As10Te10S80 film is reported and explained.

  6. Glass Difractive Optical Elements (DOEs with complex modulation DLC thin film coated

    Directory of Open Access Journals (Sweden)

    Marina Sparvoli

    2008-09-01

    Full Text Available We developed a complex (amplitude and phase modulation Diffractive Optical Element (DOE with four phase levels, which is based in a glass substrate coated with DLC (Diamond Like Carbon thin film as the amplitude modulator. The DLC film was deposited by magnetron reactive sputtering with a graphite target and methane gas in an optical glass surface. The glass and DLC film roughness were measured using non destructive methods, such as a high step meter, Atomic Force Microscopy and Diffuse Reflectance. Other properties, such as refractive index of both materials were measured. The DOEs were tested using 632.8 nm HeNe laser.

  7. Synthesis and characterization of azo-containing organometallic thin films for all optical switching applications

    Science.gov (United States)

    Gatri, R.; Fillaut, J.-L.; Mysliwiec, J.; Szukalski, A.; Bartkiewicz, S.; El-Ouazzani, H.; Guezguez, I.; Khammar, F.; Sahraoui, B.

    2012-05-01

    Novel photoresponsive materials based on azo-containing bifunctional ruthenium-acetylides have been synthesized. All optical switching based on the Optical Kerr Effect in the organometallic thin films based on ruthenium(II) acetylides containing an azobenzene moiety as a photochromic unit in the main pi-conjugated system dispersed in a poly(methyl methacrylate) matrix has been observed. The excitation beam was delivered from a picosecond laser at wavelength 532 nm while dynamics of induced sample birefringence was probed by a non-absorbed linearly polarized beam of cw He-Ne laser (632.8 nm). The influence of ruthenium part on dynamics of molecular motions has been shown.

  8. All-optical subdiffraction multilevel data encoding onto azo-polymeric thin films

    Science.gov (United States)

    Savoini, Matteo; Biagioni, Paolo; Duò, Lamberto; Finazzi, Marco

    2009-03-01

    By exploiting photo-induced reorientation in azo-polymer thin films, we demonstrate all-optical polarization-encoded information storage with a scanning near-field optical microscope. In the writing routine, 5-level bits are created by associating different bit values to different birefringence directions, induced in the polymer after illumination with linearly polarized light. The reading routine is then performed by implementing polarization-modulation techniques on the same near-field microscope, in order to measure the encoded birefringence direction.

  9. Structural and optical properties of electron beam evaporated yttria stabilized zirconia thin films

    Energy Technology Data Exchange (ETDEWEB)

    Kirubaharan, A. Kamalan; Kuppusami, P., E-mail: pkigcar@gmail.com; Dharini, T.; Ramachandran, D. [Centre for Nanoscience and Nanotechnology, Sathyabama University, Chennai-600119 (India); Singh, Akash; Mohandas, E. [Physical Metallurgy Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)

    2015-06-24

    Yttria stabilized zirconia (10 mole % Y{sub 2}O{sub 3}) thin films were deposited on quartz substrates using electron beam physical vapor deposition at the substrate temperatures in the range 300 – 973 K. XRD analysis showed cubic crystalline phase of YSZ films with preferred orientation along (111). The surface roughness was found to increase with the increase of deposition temperatures. The optical band gap of ∼5.7 eV was calculated from transmittance curves. The variation in the optical properties is correlated with the changes in the microstructural features of the films prepared as a function of substrate temperature.

  10. Optical Characterization of Organic Light-Emitting Thin Films in the Ultraviolet and Visible Spectral Ranges

    CERN Document Server

    Montereali, R M; Nichelatti, E; Di Pompeo, F; Segreto, E; Canci, N; Cavanna, F

    2012-01-01

    The spectrophotometric characterization of high efficiency, optically-active samples such as light-emitting organic bulks and thin films can be problematic because their broad-band luminescence is detected together with the monochromatic transmitted and reflected signals, hence perturbing measurements of optical transmittance and reflectance at wavelengths within the photoexcitation band. As a matter of fact, most commercial spectrophotometers apply spectral filtering before the light beam reaches the sample, not after it. In this Report, we introduce and discuss the method we have developed to correct photometric spectra that are perturbed by photoluminescence.

  11. Light irradiation tuning of surface wettability, optical, and electric properties of graphene oxide thin films

    Science.gov (United States)

    Furio, A.; Landi, G.; Altavilla, C.; Sofia, D.; Iannace, S.; Sorrentino, A.; Neitzert, H. C.

    2017-02-01

    In this work the preparation of flexible polymeric films with controlled electrical conductivity, light transmission and surface wettability is reported. A drop casted graphene oxide thin film is photo-reduced at different levels by UV light or laser irradiation. Optical microscopy, IR spectroscopy, electrical characterization, Raman spectroscopy and static water contact angle measurements are used in order to characterize the effects of the various reduction methods. Correlations between the optical, electrical and structural properties are reported and compared to previous literature results. These correlations provide a useful tool for independently tuning the properties of these films for specific applications.

  12. Ferroelectric BaTiO3 thin-film optical waveguide modulators

    OpenAIRE

    Petraru, A.; Schubert, J; Schmid, M.; Buchal, Ch.

    2002-01-01

    High-quality BaTiO3 epitaxial thin films on MgO substrates have been grown by pulsed-laser deposition. Both, c-axis and a-axis BaTiO3 orientations were studied. Mach-Zehnder optical waveguide modulators with a fork angle of 1.7degrees have been fabricated by ion-beam etching. The waveguides are of the ridge type, the BaTiO3 thickness is 1 mum, the ridge step 50 nm, and the width 2 mum. Light was coupled into the waveguides from optical fibers. The BaTiO3 waveguide propagation losses are 2-3 d...

  13. Optical band gap of Sn0.2Bi1.8Te3 thin films

    Indian Academy of Sciences (India)

    P H Soni; M V Hathi; C F Desai

    2003-12-01

    Sn0.2Bi1.8Te3 thin films were grown using the thermal evaporation technique on a (001) face of NaCl crystal as a substrate at room temperature. The optical absorption was measured in the wave number range 500–4000 cm-1. From the optical absorption data the band gap was evaluated and studied as a function of film thickness and deposition temperature. The data indicate absorption through direct interband transition with a band gap of around 0.216 eV. The detailed results are reported here.

  14. Size dependent optical characteristics of chemically deposited nanostructured ZnS thin films

    Indian Academy of Sciences (India)

    A U Ubale; V S Sangawar; D K Kulkarni

    2007-04-01

    ZnS thin films of different thicknesses were prepared by chemical bath deposition using thiourea and zinc acetate as S2- and Zn2+ source. The effect of film thickness on the optical and structural properties was studied. The optical absorption studies in the wavelength range 250–750 nm show that band gap energy of ZnS increases from 3.68–4.10 eV as thickness varied from 332–76 nm. The structural estimation shows variation in grain size from 6.9–17.8 nm with thickness. The thermoemf measurement indicates that films prepared by this method are of -type.

  15. OPTICAL BAND GAP AND CONDUCTIVITY MEASUREMENTS OF POLYPYRROLE-CHITOSAN COMPOSITE THIN FILMS

    Institute of Scientific and Technical Information of China (English)

    Mahnaz M.Abdi; H.N.M.Ekramul Mahmud; Luqman Chuah Abdullah; Anuar Kassim; Mohamad Zaki Ab.Rahman; Josephine Liew Ying Chyi

    2012-01-01

    Electrical conductivity and optical properties of polypyrrole-chitosan (PPy-CHI) conducting polymer composites have been investigated to determine the optical transition characteristics and energy band gap of composite films.The two electrode method and Ⅰ-Ⅴ characteristic technique were used to measure the conductivity of the PPy-CHI thin films,and the optical band gap was obtained from their ultraviolet absorption edges.Depending upon experimental parameter,the optical band gap (Eg) was found within 1.30-2.32 eV as estimated from optical absorption data.The band gap of the composite films decreased as the CHI content increased.The room temperature electrical conductivity of PPy-CHI thin films was found in the range of 5.84 × 10-7-15.25 × 10-7 S.cm-1 depending on the chitosan content.The thermogravimetry analysis (TGA)showed that the CHI can improve the thermal stability of PPy-CHI composite films.

  16. Dispersion model for optical thin films applicable in wide spectral range

    Science.gov (United States)

    Franta, Daniel; Nečas, David; Ohlídal, Ivan; Giglia, Angelo

    2015-09-01

    In the optics industry thin film systems are used to construct various interference devices such as antireflective coatings, high-reflectance mirrors, beam splitters and filters. The optical characterization of complex optical systems can not be performed by measurements only in the short spectral range in which the interference devices will be employed because the measured data do not contain sufficient information about all relevant parameters of these systems. The characterization of film materials requires the extension of the spectral range of the measurements to the IR region containing phonon absorption and to the UV region containing the electronic excitations. However, this leads to necessity of a dispersion model suitable for the description of the dielectric response in the wide spectral range. Such model must respect the physical conditions following from theory of dispersion, particularly Kramers-Kronig relations and integrability imposed by sum rules. This work presents the construction of a universal dispersion model composed from individual contributions representing both electronic and phonon excitations. The efficiency of presented model is given by the fact that all the contributions are described by analytical expressions. It is shown that the model is suitable for precise modeling of spectral dependencies of optical constants of a broad class of materials used in the optical industry for thin film systems such as MgF2, SiO2, Al2O3, HfO2, Ta2O5 and TiO2 in the spectral range from far IR to vacuum UV.

  17. Structural, electrical, and optical properties of ZnInO alloy thin films

    Institute of Scientific and Technical Information of China (English)

    Cai Xi-Kun; Yuan Zi-Jian; Zhu Xia-Ming; Wang Xiong; Zhang Bing-Po; Qiu Dong-Jiang; Wu Hui-Zhen

    2011-01-01

    Indium zinc oxide (IZO) thin films with different percentages of In content (In/[In+Zn]) are synthesized on glass substrates by magnetron sputtering,and the structural,electrical and optical properties of IZO thin films deposited at different In2O3 target powers are investigated.IZO thin films grown at different In2O3 target sputtering powers show evident morphological variation and different grain sizes.As the In2O3 sputtering power rises,the grain size becomes larger and electrical mobility increases.The film grown with an In2O3 target power of 100 W displays the highest electrical mobility of 13.5 cm.V-1s-1 and the lowest resistivity of 2.4× 10-3 Ω·cm.The average optical transmittance of the IZO thin film in the visible region reaches 80% and the band gap broadens with the increase of In2O3 target power,which is attributed to the increase in carrier concentration and is in accordance with Burstein-Moss shift theory.

  18. Optical and electrical properties of TiOPc doped Alq3 thin films

    Science.gov (United States)

    Ramar, M.; Suman, C. K.; Tyagi, Priyanka; Srivastava, R.

    2015-06-01

    The Titanyl phthalocyanine (TiOPc) was doped in Tris (8-hydroxyquinolinato) aluminum (Alq3) with different concentration. The thin film of optimized doping concentration was studied extensively for optical and electrical properties. The optical properties, studied using ellipsometry, absorption and photoluminescence. The absorption peak of Alq3 and TiOPc was observed at 387 nm and 707 nm and the photo-luminescence intensity (PL) peak of doped thin film was observed at 517 nm. The DC and AC electrical properties of the thin film were studied by current density-voltage (J-V) characteristics and impedance over a frequency range of 100 Hz - 1 MHz. The electron mobility calculated from trap-free space-charge limited region (SCLC) is 0.17×10-5 cm2/Vs. The Cole-Cole plots shows that the TiOPc doped Alq3 thin film can be represented by a single parallel resistance RP and capacitance CP network with a series resistance RS (10 Ω). The value of RP and CP at zero bias was 1587 Ω and 2.568 nF respectively. The resistance RP decreases with applied bias whereas the capacitance CP remains almost constant.

  19. Optical and electrical properties of TiOPc doped Alq{sub 3} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Ramar, M.; Suman, C. K., E-mail: sumanck@nplindia.org; Tyagi, Priyanka; Srivastava, R. [CSIR-Network of Institutes for Solar Energy CSIR - National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi -110012 (India)

    2015-06-24

    The Titanyl phthalocyanine (TiOPc) was doped in Tris (8-hydroxyquinolinato) aluminum (Alq3) with different concentration. The thin film of optimized doping concentration was studied extensively for optical and electrical properties. The optical properties, studied using ellipsometry, absorption and photoluminescence. The absorption peak of Alq{sub 3} and TiOPc was observed at 387 nm and 707 nm and the photo-luminescence intensity (PL) peak of doped thin film was observed at 517 nm. The DC and AC electrical properties of the thin film were studied by current density-voltage (J-V) characteristics and impedance over a frequency range of 100 Hz - 1 MHz. The electron mobility calculated from trap-free space-charge limited region (SCLC) is 0.17×10{sup −5} cm{sup 2}/Vs. The Cole-Cole plots shows that the TiOPc doped Alq{sub 3} thin film can be represented by a single parallel resistance R{sub P} and capacitance C{sub P} network with a series resistance R{sub S} (10 Ω). The value of R{sub P} and C{sub P} at zero bias was 1587 Ω and 2.568 nF respectively. The resistance R{sub P} decreases with applied bias whereas the capacitance C{sub P} remains almost constant.

  20. Nonlinear Optical Properties of Indium Phthalocyanine Axially Grafted Polystyrene Thin Film

    Institute of Scientific and Technical Information of China (English)

    ZHU Rong-Yi; QIU Xue-Qiong; CHEN Yu; QIAN Shi-Xiong

    2006-01-01

    @@ Ultrafast dynamics and third-order nonlinearity of thin films of tert-butyl peripherally-substituted indium ph thalocyanine axially grafted polystyrene (tBu4PcIn-PS) are investigated by femtosecond optical-Kerr-effect (OKE) and z-scan experiments. The fastest component (< 200 fs) in the OKE traces of the film is related to the electron cloud distortion, where the phthalocyanine-polymer interaction may enhance this contribution.

  1. Multimode distributed feedback laser emission in a dye-doped optically pumped polymer thin-film

    Science.gov (United States)

    Sobel, F.; Gindre, D.; Nunzi, J.-M.; Denis, C.; Dumarcher, V.; Fiorini-Debuisschert, C.; Kretsch, K. P.; Rocha, L.

    2004-11-01

    We report on particular features of thin film distributed feedback (DFB) lasers. Devices are optically pumped using a Lloyd-mirror interferometer. For a given DFB grating period, the number of lasing modes is film thickness dependent. Spectral content of the devices is analysed using planar waveguide theory. An excellent agreement between the theoretical transverse electric mode structure and the laser emission spectrum is found.

  2. Effects of Alloying on the Optical Properties of Organic-Inorganic Lead Halide Perovskite Thin Films

    Energy Technology Data Exchange (ETDEWEB)

    Ndione, Paul F.; Li, Zhen; Zhu, Kai

    2016-09-07

    Complex refractive index and dielectric function spectra of organic-inorganic lead halide perovskite alloy thin films are presented, together with the critical-point parameter analysis (energy and broadening) of the respective composition. Thin films of methylammonium lead halide alloys (MAPbI3, MAPbBr3, MAPbBr2I, and MAPbBrI2), formamidinium lead halide alloys (FAPbI3, FAPbBr3, and FAPbBr2I), and formamidinium cesium lead halide alloys [FA0.85Cs0.15PbI3, FA0.85Cs0.15PbBrI2, and FA0.85Cs0.15Pb(Br0.4I0.6)3] were studied. The complex refractive index and dielectric functions were determined by spectroscopic ellipsometry (SE) in the photon energy range of 0.7-6.5 eV. Critical point energies and optical transitions were obtained by lineshape fitting to the second-derivative of the complex dielectric function data of these thin films as a function of alloy composition. Absorption onset in the vicinity of the bandgap, as well as critical point energies and optical band transition shift toward higher energies as the concentration of Br in the films increases. Cation alloying (Cs+) has less effect on the optical properties of the thin films compared to halide mixed alloys. The reported optical properties can help to understand the fundamental properties of the perovskite materials and also be used for optimizing or designing new devices.

  3. Optical Properties and Characterization of Prepared Sn-Doped PbSe Thin Film

    Directory of Open Access Journals (Sweden)

    M. R. Khanlary

    2012-01-01

    Full Text Available Physical vapor deposition of tin-doped lead selenide (Sn/PbSe thin films on SiO2 glass is described. Interaction of high-energy Ar+ ions bombardment on the doped PbSe films is discussed by XRD analysis. The improvement of optical band gap of Sn/PbSe films irradiated by different doses of irradiation was studied using transmission spectroscopy.

  4. Synthesis and Characterization of High c-axis ZnO Thin Film by Plasma Enhanced Chemical Vapor Deposition System and its UV Photodetector Application.

    Science.gov (United States)

    Chao, Chung-Hua; Wei, Da-Hua

    2015-10-03

    In this study, zinc oxide (ZnO) thin films with high c-axis (0002) preferential orientation have been successfully and effectively synthesized onto silicon (Si) substrates via different synthesized temperatures by using plasma enhanced chemical vapor deposition (PECVD) system. The effects of different synthesized temperatures on the crystal structure, surface morphologies and optical properties have been investigated. The X-ray diffraction (XRD) patterns indicated that the intensity of (0002) diffraction peak became stronger with increasing synthesized temperature until 400 (o)C. The diffraction intensity of (0002) peak gradually became weaker accompanying with appearance of (10-10) diffraction peak as the synthesized temperature up to excess of 400 (o)C. The RT photoluminescence (PL) spectra exhibited a strong near-band-edge (NBE) emission observed at around 375 nm and a negligible deep-level (DL) emission located at around 575 nm under high c-axis ZnO thin films. Field emission scanning electron microscopy (FE-SEM) images revealed the homogeneous surface and with small grain size distribution. The ZnO thin films have also been synthesized onto glass substrates under the same parameters for measuring the transmittance. For the purpose of ultraviolet (UV) photodetector application, the interdigitated platinum (Pt) thin film (thickness ~100 nm) fabricated via conventional optical lithography process and radio frequency (RF) magnetron sputtering. In order to reach Ohmic contact, the device was annealed in argon circumstances at 450 (o)C by rapid thermal annealing (RTA) system for 10 min. After the systematic measurements, the current-voltage (I-V) curve of photo and dark current and time-dependent photocurrent response results exhibited a good responsivity and reliability, indicating that the high c-axis ZnO thin film is a suitable sensing layer for UV photodetector application.

  5. Reversible tuning of ZnO optical band gap by plasma treatment

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Szetsen, E-mail: slee@cycu.edu.tw [Department of Chemistry and Center for Nano-technology, Chung Yuan Christian University, Jhongli, Taoyuan 32023, Taiwan (China); Peng, Jr-Wei [Department of Chemistry and Center for Nano-technology, Chung Yuan Christian University, Jhongli, Taoyuan 32023, Taiwan (China); Ho, Ching-Yuan [Department of Mechanical Engineering, Chung Yuan Christian University, Jhongli, Taoyuan 32023, Taiwan (China)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer The ZnO optical band gap blue-shifts with hydrogen plasma treatment. Black-Right-Pointing-Pointer The ZnO optical band gap red-shifts with oxygen plasma treatment. Black-Right-Pointing-Pointer The ZnO optical band gap can be reversibly fine-tuned. - Abstract: Zinc oxide (ZnO) films synthesized by reacting zinc nitrate with hexamethylenetetramine were treated with hydrogen and oxygen plasmas. From UV-visible absorption and optical emission inspection, we have found that the optical band gap of ZnO films blue-shifted with hydrogen plasma treatment, but red-shifted with oxygen plasma treatment. By alternating the treatment sequence of hydrogen and oxygen plasmas, the ZnO optical band gap can be reversibly fine-tuned with the tunable range up to 80 meV. Scanning electron microscopy characterization indicates that the variation of the optical band gap is attributed to the competition between amorphous and crystalline forms of ZnO. The mechanism of reversible optical band gap tuning is discussed.

  6. Optical and thermal properties of azo derivatives of salicylic acid thin films

    Science.gov (United States)

    Ghoneim, M. M.; El-Ghamaz, N. A.; El-Sonbati, A. Z.; Diab, M. A.; El-Bindary, A. A.; Serag, L. S.

    2015-02-01

    N-acryloyl-4-aminosalicylic acid (4-AMSA), monomer (HL) and 5-(4‧-alkyl phenylazo)-N-acryloyl-4-aminosalicylic acid (HLn) are synthesized and characterized with various physico-chemical techniques. Thin films of 5-(4‧-alkyl phenylazo)-N-acryloyl-4-aminosalicylic acid (HLn) are prepared by spin coating technique. The X-ray diffraction (XRD) patterns of 4-aminosalicylic acid (4-ASA) and its derivatives are investigated in powder and thin film forms. Thermal properties of the compounds are investigated by thermogravemetric analysis (TGA). The optical energy gap and the type of optical transition are investigated in the wavelength range (200-2500 nm) for 4-ASA, HL and HLn. The values of fundamental energy gap (Eg) are in the range 3.60-3.69 eV for all compounds and the type of optical transition is found to be indirect allowed. The onset energy gap Eg∗ appeared only for azodye compounds is found to be in the range 0.95-1.55 eV depending on the substituent function groups. The refractive index, n, shows a normal dispersion in the wavelength range 650-2500 nm, while shows anomalous dispersion in the wavelength rang 200-650 nm. The dispersion parameters ε∞, εL, Ed, Eo and N /m∗ are calculated. The photoluminescence phenomena (PL) appear for thin films of 4-ASA and its derivatives show three main emission transitions.

  7. Studies on the Optical Properties and Surface Morphology of Cobalt Phthalocyanine Thin Films

    Directory of Open Access Journals (Sweden)

    Benny Joseph

    2008-01-01

    Full Text Available Thin films of Cobalt Phthalocyanine (CoPc are fabricated at a base pressure of 10-5 m.bar using Hind-Hivac thermal evaporation plant. The films are deposited on to glass substrates at various temperatures 318, 363, 408 and 458K. The optical absorption spectra of these thin films are measured. The present studies reveal that the optical band gap energies of CoPc thin films are almost same on substrate temperature variation. The structure and surface morphology of the films deposited on glass substrates of temperatures 303, 363 and 458K are studied using X-ray diffractograms and Scanning Electron Micrographs (SEM, which show that there is a change in the crystallinity and surface morphology due to change in the substrate temperatures. Full width at half maximum (FWHM intensity of the diffraction peaks is also found reduced with increasing substrate temperatures. Scanning electron micrographs show that these crystals are needle like, which are interconnected at high substrate temperatures. The optical band gap energy is almost same on substrate temperature variation. Trap energy levels are also observed for these films.

  8. Optical properties of silver sulphide thin films formed on evaporated Ag by a simple sulphurization method

    Energy Technology Data Exchange (ETDEWEB)

    Barrera-Calva, E., E-mail: ebc@xanum.uam.m [Departamento de Ingenieria de Procesos e hidraulica, Universidad Autonoma Metropolitana - Iztapalapa, Av. Purisima Esq. Michoacan, Col. Vicentina, Mexico, D.F., 09340 (Mexico); Ortega-Lopez, M.; Avila-Garcia, A.; Matsumoto-Kwabara, Y. [Departamento de Ingenieria Electrica, Centro de Investigacion y de Estudios Avanzados del IPN, Mexico DF 07360 (Mexico)

    2010-01-31

    Silver sulphide (Ag{sub 2}S) thin films were grown on the surface of silver films (Ag) deposited on glass substrate by using a simple chemical sulphurization method. According to X-ray diffraction analysis, the Ag{sub 2}S thin films display low intensity peaks at 34.48{sup o}, 36.56{sup o}, and 44.28{sup o}, corresponding to diffraction from (100), (112) and (103) planes of the acanthite phase (monoclinic). A model of the type Ag{sub 2}S/Ag/glass was deduced from spectroscopic ellipsometric measurements. Also, the optical constants (n, k) of the system were determined. Furthermore, the optical properties as solar selective absorber for collector applications were assessed. The optical reflectance of the Ag{sub 2}S/Ag thin film systems exhibits the expected behavior for an ideal selective absorber, showing a low reflectance in the wavelength range below 2 {mu}m and a high reflectance for wavelengths higher than that value. An absorptance about 70% and an emittance about 3% or less were calculated for several samples.

  9. Structural, Optical and Electrical Properties of NiO Nanostructure Thin Film

    Directory of Open Access Journals (Sweden)

    M. Ghougali

    2016-12-01

    Full Text Available Nickel oxide was deposited on highly cleaned glass substrates using spray pneumatic technique. The effect of precursor molarity on structural, optical and electrical properties has been studied. The XRD lines of the deposited NiO were enhanced with increasing precursor molarity due to the improvement of the films crystallinity. It was shown that the crystalline size of the deposited thin films was calculated using Debye-Scherer formula and found in the range between 9 and 47 nm. The optical properties have been discussed in this work. The absorbance (A, the transmittance (T and the reflectance (R were measured and calculated. Band gap energy is considered one of the most important optical parameter, therefore measured and found ranging between 3.64 and 3.86 eV. The NiO thin film reduces the light reflection for visible range light. The increase of the electrical conductivity to maximum value of 0.0896 (Ω cm – 1 can be explained by the increase in carrier concentration of the films. A good electrical conductivity of the NiO thin film is obtained due to the electrically low sheet resistance. NiO can be applied in different electronic and optoelectronic applications due to its high band gap, high transparency and good electrical conductivity.

  10. Studies on the Optical Properties and Surface Morphology of Nickel Phthalocyanine Thin Films

    Directory of Open Access Journals (Sweden)

    Benny Joseph

    2007-01-01

    Full Text Available Thin films of Nickel Phthalocyanine (NiPc are fabricated at a base pressure of 10-5 m.bar using Hind-Hivac thermal evaporation plant. The films are deposited on to glass substrates at various temperatures 318, 363, 408 and 458K. The optical absorption spectra of these thin films are measured. Present studies reveal that the optical band gap energies of NiPc thin films are highly dependent on the substrate temperatures. The structure and surface morphology of the films deposited on glass substrates of temperatures 303, 363 and 458K are studied using X-ray diffractograms and Scanning Electron Micrographs (SEM, show that there is a change in the crystallinity and surface morphology due to change in the substrate temperatures. Full width at half maximum (FWHM intensity of the diffraction peaks is also found reduced with increasing substrate temperatures. Scanning electron micrographs show that these crystals are fiber like at high substrate temperatures. The optical band gap increases with increase in substrate temperature and is then reduced with fiber-like grains at 408K. The band gap increases again at 458K with full of fiber like grains. Trap energy levels are also observed for these films.

  11. Preparation, structural and optical characterization of nanocrystalline CdS thin film

    Science.gov (United States)

    Abdel-Galil, A.; Balboul, M. R.; Atta, A.; Yahia, I. S.; Sharaf, A.

    2014-08-01

    Nano-structured CdS thin film was deposited onto a glass substrate by an electron beam evaporation technique at room temperature from a powder prepared by a hydrothermal method. The morphology and structural properties of the as-deposited film were characterized using atomic force microscopy (AFM) and X-ray diffraction (XRD) techniques. The AFM morphology study confirms that the CdS thin film has nano-sized grains and a dense morphology. The mean particle size that resulted from XRD analyses was 8.4 nm. Also, the XRD patterns show that CdS powder and thin film have hexagonal wurtzite type structure with a preferred c-axis orientation along (002) plane. The refractive index and the film thickness were obtained using the Swanepoel method from transmission spectrum. The optical band gap was calculated from the absorption spectrum, and was found to be 2.41 eV corresponding to direct optical transition. The dispersion of the refractive index was explained using a single oscillator model. The dielectric relaxation time and the optical conductivity were determined and studied with photon energy.

  12. Electrical and Optical Properties of GeSi−:H Thin Films Prepared by Thermal Evaporation Method

    Directory of Open Access Journals (Sweden)

    A. A. J. Al-Douri

    2010-01-01

    Full Text Available Thin a-GeSi1−:H films were grown successfully by fabrication of designated ingot followed by evaporation onto glass slides. A range of growth conditions, Ge contents, dopant concentration (Al and As, and substrate temperature, were employed. Stoichiometry of the thin films composition was confirmed using standard surface techniques. The structure of all films was amorphous. Film composition and deposition parameters were investigated for their bearing on film electrical and optical properties. More than one transport mechanism is indicated. It was observed that increasing substrate temperature, Ge contents, and dopant concentration lead to a decrease in the optical energy gap of those films. The role of the deposition conditions on values of the optical constants was determined. Accordingly, models of the density of states for the Ge0.5Si0.5:H thin films as pure, doped with 3.5% of Al (p-type and that doped with 3.5% As (n-type, were proposed.

  13. Electrical and Optical Properties of Fluorine Doped Tin Oxide Thin Films Prepared by Magnetron Sputtering

    Directory of Open Access Journals (Sweden)

    Ziad Y. Banyamin

    2014-10-01

    Full Text Available Fluorine doped tin oxide (FTO coatings have been prepared using the mid-frequency pulsed DC closed field unbalanced magnetron sputtering technique in an Ar/O2 atmosphere using blends of tin oxide and tin fluoride powder formed into targets. FTO coatings were deposited with a thickness of 400 nm on glass substrates. No post-deposition annealing treatments were carried out. The effects of the chemical composition on the structural (phase, grain size, optical (transmission, optical band-gap and electrical (resistivity, charge carrier, mobility properties of the thin films were investigated. Depositing FTO by magnetron sputtering is an environmentally friendly technique and the use of loosely packed blended powder targets gives an efficient means of screening candidate compositions, which also provides a low cost operation. The best film characteristics were achieved using a mass ratio of 12% SnF2 to 88% SnO2 in the target. The thin film produced was polycrystalline with a tetragonal crystal structure. The optimized conditions resulted in a thin film with average visible transmittance of 83% and optical band-gap of 3.80 eV, resistivity of 6.71 × 10−3 Ω·cm, a carrier concentration (Nd of 1.46 × 1020 cm−3 and a mobility of 15 cm2/Vs.

  14. Practice-oriented optical thin film growth simulation via multiple scale approach

    Energy Technology Data Exchange (ETDEWEB)

    Turowski, Marcus, E-mail: m.turowski@lzh.de [Laser Zentrum Hannover e.V., Hollerithallee 8, Hannover 30419 (Germany); Jupé, Marco [Laser Zentrum Hannover e.V., Hollerithallee 8, Hannover 30419 (Germany); QUEST: Centre of Quantum Engineering and Space-Time Research, Leibniz Universität Hannover (Germany); Melzig, Thomas [Fraunhofer Institute for Surface Engineering and Thin Films IST, Bienroder Weg 54e, Braunschweig 30108 (Germany); Moskovkin, Pavel [Research Centre for Physics of Matter and Radiation (PMR-LARN), University of Namur (FUNDP), 61 rue de Bruxelles, Namur 5000 (Belgium); Daniel, Alain [Centre for Research in Metallurgy, CRM, 21 Avenue du bois Saint Jean, Liège 4000 (Belgium); Pflug, Andreas [Fraunhofer Institute for Surface Engineering and Thin Films IST, Bienroder Weg 54e, Braunschweig 30108 (Germany); Lucas, Stéphane [Research Centre for Physics of Matter and Radiation (PMR-LARN), University of Namur (FUNDP), 61 rue de Bruxelles, Namur 5000 (Belgium); Ristau, Detlev [Laser Zentrum Hannover e.V., Hollerithallee 8, Hannover 30419 (Germany); QUEST: Centre of Quantum Engineering and Space-Time Research, Leibniz Universität Hannover (Germany)

    2015-10-01

    Simulation of the coating process is a very promising approach for the understanding of thin film formation. Nevertheless, this complex matter cannot be covered by a single simulation technique. To consider all mechanisms and processes influencing the optical properties of the growing thin films, various common theoretical methods have been combined to a multi-scale model approach. The simulation techniques have been selected in order to describe all processes in the coating chamber, especially the various mechanisms of thin film growth, and to enable the analysis of the resulting structural as well as optical and electronic layer properties. All methods are merged with adapted communication interfaces to achieve optimum compatibility of the different approaches and to generate physically meaningful results. The present contribution offers an approach for the full simulation of an Ion Beam Sputtering (IBS) coating process combining direct simulation Monte Carlo, classical molecular dynamics, kinetic Monte Carlo, and density functional theory. The simulation is performed exemplary for an existing IBS-coating plant to achieve a validation of the developed multi-scale approach. Finally, the modeled results are compared to experimental data. - Highlights: • A model approach for simulating an Ion Beam Sputtering (IBS) process is presented. • In order to combine the different techniques, optimized interfaces are developed. • The transport of atomic species in the coating chamber is calculated. • We modeled structural and optical film properties based on simulated IBS parameter. • The modeled and the experimental refractive index data fit very well.

  15. Application of femtosecond laser ablation inductively coupled plasma mass spectrometry for quantitative analysis of thin Cu(In,Ga)Se{sub 2} solar cell films

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seokhee [School of Mechatronics, Gwangju Institute of Science and Technology, 1 Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of); Gonzalez, Jhanis J. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Applied Spectra Inc., 46665 Fremont Boulevard, Fremont, CA 94538 (United States); Yoo, Jong H. [Applied Spectra Inc., 46665 Fremont Boulevard, Fremont, CA 94538 (United States); Chirinos, Jose R. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Facultad de Ciencias, Universidad Central de Venezuela, Caracas 1041A (Venezuela, Bolivarian Republic of); Russo, Richard E. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Applied Spectra Inc., 46665 Fremont Boulevard, Fremont, CA 94538 (United States); Jeong, Sungho, E-mail: shjeong@gist.ac.kr [School of Mechatronics, Gwangju Institute of Science and Technology, 1 Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of)

    2015-02-27

    This work reports that the composition of Cu(In,Ga)Se{sub 2} (CIGS) thin solar cell films can be quantitatively predicted with high accuracy and precision by femtosecond laser ablation-inductively coupled plasma-mass spectrometry (fs-LA-ICP-MS). It is demonstrated that the results are strongly influenced by sampling conditions during fs-laser beam (λ = 1030 nm, τ = 450 fs) scanning on the CIGS surface. The fs-LA-ICP-MS signals measured at optimal sampling conditions generally provide a straight line calibration with respect to the reference concentrations measured by inductively coupled plasma optical emission spectroscopy (ICP-OES). The concentration ratios predicted by fs-LA-ICP-MS showed high accuracy, to 95–97% of the values measured with ICP-OES, for Cu, In, Ga, and Se elements. - Highlights: • Laser ablation inductively coupled plasma mass spectrometry of thin film is reported. • Concentration ratio prediction with a confidence level of 95–97% is achieved. • Quantitative determination of composition is demonstrated.

  16. Synthesis of thin films in boron-carbon-nitrogen ternary system by microwave plasma enhanced chemical vapor deposition

    Science.gov (United States)

    Kukreja, Ratandeep Singh

    The Boron Carbon Nitorgen (B-C-N) ternary system includes materials with exceptional properties such as wide band gap, excellent thermal conductivity, high bulk modulus, extreme hardness and transparency in the optical and UV range that find application in most fields ranging from micro-electronics, bio-sensors, and cutting tools to materials for space age technology. Interesting materials that belong to the B-C-N ternary system include Carbon nano-tubes, Boron Carbide, Boron Carbon Nitride (B-CN), hexagonal Boron Nitride ( h-BN), cubic Boron Nitride (c-BN), Diamond and beta Carbon Nitride (beta-C3N4). Synthesis of these materials requires precisely controlled and energetically favorable conditions. Chemical vapor deposition is widely used technique for deposition of thin films of ceramics, metals and metal-organic compounds. Microwave plasma enhanced chemical vapor deposition (MPECVD) is especially interesting because of its ability to deposit materials that are meta-stable under the deposition conditions, for e.g. diamond. In the present study, attempt has been made to synthesize beta-carbon nitride (beta-C3N4) and cubic-Boron Nitride (c-BN) thin films by MPECVD. Also included is the investigation of dependence of residual stress and thermal conductivity of the diamond thin films, deposited by MPECVD, on substrate pre-treatment and deposition temperature. Si incorporated CNx thin films are synthesized and characterized while attempting to deposit beta-C3N4 thin films on Si substrates using Methane (CH4), Nitrogen (N2), and Hydrogen (H2). It is shown that the composition and morphology of Si incorporated CNx thin film can be tailored by controlling the sequence of introduction of the precursor gases in the plasma chamber. Greater than 100mum size hexagonal crystals of N-Si-C are deposited when Nitrogen precursor is introduced first while agglomerates of nano-meter range graphitic needles of C-Si-N are deposited when Carbon precursor is introduced first in the

  17. Optical constants of CH3NH3PbBr3 perovskite thin films measured by spectroscopic ellipsometry

    KAUST Repository

    Alias, Mohd Sharizal

    2016-07-14

    The lack of optical constants information for hybrid perovskite of CH3NH3PbBr3 in thin films form can delay the progress of efficient LED or laser demonstration. Here, we report on the optical constants (complex refractive index and dielectric function) of CH3NH3PbBr3 perovskite thin films using spectroscopic ellipsometry. Due to the existence of voids, the refractive index of the thin films is around 8% less than the single crystals counterpart. The energy bandgap is around 2.309 eV as obtained from photoluminescence and spectrophotometry spectra, and calculated from the SE analysis. The precise measurement of optical constants will be useful in designing optical devices using CH3NH3PbBr3 thin films.

  18. Nonlinear interaction of ultraintense laser pulse with relativistic thin plasma foil in the radiation pressure-dominant regime

    Indian Academy of Sciences (India)

    KRISHNA KUMAR SONI; K P MAHESHWARI

    2016-11-01

    We present a study of the effect of laser pulse temporal profile on the energy/momentum acquired by the ions as a result of the ultraintense laser pulse focussed on a thin plasma layer in the radiation pressuredominant(RPD) regime. In the RPD regime, the plasma foil is pushed by ultraintense laser pulse when the radiation cannot propagate through the foil, while the electron and ion layers move together. The nonlinear character of laser–matter interaction is exhibited in the relativistic frequency shift, and also change in the wave amplitude as the EM wave gets reflected by the relativistically moving thin dense plasma layer. Relativistic effects in a highenergy plasma provide matching conditions that make it possible to exchange very effectively ordered kineticenergy and momentum between the EM fields and the plasma. When matter moves at relativistic velocities, the efficiency of the energy transfer from the radiation to thin plasma foil is more than 30% and in ultrarelativisticcase it approaches one. The momentum/energy transfer to the ions is found to depend on the temporal profile of the laser pulse. Our numerical results show that for the same laser and plasma parameters, a Lorentzian pulse canaccelerate ions upto 0.2 GeV within 10 fs which is 1.5 times larger than that a Gaussian pulse can.

  19. Structural, optical, photoluminescence, dielectric and electrical studies of vacuum-evaporated CdTe thin films

    Indian Academy of Sciences (India)

    Ziaul Raza Khan; M Zulfequar; Mohd Shahid Khan

    2012-04-01

    Highly-oriented CdTe thin films were fabricated on quartz and glass substrates by thermal evaporation technique in the vacuum of about 2 × 10-5 torr. The CdTe thin films were characterized by X-ray diffraction (XRD), UV–VIS–NIR, photoluminescence spectroscopy and scanning electron microscopy (SEM). X-ray diffraction results showed that the films were polycrystalline with cubic structure and had preferred growth of grains along the (111) crystallographic direction. Scanning electron micrographs showed that the growth of crystallites of comparable size on both the substrates. At the room temperature, photoluminescence spectra of the films on both the substrates showed sharp peaks with a maximum at 805 nm. This band showed significant narrowing suggesting that it originates from the transitions involving grain boundary defects. The refractive index of CdTe thin films was calculated using interference pattern of transmission spectra. The optical band gap of thin films was found to allow direct transition with energy gap of 1.47–1.50 eV. a.c. conductivity of CdTe thin films was found to increase with the increase in frequency whereas dielectric constant was observed to decrease with the increase in frequency.

  20. Linear and nonlinear optical discussions of nanostructured Zn-doped CdO thin films

    Science.gov (United States)

    Yahia, I. S.; Salem, G. F.; Iqbal, Javed; Yakuphanoglu, F.

    2017-04-01

    Here, we report the doping effect of zinc (Zn) on the physical properties of cadmium oxide (CdO) at various concentrations (1, 2, 3 and 4 wt% of Zn). The studied samples were prepared using sol-gel in addition with sol gel spin coating technique. The structural, optical and dispersive properties were compared with the already reported work in the literature. The structural properties were observed by using atomic force microscopy (AFM). The AFM images show that the grain size decreases with increasing the concentration of Zn. The highest value of average cluster size (78. 71 nm) was found at 1% and the lowest (60.23 nm) when the doping concentration of Zn was 4%. Similar trend was observed in the roughness of the doped thin film when the Zn concentration was increased. The optical properties were examined using Shimadzu UV-Vis-NIR spectrophotometer and we found that the optical band gap of the un-doped CdO and the Zn-doped CdO thin films increases from 2.54 to 2.62 eV as the Zn concentration is increased from 1% to 4%. Also, the optical dispersion parameters (Eo, Ed, n2∞, λ0 and So) were calculated and discussed. We observed that the refractive index dispersion of undoped CdO and the Zn-doped CdO thin films follow the single oscillator model. Finally, spectroscopic method has been exploited to analyze the 3rd order non-linear optical susceptibility χ (3) and nonlinear refractive index n (2).

  1. Physical and optical properties of binary amorphous selenium-antimony thin films

    Science.gov (United States)

    Sharma, Pankaj; Sharma, Ishu; Katyal, S. C.

    2009-03-01

    Amorphous thin films with compositions Se1-xSbx (x =0, 0.025, 0.05, 0.075, and 0.10 at. %) have been deposited by thermal evaporation (at ˜10-4 Pa) from bulk samples. The compositional dependence of their optical properties, refractive index, extinction coefficient, absorption coefficient, and optical band gap with increasing Sb content is investigated using transmission spectra in the range of 400-1200 nm. The refractive-index dispersion has been analyzed on the basis of the Wemple-DiDomenico single-oscillator approach. It has been found that the refractive index increases with increasing Sb content. The behavior of the optical band gap, when the composition of the material is varied, shows, as expected, just the opposite trends. The optical band gap decreases from 2.025 to 1.753 eV with ±0.001 eV uncertainty. Band gap calculated theoretically also shows a decrease with the increase in Sb content. The optical behavior is supported by physical properties, i.e., decrease in optical band gap is supported by the decrease in cohesive energy of the system. Some other physical properties, viz., coordination number, lone-pair electrons, and glass transition temperature, are also investigated theoretically. The optical results may lead to yield more sensitive detectors based on amorphous selenium, and physical properties may be useful in achieving more stable alloys which are favorable in x-ray imaging applications.

  2. Optical and electrical properties of thin NiO films deposited by reactive magnetron sputtering and spray pyrolysis

    Science.gov (United States)

    Parkhomenko, H. P.; Solovan, M. N.; Mostovoi, A. I.; Orletskii, I. G.; Parfenyuk, O. A.; Maryanchuk, P. D.

    2017-06-01

    Thin NiO films are deposited by reactive magnetron sputtering and spray pyrolysis. The main optical constants, i.e., refractive index n(λ), absorption coefficient α(λ), extinction coefficient k(λ), and thickness d, are determined. The temperature dependence of the resistance of thin films is found, and the activation energy of films deposited by different methods is determined.

  3. Nanostructured pyronin Y thin films as a new organic semiconductor: Linear/nonlinear optics, band gap and dielectric properties

    Energy Technology Data Exchange (ETDEWEB)

    Zahran, H.Y. [Metallurgical Lab.1, Nanoscience Laboratory for Environmental and Bio-medical Applications (NLEBA), Semiconductor Lab., Department of Physics, Faculty of Education, Ain Shams University, Roxy, 11757 Cairo (Egypt); Advanced Functional Materials & Optoelectronic Laboratory (AFMOL), Department of Physics, Faculty of Science, King Khalid University, P.O. Box 9004, Abha (Saudi Arabia); Yahia, I.S., E-mail: dr_isyahia@yahoo.com [Metallurgical Lab.1, Nanoscience Laboratory for Environmental and Bio-medical Applications (NLEBA), Semiconductor Lab., Department of Physics, Faculty of Education, Ain Shams University, Roxy, 11757 Cairo (Egypt); Advanced Functional Materials & Optoelectronic Laboratory (AFMOL), Department of Physics, Faculty of Science, King Khalid University, P.O. Box 9004, Abha (Saudi Arabia); Alamri, F.H. [Advanced Functional Materials & Optoelectronic Laboratory (AFMOL), Department of Physics, Faculty of Science, King Khalid University, P.O. Box 9004, Abha (Saudi Arabia)

    2017-05-15

    Pyronin Y dye (PY) is a kind of xanthene derivatives. Thin films of pyronin Y were deposited onto highly cleaned glass substrates using low-cost/spin coating technique. The structure properties of pyronin Y thin films with different thicknesses were investigated by using X-ray diffraction (XRD) and atomic force microscope (AFM). PY thin films for all the studied thicknesses have an amorphous structure supporting the short range order of the grain size. AFM supports the nanostructure with spherical/clusters morphologies of the investigated thin films. The optical constants of pyronin Y thin films for various thicknesses were studied by using UV–vis–NIR spectrophotometer in the wavelength range 350–2500 nm. The transmittance T(λ), reflectance R(λ) spectral and absorbance (abs(λ)) were obtained for all film thicknesses at room temperature and the normal light incident. These films showed a high transmittance in the wide scale wavelengths. For different thicknesses of the studied thin films, the optical band gaps were determined and their values around 2 eV. Real and imaginary dielectric constants, dissipation factor and the nonlinear optical parameters were calculated in the wavelengths to the range 300–2500 nm. The pyronin Y is a new organic semiconductor with a good optical absorption in UV–vis regions and it is suitable for nonlinear optical applications. - Highlights: • Pyronin Y (PY) nanostructured thin films were deposited by using spin coating technique. • XRD/AFM were used to study the structure of PY films. • The optical band gap was calculated on the basis of Tauc's model. • Linear/nonlinear optical parameters are calculated and interpreted via the applied optical theories. • PY thin films is a new organic semiconductor for its application in optoelectronic devices.

  4. Determination of elastic and thermal properties of a thin nanocrystalline diamond coating using all-optical methods

    Energy Technology Data Exchange (ETDEWEB)

    Sermeus, J.; Verstraeten, B.; Salenbien, R. [KU Leuven-University of Leuven, Soft Matter and Biophysics, Celestijnenlaan 200D, B-3001 Heverlee (Belgium); Pobedinskas, P.; Haenen, K. [Instituut voor Materiaalonderzoek (IMO), Hasselt University, Wetenschapspark 1, 3590 Diepenbeek (Belgium); IMOMEC, IMEC vzw, Wetenschapspark 1, 3590 Diepenbeek (Belgium); Glorieux, C., E-mail: christ.glorieux@fys.kuleuven.be [KU Leuven-University of Leuven, Soft Matter and Biophysics, Celestijnenlaan 200D, B-3001 Heverlee (Belgium)

    2015-09-01

    Results are presented on the thermal and elastic properties of a thin, 1.5 μm, nanocrystalline diamond coating (NCD), deposited on a silicon substrate by microwave plasma enhanced chemical vapor deposition. A combination of two all-optical measurement techniques, impulsive stimulated thermal scattering and grating induced laser beam deflection, was employed to launch and detect surface acoustic waves (SAWs). The relation between the dispersive propagation velocity of SAWs to the coating-substrate geometry is exploited to determine the elastic properties of the NCD coating. The elastic properties are found to be consistent with literature values. The thermal properties of the coating were determined by monitoring the thermal diffusion induced washing away of the laser induced transient surface temperature grating. The transient thermal grating signals were fitted by the low-frequency limit of a thermoelastic model for a multilayer configuration. Similar to the dispersion of the surface acoustic wave velocity, the characteristic time of the thermal diffusion driven grating decay evolves from a coating-dominated value at short grating spacings towards a substrate-dominated value at grating spacings well exceeding the coating thickness. The grating spacing dependence of the corresponding effective thermal diffusivity was experimentally determined and fitted, leading to a value for the thermal diffusivity of the NCD coating α{sub NCD} = 8.4{sub −0.1}{sup +2.7} mm{sup 2}·s{sup −1}, which is an order of magnitude lower than that of the silicon substrate. The low value of the thermal diffusivity is interpreted with a simple touching model. - Highlights: • We investigate a thin nano-crystalline diamond coating. • We used two all optical surface acoustic wave based methods. • We found a young's modulus and density that is in line with literature. • The thermal diffusivity of the NCD coating was 2 orders of magnitude lower than the one of bulk diamond.

  5. Effects of discharge power on the structural and optical properties of TGZO thin films prepared by RF magnetron sputtering technique

    Science.gov (United States)

    Gu, Jin-hua; Lu, Zhou; Zhong, Zhi-you; Long, Lu; Long, Hao

    2016-05-01

    The transparent semiconductors of Ti and Ga-incorporated ZnO (TGZO) thin films were prepared by radio frequency (RF) magnetron sputtering onto glass substrates. The effects of discharge power on the physical properties of thin films are studied. Experimental results show that all nanocrystalline TGZO thin films possess preferential orientation along the (002) plane. The discharge power significantly affects the crystal structure and optical properties of thin films. When the discharge power is 200 W, the TGZO thin film has the optimal crystalline quality and optical properties, with the narrowest full width at half-maximum ( FWHM) of 1.76×10-3 rad, the largest average grain size of 82.4 nm and the highest average transmittance of 84.3% in the visible range. The optical gaps of thin films are estimated by the Tauc's relation and observed to increase firstly and then decrease with the increase of the discharge power. In addition, the optical parameters, including refractive index, extinction coefficient, dielectric function and dissipation factor of the thin films, are determined by optical characterization methods. The dispersion behavior of the refractive index is also analyzed using the Sellmeier's dispersion model.

  6. Plasma deposition of organosilicon polymer thin films with embedded nanosilver for prevention of microbial adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Saulou, Claire [Universite de Toulouse, INSA, UPS, INPT, LISBP, 135 Av. de Rangueil, F-31077 Toulouse (France); Universite de Toulouse, UPS, INPT, LAPLACE, 118 route de Narbonne, F-31062 Toulouse cedex 9 (France); Despax, Bernard; Raynaud, Patrice [Universite de Toulouse, UPS, INPT, LAPLACE, 118 route de Narbonne, F-31062 Toulouse cedex 9 (France); Zanna, Sandrine; Marcus, Philippe [LPCS, UMR CNRS/ENSCP 7045, 11 rue P. et M. Curie, 75005 Paris (France); Mercier-Bonin, Muriel, E-mail: muriel.mercier-bonin@insa-toulouse.fr [Universite de Toulouse, INSA, UPS, INPT, LISBP, 135 Av. de Rangueil, F-31077 Toulouse (France)

    2009-11-15

    Composite thin films ({approx}170 nm) containing silver nanoclusters embedded in an organosilicon matrix were deposited by PE-CVD onto stainless steel in order to prevent microbial adhesion. The process originality relies on a dual strategy combining silver sputtering and simultaneous plasma polymerization in argon-hexamethyldisiloxane (HMDSO) plasma, using an asymmetrical RF glow discharge. The metal content in the film was controlled by varying the HMDSO flow rate. Investigation of the physico-chemical properties of the obtained films was conducted by X-ray photoelectron spectroscopy and transmission FTIR spectroscopy. Plasma-mediated coatings were composed of C, O, Si and Ag which was predominantly under metallic form, as indicated by XPS analysis. The presence of Si-H, Si-O-Si, Si-(CH){sub n}-Si and C-H groups was established by FTIR. The yeast Saccharomyces cerevisiae was selected as the model for eukaryotic microorganisms. The maximal anti-adhesive efficiency was achieved for the organosilicon matrix alone. When nanosilver was incorporated into the organic matrix, the efficiency was reduced, especially for high metal contents. Silver antimicrobial property was assumed to be related to Ag{sup +} progressive release from the embedded nanoparticles into the surrounding medium. This release was confirmed by ICP-MS measurements. Moreover, silver-containing film antifungal activity was observed towards sessile cells.

  7. Boosting persistence time of laser-induced plasma by electric arc discharge for optical emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Eschlböck-Fuchs, S., E-mail: simon.eschlboeck-fuchs@jku.at [Christian Doppler Laboratory for Laser-Assisted Diagnostics, Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz (Austria); Kolmhofer, P.J.; Bodea, M.A.; Hechenberger, J.G.; Huber, N. [Christian Doppler Laboratory for Laser-Assisted Diagnostics, Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz (Austria); Rössler, R. [voestalpine Stahl GmbH, A-4031 Linz (Austria); Pedarnig, J.D., E-mail: johannes.pedarnig@jku.at [Christian Doppler Laboratory for Laser-Assisted Diagnostics, Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz (Austria)

    2015-07-01

    Plasma induced by nanosecond laser ablation is re-excited by a pulsed electric discharge and the parameters and optical emission of the plasma are measured. The discharge is a low-voltage and high-current electric arc that is triggered by the laser-induced plasma and slowly decaying with time. The optical emission of such combined plasma lasts up to several milliseconds which is much longer than without re-excitation (μs range). The emission spectra of re-excited plasma measured on different sample materials show higher line intensities than spectra measured by conventional laser-induced breakdown spectroscopy (LIBS). Moreover, emission lines of fluorine (spectral range 683–691 nm) and sulfur (range 520–550 nm) not detected by conventional LIBS become easily detectable with the combined plasma. The concentration of major components in metallurgical slags, as determined by calibration-free LIBS, agrees very well to the reference data evaluating the spectra taken from re-excited plasma. - Highlights: • Persistence time of laser-induced plasma in air is increased from ~ 10 μs to ~ 1 ms. • Laser-induced plasma triggers an electric arc discharge that boosts the plasma. • The combined laser-arc plasma is in LTE state over very long time (ms range). • CF-LIBS method delivers accurate results evaluating spectra of combined plasma. • Emission from S and F, not detected by LIBS, is detected with combined plasma.

  8. High-energy ion treatments of amorphous As40Se60 thin films for optical applications

    Directory of Open Access Journals (Sweden)

    Rashmi Chauhan

    2014-06-01

    Full Text Available The treatment of 100 MeV Ag swift-heavy ion (SHI irradiation with five different fluences (3×1010, 1×1011, 3×1011, 1×1012, and 3×1012 ions/cm2 was used to design optical and structural properties of amorphous (a- As40Se60 chalcogenide thin films. Swanepoel method was applied on transmission measurements to determine the changes in optical bandgap, Tauc parameter and linear optical parameters, i.e., linear optical absorption, extinction coefficient and linear refractive index. Dispersion of the material was determined by Wemple–DiDomenico relation. Changes in nonlinear optical parameters of third-order optical susceptibility and nonlinear refractive index were determined using semi-empirical relations. Changes in surface morphology of the films were investigated using SEM observation, which indicated that fluence 3×1012 ions/cm2 was upper threshold limit for these films for ion treatment. It is observed that optical bandgap reduces from 1.76 eV to 1.64 eV, and nonlinear refractive index increases from 1.31×10−10 [esu] to 1.74×10−10 [esu]. Linear refractive index initially increases from 2.80 to 3.52 (for fluence 3×1010 ions/cm2 and then keeps decreasing. The observed changes in optical properties upon irradiation were explained in terms of structural rearrangements by Raman measurement. The study was compiled with the previous literature to propose SHI as an effective optical engineering technique to achieve desired changes according to the need of optical/photonic applications.

  9. High-energy ion treatments of amorphous As40Se60 thin films for optical applications

    Institute of Scientific and Technical Information of China (English)

    Rashmi Chauhan; Arvind Tripathi; Krishna Kant Srivastava

    2014-01-01

    The treatment of 100 MeV Ag swift-heavy ion (SHI) irradiation with five different fluences (3 ? 1010, 1 ? 1011, 3 ? 1011, 1 ? 1012, and 3 ? 1012 ions/cm2) was used to design optical and structural properties of amorphous (a-) As40Se60 chalcogenide thin films. Swanepoel method was applied on transmission measurements to determine the changes in optical bandgap, Tauc parameter and linear optical parameters, i.e., linear optical absorption, extinction coefficient and linear refractive index. Dispersion of the material was determined by Wemple-DiDomenico relation. Changes in nonlinear optical parameters of third-order optical susceptibility and nonlinear refractive index were determined using semi-empirical relations. Changes in surface morphology of the films were investigated using SEM observation, which indicated that fluence 3 ? 1012 ions/cm2 was upper threshold limit for these films for ion treatment. It is observed that optical bandgap reduces from 1.76 eV to 1.64 eV, and nonlinear refractive index increases from 1.31 ? 10 ? 10 [esu] to 1.74 ? 10 ? 10 [esu]. Linear refractive index initially increases from 2.80 to 3.52 (for fluence 3 ? 1010 ions/cm2) and then keeps decreasing. The observed changes in optical properties upon irradiation were explained in terms of structural rearrangements by Raman measurement. The study was compiled with the previous literature to propose SHI as an effective optical engineering technique to achieve desired changes according to the need of optical/photonic applications.

  10. Study on Optical Properties of Tin Oxide Thin Film at Different Annealing Temperature

    Directory of Open Access Journals (Sweden)

    Saturi Baco

    2012-07-01

    Full Text Available Tin Oxide (SnO2 thin film is one of the important transparent conducting oxides (TCOs and applied in various fields such as in solar cells, optoelectronic devices, heat mirror, gas sensors, etc due to its electrical and optical transparency in visible light spectrum. In this paper, we presented the optical properties of tin oxide thin film at four different annealing temperatures (373 K, 437 K, 573 K and 673 K prepared by radio frequency sputtering technique. The optical characteristic of these films was investigated using the UV-VIS 3101-PC Spectrophotometer. From this study, all samples exhibit high transmittance more than 70% in the visible light spectrum. Sample annealed at 473 K shows the maximum transmittance which is 87%. Refractive index, n were in the range of 2.33 – 2.80 at  = 550 nm and enhanced with the annealing temperature. However the extinction of coefficient, k was found to be very small. The optical band-edge absorption coefficients were found in the range of 104 – 105cm-1. The energy gap value was decreased with increasing annealing temperature and the type of photon transition was allowed direct transition.

  11. Nonlinear optical properties of poly(methyl methacrylate) thin films doped with Bixa Orellana dye

    Science.gov (United States)

    Zongo, S.; Kerasidou, A. P.; Sone, B. T.; Diallo, A.; Mthunzi, P.; Iliopoulos, K.; Nkosi, M.; Maaza, M.; Sahraoui, B.

    2015-06-01

    Natural dyes with highly delocalized π-electron systems are considered as promising organic materials for nonlinear optical applications. Among these dyes, Bixa Orellana dye with extended π-electron delocalization is one of the most attractive dyes. Bixa Orellana dye-doped Poly(methyl methacrylate) (PMMA) thin films were prepared through spin coating process for linear and nonlinear optical properties investigation. Atomic force microscopy (AFM) was used to evaluate the roughness of the thin films. The optical constants n and k were evaluated by ellipsometric spectroscopy. The refractive index had a maximum of about 1.456 at 508.5, 523.79 and 511.9 nm, while the maximum of k varies from 0.070 to 0.080 with the thickness. The third order nonlinear optical properties of the hybrid Bixa Orellana dye-PMMA polymer were investigated under 30 ps laser irradiation at 1064 nm with a repetition rate of 10 Hz. In particular the third-order nonlinear susceptibility has been determined by means of the Maker Fringes technique. The nonlinear third order susceptibility was found to be 1.00 × 10-21 m2 V-2 or 0.72 × 10-13 esu. Our studies provide concrete evidence that the hybrid-PMMA composites of Bixa dye are prospective candidates for nonlinear material applications.

  12. Experimental investigation of the thin fiber-optic hydrophone array based on fiber Bragg gratings

    Science.gov (United States)

    Lavrov, Vladimir S.; Plotnikov, Mikhail Y.; Aksarin, Stanislav M.; Efimov, Mikhail E.; Shulepov, Vladimir A.; Kulikov, Andrey V.; Kireenkov, Alexander U.

    2017-03-01

    The paper presents the results of experimental investigations of the fiber optic hydrophone array consisting of six sensors, placed in one thin sensitive cable. Sensors were formed by pairs of Bragg gratings spaced 1.5 m apart and recorded in a birefringent optical fiber with the elliptical stressed coating. To form an extended sensor array the optical fiber was additionally covered with a silicone material RTV655 and protective coatings. Experimental investigations of the array showed that fiber-optic sensors pressure sensitivity increases as the acoustic frequency decreases at average value from -169.4 dB re rad/uPa at 495 Hz to -143.7 dB re rad/uPa at 40 Hz. The minimum detectable pressure was at average value from 53 mPa/√Hz at 495 Hz to 8.3 mPa/√Hz at 40 Hz. The obtained results might be used for developing and producing long thin hydroacoustic arrays for geophysical investigations and other hydroacoustic applications.

  13. Preparation, structure and optical properties of transparent conducting gallium-doped zinc oxide thin films

    Directory of Open Access Journals (Sweden)

    Gu J. H.

    2015-09-01

    Full Text Available Highly conductive gallium-doped zinc oxide (GZO transparent thin films were deposited on glass substrates by RF mag­netron sputtering. The deposited films were characterized by X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS, four-point probe and UV-Vis spectrophotometer, respectively. The effect of growth temperature on the structure and optoelectrical properties of the films was investigated. The results demonstrate that high quality GZO films oriented with their crystal­lographic c-axis perpendicular to the substrates are obtained. The structure and optoelectrical properties of the films are highly dependent on the growth temperature. It is found that with increasing growth temperature, the average visible transmittance of the deposited films is enhanced and the residual stress in the thin films is obviously relaxed. The GZO films deposited at the growth temperature of 400°C, which have the largest grain size (74.3 nm, the lowest electrical resistivity (1.31×10-3 Ω·cm and the maximum figure of merit (1.46×1O-2Ω-1, exhibit the best optoelectrical properties. Furthermore, the optical proper­ties of the deposited films were determined by the optical characterization methods and the optical energy-gaps were evaluated by extrapolation method. A blue shift of the optical energy gap is observed with an increase in the growth temperature.

  14. Engineering of electronic and optical properties of PbS thin films via Cu doping

    Science.gov (United States)

    Touati, Baligh; Gassoumi, Abdelaziz; Dobryden, Illia; Natile, Marta Maria; Vomiero, Alberto; Turki, Najoua Kamoun

    2016-09-01

    Copper-doped PbS polycrystalline thin films were deposited by chemical bath deposition by adding small amount of Cu (ysolution = [Cu2+]/[Pb2+]) between 0.5 and 2 at%. The composition, structure, morphology, optical and electrical properties of the films were investigated by means of X-ray diffraction (XRD), Rutherford backscattering spectrometry (RBS), atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray photoemission spectroscopy (XPS), UV-visible-near infrared (UV-Vis-NIR) spectrophotometry and Hall effect measurements. The XRD studies showed that the undoped films have PbS face centered cubic structure with (111) preferential orientation, while preferential orientation changes to (200) plane with increasing Cu doping concentration. The AFM and SEM measurements indicated that the film surfaces consisted of nanosized grains with pyramidal shape. Optical band gap was blue shifted from 0.72 eV to 1.69 eV with the increase in Cu doping concentration. The film obtained with the [Cu2+]/[Pb2+] ratio equal to 1.5 at% Cu showed the minimum resistivity of 0.16 Ω cm at room temperature and optimum value of optical band gap close to 1.5 eV. 1.5 at% Cu-doped PbS thin films exhibit the best optical and electrical properties, suitable for solar cells applications.

  15. Photostability of plasma polymerized γ-terpinene thin films for encapsulation of OPV

    Science.gov (United States)

    Bazaka, Kateryna; Ahmad, Jakaria; Oelgemöller, Michael; Uddin, Ashraf; Jacob, Mohan V.

    2017-03-01

    Optically transparent, smooth, defect-free, chemically inert and with good adhesion to a variety of substrates, plasma polymers from plant-derived secondary metabolites have been identified as promising encapsulating materials for organic electronics and photovoltaics. Here, we demonstrate that an encapsulating layer of plasma polymerized γ-terpinene reduces degradation-related loss in conversion efficiency in PCPDTBT:PC70BM solar cells under ambient operating conditions. The stability of γ-terpinene films was then investigated under extreme UV irradiation conditions as a function of deposition power. When exposed to ambient air, prolonged exposure to UV-A and UV-B light led to notable ageing of the polymer. Photooxidation was identified as the main mechanism of degradation, confirmed by significantly slower ageing when oxygen was restricted through the use of a quartz cover. Under unnatural high-energy UV-C irradiation, significant photochemical degradation and oxidation occurred even in an oxygen-poor environment.

  16. Photostability of plasma polymerized γ-terpinene thin films for encapsulation of OPV

    Science.gov (United States)

    Bazaka, Kateryna; Ahmad, Jakaria; Oelgemöller, Michael; Uddin, Ashraf; Jacob, Mohan V.

    2017-01-01

    Optically transparent, smooth, defect-free, chemically inert and with good adhesion to a variety of substrates, plasma polymers from plant-derived secondary metabolites have been identified as promising encapsulating materials for organic electronics and photovoltaics. Here, we demonstrate that an encapsulating layer of plasma polymerized γ-terpinene reduces degradation-related loss in conversion efficiency in PCPDTBT:PC70BM solar cells under ambient operating conditions. The stability of γ-terpinene films was then investigated under extreme UV irradiation conditions as a function of deposition power. When exposed to ambient air, prolonged exposure to UV–A and UV–B light led to notable ageing of the polymer. Photooxidation was identified as the main mechanism of degradation, confirmed by significantly slower ageing when oxygen was restricted through the use of a quartz cover. Under unnatural high-energy UV–C irradiation, significant photochemical degradation and oxidation occurred even in an oxygen-poor environment. PMID:28358138

  17. Structural and optical studies on antimony and zinc doped CuInS2 thin films

    Science.gov (United States)

    Ben Rabeh, M.; Chaglabou, N.; Kanzari, M.; Rezig, B.

    2009-11-01

    The influence of Zn and Sb impurities on the structural, optical and electrical properties of CuInS2 thin films on corning 7059 glass substrates was studied. Undoped and Zn or Sb doped CuInS2 thin films were deposited by thermal evaporation method and annealed in vacuum at temperature of 450 ∘C Undoped thin films were grown from CuInS2 powder using resistively heated tungsten boats. Zn species was evaporated from a thermal evaporator all together to the CuInS2 powder and Sb species was mixed in the starting powders. The amount of the Zn or Sb source was determined to be in the range 0-4 wt% molecular weight compared with the CuInS2 alloy source. The films were studied by means of X-ray diffraction (XRD), Optical reflection and transmission and resistance measurements. The films thicknesses were in the range 450-750 nm. All the Zn: CuInS2 and Sb: CuInS2 thin films have relatively high absorption coefficient between 104 cm-1 and 105 cm-1 in the visible and the near-IR spectral range. The bandgap energies are in the range of 1.472-1.589 eV for Zn: CuInS2 samples and 1.396-1.510 eV for the Sb: CuInS2 ones. The type of conductivity of these films was determined by the hot probe method. Furthermore, we found that Zn and Sb-doped CuInS2 thin films exhibit P type conductivity and we predict these species can be considered as suitable candidates for use as acceptor dopants to fabricate CuInS2-based solar cells.

  18. Electronic excitation induced modifications of optical and morphological properties of PCBM thin films

    Science.gov (United States)

    Sharma, T.; Singhal, R.; Vishnoi, R.; Sharma, P.; Patra, A.; Chand, S.; Lakshmi, G. B. V. S.; Biswas, S. K.

    2016-07-01

    Phenyl C61 butyric acid methyl ester (PCBM) is a fullerene derivative and most commonly used in organic photovoltaic devices both as electron acceptor and transporting material due to high electron mobility. PCBM is easy to spin caste on some substrate as it is soluble in chlorobenzene. In this study, the spin coated thin films of PCBM (on two different substrate, glass and double sided silicon) were irradiated using 90 MeV Ni7+ swift heavy ion beam at low fluences ranging from 1 × 109 to 1 × 1011 ions/cm2 to study the effect of ion beam irradiation. The pristine and irradiated PCBM thin films were characterized by UV-visible absorption spectroscopy and fourier transform infrared spectroscopy (FTIR) to investigate the optical properties before and after irradiation. These thin films were further analyzed using atomic force microscopy (AFM) to investigate the morphological modifications which are induced by energetic ions. The variation in optical band gap after irradiation was measured using Tauc's relation from UV-visible absorption spectra. A considerable change was observed with increasing fluence in optical band gap of irradiated thin films of PCBM with respect to the pristine film. The decrease in FTIR band intensity of C60 cage reveals the polymerization reaction due to high energy ion impact. The roughness is also found to be dependent on incident fluences. This study throws light for the application of PCBM in organic solar cells in form of ion irradiation induced nanowires of PCBM for efficient charge carrier transportation in active layer.

  19. Adhesion improvement of hydrogenated diamond-like carbon thin films by pre-deposition plasma treatment of rubber substrate

    OpenAIRE

    Bui, X. L.; Pei, Y.T.; Mulder, E.D.G.; De Hosson, J. Th. M.

    2009-01-01

    For reduction of friction and enhancement of wear resistance of dynamic rubber seals, thin films of hydrogenated diamond-like carbon (DLC) have been deposited on hydrogenated nitrile butadiene rubber (HNBR) via magnetron-enhanced plasma chemical vapor deposition (ME-PCVD). Pre-deposition plasma treatment of HNBR substrate is proved to be crucial for the improvement of film performance due to enhanced interfacial adhesion. The columnar structure and the crack network formed during deposition e...

  20. Large Optical Telescope Based on High Efficiency Thin Film Planar Diffractive Optics Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In future ground-based receivers for deep-space optical communications with spacecraft, aperture diameters of the order of 10 meters are required even with the most...