Fabrication and Characterisation of Flexible Coaxial Thin Thread Supercapacitors

Directory of Open Access Journals (Sweden)

Fulian Qiu

2014-08-01

Full Text Available Flexible coaxial thin thread supercapacitors were fabricated semi-automatically using a dip coating method. A typical coaxial thin thread supercapacitor of a length of 70 cm demonstrated a specific length capacitance of 0.3 mF cm-1 (11.2 mF cm-2 and 2.18 F cm-3 at 5 mV s-1, the device exhibited good electrochemical performance with a high volume energy density of 0.22 mWh cm-3 at a power density of 22 mW cm-3. Thread supercapacitors were assembled in series and parallel combinations, the accepted models for series and parallel circuit combinations were obeyed for two coaxial thread supercapacitors. The thread shows high flexibility and uniformity of specific length capacitance, one integrated with a commercial solar cell could be charged and power a LED. The process is simple, robust and easy to scale up to make unlimited length thread supercapacitors for numerous miniaturized and flexible electronic applications.

Tin oxide transparent thin-film transistors

International Nuclear Information System (INIS)

Presley, R E; Munsee, C L; Park, C-H; Hong, D; Wager, J F; Keszler, D A

2004-01-01

A SnO 2 transparent thin-film transistor (TTFT) is demonstrated. The SnO 2 channel layer is deposited by RF magnetron sputtering and then rapid thermal annealed in O 2 at 600 deg. C. The TTFT is highly transparent, and enhancement-mode behaviour is achieved by employing a very thin channel layer (10-20 nm). Maximum field-effect mobilities of 0.8 cm 2 V -1 s -1 and 2.0 cm 2 V -1 s -1 are obtained for enhancement- and depletion-mode devices, respectively. The transparent nature and the large drain current on-to-off ratio of 10 5 associated with the enhancement-mode behaviour of these devices may prove useful for novel gas-sensor applications

Quinoline-Flanked Diketopyrrolopyrrole Copolymers Breaking through Electron Mobility over 6 cm2 V-1 s-1 in Flexible Thin Film Devices.

Science.gov (United States)

Ni, Zhenjie; Dong, Huanli; Wang, Hanlin; Ding, Shang; Zou, Ye; Zhao, Qiang; Zhen, Yonggang; Liu, Feng; Jiang, Lang; Hu, Wenping

2018-03-01

Herein, the design and synthesis of novel π-extended quinoline-flanked diketopyrrolopyrrole (DPP) [abbreviated as QDPP] motifs and corresponding copolymers named PQDPP-T and PQDPP-2FT for high performing n-type organic field-effect transistors (OFETs) in flexible organic thin film devices are reported. Serving as DPP-flankers in backbones, quinoline is found to effectively tune copolymer optoelectric properties. Compared with TDPP and pyridine-flanked DPP (PyDPP) analogs, widened bandgaps and strengthened electron deficiency are achieved. Moreover, both hole and electron mobility are improved two orders of magnitude compared to those of PyDPP analogs (PPyDPP-T and PPyDPP-2FT). Notably, featuring an all-acceptor-incorporated backbone, PQDPP-2FT exhibits electron mobility of 6.04 cm 2 V -1 s -1 , among the highest value in OFETs fabricated on flexible substrates to date. Moreover, due to the widened bandgap and strengthened electron deficiency of PQDPP, n-channel on/off ratio over 10 5 with suppressed hole transport is first realized in the ambipolar DPP-based copolymers. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Porous CrN thin films by selectively etching CrCuN for symmetric supercapacitors

Science.gov (United States)

Wei, Binbin; Mei, Gui; Liang, Hanfeng; Qi, Zhengbing; Zhang, Dongfang; Shen, Hao; Wang, Zhoucheng

2018-05-01

Transition metal nitrides are regarded as a new class of excellent electrode materials for high-performance supercapacitors due to their superior chemical stability and excellent electrical conductivity. We synthesize successfully the porous CrN thin films for binder-free supercapacitor electrodes by reactive magnetron co-sputtering and selective chemical etching. The porous CrN thin film electrodes exhibit high-capacitance performance (31.3 mF cm-2 at 1.0 mA cm-2) and reasonable cycling stability (94% retention after 20000 cycles). Moreover, the specific capacitance is more than two-fold higher than that of the CrN thin film electrodes in previous work. In addition, a symmetric supercapacitor device with a maximum energy density of 14.4 mWh cm-3 and a maximum power density of 6.6 W cm-3 is achieved. These findings demonstrate that the porous CrN thin films will have potential applications in supercapacitors.

Subtle Raman signals from nano-diamond and β-SiC thin films

International Nuclear Information System (INIS)

Kuntumalla, Mohan Kumar; Ojha, Harish; Srikanth, Vadali Venkata Satya Siva

2013-01-01

Micro Raman scattering experiments are carried out in pursuit of subtle but discernable signals from nano-diamond and β-SiC thin films. The thin films are synthesized using microwave plasma assisted chemical vapor deposition technique. Raman scattering experiments in conjunction with scanning electron microscopy and x-ray diffraction were carried out to extract microstructure and phase information of the above mentioned thin films. Certain subtle Raman signals have been identified in this work. In the case of nanodiamond thin films, Raman bands at ∼ 485 and ∼ 1220 cm −1 are identified. These bands have been assigned to the nanodiamond present in nanodiamond thin films. In the case of nano β-SiC thin films, optical phonons are identified using surface enhanced Raman scattering. - Highlights: ► Subtle Raman signals from nano-diamond and β-silicon carbide related thin films. ► Raman bands at ∼ 485 and ∼ 1220 cm −1 from nanodiamond thin films are identified. ► Longitudinal optical phonon from nano β-silicon carbide thin films is identified

Gain and time resolution of 45 μm thin Low Gain Avalanche Detectors before and after irradiation up to a fluence of 1015 neq/cm2

International Nuclear Information System (INIS)

Lange, J.; Cavallaro, E.; Förster, F.; Grinstein, S.; Carulla, M.; Flores, D.; Hidalgo, S.; Merlos, A.; Pellegrini, G.; Quirion, D.; Chytka, L.; Komarek, T.; Nozka, L.; Davis, P.M.; Kramberger, G.; Mandić, I.; Sykora, T.

2017-01-01

Low Gain Avalanche Detectors (LGADs) are silicon sensors with a built-in charge multiplication layer providing a gain of typically 10 to 50. Due to the combination of high signal-to-noise ratio and short rise time, thin LGADs provide good time resolutions. LGADs with an active thickness of about 45 μm were produced at CNM Barcelona. Their gains and time resolutions were studied in beam tests for two different multiplication layer implantation doses, as well as before and after irradiation with neutrons up to 10 15 n eq /cm 2 . The gain showed the expected decrease at a fixed voltage for a lower initial implantation dose, as well as for a higher fluence due to effective acceptor removal in the multiplication layer. Time resolutions below 30 ps were obtained at the highest applied voltages for both implantation doses before irradiation. Also after an intermediate fluence of 3×10 14 n eq /cm 2 , similar values were measured since a higher applicable reverse bias voltage could recover most of the pre-irradiation gain. At 10 15 n eq /cm 2 , the time resolution at the maximum applicable voltage of 620 V during the beam test was measured to be 57 ps since the voltage stability was not good enough to compensate for the gain layer loss. The time resolutions were found to follow approximately a universal function of gain for all implantation doses and fluences.

Velocities of dislocation groups in very thin neutron-irradiated copper single crystals measured by slip line cinematography

Energy Technology Data Exchange (ETDEWEB)

Potthoff, H.H. (Technische Univ. Braunschweig (Germany, F.R.). Inst. fuer Metallphysik und Nukleare Festkoerperphysik)

1983-05-16

Slip line development on very thin flat single crystals of neutron-irradiated Cu (thickness down to only 15 to 20 ..mu..m, orientation for single glide, yield region, room temperature) is recorded by high-speed cinematography during tensile deformation. In such very thin crystals glide dislocations on the slip plane must be arranged in a rather simple way. Drops in tensile load occuring during initiation of single slip lines at the Lueders band front indicate that in the beginning of a slip line development dislocation groups traverse the whole glide plane in very short times. Evaluating the data measured for the slip line growth v/sub s/ >= 10 cm/s is found for screw dislocations and v/sub e/ >= v/sub s/ for edge dislocations. For later stages on thin crystals and for all stages on thick crystals (>= several 100 ..mu..m) slip line development is much slower and slip line show many cross slip events which then appear to control the mean velocity of the dislocations.

Development of CIGS2 thin film solar cells

International Nuclear Information System (INIS)

Dhere, Neelkanth G.; Gade, Vivek S.; Kadam, Ankur A.; Jahagirdar, Anant H.; Kulkarni, Sachin S.; Bet, Sachin M.

2005-01-01

Research and development of CuIn 1-x Ga x Se 2-y S y (CIGSS) thin-film solar cells on ultralightweight flexible metallic foil substrates is being carried out at FSEC PV Materials Lab for space applications. Earlier, the substrate size was limited to 3 cm x 2.5 cm. Large-area sputtering systems and scrubber for hydrogen selenide and sulfide have been designed and constructed for preparation of CIGSS thin-films on large (15 cm x 10 cm) substrates. A selenization/sulfurization furnace donated by Shell (formerly Siemens) Solar has also been refurbished and upgraded. The sputtering target assembly design was modified for proper clamping of targets and effective cooling. A new design of the magnetic assembly for large-area magnetron sputtering sources was implemented so as to achieve uniform deposition on large area. Lightweight stainless steel foil and ultralightweight titanium foil substrates were utilized to increase the specific power of solar cells. Sol-gel derived SiO 2 layers were coated on titanium foil by dip coating method. Deposition parameters for the preparation of molybdenum back contact layers were optimized so as to minimize the residual stress as well as reaction with H 2 S. Presently large (15 cm x 10 cm) CuIn 1-x Ga x S 2 (CIGS2) thin film solar cells are being prepared on Mo-coated titanium and stainless steel foil by sulfurization of CuGa/In metallic precursors in diluted Ar:H 2 S(4%). Heterojunction partner CdS layers are deposited by chemical bath deposition. The regeneration sequence of ZnO/ZnO:Al targets was optimized for obtaining consistently good-quality, transparent and conducting ZnO/ZnO:Al bilayer by RF magnetron-sputter deposition. Excellent facilities at FSEC PV Materials Lab are one of its kinds and could serve as a nucleus of a small pilot plant for CIGSS thin film solar cell fabrication

Ferroelectric properties of PZT/BFO multilayer thin films prepared using the sol-gel method.

Science.gov (United States)

Jo, Seo-Hyeon; Lee, Sung-Gap; Lee, Young-Hie

2012-01-05

In this study, Pb(Zr0.52Ti0.48)O3/BiFeO3 [PZT/BFO] multilayer thin films were fabricated using the spin-coating method on a Pt(200 nm)/Ti(10 nm)/SiO2(100 nm)/p-Si(100) substrate alternately using BFO and PZT metal alkoxide solutions. The coating-and-heating procedure was repeated several times to form the multilayer thin films. All PZT/BFO multilayer thin films show a void-free, uniform grain structure without the presence of rosette structures. The relative dielectric constant and dielectric loss of the six-coated PZT/BFO [PZT/BFO-6] thin film were approximately 405 and 0.03%, respectively. As the number of coatings increased, the remanent polarization and coercive field increased. The values for the BFO-6 multilayer thin film were 41.3 C/cm2 and 15.1 MV/cm, respectively. The leakage current density of the BFO-6 multilayer thin film at 5 V was 2.52 × 10-7 A/cm2.

Optical and electrical properties of transparent conducting B-doped ZnO thin films prepared by various deposition methods

International Nuclear Information System (INIS)

Nomoto, Jun-ichi; Miyata, Toshihiro; Minami, Tadatsugu

2011-01-01

B-doped ZnO (BZO) thin films were prepared with various thicknesses up to about 500 nm on glass substrates at 200 deg. C by dc or rf magnetron sputtering deposition, pulsed laser deposition (PLD), and vacuum arc plasma evaporation (VAPE) methods. Resistivities of 4-6 x 10 -4 Ω cm were obtained in BZO thin films prepared with a B content [B/(B + Zn) atomic ratio] around 1 at. % by PLD and VAPE methods: Hall mobilities above 40 cm 2 /Vs and carrier concentrations on the order of 10 20 cm -3 . All 500-nm-thick-BZO thin films prepared with a resistivity on the order of 10 -3 -10 -4 Ω cm exhibited an averaged transmittance above 80% in the wavelength range of 400-1100 nm. The resistivity in BZO thin films prepared with a thickness below about 500 nm was found to increase over time with exposure to various high humidity environments. In heat-resistance tests, the resistivity stability of BZO thin films was found to be nearly equal to that of Ga-doped ZnO thin films, so these films were judged suitable for use as a transparent electrode for thin-film solar cells.

ITO thin films deposited by advanced pulsed laser deposition

International Nuclear Information System (INIS)

Viespe, Cristian; Nicolae, Ionut; Sima, Cornelia; Grigoriu, Constantin; Medianu, Rares

2007-01-01

Indium tin oxide thin films were deposited by computer assisted advanced PLD method in order to obtain transparent, conductive and homogeneous films on a large area. The films were deposited on glass substrates. We studied the influence of the temperature (room temperature (RT)-180 deg. C), pressure (1-6 x 10 -2 Torr), laser fluence (1-4 J/cm 2 ) and wavelength (266-355 nm) on the film properties. The deposition rate, roughness, film structure, optical transmission, electrical conductivity measurements were done. We deposited uniform ITO thin films (thickness 100-600 nm, roughness 5-10 nm) between RT and 180 deg. C on a large area (5 x 5 cm 2 ). The films have electrical resistivity of 8 x 10 -4 Ω cm at RT, 5 x 10 -4 Ω cm at 180 deg. C and an optical transmission in the visible range, around 89%

Preparation of Zinc Oxide (ZnO) Thin Film as Transparent Conductive Oxide (TCO) from Zinc Complex Compound on Thin Film Solar Cells: A Study of O2 Effect on Annealing Process

Science.gov (United States)

Muslih, E. Y.; Kim, K. H.

2017-07-01

Zinc oxide (ZnO) thin film as a transparent conductive oxide (TCO) for thin film solar cell application was successfully prepared through two step preparations which consisted of deposition by spin coating at 2000 rpm for 10 second and followed by annealing at 500 °C for 2 hours under O2 and ambient atmosphere. Zinc acetate dehydrate was used as a precursor which dissolved in ethanol and acetone (1:1 mol) mixture in order to make a zinc complex compound. In this work, we reported the O2 effect, reaction mechanism, structure, morphology, optical and electrical properties. ZnO thin film in this work shows a single phase of wurtzite, with n-type semiconductor and has band gap, carrier concentration, mobility, and resistivity as 3.18 eV, 1.21 × 10-19cm3, 11 cm2/Vs, 2.35 × 10-3 Ωcm respectively which is suitable for TCO at thin film solar cell.

Low-density silicon thin films for lithium-ion battery anodes

Energy Technology Data Exchange (ETDEWEB)

Demirkan, M.T., E-mail: tmdemirkan@ualr.edu [Department of Physics and Astronomy, University of Arkansas at Little Rock, Little Rock, AR 72204 (United States); Department of Materials Science and Engineering, Gebze Technical University, Kocaeli (Turkey); Trahey, L. [Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Karabacak, T. [Department of Physics and Astronomy, University of Arkansas at Little Rock, Little Rock, AR 72204 (United States)

2016-02-01

Density of sputter deposited silicon (Si) thin films was changed by a simple working gas pressure control process, and its effects on the cycling performance of Si films in Li-ion batteries as anodes was investigated. Higher gas pressure results in reduced film densities due to a shadowing effect originating from lower mean free path of sputter atoms, which leads to a wider angular distribution of the incoming flux and formation of a porous film microstructure. Si thin film anodes of different densities ranging from 2.27 g/cm{sup 3} (film porosity ~ 3%) down to 1.64 g/cm{sup 3} (~ 30% porosity) were fabricated by magnetron sputtering at argon pressures varying from 0.2 Pa to 2.6 Pa, respectively. High density Si thin film anodes of 2.27 g/cm{sup 3} suffered from an unstable cycling behavior during charging/discharging depicted by a continuous reduction in specific down to ~ 830 mAh/g at the 100th cycle. Electrochemical properties of lower density films with 1.99 g/cm{sup 3} (~ 15% porosity) and 1.77 g/cm{sup 3} (~ 24% porosity) got worse resulting in only ~ 100 mAh/g capacity at 100th cycle. On the other hand, as the density of anode was further reduced down to about 1.64 g/cm{sup 3} (~ 30% porosity), cycling stability and capacity retention significantly improved resulting in specific capacity values ~ 650 mAh/g at 100th cycle with coulombic efficiencies of > 98%. Enhancement in our low density Si film anodes are believed to mainly originate from the availability of voids for volumetric expansion during lithiation and resulting compliant behavior that provides superior mechanical and electrochemical stability. - Highlights: • Low density Si thin films were studied as Li-ion battery anodes. • Low density Si films were fabricated by magnetron sputter deposition. • Density of Si films reduced down to as low as ~ 1.64 g/cm{sup 3} with a porosity of ~ 30% • Low density Si films presented superior mechanical properties during cycling.

Solar cell fabricated on welded thin flexible silicon

Directory of Open Access Journals (Sweden)

Hessmann Maik Thomas

2015-01-01

Full Text Available We present a thin-film crystalline silicon solar cell with an AM1.5 efficiency of 11.5% fabricated on welded 50 μm thin silicon foils. The aperture area of the cell is 1.00 cm2. The cell has an open-circuit voltage of 570 mV, a short-circuit current density of 29.9 mA cm-2 and a fill factor of 67.6%. These are the first results ever presented for solar cells on welded silicon foils. The foils were welded together in order to create the first thin flexible monocrystalline band substrate. A flexible band substrate offers the possibility to overcome the area restriction of ingot-based monocrystalline silicon wafers and the feasibility of a roll-to-roll manufacturing. In combination with an epitaxial and layer transfer process a decrease in production costs can be achieved.

Preparation of Pb(Zr, Ti)O3 Thin Films on Glass Substrates

Science.gov (United States)

Hioki, Tsuyoshi; Akiyama, Masahiko; Ueda, Tomomasa; Onozuka, Yutaka; Hara, Yujiro; Suzuki, Kouji

2000-09-01

Lead-zirconate-titanate (PZT) thin films were prepared on non-alkaline glass substrates widely used in liquid crystal display (LCD) devices, by plasma-assisted magnetron RF sputtering with an immersed coil. After preparation of the PZT thin film, the glass was available for use in LCD device processing. No mutual diffusion of the elements was recognized between the glass substrate and the bottom electrode. The PZT layer had a dense film structure with rectangular and columnar grains, and only its perovskite phase was crystalline. PZT thin films on a glass substrate had leakage current densities of about 10-8 A/cm2, acceptable hysteresis loop shapes with the remanent polarization (Pr) of 45 μC/cm2 and the coercive field (Ec) of 90 kV/cm. Ferroelectric properties on a glass substrate almost conform with those on a Si-based substrate.

Improved photoelectrochemical performance of BiVO4/MoO3 heterostructure thin films

Science.gov (United States)

Kodan, Nisha; Mehta, B. R.

2018-05-01

Bismuth vanadate (BiVO4) and Molybdenum trioxide (MoO3) thin films have been prepared by RF sputtering technique. BiVO4 thin films were deposited on indium doped tin oxide (In: SnO2; ITO) substrates at room temperature and 80W applied rf power. The prepared BiVO4 thin films were further annealed at 450°C for 2 hours in air to obtain crystalline monoclinic phase and successively coated with MoO3 thin films deposited at 150W rf power and 400°C for 30 minutes. The effect of coupling BiVO4 and MoO3 on the structural, optical and photoelectrochemical (PEC) properties have been studied. Optical studies reveal that coupling of BiVO4 and MoO3 results in improvement of optical absorption in visible region of solar spectrum. PEC study shows approximate 3-fold and 38-fold increment in photocurrent values of BiVO4/MoO3 (0.38 mA/cm2) heterostructure thin film as compared to MoO3 (0.15 mA/cm2) and BiVO4 (10 µA/cm2) thin films at applied bias of 1 V vs Ag/AgCl in 0.5 M Na2SO4 (pH=7) electrolyte.

Changes in Soil Carbon and Moisture over the Six Year after Thinning of a Natural Oak Forest

Science.gov (United States)

Kim, S.; Han, S. H.; Li, G.; Chang, H.; Kim, H. J.; Son, Y.

2017-12-01

The objective of this study was to assess the effects of thinning on soil carbon (C) in a natural oak forest in central Korea. The study forest received three different thinning treatments consisting of un-thinned control (UTC) and two thinning intensities (15% and 30% basal area reductions) in March in 2010. Precipitation near the study forest maintained the normal level from 2010 to 2013 (average 1,400 mm year-1), but abnormally decreased from 2014 to 2016 (average 800 mm year-1). To measure total soil C stock and soil moisture conditions, soils were collected from 0-10, 10-20, and 20-30 cm depths in June, 2010, 2013, and 2016, respectively. Soil microbial biomass C and C-cycling enzymes (β-glucosidase, cellobiohydrolase, β-xylosidase, phenol oxidase, and peroxidase) at 0-10 cm depth were determined in June, 2016. Total soil C stock at 0-30 cm depth increased throughout the study period, whereas soil moisture decreased at all depths from 2013 to 2016. Both thinning treatments had higher total soil C stock at 0-30 cm depth and moisture at 10-20 and 20-30 cm depths than the UTC in 2013 and 2016, whereas the treatments showed no effects in 2010. Microbial biomass C at 0-10 cm depth in 2016 also increased because of the thinning treatments, which was positively correlated to total soil C stock. However, any effects of thinning on C-cycling enzymes were not significant. Our results indicate that thinning could contribute to relieving the impacts of decreasing precipitation by enhancing the storage of soil moisture. Furthermore, the change in total soil C stock under thinning might result from the stimulation of microbial potential for retaining organic C as a form of biomass. This study was supported by the Ministry of Environment (2014001810002) and the National Institute of Forest Science of Korea (FM0101-2009-01).

Raman spectroscopy of ZnMnO thin films grown by pulsed laser deposition

Science.gov (United States)

Orozco, S.; Riascos, H.; Duque, S.

2016-02-01

ZnMnO thin films were grown by Pulsed Laser Deposition (PLD) technique onto Silicon (100) substrates at different growth conditions. Thin films were deposited varying Mn concentration, substrate temperature and oxygen pressure. ZnMnO samples were analysed by using Raman Spectroscopy that shows a red shift for all vibration modes. Raman spectra revealed that nanostructure of thin films was the same of ZnO bulk, wurzite hexagonal structure. The structural disorder was manifested in the line width and shape variations of E2(high) and E2(low) modes located in 99 and 434cm-1 respectively, which may be due to the incorporation of Mn ions inside the ZnO crystal lattice. Around 570cm-1 was found a peak associated to E1(LO) vibration mode of ZnO. 272cm-1 suggest intrinsic host lattice defects. Additional mode centred at about 520cm-1 can be overlap of Si and Mn modes.

LPCVD homoepitaxy of Si doped β-Ga2O3 thin films on (010) and (001) substrates

Science.gov (United States)

Rafique, Subrina; Karim, Md Rezaul; Johnson, Jared M.; Hwang, Jinwoo; Zhao, Hongping

2018-01-01

This paper presents the homoepitaxy of Si-doped β-Ga2O3 thin films on semi-insulating (010) and (001) Ga2O3 substrates via low pressure chemical vapor deposition with a growth rate of ≥1 μm/h. Both high resolution scanning transmission electron microscopy and X-ray diffraction measurements demonstrated high crystalline quality homoepitaxial growth of these thin films. Atomic resolution STEM images of the as-grown β-Ga2O3 thin films on (010) and (001) substrates show high quality material without extended defects or dislocations. The charge carrier transport properties of the as-grown Si-doped β-Ga2O3 thin films were characterized by the temperature dependent Hall measurement using van der Pauw patterns. The room temperature carrier concentrations achieved for the (010) and (001) homoepitaxial thin films were ˜1.2 × 1018 cm-3 and ˜9.5 × 1017 cm-3 with mobilities of ˜72 cm2/V s and ˜42 cm2/V s, respectively.

Amorphous indium gallium zinc oxide thin film grown by pulse laser deposition technique

Energy Technology Data Exchange (ETDEWEB)

Mistry, Bhaumik V., E-mail: bhaumik-phy@yahoo.co.in; Joshi, U. S. [Department of Physics, University School of Sciences, Gujarat University, Ahmedabad-380 009 (India)

2016-05-23

Highly electrically conducting and transparent in visible light IGZO thin film were grown on glass substrate at substrate temperature of 400 C by a pulse laser deposition techniques. Structural, surface, electrical, and optical properties of IGZO thin films were investigated at room temperature. Smooth surface morphology and amorphous nature of the film has been confirmed from the AFM and GIXRD analysis. A resistivity down to 7.7×10{sup −3} V cm was reproducibly obtained while maintaining optical transmission exceeding 70% at wavelengths from 340 to 780 nm. The carrier densities of the film was obtain to the value 1.9×10{sup 18} cm{sup 3}, while the Hall mobility of the IGZO thin film was 16 cm{sup 2} V{sup −1}S{sup −1}.

Structure and electrical properties of (La, Zn) Co-doped BiFeO3 thin films prepared by using chemical solution deposition

Science.gov (United States)

Kim, Y. J.; Kim, H. J.; Kim, J. W.; Raghavan, C. M.; Kim, S. S.

2012-08-01

We prepared pure BiFeO3 (BFO) and (Bi0.9La0.1)(Fe0.975Zn0.025)O3- δ (BLFZO) thin films on Pt(111)/Ti/SiO2/Si(100) substrates by using a chemical solution deposition method. Improved electrical properties were observed in the co-doped BLFZO thin film. The leakage current density of the BLFZO thin film was four orders of magnitude lower than that of the pure BFO, 4.17 × 10-7 A/cm2 at 100 kV/cm. The remnant polarization (2 P r ) and the coercive electric field (2 E c ) of the BLFZO thin film were 97 µC/cm2 and 903 kV/cm at an applied electric field of 972 kV/cm and at a frequency of 1 kHz, and the values decreased with increasing measurement frequency to 63 µC/cm2 and 679 kV/cm at 10 kHz, respectively. Also, after 1.44 × 1010 cycles, a better fatigue endurance was observed in the BLFZO thin film, which was 90% of its initial value. We also confirmed that the remnant polarization (2 P r ) and the coercive electric field (2 E c ) were fairly saturated above a measurement frequency of 15 kHz for the BLFZO thin film.

Optical and electrical properties of transparent conducting B-doped ZnO thin films prepared by various deposition methods

Energy Technology Data Exchange (ETDEWEB)

Nomoto, Jun-ichi; Miyata, Toshihiro; Minami, Tadatsugu [Optoelectronic Device System R and D Center, Kanazawa Institute of Technology, 7-1 Ohgigaoka, Nonoichi, Ishikawa 921-8501 (Japan)

2011-07-15

B-doped ZnO (BZO) thin films were prepared with various thicknesses up to about 500 nm on glass substrates at 200 deg. C by dc or rf magnetron sputtering deposition, pulsed laser deposition (PLD), and vacuum arc plasma evaporation (VAPE) methods. Resistivities of 4-6 x 10{sup -4}{Omega} cm were obtained in BZO thin films prepared with a B content [B/(B + Zn) atomic ratio] around 1 at. % by PLD and VAPE methods: Hall mobilities above 40 cm{sup 2}/Vs and carrier concentrations on the order of 10{sup 20} cm{sup -3}. All 500-nm-thick-BZO thin films prepared with a resistivity on the order of 10{sup -3}-10{sup -4}{Omega} cm exhibited an averaged transmittance above 80% in the wavelength range of 400-1100 nm. The resistivity in BZO thin films prepared with a thickness below about 500 nm was found to increase over time with exposure to various high humidity environments. In heat-resistance tests, the resistivity stability of BZO thin films was found to be nearly equal to that of Ga-doped ZnO thin films, so these films were judged suitable for use as a transparent electrode for thin-film solar cells.

A high power ZnO thin film piezoelectric generator

Science.gov (United States)

Qin, Weiwei; Li, Tao; Li, Yutong; Qiu, Junwen; Ma, Xianjun; Chen, Xiaoqiang; Hu, Xuefeng; Zhang, Wei

2016-02-01

A highly efficient and large area piezoelectric ZnO thin film nanogenerator (NG) was fabricated. The ZnO thin film was deposited onto a Si substrate by pulsed laser ablation at a substrate temperature of 500 °C. The deposited ZnO film exhibited a preferred c-axis orientation and a high piezoelectric value of 49.7 pm/V characterized using Piezoelectric Force Microscopy (PFM). Thin films of ZnO were patterned into rectangular power sources with dimensions of 0.5 × 0.5 cm2 with metallic top and bottom electrodes constructed via conventional semiconductor lithographic patterning processes. The NG units were subjected to periodic bending/unbending motions produced by mechanical impingement at a fixed frequency of 100 Hz at a pressure of 0.4 kg/cm2. The output electrical voltage, current density, and power density generated by one ZnO NG were recorded. Values of ∼95 mV, 35 μA cm-2 and 5.1 mW cm-2 were recorded. The level of power density is typical to that produced by a PZT NG on a flexible substrate. Higher energy NG sources can be easily created by adding more power units either in parallel or in series. The thin film ZnO NG technique is highly adaptable with current semiconductor processes, and as such, is easily integrated with signal collecting circuits that are compatible with mass production. A typical application would be using the power harvested from irregular human foot motions to either to operate blue LEDs directly or to drive a sensor network node in mille-power level without any external electric source and circuits.

Velocities of dislocation groups in very thin neutron-irradiated copper single crystals measured by slip line cinematography

International Nuclear Information System (INIS)

Potthoff, H.H.

1983-01-01

Slip line development on very thin flat single crystals of neutron-irradiated Cu (thickness down to only 15 to 20 μm, orientation for single glide, yield region, room temperature) is recorded by high-speed cinematography during tensile deformation. In such very thin crystals glide dislocations on the slip plane must be arranged in a rather simple way. Drops in tensile load occuring during initiation of single slip lines at the Lueders band front indicate that in the beginning of a slip line development dislocation groups traverse the whole glide plane in very short times. Evaluating the data measured for the slip line growth v/sub s/ >= 10 cm/s is found for screw dislocations and v/sub e/ >= v/sub s/ for edge dislocations. For later stages on thin crystals and for all stages on thick crystals (>= several 100 μm) slip line development is much slower and slip line show many cross slip events which then appear to control the mean velocity of the dislocations. (author)

Enhancement of the electrical properties of (Eu,Zn) co-doped BiFeO3 thin films prepared by using chemical solution deposition

Science.gov (United States)

Kim, Youn-Jang; Kim, Jin Won; Kim, Hae Jin; Kim, Sang Su

2013-04-01

We prepared pure BiFeO3 (BFO) and (Bi0.9Eu0.1)(Fe0.975Zn0.025)O3-δ (BEFZO) thin films on Pt(111)/Ti/SiO2/Si(100) substrates by using a chemical solution deposition method. Improved electrical properties were observed in the co-doped BEFZO thin film. The leakage current density of the BEFZO thin film was three orders of magnitude lower than that of the pure BFO, 3.93 × 10-6 A/cm2 at 100 kV/cm. The remnant polarization (2 P r ) and the coercive electric field (2 E c ) of the BEFZO thin film were 42 µC/cm2 and 898 kV/cm at an applied electric field of 1000 kV/cm and at a frequency of 1 kHz and the values decreased with increasing measurement frequency to 18 µC/cm2 and 866 kV/cm at 10 kHz, respectively. Also, the fatigue endurances were evaluated at peak voltages of 8-10 V after 1.44 × 1010 cycles in the BEFZO thin films and were 70 ˜ 90% of the initial values. We also confirmed that the 2 P r was fairly saturated at measurement frequency about 30 kHz for the BEFZO thin film.

Properties of antimony doped ZnO thin films deposited by spray pyrolysis technique

Energy Technology Data Exchange (ETDEWEB)

Sadananda Kumar, N., E-mail: sadanthara@gmail.com; Bangera, Kasturi V.; Shivakumar, G. K. [National Institute of Technology Karnataka, Surathkal, Thin Films Laboratory, Department of Physics (India)

2015-07-15

Antimony (Sb) doped zinc oxide (ZnO) thin films were deposited on the glass substrate at 450°C using spray pyrolysis technique. Effect of Sb doping on surface morphology structural, optical and electrical properties were studied. X-ray diffraction (XRD) analysis showed that both the undoped and doped ZnO thin films are polycrystalline in nature with (101) preferred orientation. SEM analysis showed a change in surface morphology of Sb doped ZnO thin films. Doping results in a marked increase in conductivity without affecting the transmittance of the films. ZnO films prepared with 3 at % Sb shows the lowest resistivity of 0.185 Ohm cm with a Hall mobility of 54.05 cm{sup 2} V{sup –1} s{sup –1}, and a hole concentration of 6.25 × 10{sup 17} cm{sup –3}.

Preparation and properties of KCl-doped Cu2O thin film by electrodeposition

International Nuclear Information System (INIS)

Yu, Xiaojiao; Li, Xinming; Zheng, Gang; Wei, Yuchen; Zhang, Ama; Yao, Binghua

2013-01-01

With the indium tin oxide-coated glass as working electrode, cuprous oxide thin film is fabricated by means of electrodeposition. The effects of KCl doped and annealing treatment upon Cu 2 O thin film morphology, surface resistivity, open-circuit voltage, electric conduction types and visible light response are studied. The research results indicate that KCl doped has a great effect upon Cu 2 O crystal morphology, thus, making Cu 2 O thin film surface resistivity drop, and the open-circuit voltage increase and that electric conduction types are transformed from p type into n type, and the visible light (400–500 nm) absorption rate is slightly reduced. Annealing treatment can obviously decrease Cu 2 O thin film surface resistivity and improve its open-circuit voltage. When KCl concentration in electrolytic solution reaches 7 mmol/L, Cu 2 O thin film morphology can be changed from the dendritic crystal into the cubic crystal and Cu 2 O thin film surface resistivity decreases from the initial 2.5 × 10 6 Ω cm to 8.5 × 10 4 Ω cm. After annealing treatment at 320 °C for 30 min, the surface resistivity decreases to 8.5 × 10 2 Ω cm, and the open-circuit voltage increases from the initial 3.1 mV to 79.2 mV.

CrN thin films prepared by reactive DC magnetron sputtering for symmetric supercapacitors

KAUST Repository

Wei, Binbin

2016-12-29

Supercapacitors have been becoming indispensable energy storage devices in micro-electromechanical systems and have been widely studied over the past few decades. Transition metal nitrides with excellent electrical conductivity and superior cycling stability are promising candidates as supercapacitor electrode materials. In this work, we report the fabrication of CrN thin films using reactive DC magnetron sputtering and further their applications for symmetric supercapacitors for the first time. The CrN thin film electrodes fabricated under the deposition pressure of 3.5 Pa show an areal specific capacitance of 12.8 mF cm at 1.0 mA cm and high cycling stability with 92.1% capacitance retention after 20 000 cycles in a 0.5 M HSO electrolyte. Furthermore, our developed CrN//CrN symmetric supercapacitor can deliver a high energy density of 8.2 mW h cm at the power density of 0.7 W cm along with outstanding cycling stability. Thus, the CrN thin films have great potential for application in supercapacitors and other energy storage systems.

4-CM2 CuInGaSe2 based solar cells

International Nuclear Information System (INIS)

Devaney, W.E.; Stewart, J.M.; Chen, W.S.

1990-01-01

This paper reports that polycrystalline thin-film solar cells with the structure ZnO/CdZnS/CuInGaSe 2 have been fabricated with larger single cell areas than have been previously reported. A cell of area 4-cm 2 has been made with an Am1.5, 100 mW/cm 2 total area conversion efficiency of (11.1% 912.0% active area) and AMO conversion efficiency of 10.0% (10.9% active area). The CuInGaSe 2 layer had a gallium to indium ratio of 0.26:0.74 with a band gap of approximately 1.15 eV. The cells use an isolated tab design for the negative (grid) contact, demonstrating the ability to pattern the semiconductor layers. Such CuInGaSe 2 based cells may be suitable both for large area terrestrial applications and for single-junction space cell applications

Room temperature ferromagnetism in undoped and Ni doped In{sub 2}O{sub 3} thin films

Energy Technology Data Exchange (ETDEWEB)

Krishna, N. Sai; Kaleemulla, S., E-mail: skaleemulla@gmail.com; Rao, N. Madhusudhana; Krishnamoorthi, C.; Begam, M. Rigana [Thin Films Laboratory, School of Advanced Sciences, VIT University, Vellore – 632014 (India); Amarendra, G. [Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam – 603102 (India); UGC-DAE-CSR, Kalpakkam Node, Kokilamedu-603104 (India)

2015-06-24

Undoped and Ni (5 at.%) doped In{sub 2}O{sub 3} thin films were deposited on glass substrate using electron beam evaporation technique and Ni doped In{sub 2}O{sub 3} thin films were annealed at 450 oC. A systematic study was carried out on the structural, chemical and magnetic properties of the as deposited and annealed thin films. X-ray diffraction analysis revealed that all the films were cubic in structure and exhibied ferromagnetism at room temperature. The undoped In{sub 2}O{sub 3} thin films exhibited a saturation magnetization of 24.01 emu/cm3. Ni doped In{sub 2}O{sub 3} thin films annealed at 450 oC showed a saturation magnetization of 53.81 emu/cm3.

Solid phase epitaxial growth of high mobility La:BaSnO_3 thin films co-doped with interstitial hydrogen

International Nuclear Information System (INIS)

Niedermeier, Christian A.; Rhode, Sneha; Fearn, Sarah; Moram, Michelle A.; Ide, Keisuke; Hiramatsu, Hidenori; Hosono, Hideo; Kamiya, Toshio

2016-01-01

This work presents the solid phase epitaxial growth of high mobility La:BaSnO_3 thin films on SrTiO_3 single crystal substrates by crystallization through thermal annealing of nanocrystalline thin films prepared by pulsed laser deposition at room temperature. The La:BaSnO_3 thin films show high epitaxial quality and Hall mobilities up to 26 ± 1 cm"2/Vs. Secondary ion mass spectroscopy is used to determine the La concentration profile in the La:BaSnO_3 thin films, and a 9%–16% La doping activation efficiency is obtained. An investigation of H doping to BaSnO_3 thin films is presented employing H plasma treatment at room temperature. Carrier concentrations in previously insulating BaSnO_3 thin films were increased to 3 × 10"1"9" cm"−"3 and in La:BaSnO_3 thin films from 6 × 10"1"9" cm"−"3 to 1.5 × 10"2"0" cm"−"3, supporting a theoretical prediction that interstitial H serves as an excellent n-type dopant. An analysis of the free electron absorption by infrared spectroscopy yields a small (H,La):BaSnO_3 electron effective mass of 0.27 ± 0.05 m_0 and an optical mobility of 26 ± 7 cm"2/Vs. As compared to La:BaSnO_3 single crystals, the smaller electron mobility in epitaxial thin films grown on SrTiO_3 substrates is ascribed to threading dislocations as observed in high resolution transmission electron micrographs.

Studies of cosmic ray events in ATLAS sTGC muon chamber prototypes

CERN Document Server

AUTHOR|(CDS)2097847; Warburton, Andreas

Four years after its first long shutdown in 2015, the Large Hadron Collider (LHC) will be shut down once more for a luminosity upgrade. During that time, the ATLAS detector on the LHC ring will also follow an upgrade program, one upgrade being the replacement of the Small Muon Wheels for a New Small Wheel containing small-strip Thin Gap Chambers (sTGCs). The sTGCs built in Canada will be tested at McGill University before their installation in ATLAS. A testing facility has been constructed and a 40 × 60 cm^2 sTGC prototype has been used to deliver preliminary measurements from cosmic rays. This thesis will present the development of a robust tracking algorithm which can handle extra clusters and multiple tracks in an sTGC detector. This algorithm also categorizes events based on their number of clusters and tracks. By modifying the trigger time window of the sTGC prototype, the evolution of the distribution of events over this categorization is shown.

Novel technique of making thin target foil of high density material via rolling method

Science.gov (United States)

Gupta, C. K.; Rohilla, Aman; Singh, R. P.; Singh, Gurjot; Chamoli, S. K.

2018-05-01

The conventional rolling method fails to yield good quality thin foils of thicknesses less than 2 mg/cm2 for high density materials with Z ≥ 70 (e.g. gold, lead). A special and improved technique has been developed to obtain such low thickness good quality gold foils by rolling method. Using this technique thin gold foils of thickness in the range of 0.850-2.5 mg/cm2 were obtained in the present work. By making use of alcohol during rolling, foils of thickness 1 mg/cm2 can be obtained in shorter time with less effort.

AZO Thin Films by Sol-Gel Process for Integrated Optics

Directory of Open Access Journals (Sweden)

Azzedine Boudrioua

2013-07-01

Full Text Available Undoped and aluminum-doped zinc oxide (AZO thin films are prepared by the sol-gel process. Zinc acetate dihydrate, ethanol, and monoethanolamine are used as precursor, solvent, and stabilizer, respectively. In the case of AZO, aluminum nitrate nonahydrate is added to the precursor solution with an atomic percentage equal to 1 and 2 at.% Al. The multi thin layers are deposited by spin-coating onto glass substrates, and are transformed into ZnO upon annealing at 550 °C. Films display a strong preferential orientation, with high values for the Texture Coefficients (TC of the (002 direction (TC(002 ≈ 3. The structural, morphological, and optical properties of the thin films as a function of aluminum content have been investigated using X-Ray Diffraction (XRD, Atomic Force Microscopy (AFM, and Scanning Electronic Microscopy (SEM. Waveguiding properties of the thin films have been also studied using m-lines spectroscopy. The results indicate that the films are monomodes at 632.8 nm with optical propagation optical losses estimated around 1.6 decibel per cm (dB/cm.

Preparation and properties of KCl-doped Cu{sub 2}O thin film by electrodeposition

Energy Technology Data Exchange (ETDEWEB)

Yu, Xiaojiao, E-mail: yxjw@xaut.edu.cn [Xi’an University of Technology, Xi’an 710048 (China); Li, Xinming [Xi’an University of Technology, Xi’an 710048 (China); Zheng, Gang [Xi’an University of Technology, Xi’an 710048 (China); Northwestern Polytechnical University, Xi’an 710072 (China); Wei, Yuchen [The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (China); Zhang, Ama; Yao, Binghua [Xi’an University of Technology, Xi’an 710048 (China)

2013-04-01

With the indium tin oxide-coated glass as working electrode, cuprous oxide thin film is fabricated by means of electrodeposition. The effects of KCl doped and annealing treatment upon Cu{sub 2}O thin film morphology, surface resistivity, open-circuit voltage, electric conduction types and visible light response are studied. The research results indicate that KCl doped has a great effect upon Cu{sub 2}O crystal morphology, thus, making Cu{sub 2}O thin film surface resistivity drop, and the open-circuit voltage increase and that electric conduction types are transformed from p type into n type, and the visible light (400–500 nm) absorption rate is slightly reduced. Annealing treatment can obviously decrease Cu{sub 2}O thin film surface resistivity and improve its open-circuit voltage. When KCl concentration in electrolytic solution reaches 7 mmol/L, Cu{sub 2}O thin film morphology can be changed from the dendritic crystal into the cubic crystal and Cu{sub 2}O thin film surface resistivity decreases from the initial 2.5 × 10{sup 6} Ω cm to 8.5 × 10{sup 4} Ω cm. After annealing treatment at 320 °C for 30 min, the surface resistivity decreases to 8.5 × 10{sup 2} Ω cm, and the open-circuit voltage increases from the initial 3.1 mV to 79.2 mV.

Spray pyrolyzed Cu2SnS3 thin films for photovoltaic application

Science.gov (United States)

Patel, Biren; Waldiya, Manmohansingh; Pati, Ranjan K.; Mukhopadhyay, Indrajit; Ray, Abhijit

2018-05-01

We report the fabrication of Cu2SnS3 (CTS) thin films by a non-vacuum and low cost spray pyrolysis technique. Annealing of the as-deposited film in the sulphur atmosphere produces highly stoichiometric, granular and crystalline CTS phase. The CTS thin films shows direct optical band gap of 1.58 eV with high absorption coefficient of 105 cm-1. Hall measurement shows the carrier concentration of the order of 1021 cm-3 and a favourable resistivity of 10-3 Ω cm. A solar cell architecture of Glass/FTO/CTS/CdS/Al:ZnO/Al was fabricated and its current-voltage characteristic shows an open circuit voltage, short circuit current density and fill-factor of 12.6 mV, 20.2 µA/cm2 and 26% respectively. A further improvement in the solar cell parameters is underway.

Estimation of radioactive contaminants in Cm242 and Cm244 isotopic fuels

International Nuclear Information System (INIS)

Terent'ev, V.P.; Makarenko, A.I.

1972-01-01

The radiation properties of Cm 242 and Cm 244 preparations and the effect on them of possible contaminants are considered. One of the most important requirements for K alpha active fuels for radioisotope thermoelectric batteries is ensuring a low ionizing radiation background. In determining the effect of impurities on the radiation properties of a preparation, quantitative evaluation of certain factors is sufficient. In a Cm 242 preparation it is possible to show that Am 241 and Cm 243 are undesirable impurities. The presence of Am 241 increases the soft gamma output by 20%. The presence of Cm 243 may double the dose rate from an unshielded preparation and increase the hard gamma output 10-fold. The properties of Cm 242 preparations deteriorate when Am 243 and Cm 243 are present

YIELD OF Pinus taeda L. IN THINNED STAND IN THE CAMPOS DE CIMA DA SERRA REGION, RIO GRANDE DO SUL.

Directory of Open Access Journals (Sweden)

Luiz Ernesto Grillo Elesbão

2011-03-01

Full Text Available This work was carried out with the objective of studying the yield of Pinus taeda L., planted in an initial spacing of 3 x 2 m, located in Canela, Rio Grande do Sul state. The amostral population was submitted to one and two selective thinning, beyond a control sample, without thinning. The selective low thinning was conducted with reduction of the basal area to levels of 28 m2/ha. At age 17, the total yield of the control sample, without thinning, was 886.3 m3ha-1; with one thinning at age 11 the yield was 756.6 m3ha-1, resulting in losses of yield of 14.6% compared to the control; with two selective at ages 11 and 15, the yield was 732.9 m3ha-1, resulting in losses of yield in relation with the control sample, without thinning, of 17.3%. The selective thinning allowed a significant gain in diameter, up to age 17, with the execution of a selective thinning at age 11 an average diameter of 33.4 cm; with two selective thinning at ages 11 and 15 an average diameter of 33.5 cm; and an average diameter of 24.3 cm in the control sample, without thinning.

Confirmed results of the 248Cm(48Ca,4n)292116 experiment

International Nuclear Information System (INIS)

Patin, J B; Moody, K J; Stoyer, M A; Wild, J F; Shaughnessy, D A; Stoyer, N J

2003-01-01

The results of a detailed analysis performed on the data obtained in the 248 Cm( 48 Ca,4n) 292 116 reaction is presented. This analysis is independent of the original data analysis performed in Dubna in which three separate decay chains were found. Each decay chain began with an evaporation residue followed by three α decays and ended in a spontaneous fission event, all correlated in time and position. The analysis presented confirms that the three events are present in the data. A summary of the three events will be given as well as a description of the analysis performed

Structural and magnetic properties of pure and Cu doped In{sub 2}O{sub 3} thin films

Energy Technology Data Exchange (ETDEWEB)

Krishna, N. Sai; Kaleemulla, S., E-mail: skaleemulla@gmail.com; Rao, N. Madhusudhana; Krishnamoorthi, C.; Begam, M. Rigana [Thin Films Laboratory, School of Advanced Sciences, VIT University, Vellore – 632014 (India); Amarendra, G. [Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam –603102 (India); UGC-DAE-CSR, Kalpakkam Node, Kokilamedu-603104 (India)

2015-06-24

Pure and Cu (7 at.%) doped In{sub 2}O{sub 3} thin films were prepared using an electron beam evaporation technique. A systematic study was carried out on the structural, chemical and magnetic properties of the thin films. X-ray diffraction analysis revealed that all the films were cubic in structure. The pure and Cu doped In{sub 2}O{sub 3} thin films showed ferromagnetism at room temperature. The Cu doped In{sub 2}O{sub 3} thin films showed the saturation magnetization, coercivity and retentivity of 38.71 emu/cm{sup 3}, 245 G and 5.54 emu/cm{sup 3}, respectively.

Physicochemical, thin layer and gas-liquid chromatographic ...

African Journals Online (AJOL)

DELL

2012-05-22

May 22, 2012 ... PEG (3 m × 3 mm I. D.) was used for gas chromatography. Physicochemical analysis ... subjected to thin layer chromatography on plates (20 × 20 cm) having 0.25 mm thick silica gel ..... Headspace solid- phase microextraction ...

Enhanced electrical properties in bilayered ferroelectric thin films

Science.gov (United States)

Zhang, Hao; Long, WeiJie; Chen, YaQing; Guo, DongJie

2013-03-01

Sr2Bi4Ti5O18 (SBTi) single layered and Sr2Bi4Ti5O18/Pb(Zr0.53Ti0.47)O3 (SBTi/PZT) bilayered thin films have been prepared on Pt/TiO2/SiO2/Si substrates by pulsed-laser deposition (PLD). The related structural characterizations and electrical properties have been comparatively investigated. X-ray diffraction reveals that both films have crystallized into perovskite phases and scanning electron microscopy shows the sharp interfaces. Both films show well-saturated ferroelectric hysteresis loops, however, compared with the single layered SBTi films, the SBTi/PZT bilayered films have significantly increased remnant polarization ( P r) and decreased coercive field ( E c), with the applied field of 260 kV/cm. The measured P r and E c of SBTi and SBTi/PZT films were 7.9 μC/cm2, 88.1 kV/cm and 13.0 μC/cm2, 51.2 kV/cm, respectively. In addition, both films showed good fatigue-free characteristics, the switchable polarization decreased by 9% and 11% of the initial values after 2.2×109 switching cycles for the SBTi single layered films and the SBTi/PZT bilayered films, respectively. Our results may provide some guidelines for further optimization of multilayered ferroelectric thin films.

Stability of tetraphenyl butadiene thin films in liquid xenon

International Nuclear Information System (INIS)

Sanguino, P.; Balau, F.; Botelho do Rego, A.M.; Pereira, A.; Chepel, V.

2016-01-01

Tetraphenyl butadiene (TPB) is widely used in particle detectors as a wavelength shifter. In this work we studied the stability of TPB thin films when immersed in liquid xenon (LXe). The thin films were deposited on glass and quartz substrates by thermal evaporation. Morphological and chemical surface properties were monitored before and after immersion into LXe by scanning electron microscopy and X-ray photoelectron spectroscopy. No appreciable changes have been detected with these two methods. Grain size and surface chemical composition were found to be identical before and after submersion into LXe. However, the film thickness, measured via optical transmission in the ultraviolet–visible wavelength regions, decreased by 1.6 μg/cm 2 (24%) after immersion in LXe during 20 h. These results suggest the necessity of using a protective thin film over the Tetraphenyl butadiene when used as a wavelength shifter in LXe particle detectors. - Highlights: • Stability of tetraphenyl butadiene (TPB) thin films immersed in liquid xenon (LXe). • Thermally evaporated TPB thin films were immersed in LXe for 20 h. • Film morphology and chemical surface properties remained unchanged. • Surface density of the films decreased by 1.6 μg/cm 2 (24%) after immersion in LXe. • For using in LXe particle detectors, TPB films should be protected with a coating.

Piezoelectric Response Evaluation of ZnO Thin Film Prepared by RF Magnetron Sputtering

Directory of Open Access Journals (Sweden)

Cheng Da-Long

2017-01-01

Full Text Available The most important parameter of piezoelectric materials is piezoelectric coefficient (d33. In this study, the piezoelectric ZnO thin films were deposited on the SiNx/Si substrate. The 4 inches substrate is diced into 8 cm× 8 cm piece. During the deposition process, a zinc target (99.999 wt% of 2 inches diameter was used. The vertical distance between the target and the substrate holder was fixed at 5 cm. The piezoelectric response of zinc oxide (ZnO thin films were obtained by using a direct measurement system. The system adopts a mini impact tip to generate an impulsive force and read out the piezoelectric signals immediately. Experimentally, a servo motor is used to produce a fixed quantity of force, for giving an impact against to the piezoelectric film. The ZnO thin films were deposited using the reactive radio frequency (RF magnetron sputtering method. The electric charges should be generated because of the material’s extrusion. This phenomenon was investigated through the oscilloscope by one shot trigger. It was apparent that all ZnO films exhibit piezoelectric responses evaluated by our measurement system, however, its exhibit a significant discrepancy. The piezoelectric responses of ZnO thin film at various deposition positions were measured and the crystal structures of the sputtering pressure were also discussed. The crystalline characteristics of ZnO thin films are investigated through the XRD and SEM. The results show the ZnO thin film exhibits good crystalline pattern and surface morphology with controlled sputtering condition. The ZnO thin films sputtered using 2 inches target present various piezoelectric responses. With the exactly related position, a best piezoelectric response of ZnO thin film can be achieved.

Electronic excitation induced modification in fullerene C{sub 70} thin films

Energy Technology Data Exchange (ETDEWEB)

Sharma, Pooja [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); Banerjee, M.K. [Department of Metallurgical & Materials Engineering, 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 - PG College, Bijnor 246701, UP (India); Kaushik, R. [Department of Physics and Materials Research Centre, Malaviya National Institute of Technology, Jaipur 302017 (India); Department of Physics, Shri K.K. Jain - PG College, Khatauli, UP (India); Singh, F. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India)

2016-07-15

Fullerene C{sub 70} thin films were deposited by resistive heating on glass substrates and the thickness were approximated to be 150 nm. The effect of energy deposition by 55 MeV Si ions on the optical and structural properties of the prepared thin film samples is investigated. The samples were irradiated with 55 MeV Si ions within fluence range from 1 × 10{sup 12} to 3 × 10{sup 13} ions/cm{sup 2}. For optical studies, the pristine and the Si ion irradiated samples are examined by UV–visible absorption spectroscopy and Raman spectroscopy. UV–visible absorption studies reveal that the absorption peaks of irradiated samples decrease with a decrease in the band gap of the thin films. The damage cross-section (σ) and radius of damaged cylindrical zone (r) are determined as ∼0.6 × 10{sup −13} cm{sup 2} and ∼1.41 nm, respectively from the Raman spectra. Raman studies also suggest that at higher fluence (up to 3 × 10{sup 13} ions/cm{sup 2}), the damage caused by the SHI results in partial amorphization of fullerene C{sub 70} thin film. Modification in the surface properties has been investigated by atomic force microscopy; it has revealed that the roughness decreases and average particle size increases with the increase in fluences.

Magnetic hysteresis of cerium doped bismuth ferrite thin films

International Nuclear Information System (INIS)

Gupta, Surbhi; Tomar, Monika; Gupta, Vinay

2015-01-01

The influence of Cerium doping on the structural and magnetic properties of BiFeO 3 thin films have been investigated. Rietveld refinement of X-ray diffraction data and successive de-convolution of Raman scattering spectra of Bi 1−x Ce x FeO 3 (BCFO) thin films with x=0–0.20 reflect the single phase rhombohedral (R3c) formation for x<0.08, whereas concentration-driven gradual structural phase transition from rhombohedral (R3c) to partial tetragonal (P4mm) phase follows for x≥0.08. All low wavenumber Raman modes (<300 cm −1 ) showed a noticeable shift towards higher wavenumber with increase in doping concentration, except Raman E-1 mode (71 cm −1 ), shows a minor shift. Sudden evolution of Raman mode at 668 cm −1 , manifested as A 1 -tetragonal mode, accompanied by the shift to higher wavenumber with increase in doping concentration (x) affirm partial structural phase transition. Anomalous wasp waist shaped (M–H) hysteresis curves with improved saturation magnetization (M s ) for BCFO thin films is attributed to antiferromagnetic interaction/hybridization between Ce 4f and Fe 3d electronic states. The contribution of both hard and soft phase to the total coercivity is calculated. Polycrystalline Bi 0.88 Ce 0.12 FeO 3 thin film found to exhibit better magnetic properties with M s =15.9 emu/g without any impure phase. - Highlights: • Synthesis of single phase Bi 1−x Ce x FeO 3 thin films with (x=0–0.2) on cost effective corning glass and silicon substrates using CSD technique. • Structural modification studies using Rietveld refinement of XRD and de-convolution of Raman spectra revealed partial phase transition from rhombohedral (R3c) to tetragonal (P4mm) phase. • Possible reasons for origin of pinched magnetic behavior of BCFO thin films are identified. • Contribution of both hard and soft magnetic phase in coercivity of BCFO thin films is calculated and practical applications of such materials exhibiting pinching behavior are conferred

Magnetic hysteresis of cerium doped bismuth ferrite thin films

Energy Technology Data Exchange (ETDEWEB)

Gupta, Surbhi [Department of Physics and Astrophysics, University of Delhi (India); Tomar, Monika [Physics Department, Miranda House, University of Delhi (India); Gupta, Vinay, E-mail: drguptavinay@gmail.com [Department of Physics and Astrophysics, University of Delhi (India)

2015-03-15

The influence of Cerium doping on the structural and magnetic properties of BiFeO{sub 3} thin films have been investigated. Rietveld refinement of X-ray diffraction data and successive de-convolution of Raman scattering spectra of Bi{sub 1−x}Ce{sub x}FeO{sub 3} (BCFO) thin films with x=0–0.20 reflect the single phase rhombohedral (R3c) formation for x<0.08, whereas concentration-driven gradual structural phase transition from rhombohedral (R3c) to partial tetragonal (P4mm) phase follows for x≥0.08. All low wavenumber Raman modes (<300 cm{sup −1}) showed a noticeable shift towards higher wavenumber with increase in doping concentration, except Raman E-1 mode (71 cm{sup −1}), shows a minor shift. Sudden evolution of Raman mode at 668 cm{sup −1}, manifested as A{sub 1}-tetragonal mode, accompanied by the shift to higher wavenumber with increase in doping concentration (x) affirm partial structural phase transition. Anomalous wasp waist shaped (M–H) hysteresis curves with improved saturation magnetization (M{sub s}) for BCFO thin films is attributed to antiferromagnetic interaction/hybridization between Ce 4f and Fe 3d electronic states. The contribution of both hard and soft phase to the total coercivity is calculated. Polycrystalline Bi{sub 0.88}Ce{sub 0.12}FeO{sub 3} thin film found to exhibit better magnetic properties with M{sub s}=15.9 emu/g without any impure phase. - Highlights: • Synthesis of single phase Bi{sub 1−x}Ce{sub x}FeO{sub 3} thin films with (x=0–0.2) on cost effective corning glass and silicon substrates using CSD technique. • Structural modification studies using Rietveld refinement of XRD and de-convolution of Raman spectra revealed partial phase transition from rhombohedral (R3c) to tetragonal (P4mm) phase. • Possible reasons for origin of pinched magnetic behavior of BCFO thin films are identified. • Contribution of both hard and soft magnetic phase in coercivity of BCFO thin films is calculated and practical

Low-cost flexible thin-film detector for medical dosimetry applications.

Science.gov (United States)

Zygmanski, P; Abkai, C; Han, Z; Shulevich, Y; Menichelli, D; Hesser, J

2014-03-06

The purpose of this study is to characterize dosimetric properties of thin film photovoltaic sensors as a platform for development of prototype dose verification equipment in radiotherapy. Towards this goal, flexible thin-film sensors of dose with embedded data acquisition electronics and wireless data transmission are prototyped and tested in kV and MV photon beams. Fundamental dosimetric properties are determined in view of a specific application to dose verification in multiple planes or curved surfaces inside a phantom. Uniqueness of the new thin-film sensors consists in their mechanical properties, low-power operation, and low-cost. They are thinner and more flexible than dosimetric films. In principle, each thin-film sensor can be fabricated in any size (mm² - cm² areas) and shape. Individual sensors can be put together in an array of sensors spreading over large areas and yet being light. Photovoltaic mode of charge collection (of electrons and holes) does not require external electric field applied to the sensor, and this implies simplicity of data acquisition electronics and low power operation. The prototype device used for testing consists of several thin film dose sensors, each of about 1.5 cm × 5 cm area, connected to simple readout electronics. Sensitivity of the sensors is determined per unit area and compared to EPID sensitivity, as well as other standard photodiodes. Each sensor independently measures dose and is based on commercially available flexible thin-film aSi photodiodes. Readout electronics consists of an ultra low-power microcontroller, radio frequency transmitter, and a low-noise amplification circuit implemented on a flexible printed circuit board. Detector output is digitized and transmitted wirelessly to an external host computer where it is integrated and processed. A megavoltage medical linear accelerator (Varian Tx) equipped with kilovoltage online imaging system and a Cobalt source are used to irradiate different thin

Highly polarized single-c-domain single-crystal Pb(Mn,Nb)O(3)-PZT thin films.

Science.gov (United States)

Wasa, Kiyotaka; Adachi, Hideaki; Nishida, Ken; Yamamoto, Takashi; Matsushima, Tomoaki; Kanno, Isaku; Kotera, Hidetoshi

2012-01-01

In-plane unstrained single-c-domain/single-crystal thin films of PZT-based ternary ferroelectric perovskite, ξPb(Mn,Nb)O3-(1 - ξ)PZT, were grown on SrRuO(3)/Pt/MgO substrates using magnetron sputtering followed by quenching. The sputtered unstrained thin films exhibit unique ferroelectric properties: high coercive field, Ec > 180 kV/cm, large remanent polarization, P(r) = 100 μC/cm(2), small relative dielectric constants, ε* = 100 to 150, high Curie temperature, Tc = ~600 °C, and bulk-like large transverse piezoelectric constants, e31,f = -12.0 C/m(2) for PZT(48/52) at ξ = 0.06. The unstrained thin films are an ideal structure to extract the bulk ferroelectric properties. Their micro-structures and ferroelectric properties are discussed in relation to the potential applications for piezoelectric MEMS. © 2012 IEEE

Flapping dynamics of a thin liquid sheet

Science.gov (United States)

Vadivukkarasan, M.; Kumaran, Dhivyaraja; Panchagnula, Mahesh; Multi-phase flow physics Group Team

2017-11-01

We attempt to delineate and describe the complete evolution of a thin soap film when air is blown through a nozzle in the normal direction. The sequence of events and its intrinsic dynamics are captured using high speed imaging. By careful observation, it was observed that multiple mechanisms occur in the same system and each event is triggered by an independent mechanism. The events include (a) flapping of a liquid sheet and pinching of the bubble, (b) onset of rupture on the liquid sheet, (c) formation of ligaments and (d) ejection of drops. From this study, it is shown that these events are predominantly governed by Kelvin-Helmholtz instability, Taylor - Culick law, Rayleigh-Taylor instability and capillary instability, respectively. The present experiments can be considered as an extension to the previous studies on soap films as well as thin flapping sheets which has direct relevance to coaxial atomizers used in aircraft applications.

Combustion synthesized indium-tin-oxide (ITO) thin film for source/drain electrodes in all solution-processed oxide thin-film transistors

International Nuclear Information System (INIS)

Tue, Phan Trong; Inoue, Satoshi; Takamura, Yuzuru; Shimoda, Tatsuya

2016-01-01

We report combustion solution synthesized (SCS) indium-tin-oxide (ITO) thin film, which is a well-known transparent conductive oxide, for source/drain (S/D) electrodes in solution-processed amorphous zirconium-indium-zinc-oxide TFT. A redox-based combustion synthetic approach is applied to ITO thin film using acetylacetone as a fuel and metal nitrate as oxidizer. The structural and electrical properties of SCS-ITO precursor solution and thin films were systematically investigated with changes in tin concentration, indium metal precursors, and annealing conditions such as temperature, time, and ambient. It was found that at optimal conditions the SCS-ITO thin film exhibited high crystalline quality, atomically smooth surface (RMS ∝ 4.1 Aa), and low electrical resistivity (4.2 x 10 -4 Ω cm). The TFT using SCS-ITO film as the S/D electrodes showed excellent electrical properties with negligible hysteresis. The obtained ''on/off'' current ratio, subthreshold swing factor, subthreshold voltage, and field-effect mobility were 5 x 10 7 , 0.43 V/decade, 0.7 V, and 2.1 cm 2 /V s, respectively. The performance and stability of the SCS-ITO TFT are comparable to those of the sputtered-ITO TFT, emphasizing that the SCS-ITO film is a promising candidate for totally solution-processed oxide TFTs. (orig.)

Investigation of the Optoelectronic Properties of Ti-doped Indium Tin Oxide Thin Film

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Nen-Wen Pu

2015-09-01

Full Text Available : In this study, direct-current magnetron sputtering was used to fabricate Ti-doped indium tin oxide (ITO thin films. The sputtering power during the 350-nm-thick thin-film production process was fixed at 100 W with substrate temperatures increasing from room temperature to 500 °C. The Ti-doped ITO thin films exhibited superior thin-film resistivity (1.5 × 10−4 Ω/cm, carrier concentration (4.1 × 1021 cm−3, carrier mobility (10 cm2/Vs, and mean visible-light transmittance (90% at wavelengths of 400–800 nm at a deposition temperature of 400 °C. The superior carrier concentration of the Ti-doped ITO alloys (>1021 cm−3 with a high figure of merit (81.1 × 10−3 Ω−1 demonstrate the pronounced contribution of Ti doping, indicating their high suitability for application in optoelectronic devices.

Highly-efficient, flexible piezoelectric PZT thin film nanogenerator on plastic substrates.

Science.gov (United States)

Park, Kwi-Il; Son, Jung Hwan; Hwang, Geon-Tae; Jeong, Chang Kyu; Ryu, Jungho; Koo, Min; Choi, Insung; Lee, Seung Hyun; Byun, Myunghwan; Wang, Zhong Lin; Lee, Keon Jae

2014-04-23

A highly-efficient, flexible piezoelectric PZT thin film nanogenerator is demonstrated using a laser lift-off (LLO) process. The PZT thin film nanogenerator harvests the highest output performance of ∼200 V and ∼150 μA·cm(-2) from regular bending motions. Furthermore, power sources generated from a PZT thin film nanogenerator, driven by slight human finger bending motions, successfully operate over 100 LEDs. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Structure and magnetic properties of Fe doped In{sub 2}O{sub 3} thin films prepared by electron beam evaporation

Energy Technology Data Exchange (ETDEWEB)

Krishna, N. Sai; Kaleemulla, S., E-mail: skaleemulla@gmail.com; Rao, N. Madhusudhana; Krishnamoorthi, C.; Begam, M. Rigana [Thin Films Laboratory, School of Advanced Sciences, VIT University, Vellore – 632014 (India); Amarendra, G. [Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam – 603102 (India); UGC-DAE-CSR, Kalpakkam Node, Kokilamedu, Tamilnadu -603104 (India)

2015-06-24

Pure and Fe (7 at.%) doped In{sub 2}O{sub 3} thin films were grown onto the glass substrates by electron beam evaporation technique. The structural and magnetic properties of the pure and Fe doped In{sub 2}O{sub 3} thin films have been studied. The undoped and Fe doped In{sub 2}O{sub 3} thin films shown ferromagnetic property at room temperature. A magnetization of 24 emu/cm{sup 3} was observed for pure In{sub 2}O{sub 3} thin films. The magnetization of 38.23 emu/cm{sup 3} was observed for the Fe (7 at.%) doped In{sub 2}O{sub 3} thin films.

Effects of thinning intensities on soil infiltration and water storage capacity in a Chinese pine-oak mixed forest.

Science.gov (United States)

Chen, Lili; Yuan, Zhiyou; Shao, Hongbo; Wang, Dexiang; Mu, Xingmin

2014-01-01

Thinning is a crucial practice in the forest ecosystem management. The soil infiltration rate and water storage capacity of pine-oak mixed forest under three different thinning intensity treatments (15%, 30%, and 60%) were studied in Qinling Mountains of China. The thinning operations had a significant influence on soil infiltration rate and water storage capacity. The soil infiltration rate and water storage capacity in different thinning treatments followed the order of control (nonthinning): soil infiltration rate and water storage capacity of pine-oak mixed forest in Qinling Mountains. The soil initial infiltration rate, stable infiltration rate, and average infiltration rate in thinning 30% treatment were significantly increased by 21.1%, 104.6%, and 60.9%, compared with the control. The soil maximal water storage capacity and noncapillary water storage capacity in thinning 30% treatment were significantly improved by 20.1% and 34.3% in contrast to the control. The soil infiltration rate and water storage capacity were significantly higher in the surface layer (0~20 cm) than in the deep layers (20~40 cm and 40~60 cm). We found that the soil property was closely related to soil infiltration rate and water storage capacity.

Improvement of physical properties of IGZO thin films prepared by excimer laser annealing of sol–gel derived precursor films

International Nuclear Information System (INIS)

Tsay, Chien-Yie; Huang, Tzu-Teng

2013-01-01

Indium gallium zinc oxide (IGZO) transparent semiconductor thin films were prepared by KrF excimer laser annealing of sol–gel derived precursor films. Each as-coated film was dried at 150 °C in air and then annealed using excimer laser irradiation. The influence of laser irradiation energy density on surface conditions, optical transmittances, and electrical properties of laser annealed IGZO thin films were investigated, and the physical properties of the excimer laser annealed (ELA) and the thermally annealed (TA) thin films were compared. Experimental results showed that two kinds of surface morphology resulted from excimer laser annealing. Irradiation with a lower energy density (≤250 mJ cm −2 ) produced wavy and irregular surfaces, while irradiation with a higher energy density (≥350 mJ cm −2 ) produced flat and dense surfaces consisting of uniform nano-sized amorphous particles. The explanation for the differences in surface features and film quality is that using laser irradiation energy to form IGZO thin films improves the film density and removes organic constituents. The dried IGZO sol–gel films irradiated with a laser energy density of 350 mJ/cm 2 had the best physical properties of all the ELA IGZO thin films. The mean resistivity of the ELA 350 thin films (4.48 × 10 3 Ω cm) was lower than that of TA thin films (1.39 × 10 4 Ω cm), and the average optical transmittance in the visible range (90.2%) of the ELA 350 thin films was slightly higher than that of TA thin films (89.7%). - Highlights: • IGZO semiconductor films were prepared by laser annealing of sol–gel derived films. • Surface roughness and resistivity of ELA samples were affected by energy density. • The ELA 350 IGZO film exhibited the best properties among all of ELA IGZO films. • Transmittance and resistivity of ELA 350 films are greater than those of TA films

Improvement of physical properties of IGZO thin films prepared by excimer laser annealing of sol–gel derived precursor films

Energy Technology Data Exchange (ETDEWEB)

Tsay, Chien-Yie, E-mail: cytsay@fcu.edu.tw; Huang, Tzu-Teng

2013-06-15

Indium gallium zinc oxide (IGZO) transparent semiconductor thin films were prepared by KrF excimer laser annealing of sol–gel derived precursor films. Each as-coated film was dried at 150 °C in air and then annealed using excimer laser irradiation. The influence of laser irradiation energy density on surface conditions, optical transmittances, and electrical properties of laser annealed IGZO thin films were investigated, and the physical properties of the excimer laser annealed (ELA) and the thermally annealed (TA) thin films were compared. Experimental results showed that two kinds of surface morphology resulted from excimer laser annealing. Irradiation with a lower energy density (≤250 mJ cm{sup −2}) produced wavy and irregular surfaces, while irradiation with a higher energy density (≥350 mJ cm{sup −2}) produced flat and dense surfaces consisting of uniform nano-sized amorphous particles. The explanation for the differences in surface features and film quality is that using laser irradiation energy to form IGZO thin films improves the film density and removes organic constituents. The dried IGZO sol–gel films irradiated with a laser energy density of 350 mJ/cm{sup 2} had the best physical properties of all the ELA IGZO thin films. The mean resistivity of the ELA 350 thin films (4.48 × 10{sup 3} Ω cm) was lower than that of TA thin films (1.39 × 10{sup 4} Ω cm), and the average optical transmittance in the visible range (90.2%) of the ELA 350 thin films was slightly higher than that of TA thin films (89.7%). - Highlights: • IGZO semiconductor films were prepared by laser annealing of sol–gel derived films. • Surface roughness and resistivity of ELA samples were affected by energy density. • The ELA 350 IGZO film exhibited the best properties among all of ELA IGZO films. • Transmittance and resistivity of ELA 350 films are greater than those of TA films.

Electrochromism and photocatalysis in dendrite structured Ti:WO3 thin films grown by sputtering

Energy Technology Data Exchange (ETDEWEB)

Karuppasamy, A., E-mail: karuppasamy@psnacet.edu.in

2015-12-30

Graphical abstract: - Highlights: • Dendrite structured Ti doped WO{sub 3} (WTO) thin films are grown by co-sputtering. • Sputtering condition influences structure and surface morphology of WTO films. • Titanium doping and annealing lead to dendritic surface structures in WTO films. • Structural, optical, electrochromic and photocatalytic properties of WTO films. • Enhanced electrochromism and photocatalysis in dendrite structured WTO thin films. - Abstract: Titanium doped tungsten oxide (Ti:WO{sub 3}) thin films with dendrite surface structures were grown by co-sputtering titanium and tungsten in Ar + O{sub 2} atmosphere. Ti:WO{sub 3} thin films were deposited at oxygen flow rates corresponding to pressures in the range 1.0 × 10{sup −3}–5.0 × 10{sup −3} mbar. Argon flow rate and sputtering power densities for titanium (2 W/cm{sup 2}) and tungsten (3 W/cm{sup 2}) were kept constant. Ti:WO{sub 3} films deposited at an oxygen pressure of 5 × 10{sup −3} mbar are found to be better electrochromic and photocatalytic. They have high optical modulation (80% at λ = 550 nm), coloration efficiency (60 cm{sup 2}/C at λ = 550 nm), electron/ion storage and removal capacity (Qc: −22.01 mC/cm{sup 2}, Qa: 17.72 mC/cm{sup 2}), reversibility (80%) and methylene blue decomposition rate (−1.38 μmol/l d). The combined effects of titanium doping, dendrite surface structures and porosity leads to significant enhancement in the electrochromic and photocatalytic properties of Ti:WO{sub 3} films.

Electrochromism and photocatalysis in dendrite structured Ti:WO3 thin films grown by sputtering

International Nuclear Information System (INIS)

Karuppasamy, A.

2015-01-01

Graphical abstract: - Highlights: • Dendrite structured Ti doped WO 3 (WTO) thin films are grown by co-sputtering. • Sputtering condition influences structure and surface morphology of WTO films. • Titanium doping and annealing lead to dendritic surface structures in WTO films. • Structural, optical, electrochromic and photocatalytic properties of WTO films. • Enhanced electrochromism and photocatalysis in dendrite structured WTO thin films. - Abstract: Titanium doped tungsten oxide (Ti:WO 3 ) thin films with dendrite surface structures were grown by co-sputtering titanium and tungsten in Ar + O 2 atmosphere. Ti:WO 3 thin films were deposited at oxygen flow rates corresponding to pressures in the range 1.0 × 10 −3 –5.0 × 10 −3 mbar. Argon flow rate and sputtering power densities for titanium (2 W/cm 2 ) and tungsten (3 W/cm 2 ) were kept constant. Ti:WO 3 films deposited at an oxygen pressure of 5 × 10 −3 mbar are found to be better electrochromic and photocatalytic. They have high optical modulation (80% at λ = 550 nm), coloration efficiency (60 cm 2 /C at λ = 550 nm), electron/ion storage and removal capacity (Qc: −22.01 mC/cm 2 , Qa: 17.72 mC/cm 2 ), reversibility (80%) and methylene blue decomposition rate (−1.38 μmol/l d). The combined effects of titanium doping, dendrite surface structures and porosity leads to significant enhancement in the electrochromic and photocatalytic properties of Ti:WO 3 films.

Nanocrystalline magnetite thin films grown by dual ion-beam sputtering

International Nuclear Information System (INIS)

Prieto, Pilar; Ruiz, Patricia; Ferrer, Isabel J.; Figuera, Juan de la; Marco, José F.

2015-01-01

Highlights: • We have grown tensile and compressive strained nanocrystalline magnetite thin films by dual ion beam sputtering. • The magnetic and thermoelectric properties can be controlled by the deposition conditions. • The magnetic anisotropy depends on the crystalline grain size. • The thermoelectric properties depend on the type of strain induced in the films. • In plane uniaxial magnetic anisotropy develops in magnetite thin films with grain sizes ⩽20 nm. - Abstract: We have explored the influence of an ion-assisted beam in the thermoelectric and magnetic properties of nanocrystalline magnetite thin films grown by ion-beam sputtering. The microstructure has been investigated by XRD. Tensile and compressive strained thin films have been obtained as a function of the parameters of the ion-assisted beam. The evolution of the in-plane magnetic anisotropy was attributed to crystalline grain size. In some films, magneto-optical Kerr effect measurements reveal the existence of uniaxial magnetic anisotropy induced by the deposition process related with a small grain size (⩽20 nm). Isotropic magnetic properties have observed in nanocrystalline magnetite thin film having larger grain sizes. The largest power factor of all the films prepared (0.47 μW/K 2 cm), obtained from a Seebeck coefficient of −80 μV/K and an electrical resistivity of 13 mΩ cm, is obtained in a nanocrystalline magnetite thin film with an expanded out-of-plane lattice and with a grain size ≈30 nm

Enhanced dielectric and electrical properties of annealed PVDF thin film

Science.gov (United States)

Arshad, A. N.; Rozana, M. D.; Wahid, M. H. M.; Mahmood, M. K. A.; Sarip, M. N.; Habibah, Z.; Rusop, M.

2018-05-01

Poly (vinylideneflouride) (PVDF) thin films were annealed at various annealing temperatures ranging from 70°C to 170°C. This study demonstrates that PVDF thin films annealed at temperature of 70°C (AN70) showed significant enhancement in their dielectric constant (14) at frequency of 1 kHz in comparison to un-annealed PVDF (UN-PVDF), dielectric constant (10) at the same measured frequency. As the annealing temperature was increased from 90°C (AN90) to 150°C (AN150), the dielectric constant value of PVDF thin films was observed to decrease gradually to 11. AN70 also revealed low tangent loss (tan δ) value at similar frequency. With respect to its resistivity properties, the values were found to increase from 1.98×104 Ω.cm to 3.24×104 Ω.cm for AN70 and UN-PVDF films respectively. The improved in dielectric constant, with low tangent loss and high resistivity value suggests that 70°C is the favorable annealing temperature for PVDF thin films. Hence, AN70 is a promising film to be utilized for application in electronic devices such as low frequency capacitor.

Ferroelectricity, Piezoelectricity, and Dielectricity of 0.06PMnN-0.94PZT(45/55 Thin Film on Silicon Substrate

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Tao Zhang

2015-01-01

Full Text Available The high piezoelectricity and high quality factor ferroelectric thin films are important for electromechanical applications especially the micro electromechanical system (MEMS. The ternary compound ferroelectric thin films 0.06Pb(Mn1/3, Nb2/3O3 + 0.94Pb(Zr0.45, Ti0.55O3 (0.06PMnN-0.94PZT(45/55 were deposited on silicon(100 substrates by RF magnetron sputtering method considering that Mn and Nb doping will improve PZT properties in this research. For comparison, nondoped PZT(45/55 films were also deposited. The results show that both of thin films show polycrystal structures with the main (111 and (101 orientations. The transverse piezoelectric coefficients are e31,eff=−4.03 C/m2 and e31,eff=-3.5 C/m2, respectively. These thin films exhibit classical ferroelectricity, in which the coercive electric field intensities are 2Ec=147.31 kV/cm and 2Ec=135.44 kV/cm, and the saturation polarization Ps=30.86 μC/cm2 and Ps=17.74 μC/cm2, and the remnant polarization Pr=20.44 μC/cm2 and Pr=9.87 μC/cm2, respectively. Moreover, the dielectric constants and loss are εr=681 and D=5% and εr=537 and D=4.3%, respectively. In conclusion, 0.06PMnN-0.94PZT(45/55 thin films act better than nondoped films, even though their dielectric constants are higher. Their excellent ferroelectricity, piezoelectricity, and high power and energy storage property, especially the easy fabrication, integration realizable, and potentially high quality factor, make this kind of thin films available for the realistic applications.

Optical Properties and Electrochemical Performance of LiFePO4 Thin Films Deposited on Transparent Current Collectors.

Science.gov (United States)

Lee, HyunSeok; Yim, Haena; Kim, Kwang-Bum; Choi, Ji-Won

2015-11-01

LiFePO4 thin film cathodes are deposited on various transparent conducting oxide thin films on glass, which are used as cathode current collectors. The XRD patterns show that the thin films have the phase of LiFePO4 with an ordered olivine structure indexed to the orthorhombic Pmna space group. LiFePO4 thin film deposited on various TCO glass substrates exhibits transmittance of about 53%. The initial specific discharge capacities of LiFePO4 thin films are 25.0 μAh/cm2 x μm on FTO, 33.0 μAh/cm2 x μm on ITO, and 13.0 μAh/cm2 x μm on AZO coated glass substrates. Interestingly, the retention capacities of LiFePO4 thin films are 76.0% on FTO, 31.2% on ITO, and 37.7% on AZO coated glass substrates at 20th cycle. The initial specific discharge capacity of the LiFePO4/FTO electrode is slightly lower, but the discharge capacities of the LiFePO4/FTO electrode relatively decrease less than those of the others such as LiFePO4/ITO and LiFePO4/AZO with cycling. The results reported here provide the high transparency of LiFePO4 thin films cathode materials and the good candidate as FTO current collector of the LiFePO4 thin film cathode of transparent thin film rechargeable batteries due to its high transparency and cyclic retention.

Measurements of higher order modes in a 30 cm long X-band structure

International Nuclear Information System (INIS)

Xiao, L.; Liang, Y.; Tong, D.; Zhang, H.

2001-01-01

The use of a cage of metallic wires as a bead is proposed to measure the higher order modes (HOMs) in an X-band accelerating structure. These long thin wires can isolate the longitudinal electric field component from other field components and produce sufficient frequency shift in bead-pull measurements. In the setup described in this paper, the bead is made by sputtering silver film onto a thin nylon line through a specially designed fixture. The cage has a size of approximately 0.5 mm in diameter, 2 mm in length and more than six metallic wires of less than 0.1 mm in width. The fabrication and calibration of the cage are described. The longitudinal electric fields of the lowest passband dipole mode TM 110 in a 30 cm long X-band structure are measured by bead-pull measurements. Results are compared with the calculated ones obtained from URMELT-code

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

Transparent megahertz circuits from solution-processed composite thin films.

Science.gov (United States)

Liu, Xingqiang; Wan, Da; Wu, Yun; Xiao, Xiangheng; Guo, Shishang; Jiang, Changzhong; Li, Jinchai; Chen, Tangsheng; Duan, Xiangfeng; Fan, Zhiyong; Liao, Lei

2016-04-21

Solution-processed amorphous oxide semiconductors have attracted considerable interest in large-area transparent electronics. However, due to its relative low carrier mobility (∼10 cm(2) V(-1) s(-1)), the demonstrated circuit performance has been limited to 800 kHz or less. Herein, we report solution-processed high-speed thin-film transistors (TFTs) and integrated circuits with an operation frequency beyond the megahertz region on 4 inch glass. The TFTs can be fabricated from an amorphous indium gallium zinc oxide/single-walled carbon nanotube (a-IGZO/SWNT) composite thin film with high yield and high carrier mobility of >70 cm(2) V(-1) s(-1). On-chip microwave measurements demonstrate that these TFTs can deliver an unprecedented operation frequency in solution-processed semiconductors, including an extrinsic cut-off frequency (f(T) = 102 MHz) and a maximum oscillation frequency (f(max) = 122 MHz). Ring oscillators further demonstrated an oscillation frequency of 4.13 MHz, for the first time, realizing megahertz circuit operation from solution-processed semiconductors. Our studies represent an important step toward high-speed solution-processed thin film electronics.

Crystallinity and electrical properties of neodymium-substituted bismuth titanate thin films

International Nuclear Information System (INIS)

Chen, Y.-C.; Hsiung, C.-P.; Chen, C.-Y.; Gan, J.-Y.; Sun, Y.-M.; Lin, C.-P.

2006-01-01

We report on the properties of Nd-substituted bismuth titanate Bi 4-x Nd x Ti 3 O 12 (BNdT) thin films for ferroelectric non-volatile memory applications. The Nd-substituted bismuth titanate thin films fabricated by modified chemical solution deposition technique showed much improved properties compared to pure bismuth titanate. A pyrochlore free crystalline phase was obtained at a low annealing temperature of 640 deg. C and grain size was found to be considerably increased as the annealing temperature increased. The film properties were found to be strongly dependent on the Nd content and annealing temperatures. The measured dielectric constant of BNdT thin films was in the range 172-130 for Bi 4-x Nd x Ti 3 O 12 with x 0.0-0.75. Ferroelectric properties of Nd-substituted bismuth titanate thin films were significantly improved compared to pure bismuth titanate. For example, the observed 2P r and E c for Bi 3.25 Nd 0.75 Ti 3 O 12 , annealed at 680 deg. C, were 38 μC/cm 2 and 98 kV/cm, respectively. The improved microstructural and ferroelectric properties of BNdT thin films suggest their suitability for high density ferroelectric random access memory applications

P-type thin films transistors with solution-deposited lead sulfide films as semiconductor

Energy Technology Data Exchange (ETDEWEB)

Carrillo-Castillo, A.; Salas-Villasenor, A.; Mejia, I. [Department of Materials Science and Engineering, The University of Texas at Dallas. 800 West Campbell Rd, Richardson, TX 75083 (United States); Aguirre-Tostado, S. [Centro de Investigacion en Materiales Avanzados, S. C. Alianza Norte 202, Parque de Investigacion e Innovacion Tecnologica, Apodaca, Nuevo Leon, C.P. 666000 (Mexico); Gnade, B.E. [Department of Materials Science and Engineering, University of Texas at Dallas. 800 West Campbell Rd, Richardson, TX 75083 (United States); Quevedo-Lopez, M.A., E-mail: mxq071000@utdallas.edu [Department of Materials Science and Engineering, University of Texas at Dallas. 800 West Campbell Rd, Richardson, TX 75083 (United States)

2012-01-31

In this paper we demonstrate p-type thin film transistors fabricated with lead sulfide (PbS) as semiconductor deposited by chemical bath deposition methods. Crystallinity and morphology of the resulting PbS films were characterized using X-ray diffraction, atomic force microscopy and scanning electron microscopy. Devices were fabricated using photolithographic processes in a bottom gate configuration with Au as source and drain top contacts. Field effect mobility for as-fabricated devices was {approx} 0.09 cm{sup 2} V{sup -1} s{sup -1} whereas the mobility for devices annealed at 150 Degree-Sign C/h in forming gas increased up to {approx} 0.14 cm{sup 2} V{sup -1} s{sup -1}. Besides the thermal annealing, the entire fabrications process was maintained below 100 Degree-Sign C. The electrical performance of the PbS-thin film transistors was studied before and after the 150 Degree-Sign C anneal as well as a function of the PbS active layer thicknesses. - Highlights: Black-Right-Pointing-Pointer Thin film transistors with PbS as semiconductor deposited by chemical bath deposition. Black-Right-Pointing-Pointer Photolithography-based thin film transistors with PbS films at low temperatures. Black-Right-Pointing-Pointer Electron mobility for anneal-PbS devices of {approx} 0.14 cm{sup 2} V{sup -1} s{sup -1}. Black-Right-Pointing-Pointer Highest mobility reported in thin film transistors with PbS as the semiconductor.

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.

Thermoelectric prospects of chemically deposited PbSe and SnSe thin films

Science.gov (United States)

Nair, P. K.; Martínez, Ana Karen; Rosa García Angelmo, Ana; Barrios Salgado, Enue; Nair, M. T. S.

2018-03-01

Thin films of PbSe of 400-600 nm in thickness, were obtained via chemical deposition from a solution containing lead nitrate, thiourea and selenosufate. SnSe thin films of 90-180 nm in thickness, were also obtained by chemical deposition from a solution containing selenosulfate. Optical and electrical properties of these thin films were significantly altered by heating them in selenium vapor at 300 °C. Thin film PbSe has a bandgap (Eg) of 1.17 eV (direct gap, forbidden transitions), which decreases to 0.77 eV when it has been heated. Its electrical conductivity (σ) is p-type: 0.18 Ω-1 cm-1 (as-prepared), and 6.4 Ω-1 cm-1 when heated. Thin film SnSe is of orthorhombic crystalline structure which remains stable when heated at 300 °C, but its Eg increases from 1.12 eV (indirect) in as-prepared film to 1.5 eV (direct, forbidden transitions) upon heating. Its electrical conductivity is p-type, which increases from 0.3 Ω-1 cm-1 (as-prepared) to 1 Ω-1 cm-1 when heated (without Se-vapor). When SnSe film is heated at 300 °C in the presence of Se-vapor, they transform to SnSe2, with Eg of 1.5 eV (direct, forbidden) with n-type electrical conductivity, 11 Ω-1 cm-1. The Seebeck coefficient for the PbSe films is: +0.55 mV K-1 (as prepared) and +0.275 mV K-1 (heated); for SnSe films it is: +0.3 mV K-1 (as prepared) and +0.20 mV K-1 (heated); and for SnSe2 film, - 0.35 mV K-1. A five-element PbSe-SnSe2-PbSe-SnSe2-PbSe thermoelectric device demonstrated 50 mV for a temperature difference ΔT = 20 °C (2.5 mV K-1). For SnSe-SnSe2-SnSe-SnSe2-SnSe device, the value is 15 mV for ΔT = 20 °C (0.75 mV K-1). Prospect of these thin films in thermoelectric devices of hybrid materials, in which the coatings may be applied on distinct substrate and geometries is attractive.

Critical role of alkyl chain branching of organic semiconductors in enabling solution-processed N-channel organic thin-film transistors with mobility of up to 3.50 cm² V(-1) s(-1).

Science.gov (United States)

Zhang, Fengjiao; Hu, Yunbin; Schuettfort, Torben; Di, Chong-an; Gao, Xike; McNeill, Christopher R; Thomsen, Lars; Mannsfeld, Stefan C B; Yuan, Wei; Sirringhaus, Henning; Zhu, Daoben

2013-02-13

Substituted side chains are fundamental units in solution processable organic semiconductors in order to achieve a balance of close intermolecular stacking, high crystallinity, and good compatibility with different wet techniques. Based on four air-stable solution-processed naphthalene diimides fused with 2-(1,3-dithiol-2-ylidene)malononitrile groups (NDI-DTYM2) that bear branched alkyl chains with varied side-chain length and different branching position, we have carried out systematic studies on the relationship between film microstructure and charge transport in their organic thin-film transistors (OTFTs). In particular synchrotron measurements (grazing incidence X-ray diffraction and near-edge X-ray absorption fine structure) are combined with device optimization studies to probe the interplay between molecular structure, molecular packing, and OTFT mobility. It is found that the side-chain length has a moderate influence on thin-film microstructure but leads to only limited changes in OTFT performance. In contrast, the position of branching point results in subtle, yet critical changes in molecular packing and leads to dramatic differences in electron mobility ranging from ~0.001 to >3.0 cm(2) V(-1) s(-1). Incorporating a NDI-DTYM2 core with three-branched N-alkyl substituents of C(11,6) results in a dense in-plane molecular packing with an unit cell area of 127 Å(2), larger domain sizes of up to 1000 × 3000 nm(2), and an electron mobility of up to 3.50 cm(2) V(-1) s(-1), which is an unprecedented value for ambient stable n-channel solution-processed OTFTs reported to date. These results demonstrate that variation of the alkyl chain branching point is a powerful strategy for tuning of molecular packing to enable high charge transport mobilities.

Evaluation of neutron cross sections for 244Cm, 246Cm, and 248Cm

International Nuclear Information System (INIS)

Benjamin, R.W.; McCrosson, F.J.; Gettys, W.E.

1977-01-01

An evaluation of neutron cross sections for 244 246 248 Cm using the ENDF/B format is presented. Primary data input included differential measurements, integral measurements, nuclear model calculations, and reactor production experience

243Cm half-life determinaton

International Nuclear Information System (INIS)

Timofeev, G.A.; Kalygin, V.V.; Privalova, P.A.

1986-01-01

By molar ratios of 243 Cm mixture with 244 Cm and Pu nuclides formed as a result of Cm nuclides α-decay the 243 Cm half-life T α243 is determined. The 244 Cm half-life is measured earlier with high accuracy. The 243 Cm/ 244 Cm ratio measured by means of a mass spectrometer equals 0.989+-0.004. The obtained value T α243 =29.20+-0.14 years

Tuning Bandgap of p-Type Cu2Zn(Sn, Ge)(S, Se)4 Semiconductor Thin Films via Aqueous Polymer-Assisted Deposition.

Science.gov (United States)

Yi, Qinghua; Wu, Jiang; Zhao, Jie; Wang, Hao; Hu, Jiapeng; Dai, Xiao; Zou, Guifu

2017-01-18

Bandgap engineering of kesterite Cu 2 Zn(Sn, Ge)(S, Se) 4 with well-controlled stoichiometric composition plays a critical role in sustainable inorganic photovoltaics. Herein, a cost-effective and reproducible aqueous solution-based polymer-assisted deposition approach is developed to grow p-type Cu 2 Zn(Sn, Ge)(S, Se) 4 thin films with tunable bandgap. The bandgap of Cu 2 Zn(Sn, Ge)(S, Se) 4 thin films can be tuned within the range 1.05-1.95 eV using the aqueous polymer-assisted deposition by accurately controlling the elemental compositions. One of the as-grown Cu 2 Zn(Sn, Ge)(S, Se) 4 thin films exhibits a hall coefficient of +137 cm 3 /C. The resistivity, concentration and carrier mobility of the Cu 2 ZnSn(S, Se) 4 thin film are 3.17 ohm·cm, 4.5 × 10 16 cm -3 , and 43 cm 2 /(V·S) at room temperature, respectively. Moreover, the Cu 2 ZnSn(S, Se) 4 thin film when used as an active layer in a solar cell leads to a power conversion efficiency of 3.55%. The facile growth of Cu 2 Zn(Sn, Ge)(S, Se) 4 thin films in an aqueous system, instead of organic solvents, provides great promise as an environmental-friendly platform to fabricate a variety of single/multi metal chalcogenides for the thin film industry and solution-processed photovoltaic devices.

Study of post annealing influence on structural, chemical and electrical properties of ZTO thin films

International Nuclear Information System (INIS)

Jain, Vipin Kumar; Kumar, Praveen; Kumar, Mahesh; Jain, Praveen; Bhandari, Deepika; Vijay, Y.K.

2011-01-01

Research highlights: → Structural, chemical and electrical properties of cost effective ZTO thin films with varying concentrations. → Effect of annealing of ZTO films. - Abstract: Zinc-Tin-Oxide (ZTO) thin films were deposited on glass substrate with varying concentrations (ZnO:SnO 2 ; 100:0, 90:10, 70:30 and 50:50 wt.%) at room temperature by flash evaporation technique. These deposited ZTO films were annealed at 450 deg. C in vacuum. These films were characterized to study the effect of annealing and addition of SnO 2 concentration on the structural, chemical and electrical properties. The XRD analysis indicates that crystallization of the ZTO films strongly depends on the concentration of SnO 2 and post annealing where annealed films showed polycrystalline nature. Atomic force microscopy (AFM) images manifest the surface morphology of these ZTO thin films. The XPS core level spectra of Zn(2p), O(1s) and Sn(3d) have been deconvoluted into their Gaussian component to evaluate the chemical changes, while valence band spectra reveal the electronic structures of these films. A small shift in Zn(2p) and Sn(3d) core level towards higher binding energy and O(1s) core level towards lower binding energy have been observed. The minimum electrical resistivity (ρ ∼ 3.69 x 10 -2 Ω-cm), maximum carrier concentration (n ∼ 3.26 x 10 19 cm -3 ) and Hall mobility (μ ∼ 5.2 cm 2 v -1 s -1 ) were obtained for as-prepared ZTO (50:50) film thereafter move towards lowest resistivity (ρ ∼ 1.12 x 10 -3 Ω-cm), highest carrier concentration (n ∼ 2.96 x 10 20 cm -3 ) and mobility (μ ∼ 18.8 cm 2 v -1 s -1 ) for annealed ZTO (50:50) thin film.

Preparation of air-settled, roll-thinned phosphorus targets

CERN Document Server

Lozowski, W R

1999-01-01

Red sup 3 sup 1 P targets of 2.6 and 2.9 mg/cm sup 2+-0.1 mg/cm sup 2 with 1-cmx2-cm side dimensions were prepared for a nuclear mass measurement which required good thickness uniformity. The thinner target, with 50 mu g/cm sup 2 of gold flashed on both surfaces, withstood a 173-MeV alpha beam of 175 nA for 18 h. Adaptations will be described for an Indiana University Cyclotron Facility air-settling method used to distribute phosphorus powder, as well as the methods developed for subsequent pressing, roll thinning, and dry release to obtain self-supporting targets. An envelope of gold foil, in contact with the phosphorus during each step, was instrumental in the process.

Preparation of Cu{sub 2}ZnSnS{sub 4} thin films by sulfurizing stacked precursor thin films via successive ionic layer adsorption and reaction method

Energy Technology Data Exchange (ETDEWEB)

Su Zhenghua; Yan Chang; Sun Kaiwen; Han Zili [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Liu Fangyang, E-mail: liufangyang@csu.edu.cn [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Liu Jin [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Lai Yanqing, E-mail: laiyanqingcsu@163.com [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Li Jie; Liu Yexiang [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China)

2012-07-15

Earth-abundant Cu{sub 2}ZnSnS{sub 4} is a promising alternative photovoltaic material which has been examined as absorber layer of thin film solar cells. In this study, Cu{sub 2}ZnSnS{sub 4} (CZTS) thin films have been successfully fabricated by sulfurizing stacked precursor thin films via successive ionic layer adsorption and reaction (SILAR) method. The prepared CZTS thin films have been characterized by X-ray diffraction, energy dispersive spectrometer, Raman spectroscopy, UV-vis spectroscopy, Hall effect measurements and photoelectrochemical tests. Results reveal that the thin films have kesterite structured Cu{sub 2}ZnSnS{sub 4} and the p-type conductivity with a carrier concentration in the order of 10{sup 18} cm{sup -3} and an optical band gap of 1.5 eV, which are suitable for applications in thin film solar cells.

Thin metal electrodes for semitransparent organic photovoltaics

KAUST Repository

Lee, Kyusung

2013-08-01

We demonstrate semitransparent organic photovoltaics (OPVs) based on thin metal electrodes and polymer photoactive layers consisting of poly(3-hexylthiophene) and [6,6]-phenyl C61 butyric acid methyl ester. The power conversion efficiency of a semitransparent OPV device comprising a 15-nm silver (Ag) rear electrode is 1.98% under AM 1.5-G illumination through the indium-tin-oxide side of the front anode at 100 mW/cm2 with 15.6% average transmittance of the entire cell in the visible wavelength range. As its thickness increases, a thin Ag electrode mainly influences the enhancement of the short circuit current density and fill factor. Its relatively low absorption intensity makes a Ag thin film a viable option for semitransparent electrodes compatible with organic layers. © 2013 ETRI.

Backdating of events in electronic primary health care data: should one censor at the date of last data collection.

Science.gov (United States)

Sammon, Cormac J; Petersen, Irene

2016-04-01

Studies using primary care databases often censor follow-up at the date data are last collected from clinical computer systems (last collection date (LCD)). We explored whether this results in the selective exclusion of events entered in the electronic health records after their date of occurrence, that is, backdated events. We used data from The Health Improvement Network (THIN). Using two versions of the database, we identified events that were entered into a later (THIN14) but not an earlier version of the database (THIN13) and investigated how the number of entries changed as a function of time since LCD. Times between events and the dates they were recorded were plotted as a function of time since the LCD in an effort to determine appropriate points at which to censor follow-up. There were 356 million eligible events in THIN14 and 355 million eligible events in THIN13. When comparing the two data sets, the proportion of missing events in THIN13 was highest in the month prior to the LCD (9.6%), decreasing to 5.2% at 6 months and 3.4% at 12 months. The proportion of missing events was largest for events typically diagnosed in secondary care such as neoplasms (28% in the month prior to LCD) and negligible for events typically diagnosed in primary care such as respiratory events (2% in the month prior to LCD). Studies using primary care databases, particularly those investigating events typically diagnosed outside primary care, should censor follow-up prior to the LCD to avoid underestimation of event rates. Copyright © 2016 John Wiley & Sons, Ltd.

Thin, Conductive, Pyrrolyc film production for radioactive sources backings

International Nuclear Information System (INIS)

Rodriguez, L.; Arcos, J.M. los

1993-01-01

A procedure for electro polymerization of pyrrole has been set up in order to produce thin, (> 15 μg/cm2) homogeneous (thickness variation < 2%) films, with no need for additional metallization to be used as backings of radioactive sources, having 10-0,4 Kfl/sample, for 35-70 μg/cm . The experimental equipment, reagent and procedure utilized is described as well as the characterization of Pyrrolyc films produced. (Author) 28 refs

Magnetoelectric coupling effect in transition metal modified polycrystalline BiFeO3 thin films

International Nuclear Information System (INIS)

Sreenivas Puli, Venkata; Kumar Pradhan, Dhiren; Gollapudi, Sreenivasulu; Coondoo, Indrani; Panwar, Neeraj; Adireddy, Shiva; Chrisey, Douglas B.; Katiyar, Ram S.

2014-01-01

Rare-earth (Sm) and transition metal (Co) modified polycrystalline BiFeO 3 (BFO) thin films have been deposited on Pt/TiO 2 /SiO 2 /Si substrate successfully through pulsed laser deposition (PLD) technique. Piezoelectric, leakage current and temperature dependent dielectric and magnetic behaviour were investigated for the films. Typical “butterfly-shaped” loop were observed in BSFCO films with an effective piezoelectric constant (d 33 ) ∼94 pm/V at 0.6 MV/cm. High dielectric constant ∼900 and low dielectric loss ∼0.25 were observed at room temperature. M–H loops have shown relatively high saturation magnetization ∼35 emu/cm 3 at a maximum field of H ∼20 kOe. Enhanced magnetoelectric coupling response is observed under applied magnetic field. The multiferroic, piezoelectric, leakage current behaviours were explored. Such studies should be helpful in designing multiferroic materials based on BSFCO films. - Highlights: • Transition metal modified polycrystalline BiFeO 3 thin films prepared using PLD. • High ME-coupling response was observed in co-substituted BiFeO 3 thin films. • High magnetization ∼35 emu/cm 3 at a maximum field of H ∼20 kOe. • Low leakage current might be due to co-substitution in BiFeO 3 thin films. • A notable piezoelectric constant d 33 ∼94 pm/V was found in BiFeO 3 thin films

Deposition of thin films and surface modification by pulsed high energy density plasma

International Nuclear Information System (INIS)

Yan Pengxun; Yang Size

2002-01-01

The use of pulsed high energy density plasma is a new low temperature plasma technology for material surface treatment and thin film deposition. The authors present detailed theoretical and experimental studies of the production mechanism and physical properties of the pulsed plasma. The basic physics of the pulsed plasma-material interaction has been investigated. Diagnostic measurements show that the pulsed plasma has a high electron temperature of 10-100 eV, density of 10 14 -10 16 cm -3 , translation velocity of ∼10 -7 cm/s and power density of ∼10 4 W/cm 2 . Its use in material surface treatment combines the effects of laser surface treatment, electron beam treatment, shock wave bombardment, ion implantation, sputtering deposition and chemical vapor deposition. The metastable phase and other kinds of compounds can be produced on low temperature substrates. For thin film deposition, a high deposition ratio and strong film to substrate adhesion can be achieved. The thin film deposition and material surface modification by the pulsed plasma and related physical mechanism have been investigated. Thin film c-BN, Ti(CN), TiN, DLC and AlN materials have been produced successfully on various substrates at room temperature. A wide interface layer exists between film and substrate, resulting in strong adhesion. Metal surface properties can be improved greatly by using this kind of treatment

Probability Estimates of Solar Particle Event Doses During a Period of Low Sunspot Number for Thinly-Shielded Spacecraft and Short Duration Missions

Science.gov (United States)

Atwell, William; Tylka, Allan J.; Dietrich, William; Rojdev, Kristina; Matzkind, Courtney

2016-01-01

In an earlier paper (Atwell, et al., 2015), we investigated solar particle event (SPE) radiation exposures (absorbed dose) to small, thinly-shielded spacecraft during a period when the sunspot number (SSN) was less than 30. These SPEs contain Ground Level Events (GLE), sub-GLEs, and sub-sub-GLEs (Tylka and Dietrich, 2009, Tylka and Dietrich, 2008, and Atwell, et al., 2008). GLEs are extremely energetic solar particle events having proton energies extending into the several GeV range and producing secondary particles in the atmosphere, mostly neutrons, observed with ground station neutron monitors. Sub-GLE events are less energetic, extending into the several hundred MeV range, but do not produce secondary atmospheric particles. Sub-sub GLEs are even less energetic with an observable increase in protons at energies greater than 30 MeV, but no observable proton flux above 300 MeV. In this paper, we consider those SPEs that occurred during 1973-2010 when the SSN was greater than 30 but less than 50. In addition, we provide probability estimates of absorbed dose based on mission duration with a 95% confidence level (CL). We also discuss the implications of these data and provide some recommendations that may be useful to spacecraft designers of these smaller spacecraft.

Oxygen barrier of multilayer thin films comprised of polysaccharides and clay.

Science.gov (United States)

Laufer, Galina; Kirkland, Christopher; Cain, Amanda A; Grunlan, Jaime C

2013-06-05

Multilayered thin films of chitosan (CH), carrageenan (CR) and montmorillonite (MMT) clay, deposited using the layer-by-layer technique, were studied in an effort to produce fully renewable polysaccharide-based thin films with low oxygen permeability. Ten 'trilayers' of CH/MMT/CR (film reduced its oxygen permeability (1.76×10(-15) cm(3) cm/cm(2) s Pa) by an order of magnitude under dry conditions. By adding an additional layer of CH to the trilayer sequence, a 'quadlayer' film of CH/CR/CH/MMT (barrier is believed to be due to the unique nanostructure of these films, often referred to as a "nanobrick wall" structure, as well as a strong association amongst the oppositely charged polysaccharides. Combining fully renewable and food contact approved ingredients with high gas barrier and optical transparency makes this technology promising as a foil replacement for food packaging. Copyright © 2013 Elsevier Ltd. All rights reserved.

Elaboration of strontium ruthenium oxide thin films on metal substrates by chemical solution deposition

International Nuclear Information System (INIS)

Seveno, R.; Braud, A.; Gundel, H.W.

2005-01-01

In order to improve the structural interface between a metal substrate and a lead zirconate titanate (Pb(ZrTi)O 3 , PZT) ferroelectric thin film, the elaboration of strontium ruthenium oxide (SrRuO 3 ) by chemical solution deposition is studied. The SrRuO 3 thin films were realized by multiple spin-coating technique and the temperature of the rapid thermal annealing process was optimized. The crystallization behavior was examined by X-ray diffraction; surface analyses using scanning electron microscope and atomic force microscope techniques showed the influence of the SrRuO 3 layer at the interface PZT/metal on the morphology of the ferroelectric thin film. From the electrical measurements, a coercive electric field around 25 kV/cm and a remanent polarization of approximately 30 μC/cm were found

YCo5±x thin films with perpendicular anisotropy grown by molecular beam epitaxy

Science.gov (United States)

Sharma, S.; Hildebrandt, E.; Sharath, S. U.; Radulov, I.; Alff, L.

2017-06-01

The synthesis conditions of buffer-free (00l) oriented YCo5 and Y2Co17 thin films onto Al2O3 (0001) substrates have been explored by molecular beam epitaxy (MBE). The manipulation of the ratio of individual atomic beams of Yttrium, Y and Cobalt, Co, as well as growth rate variations allows establishing a thin film phase diagram. Highly textured YCo5±x thin films were stabilized with saturation magnetization of 517 emu/cm3 (0.517 MA/m), coercivity of 4 kOe (0.4 T), and anisotropy constant, K1, equal to 5.34 ×106 erg/cm3 (0.53 MJ/m3). These magnetic parameters and the perpendicular anisotropy obtained without additional underlayers make the material system interesting for application in magnetic recording devices.

Preparation of PZT thin films on YBCO electrodes by KrF excimer laser ablation technique

International Nuclear Information System (INIS)

Kurogi, H.; Yamagata, Y.; Ebihara, K.

1998-01-01

Pb(Zr X Ti 1-X )O 3 (PZT) films have excellent ferroelectric, optical, piezoelectric, and pyroelectric properties. We prepared PZT thin films by the excimer laser ablation technique. A pulsed KrF excimer laser (Lambda Physik LPX305icc, pulse duration of 25 ns, λ=248 nm, 850 mJ Max.) was used to ablate the bulk targets. We investigated the influence of bottom electrode materials on the characteristics of the PZT thin films prepared on Pt and YBCO underlayers. The X-ray diffraction (XRD) patterns showed that the PZT films prepared with a laser fluence of 2 Jcm -2 on YBCO/MgO(100) substrate at a wide temperature range of 550-680 C have a perovskite (001) structure. At the same laser fluence, the PZT films prepared on Pt/MgO(100) substrate have a perovskite (001) structure only at 650 C. The polarization-electric field (P-E) characteristics and fatigue properties of PZT thin films were measured by the Sawyer-Tower circuit. The remnant polarization and coercive field have been found to be P r =15 μC cm -2 , 30 μC cm -2 and E c =200 kV cm -1 , 100 kV cm -1 for Au/PZT/Pt/MgO and Au/PZT/YBCO/MgO correspondingly. The remnant polarization of Au/PZT/YBCO/MgO thin film was reduced to one-half after about 10 8 cycles of switching. (orig.)

Chemical bath deposited and dip coating deposited CuS thin films - Structure, Raman spectroscopy and surface study

Science.gov (United States)

Tailor, Jiten P.; Khimani, Ankurkumar J.; Chaki, Sunil H.

2018-05-01

The crystal structure, Raman spectroscopy and surface microtopography study on as-deposited CuS thin films were carried out. Thin films deposited by two techniques of solution growth were studied. The thin films used in the present study were deposited by chemical bath deposition (CBD) and dip coating deposition techniques. The X-ray diffraction (XRD) analysis of both the as-deposited thin films showed that both the films possess covellite phase of CuS and hexagonal unit cell structure. The determined lattice parameters of both the films are in agreement with the standard JCPDS as well as reported data. The crystallite size determined by Scherrer's equation and Hall-Williamsons relation using XRD data for both the as-deposited thin films showed that the respective values were in agreement with each other. The ambient Raman spectroscopy of both the as-deposited thin films showed major emission peaks at 474 cm-1 and a minor emmision peaks at 265 cm-1. The observed Raman peaks matched with the covellite phase of CuS. The atomic force microscopy of both the as-deposited thin films surfaces showed dip coating thin film to be less rough compared to CBD deposited thin film. All the obtained results are presented and deliberated in details.

Polycystalline silicon thin films for electronic applications

Energy Technology Data Exchange (ETDEWEB)

Jaeger, Christian Claus

2012-01-15

For the thin polycrystalline Si films fabricated with the aluminium-induced-layer-exchange (ALILE) process a good structural quality up to a layer-thickness value of 10 nm was determined. For 5 nm thick layers however after the layer exchange no closes poly-silicon film was present. In this case the substrate was covered with spherically arranged semiconductor material. Furthermore amorphous contributions in the layer could be determined. The electrical characterization of the samples at room temperature proved a high hole concentration in the range 10{sup 18} cm{sup -3} up to 9.10{sup 19} cm{sup -3}, which is influenced by the process temperature and the layer thickness. Hereby higher hole concentrations at higher process temperatures and thinner films were observed. Furthermore above 150-200 K a thermically activated behaviour of the electrical conductivity was observed. At lower temperatures a deviation of the measured characteristic from the exponential Arrhenius behaviour was determined. For low temperatures (below 20 K) the conductivity follows the behaviour {sigma}{proportional_to}[-(T{sub 0}/T){sup 1/4}]. The hole mobility in the layers was lowered by a passivation step, which can be explained by defect states at the grain boundaries. The for these very thin layers present situation was simulated in the framework of the model of Seto, whereby both the defect states at the grain boundaries (with an area density Q{sub t}) and the defect states at the interfaces (with an area density Q{sub it}) were regarded. By this the values Q{sub t}{approx}(3-4).10{sup 12} cm{sup -2} and Q{sub it}{approx}(2-5).10{sup 12} cm{sup -2} could be determined for these thin ALILE layers on quartz substrates. Additionally th R-ALILE process was studied, which uses the reverse precursor-layer sequence substrate/amorphous silicon/oxide/aluminium. Hereby two steps in the crystallization process of the R-ALILE process were found. First a substrate/Al-Si mixture/poly-Si layer structure

Neutron spectra of /sup 242/Cm-Be and /sup 244/Cm-Be neutron sources

Energy Technology Data Exchange (ETDEWEB)

Kumar, A; Nagarajan, P S [Bhabha Atomic Research Centre, Bombay (India). Div. of Radiation Protection

1977-02-15

Neutron spectra of /sup 242/Cm-Be(..cap alpha..,n) and /sup 244/Cm-Be(..cap alpha..,n) sources have been calculated including the spontaneous fission contribution which is negligible for /sup 242/Cm and amounts to about 4% for /sup 244/Cm. The agreement of the present work with experimental results is poor.

Optical and infrared spectroscopic studies of chemical sensing by copper phthalocyanine thin films

International Nuclear Information System (INIS)

Singh, Sukhwinder; Tripathi, S.K.; Saini, G.S.S.

2008-01-01

Thin films of copper phthalocyanine have been deposited on KBr and glass substrates by thermal evaporation method and characterized by the X-ray diffraction and optical absorption techniques. The observed X-ray pattern suggests the presence of α crystalline phase of copper phthalocyanine in the as-deposited thin films. Infrared spectra of thin films on the KBr pallet before and after exposure to the vapours of ammonia and methanol have been recorded in the wavenumber region of 400-1650 cm -1 . The observed infrared bands also confirm the α crystalline phase. On exposure, change in the intensity of some bands is observed. A new band at 1385 cm -1 , forbidden under ideal D 4h point group symmetry, is also observed in the spectra of exposed thin films. These changes in the spectra are interpreted in terms of the lowering of molecular symmetry from D 4h to C 4v . Axial ligation of the vapour molecules on fifth coordination site of the metal ion is responsible for lowering of the molecular symmetry

Performance of a polymer electrolyte membrane fuel cell with thin film catalyst electrodes

Energy Technology Data Exchange (ETDEWEB)

Chun, Young Gab; Kim, Chang Soo; Peck, Dong Hyun; Shin, Dong Ryul [Korea Institute of Energy Research, Taejon (Korea, Republic of)

1998-03-15

In order to develop a kW-class polymer electrolyte membrane fuel cell (PEMFC), several electrodes have been fabricated by different catalyst layer preparation procedures and evaluated based on the cell performance. Conventional carbon paper and carbon cloth electrodes were fabricated using a ptfe-bonded Pt/C electrol catalyst by coating and rolling methods. Thin-film catalyst/ionomer composite layers were also formed on the membrane by direct coating and transfer printing techniques. The performance evaluation with catalyst layer preparation methods was carried out using a large or small electrode single cell. Conventional and thin film membrane and electrode assemblies (MEAs) with small electrode area showed a performance of 350 and 650 mA/cm{sup 2} at 0.6 V, respectively. The performance of direct coated thin film catalyst layer with 300 cm{sup 2} MEAs was higher than those of the conventional and transfer printing technique MEAs. The influence of some characteristic parameters of the thin film electrode on electrochemical performance was examined. Various other aspects of overall operation of PEMFC stacks were also discussed. (orig.)

Preparation and properties of the (Sr,BaNb2O6 thin films by using the sputtering method

Directory of Open Access Journals (Sweden)

Diao Chien-Chen

2017-01-01

Full Text Available Strontium barium niobate (Sr0.3Ba0.7Nb2O6, SBN thin films were deposited on silicon substrate by using the radio frequency magnetron sputtering and under different deposition power and time at room temperature. Surface morphology and thicknesses of the SBN thin films were characterized by field emission scanning electron microscopy. The crystallization films at different deposition power and time were analyzed by X-ray diffraction (XRD using CuKα radiation from a Rigaku rotating anode with an incident angle of 2°. The remnant polarization (Pr, saturation polarization (Ps, and minimum coercive field (Ec properties of the metal-ferroelectric-metal (MFM structure were measured using ferroelectric material test instrument. The SBN thin films deposited at 90 min and 125 W had the maximum Pr, Ps, and minimum Ec of 1.26 μC/cm2, 2.41 μC/cm2, and 201.6 kV/cm, respectively. From above results, it knows that the SBN thin films suit for application on ferroelectric random access memory (FeRAM.

Effect of doping concentration on the conductivity and optical properties of p-type ZnO thin films

Energy Technology Data Exchange (ETDEWEB)

Pathak, Trilok Kumar [Semiconductor Research Lab, Department of Physics, Gurukula Kangri University, Haridwar (India); Kumar, Vinod, E-mail: vinod.phy@gmail.com [Department of Physics, University of the Free State, Bloemfontein (South Africa); Swart, H.C., E-mail: swarthc@ufs.ac.za [Department of Physics, University of the Free State, Bloemfontein (South Africa); Purohit, L.P., E-mail: proflppurohitphys@gmail.com [Semiconductor Research Lab, Department of Physics, Gurukula Kangri University, Haridwar (India)

2016-01-01

Nitrogen doped ZnO (NZO) thin films were synthesized on glass substrates by the sol–gel and spin coating method. Zinc acetate dihydrates and ammonium acetate were used as precursors for zinc and nitrogen, respectively. X-ray diffraction study showed that the thin films have a hexagonal wurtzite structure corresponding (002) peak for undoped and doped ZnO thin films. The transmittance of the films was above 80% and the band gap of the film varies from 3.21±0.03 eV for undoped and doped ZnO. The minimum resistivity of NZO thin films was obtained as 0.473 Ω cm for the 4 at% of nitrogen (N) doping with a mobility of 1.995 cm{sup 2}/V s. The NZO thin films showed p-type conductivity at 2 and 3 at% of N doping. The AC conductivity measurements that were carried out in the frequency range 10 kHz to 0.1 MHz showed localized conduction in the NZO thin films. These highly transparent ZnO films can be used as a possible window layer in solar cells.

Transparent, high mobility InGaZnO thin films deposited by PLD

International Nuclear Information System (INIS)

Suresh, Arun; Gollakota, Praveen; Wellenius, Patrick; Dhawan, Anuj; Muth, John F.

2008-01-01

Transparent oxide semiconductor, InGaZnO, thin films were prepared by pulsed laser deposition at room temperature. The carrier concentration was found to vary by several orders of magnitude from insulating to 10 19 carriers/cm 3 depending on the oxygen partial pressure during deposition. Hall mobilities as high as 16 cm 2 /V s were observed. This is approximately an order of magnitude higher than the mobility of amorphous silicon and indicates that InGaO 3 (ZnO) x with x ≤ 5 may be suitable for transparent, thin film transistor applications. Post-deposition annealing was found to strongly influence the carrier concentration while annealing effects on the electron mobility was less influential

Inconsistent Growth Response to Fertilization and Thinning of Lodgepole Pine in the Rocky Mountain Foothills Is Linked to Site Index

Directory of Open Access Journals (Sweden)

Bradley D. Pinno

2012-01-01

Full Text Available Fertilization of conifers often results in highly variable growth responses across sites which are difficult to predict. The goal of this study was to predict the growth response of lodgepole pine (Pinus contorta var. latifolia crop trees to thinning and fertilization using basic site and foliar characteristics. Fifteen harvest-origin stands along the foothills of the Rocky Mountains of Alberta were subjected to six treatments including two levels of thinning (thinning to 2500 stems per hectare and a control and three types of fertilization (nitrogen-only fertilization, complete fertilization including nitrogen with added P, K, S, Mg, and B, and no fertilization. After three growing seasons, the growth response and foliar status of the crop trees were examined and this response was related to site and foliar characteristics. There was a small and highly variable additive response to fertilization and thinning; diameter growth of crop trees increased relative to the controls an average of 0.3 cm with thinning, 0.3 cm with either N-only or complete fertilization and 0.6 cm when thinned and fertilized. The increase in diameter growth with thinning and nitrogen-only fertilization was positively related to site index but not to any other site factors or pretreatment foliar variables such as nutrient concentrations, ratios, or thresholds.

Magnetoelectric coupling effect in transition metal modified polycrystalline BiFeO{sub 3} thin films

Energy Technology Data Exchange (ETDEWEB)

Sreenivas Puli, Venkata, E-mail: pvsri123@gmail.com [Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118 (United States); Department of Physics and Institute of Functional Nanomaterials, University of Puerto Rico, San Juan, PR 00936 (United States); Kumar Pradhan, Dhiren [Department of Physics and Institute of Functional Nanomaterials, University of Puerto Rico, San Juan, PR 00936 (United States); Gollapudi, Sreenivasulu [Department of Physics, Oakland University, Rochester, MI 48309-4401 (United States); Coondoo, Indrani [Department of Materials and Ceramic and CICECO, University of Aveiro, 3810-193 Aveiro (Portugal); Panwar, Neeraj [Department of Physics, Central University of Rajasthan, Bandar Sindri, Kishangarh 305801, Rajasthan (India); Adireddy, Shiva; Chrisey, Douglas B. [Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118 (United States); Katiyar, Ram S. [Department of Physics and Institute of Functional Nanomaterials, University of Puerto Rico, San Juan, PR 00936 (United States)

2014-11-15

Rare-earth (Sm) and transition metal (Co) modified polycrystalline BiFeO{sub 3} (BFO) thin films have been deposited on Pt/TiO{sub 2}/SiO{sub 2}/Si substrate successfully through pulsed laser deposition (PLD) technique. Piezoelectric, leakage current and temperature dependent dielectric and magnetic behaviour were investigated for the films. Typical “butterfly-shaped” loop were observed in BSFCO films with an effective piezoelectric constant (d{sub 33}) ∼94 pm/V at 0.6 MV/cm. High dielectric constant ∼900 and low dielectric loss ∼0.25 were observed at room temperature. M–H loops have shown relatively high saturation magnetization ∼35 emu/cm{sup 3} at a maximum field of H ∼20 kOe. Enhanced magnetoelectric coupling response is observed under applied magnetic field. The multiferroic, piezoelectric, leakage current behaviours were explored. Such studies should be helpful in designing multiferroic materials based on BSFCO films. - Highlights: • Transition metal modified polycrystalline BiFeO{sub 3} thin films prepared using PLD. • High ME-coupling response was observed in co-substituted BiFeO{sub 3} thin films. • High magnetization ∼35 emu/cm{sup 3} at a maximum field of H ∼20 kOe. • Low leakage current might be due to co-substitution in BiFeO{sub 3} thin films. • A notable piezoelectric constant d{sub 33} ∼94 pm/V was found in BiFeO{sub 3} thin films.

Junctionless Thin-Film Transistors Gated by an H₃PO₄-Incorporated Chitosan Proton Conductor.

Science.gov (United States)

Liu, Huixuan; Xun, Damao

2018-04-01

We fabricated an H3PO4-incorporated chitosan proton conductor film that exhibited the electric double layer effect and showed a high specific capacitance of 4.42 μF/cm2. Transparent indium tin oxide thin-film transistors gated by H3PO4-incorporated chitosan films were fabricated by sputtering through a shadow mask. The operating voltage was as low as 1.2 V because of the high specific capacitance of the H3PO4-incorporated chitosan dielectrics. The junctionless transparent indium tin oxide thin film transistors exhibited good performance, including an estimated current on/off ratio and field-effect mobility of 1.2 × 106 and 6.63 cm2V-1s-1, respectively. These low-voltage thin-film electric-double-layer transistors gated by H3PO4-incorporated chitosan are promising for next generation battery-powered "see-through" portable sensors.

Phenomenological understanding of dewetting and embedding of noble metal nanoparticles in thin films induced by ion irradiation

Energy Technology Data Exchange (ETDEWEB)

Prakash, Jai, E-mail: jai.gupta1983@gmail.com [Department of Chemistry, MMH College (Ch. Charan Singh University Meerut), Ghaiziabad 201001 (India); Chemical Physics of Materials, Université Libre de Bruxelles, Campus de la Plaine, CP 243, B-1050 Bruxelles (Belgium); Tripathi, A. [Inter University Accelerator Centre, Aruna Asif Ali Marg, New Delhi 110067 (India); Gautam, Sanjeev; Chae, K.H.; Song, Jonghan [Advanced Analysis Center, Korea Institute of Science and Technology, Seoul 136–791 (Korea, Republic of); Rigato, V. [INFN Laboratori Nazionali di Legnaro, Via Romea. 4, 35020 Legnaro, Padova (Italy); Tripathi, Jalaj [Department of Chemistry, MMH College (Ch. Charan Singh University Meerut), Ghaiziabad 201001 (India); Asokan, K. [Inter University Accelerator Centre, Aruna Asif Ali Marg, New Delhi 110067 (India)

2014-10-15

The present experimental work provides the phenomenological approach to understand the dewetting in thin noble metal films with subsequent formation of nanoparticles (NPs) and embedding of NPs induced by ion irradiation. Au/polyethyleneterepthlate (PET) bilayers were irradiated with 150 keV Ar ions at varying fluences and were studied using scanning electron microscopy (SEM) and cross-sectional transmission electron microscopy (X-TEM). Thin Au film begins to dewet from the substrate after irradiation and subsequent irradiation results in spherical nanoparticles on the surface that at a fluence of 5 × 10{sup 16} ions/cm{sup 2} become embedded into the substrate. In addition to dewetting in thin films, synthesis and embedding of metal NPs by ion irradiation, the present article explores fundamental thermodynamic principles that govern these events systematically under the effect of irradiation. The results are explained on the basis of ion induced sputtering, thermal spike inducing local melting and of thermodynamic driving forces by minimization of the system free energy where contributions of surface and interfacial energies are considered with subsequent ion induced viscous flow in substrate. - Highlights: • Phenomenological interpretation of dewetting and embedding of metal NPs in thin film. • Exploring fundamental thermodynamic principles under influence of ion irradiation. • Ion induced surface/interface microstructural changes using SEM/X-TEM. • Ion induced sputtering, thermal spike induced local melting. • Thermodynamic driving forces relate to surface and interfacial energies.

Pentiptycene-based polyurethane with enhanced mechanical properties and CO2-plasticization resistance for thin film gas separation membranes.

Science.gov (United States)

Pournaghshband Isfahani, Ali; Sadeghi, Morteza; Wakimoto, Kazuki; Shrestha, Binod Babu; Bagheri, Rouhollah; Sivaniah, Easan; Ghalei, Behnam

2018-04-30

Development of thin film composite (TFC) membranes offers an opportunity to achieve the permeability/selectivity requirements for optimum CO2 separation performance. However, the durability and performance of thin film gas separation membranes are mostly challenged by weak mechanical properties and high CO2 plasticization. Here, we designed new polyurethane (PU) structures with bulky aromatic chain extenders that afford preferred mechanical properties for ultra-thin film formation. An improvement of about 1500% in Young's modulus and 600% in hardness was observed for pentiptycene-based PUs compared to typical PU membranes. Single (CO2, H2, CH4, and N2) and mixed (CO2/N2 and CO2/CH4) gas permeability tests were performed on the PU membranes. The resulting TFC membranes showed a high CO2 permeance up to 1400 GPU (10-6 cm3(STP) cm-2s-1 cmHg-1) and the CO2/N2 and CO2/H2 selectivities of about 22 and 2.1, respectively. The enhanced mechanical properties of pentiptycene-based PUs results in high performance thin membranes with the similar selectivity of the bulk polymer. The thin film membranes prepared from pentiptycene-based PUs also showed a two-fold enhanced plasticization resistance compared to non-pentiptycene containing PU membranes.

Electrochemical fabrication of nanoporous polypyrrole thin films

Energy Technology Data Exchange (ETDEWEB)

Li Mei [Key Laboratory of Organic Optoelectronics and Molecular Engineering (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084 (China); Yuan Jinying [Key Laboratory of Organic Optoelectronics and Molecular Engineering (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084 (China)], E-mail: yuanjy@mail.tsinghua.edu.cn; Shi Gaoquan [Key Laboratory of Organic Optoelectronics and Molecular Engineering (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084 (China)], E-mail: gshi@mail.tsinghua.edu.cn

2008-04-30

Polypyrrole thin films with pores in nanometer scale were synthesized by direct electrochemical oxidation of pyrrole in a mixed electrolyte of isopropyl alcohol, boron trifluoride diethyl etherate, sodium dodecylsulfonate and poly(ethylene glycol) using well-aligned ZnO nanowires arrays as templates. The thin films exhibit high conductivity of ca. {sigma}{sub rt} {approx} 20.5 s/cm and can be driven to bend during redox processes in 1.0 M lithium perchlorate aqueous solution. The movement rate of an actuator based on this nanoporous film was measured to be over 90{sup o}/s at a driving potential of 0.8 V (vs. Ag/AgCl)

Electrochemical fabrication of nanoporous polypyrrole thin films

International Nuclear Information System (INIS)

Li Mei; Yuan Jinying; Shi Gaoquan

2008-01-01

Polypyrrole thin films with pores in nanometer scale were synthesized by direct electrochemical oxidation of pyrrole in a mixed electrolyte of isopropyl alcohol, boron trifluoride diethyl etherate, sodium dodecylsulfonate and poly(ethylene glycol) using well-aligned ZnO nanowires arrays as templates. The thin films exhibit high conductivity of ca. σ rt ∼ 20.5 s/cm and can be driven to bend during redox processes in 1.0 M lithium perchlorate aqueous solution. The movement rate of an actuator based on this nanoporous film was measured to be over 90 o /s at a driving potential of 0.8 V (vs. Ag/AgCl)

Elaboration of strontium ruthenium oxide thin films on metal substrates by chemical solution deposition

Energy Technology Data Exchange (ETDEWEB)

Seveno, R. [Universite de Nantes, Institut de Recherche en Electrotechnique et Electronique de Nantes Atlantique (IREENA), 2, rue de la Houssiniere, BP 92208, 44322 Nantes Cedex 3 (France)]. E-mail: raynald.seveno@univ-nantes.fr; Braud, A. [Universite de Nantes, Institut de Recherche en Electrotechnique et Electronique de Nantes Atlantique (IREENA), 2, rue de la Houssiniere, BP 92208, 44322 Nantes Cedex 3 (France); Gundel, H.W. [Universite de Nantes, Institut de Recherche en Electrotechnique et Electronique de Nantes Atlantique (IREENA), 2, rue de la Houssiniere, BP 92208, 44322 Nantes Cedex 3 (France)

2005-12-22

In order to improve the structural interface between a metal substrate and a lead zirconate titanate (Pb(ZrTi)O{sub 3}, PZT) ferroelectric thin film, the elaboration of strontium ruthenium oxide (SrRuO{sub 3}) by chemical solution deposition is studied. The SrRuO{sub 3} thin films were realized by multiple spin-coating technique and the temperature of the rapid thermal annealing process was optimized. The crystallization behavior was examined by X-ray diffraction; surface analyses using scanning electron microscope and atomic force microscope techniques showed the influence of the SrRuO{sub 3} layer at the interface PZT/metal on the morphology of the ferroelectric thin film. From the electrical measurements, a coercive electric field around 25 kV/cm and a remanent polarization of approximately 30 {mu}C/cm were found.

Influence of precursor concentration on physical properties of CdO thin films prepared by spray pyrolysis technique using nebulizer

Energy Technology Data Exchange (ETDEWEB)

Anitha, M.; Amalraj, L.; Anitha, N. [Virudhunagar Hindu Nadar' s Senthikumara Nadar College (Autonomous), Department of Physics, Virudhunagar, Tamilnadu (India)

2017-12-15

Cadmium oxide (CdO) thin films were prepared with different concentrations of precursor solution (0.05, 0.1, 0.15, 0.2 and 0.25 M, respectively) at the optimized temperature (200 C) using the nebulized spray pyrolysis technique to obtain better crystallinity in polycrystalline thin films on amorphous glass substrates. The XRD characterization of those samples revealed a preferential orientation along the (111) plane having a cubic structure. The scanning electron microscopy (SEM) analysis displayed that all the as-deposited thin films have spherical shaped grains. The transmittance of the as-deposited CdO thin films had decreased from 88 to 71% for longer wavelength regions (600-900 nm) as the precursor concentration had increased and then increased for higher precursor concentration. The optical band gap was found to lie between 2.45 and 2.40 eV belonging to direct transition for those thin films. The presence of Cd-O bond (540 cm{sup -1}) was confirmed by FTIR spectrum. The emission properties of CdO thin films were studied by luminescence spectrum recorded at room temperature. A maximum carrier concentration and minimum resistivity values of 4.743 x 10{sup 19} cm{sup -3} and 1.06 x 10{sup -3} Ω-cm, respectively, were obtained for 0.2 M precursor concentration. These CdO thin films have high optical transmittance and high room temperature conductivity, which can be used as the TCO and Solar cell (window layer) material. (orig.)

Facile chemical synthesis of nanoporous layered δ-MnO{sub 2} thin film for high-performance flexible electrochemical capacitors

Energy Technology Data Exchange (ETDEWEB)

Hu, Yu; Wang, Jun; Jiang, Xionghua; Zheng, Yanfeng [The Key Laboratory of Low-Carbon Chemistry and Energy Conservation of Guangdong Province, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Chen, Zhenxing, E-mail: chenzx65@mail.sysu.edu.cn [The Key Laboratory of Low-Carbon Chemistry and Energy Conservation of Guangdong Province, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China)

2013-04-15

Layered δ-MnO{sub 2} thin films with a three-dimensional nanostructure are successfully fabricated on stainless steel foil substrates for flexible electrochemical capacitors by a facile and effective chemical bath deposition technology from ethanol and potassium permanganate solution at 15 °C. The as-prepared thin films display nanoporous morphology and a water contact angle of 20°. Energy-dispersive X-ray spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy analyses reveal that the thin films are composed of δ-MnO{sub 2}. Electrochemical data demonstrate that the δ-MnO{sub 2} thin film electrodes can deliver a high special capacitance of 447 F/g at 2 mV/s, and provide a good capacitance retention ratio of 87% after 1000 continuous cycles at 10 mV/s in 0.5 M Na{sub 2}SO{sub 4}. Compressive and tensile bending tests show that the as-prepared electrodes can steadily work over a wide range of applied curvatures between −2.5 cm{sup −1} (tension) and 2.5 cm{sup −1} (compression). Only a small decrease in special capacitance (0.9% at a curvature of 2.5 cm{sup −1} under compressive strain, or 1.2% at a curvature of −2.5 cm{sup −1} under tensile strain) is observed even after bending for 200 cycles, indicating the excellent mechanical flexibility and electrochemical stability of the δ-MnO{sub 2} thin film electrodes.

Thin, Flexible Secondary Li-Ion Paper Batteries

KAUST Repository

Hu, Liangbing

2010-10-26

There is a strong interest in thin, flexible energy storage devices to meet modern society needs for applications such as interactive packaging, radio frequency sensing, and consumer products. In this article, we report a new structure of thin, flexible Li-ion batteries using paper as separators and free-standing carbon nanotube thin films as both current collectors. The current collectors and Li-ion battery materials are integrated onto a single sheet of paper through a lamination process. The paper functions as both a mechanical substrate and separator membrane with lower impedance than commercial separators. The CNT film functions as a current collector for both the anode and the cathode with a low sheet resistance (∼5 Ohm/sq), lightweight (∼0.2 mg/cm2), and excellent flexibility. After packaging, the rechargeable Li-ion paper battery, despite being thin (∼300 μm), exhibits robust mechanical flexibility (capable of bending down to <6 mm) and a high energy density (108 mWh/g). © 2010 American Chemical Society.

Downscaling of South America present climate driven by 4-member HadCM3 runs

Energy Technology Data Exchange (ETDEWEB)

Chou, Sin Chan; Marengo, Jose A.; Lyra, Andre A.; Sueiro, Gustavo; Pesquero, Jose F.; Alves, Lincoln M.; Chagas, Diego J.; Gomes, Jorge L.; Bustamante, Josiane F.; Tavares, Priscila [National Institute for Space Research (INPE), Sao Paulo (Brazil); Kay, Gillian; Betts, Richard [UK Met Office Hadley Centre, Devon (United Kingdom)

2012-02-15

The objective of this work is to evaluate climate simulations over South America using the regional Eta Model driven by four members of an ensemble of the UK Met Office Hadley Centre HadCM3 global model. The Eta Model has been modified with the purpose of performing long-term decadal integrations and has shown to reproduce ''present climate'' - the period 1961-1990 - reasonably well when forced by HadCM3. The global model lateral conditions with a resolution of 2.5 latitude x 3.75 longitude were provided at a frequency of 6 h. Each member of the global model ensemble has a different climate sensitivity, and the four members were selected to span the range of uncertainty encompassed by the ensemble. The Eta Model nested in the HadCM3 global model was configured with 40-km horizontal resolution and 38 layers in the vertical. No large-scale internal nudging was applied. Results are shown for austral summer and winter at present climate defined as 1961-90. The upper and low-level circulation patterns produced by the Eta-CPTEC/HadCM3 experiment set-up show good agreement with reanalysis data and the mean precipitation and temperature with CRU observation data. The spread in the downscaled mean precipitation and temperature is small when compared against model errors. On the other hand, the benefits in using an ensemble is clear in the improved representation of the seasonal cycle by the ensemble mean over any one realization. El Nino and La Nina years were identified in the HadCM3 member runs based on the NOAA Climate Prediction Center criterion of sea surface temperature anomalies in the Nino 3.4 area. The frequency of the El Nino and La Nina events in the studied period is underestimated by HadCM3. The precipitation and temperature anomalies typical of these events are reproduced by most of the Eta-CPTEC/HadCM3 ensemble, although small displacements of the positions of the anomalies occur. This experiment configuration is the first step on the

Preparation of PZT thin films on YBCO electrodes by KrF excimer laser ablation technique

Energy Technology Data Exchange (ETDEWEB)

Kurogi, H; Yamagata, Y; Ebihara, K [Kumamoto Univ. (Japan). Dept. of Electr. Eng. and Comput. Sci.; Inoue, N [Kyushu Electric Power Co., Inc., Suizenji, 1-6-36, Kumamoto 862 (Japan)

1998-03-01

Pb(Zr{sub X}Ti{sub 1-X})O{sub 3} (PZT) films have excellent ferroelectric, optical, piezoelectric, and pyroelectric properties. We prepared PZT thin films by the excimer laser ablation technique. A pulsed KrF excimer laser (Lambda Physik LPX305icc, pulse duration of 25 ns, {lambda}=248 nm, 850 mJ Max.) was used to ablate the bulk targets. We investigated the influence of bottom electrode materials on the characteristics of the PZT thin films prepared on Pt and YBCO underlayers. The X-ray diffraction (XRD) patterns showed that the PZT films prepared with a laser fluence of 2 Jcm{sup -2} on YBCO/MgO(100) substrate at a wide temperature range of 550-680 C have a perovskite (001) structure. At the same laser fluence, the PZT films prepared on Pt/MgO(100) substrate have a perovskite (001) structure only at 650 C. The polarization-electric field (P-E) characteristics and fatigue properties of PZT thin films were measured by the Sawyer-Tower circuit. The remnant polarization and coercive field have been found to be P{sub r}=15 {mu}C cm{sup -2}, 30 {mu}C cm{sup -2} and E{sub c}=200 kV cm{sup -1}, 100 kV cm{sup -1} for Au/PZT/Pt/MgO and Au/PZT/YBCO/MgO correspondingly. The remnant polarization of Au/PZT/YBCO/MgO thin film was reduced to one-half after about 10{sup 8} cycles of switching. (orig.) 7 refs.

Multivariate analysis as a tool in the assesment of thinning of segae date palm cultivar (phoenix dactylifera L.)

International Nuclear Information System (INIS)

Al-Obeed, R. S.; Al-Saif, A. M.; Soliman, S. S.

2015-01-01

Different hand thinning treatments were conducted on Segae date palm cultivar to study their effect on bunch yield and fruit quality. Five thinning treatments; control (no thinning (A)), removing 10 cm of strands length per bunch (B), removing 20 cm of strands length per bunch (C), removing the middle of the bunch (D), removing the middle of the bunch and removing 10 cm of strands length per bunch (E) were investigated at Deirab, Riyadh, Saudi Arabia. Fruit thinning substantially decreased bunch yield and increased fruit weight, flesh weight, flesh weight, fruit size, fruit dimensions in both seasons as compared with the control (no thinning) treatment. Fruit thinning had significant effect on the fruit acidity, total soluble solids and total sugars in both seasons. Thinning treatments had no effect on seed weight, reducing sugars, non-reducing sugars and moisture content in two seasons. It could be recommended that removing the middle of the bunch and removing 10 cm of strands length per bunch (treatment E) is the most appropriate practice for thinning as it gave the highest bunch yield with best fruit quality as compared with other applied treatments. Principle component analysis determined into three components which explained 82.92 percentage and 82.11 percentage of the total variance in the first and second seasons, respectively. First component (50.98 percentage and 43.20 percentage) strongly influenced by fruit length, fruit diameter, fruit weight, fruit volume, seed weight and flesh weight at first and second seasons, respectively. second component (19.69 percentage and 24.95) was affected strongly by total sugars, non-reducing sugars and bunch weight and total sugars, non-reducing sugars at first and second seasons, respectively. Third component (12.24 percentage and 13.97) was affected strongly by total soluble solids and moisture content at first and second seasons, respectively. This information can be used for future studies and can be used in

Substrate decoration for improvement of current-carrying capabilities of YBa2Cu3Ox thin films

International Nuclear Information System (INIS)

Khoryushin, Alexey V.; Mozhaev, Peter B.; Mozhaeva, Julia E.; Bdikin, Igor K.; Zhao, Yue; Andersen, Niels H.; Jacobsen, Claus S.; Hansen, Jørn Bindslev

2013-01-01

Highlights: ► Effects of substrate decoration on properties of YBCO thin films were studied. ► Y 2 O 3 nanoparticles, ultra-thin Y 2 O 3 and Y:ZrO 2 layers were used as decoration layer. ► Decoration improves j C (5 T and 50 K) up to 0.97 MA/cm 2 vs. 0.76 MA/cm 2 for a reference film. ► Ultra-thin layer of yttria and yttria nanoparticles have a similar effect on YBCO. ► Y 2 O 3 decoration results in power law coefficient α = 0.3 vs. α = 0.4 for a reference film. -- Abstract: The effects of substrate decoration with yttria and Y:ZrO 2 on the structural and electrical properties of the YBa 2 Cu 3 O x (YBCO) thin films are studied. The films were deposited on (LaAlO 3 ) 3 –(Sr 2 AlTaO 8 ) 7 substrates by pulsed laser deposition. Two different structures of decoration layer were applied, a template layer of nanoparticles and an uniform ultra-thin layer. Significant improvement of current-carrying capabilities was observed, especially at high external magnetic fields. Structural studies of these films reveal the presence of extended linear defects in the YBCO matrix. The formation of these structures is attributed to seeding of randomly oriented YBCO grains due to suppression of epitaxy in the very beginning of the deposition. The films of both kinds of decoration layers show nearly the same improvement of j C over the reference film at 77 and 50 K: j C (5T and 50 K) reaches 0.92 and 0.97 MA/cm 2 for uniform and template decoration layers. At 5 and 20 K the effect of template decoration layers is more beneficial: j C (5T and 20 K) values are 3.5 and 4.1 MA/cm 2 , j C (5T and 5 K) values are 6.4 and 7.9 MA/cm 2 , for uniform and template decoration layers, respectively

Production of optically thin free-standing oil films from the edge of a rotating disc

International Nuclear Information System (INIS)

Cramer, J.G.; Burch, D.F.; Rodenberg, R.; Cramer, P.B.

1980-01-01

A method is described for forming thin free-standing oil films which are spun from the edge of a sharp-edged rotating disc. The films can be made thin enough to show strong optical interference colors when viewed in white light. The thinnest films have areal densities down to about 10 to 20 μgm/cm 2 . A stable roughly triangular film with an area of about 10 cm 2 and fairly uniform thickness can be readily produced. Much larger films having either greater thickness or less stability are also possible. Films have been produced both in air and in vacuum

Polycrystalline thin films of antimony selenide via chemical bath deposition and post deposition treatments

International Nuclear Information System (INIS)

Rodriguez-Lazcano, Y.; Pena, Yolanda; Nair, M.T.S.; Nair, P.K.

2005-01-01

We report a method for obtaining thin films of polycrystalline antimony selenide via chemical bath deposition followed by heating the thin films at 573 K in selenium vapor. The thin films deposited from chemical baths containing one or more soluble complexes of antimony, and selenosulfate initially did not show X-ray diffraction (XRD) patterns corresponding to crystalline antimony selenide. Composition of the films, studied by energy dispersive X-ray analyses indicated selenium deficiency. Heating these films in presence of selenium vapor at 573 K under nitrogen (2000 mTorr) resulted in an enrichment of Se in the films. XRD peaks of such films matched Sb 2 Se 3 . Evaluation of band gap from optical spectra of such films shows absorption due to indirect transition occurring in the range of 1-1.2 eV. The films are photosensitive, with dark conductivity of about 2 x 10 -8 (Ω cm) -1 and photoconductivity, about 10 -6 (Ω cm) -1 under tungsten halogen lamp illumination with intensity of 700 W m -2 . An estimate for the mobility life time product for the film is 4 x 10 -9 cm 2 V -1

Separation and recovery of Cm from Cm-Pu mixed oxide samples containing Am impurity

International Nuclear Information System (INIS)

Hirokazu Hayashi; Hiromichi Hagiya; Mitsuo Akabori; Yasuji Morita; Kazuo Minato

2013-01-01

Curium was separated and recovered as an oxalate from a Cm-Pu mixed oxide which had been a 244 Cm oxide sample prepared more than 40 years ago and the ratio of 244 Cm to 240 Pu was estimated to 0.2:0.8. Radiochemical analyses of the solution prepared by dissolving the Cm-Pu mixed oxide in nitric acid revealed that the oxide contained about 1 at% of 243 Am impurity. To obtain high purity curium solution, plutonium and americium were removed from the solution by an anion exchange method and by chromatographic separation using tertiary pyridine resin embedded in silica beads with nitric acid/methanol mixed solution, respectively. Curium oxalate, a precursor compound of curium oxide, was prepared from the purified curium solution. 11.9 mg of Cm oxalate having some amounts of impurities, which are 243 Am (5.4 at%) and 240 Pu (0.3 at%) was obtained without Am removal procedure. Meanwhile, 12.0 mg of Cm oxalate (99.8 at% over actinides) was obtained with the procedure including Am removals. Both of the obtained Cm oxalate sample were supplied for the syntheses and measurements of the thermochemical properties of curium compounds. (author)

Electrical and optical properties of spray - deposited CdSe thin films

International Nuclear Information System (INIS)

Bedir, M.; Oeztas, M.; Bakkaloglu, O. F.

2002-01-01

The CdSe thin films were developed by using spray-deposition technique at different substrate temperatures of 380C, 400C and, 420C on the glass substrate. All spraying processes involved CdCI 2 (0.05 moles/liter) and SeO 2 (0.05 moles/liter ) and were carried out in atmospheric condition. The CdSe thin film samples were characterized using x-ray diffractometer and optical absorption measurements. The electrical properties of the thin film samples were investigated via Wander Pauw method. XRD patterns indicated that the CdSe thin film samples have a hexagonal structure. The direct band gap of the CdSe thin film samples were determined from optical absorption and spectral response measurements of 1.76 eV. The resistivity of the CdSe thin film samples were found to vary in the range from 5.8x10''5 to 7.32x10''5 Ωcm depending to the substrate temperature

Processing of C60 thin films by Matrix-Assisted Pulsed Laser Evaporation (MAPLE)

DEFF Research Database (Denmark)

Canulescu, Stela; Schou, Jørgen; Fæster, Søren

2011-01-01

Thin films of fullerenes (C60) were deposited onto silicon using matrix-assisted pulsed laser evaporation (MAPLE). The deposition was carried out from a frozen homogeneous dilute solution of C60 in anisole (0.67 wt%), and over a broad range of laser fluences, from 0.15 J/cm2 up to 3.9 J/cm2. MAPLE...

Synthesis of Cu2O from CuO thin films: Optical and electrical properties

Directory of Open Access Journals (Sweden)

Dhanya S. Murali

2015-04-01

Full Text Available Hole conducting, optically transparent Cu2O thin films on glass substrates have been synthesized by vacuum annealing (5×10−6 mbar at 700 K for 1 hour of magnetron sputtered (at 300 K CuO thin films. The Cu2O thin films are p-type and show enhanced properties: grain size (54.7 nm, optical transmission 72% (at 600 nm and Hall mobility 51 cm2/Vs. The bulk and surface Valence band spectra of Cu2O and CuO thin films are studied by temperature dependent Hall effect and Ultra violet photo electron Spectroscopy (UPS. CuO thin films show a significant band bending downwards (due to higher hole concentration than Cu2O thin films.

Optoelectronic properties of cadmium sulfide thin films deposited by thermal evaporation technique

International Nuclear Information System (INIS)

Ali, N.; Iqbal, M.A.; Hussain, S.T.; Waris, M.; Munair, S.A.

2011-01-01

The substrate temperature in depositions of thin films plays a vital role in the characteristics of deposited films. We studied few characteristics of cadmium sulphide thin film deposited at different temperature (150 deg. C- 300 deg. C) on corning 7059 glass substrate. We measured transmittance, absorbance, band gap and reflectance via UV spectroscopy. It was found that the transmittance for 300 nm to 1100 nm was greater than 80%. The resistivity and mobility was calculated by Vander Pauw method which were 10-80 cm and 2-60 cm/sup 2/V/sup -1/S/sup -1/ respectively. The thermoelectric properties of the film were measured by hot and cold probe method which shows the N-type nature of the film. (author)

Indium Sulfide and Indium Oxide Thin Films Spin-Coated from Triethylammonium Indium Thioacetate Precursor for n-Channel Thin Film Transistor

Energy Technology Data Exchange (ETDEWEB)

Tung, Duy Dao; Jeong, Hyun Dam [Chonnam Natioal University, Gwangju (Korea, Republic of)

2014-09-15

The In{sub 2}S{sub 3} thin films of tetragonal structure and In{sub 2}O{sub 3} films of cubic structure were synthesized by a spin coating method from the organometallic compound precursor triethylammonium indium thioacetate ([(Et){sub 3}NH]+ [In(SCOCH{sub 3}){sub 4}]''-; TEA-InTAA). In order to determine the electron mobility of the spin-coated TEA-InTAA films, thin film transistors (TFTs) with an inverted structure using a gate dielectric of thermal oxide (SiO{sub 2}) was fabricated. These devices exhibited n-channel TFT characteristics with a field-effect electron mobility of 10.1 cm''2 V''-1s''-1 at a curing temperature of 500 o C, indicating that the semiconducting thin film material is applicable for use in low-cost, solution-processed printable electronics.

Pulsed laser deposition of transparent conductive oxide thin films on flexible substrates

International Nuclear Information System (INIS)

Socol, G.; Socol, M.; Stefan, N.; Axente, E.; Popescu-Pelin, G.; Craciun, D.; Duta, L.; Mihailescu, C.N.; Mihailescu, I.N.; Stanculescu, A.; Visan, D.; Sava, V.; Galca, A.C.; Luculescu, C.R.; Craciun, V.

2012-01-01

Highlights: ► TCO thin films were grown by PLD on PET substrate at low temperature. ► We found that the quality of TCO on PET substrate depends on the target–substrate distance. ► TCO with high transparency (>95%) and reduced electrical resistivity (∼5 × 10 −4 Ω cm) were obtained. ► Optimized TCO films deposited on PET were free of any cracks. - Abstract: The influence of target–substrate distance during pulsed laser deposition of indium zinc oxide (IZO), indium tin oxide (ITO) and aluminium-doped zinc oxide (AZO) thin films grown on polyethylene terephthalate (PET) substrates was investigated. It was found that the properties of such flexible transparent conductive oxide (TCO)/PET electrodes critically depend on this parameter. The TCO films that were deposited at distances of 6 and 8 cm exhibited an optical transmittance higher than 90% in the visible range and electrical resistivities around 5 × 10 −4 Ω cm. In addition to these excellent electrical and optical characteristics the films grown at 8 cm distance were homogenous, smooth, adherent, and without cracks or any other extended defects, being suitable for opto-electronic device applications.

Heavy and frequent thinning promotes drought adaptation in Pinus sylvestris forests.

Science.gov (United States)

Sohn, Julia A; Hartig, Florian; Kohler, Martin; Huss, Jürgen; Bauhus, Jürgen

2016-10-01

Droughts and their negative effects on forest ecosystems are projected to increase under climate change for many regions. It has been suggested that intensive thinning could reduce drought impacts on established forests in the short-term. Most previous studies on the effect of thinning on drought impacts, however, have been confined to single forest sites. It is therefore still unclear how general and persisting the benefits of thinning are. This study assesses the potential of thinning to increase drought tolerance of the wide spread Scots pine (Pinus sylvestris) in Central Europe. We hypothesized (1) that increasing thinning intensity benefits the maintenance of radial growth of crop trees during drought (resistance) and its recovery following drought, (2) that those benefits to growth decrease with time elapsed since the last thinning and with stand age, and (3) that they may depend on drought severity as well as water limitations in pre- and post-drought periods. To test these hypotheses, we assessed the effects of thinning regime, stand age, and drought severity on radial growth of 129 Scots pine trees during and after drought events in four long-term thinning experiments in Germany. We found that thinning improved the recovery of radial growth following drought and to a lesser extent the growth resistance during a drought event. Growth recovery following drought was highest after the first thinning intervention and in recently and heavily thinned stands. With time since the last thinning, however, this effect decreased and could even become negative when compared to unthinned stands. Further, thinning helped to avoid an age-related decline in growth resistance (and recovery) following drought. The recovery following drought, but not the resistance during drought, was related to water limitations in the drought period. This is the first study that analyzed drought-related radial growth in trees of one species across several stands of different age. The

Ablative acceleration of thin foil targets by intense proton beams

International Nuclear Information System (INIS)

Miyamoto, S.; Ozaki, T.; Imasaki, K.; Higaki, S.; Nakai, S.

1981-01-01

A focused proton beam of up to 2 x 10 10 w/cm 2 was obtained using pinch-reflex ion diode connected to Reiden IV generator. Experiments of beam target interaction have been done using thin foil targets. In this power range the interaction was explained classically. The experimental dependence of ablation pressure on proton beam intensity was obtained as P sub(a) = 3 x 10 -3 I sup(0.7) bar (I in w/cm 2 ). (author)

Characterization of sputter deposited thin film scandate cathodes for miniaturized thermionic converter applications

Science.gov (United States)

Zavadil, Kevin R.; Ruffner, Judith H.; King, Donald B.

1999-01-01

We have successfully developed a method for fabricating scandate-based thermionic emitters in thin film form. The primary goal of our effort is to develop thin film emitters that exhibit low work function, high intrinsic electron emissivity, minimum thermal activation properties and that can be readily incorporated into a microgap converter. Our approach has been to incorporate BaSrO into a Sc2O3 matrix using rf sputtering to produce thin films. Diode testing has shown the resulting films to be electron emissive at temperatures as low as 900 K with current densities of 0.1 mA.cm-2 at 1100 K and saturation voltages. We calculate an approximate maximum work function of 1.8 eV and an apparent emission constant (Richardson's constant, A*) of 36 mA.cm-2.K-2. Film compositional and structural analysis shows that a significant surface and subsurface alkaline earth hydroxide phase can form and probably explains the limited utilization and stability of Ba and its surface complexes. The flexibility inherent in sputter deposition suggests alternate strategies for eliminating undesirable phases and optimizing thin film emitter properties.

Lanthanide-Assisted Deposition of Strongly Electro-optic PZT Thin Films on Silicon: Toward Integrated Active Nanophotonic Devices.

Science.gov (United States)

George, J P; Smet, P F; Botterman, J; Bliznuk, V; Woestenborghs, W; Van Thourhout, D; Neyts, K; Beeckman, J

2015-06-24

The electro-optical properties of lead zirconate titanate (PZT) thin films depend strongly on the quality and crystallographic orientation of the thin films. We demonstrate a novel method to grow highly textured PZT thin films on silicon using the chemical solution deposition (CSD) process. We report the use of ultrathin (5-15 nm) lanthanide (La, Pr, Nd, Sm) based intermediate layers for obtaining preferentially (100) oriented PZT thin films. X-ray diffraction measurements indicate preferentially oriented intermediate Ln2O2CO3 layers providing an excellent lattice match with the PZT thin films grown on top. The XRD and scanning electron microscopy measurements reveal that the annealed layers are dense, uniform, crack-free and highly oriented (>99.8%) without apparent defects or secondary phases. The EDX and HRTEM characterization confirm that the template layers act as an efficient diffusion barrier and form a sharp interface between the substrate and the PZT. The electrical measurements indicate a dielectric constant of ∼650, low dielectric loss of ∼0.02, coercive field of 70 kV/cm, remnant polarization of 25 μC/cm(2), and large breakdown electric field of 1000 kV/cm. Finally, the effective electro-optic coefficients of the films are estimated with a spectroscopic ellipsometer measurement, considering the electric field induced variations in the phase reflectance ratio. The electro-optic measurements reveal excellent linear effective pockels coefficients of 110 to 240 pm/V, which makes the CSD deposited PZT thin film an ideal candidate for Si-based active integrated nanophotonic devices.

Indium sulfide thin films as window layer in chemically deposited solar cells

Energy Technology Data Exchange (ETDEWEB)

Lugo-Loredo, S. [Universidad Autónoma de Nuevo León, UANL, Fac. de Ciencias Químicas, Av. Universidad S/N Ciudad Universitaria San Nicolás de Los Garza Nuevo León, C.P. 66451 (Mexico); Peña-Méndez, Y., E-mail: yolapm@gmail.com [Universidad Autónoma de Nuevo León, UANL, Fac. de Ciencias Químicas, Av. Universidad S/N Ciudad Universitaria San Nicolás de Los Garza Nuevo León, C.P. 66451 (Mexico); Calixto-Rodriguez, M. [Universidad Tecnológica Emiliano Zapata del Estado de Morelos, Av. Universidad Tecnológica No. 1, C.P. 62760 Emiliano Zapata, Morelos (Mexico); Messina-Fernández, S. [Universidad Autónoma de Nayarit, Ciudad de la Cultura “Amado Nervo” S/N, C.P. 63190 Tepic, Nayarit (Mexico); Alvarez-Gallegos, A. [Universidad Autónoma del Estado de Morelos, Centro de Investigación en Ingeniería y Ciencias Aplicadas, Av. Universidad 1001, C.P. 62209, Cuernavaca Morelos (Mexico); Vázquez-Dimas, A.; Hernández-García, T. [Universidad Autónoma de Nuevo León, UANL, Fac. de Ciencias Químicas, Av. Universidad S/N Ciudad Universitaria San Nicolás de Los Garza Nuevo León, C.P. 66451 (Mexico)

2014-01-01

Indium sulfide (In{sub 2}S{sub 3}) thin films have been synthesized by chemical bath deposition technique onto glass substrates using In(NO{sub 3}){sub 3} as indium precursor and thioacetamide as sulfur source. X-ray diffraction studies have shown that the crystalline state of the as-prepared and the annealed films is β-In{sub 2}S{sub 3}. Optical band gap values between 2.27 and 2.41 eV were obtained for these films. The In{sub 2}S{sub 3} thin films are photosensitive with an electrical conductivity value in the range of 10{sup −3}–10{sup −7} (Ω cm){sup −1}, depending on the film preparation conditions. We have demonstrated that the In{sub 2}S{sub 3} thin films obtained in this work are suitable candidates to be used as window layer in thin film solar cells. These films were integrated in SnO{sub 2}:F/In{sub 2}S{sub 3}/Sb{sub 2}S{sub 3}/PbS/C–Ag solar cell structures, which showed an open circuit voltage of 630 mV and a short circuit current density of 0.6 mA/cm{sup 2}. - Highlights: • In{sub 2}S{sub 3} thin films were deposited using the Chemical Bath Deposition technique. • A direct energy band gap between 2.41 to 2.27 eV was evaluated for the In{sub 2}S{sub 3} films. • We made chemically deposited solar cells using the In{sub 2}S{sub 3} thin films.

A Novel Slicing Method for Thin Supercapacitors.

Science.gov (United States)

Sun, Hao; Fu, Xuemei; Xie, Songlin; Jiang, Yishu; Guan, Guozhen; Wang, Bingjie; Li, Houpu; Peng, Huisheng

2016-08-01

Thin and flexible supercapacitors with low cost and individual variation are fabricated by a new and efficient slicing method. Tunable output voltage and energy can be realized with a high specific capacitance of 248.8 F g(-1) or 150.8 F cm(-3) , which is well maintained before and after bending. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Clinical Features of Ground Glass Opacity-Dominant Lung Cancer Exceeding 3.0 cm in the Whole Tumor Size.

Science.gov (United States)

Suzuki, Shigeki; Sakurai, Hiroyuki; Yotsukura, Masaya; Masai, Kyohei; Asakura, Keisuke; Nakagawa, Kazuo; Motoi, Noriko; Watanabe, Shun-Ichi

2018-05-01

Ground glass opacity (GGO)-dominant lung adenocarcinoma sized 3.0 cm or less in the whole tumor size is widely known to have an excellent prognosis and is regarded as early lung cancer. However, the characteristics and prognosis of lung cancer showing GGO exceeding 3.0 cm remains unclear. From 2002 through 2012, we reviewed 3,735 lung cancers that underwent complete resection at our institution. We identified 160 lung cancers (4.3%) showing GGO exceeding 3.0 cm on thin-section computed tomography and divided them into three types by the consolidation/tumor ratio (CTR) using cutoff values of 0.25 and 0.5. We compared the characteristics and prognosis among these types. Type A (CTR, 0 to ≤0.25), type B (CTR, >0.25 to ≤0.5), and type C (CTR, >0.5 to 3.0 cm can be considered to be in a group of patients with nodal-negative disease and an excellent prognosis. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Thinness at birth in a northern industrial town.

Science.gov (United States)

Law, C M; Barker, D J; Richardson, W W; Shiell, A W; Grime, L P; Armand-Smith, N G; Cruddas, A M

1993-08-01

To determine whether babies in an area of Britain with unusually high perinatal mortality have different patterns of fetal growth to those born elsewhere in the country. Measurement of body size in newborn babies. Burnley (perinatal mortality in 1988 15.9/1000 total births) and Salisbury (perinatal mortality 10.8/1000 total births), England. Subjects comprised 1544 babies born in Burnley, Pendle, and Rossendale Health District, and 1025 babies born in Salisbury Health District. Birthweight, length, head, arm and abdominal circumferences, and placental weight were determined. Compared with babies born in Salisbury, Burnley babies had lower mean birthweight (difference 116 g, 95% confidence interval (CI) 77,154), smaller head circumferences (difference 0.3 cm, 95% CI 0.2, 0.4), and were thinner as measured by arm circumference (difference 0.3 cm, 95% CI 0.3, 0.4), abdominal circumference (difference 0.5 cm, 95% CI 0.4, 0.6) and ponderal index (difference 0.8 kg/m3, 95% CI 0.6, 1.0). The ratio of placental weight to birthweight was higher in Burnley (difference 0.6%, 95% CI 0.4, 0.9). These differences were found in boys and girls and did not depend on differences in duration of gestation or on the different ethnic mix of the two districts. Mothers in Burnley were younger, shorter in stature, had had more children, were of lower social class, and more of them smoked during pregnancy than mothers in Salisbury. These differences did not explain the greater thinness of their babies. Babies born in Burnley, an area with high perinatal mortality, are thin. The reason is unknown. Poor maternal nutrition is suspected because Burnley babies have a higher ratio of placental weight to birthweight. The greater thinness at birth of Burnley babies could have long term consequences, including higher rates of cardiovascular disease.

Comparison of nonflare solar soft x ray flux with 10.7-cm radio flux

International Nuclear Information System (INIS)

Donnelly, R.F.

1982-01-01

The similarities and differences of the nonflare solar 1- to 8-A X ray flux and the daily 10.7-cm Ottawa solar radio flux are examined. The radio flux is shown to be much less sensitive than the soft X ray flux on the average to the coronal emission of active regions located near or beyond the solar chromospheric limb relative to regions near the center of the solar disk. This is caused by the solar soft X ray emission's being optically thin while much of the 10.7-cm active region emission is from optical depths of tauapprox.1. The radio flux includes a large quiet sun flux which is emitted mostly from the tenuous chromosphere-corona transition region (Tapprox.10 4 --10 6 0 K) and partly from the cooler portions of the quiet corona Tapprox.1.5 x 10 6 0 K. Conversely, the solar soft X ray flux has a very small quiet sun component

Three-dimensional thin film for lithium-ion batteries and supercapacitors.

Science.gov (United States)

Yang, Yang; Peng, Zhiwei; Wang, Gunuk; Ruan, Gedeng; Fan, Xiujun; Li, Lei; Fei, Huilong; Hauge, Robert H; Tour, James M

2014-07-22

Three-dimensional heterogeneously nanostructured thin-film electrodes were fabricated by using Ta2O5 nanotubes as a framework to support carbon-onion-coated Fe2O3 nanoparticles along the surface of the nanotubes. Carbon onion layers function as microelectrodes to separate the two different metal oxides and form a nanoscale 3-D sandwich structure. In this way, space-charge layers were formed at the phase boundaries, and it provides additional energy storage by charge separation. These 3-D nanostructured thin films deliver both excellent Li-ion battery properties (stabilized at 800 mAh cm(–3)) and supercapacitor (up to 18.2 mF cm(–2)) performance owing to the synergistic effects of the heterogeneous structure. Thus, Li-ion batteries and supercapacitors are successfully assembled into the same electrode, which is promising for next generation hybrid energy storage and delivery devices.

Low-temperature growth and electronic structures of ambipolar Yb-doped zinc tin oxide transparent thin films

Science.gov (United States)

Oh, Seol Hee; Ferblantier, Gerald; Park, Young Sang; Schmerber, Guy; Dinia, Aziz; Slaoui, Abdelilah; Jo, William

2018-05-01

The compositional dependence of the crystal structure, optical transmittance, and surface electric properties of the zinc tin oxide (Zn-Sn-O, shortened ZTO) thin films were investigated. ZTO thin films with different compositional ratios were fabricated on glass and p-silicon wafers using radio frequency magnetron sputtering. The binding energy of amorphous ZTO thin films was examined by a X-ray photoelectron spectroscopy. The optical transmittance over 70% in the visible region for all the ZTO films was observed. The optical band gap of the ZTO films was changed as a result of the competition between the Burstein-Moss effect and renormalization. An electron concentration in the films and surface work function distribution were measured by a Hall measurement and Kelvin probe force microscopy, respectively. The mobility of the n- and p-type ZTO thin films have more than 130 cm2/V s and 15 cm2/V s, respectively. We finally constructed the band structure which contains band gap, work function, and band edges such as valence band maximum and conduction band minimum of ZTO thin films. The present study results suggest that the ZTO thin film is competitive compared with the indium tin oxide, which is a representative material of the transparent conducting oxides, regarding optoelectronic devices applications.

Characteristics of thin-film transistors based on silicon nitride passivation by excimer laser direct patterning

International Nuclear Information System (INIS)

Chen, Chao-Nan; Huang, Jung-Jie

2013-01-01

This study explored the removal of silicon nitride using KrF laser ablation technology with a high threshold fluence of 990 mJ/cm 2 . This technology was used for contact hole patterning to fabricate SiN x -passivation-based amorphous-silicon thin films in a transistor device. Compared to the photolithography process, laser direct patterning using KrF laser ablation technology can reduce the number of process steps by at least three. Experimental results showed that the mobility and threshold voltages of thin film transistors patterned using the laser process were 0.16 cm 2 /V-sec and 0.2 V, respectively. The device performance and the test results of gate voltage stress reliability demonstrated that laser direct patterning is a promising alternative to photolithography in the panel manufacturing of thin-film transistors for liquid crystal displays. - Highlights: ► KrF laser ablation technology is used to remove silicon nitride. ► A simple method for direct patterning contact-hole in thin-film-transistor device. ► Laser technology reduced processing by at least three steps

Influence of high energy ion irradiation on fullerene derivative (PCBM) thin films

Energy Technology Data Exchange (ETDEWEB)

Sharma, Trupti, E-mail: tsphy91@gmail.com [Department of Physics, Malaviya National Institute of Technology, Jaipur 302017 (India); Singhal, Rahul; Vishnoi, Ritu [Department of Physics, Malaviya National Institute of Technology, Jaipur 302017 (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)

2017-04-01

Highlights: • Spin casted PCBM thin films (∼100 nm) are irradiated with 55 MeV Si{sup 4+} ion beam. • The decrease in band gap is observed after irradiation. • The surface properties is also dependent on incident ion fluences. • Polymerization reactions induced by energetic ions leads to modifications. - Abstract: The modifications produced by 55 MeV Si{sup 4+} swift heavy ion irradiation on the phenyl C{sub 61} butyric acid methyl ester (PCBM) thin films (thickness ∼ 100 nm) has been enlightened. The PCBM thin films were irradiated at 1 × 10{sup 10}, 1 × 10{sup 11} and 1 × 10{sup 12} ions/cm{sup 2} fluences. After ion irradiation, the decreased optical band gap and FTIR band intensities were observed. The Raman spectroscopy reveals the damage produced by energetic ions. The morphological variation were investigated by atomic force microscopy and contact angle measurements and observed to be influenced by incident ion fluences. After 10{sup 11} ions/cm{sup 2} fluence, the overlapping of ion tracks starts and produced overlapping effects.

Effects of Naphthalene Acetic Acid and Carbaryl on Fruit Thinning in ‘Kinnow’ Mandarin Trees

Directory of Open Access Journals (Sweden)

Golnar Safaei-Nejad

2015-04-01

Full Text Available Several fruit trees including some cultivars of citrus tend to develop irregular bearing. Fruit thinning has been used for hundreds of years to manipulate blooming and crop load to improve the alternate bearing process. Frequently, combination sprays of two or more chemical thinners are used in various fruit trees and the thinning responses were additive and more effective than individual compounds. In this study, we investigated the effects of Naphthalene acetic acid and carbaryl alone and in combination in thinning of ‘Kinnow’ mandarin (Citrus reticulata Blanco trees. Some characteristics such as fruit weight, diameter and volume, total soluble solid (TSS, titrable acidity (TA, TSS/TA, vitamin C and peel thickness were measured prior to harvest for 2010 and 2011 as a complete randomized block design with 13 treatments and four replications. Results showed that the application of NAA and carbaryl alone in June drop stage of fruit growth increased fruit thinning percentage, TSS of fruit juice, fruit weight, volume, diameter and length. These chemical thinners improved fruit size significantly by increasing the leaf/fruit ratio. Combination sprays could not effectively thin fruits than individual chemicals and thus had no effect on fruit size. Fruit characteristics such as TA, ascorbic acid, TSS/TA ratio and peel thickness were not affected by our treatments.  Normal 0 false false false EN-US X-NONE AR-SA /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso

Thinning regimes and initial spacing for Eucalyptus plantations in Brazil.

Science.gov (United States)

Ferraz Filho, Antonio C; Mola-Yudego, Blas; González-Olabarria, José R; Scolforo, José Roberto S

2018-01-01

This study focuses on the effects of different thinning regimes on clonal Eucalyptus plantations growth. Four different trials, planted in 1999 and located in Bahia and Espírito Santo States, were used. Aside from thinning, initial planting density, and post thinning fertilization application were also evaluated. Before canopy closure, and therefore before excessive competition between trees took place, it was found that stands planted under low densities (667 trees per hectare) presented a lower mortality proportion when compared to stand planted under higher densities (1111 trees per hectare). However, diameter growth prior to thinning operations was not statistically different between these two densities, presenting an overall mean of 4.9 cm/year. After canopy closure and the application of the thinning treatments, it was found that thinning regimes beginning early in the life of the stand and leaving a low number of residual trees presented the highest diameter and height growth. Unthinned treatments and thinning regimes late in the life of the stand (after 5.5 years), leaving a large number of residual trees presented the highest values of basal area production. The choice of the best thinning regime for Eucalyptus clonal material will vary according to the plantation objective.

Linear luminescence for thin plastic scintillator under intense soft X-ray irradiation

International Nuclear Information System (INIS)

Ning Jiamin; Jiang Shilun; Xu Rongkun; Guo Cun

2006-01-01

The basic principle of soft X-ray power meter is introduced in the paper and the experimental process and the result of thin plastic scintillator linear luminescence under intense soft X-ray irradiation are described. A range of flux density of energy for thin plastic scintillator linear luminescence under intense soft X-ray irradiation is included. The upper limit of the flux density is 1.47 x 10 5 W/cm 2 . (authors)

Electrodeposition of CdTe thin film from acetate-based ionic liquid bath

Science.gov (United States)

Waldiya, Manmohansingh; Bhagat, Dharini; Mukhopadhyay, Indrajit

2018-05-01

CdTe being a direct band gap semiconductor, is mostly used in photovoltaics. Here we present, the synthesis of CdTe thin film on fluorine doped tin oxide (FTO) substrate potentiostatically using 1-butyl-3-methylimidazolium acetate ([Bmim][Ac]) ionic liquid (IL) bath at 90 °C. Major advantages of using electrodeposition involves process simplicity, large scalability & economic viability. Some of the benefits offered by IL electrolytic bath are low vapour pressure, wide electrochemical window, and good ionic mobility. Cd(CH3COO)2 (anhydrous) and TeO2 were used as the source precursors. The IL electrolytic bath temperature was kept at 90 °C for deposition, owing to the limited solubility of TeO2 in [Bmim][Ac] IL at room temperature. Cathodic electrodeposition was carried out using a three electrode cell setup at a constant potential of -1.20 V vs. platinum (Pt) wire. The CdTe/FTO thin film were annealed in argon (Ar) atmosphere. Optical study of nanostructured CdTe film were done using UV-Vis-IR and Raman spectroscopy. Raman analysis confirms the formation of CdTe having surface optics (SO) mode at 160.6 cm-1 and transverse optics (TO) mode at 140.5 cm-1. Elemental Te peaks at 123, 140.5 and 268 cm-1 were also observed. The optical band gap of Ar annealed CdTe thin film were found to be 1.47 eV (absorbance band edge ˜ 846 nm). The optimization of deposition parameters using acetate-based IL electrolytic bath to get nearly stoichiometric CdTe thin film is currently being explored.

Azaisoindigo conjugated polymers for high performance n-type and ambipolar thin film transistor applications

KAUST Repository

Yue, Wan

2016-09-28

Two new alternating copolymers, PAIIDBT and PAIIDSe have been prepared by incorporating a highly electron deficient azaisoindigo core. The molecular structure and packing of the monomer is determined from the single crystal X-ray diffraction. Both polymers exhibit high EAs and highly planar polymer backbones. When polymers are used as the semiconducting channel for solution-processed thin film transistor application, good properties are observed. A–A type PAIIDBT exhibits unipolar electron mobility as high as 1.0 cm2 V−1 s−1, D–A type PAIIDSe exhibits ambipolar charge transport behavior with predominately electron mobility up to 0.5 cm2 V−1 s−1 and hole mobility to 0.2 cm2 V−1 s−1. The robustness of the extracted mobility values are also commented on in detail. Molecular orientation, thin film morphology and energetic disorder of both polymers are systematically investigated.

Paper-based transparent flexible thin film supercapacitors

Science.gov (United States)

Gao, Kezheng; Shao, Ziqiang; Wu, Xue; Wang, Xi; Zhang, Yunhua; Wang, Wenjun; Wang, Feijun

2013-05-01

Paper-based transparent flexible thin film supercapacitors were fabricated using CNF-[RGO]n hybrid paper as an electrode material and charge collector. Owing to the self-anti-stacking of distorted RGO nanosheets and internal electrolyte nanoscale-reservoirs, the device exhibited good electrochemical performance (about 1.73 mF cm-2), and a transmittance of about 56% (at 550 nm).Paper-based transparent flexible thin film supercapacitors were fabricated using CNF-[RGO]n hybrid paper as an electrode material and charge collector. Owing to the self-anti-stacking of distorted RGO nanosheets and internal electrolyte nanoscale-reservoirs, the device exhibited good electrochemical performance (about 1.73 mF cm-2), and a transmittance of about 56% (at 550 nm). Electronic supplementary information (ESI) available: Experimental, TEM image, IR spectra, and XRD spectra of cellulose nanofibers, TEM image, and XRD spectra of RGO, graphite, GO nanosheets, CNF paper, and CNF-[RGO]20 hybrid paper, high-resolution C1s spectra of GO, Raman spectra of GO nanosheets, cross-sectional FESEM image of CNF-[RGO]20 hybrid paper and stress-strain curve of T-SC-20. See DOI: 10.1039/c3nr00674c

Structural, dielectric and ferroelectric characterization of PZT thin films

Directory of Open Access Journals (Sweden)

Araújo E.B.

1999-01-01

Full Text Available In this work ferroelectric thin films of PZT were prepared by the oxide precursor method, deposited on Pt/Si substrate. Films of 0.5 mm average thickness were obtained. Electrical and ferroelectric characterization were carried out in these films. The measured value of the dielectric constant for films was 455. Ferroelectricity was confirmed by Capacitance-Voltage (C-V characteristics and P-E hysteresis loops. Remanent polarization for films presented value around 5.0 µC/cm2 and a coercive field of 88.8 kV/cm.

Effect of annealing temperature on optical and electrical properties of metallophthalocyanine thin films deposited on silicon substrate

Directory of Open Access Journals (Sweden)

Skonieczny R.

2016-09-01

Full Text Available The cobalt phthalocyanine (CoPc thin films (300 nm thick deposited on n-type silicon substrate have been studied using micro-Raman spectroscopy, atomic force spectroscopy (AFM and I-V measurement. The CoPc thin layers have been deposited at room temperature by the quasi-molecular beam evaporation technique. The micro-Raman spectra of CoPc thin films have been recorded in the spectral range of 1000 cm-1 to 1900 cm-1 using 488 nm excitation wavelength. Moreover, using surface Raman mapping it was possible to obtain information about polymorphic forms distribution (before and after annealing of metallophthalocyanine (α and β form from polarized Raman spectra. The I-V characteristics of the Au/CoPc/n-Si/Al Schottky barrier were also investigated. The obtained results showed that influence of the annealing process plays a crucial role in the ordering and electrical conductivity of the molecular structure of CoPc thin films deposited on n-type silicon substrate.

Optoelectronic properties of R-F magnetron sputtered Cadmium Tin Oxide (Cd2SnO4) thin films for CdS/CdTe thin film solar cell applications

International Nuclear Information System (INIS)

Jeyadheepan, K.; Thamilselvan, M.; Kim, Kyunghae; Yi, Junsin; Sanjeeviraja, C.

2015-01-01

Highlights: • Characterization of “as-prepared” Cd 2 SnO 4 thin films ideal for thin film solar cells. • Lowest value of resistivity with high mobility attained for the as-prepared Cd 2 SnO 4 films. • Maximum transmittance of 93% in the visible range for the as-prepared films. • Effect of substrate temperature on the scattering mechanism of TCO. - Abstract: The influence of substrate temperature on the microstructural behavior, optical, electrical properties and on the scattering mechanism of charge carriers were studied for the as-prepared radio-frequency (R-F) magnetron sputtered Cadmium Tin Oxide (Cd 2 SnO 4 ) thin films. Films prepared at the substrate temperature of 300 °C were found to be polycrystalline in nature with preferential orientation along (3 1 1) plane. Well pronounced Moss–Burstein shift, in the transmittance spectra with dispersions in the optical band gap from 3.07 to 3.30 eV, was observed at substrate temperatures between 25 and 300 °C. Optical property of high visible transmittance was retained by the films. Analysis of the electrical properties on the prepared crystalline Cd 2 SnO 4 films showed a calculated resistivity of 10 −3 –10 −4 Ω cm, with n-type carrier density in the range of 10 19 –10 20 cm −3 and the charge carrier mobility in the range of 63–30 cm 2 /V s. The effects of structural, compositional and optical properties on the scattering mechanism of charge carrier are elaborated and reported to be an experimental evidence for the theoretical predictions. The results revealed the essential DC electrical conduction behavior, which is ideal for the fabrication of Cd 2 SnO 4 -based CdS/CdTe thin film solar cells

The use of thin-section high-resolution CT in pediatric pulmonary disease

International Nuclear Information System (INIS)

Hay, T.C.; Horgan, J.G.; Rumack, C.M.

1989-01-01

High-resolution thin-section CT of the chest was used successfully to characterize the extent of pulmonary disease. This paper reports on a study in which ten children with chronic lung disorders (including cystic fibrosis, reactive airway disease, and idiopathic disease) were evaluated to test the accuracy of the posteroanterior and lateral chest CT, with both thick (1 cm) and thin (1-3 mm) sections. Unsuspected bronchiectasis was established n two patients with reactive airway disease, and the extent of bronchiectasis in other patients was best defined on thin-section CT. Technique was crucial for an accurate study, and magnification views of each lung were useful. Thin-section CT of the chest was helpful in defining and localizing the extent of these pulmonary disorders

Growth of Cu2ZnSnS4(CZTS) by Pulsed Laser Deposition for Thin film Photovoltaic Absorber Material

Science.gov (United States)

Nandur, Abhishek; White, Bruce

2014-03-01

CZTS (Cu2ZnSnS4) has become the subject of intense interest because it is an ideal candidate absorber material for thin-film solar cells with an optimal band gap (1.5 eV), high absorption coefficient (104 cm-1) and abundant elemental components. Pulsed Laser Deposition (PLD) provides excellent control over film composition since thin films are deposited under high vacuum with excellent stoichiometry transfer from the target. CZTS thin films were deposited using PLD from a stoichiometrically close CZTS target (Cu2.6Zn1.1Sn0.7S3.44). The effects of laser energy fluence and substrate temperature and post-deposition sulfur annealing on the surface morphology, composition and optical absorption have been investigated. Optimal CZTS thin films exhibited a band gap of 1.54 eV with an absorption coefficient of 4x104cm-1. A solar cell utilizing PLD grown CZTS with the structure SLG/Mo/CZTS/CdS/ZnO/ITO showed a conversion efficiency of 5.85% with Voc = 376 mV, Jsc = 38.9 mA/cm2 and Fill Factor, FF = 0.40.

Correlations Among Microstructure, Morphology, Chemistry, and Isotopic Systematics of Hibonite in CM Chondrites

Science.gov (United States)

Han, J.; Liu, M.-C..; Keller, L. P.; Davis, A. M.

2017-01-01

Introduction: Hibonite is a primary refractory phase occurring in many CAIs, typically with spinel and perovskite. Our microstructural studies of CAIs from carbonaceous chondrites reveal a range of stacking defect densities and correlated non-stoichiometry in hibonite. We also conducted a series of annealing experiments, demonstrating that the Mg-Al substitution stabilized the formation of defect-structured hibonite. Here, we continue a detailed TEM analysis of hibonite-bearing inclusions from CM chondrites that have been well-characterized isotopically. We examine possible correlations of microstructure, morphology, mineralogy, and chemical and isotopic systematics of CM hibonites in order to better understand the formation history of hibonite in the early solar nebula. Methods: Fifteen hibonite-bearing inclusions from the Paris CM chondrite were analyzed using a JEOL 7600F SEM and a JEOL 8530F electron microprobe. In addition to three hibonite-bearing inclusions from the Murchison CM chondrite previously reported, we selected three inclusions from Paris, Pmt1-6, 1-9, and 1-10, representing a range of 26Al/27Al ratios and minor element concentrations for a detailed TEM study. We extracted TEM sections from hibonite grains using a FEI Quanta 3D field emission gun SEM/FIB. The sections were then examined using a JEOL 2500SE field-emission scanning TEM equipped with a Thermo-Noran thin window EDX spectrometer. Results and Discussion: A total of six hibonite-bearing inclusions, including two platy hibonite crystals (PLACs) and four spinel-hibonite inclusions (SHIBs), were studied. There are notable differences in chemical and isotopic compositions between the inclusions (Table 1), indicative of their different formation environment or timing. Our TEM observations show perfectly-ordered, stoichiometric hibonite crystals without stacking defects in two PLACs, 2-7-1 and 2-8-2, and in three SHIBs, Pmt1-6, 1-9, and 1-10. In contrast, SHIB 1-9-5 hibonite grains contain a

Charged thin-shell gravastars in noncommutative geometry

Energy Technology Data Exchange (ETDEWEB)

Oevguen, Ali [Pontificia Universidad Catolica de Valparaiso, Instituto de Fisica, Valparaiso (Chile); Eastern Mediterranean University, Physics Department, Famagusta, Northern Cyprus (Turkey); Banerjee, Ayan [Jadavpur University, Department of Mathematics, Kolkata, West Bengal (India); Jusufi, Kimet [State University of Tetovo, Physics Department, Tetovo (Macedonia, The Former Yugoslav Republic of); Institute of Physics, Ss. Cyril and Methodius University, Faculty of Natural Sciences and Mathematics, Skopje (Macedonia, The Former Yugoslav Republic of)

2017-08-15

In this paper we construct a charged thin-shell gravastar model within the context of noncommutative geometry. To do so, we choose the interior of the nonsingular de Sitter spacetime with an exterior charged noncommutative solution by cut-and-paste technique and apply the generalized junction conditions. We then investigate the stability of a charged thin-shell gravastar under linear perturbations around the static equilibrium solutions as well as the thermodynamical stability of the charged gravastar. We find the stability regions, by choosing appropriate parameter values, located sufficiently close to the event horizon. (orig.)

Comparison of structural properties of thermally evaporated CdTe thin films on different substrates

International Nuclear Information System (INIS)

Tariq, G.H.; Anis-ur-Rehman, M.

2011-01-01

The direct energy band gap in the range of 1.5 eV and the high absorption coefficient (105 cm/sup -1/) makes Cadmium Telluride (CdTe) a suitable material for fabrication of thin film solar cells. Thin film solar cells based on CdTe (1 cm area) achieved efficiency of 15.6% on a laboratory scale. CdTe thin films were deposited by thermal evaporation technique under vacuum 2 X 10/sup -5/mbar on glass and stainless steel (SS) substrates. During deposition substrates temperature was kept same at 200 deg. C for all samples. The structural properties were determined by the X-ray Diffraction (XRD) patterns. All samples exhibit polycrystalline nature. Dependence of different structural parameters such as lattice parameter, micro strain, and grain size and dislocation density on thickness was studied. Also the influence of the different substrates on these parameters was investigated. The analysis showed that the preferential orientation of films was dependent on the substrate type. (author)

Pulsed laser deposition of piezoelectric lead zirconate titanate thin films maintaining a post-CMOS compatible thermal budget

Science.gov (United States)

Schatz, A.; Pantel, D.; Hanemann, T.

2017-09-01

Integration of lead zirconate titanate (Pb[Zrx,Ti1-x]O3 - PZT) thin films on complementary metal-oxide semiconductor substrates (CMOS) is difficult due to the usually high crystallization temperature of the piezoelectric perovskite PZT phase, which harms the CMOS circuits. In this work, a wafer-scale pulsed laser deposition tool was used to grow 1 μm thick PZT thin films on 150 mm diameter silicon wafers. Three different routes towards a post-CMOS compatible deposition process were investigated, maintaining a post-CMOS compatible thermal budget limit of 445 °C for 1 h (or 420 °C for 6 h). By crystallizing the perovskite LaNiO3 seed layer at 445 °C, the PZT deposition temperature can be lowered to below 400 °C, yielding a transverse piezoelectric coefficient e31,f of -9.3 C/m2. With the same procedure, applying a slightly higher PZT deposition temperature of 420 °C, an e31,f of -10.3 C/m2 can be reached. The low leakage current density of below 3 × 10-6 A/cm2 at 200 kV/cm allows for application of the post-CMOS compatible PZT thin films in low power micro-electro-mechanical-systems actuators.

Studies on the high electronic energy deposition in polyaniline thin films

International Nuclear Information System (INIS)

Deshpande, N.G.; Gudage, Y.G.; Vyas, J.C.; Singh, F.; Sharma, Ramphal

2008-01-01

We report here the physico-chemical changes brought about by high electronic energy deposition of gold ions in HCl doped polyaniline (PANI) thin films. PANI thin films were synthesized by in situ polymerization technique. The as-synthesized PANI thin films of thickness 160 nm were irradiated using Au 7+ ion of 100 MeV energy at different fluences, namely, 5 x 10 11 ions/cm 2 and 5 x 10 12 ions/cm 2 , respectively. A significant change was seen after irradiation in electrical and photo conductivity, which may be related to increased carrier concentration, and structural modifications in the polymer film. In addition, the high electronic energy deposition showed other effects like cross-linking of polymer chains, bond breaking and creation of defect sites. AFM observations revealed mountainous type features in all (before and after irradiation) PANI samples. The average size (diameter) and density of such mountainous clusters were found to be related with the ion fluence. The AFM profiles also showed change in the surface roughness of the films with respect to irradiation, which is one of the peculiarity of the high electronic energy deposition technique

Silicon surface passivation using thin HfO2 films by atomic layer deposition

International Nuclear Information System (INIS)

Gope, Jhuma; Vandana; Batra, Neha; Panigrahi, Jagannath; Singh, Rajbir; Maurya, K.K.; Srivastava, Ritu; Singh, P.K.

2015-01-01

Graphical abstract: - Highlights: • HfO 2 films using thermal ALD are studied for silicon surface passivation. • As-deposited thin film (∼8 nm) shows better passivation with surface recombination velocity (SRV) <100 cm/s. • Annealing improves passivation quality with SRV ∼20 cm/s for ∼8 nm film. - Abstract: Hafnium oxide (HfO 2 ) is a potential material for equivalent oxide thickness (EOT) scaling in microelectronics; however, its surface passivation properties particularly on silicon are not well explored. This paper reports investigation on passivation properties of thermally deposited thin HfO 2 films by atomic layer deposition system (ALD) on silicon surface. As-deposited pristine film (∼8 nm) shows better passivation with <100 cm/s surface recombination velocity (SRV) vis-à-vis thicker films. Further improvement in passivation quality is achieved with annealing at 400 °C for 10 min where the SRV reduces to ∼20 cm/s. Conductance measurements show that the interface defect density (D it ) increases with film thickness whereas its value decreases after annealing. XRR data corroborate with the observations made by FTIR and SRV data.

Solution coating of large-area organic semiconductor thin films with aligned single-crystalline domains

KAUST Repository

Diao, Ying

2013-06-02

Solution coating of organic semiconductors offers great potential for achieving low-cost manufacturing of large-area and flexible electronics. However, the rapid coating speed needed for industrial-scale production poses challenges to the control of thin-film morphology. Here, we report an approach - termed fluid-enhanced crystal engineering (FLUENCE) - that allows for a high degree of morphological control of solution-printed thin films. We designed a micropillar-patterned printing blade to induce recirculation in the ink for enhancing crystal growth, and engineered the curvature of the ink meniscus to control crystal nucleation. Using FLUENCE, we demonstrate the fast coating and patterning of millimetre-wide, centimetre-long, highly aligned single-crystalline organic semiconductor thin films. In particular, we fabricated thin films of 6,13-bis(triisopropylsilylethynyl) pentacene having non-equilibrium single-crystalline domains and an unprecedented average and maximum mobilities of 8.1±1.2 cm2 V-1 s -1 and 11 cm2 V-1 s-1. FLUENCE of organic semiconductors with non-equilibrium single-crystalline domains may find use in the fabrication of high-performance, large-area printed electronics. © 2013 Macmillan Publishers Limited. All rights reserved.

The effect of Nb doping on ferroelectric properties of PZT thin films prepared from polymeric precursors

International Nuclear Information System (INIS)

Souza, E.C.F.; Simoes, A.Z.; Cilense, M.; Longo, E.; Varela, J.A.

2004-01-01

Pure and Nb doped PbZr 0.4 Ti 0.6 O 3 thin films was prepared by the polymeric precursor method and deposited by spin coating on Pt/Ti/SiO 2 /Si (100) substrates and annealed at 700 deg. C. The films are oriented in (1 1 0) and (1 0 0) direction. The electric properties of PZT thin films show strong dependence of the crystallographic orientation. The P-E hysteresis loops for the thin film with composition PbZr 0.39 Ti 0.6 Nb 0.1 O 3 showed good saturation, with values for coercive field (E c ) equal to 60 KV cm -1 and for remanent polarization (P r ) equal to 20 μC cm -2 . The measured dielectric constant (ε) is 1084 for this film. These results show good potential for application in FERAM

Resistivity scaling due to electron surface scattering in thin metal layers

Science.gov (United States)

Zhou, Tianji; Gall, Daniel

2018-04-01

The effect of electron surface scattering on the thickness-dependent electrical resistivity ρ of thin metal layers is investigated using nonequilibrium Green's function density functional transport simulations. Cu(001) thin films with thickness d =1 -2 nm are used as a model system, employing a random one-monolayer-high surface roughness and frozen phonons to cause surface and bulk scattering, respectively. The zero-temperature resistivity increases from 9.7 ±1.0 μ Ω cm at d =1.99 nm to 18.7 ±2.6 μ Ω cm at d =0.9 0 nm, contradicting the asymptotic T =0 prediction from the classical Fuchs-Sondheimer model. At T =9 00 K, ρ =5.8 ±0.1 μ Ω cm for bulk Cu and ρ =13.4 ±1.1 and 22.5 ±2.4 μ Ω cm for layers with d =1.99 and 0.90 nm, respectively, indicating an approximately additive phonon contribution which, however, is smaller than for bulk Cu or atomically smooth layers. The overall data indicate that the resistivity contribution from surface scattering is temperature-independent and proportional to 1 /d , suggesting that it can be described using a surface-scattering mean-free path λs for 2D transport which is channel-independent and proportional to d . Data fitting indicates λs=4 ×d for the particular simulated Cu(001) surfaces with a one-monolayer-high surface roughness. The 1 /d dependence deviates considerably from previous 1 /d2 predictions from quantum models, indicating that the small-roughness approximation in these models is not applicable to very thin (<2 nm) layers, where the surface roughness is a considerable fraction of d .

Hydrogen irradiation on TiO{sub 2} nano-thin films

Energy Technology Data Exchange (ETDEWEB)

Heidari, Sh.; Mohammadizadeh, M.R. [University of Tehran, Superconductivity Research Laboratory (SRL), Department of Physics, Tehran (Iran, Islamic Republic of); Mahjour-Shafiei, M. [University of Tehran, Department of Physics, Tehran (Iran, Islamic Republic of); Larijani, M.M.; Malek, M. [Science and Technology Research Institute, Agricultural, Medical and Industrial Research School, Karaj (Iran, Islamic Republic of)

2015-10-15

Titanium dioxide thin films were coated on soda-lime glass substrates using spray pyrolysis method with a thickness of 152 ± 10 nm. The films were irradiated with hydrogen ions at room temperature at various beam energies and fluences. Optimized incident beam energy and beam fluence were obtained to improve photocatalytic and hydrophilicity properties of TiO{sub 2} thin films by narrowing the band gap. Samples were characterized by scanning electron microscopy to study the surface morphology and by UV-Vis absorption spectroscopy to measure the band gap. The optical band gap of H-doped anatase TiO{sub 2} thin films irradiated with hydrogen beam with energies of 2 and 4 keV and a fluence of 10{sup 15} ions/cm{sup 2} was narrowed from 3.34 eV (before irradiation) to 3.04 and 2.92 eV (after irradiation), respectively. The irradiated sample with energy of 4 keV with a fluence of 10{sup 15} ions/cm{sup 2} has the best improvement. This is attributed to the contraction of the band gap and to the increase in surface active site. Furthermore, it was observed that photocatalytic and hydrophilicity properties of this sample were improved, as well. (orig.)

Investigations on Important Properties of the 10 cm x 10 cm GEM Prototype

CERN Document Server

Saenboonruang, Kiadtisak; Kulasri, Kittipong; Ritthirong, Anawat

2015-01-01

The Gas Electron Multiplier (GEM) detector is one of promising particle and radiation detectors that has been improved greatly from previous gas detectors. The improvement includes better spatial resolutions, higher detection rate capabilities, and flexibilities in designs. In particular, the 10 cm x 10 cm GEM prototype is designed and provided by the Gas Detectors Development group (GDD) at CERN, Switzerland. With its simplicity in operations and designs, while still maintaining high qualities, the GEM prototype is suitable for both start-up and advanced researches. This article aims to report the investigations on some important properties of the 10 cm x 10 cm GEM detector using current measurement and signal counting. Results have shown that gains of the GEM prototype exponentially increase as voltage supplied to the detector increases, while the detector reaches full efficiency (plateau region) when the voltage is greater than 4100 V. In terms of signal sharing between X and Y strips of the readout, X str...

A 0.18 micrometer CMOS Thermopile Readout ASIC Immune to 50 MRAD Total Ionizing Dose (SI) and Single Event Latchup to 174MeV-cm(exp 2)/mg

Science.gov (United States)

Quilligan, Gerard T.; Aslam, Shahid; Lakew, Brook; DuMonthier, Jeffery J.; Katz, Richard B.; Kleyner, Igor

2014-01-01

Radiation hardened by design (RHBD) techniques allow commercial CMOS circuits to operate in high total ionizing dose and particle fluence environments. Our radiation hard multi-channel digitizer (MCD) ASIC (Figure 1) is a versatile analog system on a chip (SoC) fabricated in 180nm CMOS. It provides 18 chopper stabilized amplifier channels, a 16- bit sigma-delta analog-digital converter (SDADC) and an on-chip controller. The MCD was evaluated at Goddard Space Flight Center and Texas A&M University's radiation effects facilities and found to be immune to single event latchup (SEL) and total ionizing dose (TID) at 174 MeV-cm(exp 2)/mg and 50 Mrad (Si) respectively.

Effects of electron irradiation and temperature on 1 ohm-cm and 10 ohm-cm silicon solar cells

Science.gov (United States)

Nicoletta, C. A.

1973-01-01

One OHM-cm and 10 OHM-cm silicon solar cells were exposed to 1.0 MeV electrons at a fixed flux of 10 to the 11th power e/sq cm/sec and fluences of 10 to the 13th power, 10 to the 14th power and 10 to the 15th power e/sq.cm. 1-V curves of the cells were made at room temperature, - 63 C and + or - 143 C after each irradiation. A value of 139.5 mw/sq cm was used as AMO incident energy rate per unit area. The 10 OHM-cm cells appear more efficient than 1 OHM-cm cells after exposure to a fluence greater than 10 to the 14th power e/sq cm. The 1.0 MeV electron damage coefficients for both 1 OHM-cm and 10 OHM-cm cells are somewhat less than those for previously irradiated cells at room temperature. The values of the damage coefficients increase as the cell temperatures decrease. Efficiencies pertaining to maximum power output are about the same as those of n on p silicon cells evaluated previously.

Seebeck effect of some thin film carbides

International Nuclear Information System (INIS)

Beensh-Marchwicka, G.; Prociow, E.

2002-01-01

Several materials have been investigated for high-temperature thin film thermocouple applications. These include silicon carbide with boron (Si-C-B), ternary composition based on Si-C-Mn, fourfold composition based on Si-C-Zr-B and tantalum carbide (TaC). All materials were deposited on quartz or glass substrates using the pulse sputter deposition technique. Electrical conduction and thermoelectric power were measured for various compositions at 300-550 K. It has been found, that the efficiency of thermoelectric power of films containing Si-C base composition was varied from 0.0015-0.034 μW/cmK 2 . However for TaC the value about 0.093 μW/cmK 2 was obtained. (author)

Experimental study of Pulsed Laser Deposited Cu2ZnSnS 4 (CZTS) thin films for photovoltaic applications

Science.gov (United States)

Nandur, Abhishek S.

Thin film solar cells are gaining momentum as a renewable energy source. Reduced material requirements (15 mum in total thickness) solar cells. Among the various thin film solar absorbers that have been proposed, CZTS (Cu2ZnSnS4) has become the subject of intense interest because of its optimal band gap (1.45 eV), high absorption coefficient (104 cm--1 ) and abundant elemental components. Pulsed Laser Deposition (PLD) provides excellent control over film composition since films are deposited under high vacuum with excellent stoichiometry transfer from the target. Defect-free, near-stoichiometric poly-crystalline CZTS thin films were deposited using PLD from a stoichiometrically close CZTS target (Cu2.6Zn1.1Sn0.7S3.44). The effects of fabrication parameters such as laser energy density, deposition time, substrate temperature and sulfurization (annealing in sulfur) on the surface morphology, composition and optical absorption of the CZTS thin films were examined. The results show that the presence of secondary phases, present both in the bulk and on the surface, affected the electrical and optical properties of the CZTS thin films and the CZTS based TFSCs. After selectively etching away the secondary phases with DIW, HCl and KCN, it was observed that their removal improved the performance of CZTS based TFSCs. Optimal CZTS thin films exhibited an optical band gap of 1.54 eV with an absorption coefficient of 4x10 4cm-1 with a low volume of secondary phases. A TFSC fabricated with the best CZTS thin film obtained from the experimental study done in this thesis showed a conversion efficiency of 6.41% with Voc = 530 mV, Jsc= 27.5 mA/cm2 and a fill factor of 0.44.

ZnS nanostructured thin-films deposited by successive ionic layer adsorption and reaction

Science.gov (United States)

Deshmukh, S. G.; Jariwala, Akshay; Agarwal, Anubha; Patel, Chetna; Panchal, A. K.; Kheraj, Vipul

2016-04-01

ZnS thin films were grown on glass substrate using successive ionic layer adsorption and reaction (SILAR) technique at room temperature. Aqueous solutions of ZnCl2 and Na2S were used as precursors. The X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Raman spectroscopy and optical absorption measurements were applied to study the structural, surface morphology and optical properties of as-deposited ZnS thin films. The X-ray diffraction profiles revealed that ZnS thin films consist of crystalline grains with cubic phase. Spherical nano grains of random size and well covered on the glass substrate were observed from FESEM. The average grain size were found to be 77 nm, 100 nm and 124 nm for 20 cycles, 40 cycles and 60 cycles samples respectively. For 60 cycle sample, Raman spectra show two prominent peaks at 554 cm-1 and 1094 cm-1. The optical band gap values were found to be 3.76 eV, 3.72 eV and 3.67 eV for 20 cycle, 40 cycle and 60 cycle samples respectively.

Effects of proton irradiation and temperature on 1 ohm-cm and 10 ohm-cm silicon solar cells

Science.gov (United States)

Nicoletta, C. A.

1973-01-01

The 1 ohm-cm and 10 ohm-cm silicon solar cells were exposed to 1.0 MeV protons at a fixed flux of 10 to the 9th power P/sq cm-sec and fluences of 10 to the 10th power, 10 to the 11th power, 10 to the 12th power and 3 X 10 to the 12th power P/sq cm. I-V curves of the cells were made at room temperature, 65 C and 165 C after each irradiation. A value of 139.5 mw/sq cm was taken as AMO incident energy rate per unit area. Degradation occurred for both uncovered 1 ohm-cm and 10 ohm-cm cells. Efficiencies are generally higher than those of comparable U.S. cells tested earlier. Damage (loss in maximum power efficiency) with proton fluence is somewhat higher for 10 ohm-cm cells, measured at the three temperatures, for fluences above 2 X 10 to the 11th power P/sq cm. Cell efficiency, as expected, changes drastically with temperature.

A comparative study of physico-chemical properties of CBD and SILAR grown ZnO thin films

Energy Technology Data Exchange (ETDEWEB)

Jambure, S.B.; Patil, S.J.; Deshpande, A.R.; Lokhande, C.D., E-mail: l_chandrakant@yahoo.com

2014-01-01

Graphical abstract: Schematic model indicating ZnO nanorods by CBD (Z{sub 1}) and nanograins by SILAR (Z{sub 2}). - Highlights: • Simple methods for the synthesis of ZnO thin films. • Comparative study of physico-chemical properties of ZnO thin films prepared by CBD and SILAR methods. • CBD outperforms SILAR method. - Abstract: In the present work, nanocrystalline zinc oxide (ZnO) thin films have been successfully deposited onto glass substrates by simple and economical chemical bath deposition (CBD) and successive ionic layer adsorption reaction (SILAR) methods. These films were further characterized for their structural, optical, surface morphological and wettability properties. The X-ray diffraction (XRD) patterns for both CBD and SILAR deposited ZnO thin films reveal the highly crystalline hexagonal wurtzite structure. From optical studies, band gaps obtained are 2.9 and 3.0 eV for CBD and SILAR deposited thin films, respectively. The scanning electron microscope (SEM) patterns show growth of well defined randomly oriented nanorods and nanograins on the CBD and SILAR deposited samples, respectively. The resistivity of CBD deposited films (10{sup 2} Ω cm) is lower than that of SILAR deposited films (10{sup 5} Ω cm). Surface wettability studies show hydrophobic nature for both films. From the above results it can be concluded that CBD grown ZnO thin films show better properties as compared to SILAR method.

A comparative study of physico-chemical properties of CBD and SILAR grown ZnO thin films

International Nuclear Information System (INIS)

Jambure, S.B.; Patil, S.J.; Deshpande, A.R.; Lokhande, C.D.

2014-01-01

Graphical abstract: Schematic model indicating ZnO nanorods by CBD (Z 1 ) and nanograins by SILAR (Z 2 ). - Highlights: • Simple methods for the synthesis of ZnO thin films. • Comparative study of physico-chemical properties of ZnO thin films prepared by CBD and SILAR methods. • CBD outperforms SILAR method. - Abstract: In the present work, nanocrystalline zinc oxide (ZnO) thin films have been successfully deposited onto glass substrates by simple and economical chemical bath deposition (CBD) and successive ionic layer adsorption reaction (SILAR) methods. These films were further characterized for their structural, optical, surface morphological and wettability properties. The X-ray diffraction (XRD) patterns for both CBD and SILAR deposited ZnO thin films reveal the highly crystalline hexagonal wurtzite structure. From optical studies, band gaps obtained are 2.9 and 3.0 eV for CBD and SILAR deposited thin films, respectively. The scanning electron microscope (SEM) patterns show growth of well defined randomly oriented nanorods and nanograins on the CBD and SILAR deposited samples, respectively. The resistivity of CBD deposited films (10 2 Ω cm) is lower than that of SILAR deposited films (10 5 Ω cm). Surface wettability studies show hydrophobic nature for both films. From the above results it can be concluded that CBD grown ZnO thin films show better properties as compared to SILAR method

Investigation of SiO2 thin films dielectric constant using ellipsometry technique

Directory of Open Access Journals (Sweden)

P Sangpour

2014-11-01

Full Text Available In this paper, we studied the optical behavior of SiO2 thin films prepared via sol-gel route using spin coating deposition from tetraethylorthosilicate (TEOS as precursor. Thin films were annealed at different temperatures (400-600oC. Absorption edge and band gap of thin layers were measured using UV-Vis spectrophotometery. Optical refractive index and dielectric constant were measured by ellipsometry technique. Based on our atomic force microscopic (AFM and ellipsometry results, thin layers prepared through this method showed high surface area, and high porosity ranging between 4.9 and 16.9, low density 2 g/cm, and low dielectric constant. The dielectric constant and porosity of layers increased by increasing the temperature due to the changes in surface roughness and particle size.

Highly Yb-doped KGd(WO4)2 thin-film amplifier

NARCIS (Netherlands)

Yong, Yean Sheng; Aravazhi, S.; Vázquez-Córdova, Sergio Andrés; García Blanco, Sonia Maria; Pollnau, Markus

We report record-high small-signal gain of 1050 dB/cm at 981 nm wavelength in a KGd0.425Yb0.575(WO4)2 thin film. The sensitivity of gain to the shift of beam-focus position, which is critical under non-waveguiding conditions, is investigated.

Direct growth of superconducting NdFeAs(O,F) thin films by MBE

Energy Technology Data Exchange (ETDEWEB)

Chihara, Masashi, E-mail: chihara@iku.xtal.nagoya-u.ac.jp [Department of Crystalline Materials Science, Nagoya University, Chikusa-ku, Nagoya 464-8603 (Japan); Sumiya, Naoki; Arai, Kenta [Department of Crystalline Materials Science, Nagoya University, Chikusa-ku, Nagoya 464-8603 (Japan); Ichinose, Ataru; Tsukada, Ichiro [Central Research Institute of Electric Power Industry, Yokosuka-shi, Kanagawa 240-0101 (Japan); Hatano, Takafumi; Iida, Kazumasa; Ikuta, Hiroshi [Department of Crystalline Materials Science, Nagoya University, Chikusa-ku, Nagoya 464-8603 (Japan)

2015-11-15

Highlights: • Highly textured NdFeAs(O,F) thin films were obtained by a direct growth method. • Enhancing the migration was crucial to realize the direct growth. • The critical current density exceeded 3 MA/cm{sup 2} at self-field and 1 MA/cm{sup 2} at 9 T. • A two-dimensional growth was confirmed by the observation of surface morphology. - Abstract: We report on the growth of NdFeAs(O,F) superconducting thin films by molecular beam epitaxy without having a NdOF secondary layer that was necessary for fluorine doping in our previous studies. The key to realizing the direct growth of a superconducting film was the enhancement of migration of the raw materials on the substrate, which was accomplished by two steps. Firstly, we increased the growth temperature that improved the crystalline quality of parent NdFeAsO thin films. Secondly, the atmosphere in the chamber during the growth was improved by changing the crucible material of the Fe source cell. Highly textured NdFeAs(O,F) thin films with critical temperatures up to 50 K were obtained, and terraces were observed by atomic force microscope, indicating a two-dimensional growth. However, precipitates were also found on the surface, which suggests that enhancing further the migration is necessary for obtaining a NdFeAs(O,F) thin film with a better quality.

Ultrahigh Flux Thin Film Boiling Heat Transfer Through Nanoporous Membranes.

Science.gov (United States)

Wang, Qingyang; Chen, Renkun

2018-05-09

Phase change heat transfer is fundamentally important for thermal energy conversion and management, such as in electronics with power density over 1 kW/cm 2 . The critical heat flux (CHF) of phase change heat transfer, either evaporation or boiling, is limited by vapor flux from the liquid-vapor interface, known as the upper limit of heat flux. This limit could in theory be greater than 1 kW/cm 2 on a planar surface, but its experimental realization has remained elusive. Here, we utilized nanoporous membranes to realize a new "thin film boiling" regime that resulted in an unprecedentedly high CHF of over 1.2 kW/cm 2 on a planar surface, which is within a factor of 4 of the theoretical limit, and can be increased to a higher value if mechanical strength of the membranes can be improved (demonstrated with 1.85 kW/cm 2 CHF in this work). The liquid supply is achieved through a simple nanoporous membrane that supports the liquid film where its thickness automatically decreases as heat flux increases. The thin film configuration reduces the conductive thermal resistance, leads to high frequency bubble departure, and provides separate liquid-vapor pathways, therefore significantly enhances the heat transfer. Our work provides a new nanostructuring approach to achieve ultrahigh heat flux in phase change heat transfer and will benefit both theoretical understanding and application in thermal management of high power devices of boiling heat transfer.

Enhanced electrical properties in solution-processed InGaZnO thin-film transistors by viable hydroxyl group transfer process

Science.gov (United States)

Kim, Do-Kyung; Jeong, Hyeon-Seok; Kwon, Hyeok Bin; Kim, Young-Rae; Kang, Shin-Won; Bae, Jin-Hyuk

2018-05-01

We propose a simple hydroxyl group transfer method to improve the electrical characteristics of solution-processed amorphous InGaZnO (IGZO) thin-film transistors (TFTs). Tuned poly(dimethylsiloxane) elastomer, which has a hydroxyl group as a terminal chemical group, was adhered temporarily to an IGZO thin-film during the solidification step to transfer and supply sufficient hydroxyl groups to the IGZO thin-film. The transferred hydroxyl groups led to efficient hydrolysis and condensation reactions, resulting in a denser metal–oxygen–metal network being achieved in the IGZO thin-film compared to the conventional IGZO thin-film. In addition, it was confirmed that there was no morphological deformation, including to the film thickness and surface roughness. The hydroxyl group transferred IGZO based TFTs exhibited enhanced electrical properties (field-effect mobility of 2.21 cm2 V‑1 s‑1, and on/off current ratio of 106) compared to conventional IGZO TFTs (field-effect mobility of 0.73 cm2 V‑1 s‑1 and on/off current ratio of 105).

Functionalized porphyrin conjugate thin films deposited by matrix assisted pulsed laser evaporation

Energy Technology Data Exchange (ETDEWEB)

Iordache, S. [University of Bucharest, 3Nano-SAE Research Center, PO Box MG-38, Bucharest-Magurele (Romania); Cristescu, R., E-mail: rodica.cristescu@inflpr.ro [National Institute for Lasers, Plasma and Radiation Physics, Lasers Department, P.O. Box MG-36, Bucharest-Magurele (Romania); Popescu, A.C.; Popescu, C.E.; Dorcioman, G.; Mihailescu, I.N. [National Institute for Lasers, Plasma and Radiation Physics, Lasers Department, P.O. Box MG-36, Bucharest-Magurele (Romania); Ciucu, A.A. [University of Bucharest, Faculty of Chemistry, Bucharest (Romania); Balan, A.; Stamatin, I. [University of Bucharest, 3Nano-SAE Research Center, PO Box MG-38, Bucharest-Magurele (Romania); Fagadar-Cosma, E. [Institute of Chemistry Timisoara of Romanian Academy, M. Viteazul Ave. 24, 300223-Timisoara (Romania); Chrisey, D.B. [Tulane University, Departments of Physics and Biomedical Engineering, New Orleans, LA 70118 (United States)

2013-08-01

We report on the deposition of nanostructured porphyrin-base, 5(4-carboxyphenyl)-10,15,20-tris(4-phenoxyphenyl)-porphyrin thin films by matrix assisted pulsed laser evaporation onto silicon substrates with screen-printed electrodes. AFM investigations have shown that at 400 mJ/cm{sup 2} fluence a topographical transition takes place from the platelet-like stacking porphyrin-based nanostructures in a perpendicular arrangement to a quasi-parallel one both relative to the substrate surface. Raman spectroscopy has shown that the chemical structure of the deposited thin films is preserved for fluences within the range of 200–300 mJ/cm{sup 2}. Cyclic voltammograms have demonstrated that the free porphyrin is appropriate as a single mediator for glucose in a specific case of screen-printed electrodes, suggesting potential for designing a new class of biosensors.

Short-Term Belowground Responses to Thinning and Burning Treatments in Southwestern Ponderosa Pine Forests of the USA

Directory of Open Access Journals (Sweden)

Steven T. Overby

2016-02-01

Full Text Available Microbial-mediated decomposition and nutrient mineralization are major drivers of forest productivity. As landscape-scale fuel reduction treatments are being implemented throughout the fire-prone western United States of America, it is important to evaluate operationally how these wildfire mitigation treatments alter belowground processes. We quantified these important belowground components before and after management-applied fuel treatments of thinning alone, thinning combined with prescribed fire, and prescribed fire in ponderosa pine (Pinus ponderosa stands at the Southwest Plateau, Fire and Fire Surrogate site, Arizona. Fuel treatments did not alter pH, total carbon and nitrogen (N concentrations, or base cations of the forest floor (O horizon or mineral soil (0–5 cm during this 2-year study. In situ rates of net N mineralization and nitrification in the surface mineral soil (0–15 cm increased 6 months after thinning with prescribed fire treatments; thinning only resulted in net N immobilization. The rates returned to pre-treatment levels after one year. Based on phospholipid fatty acid composition, microbial communities in treated areas were similar to untreated areas (control in the surface organic horizon and mineral soil (0–5 cm after treatments. Soil potential enzyme activities were not significantly altered by any of the three fuel treatments. Our results suggest that a variety of one-time alternative fuel treatments can reduce fire hazard without degrading soil fertility.

Temperature dependent structural, luminescent and XPS studies of CdO:Ga thin films deposited by spray pyrolysis

International Nuclear Information System (INIS)

Moholkar, A.V.; Agawane, G.L.; Sim, Kyu-Ung; Kwon, Ye-bin; Choi, Doo Sun; Rajpure, K.Y.; Kim, J.H.

2010-01-01

Research highlights: → The CdO:Ga thin films seems an alternative to traditional TCO materials used in photovoltaic applications. This work deals the effect of deposition temperature on sprayed CdO:Ga films with respect to the structural, luminescent and XPS studies. → The crystalline quality of the GCO films improves with deposition temperature. → The oxygen vacancies are responsible for n-type conductivity and green emission. → The minimum resistivity, highest carrier concentration and mobility are 1.9 x 10 -4 Ω cm, 11.7 x 10 21 cm -3 and 27.64 cm 2 V -1 s -1 , respectively. - Abstract: The structural, compositional, photoluminescent and XPS properties of CdO:Ga thin films deposited at temperatures ranging from 275 to 350 o C, using spray pyrolysis are reported. X-ray diffraction characterization of as-deposited GCO thin films reveals that films are of cubic structure with a (2 0 0) preferred orientation. The crystalline quality of the GCO films improves and the grain size increases with deposition temperature. The EDS analyses confirm oxygen deficiency present in the film and are responsible for n-type conductivity. The photoluminescence spectra demonstrated that the green emission peaks of CdO thin films are centered at 482 nm. The relative intensity of these peaks is strongly dependent on the deposition temperature. Oxygen vacancies are dominant luminescent centers for green emission in CdO thin films. The XPS measurement shows the presence of Cd, Ga, O and C elements and confirms that CdO:Ga films are cadmium-rich.

Influence of film thickness on structural, optical, and electrical properties of spray deposited antimony doped SnO{sub 2} thin films

Energy Technology Data Exchange (ETDEWEB)

Yadav, Abhijit A., E-mail: aay_physics@yahoo.co.in

2015-09-30

Transparent conducting antimony doped SnO{sub 2} thin films with varying thickness were deposited by chemical spray pyrolysis technique from non-aqueous solvent Propan-2-ol. The effect of film thickness on the properties of antimony doped SnO{sub 2} thin films have been studied. X-ray diffraction measurements showed tetragonal crystal structure of as-deposited antimony doped SnO{sub 2} films irrespective of film thickness. The surface morphology of antimony doped SnO{sub 2} thin film is spherical with the continuous distribution of grains. Electrical and optical properties were investigated by Hall Effect and optical measurements. The average optical transmittance of films decreased from 89% to 73% within the visible range (350–850 nm) with increase in film thickness. The minimum value of sheet resistance observed is 4.81 Ω/cm{sup 2}. The lowest resistivity found is 3.76 × 10{sup −4} Ω cm at 660 nm film thickness. - Highlights: • Effect of film thickness on the properties of antimony doped SnO{sub 2} thin films • Crystalline size in the range of 34–37 nm • Average transmittance decreased from 89% to 73% in the visible region. • Minimum sheet resistance of 4.81 Ω/cm{sup 2} • Lowest resistivity is found to be 3.76 × 10{sup −4} Ω cm at 660 nm film thickness.

Thin films of copper antimony sulfide: A photovoltaic absorber material

Energy Technology Data Exchange (ETDEWEB)

Ornelas-Acosta, R.E. [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, San Nicolás de los Garza, Nuevo León 66450 (Mexico); Shaji, S. [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, San Nicolás de los Garza, Nuevo León 66450 (Mexico); Universidad Autónoma de Nuevo León-CIIDIT, Apodaca, Nuevo León (Mexico); Avellaneda, D.; Castillo, G.A.; Das Roy, T.K. [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, San Nicolás de los Garza, Nuevo León 66450 (Mexico); Krishnan, B., E-mail: kbindu_k@yahoo.com [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, San Nicolás de los Garza, Nuevo León 66450 (Mexico); Universidad Autónoma de Nuevo León-CIIDIT, Apodaca, Nuevo León (Mexico)

2015-01-15

Highlights: • CuSbS{sub 2} thin films were prepared by heating Sb{sub 2}S{sub 3}/Cu layers. • Analyzed the structure, composition, optical, and electrical properties. • PV structures: glass/SnO{sub 2}:F/n-CdS/p-CuSbS{sub 2}/C/Ag were formed at different conditions. • The PV parameters (J{sub sc}, V{sub oc}, and FF) were evaluated from the J–V characteristics. • J{sub sc}: 0.52–3.20 mA/cm{sup 2}, V{sub oc}:187–323 mV, FF: 0.27–0.48 were obtained. - Abstract: In this work, we report preparation and characterization of CuSbS{sub 2} thin films by heating glass/Sb{sub 2}S{sub 3}/Cu layers and their use as absorber material in photovoltaic structures: glass/SnO{sub 2}:F/n-CdS/p-CuSbS{sub 2}/C/Ag. The Sb{sub 2}S{sub 3} thin films of 600 nm were prepared by chemical bath deposition on which copper thin films of 50 nm were thermally evaporated, and the glass/Sb{sub 2}S{sub 3}/Cu multilayers were heated in vacuum at different temperatures. X-ray diffraction analysis showed the formation of orthorhombic CuSbS{sub 2} after heating the precursor layers. Studies on identification and chemical state of the elements were done using X-ray photoelectron spectroscopy. The optical band gap of the CuSbS{sub 2} thin films was 1.55 eV and the thin films were photoconductive. The photovoltaic parameters of the devices using CuSbS{sub 2} as absorber and CdS as window layer were evaluated from the J–V curves, yielding J{sub sc}, V{sub oc}, and FF values in the range of 0.52–3.20 mA/cm{sup 2}, 187–323 mV, and 0.27–0.48, respectively, under illumination of AM1.5 radiation.

Growth of large-size-two-dimensional crystalline pentacene grains for high performance organic thin film transistors

Directory of Open Access Journals (Sweden)

Chuan Du

2012-06-01

Full Text Available New approach is presented for growth of pentacene crystalline thin film with large grain size. Modification of dielectric surfaces using a monolayer of small molecule results in the formation of pentacene thin films with well ordered large crystalline domain structures. This suggests that pentacene molecules may have significantly large diffusion constant on the modified surface. An average hole mobility about 1.52 cm2/Vs of pentacene based organic thin film transistors (OTFTs is achieved with good reproducibility.

Layered Cu-based electrode for high-dielectric constant oxide thin film-based devices

International Nuclear Information System (INIS)

Fan, W.; Saha, S.; Carlisle, J.A.; Auciello, O.; Chang, R.P.H.; Ramesh, R.

2003-01-01

Ti-Al/Cu/Ta multilayered electrodes were fabricated on SiO 2 /Si substrates by ion beam sputtering deposition, to overcome the problems of Cu diffusion and oxidation encountered during the high dielectric constant (κ) materials integration. The Cu and Ta layers remained intact through the annealing in oxygen environment up to 600 deg. C. The thin oxide layer, formed on the Ti-Al surface, effectively prevented the oxygen penetration toward underneath layers. Complex oxide (Ba x Sr 1-x )TiO 3 (BST) thin films were grown on the layered Ti-Al/Cu/Ta electrodes using rf magnetron sputtering. The deposited BST films exhibited relatively high permittivity (150), low dielectric loss (0.007) at zero bias, and low leakage current -8 A/cm 2 at 100 kV/cm

Enhanced photoelectrochemical properties of 100 MeV Si8+ ion irradiated barium titanate thin films

International Nuclear Information System (INIS)

Solanki, Anjana; Choudhary, Surbhi; Satsangi, Vibha R.; Shrivastav, Rohit; Dass, Sahab

2013-01-01

Highlights: ► Effect of 100 MeV Si 8+ ion irradiation on photoelectrochemical (PEC) properties of BaTiO 3 thin films was studied. ► Films were deposited on Indium doped Tin Oxide (ITO) coated glass by sol–gel spin coating technique. ► Optimal irradiation fluence for best PEC response was 5 × 10 11 ion cm −2 . ► Maximum photocurrent density was observed to be 0.7 mA cm −2 at 0.4 V/SCE. ► Enhanced photo-conversion efficiency was due to maximum negative flatband potential, donor density and lowest resistivity. -- Abstract: Effects of high electronic energy deposition on the structure, surface topography, optical property and photoelectrochemical behavior of barium titanate (BaTiO 3 ) thin films were investigated by irradiating films with 100 MeV Si 8+ ions at different ion fluences in the range of 1 × 10 11 –2 × 10 13 ions cm −2 . BaTiO 3 thin films were deposited on indium tin oxide coated glass substrate by sol gel spin coating method. Irradiation induced modifications in the films were analyzed using the results from XRD, SEM, cross sectional SEM, AFM and UV–Vis spectrometry. Maximum photocurrent density of 0.7 mA cm −2 at 0.4 V/SCE and applied bias hydrogen conversion efficiency (ABPE) of 0.73% was observed for BaTiO 3 film irradiated at 5 × 10 11 ions cm −2 , which can be attributed to maximum negative value of the flatband potential and donor density and lowest resistivity

ZnO Thin Film Electronics for More than Displays

Science.gov (United States)

Ramirez, Jose Israel

Zinc oxide thin film transistors (TFTs) are investigated in this work for large-area electronic applications outside of display technology. A constant pressure, constant flow, showerhead, plasma-enhanced atomic layer deposition (PEALD) process has been developed to fabricate high mobility TFTs and circuits on rigid and flexible substrates at 200 °C. ZnO films and resulting devices prepared by PEALD and pulsed laser deposition (PLD) have been compared. Both PEALD and PLD ZnO films result in densely packed, polycrystalline ZnO thin films that were used to make high performance devices. PEALD ZnO TFTs deposited at 300 °C have a field-effect mobility of ˜ 40 cm2/V-s (and > 20 cm2/V-S deposited at 200 °C). PLD ZnO TFTs, annealed at 400 °C, have a field-effect mobility of > 60 cm2/V-s (and up to 100 cm2/V-s). Devices, prepared by either technique, show high gamma-ray radiation tolerance of up to 100 Mrad(SiO2) with only a small radiation-induced threshold voltage shift (VT ˜ -1.5 V). Electrical biasing during irradiation showed no enhanced radiation-induced effects. The study of the radiation effects as a function of material stack thicknesses revealed the majority of the radiation-induced charge collection happens at the semiconductor-passivation interface. A simple sheet-charge model at that interface can describe the radiation-induced charge in ZnO TFTs. By taking advantage of the substrate-agnostic process provided by PEALD, due to its low-temperature and excellent conformal coatings, ZnO electronics were monolithically integrated with thin-film complex oxides. Application-based examples where ZnO electronics provide added functionality to complex oxide-based devices are presented. In particular, the integration of arrayed lead zirconate titanate (Pb(Zr, Ti)O3 or PZT) thin films with ZnO electronics for microelectromechanical systems (MEMs) and deformable mirrors is demonstrated. ZnO switches can provide voltage to PZT capacitors with fast charging and slow

Effect of deposition temperature on the properties of ZnO-doped indium oxide thin films

Energy Technology Data Exchange (ETDEWEB)

Lee, Seung Jin; Cho, Shin Ho [Silla University, Busan (Korea, Republic of)

2014-05-15

ZnO-doped In{sub 2}O{sub 3} (ZIO) thin films were deposited on quartz substrates at various deposition temperatures by radio-frequency magnetron sputtering. All the ZIO thin films showed a significant dependence on the deposition temperature. A strong preferential growth orientation was observed for all samples except the one deposited at 25 .deg. C. As the deposition temperature was increased, the crystalline orientation of the main (222) plane did not change, but the full width at half maximum got smaller and the intensity increased rapidly. The ZIO thin film deposited at 100 .deg. C showed the highest figure of merit with an average particle size of 60 nm, a bandgap energy of 3.51 eV, an electrical resistivity of 2.63 x 10{sup -3} Ωcm, and an electron concentration of 4.99 x 10{sup 20} cm{sup -3}. A blue-shift of optical bandgap energy was observed with increasing deposition temperature. These results suggest that the optimum deposition temperature for growing high-quality ZIO films is 100 .deg. C and that the structural, optical, and electrical properties of ZIO thin films can be modulated by controlling the deposition temperature.

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.

Changes in optical properties of polystyrene thin films by proton beam irradiation

Energy Technology Data Exchange (ETDEWEB)

Hwang, Sung Hyun; Jung, Jin Mook; Choi, Jae Hak [Dept. of of Polymer Science and Engineering, Chungnam National University, Daejeon (Korea, Republic of); Jung, Chan Hee; Hwang, In Tae; Shin, Jun Hwa [Research Division for Industry and Environment, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup(Korea, Republic of)

2017-06-15

In this study, changes in optical properties of polystyrene (PS) thin films by proton irradiation were investigated. PS thin films were irradiated with 150 keV proton ions at fluences ranging from 1 × 10{sup 15} to 1 × 10{sup 16} ions cm{sup -2}. The chemical structures and optical properties of proton beam-irradiated PS thin films were investigated by using a FT-IR spectrometer, an UVvis spectrophotometer, a photoluminescence (PL) and a fluorescence microscope. The results of the chemical structure analysis revealed that chemical functional groups, such as OH, C=O, and C=C, were formed in the PS films due to the oxidation and formation of carbon clusters by proton beam irradiation. The PL emission was generated and gradually red-shifted with an increasing fluence due to the higher formation of sp2 carbon clusters by proton beam irradiation. The highest PL intensity was obtained at a fluence of 5×10{sup 15} ions cm{sup -2}. The optical band gap of PS calculated by using a Tauc’s plot decreased with increasing the fluence due to the formation of sp2 carbon clusters by proton beam irradiation.

Structures and electronic properties of thin-films of polycyclic aromatic hydrocarbons

International Nuclear Information System (INIS)

Natsume, Yutaka; Minakata, Takashi; Aoyagi, Takeshi

2009-01-01

We report the fabrication and characterization of organic thin-film transistors (TFTs) using several polycyclic aromatic hydrocarbons (PAHs). Pentacene, ovalene, dibenzocoronene and hexabenzocoronene were deposited as organic semiconductors on silicon wafers with gold electrodes as the bottom-contact configuration of the TFTs. The pentacene TFT showed the highest field-effect mobility of more than 0.1 cm 2 /Vs in comparison with the other PAHs. The results clarified that the high field-effect mobility of the pentacene thin film is due to large grain size and intrinsic electronic properties

Calculation for laser-produced plasmas conditions of thin middle-Z targets: Pt.I

International Nuclear Information System (INIS)

Peng Huimin; Zhang Guoping; Sheng Jiatian; Shao Yunfeng; Zhang Yinchun

1988-01-01

An one-dimentional non-LTE laser irradiated code was used to simulate the laser-produced plasmas conditions of thin middle Z targets with high intensities (about 10 13 W/cm 2 ) irradiation. Following physical processes are considered: bremsstrahlung, radiative ionization, collisional ionization by electrons and their inverse processes, Compton scattering. Fokker-Planck approximtaion is used in Compton scattering; the thermal flux limits are taken for electrons and ions in the calculating, and the multigroup flux-limited diffusion approximation is taken for the radiative transport equations. The average-atom model is used to calculate the population probabilities of atoms. Laser absorption via inverse bremsstrahlung is considered to be the most important in the simulation. Using laser beams with intensities 5 x 10 13 W/cm 2 and 1 x 10 14 W/cm 2 , λ L = 0.53 μm, τ = 450 ps to irradiate thin Se target from single-side and double-sides separately, the computational results for laser-produced plasmas conditions are well agree with experimental results

Cu2SixSn1-xS3 Thin Films Prepared by Reactive Magnetron Sputtering For Low-Cost Thin Film Solar Cells

Science.gov (United States)

Yan, Chang; Liu, Fang-Yang; Lai, Yan-Qing; Li, Jie; Liu, Ye-Xiang

2011-10-01

We report the preparation of Cu2SixSn1-xS3 thin films for thin film solar cell absorbers using the reactive magnetron co-sputtering technique. Energy dispersive spectrometer and x-ray diffraction analyses indicate that Cu2Si1-xSnxS3 thin films can be synthesized successfully by partly substituting Si atoms for Sn atoms in the Cu2SnS3 lattice, leading to a shrinkage of the lattice, and, accordingly, by 2θ shifting to larger values. The blue shift of the Raman peak further confirms the formation of Cu2SixSn1-xS3. Environmental scanning electron microscope analyses reveal a polycrystalline and homogeneous morphology with a grain size of about 200-300 nm. Optical measurements indicate an optical absorption coefficient of higher than 104 cm-1 and an optical bandgap of 1.17±0.01 eV.

Thin film microelectrodes for electrochemical detection of neurotransmitters

DEFF Research Database (Denmark)

Larsen, Simon Tylsgaard

An important signaling process in the nervous system is the release of chemical messengers called neurotransmitters from neurons. In this thesis alternative thin film electrode materials for applications targeting electrochemical detection of neurotransmitters in chip devices were evaluated...... and conductive polymer microelectrodes made of Pedot:Pss were also fabricated and used successfully to measure transmitter release from cells. The use of different thin film electrodes for low-noise amperometric measurements of single events of transmitter release from neuronal cells was studied....... For this application a very low current noise is needed together with a large temporal resolution. It was shown, that resistive and capacitive properties of thin film electrode materials are determining their usefulness in low-noise amperometric measurements. An analytical expression for the noise was derived...

Improving the optical and crystalline properties on CdS thin films growth on small and large area by using CBD technique

Energy Technology Data Exchange (ETDEWEB)

Albor A, M. L.; Flores M, J. M.; Hernandez V, C.; Contreras P, G.; Mejia G, C.; Rueda M, G. [IPN, Escuela Superior de Fisica y Matematicas, Departamento de Fisica, Unidad Profesional Adolfo Lopez Mateos, Zacatenco, 07738 Ciudad de Mexico (Mexico); Gonzalez T, M. A. [IPN, Escuela Superior de Computo, Departamento de Formacion Basica, Unidad Profesional Adolfo Lopez Mateos, 07738 Ciudad de Mexico (Mexico)

2016-11-01

CdS polycrystalline thin films have been used as window layer in solar cells; the optical and crystalline quality of the CdS-partner plays and important role in the photovoltaic device performance. CdS thin films were deposited by using Chemical Bath Deposition. The SnO{sub 2}:F substrates used were chemically treated with HCl (0.1 M) and others were thermally annealed in different atmospheres (Ar and O{sub 2}). The physical properties of CdS thin films were influenced by the HCl treatment, position, size and the substrates movement inside the reaction beaker. The CdS samples were deposited in areas of 4 cm{sup 2}, 50 cm{sup 2} and 100 cm{sup 2}. Finally CdS thin films with thickness of 35-300 nm with good optical and crystalline quality on a uniform morphology were obtained. Transmittance values were obtained for all samples about 85-90 % with an average of gap energy of 2.5 eV. The structural characteristics of the samples were determined by the X-ray diffraction patterns, by means of a D-500 Siemens X-ray system. (Author)

Preparation of thin vyns films

International Nuclear Information System (INIS)

Blanc, R.; Chedin, P.; Gizon, A.

1965-01-01

The fabrication of thin films of VYNS resin (copolymer of chloride and vinyl acetate) of superficial density from 3 to 50 μg/cm 2 with solutions in cyclohexanone is presented. Study and discussion of some properties compared with formvar film (polyvinyl formals). It appears that both can be used as source supports but formvar films are prepared more easily and more quickly, in addition they withstand higher temperatures. The main quality of VYNS is that they can be easily separated even several days after their preparation [fr

Electrical and optical properties of nitrogen doped SnO2 thin films deposited on flexible substrates by magnetron sputtering

International Nuclear Information System (INIS)

Fang, Feng; Zhang, Yeyu; Wu, Xiaoqin; Shao, Qiyue; Xie, Zonghan

2015-01-01

Graphical abstract: The best SnO 2 :N TCO film: about 80% transmittance and 9.1 × 10 −4 Ω cm. - Highlights: • Nitrogen-doped tin oxide film was deposited on PET by RF-magnetron sputtering. • Effects of oxygen partial pressure on the properties of thin films were investigated. • For SnO 2 :N film, visible light transmittance was 80% and electrical resistivity was 9.1 × 10 −4 Ω cm. - Abstract: Nitrogen-doped tin oxide (SnO 2 :N) thin films were deposited on flexible polyethylene terephthalate (PET) substrates at room temperature by RF-magnetron sputtering. Effects of oxygen partial pressure (0–4%) on electrical and optical properties of thin films were investigated. Experimental results showed that SnO 2 :N films were amorphous state, and O/Sn ratios of SnO 2 :N films were deviated from the standard stoichiometry 2:1. Optical band gap of SnO 2 :N films increased from approximately 3.10 eV to 3.42 eV as oxygen partial pressure increased from 0% to 4%. For SnO 2 :N thin films deposited on PET, transmittance was about 80% in the visible light region. The best transparent conductive oxide (TCO) deposited on flexible PET substrates was SnO 2 :N thin films preparing at 2% oxygen partial pressure, the transmittance was about 80% and electrical conductivity was about 9.1 × 10 −4 Ω cm

Hall effect of K-doped superconducting thin films

Energy Technology Data Exchange (ETDEWEB)

Son, Eunseon; Lee, Nam Hoon; Kang, Won Nam [Dept. of physics, Sungkyunkwan University, Suwon (Korea, Republic of); Hwang, Tae Jong; Kim, Dong Ho [Dept. of physics, Yeungnam University, Gyeongsan(Korea, Republic of)

2013-09-15

We have studied Hall effect for potassium (K)-doped BaFe{sub 2}As{sub 2}superconducting thin films by analyzing the relation between the longitudinal resistivity (ρ{sub xy}) and the Hall resistivity (ρ{sub xy}). The thin films used in this study were fabricated on Al{sub O3} (000l) substrates by using an ex-situ pulsed laser deposition (PLD) technique under a high-vacuum condition of ∼10{sup -6} Torr. The samples showed the high superconducting transition temperatures (T{sub C}) of ∼40 K. The ρ{sub xx} and ρ{sub xy}the for K-doped BaFeAs{sub 2} thin films were measured by using a physical property measurement system (PPMS) with a temperature sweep (T-sweep) mode at an applied current density of 100 A/cm{sup 2} and at magnetic fields from 0 up to 9 T. We report the T-sweep results of the ρ{sub xx} and the ρ{sub xy} to investigate Hall scaling behavior on the basis of the relation of ρ{sub xy} = A(ρ{sub xy}){sup β}. The ρ{sub xx} values are 3.0 ± 0.2 in the c-axis-oriented K-doped BaFeAs{sub 2} thin films, whereas the thin films with various oriented-directions like a polycrystal showed slightly lower β than that of c-axis-oriented thin films. Interestingly, the β value is decreased with increasing magnetic fields.

Fabrication of thermally evaporated Al thin film on cylindrical PET monofilament for wearable computing devices

Science.gov (United States)

Liu, Yang; Kim, Eunju; Han, Jeong In

2016-01-01

During the initial development of wearable computing devices, the conductive fibers of Al thin film on cylindrical PET monofilament were fabricated by thermal evaporation. Their electrical current-voltage characteristics curves were excellent for incorporation into wearable devices such as fiber-based cylindrical capacitors or thin film transistors. Their surfaces were modified by UV exposure and dip coating of acryl or PVP to investigate the surface effect. The conductive fiber with PVP coating showed the best conductivities because the rough surface of the PET substrate transformed into a smooth surface. The conductivities of PET fiber with and without PVP were 6.81 × 103 Ω-1cm-1 and 5.62 × 103 Ω-1cm-1, respectively. In order to understand the deposition process of Al thin film on cylindrical PET, Al thin film on PET fiber was studied using SEM (Scanning Electron Microscope), conductivities and thickness measurements. Hillocks on the surface of conductive PET fibers were observed and investigated by AFM on the surface. Hillocks were formed and grown during Al thermal evaporation because of severe compressive strain and plastic deformation induced by large differences in thermal expansion between PET substrate and Al thin film. From the analysis of hillock size distribution, it turns out that hillocks grew not transversely but longitudinally. [Figure not available: see fulltext.

Liquid crystals for organic thin-film transistors

Science.gov (United States)

Iino, Hiroaki; Usui, Takayuki; Hanna, Jun-Ichi

2015-04-01

Crystalline thin films of organic semiconductors are a good candidate for field effect transistor (FET) materials in printed electronics. However, there are currently two main problems, which are associated with inhomogeneity and poor thermal durability of these films. Here we report that liquid crystalline materials exhibiting a highly ordered liquid crystal phase of smectic E (SmE) can solve both these problems. We design a SmE liquid crystalline material, 2-decyl-7-phenyl-[1]benzothieno[3,2-b][1]benzothiophene (Ph-BTBT-10), for FETs and synthesize it. This material provides uniform and molecularly flat polycrystalline thin films reproducibly when SmE precursor thin films are crystallized, and also exhibits high durability of films up to 200 °C. In addition, the mobility of FETs is dramatically enhanced by about one order of magnitude (over 10 cm2 V-1 s-1) after thermal annealing at 120 °C in bottom-gate-bottom-contact FETs. We anticipate the use of SmE liquid crystals in solution-processed FETs may help overcome upcoming difficulties with novel technologies for printed electronics.

Structural and optical studies of 100 MeV Au irradiated thin films of tin oxide

Science.gov (United States)

Jaiswal, Manoj Kumar; Kanjilal, D.; Kumar, Rajesh

2013-11-01

Thin films of tin(IV) oxide (SnO2) of 100 nm thickness were grown on silicon (1 0 0) matrices by electron beam evaporation deposition technique under high vacuum. The thicknesses of these films were monitored by piezo-sensor attached to the deposition chamber. Nanocrystallinity is achieved in these thin films by 100 MeV Au8+ using 1 pnA current at normal incidence with ion fluences varying from 1 × 1011 ions/cm2 to 5 × 1013 ions/cm2. Swift Heavy Ion beam irradiation was carried out by using 15 UD Pelletron Accelerator at IUAC, New Delhi, India. Optical studies of pristine and ion irradiated thin films were characterized by UV-Visible spectroscopy and Fourier Transform Infrared (FTIR) spectroscopy. Prominent peak at 610 cm-1 in FTIR spectrum confirmed the O-Sn-O bonding of tin(IV) oxide. For Surface topographical studies and grain size calculations, these films were characterized by Atomic Force Microscope (AFM) using Nanoscope III-A. Crystallinity and phase transformation due to irradiation of pristine and irradiated films were characterized by Glancing Angle X-ray Diffraction (GAXRD) using Brucker-D8 advance model. GAXRD results show improvement in crystallinity and phase transformation due to swift heavy ion irradiation. Grain size distribution was verified by AFM and GAXRD results. Swift heavy ion induced modifications in thin films of SnO2 were confirmed by the presence of prominent peaks at 2θ values of 30.65°, 32.045°, 43.94°, 44.96° and 52.36° in GAXRD spectrum.

Effect of Ag doping on opto-electrical properties of CdS thin films for solar cell applications

International Nuclear Information System (INIS)

Nazir, Adnan; Toma, Andrea; Shah, Nazar Abbas; Panaro, Simone; Butt, Sajid; Sagar, Rizwan ur Rehman; Raja, Waseem; Rasool, Kamran; Maqsood, Asghari

2014-01-01

Highlights: • Polycrystalline CdS thin films are fabricated by means of Close Spaced Sublimation technique. • Ag is doped by simple ion-exchange technique in order to reduce resistivity of CdS thin films. • Remarkable reduction in resistivity without introducing many transparency losses. - Abstract: Cadmium sulfide (CdS) polycrystalline thin films of different thicknesses (ranging from 370 nm to 750 nm) were fabricated on corning glass substrates using Close Spaced Sublimation (CSS) technique. Optical and electrical investigation revealed that CdS thin films show an appreciable transparency (50–70% transmission) in visible range and a highly resistive behavior (10 6 Ω cm). Samples were doped by silver (Ag) at different concentrations, using ion exchange technique, in order to reduce the resistivity of CdS thin films and to improve their efficiency as a window layer for solar cell application. The doping of Ag in pure CdS thin films resulted into an increase of surface roughness and a decrease both in electrical resistivity and in transparency. By optimizing annealing parameters, we were able to properly control the optical properties of the present system. In fact, the Ag doping of pure CdS films has led to a decrease of the sample resistivity by three orders of magnitude (10 3 Ω cm) against a 20% cut in optical transmission

TI--CR--AL--O thin film resistors

Science.gov (United States)

Jankowski, Alan F.; Schmid, Anthony P.

2000-01-01

Thin films of Ti--Cr--Al--O are used as a resistor material. The films are rf sputter deposited from ceramic targets using a reactive working gas mixture of Ar and O.sub.2. Resistivity values from 10.sup.4 to 10.sup.10 Ohm-cm have been measured for Ti--Cr--Al--O film Ti--Cr--Al--O as a thin film resistor has been found to be thermodynamically stable, unlike other metal-oxide films. The Ti--Cr--Al--O film can be used as a vertical or lateral resistor, for example, as a layer beneath a field emission cathode in a flat panel display; or used to control surface emissivity, for example, as a coating on an insulating material such as vertical wall supports in flat panel displays.

Fabrication of Hydrogenated Amorphous Germanium Thin Layer Film and ItsCharacterization

International Nuclear Information System (INIS)

Agus-Santoso; Lely-Susita RM; Tjipto-Sujitno

2000-01-01

Fabrication of hydrogenated amorphous Germanium thin film by vacuumevaporation method and then deposition with hydrogen atom by glow dischargeplasma radio frequency has been done. This germanium amorphous (a-Ge) thinfilm involves a lot of dangling bonds in the network due to the irregularityof the atomic structures and it will decrease is conductivity. To improve theband properties of (a-Ge) thin film layer a hydrogenated plasma isintroduced. Process of introducing of the hydrogen into the a-Ge film is meanto reduce the dangling bonds so that the best electric conductivity of a Ge:Hthin film will obtained. To identify the hydrogen atom in the sample acharacterization using infrared spectrometer has been done, as well as themeasurement of conductivity of the samples. From the characterization usinginfrared spectroscopy the existence of hydrogen atom was found at absorptionpeak with wave number 1637.5 cm -1 , while the optimum conductivity of thesample 1634.86 Ω -1 cm -1 was achieved at 343 o K. (author)

CuInSe2-Based Thin-Film Photovoltaic Technology in the Gigawatt Production Era

Science.gov (United States)

Kushiya, Katsumi

2012-10-01

The objective of this paper is to review current status and future prospect on CuInSe2 (CIS)-based thin-film photovoltaic (PV) technology. In CIS-based thin-film PV technology, total-area cell efficiency in a small-area (i.e., smaller than 1 cm2) solar cell with top grids has been over 20%, while aperture-area efficiency in a large-area (i.e., larger than 800 cm2 as definition) monolithic module is approaching to an 18% milestone. However, most of the companies with CIS-based thin-film PV technology still stay at a production research stage, except Solar Frontier K.K. In July, 2011, Solar Frontier has joined the gigawatt (GW) group by starting up their third facility with a 0.9-GW/year production capacity. They are keeping the closest position to pass a 16% module-efficiency border by transferring the developed technologies in the R&D and accelerating the preparation for the future based on the concept of a product life-cycle management.

Perovskite Thin Films via Atomic Layer Deposition

KAUST Repository

Sutherland, Brandon R.; Hoogland, Sjoerd; Adachi, Michael M.; Kanjanaboos, Pongsakorn; Wong, Chris T. O.; McDowell, Jeffrey J.; Xu, Jixian; Voznyy, Oleksandr; Ning, Zhijun; Houtepen, Arjan J.; Sargent, Edward H.

2014-01-01

© 2014 Wiley-VCH Verlag GmbH & Co. KGaA. (Graph Presented) A new method to deposit perovskite thin films that benefit from the thickness control and conformality of atomic layer deposition (ALD) is detailed. A seed layer of ALD PbS is place-exchanged with PbI2 and subsequently CH3NH3PbI3 perovskite. These films show promising optical properties, with gain coefficients of 3200 ± 830 cm-1.

Perovskite Thin Films via Atomic Layer Deposition

KAUST Repository

Sutherland, Brandon R.

2014-10-30

© 2014 Wiley-VCH Verlag GmbH & Co. KGaA. (Graph Presented) A new method to deposit perovskite thin films that benefit from the thickness control and conformality of atomic layer deposition (ALD) is detailed. A seed layer of ALD PbS is place-exchanged with PbI2 and subsequently CH3NH3PbI3 perovskite. These films show promising optical properties, with gain coefficients of 3200 ± 830 cm-1.

Exfoliated thin Bi{sub 2}MoO{sub 6} nanosheets supported on WO{sub 3} electrode for enhanced photoelectrochemical water splitting

Energy Technology Data Exchange (ETDEWEB)

Ma, Ying; Jia, Yulong; Wang, Lina [State Key Laboratory for Oxo Synthesis & Selective Oxidation, and National Engineering Research Center for Fine Petrochemical Intermediates, Lanzhou Institute of Chemical Physics, CAS, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Yang, Min [State Key Laboratory for Oxo Synthesis & Selective Oxidation, and National Engineering Research Center for Fine Petrochemical Intermediates, Lanzhou Institute of Chemical Physics, CAS, Lanzhou 730000 (China); Bi, Yingpu, E-mail: yingpubi@licp.cas.cn [State Key Laboratory for Oxo Synthesis & Selective Oxidation, and National Engineering Research Center for Fine Petrochemical Intermediates, Lanzhou Institute of Chemical Physics, CAS, Lanzhou 730000 (China); Qi, Yanxing, E-mail: qiyx@licp.cas.cn [State Key Laboratory for Oxo Synthesis & Selective Oxidation, and National Engineering Research Center for Fine Petrochemical Intermediates, Lanzhou Institute of Chemical Physics, CAS, Lanzhou 730000 (China)

2016-12-30

Highlights: • Thin Bi{sub 2}MoO{sub 6} nanosheets were prepared by microwave assisted ultrasonic separation. • The thin Bi{sub 2}MoO{sub 6} nanosheets could be more favorable to charge shift and separation. • The WO{sub 3}/thin Bi{sub 2}MoO{sub 6} exhibits superior photoelectric activity than WO{sub 3}/Bi{sub 2}MoO{sub 6} film. • The efficient photoelectric property results from facilitated charge separation. - Abstract: Thin Bi{sub 2}MoO{sub 6} nanosheets are obtained by a microwave-assisted ultrasonic separation process. After exfoliation, the thinner and uniform nanosheets with a thickness of about 10 nm were obtained. The exfoliated nanosheets would provide many amazing functionalities such as high electron mobility and quantum Hall effects. Therefore, thin Bi{sub 2}MoO{sub 6} supported on WO{sub 3} electrode (WO{sub 3}/thin Bi{sub 2}MoO{sub 6}) exhibits facilitated charge separation than pure WO{sub 3} film and the un-exfoliated Bi{sub 2}MoO{sub 6} nanosheets supported on WO{sub 3} electrode (WO{sub 3}/Bi{sub 2}MoO{sub 6}). As a result, WO{sub 3}/thin Bi{sub 2}MoO{sub 6} shows remarkably stable photocurrent density of 2.2 mA/cm{sup 2} at 0.8 V{sub SCE} in 0.1 M Na{sub 2}SO{sub 4} which is higher than that of that of WO{sub 3} (1.1 mA/cm{sup 2}) and WO{sub 3}/Bi{sub 2}MoO{sub 6} (1.5 mA/cm{sup 2}).

Fabrication of TiNb{sub 2}O{sub 7} thin film electrodes for Li-ion micro-batteries by pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Daramalla, V. [Materials Research Centre, Indian Institute of Science, Bengalore 560012 (India); Penki, Tirupathi Rao; Munichandraiah, N. [Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bengalore 560012 (India); Krupanidhi, S.B., E-mail: sbk@mrc.iisc.ernet.in [Materials Research Centre, Indian Institute of Science, Bengalore 560012 (India)

2016-11-15

Graphical abstract: The TiNb{sub 2}O{sub 7} thin film electrodes as anode material in Li-ion rechargeable micro-batteries are successfully demonstrated. The pulsed laser deposited TiNb{sub 2}O{sub 7} thin film electrode delivers high discharge specific capacity of 143 μAh μm{sup −1} cm{sup −2} at 50 μA cm{sup −2} current density, with 92% coulombic efficiency. The thin films are very stable in crystal structure, with good fast reversible reaction at average Li-insertion voltage 1.65 V. - Highlights: • TiNb{sub 2}O{sub 7} thin films fabricated by pulsed laser deposition. • TiNb{sub 2}O{sub 7} as anode thin films demonstrated successfully. • High discharge specific capacity with 92% coulombic efficiency. • Excellent crystal stability and good reversible reaction. - Abstract: Pulsed laser deposited TiNb{sub 2}O{sub 7} thin films are demonstrated as anode materials in rechargeable Li-ion micro-batteries. The monoclinic and chemically pure TiNb{sub 2}O{sub 7} films in different morphologies were successfully deposited at 750 °C. The single phase formation was confirmed by grazing incident X-ray diffraction, micro-Raman spectroscopy, high resolution transmission electron microscopy, field emission scanning electron microscopy and X-ray photoelectron spectroscopy. The oxygen partial pressure during the deposition significantly influenced the properties of TiNb{sub 2}O{sub 7} films. The TiNb{sub 2}O{sub 7} thin films exhibited excellent stability with fast kinetics reversible reaction. The TiNb{sub 2}O{sub 7} films showed initial discharge specific capacity of 176, 143 μAh μm{sup −1} cm{sup −2} at 30, 50 μA cm{sup −2} current densities respectively with 92% coulombic efficiency in a non-aqueous electrolyte consisting of Li{sup +} ions. The high discharge specific capacity of TiNb{sub 2}O{sub 7} thin films may be attributed to nanometer grain size with high roughness which offers high surface area for Li-diffusion during charge and discharge

A comparative study of Co thin film deposited on GaAs (1 0 0) and glass substrates

International Nuclear Information System (INIS)

Sharma, A.; Brajpuriya, R.; Tripathi, S.; Jain, D.; Dubey, R.; Shripathi, T.; Chaudhari, S.M.

2006-01-01

The structural, magnetic and transport properties of Co/GaAs (1 0 0) and Co/glass thin films have been investigated. The structural measurements reveal the crystalline nature of Co thin film grown on GaAs, while microcrystalline nature in case of glass substrate. The film grown on GaAs shows higher coercivity (49.0 G), lower saturation magnetization (3.65 x 10 -4 ) and resistivity (8 μΩ cm) values as compared to that on glass substrate (22 G, 4.77 x 10 -4 and 18 μΩ cm). The grazing incidence X-ray reflectivity and photoemission spectroscopy results show the interaction between Co and GaAs at the interface, while the Co layer grown on glass remains unaffected. These observed results are discussed and interpreted in terms of different growth morphologies and structures of as grown Co thin film on both substrates

Structural and electrical properties of CZTS thin films by electrodeposition

Science.gov (United States)

Rao, M. C.; Basha, Sk. Shahenoor

2018-06-01

CZTS (Cu2ZnSnS4) thin films were coated on ITO glass substrates by single bath electrodeposition technique. The prepared films were subsequently characterized by XRD, SEM, FTIR, UV-visible spectroscopy and Raman studies. The thickness of the thin films was measured by wedge method. X-ray diffraction studies revealed the formation of polycrystalline phase. The morphological surface of the prepared thin films was examined by SEM and AFM and showed the presence of microcrystals on the surface of the samples. The elemental analysis and their compositional ratios present in the samples were confirmed by the energy dispersive X-ray analysis. Functional groups and the position of band structure involved in the materials were confirmed by FTIR. Optical absorption studies were performed on the prepared thin films in the wavelength ranging from 300 to 1000 nm and the energy bandgap values were found to be in the range from 1.39 to 1.60 eV. Raman spectral peak which was observed at 360 cm-1 correspond to kesterite phase, was formed due to the vibration of the molecules. Electrical measurements confirmed the nature of the thin film depending on the charge concentration present in the samples.

Experimental determination of kQ factors for cylindrical ionization chambers in 10 cm × 10 cm and 3 cm × 3 cm photon beams from 4 MV to 25 MV.

Science.gov (United States)

Krauss, A; Kapsch, R P

2014-08-07

For the ionometric determination of absorbed dose to water, Dw, in megavoltage photon beams from a linear accelerator, beam-quality-dependent correction factors, kQ, are used for the ionization chambers. By using a water calorimeter, these factors can be determined experimentally and with substantially lower standard uncertainties compared to calculated values of the kQ, which are published in various dosimetry protocols. In this investigation, kQ for different types of cylindrical ionization chambers (NE 2561, NE 2571, FC 65 G) were determined experimentally in 10 cm × 10 cm photon beams from 4 MV to 25 MV (corresponding beam quality index TPR20,10 from 0.64 to 0.80). The measurements were carried out at the linear accelerator facility of the Physikalisch-Technische Bundesanstalt. It is shown that the kQ factors for a single ionization chamber in 10 cm × 10 cm photon beams can be measured with a relative standard uncertainty of 0.31%. In addition to these measurements in 10 cm × 10 cm fields, kQ factors for the NE 2561 chamber were also determined in smaller 3 cm × 3 cm photon beams between 6 MV and 25 MV. In this case, relative standard uncertainties between 0.35 % and 0.38 % are achieved for the kQ factors. It is found for this ionization chamber, that the ratio of the kQ factors in 3 cm × 3 cm and in 10 cm × 10 cm beams increases with increasing TPR20,10 to reach a value of 1.0095 at TPR20,10 = 0.8 with a relative standard uncertainty of 0.4 %.

Gettering of carbon dioxide by erbium thin films

International Nuclear Information System (INIS)

Mehrhoff, T.K.

1980-01-01

The interaction of carbon dioxide and erbium thin films is characterized for temperatures in the region of 300 to 900 0 C and partial pressure of carbon dioxide near 5 x 10 -7 Torr. Dynamic film pumping speeds were measured against a mercury diffusion pump of known pumping speed and conductance. A quadrupole mass spectrometer was used to monitor the carbon dioxide flow which originated from a calibrated leak in the 10 -6 standard cm 3 /s range. Data reduction was via a dedicated minicomputer with associated printer/plotter. Temperature ramp experiments with thin erbium films indicated a significant reaction above 300 0 C. The reaction was preceded by the desorption of water vapor, hydrogen and nitrogen and/or carbon monoxide from the film surface

The large-area CdTe thin film for CdS/CdTe solar cell prepared by physical vapor deposition in medium pressure

Energy Technology Data Exchange (ETDEWEB)

Luo, Run; Liu, Bo; Yang, Xiaoyan; Bao, Zheng; Li, Bing, E-mail: libing70@126.com; Zhang, Jingquan; Li, Wei; Wu, Lili; Feng, Lianghuan

2016-01-01

Graphical abstract: - Highlights: • The large-area CdTe film has been prepared by PVD under the pressure of 0.9 kPa. • The as-prepared CdTe thin film processes excellent photovoltaic properties. • This technique is suitable for depositing large-area CdTe thin film. • The 14.6% champion efficiency CdS/CdTe cell has been achieved. - Abstract: The Cadmium telluride (CdTe) thin film has been prepared by physical vapor deposition (PVD), the Ar + O{sub 2} pressure is about 0.9 kPa. This method is a newer technique to deposit CdTe thin film in large area, and the size of the film is 30 × 40 cm{sup 2}. This method is much different from the close-spaced sublimation (CSS), as the relevance between the source temperature and the substrate temperature is weak, and the gas phase of CdTe is transferred to the substrate by Ar + O{sub 2} flow. Through this method, the compact and uniform CdTe film (30 × 40 cm{sup 2}) has been achieved, and the performances of the CdTe thin film have been determined by transmission spectrum, SEM and XRD. The film is observed to be compact with a good crystallinity, the CdTe is polycrystalline with a cubic structure and a strongly preferred (1 1 1) orientation. Using the CdTe thin film (3 × 5 cm{sup 2}) which is taken from the deposited large-area film, the 14.6% efficiency CdS/CdTe thin film solar cell has been prepared successfully. The structure of the cell is glass/FTO/CdS/CdTe/graphite slurry/Au, short circuit current density (J{sub sc}) of the cell is 26.9 mA/cm{sup 2}, open circuit voltage (V{sub oc}) is 823 mV, and filling factor (FF) is 66.05%. This technique can be a quite promising method to apply in the industrial production, as it has great prospects in the fabricating of large-area CdTe film.

Determination of Am-241, Cm-242 and Cm-244 in environmental samples

International Nuclear Information System (INIS)

Afsar, M.; Schuettelkopf, H.

1988-01-01

An analytical procedure for the determination of Am and Cm in environmental, liquid and gaseous effluent samples was developed. It is based on extraction chromatography with subsequent anion and cation exchange to remove matrix elements and to purify Am and Cm, which are then electrode posited from an oxalate/HCl medium. The mean value of the chemical yield is about 90%. A detection limit of 7 μBq/g is achieved. The decontamination factors for important α emitters are > 10 4 . Four analyses/week can be performed by one technician. (orig./RB) [de

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.

Sputtered molybdenum thin films and the application in CIGS solar cells

Energy Technology Data Exchange (ETDEWEB)

Zhou, D.; Zhu, H., E-mail: hongbing1982@hotmail.com; Liang, X.; Zhang, C.; Li, Z.; Xu, Y.; Chen, J.; Zhang, L.; Mai, Y., E-mail: yaohuamai@hbu.edu.cn

2016-01-30

Graphical abstract: - Highlights: • Mo thin films are prepared by magnetron sputtering. • The dynamic deposition rate increases with the increasing discharge power. • The surface structure of Mo films varies with discharge power and working pressure. • High efficiency CIGS thin film solar cell of 15.2% has been obtained. - Abstract: Molybdenum (Mo) thin films are prepared by magnetron sputtering with different discharge powers and working pressures for the application in Cu(In, Ga)Se{sub 2} (CIGS) thin film solar cells as back electrodes. Properties of these Mo thin films are systematically investigated. It is found that the dynamic deposition rate increases with the increasing discharge power while decreases with the increasing working pressure. The highest dynamic deposition rate of 15.1 nm m/min is achieved for the Mo thin film deposited at the discharge power of 1200 W and at the working pressure of 0.15 Pa. The achieved lowest resistivity of 3.7 × 10{sup −5} Ω cm is attributed to the large grains in the compact thin film. The discharge power and working pressure have great influence on the sputtered Mo thin films. High efficiency of 12.5% was achieved for the Cu(In, Ga)Se{sub 2} (CIGS) thin film solar cells with Mo electrodes prepared at 1200 W and low working pressures. By further optimizing material and device properties, the conversion efficiency has reached to 15.2%.

Optical properties of titanium trisulphide (TiS3) thin films

International Nuclear Information System (INIS)

Ferrer, I.J.; Ares, J.R.; Clamagirand, J.M.; Barawi, M.; Sánchez, C.

2013-01-01

Titanium trisulphide thin films have been grown on quartz substrates by sulphuration of electron-beam evaporated Ti layers (d ∼ 300 nm) in a vacuum sealed ampoule in the presence of sulphur powder at 550 °C for different periods of time (1 to 20 h). Thin films were characterized by X-ray diffraction, energy dispersive analyses of X-ray and scanning electron microscopy. Results demonstrate that films are composed by monoclinic titanium trisulphide. Films show n-type conductivity with a relatively high resistivity (ρ ∼ 4 ± 2 Ω·cm) and high values of the Seebeck coefficient (− 600 μV/K) at room temperature. Values of the optical absorption coefficient about α ∼ 10 5 cm −1 , determined from reflectance and transmittance measurements, have been obtained at photon energies hυ > 2 eV. The absorption coefficient dependence on the photon energy in the range of 1.6–3.0 eV hints the existence of a direct transition with an energy gap between 1.35 and 1.50 eV. By comparing these results with those obtained from bulk TiS 3 , a direct transition with lower energy is also found which could have been hidden due to the low value of the absorption coefficient in this energy range. - Highlights: ► Thin films of TiS 3 have been obtained by sulphuration of Ti layers. ► Optical properties of TiS 3 thin films have been determined. ► Optical energy gap of TiS 3 has been obtained. ► Optical properties of bulk TiS 3 have been measured and compared with those of films

Utilization of Local Law Enforcement Aerial Resources in Consequence Management (CM) Response

Energy Technology Data Exchange (ETDEWEB)

Wasiolek, Piotr T.; Malchow, Russell L.

2013-03-12

During the past decade the U.S. Department of Homeland Security (DHS) was instrumental in enhancing the nation’s ability to detect and prevent a radiological or nuclear attack in the highest risk cities. Under the DHS Securing the Cities initiative, nearly 13,000 personnel in the New York City region have been trained in preventive radiological and nuclear detection operations, and nearly 8,500 pieces of radiological detection equipment have been funded. As part of the preventive radiological/nuclear detection (PRND) mission, several cities have received funding to purchase commercial aerial radiation detection systems. In 2008, the U.S. Department of Energy, National Nuclear Security Administration Aerial Measuring System (AMS) program started providing Mobile Aerial Radiological Surveillance (MARS) training to such assets, resulting in over 150 HAZMAT teams’ officers and pilots from 10 law enforcement organizations and fire departments being trained in the aerial radiation detection. From the beginning, the MARS training course covered both the PRND and consequence management (CM) missions. Even if the law enforcement main focus is PRND, their aerial assets can be utilized in the collection of initial radiation data for post-event radiological CM response. Based on over 50 years of AMS operational experience and information collected during MARS training, this presentation will focus on the concepts of CM response using aerial assets as well as utilizing law enforcement/fire department aerial assets in CM. Also discussed will be the need for establishing closer relationships between local jurisdictions’ aerial radiation detection capabilities and state and local radiation control program directors, radiological health department managers, etc. During radiological events these individuals may become primary experts/advisers to Incident Commanders for radiological emergency response, especially in the early stages of a response. The knowledge of the existence

ZnS nanostructured thin-films deposited by successive ionic layer adsorption and reaction

Energy Technology Data Exchange (ETDEWEB)

Deshmukh, S. G., E-mail: deshmukhpradyumn@gmail.com; Jariwala, Akshay; Agarwal, Anubha; Patel, Chetna; Kheraj, Vipul, E-mail: vipulkheraj@gmail.com [Department of Applied Physics, Sardar Vallabhbhai National Institute of Technology, Ichchhanath, Surat (India); Panchal, A. K. [Department of Electrical Engineering, Sardar Vallabhbhai National Institute of Technology, Ichchhanath, Surat (India)

2016-04-13

ZnS thin films were grown on glass substrate using successive ionic layer adsorption and reaction (SILAR) technique at room temperature. Aqueous solutions of ZnCl{sub 2} and Na{sub 2}S were used as precursors. The X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Raman spectroscopy and optical absorption measurements were applied to study the structural, surface morphology and optical properties of as-deposited ZnS thin films. The X-ray diffraction profiles revealed that ZnS thin films consist of crystalline grains with cubic phase. Spherical nano grains of random size and well covered on the glass substrate were observed from FESEM. The average grain size were found to be 77 nm, 100 nm and 124 nm for 20 cycles, 40 cycles and 60 cycles samples respectively. For 60 cycle sample, Raman spectra show two prominent peaks at 554 cm{sup −1} and 1094 cm{sup −1}. The optical band gap values were found to be 3.76 eV, 3.72 eV and 3.67 eV for 20 cycle, 40 cycle and 60 cycle samples respectively.

Development of thin pixel detectors on epitaxial silicon for HEP experiments

International Nuclear Information System (INIS)

Boscardin, Maurizio; Calvo, Daniela; Giacomini, Gabriele; Wheadon, Richard; Ronchin, Sabina; Zorzi, Nicola

2013-01-01

The foreseen luminosity of the new experiments in High Energy Physics will require that the innermost layer of vertex detectors will be able to sustain fluencies up to 10 16 n eq /cm 2 . Moreover, in many experiments there is a demand for the minimization of the material budget of the detectors. Therefore, thin pixel devices fabricated on n-type silicon are a natural choice to fulfill these requirements due to their rad-hard performances and low active volume. We present an R and D activity aimed at developing a new thin hybrid pixel device in the framework of PANDA experiments. The detector of this new device is a p-on-n pixel sensor realized starting from epitaxial silicon wafers and back thinned up to 50–100 μm after process completion. We present the main technological steps and some electrical characterization on the fabricated devices before and after back thinning and after bump bonding to the front-end electronics

Development of thin pixel detectors on epitaxial silicon for HEP experiments

Energy Technology Data Exchange (ETDEWEB)

Boscardin, Maurizio, E-mail: boscardi@fbk.eu [FBK, CMM, Via Sommarive 18, I-38123 Povo, Trento (Italy); Calvo, Daniela [INFN and Dipartimento di Fisica, Università di Torino, Via Pietro Giuria, I-10125 Torino (Italy); Giacomini, Gabriele [FBK, CMM, Via Sommarive 18, I-38123 Povo, Trento (Italy); Wheadon, Richard [INFN and Dipartimento di Fisica, Università di Torino, Via Pietro Giuria, I-10125 Torino (Italy); Ronchin, Sabina; Zorzi, Nicola [FBK, CMM, Via Sommarive 18, I-38123 Povo, Trento (Italy)

2013-08-01

The foreseen luminosity of the new experiments in High Energy Physics will require that the innermost layer of vertex detectors will be able to sustain fluencies up to 10{sup 16} n{sub eq}/cm{sup 2}. Moreover, in many experiments there is a demand for the minimization of the material budget of the detectors. Therefore, thin pixel devices fabricated on n-type silicon are a natural choice to fulfill these requirements due to their rad-hard performances and low active volume. We present an R and D activity aimed at developing a new thin hybrid pixel device in the framework of PANDA experiments. The detector of this new device is a p-on-n pixel sensor realized starting from epitaxial silicon wafers and back thinned up to 50–100 μm after process completion. We present the main technological steps and some electrical characterization on the fabricated devices before and after back thinning and after bump bonding to the front-end electronics.

Material engineering to fabricate rare earth erbium thin films for exploring nuclear energy sources

Science.gov (United States)

Banerjee, A.; Abhilash, S. R.; Umapathy, G. R.; Kabiraj, D.; Ojha, S.; Mandal, S.

2018-04-01

High vacuum evaporation and cold-rolling techniques to fabricate thin films of the rare earth lanthanide-erbium have been discussed in this communication. Cold rolling has been used for the first time to successfully fabricate films of enriched and highly expensive erbium metal with areal density in the range of 0.5-1.0 mg/cm2. The fabricated films were used as target materials in an advanced nuclear physics experiment. The experiment was designed to investigate isomeric states in the heavy nuclei mass region for exploring physics related to nuclear energy sources. The films fabricated using different techniques varied in thickness as well as purity. Methods to fabricate films with thickness of the order of 0.9 mg/cm2 were different than those of 0.4 mg/cm2 areal density. All the thin films were characterized using multiple advanced techniques to accurately ascertain levels of contamination as well as to determine their exact surface density. Detailed fabrication methods as well as characterization techniques have been discussed.

A new lithography of functional plasma polymerized thin films

International Nuclear Information System (INIS)

Kim, Sung-O

2001-01-01

The preparation of the resist for the vacuum lithography was carried out by plasma polymerization. The resist manufactured by plasma polymerization is a monomer produced by MMA (Methyl methacrylate). The functional groups of MMA appeared in the PPMMA (Plasma Polymerized Methyl methacrylate) as well, and this was confirmed through an analysis using FT-IR. The polymerization rate increased as a function of the plasma power and decreased as a function of the system pressure. The sensitivity and contrast of the plasma polymerized thin films were 15 μC/cm2 and 4.3 respectively. The size of the pattern manufactured by Vacuum Lithography using the plasma polymerized thin films was 100 nm

OCCURRENCE OF EXTREME SOLAR PARTICLE EVENTS: ASSESSMENT FROM HISTORICAL PROXY DATA

International Nuclear Information System (INIS)

Usoskin, Ilya G.; Kovaltsov, Gennady A.

2012-01-01

The probability of occurrence of extreme solar particle events (SPEs) with proton fluence (>30 MeV) F 30 ≥ 10 10 cm –2 is evaluated based on data on the cosmogenic isotopes 14 C and 10 Be in terrestrial archives covering centennial-millennial timescales. Four potential candidates with F 30 = (1-1.5) × 10 10 cm –2 and no events with F 30 > 2 × 10 10 cm –2 are identified since 1400 AD in the annually resolved 10 Be data. A strong SPE related to the Carrington flare of 1859 AD is not supported by the data. For the last 11,400 years, 19 SPE candidates with F 30 = (1-3) × 10 10 cm –2 are found and clearly no event with F 30 > 5 × 10 10 cm –2 (50 times the SPE of 1956 February 23) has occurred. These values serve as observational upper limits on the strength of SPEs on the timescale of tens of millennia. Two events, ca. 780 and 1460 AD, appear in different data series making them strong candidates for extreme SPEs. We build a distribution of the occurrence probability of extreme SPEs, providing a new strict observational constraint. Practical limits can be set as F 30 ≈ 1, 2-3, and 5×10 10 cm –2 for occurrence probabilities ≈10 –2 , 10 –3 , and 10 –4 yr –1 , respectively. Because of the uncertainties, our results should be interpreted as a conservative upper limit on the SPE occurrence near Earth. The mean solar energetic particle (SEP) flux is evaluated as ≈40 (cm 2 s) –1 , in agreement with estimates from lunar rocks. On average, extreme SPEs contribute about 10% to the total SEP fluence.

Surface Functionalization of WO3 Thin Films with (3-Aminopropyl)triethoxysilane and Succinic Anhydride

Science.gov (United States)

Ta, Thi Kieu Hanh; Tran, Thi Nhu Hoa; Tran, Quang Minh Nhat; Pham, Duy Phong; Pham, Kim Ngoc; Cao, Thi Thanh; Kim, Yong Soo; Tran, Dai Lam; Ju, Heongkyu; Phan, Bach Thang

2017-06-01

We report effects of oxygen plasma treatment on the surface functionalization of WO3 thin films with (3-aminopropyl)triethoxysilane (APTES) and succinic anhydride (SA). X-ray diffraction and x-ray photoelectron spectroscopy results indicate the existence of the WO3 phase. Fourier transform infrared spectroscopy measurement shows clear bands at 1040 cm-1 (Si-O-Si), 1556 cm-1 (N-H), 1655 cm-1 (C=O), 2937 cm-1 (C-H) and 3298 cm-1 (N-H), confirming the surface functionalization efficiency enhanced by prior treatment of oxygen plasma. It thus follows that the prior oxygen plasma treatment activates hydroxylation with more -OH groups on the WO3 surface, which can pave a highly efficient way to the surface functionalization by APTES and SA.

Piezoelectric actuated micro-resonators based on the growth of diamond on aluminum nitride thin films

International Nuclear Information System (INIS)

Hees, J; Heidrich, N; Pletschen, W; Sah, R E; Wolfer, M; Lebedev, V; Nebel, C E; Ambacher, O; Williams, O A

2013-01-01

Unimorph heterostructures based on piezoelectric aluminum nitride (AlN) and diamond thin films are highly desirable for applications in micro- and nanoelectromechanical systems. In this paper, we present a new approach to combine thin conductive boron-doped as well as insulating nanocrystalline diamond (NCD) with sputtered AlN films without the need for any buffer layers between AlN and NCD or polishing steps. The zeta potentials of differently treated nanodiamond (ND) particles in aqueous colloids are adjusted to the zeta potential of AlN in water. Thereby, the nucleation density for the initial growth of diamond on AlN can be varied from very low (10 8 cm −2 ), in the case of hydrogen-treated ND seeding particles, to very high values of 10 11 cm −2 for oxidized ND particles. Our approach yielding high nucleation densities allows the growth of very thin NCD films on AlN with thicknesses as low as 40 nm for applications such as microelectromechanical beam resonators. Fabricated piezo-actuated micro-resonators exhibit enhanced mechanical properties due to the incorporation of boron-doped NCD films. Highly boron-doped NCD thin films which replace the metal top electrode offer Young’s moduli of more than 1000 GPa. (paper)

Highly transparent and conductive Al-doped ZnO nanoparticulate thin films using direct write processing

International Nuclear Information System (INIS)

Vunnam, S; Ankireddy, K; Kellar, J; Cross, W

2014-01-01

Solution processable Al-doped ZnO (AZO) thin films are attractive candidates for low cost transparent electrodes. We demonstrate here an optimized nanoparticulate ink for the fabrication of AZO thin films using scalable, low-cost direct write processing (ultrasonic spray deposition) in air at atmospheric pressure. The thin films were made via thermal processing of as-deposited films. AZO films deposited using the proposed nanoparticulate ink with further reducing in vacuum and rf plasma of forming gas exhibited optical transparency greater than 95% across the visible spectrum, and electrical resistivity of 0.5 Ω cm and it drops down to 7.0 × 10 −2 Ω cm after illuminating with UV light, which is comparable to commercially available tin doped indium oxide colloidal coatings. Various structural analyses were performed to investigate the influence of ink chemistry, deposition parameters, and annealing temperatures on the structural, optical, and electrical characteristics of the spray deposited AZO thin films. Optical micrographs confirmed the presence of surface defects and cracks using the AZO NPs ink without any additives. After adding N-(2-Aminoethyl)-3-aminopropylmethyldimethoxy silane to the ink, AZO films exhibited an optical transparency which was virtually identical to that of the plain glass substrate. (papers)

Comparison of effective transverse piezoelectric coefficients e31,f of Pb(Zr,Ti)O3 thin films between direct and converse piezoelectric effects

Science.gov (United States)

Tsujiura, Yuichi; Kawabe, Saneyuki; Kurokawa, Fumiya; Hida, Hirotaka; Kanno, Isaku

2015-10-01

We evaluated the effective transverse piezoelectric coefficients (e31,f) of Pb(Zr,Ti)O3 (PZT) thin films from both the direct and converse piezoelectric effects of unimorph cantilevers. (001) preferentially oriented polycrystalline PZT thin films and (001)/(100) epitaxial PZT thin films were deposited on (111)Pt/Ti/Si and (001)Pt/MgO substrates, respectively, by rf-magnetron sputtering, and their piezoelectric responses owing to intrinsic and extrinsic effects were examined. The direct and converse |e31,f| values of the polycrystalline PZT thin films were calculated as 6.4 and 11.5-15.0 C/m2, respectively, whereas those of the epitaxial PZT thin films were calculated as 3.4 and 4.6-4.8 C/m2, respectively. The large |e31,f| of the converse piezoelectric property of the polycrystalline PZT thin films is attributed to extrinsic piezoelectric effects. Furthermore, the polycrystalline PZT thin films show a clear nonlinear piezoelectric contribution, which is the same as the Rayleigh-like behavior reported in bulk PZT. In contrast, the epitaxial PZT thin films on the MgO substrate show a piezoelectric response owing to the intrinsic and linear extrinsic effects, and no nonlinear contribution was observed.

General Top-Down Ion Exchange Process for the Growth of Epitaxial Chalcogenide Thin Films and Devices

KAUST Repository

Xia, Chuan

2016-12-30

We demonstrate a versatile top-down ion exchange process, done at ambient temperature, to form epitaxial chalcogenide films and devices, with nanometer scale thickness control. To demonstrate the versatility of our process we have synthesized (1) epitaxial chalcogenide metallic and semiconducting films and (2) free-standing chalcogenide films and (3) completed in situ formation of atomically sharp heterojunctions by selective ion exchange. Epitaxial NiCo2S4 thin films prepared by our process show 115 times higher mobility than NiCo2S4 pellets (23 vs 0.2 cm(2) V-1 s(-1)) prepared by previous reports. By controlling the ion exchange process time, we made free-standing epitaxial films of NiCo2S4 and transferred them onto different substrates. We also demonstrate in situ formation of atomically sharp, lateral Schottky diodes based on NiCo2O4/NiCo2S4 heterojunction, using a single ion exchange step. Additionally, we show that our approach can be easily extended to other chalcogenide semiconductors. Specifically, we used our process to prepare Cu1.8S thin films with mobility that matches single crystal Cu1.8S (25 cm(2) V-1 s(-1)), which is ca. 28 times higher than the previously reported Cu1.8S thin film mobility (0.58 cm(2) V-1 s(-1)), thus demonstrating the universal nature of our process. This is the first report in which chalcogenide thin films retain the epitaxial nature of the precursor oxide films, an approach that will be useful in many applications.

Third generation biosensing matrix based on Fe-implanted ZnO thin film

Science.gov (United States)

Saha, Shibu; Gupta, Vinay; Sreenivas, K.; Tan, H. H.; Jagadish, C.

2010-09-01

Third generation biosensor based on Fe-implanted ZnO (Fe-ZnO) thin film has been demonstrated. Implantation of Fe in rf-sputtered ZnO thin film introduces redox center along with shallow donor level and thereby enhance its electron transfer property. Glucose oxidase (GOx), chosen as model enzyme, has been immobilized on the surface of the matrix. Cyclic voltammetry and photometric assay show that the prepared bioelectrode, GOx/Fe-ZnO/ITO/Glass is sensitive to the glucose concentration with enhanced response of 0.326 μA mM-1 cm-2 and low Km of 2.76 mM. The results show promising application of Fe-implanted ZnO thin film as an attractive matrix for third generation biosensing.

Third generation biosensing matrix based on Fe-implanted ZnO thin film

International Nuclear Information System (INIS)

Saha, Shibu; Gupta, Vinay; Sreenivas, K.; Tan, H. H.; Jagadish, C.

2010-01-01

Third generation biosensor based on Fe-implanted ZnO (Fe-ZnO) thin film has been demonstrated. Implantation of Fe in rf-sputtered ZnO thin film introduces redox center along with shallow donor level and thereby enhance its electron transfer property. Glucose oxidase (GOx), chosen as model enzyme, has been immobilized on the surface of the matrix. Cyclic voltammetry and photometric assay show that the prepared bioelectrode, GOx/Fe-ZnO/ITO/Glass is sensitive to the glucose concentration with enhanced response of 0.326 μA mM -1 cm -2 and low Km of 2.76 mM. The results show promising application of Fe-implanted ZnO thin film as an attractive matrix for third generation biosensing.

Low operating voltage InGaZnO thin-film transistors based on Al2O3 high-k dielectrics fabricated using pulsed laser deposition

International Nuclear Information System (INIS)

Geng, G. Z.; Liu, G. X.; Zhang, Q.; Shan, F. K.; Lee, W. J.; Shin, B. C.; Cho, C. R.

2014-01-01

Low-voltage-driven amorphous indium-gallium-zinc-oxide (IGZO) thin-film transistors (TFTs) with an Al 2 O 3 dielectric were fabricated on a Si substrate by using pulsed laser deposition. Both Al 2 O 3 and IGZO thin films are amorphous, and the thin films have very smooth surfaces. The Al 2 O 3 gate dielectric exhibits a very low leakage current density of 1.3 x 10 -8 A/cm 2 at 5 V and a high capacitance density of 60.9 nF/cm 2 . The IGZO TFT with a structure of Ni/IGZO/Al 2 O 3 /Si exhibits high performance with a low threshold voltage of 1.18 V, a high field effect mobility of 20.25 cm 2 V -1 s -1 , an ultra small subthreshold swing of 87 mV/decade, and a high on/off current ratio of 3 x 10 7 .

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.

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.

Effect of target power on the physical properties of Ti thin films prepared by DC magnetron sputtering with supported discharge

Directory of Open Access Journals (Sweden)

Kavitha A.

2017-02-01

Full Text Available The present paper describes the effect of target power on the properties of Ti thin films prepared by DC magnetron sputtering with (triode mode and without (diode mode supported discharge. The traditional diode magnetron sputtering with an addition of a hot filament has been used to sustain the discharge at a lower pressure. The effect of target power (60, 80, 100 and 120 W on the physical properties of Ti thin films has been studied in diode and triode modes. XRD studies showed that the Ti thin films prepared at a target power up to 100 W in diode mode were amorphous in nature. The Ti thin films exhibited crystalline structure at much lower target power of 80 W with a preferred orientation along (0 0 2 plane. The grain size of Ti thin films prepared in triode mode increased from 64 nm to 80 nm, whereas in diode mode, the grain size increased from 2 nm to 5 nm. EDAX analysis confirmed that the incorporation of reactive gases was lower in triode mode compared to diode mode. The electrical resistivity of Ti thin films deposited in diode mode was found to be 85 µΩ⋅cm (target power 120 W. The electrical resistivity of Ti thin films in triode mode was found to be deceased to 15.2 µΩ⋅cm (target power 120 W.

Uniaxial and biaxial tensioning effects on thin membrane materials. [large space structures

Science.gov (United States)

Hinson, W. F.; Goslee, J. W.

1980-01-01

Thin laminated membranes are being considered for various surface applications on future large space structural systems. Some of the thin membranes would be stretched across or between structural members with the requirement that the membrane be maintained within specified limits of smoothness which would be dictated by the particular applications such as antenna reflector requirements. The multiaxial tensile force required to maintain the smoothness in the membrane needs to be determined for use in the structure design. Therefore, several types of thicknesses of thin membrane materials have been subjected to varied levels of uniaxial and biaxial tensile loads. During the biaxial tests, deviations of the material surface smoothness were measured by a noncontacting capacitance probe. Basic materials consisted of composites of vacuum deposited aluminum on Mylar and Kapton ranging in thickness from 0.00025 in (0.000635 cm) to 0.002 in (0.00508 cm). Some of the material was reinforced with Kevlar and Nomex scrim. The uniaxial tests determined the material elongation and tensile forces up to ultimate conditions. Biaxial tests indicated that a relatively smooth material surface could be achieved with tensile force of approximately 1 to 15 Newtons per centimeter, depending upon the material thickness and/or reinforcement.

Physical properties of chemically deposited Bi{sub 2}S{sub 3} thin films using two post-deposition treatments

Energy Technology Data Exchange (ETDEWEB)

Moreno-García, H., E-mail: hamog@ier.unam.mx [Instituto de Ciencias Físicas, Laboratorio de espectroscopia, Universidad Nacional Autónoma de México, Apartado Postal 48-3, C.P. 62210 Cuernavaca, Morelos (Mexico); Messina, S. [Universidad Autónoma de Nayarit, Ciudad de la Cultura “Amado Nervo” S/N, C.P. 63155 Tepic, Nayarit (Mexico); Calixto-Rodriguez, M. [Universidad Tecnológica Emiliano Zapata del Estado de Morelos, Av. Universidad Tecnológica No. 1, C.P. 62760 Emiliano Zapata, Morelos (Mexico); Martínez, H. [Instituto de Ciencias Físicas, Laboratorio de espectroscopia, Universidad Nacional Autónoma de México, Apartado Postal 48-3, C.P. 62210 Cuernavaca, Morelos (Mexico)

2014-08-30

Highlights: • The post-deposition treatment by Ar plasma is a viable alternative to enhance the optical, electrical, morphological and structural properties of Bi{sub 2}S{sub 3} semiconductor thin films. • The plasma treatment avoids the loss in thickness of the chemically deposited Bi{sub 2}S{sub 3} thin films. • The E{sub g} values were 1.60 eV for the thermally annealed samples and 1.56 eV for the Ar plasma treated samples. • The highest value obtained for the electrical conductivity was 7.7 × 10{sup −2} (Ω cm){sup −1} in plasma treated samples. - Abstract: As-deposited bismuth sulfide (Bi{sub 2}S{sub 3}) thin films prepared by chemical bath deposition technique were treated with thermal annealed in air atmosphere and argon AC plasma. The as-deposited, thermally annealing and plasma treatment Bi{sub 2}S{sub 3} thin films have been characterized by X-ray diffraction (XRD) analysis, atomic force microscopy analysis (AFM), transmission, specular reflectance and electrical measurements. The structural, morphological, optical and electrical properties of the films are compared. The XRD analysis showed that both post-deposition treatments, transform the thin films from amorphous to a crystalline phase. The atomic force microscopy (AFM) measurement showed a reduction of roughness for the films treated in plasma. The energy band gap value of the as-prepared film was E{sub g} = 1.61 eV, while for the film thermally annealed was E{sub g} = 1.60 eV and E{sub g} = 1.56 eV for film treated with Plasma. The electrical conductivity under illumination of the as-prepared films was 3.6 × 10{sup −5} (Ω cm){sup −1}, whereas the conductivity value for the thermally annealed films was 2.0 × 10{sup −3} (Ω cm){sup −1} and for the plasma treated films the electrical conductivity increases up to 7.7 × 10{sup −2} (Ω cm){sup −1}.

Structural, optical and magnetic properties of Mn doped ZnO thin films prepared by pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Aravind, Arun, E-mail: aruncusat@gmail.com [Nanophotonic and Optoelectronic Devices Laboratory, Department of Physics, Cochin University of Science and Technology, Kochi 682 022, Kerala (India); Jayaraj, M.K., E-mail: mkj@cusat.ac.in [Nanophotonic and Optoelectronic Devices Laboratory, Department of Physics, Cochin University of Science and Technology, Kochi 682 022, Kerala (India); Kumar, Mukesh; Chandra, Ramesh [Nano Science Laboratory, Institute Instrumentation Centre, IIT Roorkee, Roorkee 247 667, Uttarakhand (India)

2012-08-01

Highlights: Black-Right-Pointing-Pointer Defect induced Raman active modes in Mn doped ZnO thin films. Black-Right-Pointing-Pointer Room temperature ferromagnetism. Black-Right-Pointing-Pointer Morphological variations of ZnO thin films with Mn doping. Black-Right-Pointing-Pointer Variation of refractive index of ZnO thin films with Mn doping. - Abstract: Zn{sub 1-x}Mn{sub x}O thin films were grown by pulsed laser deposition. The phase purity and the structure were confirmed by X-ray diffraction studies. The films have a transmittance more than 80% in the visible region. The refractive index of Zn{sub 0.90}Mn{sub 0.10}O films is found to be 1.77 at 550 nm. The presence of non-polar E{sub 2}{sup high} and E{sub 2}{sup low} Raman modes in thin films indicates that 'Mn' doping does not change the wurtzite structure of ZnO. Apart from the normal modes of ZnO the Zn{sub 1-x}Mn{sub x}O ceramic targets show two additional modes at 332 cm{sup -1} (I{sub 1}) and 524 cm{sup -1} (I{sub 2}). The broad Raman peaks (340-600 cm{sup -1}) observed Zn{sub 0.90}Mn{sub 0.10}O thin films can be deconvoluted into five peaks, denoted as P{sub 1}-P{sub 5}. The possible origins of Raman peaks in Zn{sub 1-x}Mn{sub x}O films are the structural disorder and morphological change caused by the Mn dopant. The B{sub 1}{sup low}, {sup 2}B{sub 1}{sup low}, B{sub 1}{sup high} and A{sub 1}{sup LO} modes as well as the surface phonon mode have been observed in heavily Mn-doped ZnO films. Zn{sub 0.98}Mn{sub 0.02}O thin film shows room temperature ferromagnetism. The saturation magnetic moment of the Zn{sub 0.98}Mn{sub 0.02}O thin film is 0.42{mu}{sub B}/Mn atom. The undoped ZnO film prepared under the same condition shows diamagnetic nature. At higher doping concentrations the formation of Mn clusters suppress the room temperature ferromagnetism in Zn{sub 1-x}Mn{sub x}O thin films and shows paramagnetism. XPS confirms the incorporation of Mn{sup 2+} into the ZnO lattice.

Structural and optical studies of 100 MeV Au irradiated thin films of tin oxide

Energy Technology Data Exchange (ETDEWEB)

Jaiswal, Manoj Kumar [University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, New Delhi 110 078 (India); Kanjilal, D. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110 067 (India); Kumar, Rajesh, E-mail: rajeshkumaripu@gmail.com [University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, New Delhi 110 078 (India)

2013-11-01

Thin films of tin(IV) oxide (SnO{sub 2}) of 100 nm thickness were grown on silicon (1 0 0) matrices by electron beam evaporation deposition technique under high vacuum. The thicknesses of these films were monitored by piezo-sensor attached to the deposition chamber. Nanocrystallinity is achieved in these thin films by 100 MeV Au{sup 8+} using 1 pnA current at normal incidence with ion fluences varying from 1 × 10{sup 11} ions/cm{sup 2} to 5 × 10{sup 13} ions/cm{sup 2}. Swift Heavy Ion beam irradiation was carried out by using 15 UD Pelletron Accelerator at IUAC, New Delhi, India. Optical studies of pristine and ion irradiated thin films were characterized by UV–Visible spectroscopy and Fourier Transform Infrared (FTIR) spectroscopy. Prominent peak at 610 cm{sup −1} in FTIR spectrum confirmed the O–Sn–O bonding of tin(IV) oxide. For Surface topographical studies and grain size calculations, these films were characterized by Atomic Force Microscope (AFM) using Nanoscope III-A. Crystallinity and phase transformation due to irradiation of pristine and irradiated films were characterized by Glancing Angle X-ray Diffraction (GAXRD) using Brucker-D8 advance model. GAXRD results show improvement in crystallinity and phase transformation due to swift heavy ion irradiation. Grain size distribution was verified by AFM and GAXRD results. Swift heavy ion induced modifications in thin films of SnO{sub 2} were confirmed by the presence of prominent peaks at 2θ values of 30.65°, 32.045°, 43.94°, 44.96° and 52.36° in GAXRD spectrum.

Snowball Earth: Skating on Thin Ice?

Science.gov (United States)

Roberson, A. L.; Stout, A. M.; Pollard, D.; Kasting, J. F.

2011-12-01

There is evidence of at least two intervals of widespread glaciation during the late Neoproterozoic (600-800 Myr ago), which are commonly referred to as "Snowball Earth" episodes. The global nature of these events is indicated by the fact that glacial deposits are found at low paleolatitudes during this time. Models of a global glacial event have produced a variety of solutions at low latitudes: thick ice, thin ice, slushball, and open ocean . The latter two models are similar, except that the slushball model has its ice-line at higher latitudes. To be viable, a model has to be able to account for the survival of life through the glaciations and also explain the existence of cap carbonates and other glacial debris deposited at low latitudes. The "thick-ice" model is not viable because kilometers of ice prevent the penetration of light necessary for the photosynthetic biota below. The "slushball" model is also not viable as it does not allow the formation of cap carbonates. The "thin-ice" model has been discussed previously and can account for continuation of photosynthetic life and glacial deposits at low paleolatitudes. The recently proposed "open-ocean" or "Jormungand" model also satisfies these requirements. What is it, though, that causes some models to produce thin ice near the equator and others to have open water there? We examine this question using a zonally symmetric energy balance climate model (EBM) with flowing sea glaciers to determine what parameter ranges produce each type of solution.

Tunable Gas Permeability of Polymer-Clay Nano Brick Wall Thin Film Assemblies

Science.gov (United States)

Gamboa, Daniel; Priolo, Morgan; Grunlan, Jaime

2010-03-01

Thin films of anionic natural montmorrilonite (MMT) clay and cationic polyethylenimine (PEI) have been produced by alternately dipping a plastic substrate into dilute aqueous mixtures containing each ingredient. After 40 polymer-clay layers have been deposited, the resulting transparent film exhibits an oxygen transmission rate (OTR) below 0.35 cm^3/m^2 . day when the pH of PEI solution is 10. This low permeability is due to a brick wall nanostructure comprised of completely exfoliated clay bricks in polymeric mortar. This brick wall creates an extremely tortuous path at thicknesses below 250 nm and clay concentration above 80 wt%. A 70-bilayer PEI-MMT assembly has an undetectable OTR (< 0.005 cm^3/m^2 . day), which equates to a permeability below SiOx when multiplied by its film thickness of 231 nm. With optical transparency greater than 86% and the ability to be microwaved, these thin film composites are good candidates for flexible electronics packaging and foil replacement for food.

Sliding thin slab, minimum intensity projection imaging for objective analysis of emphysema

International Nuclear Information System (INIS)

Satoh, Shiro; Ohdama, Shinichi; Shibuya, Hitoshi

2006-01-01

The aim of this study was to determine whether sliding thin slab, minimum intensity projection (STS-MinIP) imaging is more advantageous than thin-section computed tomography (CT) for detecting and assessing emphysema. Objective quantification of emphysema by STS-MinIP and thin-section CT was defined as the percentage of area lower than the threshold in the lung section at the level of the aortic arch, tracheal carina, and 5 cm below the carina. Quantitative analysis in 100 subjects was performed and compared with pulmonary function test results. The ratio of the low attenuation area in the lung measured by STS-MinIP was significantly higher than that found by thin-section CT (P<0.01). The difference between STS-MinIP and thin-section CT was statistically evident even for mild emphysema and increased depending on whether the low attenuation in the lung increased. Moreover, STS-MinIP showed a stronger regression relation with pulmonary function results than did thin-section CT (P<0.01). STS-MinIP can be recommended as a new morphometric method for detecting and assessing the severity of emphysema. (author)

Chemically robust carbon nanotube–PTFE superhydrophobic thin films with enhanced ability of wear resistance

Institute of Scientific and Technical Information of China (English)

Kewei Wang; Pan Xiong; Xiuping Xu; Kan Wang; YanLong Li; Yufeng Zheng

2017-01-01

A chemically robust superhydrophobic nanocomposite thin film with enhanced wear resistance is prepared from a composite comprising polytetrafluoroethylene (PTFE) and carbon nanotubes. The superhydrophobic thin films with hierarchical structure are fabricated by spraying an environmentally friendly aqueous dispersion containing carbon nanotubes and PTFE resin on silicon wafer. Thin films with a contact angle of 154.1° ± 2° and a sliding angle less than 2° remain superhydrophobic after abrading over 500 times under a pressure of 50 g/cm2. The thin film is also extremely stable even under much stress conditions. To further the understanding of the enhancement of wear resistance, we investigated the formation of microsized structure and their effects. The growth of microbumps is caused by attracting solution droplet to the hydrophilic islands on hydrophobic surface.

Photo- and Electrochromic Properties of Activated Reactive Evaporated MoO3 Thin Films Grown on Flexible Substrates

Directory of Open Access Journals (Sweden)

K. Hari Krishna

2008-01-01

Full Text Available The molybdenum trioxide (MoO3 thin films were grown onto ITO-coated flexible Kapton substrates using plasma assisted activated reactive evaporation technique. The film depositions were carried out at constant glow power and oxygen partial pressures of 8 W and 1×10−3 Torr, respectively. The influence of substrate temperature on the microstructural and optical properties was investigated. The MoO3 thin films prepared at a substrate temperature of 523 K were found to be composed of uniformly distributed nanosized grains with an orthorhombic structure of α-MoO3. These nanocrystalline MoO3 thin films exhibited higher optical transmittance of about 80% in the visible region with an evaluated optical band gap of 3.29 eV. With the insertion of 12.5 mC/cm2, the films exhibited an optical modulation of 40% in the visible region with coloration efficiency of 22 cm2/C at the wavelength of 550 nm. The MoO3 films deposited at 523 K demonstrated better photochromic properties and showed highest color center concentration for the irradiation time of 30 minutes at 100 mW/cm2.

Synthesis and characterization of spray deposited CZTS thin films for photo-electrochemical application

Science.gov (United States)

Chavda, Arvind; Patel, Biren; Mukhopadhyay, Priyanka Marathey Indrajit; Ray, Abhijit

2018-05-01

Cu2ZnSnS4 (CZTS) is one of the most promising light absorber materials for photovoltaic and photo-electrochemical applications. We synthesized CZTS thin films on a F:SnO2 and soda lime glass substrates by very simple, cost effective and highly scalable spray pyrolysis technique. The films were post treated by rapid thermal processing route of sulfurization to enhance the stoichiometry and crystallinity of the film. The structural, morphological, optical and electrical properties of RTP sulfurized films were studied. The X-ray diffraction (XRD) pattern revealed the formation of tetragonal CZTS phase, which confirmed by Raman analysis with a major peak at 336 cm-1 without the presence of the principle vibration mode of any other secondary phases, such as Cu2SnS3, CuxS(x=1.8,2) etc. The sulfurized film exhibited increased crystallinity and better stoichiometry. The optical and electrical data reveal the direct optical band gap, bulk carrier concentration and resistivity of 1.5 eV, 2.28×1018 cm-3 and 1.21 Ω/cm2, respectively. Finally the photoactivity of CZTS thin films was tested by forming photoelectrochemical cell in 0.1M Na2S2O3 electrolyte (pH=7.72), showing a cathodic photocurrent of nearly 20 µA/cm2 at 0V RHE.

Observations of new particle formation events in the south-eastern Baltic Sea

Directory of Open Access Journals (Sweden)

Kristina Plauškaitė

2010-03-01

Full Text Available New particle formation and growth were observed at a coastal site (Preila station, Lithuania during 1997 and 2000-2002. The total amountof data analysed covers 291 one-day periods, 45 (15% of which were long-term, new particle formation days. Short-term nucleationevents (from a few minutes to one hour and long-term events (from one to eight hours were identified. The mean particlegrowth rate, condensation sink and condensable vapour source rate during nucleation events were 3.9 nm h-1, 1.45 × 10-3 cm-3 s-1 and 7.5 × 104 cm-3 s-1 respectively.The average formation rate J10 was 0.4 cm-3 s-1. The nucleation events were accompaniedmainly by air masses transported from the north (43% and north-west (19%. Meteorological parameters and trace gas (O3, SO2,NO2 concentrations were also analysed. It was found that nucleation events are related to high levels of solar radiation.

Electrical characterization of InAs thin films

Energy Technology Data Exchange (ETDEWEB)

Botha, L.; Shamba, P.; Botha, J.R. [Department of Physics, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa)

2008-07-01

It is known that parallel conduction as a result of surface and /or interface charge accumulation significantly shields the bulk electrical properties of InAs thin films when characterized using Hall measurements. This parallel conduction in InAs can be modeled by using the two-layer model of Nedoluha and Koch [Zeitschrift fuer Physik 132, 608 (1952)]; where an InAs epilayer is treated as consisting of two conductors connected in parallel viz. a bulk and a surface layer. Here, this two-layer model is used to simulate Hall coefficient and conductivity data of InAs thin films ranging from strongly n-doped (n=10{sup 18} cm{sup -3}) to strongly p-doped (p{proportional_to}10{sup 19} cm{sup -3}) material. Conventional Hall approximations, i.e. those that assume uniform conduction from a single band, are then used to predict the apparent carrier concentration and mobility that will be determined from conventional Hall measurements, with the aim of illustrating the error of such a simplified analysis of InAs Hall data. Results show that, in addition to ignoring parallel conduction, the approximations of conventional Hall data analysis have a further inadequacy for p-type InAs, in that the high electron to hole mobility ratio in InAs is not taken into account. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Electrical characterization of InAs thin films

International Nuclear Information System (INIS)

Botha, L.; Shamba, P.; Botha, J.R.

2008-01-01

It is known that parallel conduction as a result of surface and /or interface charge accumulation significantly shields the bulk electrical properties of InAs thin films when characterized using Hall measurements. This parallel conduction in InAs can be modeled by using the two-layer model of Nedoluha and Koch [Zeitschrift fuer Physik 132, 608 (1952)]; where an InAs epilayer is treated as consisting of two conductors connected in parallel viz. a bulk and a surface layer. Here, this two-layer model is used to simulate Hall coefficient and conductivity data of InAs thin films ranging from strongly n-doped (n=10 18 cm -3 ) to strongly p-doped (p∝10 19 cm -3 ) material. Conventional Hall approximations, i.e. those that assume uniform conduction from a single band, are then used to predict the apparent carrier concentration and mobility that will be determined from conventional Hall measurements, with the aim of illustrating the error of such a simplified analysis of InAs Hall data. Results show that, in addition to ignoring parallel conduction, the approximations of conventional Hall data analysis have a further inadequacy for p-type InAs, in that the high electron to hole mobility ratio in InAs is not taken into account. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Ultrahigh broadband photoresponse of SnO2 nanoparticle thin film/SiO2/p-Si heterojunction.

Science.gov (United States)

Ling, Cuicui; Guo, Tianchao; Lu, Wenbo; Xiong, Ya; Zhu, Lei; Xue, Qingzhong

2017-06-29

The SnO 2 /Si heterojunction possesses a large band offset and it is easy to control the transportation of carriers in the SnO 2 /Si heterojunction to realize high-response broadband detection. Therefore, we investigated the potential of the SnO 2 nanoparticle thin film/SiO 2 /p-Si heterojunction for photodetectors. It is demonstrated that this heterojunction shows a stable, repeatable and broadband photoresponse from 365 nm to 980 nm. Meanwhile, the responsivity of the device approaches a high value in the range of 0.285-0.355 A W -1 with the outstanding detectivity of ∼2.66 × 10 12 cm H 1/2 W -1 and excellent sensitivity of ∼1.8 × 10 6 cm 2 W -1 , and its response and recovery times are extremely short (oxide or oxide/Si based photodetectors. In fact, the photosensitivity and detectivity of this heterojunction are an order of magnitude higher than that of 2D material based heterojunctions such as (Bi 2 Te 3 )/Si and MoS 2 /graphene (photosensitivity of 7.5 × 10 5 cm 2 W -1 and detectivity of ∼2.5 × 10 11 cm H 1/2 W -1 ). The excellent device performance is attributed to the large Fermi energy difference between the SnO 2 nanoparticle thin film and Si, SnO 2 nanostructure, oxygen vacancy defects and thin SiO 2 layer. Consequently, practical highly-responsive broadband PDs may be actualized in the future.

Fabrication of 94Zr thin target for recoil distance doppler shift method of lifetime measurement

International Nuclear Information System (INIS)

Gupta, C.K.; Rohilla, Aman; Abhilash, S.R.; Kabiraj, D.; Singh, R.P.; Mehta, D.; Chamoli, S.K.

2014-01-01

A thin isotopic 94 Zr target of thickness 520μg/cm 2 has been prepared for recoil distance Doppler shift method (RDM) lifetime measurement by using an electron beam deposition method on tantalum backing of 3.5 mg/cm 2 thickness at Inter University Accelerator Center (IUAC), New Delhi. To meet the special requirement of smoothness of surface for RDM lifetime measurement and also to protect the outer layer of 94 Zr from peeling off, a very thin layer of gold has been evaporated on a 94 Zr target on a specially designed substrate holder. In all, 143 mg of 99.6% enriched 94 Zr target material was utilized for the fabrication of 94 Zr targets. The target has been successfully used in a recent RDM lifetime measurement experiment at IUAC

Fabrication of 94Zr thin target for recoil distance doppler shift method of lifetime measurement

Science.gov (United States)

Gupta, C. K.; Rohilla, Aman; Abhilash, S. R.; Kabiraj, D.; Singh, R. P.; Mehta, D.; Chamoli, S. K.

2014-11-01

A thin isotopic 94Zr target of thickness 520 μg /cm2 has been prepared for recoil distance Doppler shift method (RDM) lifetime measurement by using an electron beam deposition method on tantalum backing of 3.5 mg/cm2 thickness at Inter University Accelerator Center (IUAC), New Delhi. To meet the special requirement of smoothness of surface for RDM lifetime measurement and also to protect the outer layer of 94Zr from peeling off, a very thin layer of gold has been evaporated on a 94Zr target on a specially designed substrate holder. In all, 143 mg of 99.6% enriched 94Zr target material was utilized for the fabrication of 94Zr targets. The target has been successfully used in a recent RDM lifetime measurement experiment at IUAC.

Semiconductor thin films directly from minerals—study of structural, optical, and transport characteristics of Cu2O thin films from malachite mineral and synthetic CuO

International Nuclear Information System (INIS)

Balasubramaniam, K.R.; Kao, V.M.; Ravichandran, J.; Rossen, P.B.; Siemons, W.; Ager, J.W.

2012-01-01

We demonstrate the proof-of-concept of using an abundantly occurring natural ore, malachite (Cu 2 CO 3 (OH) 2 ) to directly yield the semiconductor Cu 2 O to be used as an active component of a functional thin film based device. Cu 2 O is an archetype hole-conducting semiconductor that possesses several interesting characteristics particularly useful for solar cell applications, including low cost, non-toxicity, good hole mobility, large minority carrier diffusion length, and a direct energy gap ideal for efficient absorption. In this article, we compare the structural, optical, and electrical transport characteristics of Cu 2 O thin films grown from the natural mineral malachite and synthetic CuO targets. Growth from either source material results in single-phase, fully epitaxial cuprous oxide thin films as determined by x-ray diffraction. The films grown from malachite have strong absorption coefficients ( 10 4 cm −1 ), a direct allowed optical bandgap ( 2.4 eV), and majority carrier hole mobilities ( 35 cm 2 V −1 s −1 at room temperature) that compare well with films grown from the synthetic target as well as with previously reported values. Our work demonstrates that minerals could be useful to directly yield the active components in functional devices and suggests a route for the exploration of low cost energy conversion and storage technologies. - Highlights: ► Semiconductor thin films directly from minerals ► Chemistry and structure evolution of the films obtained from mineral target is very similar to that films obtained from high-purity synthetic targets. ► Quite interestingly, transport and optical characteristics are also found to be similar.

Mass productions of thin film silicon PV modules

International Nuclear Information System (INIS)

Tawada, Y.; Yamagishi, H.; Yamamoto, K.

2003-01-01

Mass production technologies of a-Si single junction and a-Si/poly-Si hybrid modules with stable 8% and 10% efficiency were developed in the Shiga factory of Kaneka Corporation. Kaneka instituted Kaneka Solartech Corporation (KST) as a subsidiary company of 100% shareholder and invested 20 MW production plant in Toyooka City in 1999. There are fully automatic thin film fabrication equipments. KST started the manufacturing amorphous silicon PV modules in 1999 and those of hybrid type PV modules in 2001. The largest size glass substrates used for these modules are 95x98 cm and variable size of modules are being produced by cutting these large area base modules. Recent production yields are higher than 98%. Production technologies of a-Si, thin c-Si and solar cells, performances of modules, applications to the rooftop PV systems will be presented. We estimate the production cost of a-Si solar modules and a-Si/thin c-Si hybrid solar modules. The future business plan of our new type solar modules and our production lines will be discussed. (author)

CM : becoming a technology firm

NARCIS (Netherlands)

Burg, van J.C.; Reymen, I.M.M.J.; Dolmans, S.A.M.

2011-01-01

Founded in 2000 as a Short Message Service (SMS) marketing company for discos (clubs), CM evolved into a technology provider for SMS services. By 2008, CM was market leader in The Netherlands, a position won by offering high quality services at low prices. In 2010, the founders of the company were

Thin film preparation of semiconducting iron pyrite

Science.gov (United States)

Smestad, Greg P.; Ennaoui, Ahmed; Fiechter, Sebastian; Hofmann, Wolfgang; Tributsch, Helmut; Kautek, Wolfgang

1990-08-01

Pyrite (Fe52) has been investigated as a promising new absorber material for thin film solar cell applications because of its high optical absorption coefficient of 1OL cm1, and its bandgap of 0.9 to 1.0 eV. Thin layers have been prepared by Metal Organic Chemical Vapor Deposition, MOCVD, Chemical Spray Pyrolysis, CSP, Chemical Vapor Transport, CVT, and Sulfurization of Iron Oxide films, 510. It is postulated that for the material FeS2, if x is not zero, a high point defect concentration results from replacing 2 dipoles by single S atoms. This causes the observed photovoltages and solar conversion efficiencies to be lower than expected. Using the Fe-O-S ternary phase diagram and the related activity plots, a thermodynamic understanding is formulated for the resulting composition of each of these types of films. It is found that by operating in the oxide portion of the phase diagram, the resulting oxidation state favors pyrite formation over FeS. By proper orientation of the grains relative to the film surface, and by control of pinholes and stoichiometry, an efficient thin film photovolatic solar cell material could be achieved.

Abnormal electrical resistivity in γ-TiAl thin films deposited by magnetron sputtering

International Nuclear Information System (INIS)

Alford, T.L.; Gadre, K.S.; Kim, H.C.; Deevi, S.C.

2003-01-01

Thin films of γ-TiAl are being considered as a potential conductor and/or diffusion barrier for high temperature electronics because of their high melting points and high oxidation resistance. However, it is not possible to form pure γ-TiAl thin films by thermal annealing of Al/Ti bilayers. This study, however, demonstrates the formation of γ-TiAl thin films by dc magnetron sputtering of a compound target. X-ray diffractometry and Rutherford backscattering spectrometry analyses confirm the γ-TiAl phase formation, composition, and thermal stability in vacuum (up to 700 deg. C, 1 h) on SiO 2 . Four-point probe resistivity measurements in vacuum show an initial increase in the resistivity with temperature up to transition temperature for the γ-TiAl thin films. At higher temperatures a decrease in resistivity with additional heating (i.e., negative temperature coefficient of resistivity, TCR) is seen. The values of dρ/dT are typically on the order of -0.32 μΩ cm/ deg. C between 200 and 550 deg. C. At the highest temperature, a minimum value of resistivity of ∼13 μΩ cm is obtained; this value is about one half the value of bulk TiAl at room temperatures. The negative TCR, low resistivity values at high temperatures, and temperature stability are not typically seen in bulk TiAl. This abnormal electrical property is explained using a modified model for a thermally activated polaron-hopping mechanism

Comparative study on substitution effects in BiFeO{sub 3} thin films fabricated on FTO substrates by chemical solution deposition

Energy Technology Data Exchange (ETDEWEB)

Xue, Xu; Tan, Guoqiang, E-mail: tan3114@163.com; Hao, Hangfei; Ren, Huijun

2013-10-01

Pure BiFeO{sub 3} (BFO), BiFe{sub 0.97}Co{sub 0.03}O{sub 3−δ} (BFCO) and Bi{sub 0.90}Gd{sub 0.10}Fe{sub 0.97}Co{sub 0.03}O{sub 3−δ} (BGFCO) thin films were successfully deposited on FTO substrates by chemical solution deposition technique. The field emission scanning electron microscope reveals that the surface morphology of the BGFCO thin film becomes more compact and uniform than that of the other two films. A slight lattice distortion is created in the BFCO thin film, whereas 10% Gd doping gives rise to tetragonal phase transition and (1 1 0) preferentially oriented film texture for the BGFCO thin film, as evidenced by Raman scattering spectra and X-ray diffraction analyses. X-ray photoelectron spectroscopy analyses clarify that Co-doping results in the increase of oxygen vacancy concentration in the BFCO film, while further introduction of Gd into the BFCO lattice can decrease oxygen vacancy concentration, and the concentrations of Fe{sup 2+} ions in the BFCO and BGFCO thin films are less than that in the BFO counterpart. The BFCO film shows the improved remanent polarization (P{sub r}) of 11.2 μC/cm{sup 2} compared with that of 1.4 μC/cm{sup 2} for the BFO film. The high breakdown strength, low leakage current density in the high electric filed, improved dielectric properties as well as the increased stereochemical activity of Bi ion lone electron pair of the BGFCO thin film all together contribute to the giant P{sub r} of 139.6 μC/cm{sup 2} at room temperature.

A Raman Study of Carbonates and Organic Contents in Five CM Chondrites

Science.gov (United States)

Chan, Q. H. S.; Zolensky, M. E.; Bodnar, R. J.; Farley, C.; Cheung, J. C. H.

2016-01-01

Carbonates comprise the second most abundant class of carbon-bearing phases in carbonaceous chondrites after organic matter (approximately 2 wt.%), followed by other C-bearing phases such as diamond, silicon carbide, and graphite. Therefore, understanding the abundances of carbonates and the associated organic matter provide critical insight into the genesis of major carbonaceous components in chondritic materials. Carbonates in CM chondrites mostly occur as calcite (of varying composition) and dolomite. Properly performed, Raman spectroscopy provides a non-destructive technique for characterizing meteorite mineralogy and organic chemistry. It is sensitive to many carbonaceous phases, allows the differentiation of organic from inorganic materials, and the interpretation of their spatial distribution. Here, with the use of Raman spectroscopy, we determine the structure of the insoluble organic matter (IOM) in the matrix and carbonate phases in five CM chondrites: Jbilet Winselwan, Murchison, Nogoya, Santa Cruz, and Wisconsin Range (WIS) 91600, and interpret the relative timing of carbonate precipitation and the extent of the associated alteration events.

Effect of boron implantation on the electrical and photoelectrical properties of e-beam deposited Ag-In-Se thin films

International Nuclear Information System (INIS)

Colakoglu, T; Parlak, M; Kulakci, M; Turan, R

2008-01-01

In this study, e-beam evaporated Ag-In-Se (AIS) thin films were doped by the implantation of boron (B) ions at 75 keV with a dose of 1 x 10 15 ions cm -2 and a subsequent annealing process was applied to the doped AIS films at different temperatures under nitrogen atmosphere. The effects of implantation and annealing on the electrical and photoelectrical properties of AIS thin films were investigated through temperature dependent conductivity, spectral photoresponse and photoconductivity measurements under different illumination intensities. The electrical conductivity measurements showed that the room temperature conductivity values were determined as 2.4 x 10 -7 (Ω cm) -1 , 1.7 x 10 -6 (Ω cm) -1 and 8.9 x 10 -5 (Ω cm) -1 for B-doped films (B0), B-doped and annealed films at 200 deg. C (B2) and at 300 deg. C (B3), respectively. It was observed that the electrical conductivity improved as the annealing temperature increased up to 400 deg. C at which the AIS thin films showed degenerate semiconductor behaviour. The spectral distribution of the photoresponse curves indicated three local maxima located at 1.63, 1.79 and 2.01 eV for B0 type films, 1.65, 1.87 and 2.07 eV for B2 type films and 1.73, 2.02 and 2.32 eV for B3 type films at room temperature. These three different energy values were ascribed to the splitting of the valence band due to spin-orbit interaction and crystalline lattice field effects. The first energy values of each set were determined to be energy band gaps of the AIS thin films. The photoconductivity measurements as a function of temperature and illumination intensity were performed on the B-doped AIS thin films in order to determine the nature of recombination processes in the films. The photoconductivity values were found to be thermally quenched for all types of thin films and the variation of photocurrent as a function of illumination intensity showed that the dependence of photocurrent on the intensity was supralinear. The two

Podocyte Depletion in Thin GBM and Alport Syndrome.

Science.gov (United States)

Wickman, Larysa; Hodgin, Jeffrey B; Wang, Su Q; Afshinnia, Farsad; Kershaw, David; Wiggins, Roger C

2016-01-01

The proximate genetic cause of both Thin GBM and Alport Syndrome (AS) is abnormal α3, 4 and 5 collagen IV chains resulting in abnormal glomerular basement membrane (GBM) structure/function. We previously reported that podocyte detachment rate measured in urine is increased in AS, suggesting that podocyte depletion could play a role in causing progressive loss of kidney function. To test this hypothesis podometric parameters were measured in 26 kidney biopsies from 21 patients aged 2-17 years with a clinic-pathologic diagnosis including both classic Alport Syndrome with thin and thick GBM segments and lamellated lamina densa [n = 15] and Thin GBM cases [n = 6]. Protocol biopsies from deceased donor kidneys were used as age-matched controls. Podocyte depletion was present in AS biopsies prior to detectable histologic abnormalities. No abnormality was detected by light microscopy at 70% podocyte depletion. Low level proteinuria was an early event at about 25% podocyte depletion and increased in proportion to podocyte depletion. These quantitative data parallel those from model systems where podocyte depletion is the causative event. This result supports a hypothesis that in AS podocyte adherence to the GBM is defective resulting in accelerated podocyte detachment causing progressive podocyte depletion leading to FSGS-like pathologic changes and eventual End Stage Kidney Disease. Early intervention to reduce podocyte depletion is projected to prolong kidney survival in AS.

Wavelength-tunable colloidal quantum dot laser on ultra-thin flexible glass

Energy Technology Data Exchange (ETDEWEB)

Foucher, C.; Guilhabert, B.; Laurand, N.; Dawson, M. D. [Institute of Photonics, SUPA, University of Strathclyde, Glasgow (United Kingdom)

2014-04-07

A mechanically flexible and wavelength-tunable laser with an ultra-thin glass membrane as substrate is demonstrated. The optically pumped hybrid device has a distributed feedback cavity that combines a colloidal quantum dot gain film with a grating-patterned polymeric underlayer, all on a 30-μm thick glass sheet. The total thickness of the structure is only 75 μm. The hybrid laser has an average threshold fluence of 450 ± 80 μJ/cm{sup 2} (for 5-ns excitation pulses) at an emitting wavelength of 607 nm. Mechanically bending the thin-glass substrate enables continuous tuning of the laser emission wavelength over an 18-nm range, from 600 nm to 618 nm. The correlation between the wavelength tunability and the mechanical properties of the thin laser structure is verified theoretically and experimentally.

Growth and applications of superconducting Y-Ba-Cu-O thin films

International Nuclear Information System (INIS)

Pinto, R.

1991-01-01

This paper attempt to highlight the important PVD techniques such as evaporation, sputtering, ion beam deposition and excimer laser ablation for the preparation of superconducting YBaCuO thin films. Since enormous amount of work has been published over the last few years, this review is not comprehensive even in PVD techniques. In the area of applications for electronics, thin film appear to be much more promising than bulk high T c superconductors. Already high J c values in the region of 4 x 10 6 A cm -2 have been realized in thin films. Resonators and transmission lines have been fabricated using 123 films showing a transmission loss significantly lower than that of copper at 77 degrees K at X-band frequencies. This review will discuss some of the important electronic applications feasible with 123 films

Dithienocoronenediimide-based copolymers as novel ambipolar semiconductors for organic thin-film transistors.

Science.gov (United States)

Usta, Hakan; Newman, Christopher; Chen, Zhihua; Facchetti, Antonio

2012-07-17

A new class of ambipolar donor-acceptor π-conjugated polymers based on a dithienocoronenediimide core is presented. Solution-processed top-gate/bottom-contact thin film transistors (TFTs) exhibit electron and hole mobilities of up to 0.30 cm(2)/V·s and 0.04 cm(2)/V·s, respectively, which are the highest reported to date for an ambipolar polymer in ambient conditions. The polymers presented here are the first examples of coronenediimide-based semiconductors showing high organic TFT performances. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Gas permeability of thin polyimide foils prepared by in-situ polymerisation

International Nuclear Information System (INIS)

Stolarz, Anna; Varlam, Mihai; Wellum, Roger

2008-01-01

The entrance windows to the gas detector chambers as well as to the target containers used in high-energy and high-intensity accelerators must be as thin as possible to minimise energy losses of the particles used in astrophysics and nuclear physics studies. Because of their good physical properties, polyimide foils are often considered as suitable material for such windows, but commercially available foils, having a thickness greater than 7-8 μm (>1 mg/cm 2 ), would cause energy losses of particles significant for some nuclear reactions studied. Foils prepared by in-situ polymerisation can, however, be as thin as 0.07 μm (∼10 μg/cm 2 ). The permeability of 4 μm foils produced by in-situ polymerisation has been measured at room temperature for He and Ar. For He measurements were performed in the pressure range of 4-70 mbar and for Ar in the range of 20-140 mbar and the permeability was found to be in good agreement with the values published for the thicker commercial foils

Investigation of $pp\\bar$ Events at 540 GeV c.m. Energy with a Streamer Chamber Detection System

CERN Multimedia

2002-01-01

The SPS Collider offers an opportunity to study hadronically-produced events in an entirely new energy domain. The UA5 Collaboration is investigating many features of the physics of 540 GeV proton-antiproton collisions, including 1) charged particle production; pseudorapidity and multiplicity distributions 2) photon production; pseudorapidity distributions 3) charged-charged and charged-neutral particle correlations 4) neutral and charged strange particle production and their p^t-distributions 5)~~a special study of high multiplicity events; search for Centauro events,~etc. .in;.sk; The basic detector consists of two large (6m) streamer chambers, triggered by hodoscopes at either end and at 90|0, and viewed by cameras via image intensifiers. Charged tracks can be observed down to 3/4|0, and hence over most of the pseudorapidity range (!@h!$<$5.0) in which they are produced; photons are observed over the same pseudorapidity range. Neutral and charged particle decays are identified over !@h!$<$3. New comp...

Accuracy of free energies of hydration using CM1 and CM3 atomic charges.

Science.gov (United States)

Udier-Blagović, Marina; Morales De Tirado, Patricia; Pearlman, Shoshannah A; Jorgensen, William L

2004-08-01

Absolute free energies of hydration (DeltaGhyd) have been computed for 25 diverse organic molecules using partial atomic charges derived from AM1 and PM3 wave functions via the CM1 and CM3 procedures of Cramer, Truhlar, and coworkers. Comparisons are made with results using charges fit to the electrostatic potential surface (EPS) from ab initio 6-31G* wave functions and from the OPLS-AA force field. OPLS Lennard-Jones parameters for the organic molecules were used together with the TIP4P water model in Monte Carlo simulations with free energy perturbation theory. Absolute free energies of hydration were computed for OPLS united-atom and all-atom methane by annihilating the solutes in water and in the gas phase, and absolute DeltaGhyd values for all other molecules were computed via transformation to one of these references. Optimal charge scaling factors were determined by minimizing the unsigned average error between experimental and calculated hydration free energies. The PM3-based charge models do not lead to lower average errors than obtained with the EPS charges for the subset of 13 molecules in the original study. However, improvement is obtained by scaling the CM1A partial charges by 1.14 and the CM3A charges by 1.15, which leads to average errors of 1.0 and 1.1 kcal/mol for the full set of 25 molecules. The scaled CM1A charges also yield the best results for the hydration of amides including the E/Z free-energy difference for N-methylacetamide in water. Copyright 2004 Wiley Periodicals, Inc.

Substrate decoration for improvement of current-carrying capabilities of YBa{sub 2}Cu{sub 3}O{sub x} thin films

Energy Technology Data Exchange (ETDEWEB)

Khoryushin, Alexey V., E-mail: khoryushin@ya.ru [Department of Physics, Technical University of Denmark, DTU Building 309, Kgs. Lyngby DK-2800 (Denmark); Mozhaev, Peter B.; Mozhaeva, Julia E. [Department of Physics, Technical University of Denmark, DTU Building 309, Kgs. Lyngby DK-2800 (Denmark); Bdikin, Igor K. [Department of Mechanical Engineering, Centre for Mechanical Technology and Automation, University of Aveiro, 3810-193 Aveiro (Portugal); Zhao, Yue [Department of Energy Conversion and Storage, Technical University of Denmark, DK-4000 Roskilde (Denmark); Andersen, Niels H.; Jacobsen, Claus S.; Hansen, Jørn Bindslev [Department of Physics, Technical University of Denmark, DTU Building 309, Kgs. Lyngby DK-2800 (Denmark)

2013-03-15

Highlights: ► Effects of substrate decoration on properties of YBCO thin films were studied. ► Y{sub 2}O{sub 3} nanoparticles, ultra-thin Y{sub 2}O{sub 3} and Y:ZrO{sub 2} layers were used as decoration layer. ► Decoration improves j{sub C} (5 T and 50 K) up to 0.97 MA/cm{sup 2} vs. 0.76 MA/cm{sup 2} for a reference film. ► Ultra-thin layer of yttria and yttria nanoparticles have a similar effect on YBCO. ► Y{sub 2}O{sub 3} decoration results in power law coefficient α = 0.3 vs. α = 0.4 for a reference film. -- Abstract: The effects of substrate decoration with yttria and Y:ZrO{sub 2} on the structural and electrical properties of the YBa{sub 2}Cu{sub 3}O{sub x} (YBCO) thin films are studied. The films were deposited on (LaAlO{sub 3}){sub 3}–(Sr{sub 2}AlTaO{sub 8}){sub 7} substrates by pulsed laser deposition. Two different structures of decoration layer were applied, a template layer of nanoparticles and an uniform ultra-thin layer. Significant improvement of current-carrying capabilities was observed, especially at high external magnetic fields. Structural studies of these films reveal the presence of extended linear defects in the YBCO matrix. The formation of these structures is attributed to seeding of randomly oriented YBCO grains due to suppression of epitaxy in the very beginning of the deposition. The films of both kinds of decoration layers show nearly the same improvement of j{sub C} over the reference film at 77 and 50 K: j{sub C} (5T and 50 K) reaches 0.92 and 0.97 MA/cm{sup 2} for uniform and template decoration layers. At 5 and 20 K the effect of template decoration layers is more beneficial: j{sub C} (5T and 20 K) values are 3.5 and 4.1 MA/cm{sup 2}, j{sub C} (5T and 5 K) values are 6.4 and 7.9 MA/cm{sup 2}, for uniform and template decoration layers, respectively.

Fabrication of high quality Cu2SnS3 thin film solar cell with 1.12% power conversion efficiency obtain by low cost environment friendly sol-gel technique

Science.gov (United States)

Chaudhari, J. J.; Joshi, U. S.

2018-03-01

Cu2SnS3 (CTS) is an emerging ternery chalcogenide material with great potential application in thin film solar cells. We present here high quality Cu2SnS3 thin films using a facile spin coating method. The as deposited films of CTS were sulphurized in a graphite box using tubular furnace at 520 °C for 60 min at the rate of 2.83 °C min-1 in argon atmosphere. X-ray diffraction (XRD) and Raman spectroscopy studies confirm tetragonal phase and absence of any secondary phase in sulphurized CTS thin films. X-ray photoelectron spectroscopy (XPS) demonstrates that Cu and Sn are in +1 and +4 oxidation state respectively. Surface morphology of CTS films were analyzed by field emission scanning electron microscope and atomic force microscope (AFM), which revealed a smooth surface with roughness (RMS) of 6.32 nm for sulphurized CTS film. Hall measurements confirmed p-type conductivity with hole concentartion of sulphurized CTS thin film is of 6.5348 × 1020 cm-3. UV-vis spectra revealed a direct energy band gap varies from 1.45 eV to 1.01 eV for as-deposited and sulphurized CTS thin film respectively. Such band gap values are optimum for semiconductor material as an absorber layer of thin film solar cell. The CTS thin film solar cell had following structure: SLG/FTO/ZnO/CTS/Al with short circuit current density of (Jsc) of 11.6 mA cm-2, open circuit voltage (Voc) of 0.276 V, active area of 0.16 cm2, fill factor (FF) of 35% and power conversion efficiency of 1.12% under AM 1.5 (100 mW cm-2) illumination in simulated standard test conditions.

Electrochemical reaction of lithium with orthorhombic bismuth tungstate thin films fabricated by radio-frequency sputtering

International Nuclear Information System (INIS)

Li Chilin; Sun Ke; Yu Le; Fu Zhengwen

2009-01-01

Bi 2 WO 6 thin films with fast deposition rate have been fabricated by radio-frequency (R.F.) sputtering deposition, and are used as positive electrodes in rechargeable thin film lithium batteries. An initial discharge capacity of 113 μAh/cm 2 -μm is obtainable for Bi 2 WO 6 film electrode with good capacity reversibility. A multiple-center reactive mechanism associated with both Bi 3+ /Bi 0 and W 6+ /W x+ (x 2 WO 6 electrochemical performance with those of Bi 2 O 3 and WO 3 thin films. A possible explanation about smooth capacity loss of Bi 2 WO 6 after long-term cycling is suggested from the incomplete reaction of Bi component. The advantages of Bi 2 WO 6 thin films over the singer-center Bi 2 O 3 or WO 3 thin films are shown in both the aspects of volumetric capacity and cycling life.

Solution processible Cu{sub 2}SnS{sub 3} thin films for cost effective photovoltaics: Characterization

Energy Technology Data Exchange (ETDEWEB)

Dias, Sandra, E-mail: dias.sandra123@gmail.com; Murali, Banavoth; Krupanidhi, S.B.

2015-11-01

Thin films of Cu{sub 2}SnS{sub 3} (CTS) were deposited by the facile solution processed sol–gel route followed by a low-temperature annealing. The Cu–Sn-thiourea complex formation was analysed using Fourier Transform Infrared spectrophotometer (FTIR). The various phase transformations and the deposition temperature range for the initial precursor solution was determined using Thermogravimetric analysis (TGA) and Differential Scanning Calorimetry (DSC). X-Ray Diffraction (XRD) studies revealed the tetragonal phase formation of the CTS annealed films. Raman spectroscopy studies further confirmed the tetragonal phase formation and the absence of any deterioratory secondary phases. The morphological investigations and compositional analysis of the films were determined using Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) respectively. Atomic Force Microscopy (AFM) was used to estimate the surface roughness of 1.3 nm. The absorption coefficient was found to be 10{sup 4} cm{sup −1} and bandgap 1.3 eV which qualifies CTS to be a potential candidate for photovoltaic applications. The refractive index, extinction coefficient and relative permittivity of the film were measured by Spectroscopic ellipsometry. Hall effect measurements, indicated the p type nature of the films with a hole concentration of 2 × 10{sup 18} cm{sup −3}, electrical conductivity of 9 S/cm and a hole mobility of 29 cm{sup 2}/V. The properties of CTS as deduced from the current study, present CTS as a potential absorber layer material for thin film solar cells. - Highlights: • Cu{sub 2}SnS{sub 3} thin films have been synthesized by spin coating of a precursor solution. • The Cu–Sn-thiourea complex precursor was analysed. • The structural, optical and electrical properties of the thin films were studied. • Totally 24 infra-red, 30 optical, 29 Raman and 30 hyper Raman modes are active. • Refractive index, extinction coefficient and relative

NUMERICAL MODELING OF THE 2009 IMPACT EVENT ON JUPITER

Energy Technology Data Exchange (ETDEWEB)

Pond, Jarrad W. T.; Palotai, Csaba; Gabriel, Travis; Harrington, Joseph; Rebeli, Noemi [Planetary Sciences Group, Department of Physics, University of Central Florida, Orlando, FL 32816-2385 (United States); Korycansky, Donald G., E-mail: jarradpond@gmail.com [Department of Earth and Planetary Science, University of California, Santa Cruz, CA 95064 (United States)

2012-02-01

We have investigated the 2009 July impact event on Jupiter using the ZEUS-MP 2 three-dimensional hydrodynamics code. We studied the impact itself and the following plume development. Eight impactors were considered: 0.5 km and 1 km porous ({rho} = 1.760 g cm{sup -3}) and non-porous ({rho} = 2.700 g cm{sup -3}) basalt impactors, and 0.5 km and 1 km porous ({rho} = 0.600 g cm{sup -3}) and non-porous ({rho} = 0.917 g cm{sup -3}) ice impactors. The simulations consisted of these bolides colliding with Jupiter at an incident angle of {theta} = 69 Degree-Sign from the vertical and with an impact velocity of v = 61.4 km s{sup -1}. Our simulations show the development of relatively larger, faster plumes created after impacts involving 1 km diameter bodies. Comparing simulations of the 2009 event with simulations of the Shoemaker-Levy 9 (SL9) events reveals a difference in plume development, with the higher incident angle of the 2009 impact leading to a shallower terminal depth and a smaller and slower plume. We also studied the amount of dynamical chaos present in the simulations conducted at the 2009 incident angle. Compared to the chaos of the SL9 simulations, where {theta} Almost-Equal-To 45 Degree-Sign , we find no significant difference in chaos at the higher 2009 incident angle.

Enhanced electrical properties of oxide semiconductor thin-film transistors with high conductivity thin layer insertion for the channel region

Energy Technology Data Exchange (ETDEWEB)

Nguyen, Cam Phu Thi; Raja, Jayapal; Kim, Sunbo; Jang, Kyungsoo; Le, Anh Huy Tuan; Lee, Youn-Jung; Yi, Junsin, E-mail: junsin@skku.edu

2017-02-28

Highlights: • The characteristics of thin film transistors using double active layers are examined. • Electrical characteristics have been improved for the double active layers devices. • The total trap density can be decreased by insert-ion of ultrathin ITO film. - Abstract: This study examined the performance and the stability of indium tin zinc oxide (ITZO) thin film transistors (TFTs) by inserting an ultra-thin indium tin oxide (ITO) layer at the active/insulator interface. The electrical properties of the double channel device (ITO thickness of 5 nm) were improved in comparison with the single channel ITZO or ITO devices. The TFT characteristics of the device with an ITO thickness of less than 5 nm were degraded due to the formation of an island-like morphology and the carriers scattering at the active/insulator interface. The 5 nm-thick ITO inserted ITZO TFTs (optimal condition) exhibited a superior field effect mobility (∼95 cm{sup 2}/V·s) compared with the ITZO-only TFTs (∼34 cm{sup 2}/V·s). The best characteristics of the TFT devices with double channel layer are due to the lowest surface roughness (0.14 nm) and contact angle (50.1°) that result in the highest hydrophicility, and the most effective adhesion at the surface. Furthermore, the threshold voltage shifts for the ITO/ITZO double layer device decreased to 0.80 and −2.39 V compared with 6.10 and −6.79 V (for the ITZO only device) under positive and negative bias stress, respectively. The falling rates of E{sub A} were 0.38 eV/V and 0.54 eV/V for the ITZO and ITO/ITZO bi-layer devices, respectively. The faster falling rate of the double channel devices suggests that the trap density, including interface trap and semiconductor bulk trap, can be decreased by the ion insertion of a very thin ITO film into the ITZO/SiO{sub 2} reference device. These results demonstrate that the double active layer TFT can potentially be applied to the flat panel display.

Effects of substrate temperature on structural and electrical properties of SiO2-matrix boron-doped silicon nanocrystal thin films

International Nuclear Information System (INIS)

Huang, Junjun; Zeng, Yuheng; Tan, Ruiqin; Wang, Weiyan; Yang, Ye; Dai, Ning; Song, Weijie

2013-01-01

In this work, silicon-rich SiO 2 (SRSO) thin films were deposited at different substrate temperatures (T s ) and then annealed by rapid thermal annealing to form SiO 2 -matrix boron-doped silicon-nanocrystals (Si-NCs). The effects of T s on the micro-structure and electrical properties of the SiO 2 -matrix boron-doped Si-NC thin films were investigated using Raman spectroscopy and Hall measurements. Results showed that the crystalline fraction and dark conductivity of the SiO 2 -matrix boron-doped Si-NC thin films both increased significantly when the T s was increased from room temperature to 373 K. When the T s was further increased from 373 K to 676 K, the crystalline fraction of 1373 K-annealed thin films decreased from 52.2% to 38.1%, and the dark conductivity reduced from 8 × 10 −3 S/cm to 5.5 × 10 −5 S/cm. The changes in micro-structure and dark conductivity of the SiO 2 -matrix boron-doped Si-NC thin films were most possibly due to the different amount of Si-O 4 bond in the as-deposited SRSO thin films. Our work indicated that there was an optimal T s , which could significantly increase the crystallization and conductivity of Si-NC thin films. Also, it was illumined that the low-resistivity SiO 2 -matrix boron-doped Si-NC thin films can be achieved under the optimal substrate temperatures, T s .

Effects of viscosity on power and hand injection of iso-osmolar iodinated contrast media through thin catheters.

Science.gov (United States)

Zhang, James J; Hogstrom, Barry; Malinak, Jiri; Ikei, Nobuhiro

2016-05-01

It can be challenging to achieve adequate vessel opacification during percutaneous coronary interventions when using thin catheters, hand injection, and iso-osmolar contrast media (CM) such as iodixanol (Visipaque™). To explore these limitations and the possibility to overcome them with iosimenol, a novel CM. Three X-ray contrast media with different concentrations were used in this study. A series of in vitro experiments established the relationship between injection pressure and flow rate in angiography catheters under various conditions. The experiments were conducted with power and hand injections and included a double-blind evaluation of user perception. By using hand injection, it was generally not possible to reach a maximum injection pressure exceeding 50 psi. The time within which volunteers were able to complete the injections, the area under the pressure-time curve (AUC), and assessment of ease of injection all were in favor of iosimenol compared with iodixanol, especially when using the 4F thin catheter. Within the pressure ranges tested, the power injections demonstrated that the amount of iodine delivered at a fixed pressure was strongly related to viscosity but unrelated to iodine concentration. There are substantial limitations to the amount of iodine that can be delivered through thin catheters by hand injection when iso-osmolar CM with high viscosity is used. The only viable solution, besides increasing the injection pressure, is to use a CM with lower viscosity, since the cost of increasing the concentration, in terms of increased viscosity and consequent reduction in flow, is too high. Iosimenol, an iso-osmolar CM with lower viscosity than iodixanol might therefore be a better alternative when thinner catheters are preferred, especially when the radial artery is used as the access site. © The Foundation Acta Radiologica 2015.

Development of natively textured surface hydrogenated Ga-doped ZnO-TCO thin films for solar cells via magnetron sputtering

International Nuclear Information System (INIS)

Wang, Fei; Chen, Xin-liang; Geng, Xin-hua; Zhang, De-kun; Wei, Chang-chun; Huang, Qian; Zhang, Xiao-dan; Zhao, Ying

2012-01-01

Highlights: ► Natively textured surface hydrogenated gallium-doped zinc oxide (HGZO) thin films have been deposited via magnetron sputtering on glass substrates. ► The directly deposited HGZO thin films present rough crater-type surface morphology. ► Typical HGZO thin film exhibits a high electron mobility of 41.3 cm 2 /V s and a relative low sheet resistance of ∼7.0 Ω. ► These HGZO thin films have high optical transmittances in the visible and near infrared region (∼380–1100 nm). ► A gradient H 2 growth method for fabricating HGZO thin films has been proposed in magnetron sputtering process. - Abstract: The main purposes are to obtain high quality transparent conductive oxide (TCO) based on zinc oxide (ZnO) thin films with high optical transparency in the visible and near infrared spectral range, high electrical conductivity and good light-scattering capability to enhance the path of the light inside the Si-based thin film solar cells. Natively textured surface hydrogenated gallium-doped ZnO (HGZO) thin films have been deposited via pulsed direct current (DC) magnetron sputtering on glass substrates at a substrate temperature of 553 K. These natively textured HGZO thin films exhibit high optical transmittance (over 80%) in the visible and near infrared region (λ = 380–1100 nm) and excellent electrical properties. The optimized HGZO thin film with crater-type textured surface obtained at the hydrogen flow rate of ∼2.0 sccm exhibits a high electron mobility of 41.3 cm 2 /V s and a relatively low sheet resistance of ∼7.0 Ω. The influences of hydrogen flow rates on the surface morphology, electrical and optical properties of HGZO thin films were investigated in detail. In addition, we put forward a method of gradient H 2 growth technique for fabricating HGZO thin films so as to obtain rough surface structure with good light-scattering capability and high electrical conductivity. “Crater-like” surface feature size and optical transmittance

Properties of laser-crystallized polycrystalline SiGe thin films

Energy Technology Data Exchange (ETDEWEB)

Weizman, Moshe

2008-06-06

In this thesis, structural, electrical, and optical properties of laser-crystallized polycrystalline Si{sub 1-x}Ge{sub x} thin films with 0thin films with 0.3thin films with 0cm{sup -3}, which is roughly independent of the crystallization method and Ge content. The defect density for solid-phase crystallized SiGe films was lower and amounted to N{sub s}=7 x 10{sup 17} cm{sup -3}. - Germanium-rich laser-crystallized poly-SiGe thin films exhibited mostly a broad atypical electric dipole spin resonance (EDSR) signal that was accompanied by a nearly temperature-independent electrical conductivity in the range 20-100 K. - Most likely, the origin of the grain boundary conductance is due to dangling-bond defects and not impurities. Metallic-like conductance occurs when the dangling-bond defect density is above a critical value of about N{sub C} {approx} 10{sup 18} cm{sup -3}. - Laser crystallized poly-Si{sub 1-x}Ge{sub x} thin films with x{>=}0.5 exhibit optical absorption behavior that is characteristic for disordered SiGe, implying that the absorption occurs primarily at the grain boundaries. A sub-band-gap absorption peak was found for

Effect on the properties of ITO thin films in Gamma environment

Science.gov (United States)

Sofi, A. H.; Shah, M. A.; Asokan, K.

2018-04-01

The present study reports the effect of gamma irradiation of varying doses (0-200 kGy) on the physical properties of the indium tin oxide (ITO) thin films. The films were fabricated by thermal evaporation method using indium-tin (InSn) ingots followed by an oxidation in atmosphere at a temperature of 550 °C. X-ray diffraction analysis confirmed the body-centered cubic (BCC) structure corresponds to the ITO thin films, high phase purity and a variation in crystallite size between 30-44 nm. While the optical studies revealed an increase in transmission as well as variation in optical band gap, the electrical studies confirmed n-type semiconductive behavior of the thin films, increase in mobility and a decrease in resistivity from 2.33×10-2 - 9.31×10-4 Ωcm with the increase in gamma dose from 0-200 kGy. The gamma irradiation caused totally electronic excitation and resulted in this modifications. The degenerate electron gas model was considered when attempting to understand the prevalent scattering mechanism in gamma irradiated ITO thin films.

Assessment of doses caused by electrons in thin layers of tissue-equivalent materials, using MCNP.

Science.gov (United States)

Heide, Bernd

2013-10-01

Absorbed doses caused by electron irradiation were calculated with Monte Carlo N-Particle transport code (MCNP) for thin layers of tissue-equivalent materials. The layers were so thin that the calculation of energy deposition was on the border of the scope of MCNP. Therefore, in this article application of three different methods of calculation of energy deposition is discussed. This was done by means of two scenarios: in the first one, electrons were emitted from the centre of a sphere of water and also recorded in that sphere; and in the second, an irradiation with the PTB Secondary Standard BSS2 was modelled, where electrons were emitted from an (90)Sr/(90)Y area source and recorded inside a cuboid phantom made of tissue-equivalent material. The speed and accuracy of the different methods were of interest. While a significant difference in accuracy was visible for one method in the first scenario, the difference in accuracy of the three methods was insignificant for the second one. Considerable differences in speed were found for both scenarios. In order to demonstrate the need for calculating the dose in thin small zones, a third scenario was constructed and simulated as well. The third scenario was nearly equal to the second one, but a pike of lead was assumed to be inside the phantom in addition. A dose enhancement (caused by the pike of lead) of ∼113 % was recorded for a thin hollow cylinder at a depth of 0.007 cm, which the basal-skin layer is referred to in particular. Dose enhancements between 68 and 88 % were found for a slab with a radius of 0.09 cm for all depths. All dose enhancements were hardly noticeable for a slab with a cross-sectional area of 1 cm(2), which is usually applied to operational radiation protection.

OCCURRENCE OF EXTREME SOLAR PARTICLE EVENTS: ASSESSMENT FROM HISTORICAL PROXY DATA

Energy Technology Data Exchange (ETDEWEB)

Usoskin, Ilya G. [Sodankylae Geophysical Observatory (Oulu unit) and Department of Physical Sciences, University of Oulu, FIN-90014 Oulu (Finland); Kovaltsov, Gennady A., E-mail: ilya.usoskin@oulu.fi [Ioffe Physical-Technical Institute of RAS, 194021 St. Petersburg (Russian Federation)

2012-09-20

The probability of occurrence of extreme solar particle events (SPEs) with proton fluence (>30 MeV) F{sub 30} {>=} 10{sup 10} cm{sup -2} is evaluated based on data on the cosmogenic isotopes {sup 14}C and {sup 10}Be in terrestrial archives covering centennial-millennial timescales. Four potential candidates with F{sub 30} = (1-1.5) Multiplication-Sign 10{sup 10} cm{sup -2} and no events with F{sub 30} > 2 Multiplication-Sign 10{sup 10} cm{sup -2} are identified since 1400 AD in the annually resolved {sup 10}Be data. A strong SPE related to the Carrington flare of 1859 AD is not supported by the data. For the last 11,400 years, 19 SPE candidates with F{sub 30} = (1-3) Multiplication-Sign 10{sup 10} cm{sup -2} are found and clearly no event with F{sub 30} > 5 Multiplication-Sign 10{sup 10} cm{sup -2} (50 times the SPE of 1956 February 23) has occurred. These values serve as observational upper limits on the strength of SPEs on the timescale of tens of millennia. Two events, ca. 780 and 1460 AD, appear in different data series making them strong candidates for extreme SPEs. We build a distribution of the occurrence probability of extreme SPEs, providing a new strict observational constraint. Practical limits can be set as F{sub 30} Almost-Equal-To 1, 2-3, and 5 Multiplication-Sign 10{sup 10} cm{sup -2} for occurrence probabilities Almost-Equal-To 10{sup -2}, 10{sup -3}, and 10{sup -4} yr{sup -1}, respectively. Because of the uncertainties, our results should be interpreted as a conservative upper limit on the SPE occurrence near Earth. The mean solar energetic particle (SEP) flux is evaluated as Almost-Equal-To 40 (cm{sup 2} s){sup -1}, in agreement with estimates from lunar rocks. On average, extreme SPEs contribute about 10% to the total SEP fluence.

Atmospheric Pressure Plasma Jet-Assisted Synthesis of Zeolite-Based Low-k Thin Films.

Science.gov (United States)

Huang, Kai-Yu; Chi, Heng-Yu; Kao, Peng-Kai; Huang, Fei-Hung; Jian, Qi-Ming; Cheng, I-Chun; Lee, Wen-Ya; Hsu, Cheng-Che; Kang, Dun-Yen

2018-01-10

Zeolites are ideal low-dielectric constant (low-k) materials. This paper reports on a novel plasma-assisted approach to the synthesis of low-k thin films comprising pure-silica zeolite MFI. The proposed method involves treating the aged solution using an atmospheric pressure plasma jet (APPJ). The high reactivity of the resulting nitrogen plasma helps to produce zeolite crystals with high crystallinity and uniform crystal size distribution. The APPJ treatment also remarkably reduces the time for hydrothermal reaction. The zeolite MFI suspensions synthesized with the APPJ treatment are used for the wet deposition to form thin films. The deposited zeolite thin films possessed dense morphology and high crystallinity, which overcome the trade-off between crystallinity and film quality. Zeolite thin films synthesized using the proposed APPJ treatment achieve low leakage current (on the order of 10 -8 A/cm 2 ) and high Young's modulus (12 GPa), outperforming the control sample synthesized without plasma treatment. The dielectric constant of our zeolite thin films was as low as 1.41. The overall performance of the low-k thin films synthesized with the APPJ treatment far exceed existing low-k films comprising pure-silica MFI.

Calorimetric determination of kQ factors for NE 2561 and NE 2571 ionization chambers in 5 cm x 5 cm and 10 cm x 10 cm radiotherapy beams of 8 MV and 16 MV photons.

Science.gov (United States)

Krauss, Achim; Kapsch, Ralf-Peter

2007-10-21

The relative uncertainty of the ionometric determination of the absorbed dose to water, D(w), in the reference dosimetry of high-energy photon beams is in the order of 1.5% and is dominated by the uncertainty of the calculated chamber- and energy-dependent correction factors k(Q). In the present investigation, k(Q) values were determined experimentally in 5 cm x 5 cm and 10 cm x 10 cm radiotherapy beams of 8 MV and 16 MV bremsstrahlung by means of a water calorimeter operated at 4 degrees C. Ionization chambers of the types NE 2561 and NE 2571 were calibrated directly in the water phantom of the calorimeter. The measurements were carried out at the linear accelerator of the Physikalisch-Technische Bundesanstalt. It is shown that the k(Q) factor of a single ionization chamber can be measured with a standard uncertainty of less than 0.3%. No significant variations of k(Q) were found for the different lateral sizes of the radiation fields used in this investigation.

P-type SnO thin films and SnO/ZnO heterostructures for all-oxide electronic and optoelectronic device applications

Energy Technology Data Exchange (ETDEWEB)

Saji, Kachirayil J. [Nanostructured Materials Research Laboratory, Department of Materials Science & Engineering, University of Utah, Salt Lake City, UT 84112 (United States); Department of Physics, Govt. Victoria College, University of Calicut, Palakkad 678 001 (India); Venkata Subbaiah, Y.P. [Nanostructured Materials Research Laboratory, Department of Materials Science & Engineering, University of Utah, Salt Lake City, UT 84112 (United States); Department of Physics, Yogi Vemana University, Kadapa, Andhra Pradesh 516003 (India); Tian, Kun [Nanostructured Materials Research Laboratory, Department of Materials Science & Engineering, University of Utah, Salt Lake City, UT 84112 (United States); Tiwari, Ashutosh, E-mail: tiwari@eng.utah.edu [Nanostructured Materials Research Laboratory, Department of Materials Science & Engineering, University of Utah, Salt Lake City, UT 84112 (United States)

2016-04-30

Tin monoxide (SnO) is considered as one of the most important p-type oxides available to date. Thin films of SnO have been reported to possess both an indirect bandgap (~ 0.7 eV) and a direct bandgap (~ 2.8 eV) with quite high hole mobility (~ 7 cm{sup 2}/Vs) values. Moreover, the hole density in these films can be tuned from 10{sup 15}–10{sup 19} cm{sup −3} just by controlling the thin film deposition parameters. Because of the above attributes, SnO thin films offer great potential for fabricating modern electronic and optoelectronic devices. In this article, we are reviewing the most recent developments in this field and also presenting some of our own results on SnO thin films grown by pulsed laser deposition technique. We have also proposed a p–n heterostructure comprising of p-type SnO and n-type ZnO which can pave way for realizing next-generation, all-oxide transparent electronic devices. - Highlights: • We reviewed recent developments on p-type SnO thin film research. • Discussed the optical and electrical properties of SnO thin films • Bipolar conduction in SnO is discussed. • Optoelectronic properties of SnO–ZnO composite system are discussed. • Proposed SnO–ZnO heterojunction band structure.

Defect control in room temperature deposited cadmium sulfide thin films by pulsed laser deposition

International Nuclear Information System (INIS)

Hernandez-Como, N.; Martinez-Landeros, V.; Mejia, I.; Aguirre-Tostado, F.S.; Nascimento, C.D.; Azevedo, G. de M; Krug, C.; Quevedo-Lopez, M.A.

2014-01-01

The control of defects in cadmium sulfide thin films and its impact on the resulting CdS optical and electrical characteristics are studied. Sulfur vacancies and cadmium interstitial concentrations in the CdS films are controlled using the ambient pressure during pulsed laser deposition. CdS film resistivities ranging from 10 −1 to 10 4 Ω-cm are achieved. Hall Effect measurements show that the carrier concentration ranges from 10 19 to 10 13 cm −3 and is responsible for the observed resistivity variation. Hall mobility varies from 2 to 12 cm 2 /V-s for the same pressure regime. Although the energy bandgap remains unaffected (∼ 2.42 eV), the optical transmittance is reduced due to the increase of defects in the CdS films. Rutherford back scattering spectroscopy shows the dependence of the CdS films stoichiometry with deposition pressure. The presence of CdS defects is attributed to more energetic species reaching the substrate, inducing surface damage in the CdS films during pulsed laser deposition. - Highlights: • CdS thin films deposited by pulsed laser deposition at room temperature. • The optical, electrical and structural properties were evaluated. • Carrier concentration ranged from 10 19 to 10 13 cm −3 . • The chemical composition was studied by Rutherford back scattering. • The density of sulfur vacancies and cadmium interstitial was varied

High-performance a-IGZO thin-film transistor with conductive indium-tin-oxide buried layer

Science.gov (United States)

Ahn, Min-Ju; Cho, Won-Ju

2017-10-01

In this study, we fabricated top-contact top-gate (TCTG) structure of amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs) with a thin buried conductive indium-tin oxide (ITO) layer. The electrical performance of a-IGZO TFTs was improved by inserting an ITO buried layer under the IGZO channel. Also, the effect of the buried layer's length on the electrical characteristics of a-IGZO TFTs was investigated. The electrical performance of the transistors improved with increasing the buried layer's length: a large on/off current ratio of 1.1×107, a high field-effect mobility of 35.6 cm2/Vs, a small subthreshold slope of 116.1 mV/dec, and a low interface trap density of 4.2×1011 cm-2eV-1 were obtained. The buried layer a-IGZO TFTs exhibited enhanced transistor performance and excellent stability against the gate bias stress.

Co-sputtered ZnO:Si thin films as transparent conductive oxides

Energy Technology Data Exchange (ETDEWEB)

Faure, C. [CNRS, Univ. Bordeaux, ICMCB, UPR 9048, F33600 Pessac (France); Clatot, J. [LRCS, 33 Rue St Leu, F-80039 Amiens (France); Teule-Gay, L.; Campet, G. [CNRS, Univ. Bordeaux, ICMCB, UPR 9048, F33600 Pessac (France); Labrugere, C. [CeCaMA, Universite de Bordeaux, ICMCB, 87 avenue du Dr. A. Schweitzer, Pessac, F-33608 (France); Nistor, M. [National Institute for Lasers, Plasmas and Radiation Physics, L22, PO Box MG-36, 77125 Bucharest-Magurele (Romania); Rougier, A., E-mail: rougier@icmcb-bordeaux.cnrs.fr [CNRS, Univ. Bordeaux, ICMCB, UPR 9048, F33600 Pessac (France)

2012-12-01

Silicon doped Zinc Oxide thin films, so-called SZO, were deposited at room temperature on glass and plastic substrates by co-sputtering of ZnO and SiO{sub 2} targets. The influence of the SiO{sub 2} target power supply (from 30 to 75 W) on the SZO thin film composition and crystallinity is discussed. Si/Zn atomic ratio, determined by X-ray microprobe, increases from 1.2 to 8.2 at.%. For Si/Zn ratio equal and lower than 3.9%, SZO (S{sub 3.9}ZO) thin films exhibit the Wurzite structure with the (0 0 2) preferred orientation. Larger Si content leads to a decrease in crystallinity. With Si addition, the resistivity decreases down to 3.5 Multiplication-Sign 10{sup -3} Ohm-Sign {center_dot}cm for SZO thin film containing 3.9 at.% of Si prior to an increase. The mean transmittance of S{sub 3.9}ZO thin film on glass substrate approaches 80% (it is about 90% for the film itself) in the visible range (from 400 to 750 nm). Co-sputtered SZO thin films are suitable candidates for large area transparent conductive oxides. - Highlights: Black-Right-Pointing-Pointer Si doped ZnO thin films by co-sputtering of ZnO and SiO{sub 2} targets. Black-Right-Pointing-Pointer Minimum of resistivity for Si doped ZnO thin films containing 3.9% of Si. Black-Right-Pointing-Pointer Si and O environments by X-ray Photoelectron Spectroscopy.

Effects of bacteria on CdS thin films used in technological devices

Science.gov (United States)

Alpdoğan, S.; Adıgüzel, A. O.; Sahan, B.; Tunçer, M.; Metin Gubur, H.

2017-04-01

Cadmium sulfide (CdS) thin films were fabricated on glass substrates by the chemical bath deposition method at 70 {}^\\circ \\text{C} considering deposition times ranging from 2 h to 5 h. The optical band gaps of CdS thin films were found to be in the 2.42-2.37 eV range. CdS thin films had uniform spherical nano-size grains which had polycrystalline, hexagonal and cubic phases. The films had a characteristic electrical resistivity of the order of {{10}5} Ω \\text{cm} and n-type conductivity at room condition. CdS thin films were incubated in cultures of B.domonas aeruginosa and Staphylococcus aureus, which exist abundantly in the environment, and form biofilms. SEM images showed that S. aureus and K. pneumonia were detected significantly on the film surfaces with a few of P. aeruginosa and B. subtilis cells attached. CdS thin film surface exhibits relatively good resistance to the colonization of P. aeruginosa and B. subtilis. Optical results showed that the band gap of CdS thin films which interacted with the bacteria is 2.42 \\text{eV} . The crystal structure and electrical properties of CdS thin films were not affected by bacterial adhesion. The antimicrobial effect of CdS nanoparticles was different for different bacterial strains.

KrF pulsed laser ablation of thin films made from fluorinated heterocyclic poly(naphthyl-imide)s.

Science.gov (United States)

Damaceanu, Mariana-Dana; Rusu, Radu-Dan; Olaru, Mihaela Adriana; Timpu, Daniel; Bruma, Maria

2012-06-01

Among the many aspects of laser ablation, development of conical structures induced by excimer laser radiation on polyimide surfaces has been thoroughly investigated. Because the mechanisms that produce these surface textures are not fully understood, two theories, photochemical bond breaking and thermal reaction, have been introduced. Here we present the first study of ultraviolet laser ablation behavior of thin films made from fluorinated poly(naphthyl-imide)s containing oxadiazole rings and the investigation of the mechanism of cone-like structure formation at two laser fluences, 57 and 240 mJ/cm(2). The morphology of thin films before and after laser ablation was studied by using various spectroscopy techniques such as Fourier transform infrared spectroscopy, time-resolved emission and X-ray photoelectron spectroscopy, atomic force microscopy, and contact angle measurements. All of the data suggest impurities shielded at low fluence radiation (57 mJ/cm(2)) and a radiation hardening process at high value fluence (240 mJ/cm(2)), which are proposed as the main mechanisms for laser ablation of our polyimide films, and we bring evidence to support them.

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.

High mobility single-crystalline-like GaAs thin films on inexpensive flexible metal substrates by metal-organic chemical vapor deposition

International Nuclear Information System (INIS)

Dutta, P.; Rathi, M.; Gao, Y.; Yao, Y.; Selvamanickam, V.; Zheng, N.; Ahrenkiel, P.; Martinez, J.

2014-01-01

We demonstrate heteroepitaxial growth of single-crystalline-like n and p-type doped GaAs thin films on inexpensive, flexible, and light-weight metal foils by metal-organic chemical vapor deposition. Single-crystalline-like Ge thin film on biaxially textured templates made by ion beam assisted deposition on metal foil served as the epitaxy enabling substrate for GaAs growth. The GaAs films exhibited strong (004) preferred orientation, sharp in-plane texture, low grain misorientation, strong photoluminescence, and a defect density of ∼10 7  cm −2 . Furthermore, the GaAs films exhibited hole and electron mobilities as high as 66 and 300 cm 2 /V-s, respectively. High mobility single-crystalline-like GaAs thin films on inexpensive metal substrates can pave the path for roll-to-roll manufacturing of flexible III-V solar cells for the mainstream photovoltaics market.

High mobility single-crystalline-like GaAs thin films on inexpensive flexible metal substrates by metal-organic chemical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Dutta, P., E-mail: pdutta2@central.uh.edu; Rathi, M.; Gao, Y.; Yao, Y.; Selvamanickam, V. [Department of Mechanical Engineering, University of Houston, Houston, Texas 77204 (United States); Zheng, N.; Ahrenkiel, P. [Department of Nanoscience and Nanoengineering, South Dakota School of Mines and Technology, Rapid City, South Dakota 57701 (United States); Martinez, J. [Materials Evaluation Laboratory, NASA Johnson Space Center, Houston, Texas 77085 (United States)

2014-09-01

We demonstrate heteroepitaxial growth of single-crystalline-like n and p-type doped GaAs thin films on inexpensive, flexible, and light-weight metal foils by metal-organic chemical vapor deposition. Single-crystalline-like Ge thin film on biaxially textured templates made by ion beam assisted deposition on metal foil served as the epitaxy enabling substrate for GaAs growth. The GaAs films exhibited strong (004) preferred orientation, sharp in-plane texture, low grain misorientation, strong photoluminescence, and a defect density of ∼10{sup 7 }cm{sup −2}. Furthermore, the GaAs films exhibited hole and electron mobilities as high as 66 and 300 cm{sup 2}/V-s, respectively. High mobility single-crystalline-like GaAs thin films on inexpensive metal substrates can pave the path for roll-to-roll manufacturing of flexible III-V solar cells for the mainstream photovoltaics market.

Double-layer indium doped zinc oxide for silicon thin-film solar cell prepared by ultrasonic spray pyrolysis

International Nuclear Information System (INIS)

Jiao Bao-Chen; Zhang Xiao-Dan; Wei Chang-Chun; Sun Jian; Ni Jian; Zhao Ying

2011-01-01

Indium doped zinc oxide (ZnO:In) thin films were prepared by ultrasonic spray pyrolysis on corning eagle 2000 glass substrate. 1 and 2 at.% indium doped single-layer ZnO:In thin films with different amounts of acetic acid added in the initial solution were fabricated. The 1 at.% indium doped single-layers have triangle grains. The 2 at.% indium doped single-layer with 0.18 acetic acid adding has the resistivity of 6.82×10 −3 Ω·cm and particle grains. The double-layers structure is designed to fabricate the ZnO:In thin film with low resistivity (2.58×10 −3 Ω·cm) and good surface morphology. It is found that the surface morphology of the double-layer ZnO:In film strongly depends on the substrate-layer, and the second-layer plays a large part in the resistivity of the double-layer ZnO:In thin film. Both total and direct transmittances of the double-layer ZnO:In film are above 80% in the visible light region. Single junction a-Si:H solar cell based on the double-layer ZnO:In as front electrode is also investigated. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Pulsed laser deposition of transparent conductive oxide thin films on flexible substrates

Science.gov (United States)

Socol, G.; Socol, M.; Stefan, N.; Axente, E.; Popescu-Pelin, G.; Craciun, D.; Duta, L.; Mihailescu, C. N.; Mihailescu, I. N.; Stanculescu, A.; Visan, D.; Sava, V.; Galca, A. C.; Luculescu, C. R.; Craciun, V.

2012-11-01

The influence of target-substrate distance during pulsed laser deposition of indium zinc oxide (IZO), indium tin oxide (ITO) and aluminium-doped zinc oxide (AZO) thin films grown on polyethylene terephthalate (PET) substrates was investigated. It was found that the properties of such flexible transparent conductive oxide (TCO)/PET electrodes critically depend on this parameter. The TCO films that were deposited at distances of 6 and 8 cm exhibited an optical transmittance higher than 90% in the visible range and electrical resistivities around 5 × 10-4 Ω cm. In addition to these excellent electrical and optical characteristics the films grown at 8 cm distance were homogenous, smooth, adherent, and without cracks or any other extended defects, being suitable for opto-electronic device applications.

Operation of a Five-Stage 40,000-CM2-Area Insulator Stack at 158 KV/CM

International Nuclear Information System (INIS)

Anderson RA; Clark, Robert E; Corcoran, PA; Douglas, John W; Gilliland, TL; Horry, ML; Hughes, Thomas P; Ives, HC; Long, FW; Martin, TH; McDaniel, DH; Milton, Osborne; Mostrom, Michael A; Seamen, JF; Shoup, RW; Smith, ID; Smith, JW; Spielman, RB; Struve, KW; Stygar, WA; Vogtlin, George E; Wagoner, TC; Yamamoto, Osamu

1999-01-01

We have demonstrated successful operation of a 3.35- m-diameter insulator stack at 158 kV/cm on five consecutive Z-accelerator shots. The stack consisted of five +45 deg;-profile 5.715-cm-thick cross-linked-polystyrene (Rexolite- 1422) insulator rings, and four anodized- aluminum grading rings shaped to reduce the field at cathode triple junctions. The width of the voltage pulse at 89% of peak was 32 ns. We compare this result to a new empirical flashover relation developed from previous small-insulator experiments conducted with flat unanodized electrodes. The relation predicts a 50% flashover probability for a Rexolite insulator during an applied voltage pulse when E max e -0.27/d (t eff C) 1/10 = 224, where E max is the peak mean electric field (kV/cm), d is the insulator thickness (cm), t eff is the effective pulse width (ps), and C is the insulator circumference (cm). We find the Z stack can be operated at a stress at least 19% higher than predicted. This result, and previous experiments conducted by Vogtlin, suggest anodized electrodes with geometries that reduce the field at both anode and cathode triple junctions would improve the flashover strength of +45 deg; insulators

Ultra-thin silicon/electro-optic polymer hybrid waveguide modulators

Energy Technology Data Exchange (ETDEWEB)

Qiu, Feng; Spring, Andrew M. [Institute for Materials Chemistry and Engineering, Kyushu University, 6-1 Kasuga-koen Kasuga, Fukuoka 816-8580 (Japan); Sato, Hiromu [Department of Molecular and Material Sciences, Kyushu University, 6-1 Kasuga-koen Kasuga, Fukuoka 816-8580 (Japan); Maeda, Daisuke; Ozawa, Masa-aki; Odoi, Keisuke [Nissan Chemical Industries, Ltd., 2-10-1 Tuboi Nishi, Funabashi, Chiba 274-8507 (Japan); Aoki, Isao; Otomo, Akira [National Institute of Information and Communications Technology, 588-2 Iwaoka, Nishi-ku, Kobe 651-2492 (Japan); Yokoyama, Shiyoshi, E-mail: s-yokoyama@cm.kyushu-u.ac.jp [Institute for Materials Chemistry and Engineering, Kyushu University, 6-1 Kasuga-koen Kasuga, Fukuoka 816-8580 (Japan); Department of Molecular and Material Sciences, Kyushu University, 6-1 Kasuga-koen Kasuga, Fukuoka 816-8580 (Japan)

2015-09-21

Ultra-thin silicon and electro-optic (EO) polymer hybrid waveguide modulators have been designed and fabricated. The waveguide consists of a silicon core with a thickness of 30 nm and a width of 2 μm. The cladding is an EO polymer. Optical mode calculation reveals that 55% of the optical field around the silicon extends into the EO polymer in the TE mode. A Mach-Zehnder interferometer (MZI) modulator was prepared using common coplanar electrodes. The measured half-wave voltage of the MZI with 7 μm spacing and 1.3 cm long electrodes is 4.6 V at 1550 nm. The evaluated EO coefficient is 70 pm/V, which is comparable to that of the bulk EO polymer film. Using ultra-thin silicon is beneficial in order to reduce the side-wall scattering loss, yielding a propagation loss of 4.0 dB/cm. We also investigated a mode converter which couples light from the hybrid EO waveguide into a strip silicon waveguide. The calculation indicates that the coupling loss between these two devices is small enough to exploit the potential fusion of a hybrid EO polymer modulator together with a silicon micro-photonics device.

Properties of Spray Pyrolysied Copper Oxide Thin Films

Directory of Open Access Journals (Sweden)

S. S. Roy

2017-02-01

Full Text Available Copper oxide (CuO thin films were deposited on well cleaned glass substrates by spray pyrolysis technique (SPT from cupric acetate (Cu(CH3COO2.H2O precursor solutions of 0.05 – 0.15 M molar concentrations (MC at a substrate temperature of 350 °C and at an air pressure of 1 bar. Effect of varying MC on the surface morphology, structural optical and electrical properties of CuO thin films were investigated. XRD patterns of the prepared films revealed the formation of CuO thin films having monoclinic structure with the main CuO (111 orientation and crystalline size ranging from 8.02 to 9.05 nm was observed. The optical transmission of the film was found to decrease with the increase of MC. The optical band gap of the thin films for 0.10 M was fond to be 1.60 eV. The room temperature electrical resistivity varies from 31 and 24 ohm.cm for the films grown with MC of 0.05 and 0.10 M respectively. The change in resistivity of the films was studied with respect to the change in temperature was shown that semiconductor nature is present. This information is expected to underlie the successful development of CuO films for solar windows and other semi-conductor applications including gas sensors.

Application of plasma silicon nitride to crystalline thin-film silicon solar cells. Paper

Energy Technology Data Exchange (ETDEWEB)

Schmidt, J.; Oberbeck, L.; Rinke, T.J.; Berge, C.; Bergmann, R.B.

2002-07-01

We use plasma-enhanced chemical vapour deposition to deposit silicon nitride (SiN{sub x}) films at low temperature(400 C) onto the front surface of two different types of crystalline thin-film Si solar cells. The silicon nitride acts as an excellent antireflection coating on Si and provides a very high degree of electronic surface passivation over a wide range of compositions, including near-stoichiometric and Si-rich SiN{sub x}. Application of stoichiometric SiN{sub x} to non-textured thin-film cells, epitaxially grown at low temperature by ion-assisted deposition onto a monocrystalline Si substrate, results in an open-circuit voltage of 622 mV, a short-circuit current density of 26.6 mA/cm{sup 2} and an efficiency of 12.7%. It is shown that the SiN{sub x}-passivated in-situ grown n{sup +}-emitter of this cell type allows to reach open-circuit voltages of up to 667 mV. Silicon-rich SiN{sub x} is applied to the phosphorus-diffused n{sup +}-emitter of a textured thin-film cell on a glass superstrate fabricated by layer-transfer. The emitter saturation current density of these cells is only 40-64 fA/cm{sup 2}, which allows for open-circuit voltages of up to 699 mV. An impressively high open-circuit voltage of 638 mV and a short-circuit current density of 32.0 mA/cm{sup 2} are obtained for a 25 {mu}m thick SiN{sub x}-passivated, random pyramid-textured transfer cell. A transfer cell efficiency of 15.3% is independently confirmed.

CuInS2 thin films obtained through the annealing of chemically deposited In2S3-CuS thin films

International Nuclear Information System (INIS)

Pena, Y.; Lugo, S.; Calixto-Rodriguez, M.; Vazquez, A.; Gomez, I.; Elizondo, P.

2011-01-01

In this work, we report the formation of CuInS 2 thin films on glass substrates by heating chemically deposited multilayers of copper sulfide (CuS) and indium sulfide (In 2 S 3 ) at 300 and 350 deg. C in nitrogen atmosphere at 10 Torr. CIS thin films were prepared by varying the CuS layer thickness in the multilayers with indium sulfide. The XRD analysis showed that the crystallographic structure of the CuInS 2 (JCPDS 27-0159) is present on the deposited films. From the optical analysis it was estimated the band gap value for the CIS film (1.49 eV). The electrical conductivity varies from 3 x 10 -8 to 3 Ω -1 cm -1 depending on the thickness of the CuS film. CIS films showed p-type conductivity.

Preparation and characterization of Cu2SnS3 thin films by electrodeposition

Science.gov (United States)

Patel, Biren; Narasimman, R.; Pati, Ranjan K.; Mukhopadhyay, Indrajit; Ray, Abhijit

2018-05-01

Cu2SnS3 thin films were electrodeposited on F:SnO2/Glass substrates at room temperature by using aqueous solution. Copper and tin were first electrodeposited from single bath and post annealed in the presence of sulphur atmosphere to obtain the Cu2SnS3 phase. The Cu2SnS3 phase with preferred orientation along the (112) crystal direction grows to greater extent by the post annealing of the film. Raman analysis confirms the monoclinic crystal structure of Cu2SnS3 with principle mode of vibration as A1 (symmetric breathing mode) corresponding to the band at 291 cm-1. It also reveals the benign coexistence of orthorhombic Cu3SnS4 and Cu2SnS7 phases. Optical properties of the film show direct band gap of 1.25 eV with a high absorption coefficient of the order of 104 cm-1 in the visible region. Photo activity of the electrodeposited film was established in two electrode photoelectro-chemical cell, where an open circuit voltage of 91.6 mV and a short circuit current density of 10.6 µA/cm2 were recorded. Fabrication of Cu2SnS3 thin film heterojunction solar cell is underway.

Structural phototransformation of WO{sub 3} thin films detected by photoacoustic analysis

Energy Technology Data Exchange (ETDEWEB)

Pacheco, Argelia Perez, E-mail: ekargy@hotmail.com [Universidad Nacional Autonoma de Mexico, Laboratorio de Fotofisica y Peliculas Delgadas-CCADET, Ciudad Universitaria, Coyoacan, A.P. 70-186, C.P. 04510, Mexico, D.F. (Mexico); Montes de Oca, C. Oliva; Castaneda-Guzman, R.; Garcia, A. Esparza [Universidad Nacional Autonoma de Mexico, Laboratorio de Fotofisica y Peliculas Delgadas-CCADET, Ciudad Universitaria, Coyoacan, A.P. 70-186, C.P. 04510, Mexico, D.F. (Mexico)

2012-11-15

Highlights: Black-Right-Pointing-Pointer The phototransformation of WO{sub 3} thin films were studied by photoacoustic technique. Black-Right-Pointing-Pointer The phase transition in WO{sub 3} thin films was induced by laser irradiation fluence. Black-Right-Pointing-Pointer The onset and end of the phototransformation in the thin films was identified. Black-Right-Pointing-Pointer The ablation threshold for each sample was identified. - Abstract: The photoacoustic technique (PA) was used to detect the phase transformation from amorphous to crystalline state of tungsten oxide (WO{sub 3}) thin films induced by UV pulsed laser radiation at low energy (<1.5 mJ). The evolution of photoacoustic signal was studied by a correlation analysis, comparing successive signals at fluences ranging from 0 to 20 mJ/cm{sup 2}. In this interval, it was possible to observe structural changes and the ablation threshold in films due to incident laser fluence effect. Thin films of WO{sub 3} were deposited by DC reactive magnetron sputtering over glass substrates at different deposition times. The results obtained by correlation analysis were compared with Raman spectroscopy data.

Deposition and characterization of spray pyrolysed p-type Cu2SnS3 thin film for potential absorber layer of solar cell

Science.gov (United States)

Thiruvenkadam, S.; Sakthi, P.; Prabhakaran, S.; Chakravarty, Sujay; Ganesan, V.; Rajesh, A. Leo

2018-06-01

Thin film of ternary Cu2SnS3 (CTS), a potential absorber layer for solar cells was successfully deposited by chemical spray pyrolysis technique. The GIXRD pattern revealed that the film having tetragonal Cu2SnS3 phase with the preferential orientation along (112), (200), (220) and (312) plane and it is further confirmed using Raman spectroscopy by the existence of Raman peak at 320 cm-1. Atomic Force Microscopy (AFM) was used to estimate the surface roughness of 28.8 nm. The absorption coefficient was found to be greater than the order of 105 cm-1 and bandgap of 1.70 eV. Hall effect measurement indicates the p type nature of the film with a hole concentration of 1.03 × 1016cm-3 and a hall mobility of 404 cm2/V. The properties of CTS thin film confirmed suitable to be a potential absorber layer material for photovoltaic applications.

In-situ study of pn-heterojunction interface states in organic thin film transistors

International Nuclear Information System (INIS)

Ye, Rongbin; Ohta, Koji; Baba, Mamoru

2014-01-01

In this paper, we have investigated the density of pn-heterojunction interface states by evaluating the threshold voltage shift with in-situ measurement of electrical characteristics of a sandwich fluorinated copper phthalocyanine/pentacene thin film transistor with various thicknesses of pentacene thin films. A threshold voltage (V T ) undergoes a significant shift from + 20.6 to + 0.53 V with increasing the thickness of pentacene. When the thickness of pentacene is more than a critical thickness of 15 nm, V T undergoes hardly any shift. On the other hand, the value of mobility is lightly decreased with increasing the thickness of pentacene due to the effect of the bulk current. Thus the V T shift is attributed to the increase of drain current in the sandwich device. In order to explain the V T shift, a model was assumed in the linear region of thin film transistor operation and the V T shift agrees with a tan −1 function of film thickness. The total charge density (Q 0 ) of 1.53 × 10 −7 C/cm 2 (9.56 × 10 11 electrons or holes/cm 2 ) was obtained. Furthermore, the V T shift and Q 0 could be adjusted by selecting a p-type semiconductor. - Highlights: • A threshold voltage was in-situ measured in an organic sandwich thin film transistor. • Density of pn-heterojunction interface states by evaluating the threshold voltage shift. • The threshold voltage shift attributes to the increase of drain current. • In order to explain the threshold voltage shift, a model was assumed

Electroresistance effect in gold thin film induced by ionic-liquid-gated electric double layer

International Nuclear Information System (INIS)

Nakayama, Hiroyasu; Ohtani, Takashi; Fujikawa, Yasunori; Ando, Kazuya; Saitoh, Eiji; Ye, Jianting; Iwasa, Yoshihiro

2012-01-01

Electroresistance effect was detected in a metallic thin film using ionic-liquid-gated electric-double-layer transistors (EDLTs). We observed reversible modulation of the electric resistance of a Au thin film. In this system, we found that an electric double layer works as a nanogap capacitor with 27 (-25) MV cm -1 of electric field by applying only 1.7 V of positive (negative) gate voltage. The experimental results indicate that the ionic-liquid-gated EDLT technique can be used for controlling the surface electronic states on metallic systems. (author)

Preparation of anatase TiO2 thin films by vacuum arc plasma evaporation

International Nuclear Information System (INIS)

Miyata, Toshihiro; Tsukada, Satoshi; Minami, Tadatsugu

2006-01-01

Anatase titanium dioxide (TiO 2 ) thin films with high photocatalytic activity have been prepared with deposition rates as high as 16 nm/min by a newly developed vacuum arc plasma evaporation (VAPE) method using sintered TiO 2 pellets as the source material. Highly transparent TiO 2 thin films prepared at substrate temperatures from room temperature to 400 deg. C exhibited photocatalytic activity, regardless whether oxygen (O 2 ) gas was introduced during the VAPE deposition. The highest photocatalytic activity and photo-induced hydrophilicity were obtained in anatase TiO 2 thin films prepared at 300 deg. C, which correlated to the best crystallinity of the films, as evidenced from X-ray diffraction. In addition, a transparent and conductive anatase TiO 2 thin film with a resistivity of 2.6 x 10 -1 Ω cm was prepared at a substrate temperature of 400 deg. C without the introduction of O 2 gas

Investigation of high- k yttrium copper titanate thin films as alternative gate dielectrics

International Nuclear Information System (INIS)

Monteduro, Anna Grazia; Ameer, Zoobia; Rizzato, Silvia; Martino, Maurizio; Caricato, Anna Paola; Maruccio, Giuseppe; Tasco, Vittorianna; Lekshmi, Indira Chaitanya; Hazarika, Abhijit; Choudhury, Debraj; Sarma, D D

2016-01-01

Nearly amorphous high- k yttrium copper titanate thin films deposited by laser ablation were investigated in both metal–oxide–semiconductor (MOS) and metal–insulator–metal (MIM) junctions in order to assess the potentialities of this material as a gate oxide. The trend of dielectric parameters with film deposition shows a wide tunability for the dielectric constant and AC conductivity, with a remarkably high dielectric constant value of up to 95 for the thick films and conductivity as low as 6  ×  10 −10 S cm −1 for the thin films deposited at high oxygen pressure. The AC conductivity analysis points out a decrease in the conductivity, indicating the formation of a blocking interface layer, probably due to partial oxidation of the thin films during cool-down in an oxygen atmosphere. Topography and surface potential characterizations highlight differences in the thin film microstructure as a function of the deposition conditions; these differences seem to affect their electrical properties. (paper)

Low operating voltage InGaZnO thin-film transistors based on Al{sub 2}O{sub 3} high-k dielectrics fabricated using pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Geng, G. Z.; Liu, G. X.; Zhang, Q.; Shan, F. K. [Qingdao University, Qingdao (China); DongEui University, Busan (Korea, Republic of); Lee, W. J.; Shin, B. C. [DongEui University, Busan (Korea, Republic of); Cho, C. R. [Pusan National University, Busan (Korea, Republic of)

2014-05-15

Low-voltage-driven amorphous indium-gallium-zinc-oxide (IGZO) thin-film transistors (TFTs) with an Al{sub 2}O{sub 3} dielectric were fabricated on a Si substrate by using pulsed laser deposition. Both Al{sub 2}O{sub 3} and IGZO thin films are amorphous, and the thin films have very smooth surfaces. The Al{sub 2}O{sub 3} gate dielectric exhibits a very low leakage current density of 1.3 x 10{sup -8} A/cm{sup 2} at 5 V and a high capacitance density of 60.9 nF/cm{sup 2}. The IGZO TFT with a structure of Ni/IGZO/Al{sub 2}O{sub 3}/Si exhibits high performance with a low threshold voltage of 1.18 V, a high field effect mobility of 20.25 cm{sup 2}V{sup -1}s{sup -1}, an ultra small subthreshold swing of 87 mV/decade, and a high on/off current ratio of 3 x 10{sup 7}.

Ferroelectric and piezoelectric properties of lead-free BaTiO{sub 3} doped Bi{sub 0.5}Na{sub 0.5}TiO{sub 3} thin films from metal-organic solution deposition

Energy Technology Data Exchange (ETDEWEB)

Acharya, Susant Kumar [Division of Advanced Materials Engineering, Hydrogen and Fuel Cell Research Center, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Department of Semiconductor Science and Technology, Basic Research Laboratory (BRL), Semiconductor Physics Research Center (SPRC), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Lee, Sang-Kwon; Hyung, Jung-Hwan [Department of Semiconductor Science and Technology, Basic Research Laboratory (BRL), Semiconductor Physics Research Center (SPRC), Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Yang, Yun-Ho; Kim, Bok-Hee [Division of Advanced Materials Engineering, Hydrogen and Fuel Cell Research Center, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Ahn, Byung-Guk, E-mail: bkahn@jbnu.ac.kr [Division of Advanced Materials Engineering, Hydrogen and Fuel Cell Research Center, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)

2012-11-05

Highlights: Black-Right-Pointing-Pointer Lead-free BNT-BT thin films from an optimized metal-organic solution deposition. Black-Right-Pointing-Pointer Phase and microstructure evolution with annealing temperature. Black-Right-Pointing-Pointer A relatively low leakage current density. Black-Right-Pointing-Pointer Good dielectric constant of 613 at a frequency of 1 kHz. Black-Right-Pointing-Pointer High remanent polarization and piezoelectric constant comparable to PZT thin films. - Abstract: Lead-free 0.94Bi{sub 0.5}Na{sub 0.5}TiO{sub 3}-0.06BaTiO{sub 3} (BNT-BT) piezoelectric thin films were prepared by metal-organic solution deposition onto a Pt/Ti/SiO{sub 2}/Si substrate. A dense and well crystallized thin film with a perovskite phase was obtained by annealing these films at 700 Degree-Sign C. Atomic force microscopy showed that these films were smooth and crack-free with an average grain size on the order of 200 nm. Thin films of 356 nm thickness exhibited a small signal dielectric constant and a loss tangent at 1 kHz of 613 and 0.044, respectively. Ferroelectric hysteresis measurements indicated a remanent polarization value of 21.5 {mu}C/cm{sup 2} with a coercive field of 164.5 kV/cm. The leakage current density of the thin film was 4.08 Multiplication-Sign 10{sup -4} A/cm{sup 2} at an applied electric field of 200 kV/cm. A typical butterfly-shaped piezoresponse loop was observed and the effective piezoelectric coefficient (d{sub 33}) of the BNT-BT thin film was approximately 51.6 pm/V.

Radiation hardness and charge collection efficiency of lithium irradiated thin silicon diodes

CERN Document Server

Boscardin, Maurizio; Bruzzi, Mara; Candelori, Andrea; Focardi, Ettore; Khomenkov, Volodymyr P; Piemonte, Claudio; Ronchin, S; Tosi, C; Zorzi, N

2005-01-01

Due to their low depletion voltage, even after high particle fluences, improved tracking precision and momentum resolution, and reduced material budget, thin substrates are one of the possible choices to provide radiation hard detectors for future high energy physics experiments. In the framework of the CERN RD50 Collaboration, we have developed PIN diode detectors on membranes obtained by locally thinning the silicon substrate by means of TMAH etching from the wafer backside. Diodes of different shapes and sizes have been fabricated on 50- mu m and 100- mu m thick membranes and tested, showing a low leakage current (of 300 nA/cm/sup 3/) and a very low depletion voltage (in the order of 1 V for the 50 mu m membrane) before irradiation. Radiation damage tests have been performed with 58 MeV lithium (Li) ions up to the fluence of 10/sup 14/ Li/cm/sup 2/ in order to determine the depletion voltage and leakage current density increase after irradiation. Charge collection efficiency tests carried out with a beta /...

Traumatic Experiences, Stressful Events, and Alexithymia in Chronic Migraine With Medication Overuse

Directory of Open Access Journals (Sweden)

Sara Bottiroli

2018-05-01

Full Text Available Background: Many factors are involved in the prognosis and outcome of Chronic Migraine and Medication Overuse Headache (CM+MOH, and their understanding is a topic of interest. It is well known that CM+MOH patients experience increased psychiatric comorbidity, such as anxiety, depression, or personality disorders. Other psychological factors still need to be explored. The present study is aimed to evaluate whether early life traumatic experiences, stressful life events, and alexithymia can be associated with CM+MOH.Methods: Three hundred and thirty-one individuals were recruited for this study. They belonged to one of the two following groups: CM+MOH (N = 179; 79% females, Age: 45.2 ± 9.8 and episodic migraine (EM (N = 152; 81% females; Age: 40.7 ± 11.0. Diagnosis was operationally defined according to the International Classification of Headache Disorders 3rd edition (ICHD-IIIβ. Data on early life (physical and emotional traumatic experiences, recent stressful events and alexithymia were collected by means of the Childhood Trauma Questionnaire, the Stressful life-events Questionnaire, and the Toronto Alexithymia Scale (TAS-20, respectively.Results: Data showed a higher prevalence of emotional (χ2 = 6.99; d.f. = 1; p = 0.006 and physical (χ2 = 6.18; d.f. = 1; p = 0.009 childhood trauma and of current stressful events of important impact (χ2 = 4.42; d.f. = 1; p = 0.025 in CM+MOH patients than in EM ones. CM+MOH patients were characterized by higher difficulties in a specific alexithymic trait (Factor 1 subscale of TAS-20 [F(1, 326 = 6.76, p = 0.01, ηp2 = 0.02] when compared to the EM group. The role of these factors was confirmed in a multivariate analysis, which showed an association of CM+MOH with emotional (OR 2.655; 95% CI 1.153–6.115, p = 0.022 or physical trauma (OR 2.763; 95% CI 1.322–5.771, p = 0.007, and a high score at the Factor 1 (OR 1.039; 95% CI 1.002–1.078, p = 0.040.Conclusions: Our findings demonstrated a clear

Effects of mixture and thinning in a tree farming valuable broadleaves plantation more than 20 years after the establishment.

Directory of Open Access Journals (Sweden)

Alessio Corazzesi

2010-12-01

Full Text Available The results of peduncolate Oak plantation trials where the Oak is mixed to wild Cherry and narrow-leaf Ash per line and per close mixture with different proportions (25% and 50% of N-fixing species (Black Locust and Italian Alder are described in the paper. The plantation, carried out in winter 1988-89, was framed into a reafforestation plan for spoil banks restoration. On a share of the plantation area, free thinnings foreseeing the release of about 70 target trees per hectare, were undertaken in 2001 and 2003; 21% and 27% of basal area were removed, respectively. In the latter trial, the crowns of target trees were completely isolated by felling all the surrounding trees. The performances of valuable timber broadleaves, the effects of intercropping and thinning on the growth of Oak target trees were analysed. Three inventories (2001, 2004 and 2008 and the annual monitoring of target trees growth were performed at the purpose. The two peduncolate Oak and narrow-leaf Ash trees showed the best performances among the set of valuable broadleaves, whilst wild cherry resulted not suited to local site conditions. A higher tree mortality occurred in the mixture with Black Locust. The mixture with both Nfixing species provided a stimulus to the Oak growth both in terms of dbh and tree height. Italian Alder resulted anyway less competitive and easy to manage, considering its progressive self-thinning, while Black Locust was aggressive enough to necessitate the control of its development by pollarding 7 years after the plantation. In the thinned plots, target trees showed significant diameter increments in comparison with control plots; maintaining year by year constant dbh increments of about 1 cm and crown’s diameter increment of about 50 cm. Intercropping with Italian Alder showed to be more effective than thinning on growth of the target trees. st1\\:*{behavior:url(#ieooui } /* Style Definitions */ table.MsoNormalTable {mso

Textured indium tin oxide thin films by chemical solution deposition and rapid thermal processing

International Nuclear Information System (INIS)

Mottern, Matthew L.; Tyholdt, Frode; Ulyashin, Alexander; Helvoort, Antonius T.J. van; Verweij, Henk; Bredesen, Rune

2007-01-01

The microstructure of state-of-the-art chemical solution deposited indium tin oxide thin films typically consists of small randomly oriented grains, high porosity and poor homogeneity. The present study demonstrates how the thin film microstructure can be improved significantly by tailoring the precursor solutions and deposition conditions to be kinetically and thermodynamically favorable for generation of homogeneous textured thin films. This is explained by the occurrence of a single heterogeneous nucleation mechanism. The as-deposited thin films, crystallized at 800 deg. C, have a high apparent density, based on a refractive index of ∼ 1.98 determined by single wavelength ellipsometry at 633 nm. The microstructure of the films consists of columnar grains with preferred orientation as determined by X-ray diffraction and transmission electron microscopy. The resistivity, measured by the four point probe method, is ∼ 2 x 10 -3 Ω cm prior to post-deposition treatments

Component-Based Data-Driven Predictive Maintenance to Reduce Unscheduled Maintenance Events

NARCIS (Netherlands)

Verhagen, W.J.C.; Curran, R.; de Boer, L.W.M.; Chen, C.H.; Trappey, A.C.; Peruzzini, M.; Stjepandić, J.; Wognum, N.

2017-01-01

cm 0cm 10pt;">Costs associated with unscheduled and preventive maintenance can contribute significantly to an airline's expenditure. Reliability analysis can help to identify and plan for maintenance events. Reliability analysis in industry is often limited to statistically based

Conduction properties of thin films from a water soluble carbon nanotube/hemicellulose complex

Science.gov (United States)

Shao, Dongkai; Yotprayoonsak, Peerapong; Saunajoki, Ville; Ahlskog, Markus; Virtanen, Jorma; Kangas, Veijo; Volodin, Alexander; Van Haesendonck, Chris; Burdanova, Maria; Mosley, Connor D. W.; Lloyd-Hughes, James

2018-04-01

We have examined the conductive properties of carbon nanotube based thin films, which were prepared via dispersion in water by non-covalent functionalization of the nanotubes with xylan, a type of hemicellulose. Measurements of low temperature conductivity, Kelvin probe force microscopy, and high frequency (THz) conductivity elucidated the intra-tube and inter-tube charge transport processes in this material. The measurements show excellent conductive properties of the as prepared thin films, with bulk conductivity up to 2000 S cm-1. The transport results demonstrate that the hemicellulose does not seriously interfere with the inter-tube conductance.

Martensitic phase transformations and magnetocaloric effect in Al co-sputtered Ni–Mn–Sb alloy thin films

International Nuclear Information System (INIS)

Akkera, Harish Sharma; Choudhary, Nitin; Kaur, Davinder

2015-01-01

Highlights: • The Al content leads to a increase in the martensitic transformation temperature. • A maximum ΔS M = 23 mJ/cm 3 K at 300 K was observed in the N 49.8 Mn 32.97 Al 4.43 Sb 12.8 . • The refrigeration capacity RC = 64.4 mJ/cm 3 at 2 T for N 49.8 Mn 32.97 Al 4.43 Sb 12.8 film. - Abstract: We systematically investigated the influence of aluminium (Al) content on the martensitic transformations and magnetocaloric effect (MCE) in Ni–Mn–Sb ferromagnetic shape memory alloy (FSMA) thin films. The temperature-dependent magnetization (M–T) and resistance (R–T) results displayed a monotonic increase in martensitic transformation temperature (T M ) with increasing Al content. From the isothermal magnetization (M–H) curves, a large magnetic entropy change (ΔS M ) of 23 mJ/cm 3 K was observed in N 49.8 Mn 32.97 Al 4.43 Sb 12.8 . A remarkable enhancement of MCE could be attributed to the significant change in the magnetization of Ni–Mn–Sb films with increasing Al content. Furthermore, a high refrigerant capacity (RC) was observed in Ni–Mn–Sb–Al thin films as compared to pure Ni–Mn–Sb. The substitution of Al for Mn in Ni–Mn–Sb thin films with field induced MCE are potential candidates for micro length scale magnetic refrigeration applications where low magnetic fields are desirable

A long record of extreme wave events in coastal Lake Hamana, Japan

Science.gov (United States)

Boes, Evelien; Yokoyama, Yusuke; Schmidt, Sabine; Riedesel, Svenja; Fujiwara, Osamu; Nakamura, Atsunori; Garrett, Ed; Heyvaert, Vanessa; Brückner, Helmut; De Batist, Marc

2017-04-01

different types of sand units: i) massive to layered sands with a sharp, erosive lower contact, ii) thin, discontinuous sand lenses with a sharp lower contact and iii) inter-fingered sand-rich and silt-rich intervals with a gradual lower contact. Variability in appearance suggests a variety in triggering events too, going from tsunamis, over storm surges (typhoons) to the impact of sea-level changes on the interaction between tidal delta and lacustrine sedimentation. Preliminary dating (210Pb/137Cs) results in sedimentation rates of 0.4 cm/yr for the last 100-150 yr. Two closely-spaced tephra layers are tentatively linked with the reported Osawa Fuji scoria (3090 BP) and Kawago-daira pumice (3150 BP). However, more absolute ages (14C and OSL) are essential in order to obtain an accurate age-depth model and to position events in time. We are proceeding with the age determination of event sand beds based on single-grain OSL dating of feldspars. Whereas quartz appeared to be not suitable for dating, research in onshore archives close to Lake Hamana already proved the suitability of the IRSL50 signal of feldspar.

Chemical solution deposition of YBCO thin film by different polymer additives

International Nuclear Information System (INIS)

Wang, W.T.; Li, G.; Pu, M.H.; Sun, R.P.; Zhou, H.M.; Zhang, Y.; Zhang, H.; Yang, Y.; Cheng, C.H.; Zhao, Y.

2008-01-01

A polymer-assisted chemical solution deposition approach has been proposed for the preparation of YBCO thin film. Different additives like PVB (polyvinyl butyral), PEG (polyethylene glycol) and PVP (polyvinylpyrrolidone) have been used to adjust the final viscosity of the precursor solution and thus the film formation. In this fluorine-free approach, YBCO has been deposited on single crystal substrates with metal acetates being starting materials. Biaxially textured YBCO thin films have been obtained. However, different additives lead to different microstructure. Dense, smooth and crack-free YBCO film prepared with PVB as additive yields sharp superconducting transition around T c = 90 K as well as high J c (0 T, 77 K) over 3 MA/cm 2

Chemical solution deposition of YBCO thin film by different polymer additives

Energy Technology Data Exchange (ETDEWEB)

Wang, W.T.; Li, G.; Pu, M.H.; Sun, R.P.; Zhou, H.M.; Zhang, Y. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); Zhang, H. [Department of Physics, Peking University, Beijing 100871 (China); Yang, Y. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); Cheng, C.H. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); School of Materials Science and Engineering, University of New South Wale, Sydney, 2052 NSW (Australia); Zhao, Y. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); School of Materials Science and Engineering, University of New South Wale, Sydney, 2052 NSW (Australia)], E-mail: yzhao@swjtu.edu.cn

2008-09-15

A polymer-assisted chemical solution deposition approach has been proposed for the preparation of YBCO thin film. Different additives like PVB (polyvinyl butyral), PEG (polyethylene glycol) and PVP (polyvinylpyrrolidone) have been used to adjust the final viscosity of the precursor solution and thus the film formation. In this fluorine-free approach, YBCO has been deposited on single crystal substrates with metal acetates being starting materials. Biaxially textured YBCO thin films have been obtained. However, different additives lead to different microstructure. Dense, smooth and crack-free YBCO film prepared with PVB as additive yields sharp superconducting transition around T{sub c} = 90 K as well as high J{sub c} (0 T, 77 K) over 3 MA/cm{sup 2}.

Leveraging the NLM map from SNOMED CT to ICD-10-CM to facilitate adoption of ICD-10-CM.

Science.gov (United States)

Cartagena, F Phil; Schaeffer, Molly; Rifai, Dorothy; Doroshenko, Victoria; Goldberg, Howard S

2015-05-01

Develop and test web services to retrieve and identify the most precise ICD-10-CM code(s) for a given clinical encounter. Facilitate creation of user interfaces that 1) provide an initial shortlist of candidate codes, ideally visible on a single screen; and 2) enable code refinement. To satisfy our high-level use cases, the analysis and design process involved reviewing available maps and crosswalks, designing the rule adjudication framework, determining necessary metadata, retrieving related codes, and iteratively improving the code refinement algorithm. The Partners ICD-10-CM Search and Mapping Services (PI-10 Services) are SOAP web services written using Microsoft's.NET 4.0 Framework, Windows Communications Framework, and SQL Server 2012. The services cover 96% of the Partners problem list subset of SNOMED CT codes that map to ICD-10-CM codes and can return up to 76% of the 69,823 billable ICD-10-CM codes prior to creation of custom mapping rules. We consider ways to increase 1) the coverage ratio of the Partners problem list subset of SNOMED CT codes and 2) the upper bound of returnable ICD-10-CM codes by creating custom mapping rules. Future work will investigate the utility of the transitive closure of SNOMED CT codes and other methods to assist in custom rule creation and, ultimately, to provide more complete coverage of ICD-10-CM codes. ICD-10-CM will be easier for clinicians to manage if applications display short lists of candidate codes from which clinicians can subsequently select a code for further refinement. The PI-10 Services support ICD-10 migration by implementing this paradigm and enabling users to consistently and accurately find the best ICD-10-CM code(s) without translation from ICD-9-CM. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Fabrication of {sup 94}Zr thin target for recoil distance doppler shift method of lifetime measurement

Energy Technology Data Exchange (ETDEWEB)

Gupta, C.K.; Rohilla, Aman [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Abhilash, S.R.; Kabiraj, D.; Singh, R.P. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Mehta, D. [Department of Physics, Panjab University, Chandigarh 160014 (India); Chamoli, S.K., E-mail: skchamoli@physics.du.ac.in [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India)

2014-11-11

A thin isotopic {sup 94}Zr target of thickness 520μg/cm{sup 2} has been prepared for recoil distance Doppler shift method (RDM) lifetime measurement by using an electron beam deposition method on tantalum backing of 3.5 mg/cm{sup 2} thickness at Inter University Accelerator Center (IUAC), New Delhi. To meet the special requirement of smoothness of surface for RDM lifetime measurement and also to protect the outer layer of {sup 94}Zr from peeling off, a very thin layer of gold has been evaporated on a {sup 94}Zr target on a specially designed substrate holder. In all, 143 mg of 99.6% enriched {sup 94}Zr target material was utilized for the fabrication of {sup 94}Zr targets. The target has been successfully used in a recent RDM lifetime measurement experiment at IUAC.

Ecofriendly and Nonvacuum Electrostatic Spray-Assisted Vapor Deposition of Cu(In,Ga)(S,Se)2 Thin Film Solar Cells.

Science.gov (United States)

Hossain, Md Anower; Wang, Mingqing; Choy, Kwang-Leong

2015-10-14

Chalcopyrite Cu(In,Ga)(S,Se)2 (CIGSSe) thin films have been deposited by a novel, nonvacuum, and cost-effective electrostatic spray-assisted vapor deposition (ESAVD) method. The generation of a fine aerosol of precursor solution, and their controlled deposition onto a molybdenum substrate, results in adherent, dense, and uniform Cu(In,Ga)S2 (CIGS) films. This is an essential tool to keep the interfacial area of thin film solar cells to a minimum value for efficient charge separation as it helps to achieve the desired surface smoothness uniformity for subsequent cadmium sulfide and window layer deposition. This nonvacuum aerosol based approach for making the CIGSSe film uses environmentally benign precursor solution, and it is cheaper for producing solar cells than that of the vacuum-based thin film solar technology. An optimized CIGSSe thin film solar cell with a device configuration of molybdenum-coated soda-lime glass substrate/CIGSSe/CdS/i-ZnO/AZO shows the photovoltaic (j-V) characteristics of Voc=0.518 V, jsc=28.79 mA cm(-2), fill factor=64.02%, and a promising power conversion efficiency of η=9.55% under simulated AM 1.5 100 mW cm(-2) illuminations, without the use of an antireflection layer. This demonstrates the potential of ESAVD deposition as a promising alternative approach for making thin film CIGSSe solar cells at a lower cost.

High rate deposition of transparent conducting oxide thin films by vacuum arc plasma evaporation

International Nuclear Information System (INIS)

Minami, Tadatsugu; Ida, Satoshi; Miyata, Toshihiro

2002-01-01

Transparent conducting oxide (TCO) thin films have been deposited at a high rate above 370 nm/min by vacuum arc plasma evaporation (VAPE) using sintered oxide fragments as the source material. It was found that the deposition rate of TCO films was strongly dependent on the deposition pressure, whereas the obtained electrical properties were relatively independent of the pressure. Resistivities of 5.6x10 -4 and 2.3x10 -4 Ω·cm and an average transmittance above 80% (with substrate included) in the visible range were obtained in Ga-doped ZnO (GZO) thin films deposited at 100 and 350 deg. C, respectively. In addition, a resistivity as low as 1.4x10 -4 Ω·cm and an average transmittance above 80% were also obtained in indium-tin-oxide (ITO) films deposited at 300 deg. C. The deposited TCO films exhibited uniform distributions of resistivity and thickness on large area substrates

High rate deposition of transparent conducting oxide thin films by vacuum arc plasma evaporation

Energy Technology Data Exchange (ETDEWEB)

Minami, Tadatsugu; Ida, Satoshi; Miyata, Toshihiro

2002-09-02

Transparent conducting oxide (TCO) thin films have been deposited at a high rate above 370 nm/min by vacuum arc plasma evaporation (VAPE) using sintered oxide fragments as the source material. It was found that the deposition rate of TCO films was strongly dependent on the deposition pressure, whereas the obtained electrical properties were relatively independent of the pressure. Resistivities of 5.6x10{sup -4} and 2.3x10{sup -4} {omega}{center_dot}cm and an average transmittance above 80% (with substrate included) in the visible range were obtained in Ga-doped ZnO (GZO) thin films deposited at 100 and 350 deg. C, respectively. In addition, a resistivity as low as 1.4x10{sup -4} {omega}{center_dot}cm and an average transmittance above 80% were also obtained in indium-tin-oxide (ITO) films deposited at 300 deg. C. The deposited TCO films exhibited uniform distributions of resistivity and thickness on large area substrates.

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.

TiFeCoNi oxide thin film - A new composition with extremely low electrical resistivity at room temperature

International Nuclear Information System (INIS)

Yang, Ya-Chu; Tsau, Chun-Huei; Yeh, Jien-Wei

2011-01-01

We show the electrical resistivity of a TiFeCoNi oxide thin film. The electrical resistivity of the TiFeCoNi thin film decreased sharply after a suitable period of oxidation at high temperature. The lowest resistivity of the TiFeCoNi oxide film was 35 ± 3 μΩ-cm. The low electrical resistivity of the TiFeCoNi oxide thin film was attributed to Ti, which is more reactive than the other elements, reacting with oxygen at the initial stage of annealing. The low resistivity is caused by the remaining electrons.

Laser damage properties of TiO2/Al2O3 thin films grown by atomic layer deposition

International Nuclear Information System (INIS)

Wei Yaowei; Liu Hao; Sheng Ouyang; Liu Zhichao; Chen Songlin; Yang Liming

2011-01-01

Research on thin film deposited by atomic layer deposition (ALD) for laser damage resistance is rare. In this paper, it has been used to deposit TiO 2 /Al 2 O 3 films at 110 deg. C and 280 deg. C on fused silica and BK7 substrates. Microstructure of the thin films was investigated by x-ray diffraction. The laser-induced damage threshold (LIDT) of samples was measured by a damage test system. Damage morphology was studied under a Nomarski differential interference contrast microscope and further checked under an atomic force microscope. Multilayers deposited at different temperatures were compared. The results show that the films deposited by ALD had better uniformity and transmission; in this paper, the uniformity is better than 99% over 100 mm Φ samples, and the transmission is more than 99.8% at 1064 nm. Deposition temperature affects the deposition rate and the thin film microstructure and further influences the LIDT of the thin films. As to the TiO 2 /Al 2 O 3 films, the LIDTs were 6.73±0.47 J/cm 2 and 6.5±0.46 J/cm 2 at 110 deg. C on fused silica and BK7 substrates, respectively. The LIDTs at 110 deg. C are notably better than 280 deg. C.

Temperature responsive functional polymeric thin films obtained by matrix assisted pulsed laser evaporation for cells attachment–detachment study

Energy Technology Data Exchange (ETDEWEB)

Rusen, L. [NILPRP, National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Street, PO Box MG-16, RO-077125 Magurele, Bucharest (Romania); Dinca, V., E-mail: dinali@nipne.ro [NILPRP, National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Street, PO Box MG-16, RO-077125 Magurele, Bucharest (Romania); Mitu, B. [NILPRP, National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Street, PO Box MG-16, RO-077125 Magurele, Bucharest (Romania); Mustaciosu, C. [Horia Hulubei National Institute of Physics and Nuclear Engineering, IFIN HH, Magurele, Bucharest (Romania); Dinescu, M. [NILPRP, National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Street, PO Box MG-16, RO-077125 Magurele, Bucharest (Romania)

2014-05-01

Multifunctional thin films used as thermoresponsive substrate for engineering cell sheets represent an important area in tissue engineering. As the morphology and the chemical characteristics of the thin films directly control their interaction with cells, it is important to correlate these characteristics with the biological answer. In this study, thermally sensitive poly(N-isopropylacrylamide), (pNIPAAm) thin films were prepared by matrix assisted pulsed laser evaporation and utilized in L929 cell adhesion and detachment studies. Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM) were used to determine the pNIPAAm thin films chemical and morphological characteristics. The FTIR data demonstrated that the functional groups in the MAPLE-deposited films remained intact for fluences in the range of 200–600 mJ cm{sup −2}. Within this fluence range, the AFM topographical studies showed that the roughness of the coatings was dependent on laser fluence and the obtained surfaces were characterized by a granular aspect. L929 cell viability studies onto the pNIPAAm coatings showed little or no toxic effect for fluences below 600 mJ cm{sup −2}, while for higher fluences, viability was decreased with more than 50%. The adhesion and detachment of the cell was found to be mainly dependent on the film surface morphology.

Structural and optical properties of DC reactive magnetron sputtered zinc aluminum oxide thin films

Energy Technology Data Exchange (ETDEWEB)

Kumar, B. Rajesh, E-mail: rajphyind@gmail.com [Department of Physics, GITAM Institute of Technology, GITAM University, Visakhapatnam - 530 045, A.P. (India); Rao, T. Subba, E-mail: thotasubbarao6@gmail.com [Department of Physics, Sri Krishnadevaraya University, Anantapuramu - 515 003, A.P. (India)

2014-10-15

Highly transparent conductive Zinc Aluminum Oxide (ZAO) thin films have been deposited on glass substrates using DC reactive magnetron sputtering method. The thin films were deposited at 200 °C and post-deposition annealing from 15 to 90 min. XRD patterns of ZAO films exhibit only (0 0 2) diffraction peak, indicating that they have c-axis preferred orientation perpendicular to the substrate. Scanning electron microscopy (SEM) is used to study the surface morphology of the films. The grain size obtained from SEM images of ZAO thin films are found to be in the range of 20 - 26 nm. The minimum resistivity of 1.74 × 10{sup −4} Ω cm and an average transmittance of 92% are obtained for the thin film post annealed for 30 min. The optical band gap of ZAO thin films increased from 3.49 to 3.60 eV with the increase of annealing time due to Burstein-Moss effect. The optical constants refractive index (n) and extinction coefficient (k) were also determined from the optical transmission spectra.

Thin Film Microbatteries

International Nuclear Information System (INIS)

Dudney, Nancy J.

2008-01-01

Thin film batteries are built layer by layer by vapor deposition. The resulting battery is formed of parallel plates, much as an ordinary battery construction, just much thinner. The figure (Fig. 1) shows an example of a thin film battery layout where films are deposited symmetrically onto both sides of a supporting substrate. The full stack of films is only 10 to 15 (micro)m thick, but including the support at least doubles the overall battery thickness. When the support is thin, the entire battery can be flexible. At least six companies have commercialized or are very close to commercializing such all-solid-state thin film batteries and market research predicts a growing market and a variety of applications including sensors, RFID tags, and smarter cards. In principle with a large deposition system, a thin film battery might cover a square meter, but in practice, most development is targeting individual cells with active areas less than 25 cm 2 . For very small battery areas, 2 , microfabrication processes have been developed. Typically the assembled batteries have capacities from 0.1 to 5 mAh. The operation of a thin film battery is depicted in the schematic diagram (Fig. 2). Very simply, when the battery is allowed to discharge, a Li + ion migrates from the anode to the cathode film by diffusing through the solid electrolyte. When the anode and cathode reactions are reversible, as for an intercalation compound or alloy, the battery can be recharged by reversing the current. The difference in the electrochemical potential of the lithium determines the cell voltage. Most of the thin films used in current commercial variations of this thin film battery are deposited in vacuum chambers by RF and DC magnetron sputtering and by thermal evaporation onto unheated substrates. In addition, many publications report exploring a variety of other physical and chemical vapor deposition processes, such as pulsed laser deposition, electron cyclotron resonance sputtering, and

Effect of acetic acid on wet patterning of copper/molybdenum thin films in phosphoric acid solution

International Nuclear Information System (INIS)

Seo, Bo.-Hyun; Lee, Sang-Hyuk; Park, In-Sun; Seo, Jong Hyun; Choe, HeeHwan; Jeon, Jae-Hong; Hong, Munpyo; Lee, Yong Uk; Winkler, Joerg

2011-01-01

Copper metallization is a key issue for high performance thin film transistor (TFT) technology. A phosphoric acid based copper etchant is a potentially attractive alternative to the conventional hydrogen peroxide based etchant due to its longer-life expectancy time and higher stability in use. In this paper, it is shown that amount of the acetic acid in the phosphoric based copper etchant plays an important role in controlling the galvanic reaction between the copper and the molybdenum. As the concentration of acetic acid in the phosphoric mixture solution increased from 0 M to 0.4 M, the measured galvanic current density dropped from 32 mA/cm 2 to 26 mA/cm 2 , indicating that the acetic acid induces the lower galvanic reaction between the copper and the molybdenum in the solution. From the XPS analysis, with the addition of the acetic acid, the thickness of the protective MoO 2 passive film covering the molybdenum surface grew and the dissolution rate of the molybdenum thin film decreased. However, the dissolution rate of the copper thin film increased as the concentration of acetic acid in the mixture solution increased.

Effect of acetic acid on wet patterning of copper/molybdenum thin films in phosphoric acid solution

Energy Technology Data Exchange (ETDEWEB)

Seo, Bo.-Hyun; Lee, Sang-Hyuk; Park, In-Sun [Department of Materials Engineering, Korea Aerospace University, Hwajeon, Goyang, Gyonggi-do 412-791 (Korea, Republic of); Seo, Jong Hyun, E-mail: jhseo@kau.ac.kr [Department of Materials Engineering, Korea Aerospace University, Hwajeon, Goyang, Gyonggi-do 412-791 (Korea, Republic of); Choe, HeeHwan; Jeon, Jae-Hong [School of Electronics, Telecommunications and Computer Engineering, Korea Aerospace University, Hwajeon, Goyang, Gyonggi-do 412-791 (Korea, Republic of); Hong, Munpyo [Display and Semiconductor Physics, Korea University (Korea, Republic of); Lee, Yong Uk [PETEC (The Printable Electronics Technology Centre) (United Kingdom); Winkler, Joerg [PLANSEE Metal GmbH, Metallwerk-Plansee-Str. 71A-6600, Reutte (Austria)

2011-08-01

Copper metallization is a key issue for high performance thin film transistor (TFT) technology. A phosphoric acid based copper etchant is a potentially attractive alternative to the conventional hydrogen peroxide based etchant due to its longer-life expectancy time and higher stability in use. In this paper, it is shown that amount of the acetic acid in the phosphoric based copper etchant plays an important role in controlling the galvanic reaction between the copper and the molybdenum. As the concentration of acetic acid in the phosphoric mixture solution increased from 0 M to 0.4 M, the measured galvanic current density dropped from 32 mA/cm{sup 2} to 26 mA/cm{sup 2}, indicating that the acetic acid induces the lower galvanic reaction between the copper and the molybdenum in the solution. From the XPS analysis, with the addition of the acetic acid, the thickness of the protective MoO{sub 2} passive film covering the molybdenum surface grew and the dissolution rate of the molybdenum thin film decreased. However, the dissolution rate of the copper thin film increased as the concentration of acetic acid in the mixture solution increased.

Photoelectrochemical properties of In{sub 2}Se{sub 3} thin films: Effect of substrate temperature

Energy Technology Data Exchange (ETDEWEB)

Yadav, Abhijit A., E-mail: aay_physics@yahoo.co.in [Thin Film Physics Laboratory, Department of Physics, Electronics and Photonics, Rajarshi Shahu Mahavidyalaya, Latur, M.S. 413512 (India); Salunke, S.D. [Department of Chemistry and Analytical Chemistry, Rajarshi Shahu Mahavidyalaya, Latur, M.S. 413512 (India)

2015-08-15

Highlights: • Photoelectrochemical properties of In{sub 2}Se{sub 3} thin films. • In{sub 2}Se{sub 3} films are of n-type with I{sub sc} and V{sub oc} of 1.05 mA/cm{sup 2} and 261 mV respectively. • Efficiency (η) and fill factor (FF) is found to be 0.71% and 0.51% respectively. • Performance of cell can motivate further studies concerning solar energy conversion. - Abstract: In{sub 2}Se{sub 3} thin films have been deposited onto fluorine doped tin oxide coated (FTO) glass substrates at various substrate temperatures by spray pyrolysis. The photoelectrochemical cell configurations were In{sub 2}Se{sub 3} thin film/1 M (NaOH + Na{sub 2}S + S)/C. From capacitance–voltage (C–V) and current–voltage (I–V) characteristics; it is concluded that In{sub 2}Se{sub 3} thin films are of n-type. The Fill factor (FF) and solar conversion efficiency (η) were calculated from photovoltaic power output characteristics. In this instance, the highest measured photocurrent density of 1.05 mA/cm{sup 2} and open circuit voltage of 261 mV is observed for film deposited at 350 °C resulting in maximum power conversion efficiency (η) and fill factor (FF) to be 0.71% and 0.51% respectively. Electrochemical impedance spectroscopy study shows that the In{sub 2}Se{sub 3} film deposited at 350 °C shows better performance in photoelectrochemical cell. The performance of indium selenide thin film observed in our work can motivate further studies concerning solar energy conversion.

Preparation of PZT/YBCO/YAlO heterostructure thin films by KrF excimer laser ablation

International Nuclear Information System (INIS)

Ebihara, Kenji; Kurogi, Hiromitsu; Yamagata, Yukihiko; Ikegami, Tomoaki; Grishin, A.M.

1998-01-01

The perovskite oxide YBa 2 Cu 3 O 7-x (YBCO) and Pb(Zr x Ti 1-x )O 3 (PZT) thin films have been deposited for superconducting-ferroelectric devices. KrF excimer laser ablation technique was used at the deposition conditions of 200--600 mTorr O 2 , 2-3J/cm 2 and 5--10 Hz operation frequency. Heterostructures of PZT-YBCO-YAlO 3 :Nd show the zero resistivity critical temperature of 82 K and excellent ferroelectric properties of remnant polarization 32 microC/cm 2 , coercive force of 80 kV/cm and dielectric constant 800. Cycling fatigue characteristics and leakage current are also discussed

Crystallized InBiS3 thin films with enhanced optoelectronic properties

Science.gov (United States)

Ali, N.; Hussain, Arshad; Ahmed, R.; Omar, M. Firdaus Bin; Sultan, M.; Fu, Yong Qing

2018-04-01

In this paper, a one-step thermal evaporation approach was used for fabrication of indium bismuth sulphide thin films, and the synergetic effects of co-evaporation of two sources (indium granules and Bi2S3 powders) were investigated using different characterization techniques. X-ray diffraction (XRD) analysis confirmed the crystalline orthorhombic structure for the post-annealed samples. Surface roughness and crystal size of the obtained film samples were increased with increasing annealing temperatures. Analysis using X-ray photoelectron spectroscopy showed the formation of the InBiS3 structure for the obtained films, which is also confirmed by the XRD results. The optical absorption coefficient value of the annealed samples was found to be in the order of 105 cm-1 in the visible region of the solar spectrum. The optical band gap energy and electrical resistivity of the fabricated samples were observed to decrease (from 2.2 to 1.3 eV, and from 0.3 to 0.01 Ω-cm, respectively) with increasing annealing temperatures (from 200 to 350 °C), indicating the suitability of the prepared InBiS3 thin films for solar cell applications.

Effect of Nitrogen Content on Physical and Chemical Properties of TiN Thin Films Prepared by DC Magnetron Sputtering with Supported Discharge

Science.gov (United States)

Kavitha, A.; Kannan, R.; Gunasekhar, K. R.; Rajashabala, S.

2017-10-01

Amorphous titanium nitride (TiN) thin films have been prepared on silicon (Si) and glass substrates by direct-current (DC) reactive magnetron sputtering with a supported discharge (triode). Nitrogen gas (N2) at partial pressure of 0.3 Pa, 0.4 Pa, 0.5 Pa, and 0.6 Pa was used to prepare the TiN thin films, maintaining total pressure of argon and N2 of about 0.7 Pa. The chemical, microstructural, optical, and electrical properties of the TiN thin films were systematically studied. Presence of different phases of Ti with nitrogen (N), oxygen (O2), and carbon (C) elements was revealed by x-ray photoelectron spectroscopy characterization. Increase in the nitrogen pressure from 0.3 Pa to 0.6 Pa reduced the optical bandgap of the TiN thin film from 2.9 eV to 2.7 eV. Photoluminescence study showed that TiN thin film deposited at N2 partial pressure of 0.3 Pa exhibited three shoulder peaks at 330 nm, 335 nm, and 340 nm, which disappeared when the sample was deposited with N2 partial pressure of 0.6 Pa. Increase in the nitrogen content decreased the electrical resistivity of the TiN thin film from 3200 μΩ cm to 1800 μΩ cm. Atomic force microscopy studies of the TiN thin films deposited with N2 partial pressure of 0.6 Pa showed a uniform surface pattern associated with accumulation of fine grains. The results and advantages of this method of preparing TiN thin films are also reported.

Nonvolatile memory thin-film transistors using biodegradable chicken albumen gate insulator and oxide semiconductor channel on eco-friendly paper substrate.

Science.gov (United States)

Kim, So-Jung; Jeon, Da-Bin; Park, Jung-Ho; Ryu, Min-Ki; Yang, Jong-Heon; Hwang, Chi-Sun; Kim, Gi-Heon; Yoon, Sung-Min

2015-03-04

Nonvolatile memory thin-film transistors (TFTs) fabricated on paper substrates were proposed as one of the eco-friendly electronic devices. The gate stack was composed of chicken albumen gate insulator and In-Ga-Zn-O semiconducting channel layers. All the fabrication processes were performed below 120 °C. To improve the process compatibility of the synthethic paper substrate, an Al2O3 thin film was introduced as adhesion and barrier layers by atomic layer deposition. The dielectric properties of biomaterial albumen gate insulator were also enhanced by the preparation of Al2O3 capping layer. The nonvolatile bistabilities were realized by the switching phenomena of residual polarization within the albumen thin film. The fabricated device exhibited a counterclockwise hysteresis with a memory window of 11.8 V, high on/off ratio of approximately 1.1 × 10(6), and high saturation mobility (μsat) of 11.5 cm(2)/(V s). Furthermore, these device characteristics were not markedly degraded even after the delamination and under the bending situration. When the curvature radius was set as 5.3 cm, the ION/IOFF ratio and μsat were obtained to be 5.9 × 10(6) and 7.9 cm(2)/(V s), respectively.

Directed self-assembly of nanoporous metallic- and bimetallic nanoparticle thin films

Energy Technology Data Exchange (ETDEWEB)

Pietsch, Torsten [Fachbereich Physik, Universitaet Konstanz (Germany); Gindy, Nabil; Fahmi, Amir [Department of Mechanical, Materials and Manufacturing Engineering, University of Nottingham (United Kingdom)

2010-07-01

Nanoporous thin films attracted considerable interest due to potential applications in optical coatings, catalysis, sensors as well as electronic devices. Recently, such films were prepared by post deposition treatments. The present study is focused on the fabrication of nanoporous thin films via directed self-assembly of hybrid materials. Due to the nature of this process no additional treatments are necessary to develop the pores. Hierarchical nanoporous structures are fabricated directly via deposition of polymer templated Au-nanoparticles onto hydrophilic substrates. These films exhibit two different pore diameters and a total pore density of more than 10{sup 10} holes per cm{sup 2}. Control over the pore size is achieved by changing the molecular weight of the PS-b-P4VP diblock copolymer. Moreover, the porous morphology is used as a template to fabricate bimetallic nanostructured thin films. Such well-defined nanostructures, not only exhibit unique physical properties but also provide control over the hydrophobicity of the coated surfaces.

Chemical vapor deposition based tungsten disulfide (WS2) thin film transistor

KAUST Repository

Hussain, Aftab M.

2013-04-01

Tungsten disulfide (WS2) is a layered transition metal dichalcogenide with a reported band gap of 1.8 eV in bulk and 1.32-1.4 eV in its thin film form. 2D atomic layers of metal dichalcogenides have shown changes in conductivity with applied electric field. This makes them an interesting option for channel material in field effect transistors (FETs). Therefore, we show a highly manufacturable chemical vapor deposition (CVD) based simple process to grow WS2 directly on silicon oxide in a furnace and then its transistor action with back gated device with room temperature field effect mobility of 0.1003 cm2/V-s using the Schottky barrier contact model. We also show the semiconducting behavior of this WS2 thin film which is more promising than thermally unstable organic materials for thin film transistor application. Our direct growth method on silicon oxide also holds interesting opportunities for macro-electronics applications. © 2013 IEEE.

Superior light trapping in thin film silicon solar cells through nano imprint lithography

Energy Technology Data Exchange (ETDEWEB)

Soppe, W.J.; Dorenkamper, M.S.; Schropp, R.E.I.; Pex, P.P.A.C.

2013-10-15

ECN and partners have developed a fabrication process based on nanoimprint lithography (NIL) of textures for light trapping in thin film solar cells such as thin-film silicon, OPV, CIGS and CdTe. The process can be applied in roll-to-roll mode when using a foil substrate or in roll-to-plate mode when using a glass substrate. The lacquer also serves as an electrically insulating layer for cells if steel foil is used as substrate, to enable monolithic series interconnection. In this paper we will show the superior light trapping in thin film silicon solar cells made on steel foil with nanotextured back contacts. We have made single junction a-Si and {mu}c-Si and a-Si/{mu}c-Si tandem cells, where we applied several types of nano-imprints with random and periodic structures. We will show that the nano-imprinted back contact enables more than 30% increase of current in comparison with non-textured back contacts and that optimized periodic textures outperform state-of-the-art random textures. For a-Si cells we obtained Jsc of 18 mA/cm{sup 2} and for {mu}c-Si cells more than 24 mA/cm{sup 2}. Tandem cells with a total Si absorber layer thickness of only 1350 nm have an initial efficiency of 11%.

Low temperature ITO thin film deposition on PES substrate using pulse magnetron sputtering

International Nuclear Information System (INIS)

Lin, Y.C.; Li, J.Y.; Yen, W.T.

2008-01-01

Experiments were conducted using pulse magnetron sputtering (PMS) to deposit transparent conducting indium tin oxide (ITO) thin film onto flexible polyethersulfone (PES) plastic substrates. The thin film microstructure, optoelectronic and residual stress were analyzed using the modulating PMS power, work pressure, pulse frequency, duty cycle and cycle time process parameters. The residual stress of the thin film was determined by scanning electron microscopy (SEM) combined with the Sony equation. The experimental results show that PMS has a lower process temperature, higher deposition rate and lower resistivity compared with the radio frequency process at the same output power. The duty cycle increase produces the optimum optoelectronic characteristics. When the pressure, power, duty cycle and sputter time are increased, the thin film stress will also increase, causing flexural distortion in the PES plastic substrate. When the deposition thickness reaches 1.5 μm, ITO thin film will appear with a distinct split. Under 5 mtorr work pressure, 60 W power, 33 μs duty time and 2 μs pulse reverse time at duty cycle 95%, thin film with an optimized electrical 3.0 x 10 -4 Ω-cm, RMS surface roughness of 0.85 nm and visible region optical transmittance will be achieved with acquisition of over 85%

Morphometric study of uninvolved rectal mucosa 10 cm and 20 cm away from the malignant tumor.

Science.gov (United States)

Despotović, Sanja Z; Milićević, Novica M; Milosević, Dragoslav P; Despotović, Nebojsa; Erceg, Predrag; Bojić, Bozidar; Bojić, Danijela; Svorcan, Petar; Mihajlović, Gordana; Dorđević, Jelena; Lalić, Ivana M; Milićević, Zivana

2014-02-01

Recently, many details of the interplay between tumor cells and tumor-associated stromal elements leading to the progression of malignant disease were elucidated. In contrast, little is known about the role of uninvolved stromal tissue in the remote surrounding of the malignant tumor. Therefore, we performed a computer-aided morphometric study of rectal mucosa in samples taken 10 cm and 20 cm away from the malignant tumor during endoscopic examination of 23 patients older than 60 years. The samples of rectal mucosa from 10 healthy persons of corresponding age subjected to diagnostic rectoscopy during active screening for asymptomatic cancer were used as control. All structural elements of the rectal mucosa were studied and the number of nucleated cells in the lamina propria per 0.1 mm² of tissue was assessed. Our study revealed a reduced number of cells in the lamina propria of the rectal mucosa 10 cm and 20 cm away from the tumor lesion in both male and female patients. The decreased mucosal height and increased crypt number were registered in female patients 10 cm away from the tumor. The connective tissue of lamina propria showed a disorderly organization: the collagen fibers were frail, loosely arranged and signs of tissue edema were present. Small blood vessels and capillaries were much more frequently seen than in healthy tissue. Our results demonstrate the complex interactions between the cancer and remote mucosal tissue of the affected organ.

Fiscal 1998 New Sunshine Program achievement report. Development for practical application of photovoltaic system - Development of thin-film solar cell manufacturing technology (Development of low-cost large-area module manufacturing technology - Development of next-generation thin-film solar cell manufacturing technology - Development of thin-film polycrystalline solar cell module manufacturing technology); 1998 nendo taiyoko hatsuden system jitsuyoka gijutsu kaihatsu seika hokokusho. Usumaku taiyo denchi no seizo gijutsu kaihatsu / tei cost daimenseki module seizo gijutsu kaihatsu / jisedai usumaku taiyo denchi no seizo gijutsu kaihatsu (usumaku takessho taiyo denchi module no seizo gijutsu kaihatsu)

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

The aim is to realize the practical application of the above-named solar module expected to exhibit higher efficiency and reliability and achieve cost reduction through consumption of less materials. In fiscal 1998, 1) technologies were developed to reduce substrate warpage during recrystallization for the higher-throughput fabrication of high-quality thin films and 2) technologies were also developed for the realization of higher-throughput fabrication of thin films and for efficiency improvement for thin-film modules. Under item 1), experiments were conducted by simulation for reducing warpage to occur in thin-film polycrystalline Si substrates during fabrication by melting and recrystallization. Under item 2), for the development of thin-film cell high-throughput technologies, studies were started on a more practical hydrogen plasma process to challenge the conventional process of crystal defect inactivation by hydrogen ion injection with which achievement of high throughputs is difficult. For the development of technologies for the enhancement of thin-film module efficiency, efforts were exerted to realize a 10cm times 10cm square shape for the enhancement of efficiency in the process of filling modules with cells. These efforts achieved a great step toward future practical application. (NEDO)

Defect control in room temperature deposited cadmium sulfide thin films by pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Hernandez-Como, N. [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX, 75080 (United States); Martinez-Landeros, V. [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX, 75080 (United States); Centro de Investigación en Materiales Avanzados, Monterrey, Nuevo Leon, 66600, México (Mexico); Mejia, I. [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX, 75080 (United States); Aguirre-Tostado, F.S. [Centro de Investigación en Materiales Avanzados, Monterrey, Nuevo Leon, 66600, México (Mexico); Nascimento, C.D.; Azevedo, G. de M; Krug, C. [Instituto de Física, Universidade Federal do Rio Grande do Sul, Porto Alegre, 91509-900 (Brazil); Quevedo-Lopez, M.A., E-mail: mquevedo@utdallas.edu [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX, 75080 (United States)

2014-01-01

The control of defects in cadmium sulfide thin films and its impact on the resulting CdS optical and electrical characteristics are studied. Sulfur vacancies and cadmium interstitial concentrations in the CdS films are controlled using the ambient pressure during pulsed laser deposition. CdS film resistivities ranging from 10{sup −1} to 10{sup 4} Ω-cm are achieved. Hall Effect measurements show that the carrier concentration ranges from 10{sup 19} to 10{sup 13} cm{sup −3} and is responsible for the observed resistivity variation. Hall mobility varies from 2 to 12 cm{sup 2}/V-s for the same pressure regime. Although the energy bandgap remains unaffected (∼ 2.42 eV), the optical transmittance is reduced due to the increase of defects in the CdS films. Rutherford back scattering spectroscopy shows the dependence of the CdS films stoichiometry with deposition pressure. The presence of CdS defects is attributed to more energetic species reaching the substrate, inducing surface damage in the CdS films during pulsed laser deposition. - Highlights: • CdS thin films deposited by pulsed laser deposition at room temperature. • The optical, electrical and structural properties were evaluated. • Carrier concentration ranged from 10{sup 19} to 10{sup 13} cm{sup −3}. • The chemical composition was studied by Rutherford back scattering. • The density of sulfur vacancies and cadmium interstitial was varied.

Chemically fabricated LiFePO{sub 4} thin film electrode for transparent batteries and electrochromic devices

Energy Technology Data Exchange (ETDEWEB)

Béléké, Alexis B. [Institut de recherche d’Hydro-Québec, 1800 Boul. Lionel-Boulet, Varennes, QC J3X 1S3 (Canada); Department of Mining and Materials Engineering, McGill University, M.H. Wong Building, 3610 rue University, Montréal, QC H3A 2B2 (Canada); Faure, Cyril [Institut de recherche d’Hydro-Québec, 1800 Boul. Lionel-Boulet, Varennes, QC J3X 1S3 (Canada); Röder, Manuel [Center for Applied Electrochemistry, Fraunhofer Institute for Silicate Research, Neunerplatz 2, 97083 Würzburg (Germany); Hovington, Pierre [Institut de recherche d’Hydro-Québec, 1800 Boul. Lionel-Boulet, Varennes, QC J3X 1S3 (Canada); Posset, Uwe [Center for Applied Electrochemistry, Fraunhofer Institute for Silicate Research, Neunerplatz 2, 97083 Würzburg (Germany); Guerfi, Abdelbast [Institut de recherche d’Hydro-Québec, 1800 Boul. Lionel-Boulet, Varennes, QC J3X 1S3 (Canada); Zaghib, Karim, E-mail: zaghib.karim@ireq.ca [Institut de recherche d’Hydro-Québec, 1800 Boul. Lionel-Boulet, Varennes, QC J3X 1S3 (Canada)

2016-12-15

Graphical abstract: Simplified diagram of the novel sol-gel approach of preparation of colorless and transparent LiFePO{sub 4} thin film electrode. - Highlights: • Novel sol-gel synthesis of colorless LFP thin film electrode for transparent Li-ion battery. • High performance of the electrode at various current densities: 5, 10, 20, 50 and 100 μA/cm{sup 2}. • LFP nanoparticles exhibit an excellent electro-activity. • Colorless LFP thin film shows a transmittance above 80% versus FTO. • Higher transmittance of LFP electrode a potential candidate for electrochromic devices. - Abstract: We report a new sol-gel approach of synthesis of LiFePO{sub 4} (LFP) thin film and its application as cathode materials for transparent Li-ion battery in half-cell configuration. LFP thin films were obtained from an alcoholic colloidal suspension of iron acetylacetonate (Fe(AcAc){sub 3}) and aqueous lithium dihydrogen phosphate (LiH{sub 2}PO{sub 4}) deposited on fluorine tin oxide (FTO) glass substrate, followed by heating at 450 °C under nitrogen gas for 1 h. X-ray diffraction (XRD) confirmed that the LFP films have an orthorhombic crystal system with space group Pnma (62). Scanning electron microscopy (SEM) shows spherical LFP nanoparticles aggregates homogenously deposited all over the surface of FTO substrate containing 3-D open pores. The electrochemical behaviors of thin film vs Li/Li{sup +} cell were investigated by cyclic voltammetry and galvanostatic charge-discharge measurements. The cycle life was evaluated by running 1000 cycles of charge-discharge at a current density of 20 μA/cm{sup 2}. The transmission spectra reveal 85–90% of transparency versus FTO as reference, which makes it a potential candidate as a complementary electrode in electrochromic devices (ECDs).

Study of working pressure on the optoelectrical properties of Al–Y codoped ZnO thin-film deposited using DC magnetron sputtering for solar cell applications

International Nuclear Information System (INIS)

Hsu, Feng-Hao; Wang, Na-Fu; Tsai, Yu-Zen; Chuang, Ming-Chieh; Cheng, Yu-Song; Houng, Mau-Phon

2013-01-01

Low cost transparent conductive Al–Y codoped ZnO (AZOY) thin-films were prepared on a glass substrate using a DC magnetron sputtering technique with various working pressures in the range of 5–13 mTorr. The relationship among the structural, electrical, and optical properties of sputtered AZOY films was studied as a function of working pressure. The XRD measurements show that the crystallinity of the films degraded as the working gas pressure increased. The AZOY thin-film deposited at a working pressure of 5 mTorr exhibited the lowest electrical resistivity of 4.3 × 10 −4 Ω cm, carrier mobility of 30 cm 2 /V s, highest carrier concentration of 4.9 × 10 20 cm −3 , and high transmittance in the visible region (400–800 nm) of approximately 90%. Compared with Al doped ZnO (AZO) thin-films deposited using DC or RF magnetron sputtering methods, a high carrier mobility was observed in our AZOY thin-films. This result can be used to effectively decrease the absorption of near infrared-rays in solar cell applications. The mechanisms are attributed to the larger transition energy between Ar atoms and sputtering particles and the size compensation of the dopants. Finally, the optimal quality AZOY thin-film was used as an emitter layer (or window layer) to form AZOY/n-Si heterojunction solar cells, which exhibited a stable conversion efficiency (η) of 9.4% under an AM1.5 illumination condition.

Nanostructured hematite thin films for photoelectrochemical water splitting

Science.gov (United States)

Maabong, Kelebogile; Machatine, Augusto G. J.; Mwankemwa, Benard S.; Braun, Artur; Bora, Debajeet K.; Toth, Rita; Diale, Mmantsae

2018-04-01

Nanostructured hematite thin films prepared by dip coating technique were investigated for their photoelectrochemical activity for generation of hydrogen from water splitting. Structural, morphological and optical analyses of the doped/undoped films were performed by X-ray diffraction, high resolution field emission-scanning electron microscopy, UV-vis spectrophotometry and Raman spectroscopy. The photoelectrochemical measurements of the films showed enhanced photoresponse and cathodic shift of the onset potential upon Ti doping indicating improved transfer of photoholes at the semiconductor-electrolyte interface. Films doped with 1 at% Ti produced 0.72 mA/cm2 at 1.23 V vs RHE which is 2 times higher than current density for the pure film (0.30 mA/cm2, at 1.23 V vs RHE). Gas chromatography analysis of the films also showed enhanced hydrogen evolution at 1 at% Ti with respect to pure film.

Effect of Annealing Temperature on Flowerlike Cu3BiS3 Thin Films Grown by Chemical Bath Deposition

Science.gov (United States)

Deshmukh, S. G.; Patel, S. J.; Patel, K. K.; Panchal, A. K.; Kheraj, Vipul

2017-10-01

For widespread application of thin-film photovoltaic solar cells, synthesis of inexpensive absorber material is essential. In this work, deposition of ternary Cu3BiS3 absorber material, which contains abundant and environmentally benign elements, was carried out on glass substrate. Flowerlike Cu3BiS3 thin films with nanoflakes as building block were formed on glass substrate by chemical bath deposition. These films were annealed at 573 K and 673 K in sulfur ambient for structural improvement. Their structure was characterized using Raman spectroscopy, as well as their surface morphological and optical properties. The x-ray diffraction profile of as-deposited Cu3BiS3 thin film revealed amorphous structure, which transformed to orthorhombic phase after annealing. The Raman spectrum exhibited a characteristic peak at 290 cm-1. Scanning electron microscopy of as-deposited Cu3BiS3 film confirmed formation of nanoflowers with diameter of around 1052 nm. Wettability testing of as-deposited Cu3BiS3 thin film demonstrated hydrophobic nature, which became hydrophilic after annealing. The measured ultraviolet-visible (UV-Vis) absorption spectra of the Cu3BiS3 thin films gave an absorption coefficient of 105 cm-1 and direct optical bandgap of about 1.42 eV after annealing treatment. Based on all these results, such Cu3BiS3 material may have potential applications in the photovoltaic field as an absorber layer.

Magnetic and topographical modifications of amorphous Co–Fe thin films induced by high energy Ag{sup 7+} ion irradiation

Energy Technology Data Exchange (ETDEWEB)

Pookat, G.; Hysen, T. [Department of Physics, Cochin University of Science and Technology, Cochin 682022, Kerala (India); Al-Harthi, S.H.; Al-Omari, I.A. [Department of Physics, Sultan Qaboos University, Muscat, P.O. Box 36, Code 123 (Oman); Lisha, R. [Department of Physics, Cochin University of Science and Technology, Cochin 682022, Kerala (India); Avasthi, D.K. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110 067 (India); Anantharaman, M.R., E-mail: mra@gmail.com [Department of Physics, Cochin University of Science and Technology, Cochin 682022, Kerala (India)

2013-09-01

We have investigated the effects of swift heavy ion irradiation on thermally evaporated 44 nm thick, amorphous Co{sub 77}Fe{sub 23} thin films on silicon substrates using 100 MeV Ag{sup 7+} ions fluences of 1 × 10{sup 11} ions/cm{sup 2}, 1 × 10{sup 12} ions/cm{sup 2}, 1 × 10{sup 13} ions/cm{sup 2}, and 3 × 10{sup 13} ions/cm{sup 2}. The structural modifications upon swift heavy irradiation were investigated using glancing angle X-ray diffraction. The surface morphological evolution of thin film with irradiation was studied using Atomic Force Microscopy. Power spectral density analysis was used to correlate the roughness variation with structural modifications investigated using X-ray diffraction. Magnetic measurements were carried out using vibrating sample magnetometry and the observed variation in coercivity of the irradiated films is explained on the basis of stress relaxation. Magnetic force microscopy images are subjected to analysis using the scanning probe image processor software. These results are in agreement with the results obtained using vibrating sample magnetometry. The magnetic and structural properties are correlated.

Precise measurement of the transverse piezoelectric coefficient for thin films on anisotropic substrate

International Nuclear Information System (INIS)

Chun, Doo-Man; Sato, Masashi; Kanno, Isaku

2013-01-01

In this study, we propose a reliable measurement method for the effective transverse piezoelectric coefficient for thin films especially on anisotropic substrate. This coefficient for piezoelectric Pb(Zr, Ti)O 3 (PZT) thin films was calculated by measuring the electric field-induced tip displacement of unimorph cantilevers composed of PZT thin films and Si substrates. We evaluated the reliability of the proposed measurement method by comparing it with numerical analysis and confirmed that the relative error of the piezoelectric coefficient (e 31,f ) was less than 1%. We prepared 16 different unimorph cantilevers composed of identical PZT films on different Si beam geometries that had various substrate thicknesses and cantilever widths. Although the effective transverse piezoelectric coefficient e 31,f of PZT thin films ranged from −6.5 to −14 C/m 2 as a function of the applied voltage, the difference among the 16 samples with an applied voltage of 25 V was within 10%. These results demonstrate that the proposed measurement method has sufficient reliability and can be used to evaluate the effective transverse piezoelectric coefficient e 31,f of thin films.

Indium-tin-oxide thin film deposited by a dual ion beam assisted e-beam evaporation system

International Nuclear Information System (INIS)

Bae, J.W.; Kim, J.S.; Yeom, G.Y.

2001-01-01

Indium-tin-oxide (ITO) thin films were deposited on polycarbonate (PC) substrates at low temperatures (<90 deg. C) by a dual ion beam assisted e-beam evaporation system, where one gun (gun 1) is facing ITO flux and the other gun (gun 2) is facing the substrate. In this experiment, effects of rf power and oxygen flow rate of ion gun 2 on the electrical and optical properties of depositing ITO thin films were investigated. At optimal deposition conditions, ITO thin films deposited on the PC substrates larger than 20 cmx20 cm showed the sheet resistance of less than 40 Ω/sq., the optical transmittance of above 90%, and the uniformity of about 5%

Growth and characterization of chalcostibite CuSbSe2 thin films for photovoltaic application

Science.gov (United States)

Tiwari, Kunal J.; Vinod, Vijay; Subrahmanyam, A.; Malar, P.

2017-10-01

Bulk copper antimony selenide was synthesized using mechanical alloying from the elemental precursors. Phase formation in milled powders was studied using x-ray diffraction (XRD) and Raman spectroscopy studies. The synthesized bulk source after cold compaction was used as source material for thin film deposition by e-beam evaporation. Thin film deposition was carried out at various e-beam current values (Ib ∼30, 40 and 50 mA) and at a substrate temperature of 200 °C. Near stoichiometric CuSbSe2 thin films were obtained for Ib values closer to 50 mA and post annealing at a temperature of 380 °C for 1 h. Thin films deposited using above conditions were found to exhibit an absorption coefficient (α) values of >105 cm-1 and a band gap value ∼1.18 eV that is closer to the reported band gap for CuSbSe2 compound.

Preparation of anatase TiO{sub 2} thin films by vacuum arc plasma evaporation

Energy Technology Data Exchange (ETDEWEB)

Miyata, Toshihiro [Optoelectronic Device System R and D Center, Kanazawa Institute of Technology, 7-1 Ohgigaoka, Nonoichi, Ishikawa 921-8501 (Japan)]. E-mail: tmiyata@neptune.kanazawa-it.ac.jp; Tsukada, Satoshi [Optoelectronic Device System R and D Center, Kanazawa Institute of Technology, 7-1 Ohgigaoka, Nonoichi, Ishikawa 921-8501 (Japan); Minami, Tadatsugu [Optoelectronic Device System R and D Center, Kanazawa Institute of Technology, 7-1 Ohgigaoka, Nonoichi, Ishikawa 921-8501 (Japan)

2006-02-01

Anatase titanium dioxide (TiO{sub 2}) thin films with high photocatalytic activity have been prepared with deposition rates as high as 16 nm/min by a newly developed vacuum arc plasma evaporation (VAPE) method using sintered TiO{sub 2} pellets as the source material. Highly transparent TiO{sub 2} thin films prepared at substrate temperatures from room temperature to 400 deg. C exhibited photocatalytic activity, regardless whether oxygen (O{sub 2}) gas was introduced during the VAPE deposition. The highest photocatalytic activity and photo-induced hydrophilicity were obtained in anatase TiO{sub 2} thin films prepared at 300 deg. C, which correlated to the best crystallinity of the films, as evidenced from X-ray diffraction. In addition, a transparent and conductive anatase TiO{sub 2} thin film with a resistivity of 2.6 x 10{sup -1} {omega} cm was prepared at a substrate temperature of 400 deg. C without the introduction of O{sub 2} gas.

Polyurethane coating with thin polymer films produced by plasma polymerization of diglyme

International Nuclear Information System (INIS)

Ribeiro, M A; Ramos, A S; Manfredini, M I; Alves, H A; Ramos, E C T; Honda, R Y; Kostov, K G; Lucena, E F; Mota, R P; Algatti, M A; Kayama, M E

2009-01-01

Aqueous-based polyurethane dispersions have been widely utilized as lubricants in textile, shoes, automotive, biomaterial and many other industries because they are less aggressive to surrounding environment. In this work thin films with different thickness were deposited on biocompatible polyurethane by plasma polymerization process using diethylene glycol dimethyl ether (Diglyme) as monomer. Molecular structure of the films was analyzed by Fourier Transform Infrared spectroscopy. The spectra exhibited absorption bands of O-H (3500-3200cm -1 ), C-H (3000-2900cm -1 ), C=O (1730-1650cm -1 ), C-O and C-O-C bonds at 1200-1600cm -1 . The samples wettability was evaluated by measurements of contact angle using different liquids such as water, glycerol, poly-ethane and CMC. The polyurethane surface showed hydrophilic behavior after diglyme plasma-deposition with contact angle dropping from 85 deg. to 22 deg. Scanning Electron Microscopy revealed that diglyme films covered uniformly the polyurethane surfaces ensuring to it a biocompatible characteristic.

Polyurethane coating with thin polymer films produced by plasma polymerization of diglyme

Science.gov (United States)

Ribeiro, M. A.; Ramos, A. S.; Manfredini, M. I.; Alves, H. A.; Y Honda, R.; Kostov, K. G.; Lucena, E. F.; Ramos, E. C. T.; Mota, R. P.; Algatti, M. A.; Kayama, M. E.

2009-05-01

Aqueous-based polyurethane dispersions have been widely utilized as lubricants in textile, shoes, automotive, biomaterial and many other industries because they are less aggressive to surrounding environment. In this work thin films with different thickness were deposited on biocompatible polyurethane by plasma polymerization process using diethylene glycol dimethyl ether (Diglyme) as monomer. Molecular structure of the films was analyzed by Fourier Transform Infrared spectroscopy. The spectra exhibited absorption bands of O-H (3500-3200cm-1), C-H (3000-2900cm-1), C=O (1730-1650cm-1), C-O and C-O-C bonds at 1200-1600cm-1. The samples wettability was evaluated by measurements of contact angle using different liquids such as water, glycerol, poly-ethane and CMC. The polyurethane surface showed hydrophilic behavior after diglyme plasma-deposition with contact angle dropping from 85° to 22°. Scanning Electron Microscopy revealed that diglyme films covered uniformly the polyurethane surfaces ensuring to it a biocompatible characteristic.

Polyurethane coating with thin polymer films produced by plasma polymerization of diglyme

Energy Technology Data Exchange (ETDEWEB)

Ribeiro, M A; Ramos, A S; Manfredini, M I; Alves, H A; Ramos, E C T [UNIVAP, Sao Jose dos Campos, SP (Brazil); Honda, R Y; Kostov, K G; Lucena, E F; Mota, R P; Algatti, M A; Kayama, M E, E-mail: rmota@feg.unesp.b [FEG-DFQ-UNESP, Av. Ariberto Pereira da Cunha 333, 12516-410 - Guaratingueta, SP (Brazil)

2009-05-01

Aqueous-based polyurethane dispersions have been widely utilized as lubricants in textile, shoes, automotive, biomaterial and many other industries because they are less aggressive to surrounding environment. In this work thin films with different thickness were deposited on biocompatible polyurethane by plasma polymerization process using diethylene glycol dimethyl ether (Diglyme) as monomer. Molecular structure of the films was analyzed by Fourier Transform Infrared spectroscopy. The spectra exhibited absorption bands of O-H (3500-3200cm{sup -1}), C-H (3000-2900cm{sup -1}), C=O (1730-1650cm{sup -1}), C-O and C-O-C bonds at 1200-1600cm{sup -1}. The samples wettability was evaluated by measurements of contact angle using different liquids such as water, glycerol, poly-ethane and CMC. The polyurethane surface showed hydrophilic behavior after diglyme plasma-deposition with contact angle dropping from 85 deg. to 22 deg. Scanning Electron Microscopy revealed that diglyme films covered uniformly the polyurethane surfaces ensuring to it a biocompatible characteristic.

Magnetic Property in Large Array Niobium Antidot Thin Films

Science.gov (United States)

Tinghui, Chen; Hsiang-Hsi, Kung; Wei-Li, Lee; Institute of Physics, Academia Sinica, Taipei, Taiwan Team

2014-03-01

In a superconducting ring, the total flux inside the ring is required to be an integer number of the flux quanta. Therefore, a supercurrent current can appear within the ring in order to satisfy this quantization rule, which gives rise to certain magnetic response. By using a special monolayer polymer/nanosphere hybrid we developed previously, we fabricated a series of superconducting niobium antidot thin films with different antidot diameters. The antidots form well-ordered triangular lattice with a lattice spacing about 200 nm and extend over an area larger than 1 cm2, which enables magnetic detections simply by a SQUID magnetometer. We observed magnetization oscillation with external magnetic field due to the supercurrent screening effect, where different features for large and small antidot thin films were found. Detailed size and temperature dependencies of the magnetization in niobium antidot nanostructures will be presented.

Room temperature deposition of ZnSe thin films by successive ionic layer adsorption and reaction (SILAR) method

International Nuclear Information System (INIS)

Kale, R.B.; Lokhande, C.D.

2004-01-01

The zinc selenide (ZnSe) thin films are deposited onto glass substrate using relatively simple and inexpensive successive ionic layer adsorption and reaction (SILAR) method. The films are deposited using zinc acetate sodium selenosulphate precursors. The concentration, pH, immersion and rinsing times and number of immersion cycles have been optimized to obtain good quality ZnSe thin films. The X-ray diffraction (XRD) study and scanning electron microscopy (SEM) studies reveals nanocrystalline nature alongwith some amorphous phase present in ZnSe thin films. Energy dispersive X-ray (EDAX) analysis shows that the films are Se deficient. From optical absorption data, the optical band gap 'E g ' for as-deposited thin film was found to be 2.8 eV and electrical resistivity in the order of 10 7 Ω cm

Influence of stress on the structural and dielectric properties of rf magnetron sputtered zinc oxide thin film

Science.gov (United States)

Menon, Rashmi; Sreenivas, K.; Gupta, Vinay

2008-05-01

Highly c axis oriented zinc oxide (ZnO) thin films have been prepared on 1737 Corning glass substrate by planar rf magnetron sputtering under varying pressure (10-50mTorr) and different oxygen percentage (40%-100%) in reactive gas mixtures. The as-grown ZnO thin films were found to have stress over a wide range from -6×1010to-9×107dynes/cm2. The presence of stress depends strongly on processing conditions, and films become almost stress free under a unique combination of sputtering pressure and reactive gas composition. The studies show a correlation of stress with structural and electrical properties of the ZnO thin film. The stressed films possess high electrical conductivity and exhibits strong dielectric dispersion over a wide frequency (1kHz-1MHz). The dielectric constant ɛ'(ω) of stress free ZnO film was almost frequency independent and was close to the bulk value. The measured value of dc conductivity, σdc(ω) and ac conductivity σac(ω) of stress free ZnO film was 1.3×10-9 and 6.8×10-5Ω-1cm-1, respectively. The observed variation in the structural and electrical properties of ZnO thin film with stress has been analyzed in the light of growth kinetics.

The Cu2ZnSnSe4 thin films solar cells synthesized by electrodeposition route

Science.gov (United States)

Li, Ji; Ma, Tuteng; Wei, Ming; Liu, Weifeng; Jiang, Guoshun; Zhu, Changfei

2012-06-01

An electrodeposition route for preparing Cu2ZnSnSe4 thin films for thin film solar cell absorber layers is demonstrated. The Cu2ZnSnSe4 thin films are prepared by co-electrodeposition Cu-Zn-Sn metallic precursor and subsequently annealing in element selenium atmosphere. The structure, composition and optical properties of the films were investigated by X-ray diffraction (XRD), Raman spectrometry, energy dispersive spectrometry (EDS) and UV-VIS absorption spectroscopy. The Cu2ZnSnSe4 thin film with high crystalline quality was obtained, the band gap and absorption coefficient were 1.0 eV and 10-4 cm-1, which is quite suitable for solar cells fabrication. A solar cell with the structure of ZnO:Al/i-ZnO/CdS/Cu2ZnSnSe4/Mo/glass was fabricated and achieved an conversion efficiency of 1.7%.

Radiation hardness of thin Low Gain Avalanche Detectors

Science.gov (United States)

Kramberger, G.; Carulla, M.; Cavallaro, E.; Cindro, V.; Flores, D.; Galloway, Z.; Grinstein, S.; Hidalgo, S.; Fadeyev, V.; Lange, J.; Mandić, I.; Medin, G.; Merlos, A.; McKinney-Martinez, F.; Mikuž, M.; Quirion, D.; Pellegrini, G.; Petek, M.; Sadrozinski, H. F.-W.; Seiden, A.; Zavrtanik, M.

2018-05-01

Low Gain Avalanche Detectors (LGAD) are based on a n++-p+-p-p++ structure where an appropriate doping of the multiplication layer (p+) leads to high enough electric fields for impact ionization. Gain factors of few tens in charge significantly improve the resolution of timing measurements, particularly for thin detectors, where the timing performance was shown to be limited by Landau fluctuations. The main obstacle for their operation is the decrease of gain with irradiation, attributed to effective acceptor removal in the gain layer. Sets of thin sensors were produced by two different producers on different substrates, with different gain layer doping profiles and thicknesses (45, 50 and 80 μm). Their performance in terms of gain/collected charge and leakage current was compared before and after irradiation with neutrons and pions up to the equivalent fluences of 5 ṡ 1015 cm-2. Transient Current Technique and charge collection measurements with LHC speed electronics were employed to characterize the detectors. The thin LGAD sensors were shown to perform much better than sensors of standard thickness (∼300 μm) and offer larger charge collection with respect to detectors without gain layer for fluences gain prolongs the beneficial performance of LGADs. Pions were found to be more damaging than neutrons at the same equivalent fluence, while no significant difference was found between different producers. At very high fluences and bias voltages the gain appears due to deep acceptors in the bulk, hence also in thin standard detectors.

Characterization of Thin Pixel Sensor Modules Interconnected with SLID Technology Irradiated to a Fluence of 2⋅10 15 $n_{eq}$ /cm 2

CERN Document Server

Weigell, P; Beimforde, M; Macchiolo, A; Moser, H G; Nisius, R; Richter, R H

2011-01-01

A new module concept for future ATLAS pixel detector upgrades is presented, where thin n-in-p silicon sensors are connected to the front-end chip exploiting the novel Solid Liquid Interdiffusion technique (SLID) and the signals are read out via Inter Chip Vias (ICV) etched through the front-end. This should serve as a proof of principle for future four-side buttable pixel assemblies for the ATLAS upgrades, without the cantilever presently needed in the chip for the wire bonding. The SLID interconnection, developed by the Fraunhofer EMFT, is a possible alternative to the standard bump-bonding. It is characterized by a very thin eutectic Cu-Sn alloy and allows for stacking of different layers of chips on top of the first one, without destroying the pre-existing bonds. This paves the way for vertical integration technologies. Results of the characterization of the first pixel modules interconnected through SLID as well as of one sample irradiated to 2⋅10 15 \\,\

Effects of argon flow rate on electrical properties of amorphous indium gallium zinc oxide thin-film transistors

Energy Technology Data Exchange (ETDEWEB)

Sahoo, A.K.; Wu, G.M., E-mail: wu@mail.cgu.edu.tw

2016-04-30

In this report, amorphous indium gallium zinc oxide (a-IGZO) thin films were deposited on glass substrates using different argon flow rates (AFRs). The impact on the electrical properties of the a-IGZO thin-film transistors with various AFRs during film growth has been carefully investigated. The AFR varied 20–60 sccm while the oxygen flow rate was maintained at 1 sccm. All a-IGZO films achieved transmittance higher than 80% in the wavelength range of 350–1000 nm, and it increased slightly with increasing AFR in the higher wavelength region. The rise in partial pressure due to increased AFR could affect the performance, in particular by increasing the current on/off ratio, and changes in electron mobility, sub-threshold swing voltage and threshold voltage. The optimal results were attained at AFR of 50 sccm. The field effect mobility, sub-threshold swing, ratio of on-current to the off-current, interfacial trap density and threshold voltage are 27.7 cm{sup 2}/V·s, 0.11 V/dec, 2.9 × 10{sup 8}, 1.1 × 10{sup 12} cm{sup −2} eV{sup −1} and 0.84 V, respectively. In addition, good electrical properties were achieved using dielectric SiO{sub 2} prepared by simple, low-cost electron beam evaporator system. - Highlights: • IGZO thin films RF-sputtered on glass substrates under various Ar to oxygen flow rates • The electrical performances and thin film quality of a-IGZO TFT were characterized. • High mobility 27.7 cm{sup 2}/V·s and very small sub-threshold voltage 0.11 V/decade obtained. • Simple and low cost electron-beam deposited SiO{sub 2} used as gate dielectric. • Ohmic behavior of source–drain with channel material has been achieved.

Effects of argon flow rate on electrical properties of amorphous indium gallium zinc oxide thin-film transistors

International Nuclear Information System (INIS)

Sahoo, A.K.; Wu, G.M.

2016-01-01

In this report, amorphous indium gallium zinc oxide (a-IGZO) thin films were deposited on glass substrates using different argon flow rates (AFRs). The impact on the electrical properties of the a-IGZO thin-film transistors with various AFRs during film growth has been carefully investigated. The AFR varied 20–60 sccm while the oxygen flow rate was maintained at 1 sccm. All a-IGZO films achieved transmittance higher than 80% in the wavelength range of 350–1000 nm, and it increased slightly with increasing AFR in the higher wavelength region. The rise in partial pressure due to increased AFR could affect the performance, in particular by increasing the current on/off ratio, and changes in electron mobility, sub-threshold swing voltage and threshold voltage. The optimal results were attained at AFR of 50 sccm. The field effect mobility, sub-threshold swing, ratio of on-current to the off-current, interfacial trap density and threshold voltage are 27.7 cm"2/V·s, 0.11 V/dec, 2.9 × 10"8, 1.1 × 10"1"2 cm"−"2 eV"−"1 and 0.84 V, respectively. In addition, good electrical properties were achieved using dielectric SiO_2 prepared by simple, low-cost electron beam evaporator system. - Highlights: • IGZO thin films RF-sputtered on glass substrates under various Ar to oxygen flow rates • The electrical performances and thin film quality of a-IGZO TFT were characterized. • High mobility 27.7 cm"2/V·s and very small sub-threshold voltage 0.11 V/decade obtained. • Simple and low cost electron-beam deposited SiO_2 used as gate dielectric. • Ohmic behavior of source–drain with channel material has been achieved.

In-situ study of pn-heterojunction interface states in organic thin film transistors

Energy Technology Data Exchange (ETDEWEB)

Ye, Rongbin, E-mail: ye@iwate-u.ac.jp; Ohta, Koji; Baba, Mamoru

2014-03-03

In this paper, we have investigated the density of pn-heterojunction interface states by evaluating the threshold voltage shift with in-situ measurement of electrical characteristics of a sandwich fluorinated copper phthalocyanine/pentacene thin film transistor with various thicknesses of pentacene thin films. A threshold voltage (V{sub T}) undergoes a significant shift from + 20.6 to + 0.53 V with increasing the thickness of pentacene. When the thickness of pentacene is more than a critical thickness of 15 nm, V{sub T} undergoes hardly any shift. On the other hand, the value of mobility is lightly decreased with increasing the thickness of pentacene due to the effect of the bulk current. Thus the V{sub T} shift is attributed to the increase of drain current in the sandwich device. In order to explain the V{sub T} shift, a model was assumed in the linear region of thin film transistor operation and the V{sub T} shift agrees with a tan{sup −1} function of film thickness. The total charge density (Q{sub 0}) of 1.53 × 10{sup −7} C/cm{sup 2} (9.56 × 10{sup 11} electrons or holes/cm{sup 2}) was obtained. Furthermore, the V{sub T} shift and Q{sub 0} could be adjusted by selecting a p-type semiconductor. - Highlights: • A threshold voltage was in-situ measured in an organic sandwich thin film transistor. • Density of pn-heterojunction interface states by evaluating the threshold voltage shift. • The threshold voltage shift attributes to the increase of drain current. • In order to explain the threshold voltage shift, a model was assumed.

Determination of diffusion coefficients in Au/Ni thin films by Auger electron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Abdul-Lettif, Ahmed M. [Physics Department, College of Science, Babylon University, Hilla (Iraq)

2004-07-01

Interdiffusion in vacuum-deposited Au/Ni thin films at temperatures in the range 200-500 C has been investigated using the Auger depth profiling technique and X-ray diffraction analysis. A modified Wipple model was used to determine the diffusion coefficients of Ni in Au to be 5.3 x 10{sup -16} cm{sup 2}/s at 500 C, 4.0 x 10{sup -17} cm{sup 2}/s at 400 C, 2.5 x 10{sup -18} cm{sup 2}/s at 300 C, and 1.2 x 10{sup -19} cm{sup 2}/s at 200 C. An activation energy of 0.87 eV was calculated. The present diffusion data differ significantly from the corresponding values extracted by some other investigators and the reasons for this disagreement were discussed. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

High-mobility pyrene-based semiconductor for organic thin-film transistors.

Science.gov (United States)

Cho, Hyunduck; Lee, Sunyoung; Cho, Nam Sung; Jabbour, Ghassan E; Kwak, Jeonghun; Hwang, Do-Hoon; Lee, Changhee

2013-05-01

Numerous conjugated oligoacenes and polythiophenes are being heavily studied in the search for high-mobility organic semiconductors. Although many researchers have designed fused aromatic compounds as organic semiconductors for organic thin-film transistors (OTFTs), pyrene-based organic semiconductors with high mobilities and on-off current ratios have not yet been reported. Here, we introduce a new pyrene-based p-type organic semiconductor showing liquid crystal behavior. The thin film characteristics of this material are investigated by varying the substrate temperature during the deposition and the gate dielectric condition using the surface modification with a self-assembled monolayer, and systematically studied in correlation with the performances of transistor devices with this compound. OTFT fabricated under the optimum deposition conditions of this compound, namely, 1,6-bis(5'-octyl-2,2'-bithiophen-5-yl)pyrene (BOBTP) shows a high-performance transistor behavior with a field-effect mobility of 2.1 cm(2) V(-1) s(-1) and an on-off current ratio of 7.6 × 10(6) and enhanced long-term stability compared to the pentacene thin-film transistor.

Hole-vibrational coupling in Pentacene thin films detected by UPS

International Nuclear Information System (INIS)

Yamame, H.; Fukagawa, H.; Honda, H.; Ono, M.; Okudaira, K.K.; Ueno, N.; Kera, S.; Ishii, H.

2004-01-01

Full text:The hole/electron-vibrational coupling plays a crucial rule in the hole/electron transport in organic devices. In this work, fine structure of the highest occupied molecular orbital (HOMO) band in oriented thin films of pentacene on graphite (HOPG) was studied by using high-resolution ultraviolet photoelectron spectroscopy (UPS). Figure 1 shows the comparison of UPS spectra between pentacene thin films (circles) and gas-phase pentacene (dashed line). We observed a very sharp HOMO band, which consists of at least three components, as observed for Cu-phthalocyanine monolayer on HOPG. It is of note that the relative intensities of fine structures are different between the condensed phase and gas phase, while their energy separations are the same for the two phases (∼ 0.17 eV / 1400 cm -1 ). Furthermore, the relative intensity of fine structures showed remarkable dependence on photoelectron-take-off angle. Judging from these results, the observed fine structures in UPS originate from the hole-vibrational (molecular C-C stretching) coupling in pentacene thin films. At the conference, temperature and thickness dependences of UPS will be discussed

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.

Selective metallization of amorphous-indium-gallium-zinc-oxide thin-film transistor by using helium plasma treatment

Science.gov (United States)

Jang, Hun; Lee, Su Jeong; Porte, Yoann; Myoung, Jae-Min

2018-03-01

In this study, the effects of helium (He) plasma treatment on amorphous-indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs) have been investigated. The He plasma treatment induced a dramatic decrease of the resistivity in a-IGZO thin films from 1.25 × 106 to 5.93 mΩ cm. After 5 min He plasma treatment, the a-IGZO films showed an increase in carrier concentration to 6.70 × 1019 cm-3 combined with a high hall mobility of 15.7 cm2 V-1 s-1. The conductivity improvement was linked to the formation of oxygen vacancies during the He plasma treatment, which was observed by x-ray photoelectron spectroscopy analysis. The a-IGZO films did not appear to be damaged on the surface following the plasma treatment and showed a high transmittance of about 88.3% at a wavelength of 550 nm. The He plasma-treated a-IGZO films were used as source/drain (S/D) electrodes in a-IGZO TFTs. The devices demonstrated promising characteristics, on pair with TFTs using Al electrodes, with a threshold voltage (V T) of -1.97 V, sub-threshold slope (SS) of 0.52 V/decade, saturation mobility (μ sat) of 8.75 cm2 V-1 s-1, and on/off current ratio (I on/I off) of 2.66 × 108.

Crystallization of Electrodeposited Germanium Thin Film on Silicon (100).

Science.gov (United States)

Abidin, Mastura Shafinaz Zainal; Matsumura, Ryo; Anisuzzaman, Mohammad; Park, Jong-Hyeok; Muta, Shunpei; Mahmood, Mohamad Rusop; Sadoh, Taizoh; Hashim, Abdul Manaf

2013-11-06

We report the crystallization of electrodeposited germanium (Ge) thin films on n-silicon (Si) (100) by rapid melting process. The electrodeposition was carried out in germanium (IV) chloride: propylene glycol (GeCl₄:C₃H₈O₂) electrolyte with constant current of 50 mA for 30 min. The measured Raman spectra and electron backscattering diffraction (EBSD) images show that the as-deposited Ge thin film was amorphous. The crystallization of deposited Ge was achieved by rapid thermal annealing (RTA) at 980 °C for 1 s. The EBSD images confirm that the orientations of the annealed Ge are similar to that of the Si substrate. The highly intense peak of Raman spectra at 300 cm -1 corresponding to Ge-Ge vibration mode was observed, indicating good crystal quality of Ge. An additional sub peak near to 390 cm -1 corresponding to the Si-Ge vibration mode was also observed, indicating the Ge-Si mixing at Ge/Si interface. Auger electron spectroscopy (AES) reveals that the intermixing depth was around 60 nm. The calculated Si fraction from Raman spectra was found to be in good agreement with the value estimated from Ge-Si equilibrium phase diagram. The proposed technique is expected to be an effective way to crystallize Ge films for various device applications as well as to create strain at the Ge-Si interface for enhancement of mobility.

Improving the performance of organic thin film transistors formed on a vacuum flash-evaporated acrylate insulator

Energy Technology Data Exchange (ETDEWEB)

Ding, Z., E-mail: ziqian.ding@materials.ox.ac.uk; Abbas, G. A.; Assender, H. E. [Department of Materials, University of Oxford, Oxford OX1 3PH (United Kingdom); Morrison, J. J.; Sanchez-Romaguera, V.; Yeates, S. G. [School of Chemistry, University of Manchester, Manchester M13 9PL (United Kingdom); Taylor, D. M. [School of Electronic Engineering, Bangor University, Bangor LL57 1UT (United Kingdom)

2013-12-02

A systematic investigation has been undertaken, in which thin polymer buffer layers with different ester content have been spin-coated onto a flash-evaporated, cross-linked diacrylate gate-insulator to form bottom-gate, top-contact organic thin-film transistors. The highest device mobilities, ∼0.65 cm{sup 2}/V s and ∼1.00 cm{sup 2}/V s for pentacene and dinaphtho[2,3-b:2′,3′-f]-thieno[3,2-b]thiophene (DNTT), respectively, were only observed for a combination of large-grain (∼1–2 μm) semiconductor morphology coupled with a non-polar dielectric surface. No correlation was found between semiconductor grain size and dielectric surface chemistry. The threshold voltage of pentacene devices shifted from −10 V to −25 V with decreasing surface ester content, but remained close to 0 V for DNTT.

Characterizing transport current defects in 1-cm-wide YBa[sub 2]Cu[sub 3]O[sub 7-delta] coated conductors.

Energy Technology Data Exchange (ETDEWEB)

Brown, G. W. (Geoffrey W.); Hawley, M. E. (Marilyn E.); Peterson, E. J. (Eric J.); Coulter, J. Y. (James Y.); Dowden, P. C. (Paul C.); Arendt, P. N. (Paul N.); Foltyn, S. R. (Stephen R.); Mueller, F. M. (Fred M.)

2001-01-01

We have used a low temperature magnetic imaging system to determine current pathways in 5 cm long 'good' and 'bad' regions of a 1-cm-wide YBa2Cu3O7-{delta} coated conductor. The good and bad regions were identified with 4 point probe measurements taken at 1 cm intervals along the tape length. The current density map from the good region showed the expected edge peaked structure, similar to that seen in previous work on high quality test samples grown on single crystal substrates. The structure was also consistent with theoretical understanding of thin film superconductors where demagnetizing effects are strong. The maps from the bad region showed that the current was primarily confined to the right half of the sample. The left half carried only a small current that reached saturation quickly. Effectively halving the sample width quantitatively explains the critical current measured in that section. Spatially resolved xray analysis with 1 mm resolution was used to further characterize the bad section and suggested an abnormally large amount of a-axis YBCO present. This may be the result of non-uniform heating leading to a low deposition temperature in that area.

Morphological and optical properties of silicon thin films by PLD

International Nuclear Information System (INIS)

Ayouchi, R.; Schwarz, R.; Melo, L.V.; Ramalho, R.; Alves, E.; Marques, C.P.; Santos, L.; Almeida, R.; Conde, O.

2009-01-01

Silicon thin films have been prepared on sapphire substrates by pulsed laser deposition (PLD) technique. The films were deposited in vacuum from a silicon target at a base pressure of 10 -6 mbar in the temperature range from 400 to 800 deg. C. A Q-switched Nd:YAG laser (1064 nm, 5 ns duration, 10 Hz) at a constant energy density of 2 J x cm -2 has been used. The influence of the substrate temperature on the structural, morphological and optical properties of the Si thin films was investigated. Spectral ellipsometry and atomic force microscopy (AFM) were used to study the thickness and the surface roughness of the deposited films. Surface roughness values measured by AFM and ellipsometry show the same tendency of increasing roughness with increased deposition temperature

Pulsed Laser Annealing of Thin Films of Self-Assembled Nanocrystals

KAUST Repository

Baumgardner, William J.

2011-09-27

We investigated how pulsed laser annealing can be applied to process thin films of colloidal nanocrystals (NCs) into interconnected nanostructures. We illustrate the relationship between incident laser fluence and changes in morphology of PbSe NC films relative to bulk-like PbSe films. We found that laser pulse fluences in the range of 30 to 200 mJ/cm2 create a processing window of opportunity where the NC film morphology goes through interesting transformations without large-scale coalescence of the NCs. NC coalescence can be mitigated by depositing a thin film of amorphous silicon (a-Si) on the NC film. Remarkably, pulsed laser annealing of the a-Si/PbSe NC films crystallized the silicon while NC morphology and translational order of the NC film are preserved. © 2011 American Chemical Society.

Swift heavy ions induced material reorganization on surface of barium fluoride thin films

International Nuclear Information System (INIS)

Pandey, Ratnesh K.; Kumar, Manvendra; Pandey, Avinash C.; Khan, Saif A.; Singh, Udai B.; Tripathi, Ambuj; Avasthi, D.K.

2014-01-01

Swift heavy ions induced thermal spike is found to result in a highly excited nanometric cylindrical zone in insulating materials. The resulting transient local melting (taking place on ps timescale) results in formation of a defect-rich or amorphous latent track. In the present work we are reporting evolution of lamellae structure on surface of BaF_2 thin films due to irradiation with 100 MeV Au"+"8 ions. These thin films of BaF_2 have been deposited on glass substrate using electron beam evaporation method and have a thickness of 200 nm. Irradiation was performed at liquid nitrogen temperature and at an angle of incidence of 15° shows the scanning electron microscopic (SEM) images of evolution of lamellae pattern. A cracking perpendicular to the beam direction at low fluences of 5x10"1"2 ions/cm"2 is observed, while at higher fluences of 2x10"1"3 ions/cm"2, the material started to shrink. After application of further high fluences up to 2x10"1"4 ions/cm"2, the BaF_2 layer was reorganized in form of lamellae having orientation as found for the cracks and normal to the beam direction. A self-organized phenomenon in SHI irradiated NiO layers, resulting in formation of 100-nm-thick and 1-µm-high NiO lamellae has also been observed. (author)

Solid-State Densification of Spun-Cast Self-Assembled Monolayers for Use in Ultra-Thin Hybrid Dielectrics.

Science.gov (United States)

Hutchins, Daniel O; Acton, Orb; Weidner, Tobias; Cernetic, Nathan; Baio, Joe E; Castner, David G; Ma, Hong; Jen, Alex K-Y

2012-11-15

Ultra-thin self-assembled monolayer (SAM)-oxide hybrid dielectrics have gained significant interest for their application in low-voltage organic thin film transistors (OTFTs). A [8-(11-phenoxy-undecyloxy)-octyl]phosphonic acid (PhO-19-PA) SAM on ultrathin AlO x (2.5 nm) has been developed to significantly enhance the dielectric performance of inorganic oxides through reduction of leakage current while maintaining similar capacitance to the underlying oxide structure. Rapid processing of this SAM in ambient conditions is achieved by spin coating, however, as-cast monolayer density is not sufficient for dielectric applications. Thermal annealing of a bulk spun-cast PhO-19-PA molecular film is explored as a mechanism for SAM densification. SAM density, or surface coverage, and order are examined as a function of annealing temperature. These SAM characteristics are probed through atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and near edge X-ray absorption fine structure spectroscopy (NEXAFS). It is found that at temperatures sufficient to melt the as-cast bulk molecular film, SAM densification is achieved; leading to a rapid processing technique for high performance SAM-oxide hybrid dielectric systems utilizing a single wet processing step. To demonstrate low-voltage devices based on this hybrid dielectric (with leakage current density of 7.7×10 -8 A cm -2 and capacitance density of 0.62 µF cm -2 at 3 V), pentacene thin-film transistors (OTFTs) are fabricated and yield sub 2 V operation and charge carrier mobilites of up to 1.1 cm 2 V -1 s -1 .

Petrologic evolution of CM chondrites: The difficulty of discriminating between nebular and parent-body effects

Science.gov (United States)

Kerridge, J. F.; McSween, H. Y., Jr.; Bunch, T. E.

1994-07-01

We wish to draw attention to a major controversy that has arisen in the area of CM-chondrite petrology. The problem is important because its resolution will have profound implications for ideas concerning nebular dynamics, gas-solid interactions in the nebula, and accretionary processes in the nebula, among other issues. On the one hand, cogent arguments have been presented that 'accretionary dust mantles,' were formed in the solar nebula prior to accretion of the CM parent asteroid(s). On the other hand, no-less-powerful arguments have been advanced that a significant fraction of the CM lithology is secondary, produced by aqueous alteration in the near-surface regions of an asteroid-sized object. Because most, if not all, CM chondrites are breccias, these two views could coexist harmoniously, were it not for the fact that some of the coarse-grained lithologies surrounded by 'accretion dust mantles' are themselves of apparently secondary origin. Such an observation must clearly force a reassessment of one or both of the present schools of thought. Our objective here is to stimulate such a reassessment. Four possible resolutions of this conflict may be postulated. First, perhaps nature found a way of permitting such secondary alteration to take place in the nebula. Second, maybe dust mantles could form in a regolith, rather than a nebular, environment. Third, it is possible that dust mantles around secondary lithologies are different from those around primary lithologies. Finally, perhaps formation of CM chondrites involved a more complex sequence of events than visualized so far, so that some apparently 'primary' processes postdated certain 'secondary' processes.

Basic characteristics of thin wire arc plasma

International Nuclear Information System (INIS)

Urushihara, K.; Endoh, N.; Ono, S.; Teii, S.; Ishimura, T.

1998-01-01

The investigated plasma was generated by applying an electric current of about 50 A to a copper wire of 48 μm diameter in air. The development in time of emission spectra was measured and relative line intensity ratios were used to determine the temperature. The extension of the plasma was measured with a movable electrostatic probe which was placed next to the thin wire, and the electron density was estimated using the known electron mobility. The electron temperature was typically about 8000 K. On the other hand, the electron density tended to decrease with time from about 3.10 16 cm -3

Associations of geomagnetic activity with plasma sheet thinning and expansion: A statistical study

International Nuclear Information System (INIS)

Hones, E.W. Jr.; Pytte, T.; West, H.I. Jr.

1984-01-01

Associations of geomagnetic activity in the auroral zone with thinnings and expansions of the magnetotail plasma sheet are examined statistically in this paper. We first identified many plasma sheet thinnings and expansions in plasma and particle data from VELA satellites and from OGO 5 without reference to the ground magnetic data. These events were grouped according to the location of the detecting satellite in the magnetotail. For each such group the times of thinning or expansion were then used as fiducial times in a superposed-epoch analysis of the geomagnetic AL index values that were recorded in 8-hour intervals centered on the event times. The results show that many plasma sheet thinnings and expansions are related to discrete negative bay structures that are the classical signature of substorms. Furthermore, they support earlier findings that plasma sheet thinning and expansion at the VELA orbit (rroughly-equal18 R/sub E/) tend to be associated with the onset of the auroral zone negative bay and the beginning of its subsidence, respectively. Earthward of rroughly-equal13-15 R/sub E/, plasma sheet expansion occurs near the time of the onset of the negative bay, again in agreement with earlier findings. A large fraction of plasma sheet expansions to half thicknesses of > or approx. =6 R/sub E/ at the VELA orbit are associated not with a baylike geomagnetic disturbance but with subsidence of a prolonged interval of disturbance. The study also shows that many plasma sheet expansions are related simply to generally enhanced geomagnetic activity showing no baylike or other distinctive features

Synthesis and characterization of lead sulphide thin films from ethanolamine (ETA) complexing agent chemical bath

Science.gov (United States)

Gashaw Hone, Fekadu; Dejene, F. B.

2018-02-01

Polycrystalline lead sulphide (PbS) thin films were grown on glass substrates by chemical bath deposition route using ethanolamine (ETA) as a complexing agent. The effects of ETA molar concentration on the structural, morphological, electrical and optical properties of lead sulphide thin films were thoroughly studied. The XRD analyses revealed that all the deposited thin films were face center cubic crystal structure and their preferred orientations were varied along the (111) and (200) planes. The XRD results further confirmed that ETA concentration had a significant effects on the strain, average crystalline size and dislocation density of the deposited thin films. The SEM studies illustrated the evolution and transformation of surface morphology as ETA molar concentration increased from 0.41 M to 1.64 M. The energy dispersive x-ray analysis was used to verify the compositional elements of the deposited thin films. Optical spectroscopy investigation established that the band gap of the PbS thin films were reduced from 0.98 eV to 0.68 eV as ETA concentration increased. The photoluminescence spectra showed a well defined peak at 428 nm and shoulder around 468 nm for all PbS thin films. The electrical resistivity of the thin films found in the order of 103 Ω cm at room temperature and decreased as the ETA molar concentration was increased.

Growth and characterization of tin oxide thin films and fabrication of transparent p-SnO/n-ZnO p–n hetero junction

Energy Technology Data Exchange (ETDEWEB)

Sanal, K.C., E-mail: sanalcusat@gmail.com [Nanophotonic and Optoelectronic Devices Laboratory, Department of Physics, Cochin University of Science and Technology, Kerala 682 022 (India); Inter University Center for Nanomaterials and Devices (IUCND), Cochin University of Science and Technology (India); Jayaraj, M.K. [Nanophotonic and Optoelectronic Devices Laboratory, Department of Physics, Cochin University of Science and Technology, Kerala 682 022 (India)

2013-07-01

Highlights: • Growth of p-type semiconducting SnO thin films by rf sputtering. • Varying the type of charge carriers with oxygen partial pressure. • Atomic percentage of SnO{sub x} thin films from the XPS analysis. • Demonstration of transparent p–n hetero junctions fabricated in the structure glass/ITO/n-ZnO/p-SnO. -- Abstract: p-Type and n-type tin oxide thin films were deposited by rf-magnetron sputtering of metal tin target by varying the oxygen pressure. Chemical composition of SnO thin film according to the intensity of the XPS peak is about 48.85% and 51.15% for tin and oxygen respectively. Nearest neighbor distance of the atoms calculated from SAED patterns is 2.9 Åand 2.7 Åfor SnO and SnO{sub 2} respectively. The Raman scattering spectrum obtained from SnO thin films showed two peaks, one at 113 cm{sup −1} and the other at 211 cm{sup −1}. Band gap of as-deposited SnO{sub x} thin films vary from 1.6 eV to 3.2 eV on varying the oxygen partial pressure from 3% to 30% which indicates the oxidization of metallic phase Sn to SnO and SnO{sub 2}. p-Type conductivity of SnO thin films and n-type conductivity of SnO{sub 2} thin films were confirmed through Hall coefficient measurement. Transparent p–n hetero junction fabricated in the structure glass/ITO/n-ZnO/p-SnO shows rectification with forward to reverse current ratio as 12 at 4.5 V.

Optical and electrical properties of transparent conductive ITO thin films under proton radiation with 100 keV

International Nuclear Information System (INIS)

Wei, Q.; He, S.Y.; Yang, D.Z.; Liu, J.C.

2005-01-01

Under the simulation environment for the vacuum and heat sink in space, the changes in optical and electrical properties of transparent conductive indium tin oxide (ITO) thin films induced by radiation of protons with 100 keV were studied. The ITO thin films were deposited on JGS1 quartz substrate by a sol-gel method. The sheet resistance and transmittance spectra of the ITO thin films were measured using the four-point probe method and a spectrophotometer, respectively. The surface morphology was analyzed by AFM. The experimental results showed that the electrical and optical performances of the ITO thin films were closely related to the irradiation fluence. When the fluence exceeded a given value 2 x 10 16 cm -2 , the sheet resistance increased obviously and the optical transmittance decreased. The AFM analysis indicated that the grain size of the ITO thin films diminished. The studies about the radiation effect on ITO thin films will help to predict performance evolution of the second surface mirrors on satellites under space radiation environment. (orig.)

2-cm versus 4-cm surgical excision margins for primary cutaneous melanoma thicker than 2 mm: a randomised, multicentre trial

DEFF Research Database (Denmark)

Gillgren, Peter; Drzewiecki, Krzysztof T; Niin, Marianne

2011-01-01

Optimum surgical resection margins for patients with clinical stage IIA-C cutaneous melanoma thicker than 2 mm are controversial. The aim of the study was to test whether survival was different for a wide local excision margin of 2 cm compared with a 4-cm excision margin.......Optimum surgical resection margins for patients with clinical stage IIA-C cutaneous melanoma thicker than 2 mm are controversial. The aim of the study was to test whether survival was different for a wide local excision margin of 2 cm compared with a 4-cm excision margin....

Thermal stability of pulsed laser deposited iridium oxide thin films at low oxygen atmosphere

Science.gov (United States)

Gong, Yansheng; Wang, Chuanbin; Shen, Qiang; Zhang, Lianmeng

2013-11-01

Iridium oxide (IrO2) thin films have been regarded as a leading candidate for bottom electrode and diffusion barrier of ferroelectric capacitors, some process related issues need to be considered before integrating ferroelectric capacitors into memory cells. This paper presents the thermal stability of pulsed laser deposited IrO2 thin films at low oxygen atmosphere. Emphasis was given on the effect of post-deposition annealing temperature at different oxygen pressure (PO2) on the crystal structure, surface morphology, electrical resistivity, carrier concentration and mobility of IrO2 thin films. The results showed that the thermal stability of IrO2 thin films was strongly dependent on the oxygen pressure and annealing temperature. IrO2 thin films can stably exist below 923 K at PO2 = 1 Pa, which had a higher stability than the previous reported results. The surface morphology of IrO2 thin films depended on PO2 and annealing temperature, showing a flat and uniform surface for the annealed films. Electrical properties were found to be sensitive to both the annealing temperature and oxygen pressure. The room-temperature resistivity of IrO2 thin films with a value of 49-58 μΩ cm increased with annealing temperature at PO2 = 1 Pa. The thermal stability of IrO2 thin films as a function of oxygen pressure and annealing temperature was almost consistent with thermodynamic calculation.

DESIGN OF A THIN QUADRUPOLE TO BE USED IN THE AGS SYNCHROTRON

Energy Technology Data Exchange (ETDEWEB)

TSOUPAS,N.; AHRENS, L.; ALFORQUE, R.; BAI, M.; BROWN, K.; COURANT, E.; ET AL.

2007-06-25

The Alternating Gradient Synchrotron (AGS) employs two partial helical snakes[l] to preserve the polarization of the proton beam during acceleration. In order to compensate for the focusing effect of the partial helical snakes on the beam optics in the AGS during acceleration of the beam, we introduced eight quadrupoles in straight sections of the AGS at the proximity of the partial snakes. At injection energies, the strength of each quad is set at a high value, and is ramped down to zero as the effect of the snakes diminishes by the square of beam's rigidity. Four of the eight compensation quadrupoles had to be placed in very short straight sections -30 cm in length, therefore the quadruples had be thin with an overall length of less than 30 cm. In this paper we will discus: (a) the mechanical and magnetic specifications of the ''thin'' quadrupole. (b) the method to minimize the strength of the dodecapole harmonic, (c) the method to optimize the thickness of the laminations that the magnet iron is made, (d) mechanical tolerances of the magnet, (e) comparison of the measured and calculated magnetic multipoles of the quadrupole.

Benzothienobenzothiophene-based conjugated oligomers as semiconductors for stable organic thin-film transistors.

Science.gov (United States)

Yu, Han; Li, Weili; Tian, Hongkun; Wang, Haibo; Yan, Donghang; Zhang, Jingping; Geng, Yanhou; Wang, Fosong

2014-04-09

Two benzothienobenzothiophene (BTBT)-based conjugated oligomers, i.e., 2,2'-bi[1]benzothieno[3,2-b][1]benzothiophene (1) and 5,5'-bis([1]benzothieno[3,2-b][1]benzothiophen-2-yl)-2,2'-bithiophene (2), were prepared and characterized. Both oligomers exhibit excellent thermal stability, with 5% weight-loss temperatures (T(L)) above 370 °C; no phase transition was observed before decomposition. The highest occupied molecular orbital (HOMO) levels of 1 and 2 are -5.3 and -4.9 eV, respectively, as measured by ultraviolet photoelectron spectroscopy. Thin-film X-ray diffraction and atomic force microscopy characterizations indicate that both oligomers form highly crystalline films with large domain sizes on octadecyltrimethoxysilane-modified substrates. Organic thin-film transistors with top-contact and bottom-gate geometry based on 1 and 2 exhibited mobilities up to 2.12 cm(2)/V·s for 1 and 1.39 cm(2)/V·s for 2 in an ambient atmosphere. 1-based devices exhibited great air and thermal stabilities, as evidenced by the slight performance degradation after 2 months of storage under ambient conditions and after thermal annealing at temperatures below 250 °C.

Preparation of thin-film (Ba(0.5),Sr(0.5))TiO3 by the laser ablation technique and electrical properties

Science.gov (United States)

Yoon, Soon-Gil; Lee, Jai-Chan; Safari, A.

1994-09-01

The chemical composition and electrical properties were investigated for epitaxially crystallized (Ba(0.5),Sr(0.5))TiO3 (BST) films deposited on Pt/MgO and YBa2Cu3O(7-x) (YBCO)/MgO substrates by the laser ablation technique. Rutherford backscattering spectroscopy analysis shows that thin films on Pt/MgO have almost the same stoichiometric composition as the target material. Films deposited at 600 C exhibited an excellent epitaxial growth, a dielectric constant of 430, and a dissipation factor of 0.02 at 10 kHz frequency. They have a charge storage density of 40 fC/sq micron at an applied electric field of 0.15 MV/cm. Leakage current density of BST thin films on Pt/MgO was smaller than on YBCO/MgO. Their leakage current density is about 0.8 microA/sq cm at an applied electric field of 0.15 MV/cm.

TiO2 and Cu/TiO2 Thin Films Prepared by SPT

Directory of Open Access Journals (Sweden)

S. S. Roy

2015-12-01

Full Text Available Titanium oxide (TiO2 and copper (Cu doped titanium oxide (Cu/TiO2 thin films have been prepared by spray pyrolysis technique. Titanium chloride (TiCl4 and copper acetate (Cu(CH3COO2.H2O were used as source of Ti and Cu. The doping concentration of Cu was varied from 1-10 wt. %. The X-ray diffraction studies show that TiO2 thin films are tetragonal structure and Cu/TiO2 thin films implies CuO has present with monoclinic structure. The optical properties of the TiO2 thin films have been investigated as a function of Cu-doping level. The optical transmission of the thin films was found to increase from 88 % to 94 % with the addition of Cu up to 8 % and then decreases for higher percentage of Cu doping. The optical band gap (Eg for pure TiO2 thin film is found to be 3.40 eV. Due to Cu doping, the band gap is shifted to lower energies and then increases further with increasing the concentration of Cu. The refractive index of the TiO2 thin films is found to be 2.58 and the variation of refractive index is observed due to Cu doped. The room temperature resistivity of the films decreases with increasing Cu doping and is found to be 27.50 - 23.76 W·cm. It is evident from the present study that the Cu doping promoted the thin film morphology and thereby it is aspect for various applications.

Optical and electrical properties of zinc oxide thin films with low resistivity via Li-N dual-acceptor doping

Energy Technology Data Exchange (ETDEWEB)

Zhang Daoli, E-mail: zhang_daoli@mail.hust.edu.cn [Department of Electronic Science and Technology, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Hongshan District, Wuhan City, Hubei Province 430074 (China); Wuhan National Laboratory for Optoelectronics, 1037 Luoyu Road, Hongshan District, Wuhan City, Hubei Province 430074 (China); Zhang Jianbing [Department of Electronic Science and Technology, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Hongshan District, Wuhan City, Hubei Province 430074 (China); Wuhan National Laboratory for Optoelectronics, 1037 Luoyu Road, Hongshan District, Wuhan City, Hubei Province 430074 (China); Guo Zhe [Department of Electronic Science and Technology, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Hongshan District, Wuhan City, Hubei Province 430074 (China); Miao Xiangshui [Department of Electronic Science and Technology, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Hongshan District, Wuhan City, Hubei Province 430074 (China); Wuhan National Laboratory for Optoelectronics, 1037 Luoyu Road, Hongshan District, Wuhan City, Hubei Province 430074 (China)

2011-05-19

Highlights: > Zinc oxide films have been deposited on glass substrates by Li-N dual-acceptor doping method via a modified SILAR method. > The resistivity of ZnO film was found to be 1.04 {Omega} cm with a Hall mobility of 0.749 cm{sup 2} V{sup -1} s{sup -1}, carrier concentration of 8.02 x 1018 cm{sup -3}, and transmittance of about 80% in visible range showing good crystallinity with prior c-axis orientation. > A shallow acceptor level of 91 meV is identified from free-to-neutral-acceptor transitions. > Another deep level of 255 meV was ascribed to Li{sub Zn}-Li{sub i} complex. - Abstract: Zinc oxide thin films with low resistivity have been deposited on glass substrates by Li-N dual-acceptor doping method via a modified successive ionic layer adsorption and reaction process. The thin films were systematically characterized via scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction, ultraviolet-visible spectrophotometry and fluorescence spectrophotometry. The resistivity of zinc oxide film was found to be 1.04 {Omega} cm with a Hall mobility of 0.749 cm{sup 2} V{sup -1} s{sup -1} and carrier concentration of 8.02 x 10{sup 18} cm{sup -3}. The Li-N dual-acceptor doped zinc oxide films showed good crystallinity with prior c-axis orientation, and high transmittance of about 80% in visible range. Moreover, the effects of Li doping level and other parameters on crystallinity, electrical and ultraviolet emission of zinc oxide films were investigated.

Synthesis of Cu2ZnSnS4 thin films by a precursor solution paste for thin film solar cell applications.

Science.gov (United States)

Cho, Jin Woo; Ismail, Agus; Park, Se Jin; Kim, Woong; Yoon, Sungho; Min, Byoung Koun

2013-05-22

Cu2ZnSnS4 (CZTS) is a very promising semiconductor material when used for the absorber layer of thin film solar cells because it consists of only abundant and inexpensive elements. In addition, a low-cost solution process is applicable to the preparation of CZTS absorber films, which reduces the cost when this film is used for the production of thin film solar cells. To fabricate solution-processed CZTS thin film using an easily scalable and relatively safe method, we suggest a precursor solution paste coating method with a two-step heating process (oxidation and sulfurization). The synthesized CZTS film was observed to be composed of grains of a size of ~300 nm, showing an overall densely packed morphology with some pores and voids. A solar cell device with this film as an absorber layer showed the highest efficiency of 3.02% with an open circuit voltage of 556 mV, a short current density of 13.5 mA/cm(2), and a fill factor of 40.3%. We also noted the existence of Cd moieties and an inhomogeneous Zn distribution in the CZTS film, which may have been triggered by the presence of pores and voids in the CZTS film.

Stability of the Regular Hayward Thin-Shell Wormholes

Directory of Open Access Journals (Sweden)

M. Sharif

2016-01-01

Full Text Available The aim of this paper is to construct regular Hayward thin-shell wormholes and analyze their stability. We adopt Israel formalism to calculate surface stresses of the shell and check the null and weak energy conditions for the constructed wormholes. It is found that the stress-energy tensor components violate the null and weak energy conditions leading to the presence of exotic matter at the throat. We analyze the attractive and repulsive characteristics of wormholes corresponding to ar>0 and ar<0, respectively. We also explore stability conditions for the existence of traversable thin-shell wormholes with arbitrarily small amount of fluid describing cosmic expansion. We find that the space-time has nonphysical regions which give rise to event horizon for 0thin-shell wormholes.

Water-soluble polyelectrolyte-grafted multiwalled carbon nanotube thin films for efficient counter electrode of dye-sensitized solar cells.

Science.gov (United States)

Han, Jinkyu; Kim, Hyunju; Kim, Dong Young; Jo, Seong Mu; Jang, Sung-Yeon

2010-06-22

Water-soluble, polyelectrolyte-grafted multiwalled carbon nanotubes (MWCNTs), MWCNT-g-PSSNa, were synthesized using a "grafting to" route. MWCNT-g-PSSNa thin films fabricated by an electrostatic spray (e-spray) technique were used as the counter electrode (CE) for dye-sensitized solar cells (DSSCs). The e-sprayed MWCNT-g-PSSNa thin-film-based CEs (MWCNT-CE) were uniform over a large area, and the well-exfoliated MWCNTs formed highly interconnected network structures. The electrochemical catalytic activity of the MWCNT-CE at different thicknesses was investigated. The MWCNT-g-PSSNa thin film showed high efficiency as a CE in DSSCs. The power conversion efficiency (PCE) of the DSSCs using the MWCNT-g-PSSNa thin-film-based CE (DSSC-MWCNT) was >6% at a CE film thickness of approximately 0.3 microm. The optimum PCE was >7% at a film thickness of approximately 1 microm, which is 20-50 times thinner than conventional carbon-based CE. The charge transfer resistance at the MWCNT-CE/electrolyte interface was 1.52 Omega cm(2) at a MWCNT-CE thickness of 0.31 microm, which is lower than that of a Pt-CE/electrolyte interface, 1.78 Omega cm(2). This highlights the potential for the low-cost CE fabrication of DSSCs using a facile deposition technique from an environmentally "friendly" solution at low temperatures.

Chemically deposited In2S3–Ag2S layers to obtain AgInS2 thin films by thermal annealing

International Nuclear Information System (INIS)

Lugo, S.; Peña, Y.; Calixto-Rodriguez, M.; López-Mata, C.; Ramón, M.L.; Gómez, I.; Acosta, A.

2012-01-01

Highlights: ► We obtained polycrystalline silver indium sulfide thin films through the annealing of chemically deposited In 2 S 3 –Ag 2 S films. ► According to XRD chalcopyrite structure of AgInS 2 was obtained. ► AgInS 2 thin film has a band gap of 1.86 eV and a conductivity value of 1.2 × 10 −3 (Ω cm) −1 . - Abstract: AgInS 2 thin films were obtained by the annealing of chemical bath deposited In 2 S 3 –Ag 2 S layers at 400 °C in N 2 for 1 h. According to the XRD and EDX results the chalcopyrite structure of AgInS 2 has been obtained. These films have an optical band gap, E g , of 1.86 eV and an electrical conductivity value of 1.2 × 10 −3 (Ω cm) −1 .

CuInS{sub 2} thin films obtained through the annealing of chemically deposited In{sub 2}S{sub 3}-CuS thin films

Energy Technology Data Exchange (ETDEWEB)

Pena, Y., E-mail: yolapm@gmail.com [Facultad de Ciencias Quimicas, Universidad Autonoma de Nuevo Leon, Pedro de Alba S/N, Ciudad Universitaria, 66451, San Nicolas de los Garza, Nuevo Leon (Mexico); Lugo, S. [Facultad de Ciencias Quimicas, Universidad Autonoma de Nuevo Leon, Pedro de Alba S/N, Ciudad Universitaria, 66451, San Nicolas de los Garza, Nuevo Leon (Mexico); Calixto-Rodriguez, M. [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico, Privada Xochicalco S/N, Col Centro, 62580, Temixco, Morelos (Mexico); Vazquez, A.; Gomez, I.; Elizondo, P. [Facultad de Ciencias Quimicas, Universidad Autonoma de Nuevo Leon, Pedro de Alba S/N, Ciudad Universitaria, 66451, San Nicolas de los Garza, Nuevo Leon (Mexico)

2011-01-01

In this work, we report the formation of CuInS{sub 2} thin films on glass substrates by heating chemically deposited multilayers of copper sulfide (CuS) and indium sulfide (In{sub 2}S{sub 3}) at 300 and 350 deg. C in nitrogen atmosphere at 10 Torr. CIS thin films were prepared by varying the CuS layer thickness in the multilayers with indium sulfide. The XRD analysis showed that the crystallographic structure of the CuInS{sub 2} (JCPDS 27-0159) is present on the deposited films. From the optical analysis it was estimated the band gap value for the CIS film (1.49 eV). The electrical conductivity varies from 3 x 10{sup -8} to 3 {Omega}{sup -1} cm{sup -1} depending on the thickness of the CuS film. CIS films showed p-type conductivity.

The 10.7-cm microwave observations of AR 5395 and related terrestrial effects

International Nuclear Information System (INIS)

Gaizauskas, V.; Hughes, T.J.; Tapping, K.F.

1989-01-01

The 10.7 cm flux patrols in Canada recorded 4 Great Bursts (peaks greater than 500 sfu) during the disk passage of AR 5395 in March 1989. The Great Bursts of 16 and 17 March were simple events of great amplitude and with half-life durations of only several minutes. Earlier Great Bursts, originating on 6 March towards the NE limb and on 10 March closer to the central meridian, belong to an entirely different category of event. Each started with a very strong impulsive event lasting just minutes. After an initial recovery, however, the emission climbed back to level as greater or greater than the initial impulsive burst. The events of 6 and 10 March stayed above the Great Burst threshold for at least 100 minutes. The second component of long duration in these cases is associated with Type 4 continuum emission and thus very likely with CMEs. Major geomagnetic disturbances did not occur as a result of the massive complex event of 6 March or the two simple but strong events of 16 and 17 March. But some 55 hours after the peak in the long-enduring burst of 10 March, a storm began which qualifies as the fourth strongest geomagnetic storm in Canada since 1932. The vertical component of the earth's field measured during the storm by a fluxgate magnetometer at a station in Manitoba is presented. Within a minute of the sudden commencement of this storm, a series of breakdowns began in the transmission system of Hydro-Quebec which resulted in a total loss of power, on a bitterly cold winter's day, for at least 10 hours. The loss of power provoked an enormous outcry from the public resulting in the power utilities being more receptive to the need to monitor solar as well as geomagnetic activity

Study of working pressure on the optoelectrical properties of Al–Y codoped ZnO thin-film deposited using DC magnetron sputtering for solar cell applications

Energy Technology Data Exchange (ETDEWEB)

Hsu, Feng-Hao [Institute of Microelectronics, Department of Electrical Engineering, National Cheng Kung University, No. 1, Dasyue Road, East District, Tainan City 701, Taiwan (China); Wang, Na-Fu; Tsai, Yu-Zen; Chuang, Ming-Chieh; Cheng, Yu-Song [Department of Electronic Engineering, Cheng Shiu University, 840 Chengcing Road, Niaosong District, Kaohsiung City 833, Taiwan (China); Houng, Mau-Phon, E-mail: mphoung@eembox.ncku.edu.tw [Institute of Microelectronics, Department of Electrical Engineering, National Cheng Kung University, No. 1, Dasyue Road, East District, Tainan City 701, Taiwan (China)

2013-09-01

Low cost transparent conductive Al–Y codoped ZnO (AZOY) thin-films were prepared on a glass substrate using a DC magnetron sputtering technique with various working pressures in the range of 5–13 mTorr. The relationship among the structural, electrical, and optical properties of sputtered AZOY films was studied as a function of working pressure. The XRD measurements show that the crystallinity of the films degraded as the working gas pressure increased. The AZOY thin-film deposited at a working pressure of 5 mTorr exhibited the lowest electrical resistivity of 4.3 × 10{sup −4} Ω cm, carrier mobility of 30 cm{sup 2}/V s, highest carrier concentration of 4.9 × 10{sup 20} cm{sup −3}, and high transmittance in the visible region (400–800 nm) of approximately 90%. Compared with Al doped ZnO (AZO) thin-films deposited using DC or RF magnetron sputtering methods, a high carrier mobility was observed in our AZOY thin-films. This result can be used to effectively decrease the absorption of near infrared-rays in solar cell applications. The mechanisms are attributed to the larger transition energy between Ar atoms and sputtering particles and the size compensation of the dopants. Finally, the optimal quality AZOY thin-film was used as an emitter layer (or window layer) to form AZOY/n-Si heterojunction solar cells, which exhibited a stable conversion efficiency (η) of 9.4% under an AM1.5 illumination condition.

Thinning of young Douglas-fir forests decreases density of northern flying squirrels in the Oregon Cascades

Science.gov (United States)

Manning, Tom; Hagar, Joan C.; McComb, Brenda C.

2012-01-01

Large-scale commercial thinning of young forests in the Pacific Northwest is currently promoted on public lands to accelerate the development of late-seral forest structure for the benefit of wildlife species such as northern spotted owls (Strix occidentalis caurina) and their prey, including the northern flying squirrel (Glaucomys sabrinus). Attempts to measure the impact of commercial thinning on northern flying squirrels have mostly addressed short-term effects (2–5 years post-thinning) and the few published studies of longer-term results have been contradictory. We measured densities of northern flying squirrels 11–13 years after thinning of young (55–65 years) Douglas-fir forest stands in the Cascade Range of Oregon, as part of the Young Stand Thinning & Diversity Study. The study includes four replicate blocks, each consisting of an unthinned control stand and one stand each of the following thinning treatments: Heavy Thin; Light Thin; and Light Thin with Gaps. Thinning decreased density of northern flying squirrels, and squirrel densities were significantly lower in heavily thinned stands than in more lightly thinned stands. Regression analysis revealed a strong positive relationship of flying squirrel density with density of large (>30 cm diameter) standing dead trees and a negative relationship with percent cover of low understory shrubs. Maintaining sufficient area and connectivity of dense, closed canopy forest is recommended as a strategy to assure that long-term goals of promoting late-seral structure do not conflict with short-term habitat requirements of this important species.

High-quality AlGaN/GaN grown on sapphire by gas-source molecular beam epitaxy using a thin low-temperature AlN layer

Energy Technology Data Exchange (ETDEWEB)

Jurkovic, M.J.; Li, L.K.; Turk, B.; Wang, W.I.; Syed, S.; Simonian, D.; Stormer, H.L.

2000-07-01

Growth of high-quality AlGaN/GaN heterostructures on sapphire by ammonia gas-source molecular beam epitaxy is reported. Incorporation of a thin AlN layer grown at low temperature within the GaN buffer is shown to result in enhanced electrical and structural characteristics for subsequently grown heterostructures. AlGaN/GaN structures exhibiting reduced background doping and enhanced Hall mobilities (2100, 10310 and 12200 cm{sup 2}/Vs with carrier sheet densities of 6.1 x 10{sup 12} cm{sup {minus}2}, and 5.8 x 10{sup 12} cm{sup {minus}2} at 300 K, 77 K, and 0.3 K, respectively) correlate with dislocation filtering in the thin AlN layer. Magnetotransport measurements at 0.3 K reveal well-resolved Shubnikov-de Haas oscillations starting at 3 T.

Structural, mechanical and magnetic study on galvanostatic electroplated nanocrystalline NiFeP thin films

Science.gov (United States)

Kalaivani, A.; Senguttuvan, G.; Kannan, R.

2018-03-01

Nickel based alloys has a huge applications in microelectronics and micro electromechanical systems owing to its superior soft magnetic properties. With the advantages of simplicity, cost-effectiveness and controllable patterning, electroplating processes has been chosen to fabricate thin films in our work. The soft magnetic NiFeP thin film was successfully deposited over the surface of copper plate through galvanostatic electroplating method by applying constant current density of 10 mA cm-2 for a deposition rate for half an hour. The properties of the deposited NiFeP thin films were analyzed by subjecting it into different physio-chemical characterization such as XRD, SEM, EDAX, AFM and VSM. XRD pattern confirms the formation of NiFeP particles and the structural analysis reveals that the NiFeP particles were uniformly deposited over the surface of copper substrate. The surface roughness analysis of the NiFeP films was done using AFM analysis. The magnetic studies and the hardness of the thin film were evaluated from the VSM and hardness test. The NiFeP thin films possess lower coercivity with higher magnetization value of 69. 36 × 10-3 and 431.92 Gauss.

An improved thin film brick-wall model of black hole entropy

CERN Document Server

Liu Wen Biao

2001-01-01

The authors improve the brick-wall model to take only the contribution of a thin film near the event horizon into account. This improvement not only gives them a satisfactory result, but also avoids some drawbacks in the original brick-wall method such as the little mass approximation, neglecting logarithm term, and taking the term L/sup 3/ as the contribution of the vacuum surrounding a black hole. It is found that there is an intrinsic relation between the event horizon and the entropy. The event horizon is the characteristic of a black hole, so the entropy calculating of a black hole is also naturally related to its horizon. (12 refs).

MOCVD ZnO/Screen Printed Ag Back Reflector for Flexible Thin Film Silicon Solar Cell Application

Directory of Open Access Journals (Sweden)

Amornrat Limmanee

2014-01-01

Full Text Available We have prepared Ag back electrode by screen printing technique and developed MOCVD ZnO/screen printed Ag back reflector for flexible thin film silicon solar cell application. A discontinuity and poor contact interface between the MOCVD ZnO and screen printed Ag layers caused poor open circuit voltage (Voc and low fill factor (FF; however, an insertion of a thin sputtered ZnO layer at the interface could solve this problem. The n type hydrogenated amorphous silicon (a-Si:H film is preferable for the deposition on the surface of MOCVD ZnO film rather than the microcrystalline film due to its less sensitivity to textured surface, and this allowed an improvement in the FF. The n-i-p flexible amorphous silicon solar cell using the MOCVD ZnO/screen printed Ag back reflector showed an initial efficiency of 6.2% with Voc=0.86 V, Jsc=12.4 mA/cm2, and FF = 0.58 (1 cm2. The identical quantum efficiency and comparable performance to the cells using conventional sputtered Ag back electrode have verified the potential of the MOCVD ZnO/screen printed Ag back reflector and possible opportunity to use the screen printed Ag thick film for flexible thin film silicon solar cells.

Ross Sea Polynyas: Response of Ice Concentration Retrievals to Large Areas of Thin Ice

Science.gov (United States)

Kwok, R.; Comiso, J. C.; Martin, S.; Drucker, R.

2007-01-01

For a 3-month period between May and July of 2005, we examine the response of the Advanced Microwave Scanning Radiometer (AMSR-E) Enhanced NASA Team 2 (NT2) and AMSR-E Bootstrap (ABA) ice concentration algorithms to large areas of thin ice of the Ross Sea polynyas. Coincident Envisat Synthetic Aperture Radar (SAR) coverage of the region during this period offers a detailed look at the development of the polynyas within several hundred kilometers of the ice front. The high-resolution imagery and derived ice motion fields show bands of polynya ice, covering up to approximately 105 km(sup 2) of the Ross Sea, that are associated with wind-forced advection. In this study, ice thickness from AMSR-E 36 GHz polarization information serves as the basis for examination of the response. The quality of the thickness of newly formed sea ice (<10 cm) from AMSR-E is first assessed with thickness estimates derived from ice surface temperatures from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument. The effect of large areas of thin ice in lowering the ice concentration estimates from both NT2/ABA approaches is clearly demonstrated. Results show relatively robust relationships between retrieved ice concentrations and thin ice thickness estimates that differ between the two algorithms. These relationships define the approximate spatial coincidence of ice concentration and thickness isopleths. Using the 83% (ABA) and 91% (NT2) isopleths as polynya boundaries, we show that the computed coverage compares well with that using the estimated 10-cm thickness contour. The thin ice response characterized here suggests that in regions with polynyas, the retrieval results could be used to provide useful geophysical information, namely thickness and coverage.

Study on characteristics of a double-conductible channel organic thin-film transistor with an ultra-thin hole-blocking layer

International Nuclear Information System (INIS)

Guang-Cai, Yuan; Zheng, Xu; Su-Ling, Zhao; Fu-Jun, Zhang; Xue-Yan, Tian; Xu-Rong, Xu; Na, Xu

2009-01-01

The properties of top-contact organic thin-film transistors (TC-OTFTs) using ultra-thin 2, 9-dimethyl-4, 7-diphenyl-1, 10-phenanthroline (BCP) as a hole-blocking interlayer have been improved significantly and a BCP interlayer was inserted into the middle of the pentacene active layer. This paper obtains a fire-new transport mode of an OTFT device with double-conductible channels. The accumulation and transfer of the hole carriers are limited by the BCP interlayer in the vertical region of the channel. A huge amount of carriers is located not only at the interface between pentacene and the gate insulator, but also at the two interfaces of pentacene/BCP interlayer and pentacene/gate insulator, respectively. The results suggest that the BCP interlayer may be useful to adjust the hole accumulation and transfer, and can increase the hole mobility and output current of OTFTs. The TC-OTFTs with a BCP interlayer at V DS = −20 V showed excellent hole mobility μFE and threshold voltage V TH of 0.58 cm 2 /(V·s) and −4.6 V, respectively

Oxygen isotope systematics of chondrules in the Murchison CM2 chondrite and implications for the CO-CM relationship

Science.gov (United States)

Chaumard, Noël; Defouilloy, Céline; Kita, Noriko T.

2018-05-01

High-precision oxygen three-isotope measurements of olivine and pyroxene were performed on 29 chondrules in the Murchison CM2 chondrite by secondary ion mass spectrometry (SIMS). The oxygen isotope ratios of analyzed chondrules all plot very close to the primitive chondrule minerals (PCM) line. In each of 24 chondrules, the olivine and/or pyroxene grains analyzed show indistinguishable oxygen isotope ratios. Exceptions are minor occurrences of isotopically distinguished relict olivine grains, which were found in nine chondrules. The isotope homogeneity of these phenocrysts is consistent with a co-magmatic crystallization of olivine and pyroxene from the final chondrule melts and a significant oxygen isotope exchange between the ambient gas and the melts. Homogeneous type I chondrules with Mg#'s of 98.9-99.5 have host chondrule Δ17O values ranging from -6.0‰ to -4.1‰, with one exception (Δ17O: -1.2‰; Mg#: 99.6). Homogeneous chondrules with Mg#'s poor H2O ice (∼0.3-0.4× the CI dust; Δ17O > 0‰) and at dust enrichments of ∼300-2000×. Regarding the Mg# and oxygen isotope ratios, the chondrule populations sampled by CM and CO chondrites are similar and indistinguishable. The similarity of these 16O-rich components in CO and CM chondrites is also supported by the common Fe/Mn ratio of olivine in type II chondrules. Although they accreted similar high-temperature silicates, CO chondrites are anhydrous compared to CM chondrites, suggesting they derived from different parent bodies formed inside and outside the snow line, respectively. If chondrules in CO and CM chondrites formed at the same disk locations but the CM parent body accreted later than the CO parent body, the snow line might have crossed the common chondrule-forming region towards the Sun between the time of the CO and CM parent bodies accretion.

No rotating U.S. Testing of thin walled tubes

International Nuclear Information System (INIS)

Furlan, J.; Boulanger, G.; Mogavero, R.

1981-07-01

Thin walled tube ultrasonic testing is performed, with Lamb waves, using annular transducers and conical or helicoidal mirrors. The main advantage of this already known system is dispensing with rotation of tube and/or transducer. High speed control (30 cm/s and more) is then allowed. The present paper describes the parameters influencing the sensitivity has been improved by searching, theoretically and practically, the best suited Lamb wave modes, and by using transducers which are well characterized. Practical example of cladding tube U.S. testing is described

Designing High-Efficiency Thin Silicon Solar Cells Using Parabolic-Pore Photonic Crystals

Science.gov (United States)

Bhattacharya, Sayak; John, Sajeev

2018-04-01

We demonstrate the efficacy of wave-interference-based light trapping and carrier transport in parabolic-pore photonic-crystal, thin-crystalline silicon (c -Si) solar cells to achieve above 29% power conversion efficiencies. Using a rigorous solution of Maxwell's equations through a standard finite-difference time domain scheme, we optimize the design of the vertical-parabolic-pore photonic crystal (PhC) on a 10 -μ m -thick c -Si solar cell to obtain a maximum achievable photocurrent density (MAPD) of 40.6 mA /cm2 beyond the ray-optical, Lambertian light-trapping limit. For a slanted-parabolic-pore PhC that breaks x -y symmetry, improved light trapping occurs due to better coupling into parallel-to-interface refraction modes. We achieve the optimum MAPD of 41.6 mA /cm2 for a tilt angle of 10° with respect to the vertical axis of the pores. This MAPD is further improved to 41.72 mA /cm2 by introducing a 75-nm SiO2 antireflective coating on top of the solar cell. We use this MAPD and the associated charge-carrier generation profile as input for a numerical solution of Poisson's equation coupled with semiconductor drift-diffusion equations using a Shockley-Read-Hall and Auger recombination model. Using experimentally achieved surface recombination velocities of 10 cm /s , we identify semiconductor doping profiles that yield power conversion efficiencies over 29%. Practical considerations of additional upper-contact losses suggest efficiencies close to 28%. This improvement beyond the current world record is largely due to an open-circuit voltage approaching 0.8 V enabled by reduced bulk recombination in our thin silicon architecture while maintaining a high short-circuit current through wave-interference-based light trapping.

Surface morphology of thin lysozyme films produced by matrix-assisted pulsed laser evaporation (MAPLE)

DEFF Research Database (Denmark)

Purice, Andreea; Schou, Jørgen; Pryds, Nini

2007-01-01

Thin films of the protein, lysozyme, have been deposited by the matrix-assisted pulsed laser evaporation (MAPLE) technique. Frozen targets of 0.3-1.0 wt.% lysozyme dissolved in ultrapure water were irradiated by laser light at 355 mn with a fluence of 2 J/cm(2). The surface quality of the thin....... The concentration of lysozyme in the ice matrix apparently does not play any significant role for the morphology of the film. The morphology obtained with MAPLE has been compared with results for direct laser irradiation of a pressed lysozyme sample (i.e. pulsed laser deposition (PLD)). (C) 2007 Elsevier B.V. All...

Investigation of AgInS2 thin films grown by coevaporation

Science.gov (United States)

Arredondo, C. A.; Clavijo, J.; Gordillo, G.

2009-05-01

AgInS2 thin films were grown on soda-lime glass substrates by co-evaporation of the precursors in a two-step process. X-ray diffraction (XRD) measurements indicated that these compounds grow in different phases and with different crystalline structure depending upon the deposition conditions. However, through a parameter study, conditions were found to grow thin films containing only the AgInS2 phase with chalcopyrite type structure. In samples containing a mixture of several phases, the contribution in percentage terms of each phase to the whole compound was estimated with the help of the PowderCell simulation package. It was also found that the AgInS2 films present p-type conductivity, a high absorption coefficient (greater than 104 cm-1) and an energy band gap Eg of about 1.95 eV, indicating that this compound has good properties to perform as absorbent layer in thin film tandem solar cells. The effect of the deposition conditions on the optical and morphological properties was also investigated through spectral transmitance and atomic force microscopy (AFM) measurements.

Determination of the differential cross-section in hadronic e+e--annihilation events with hard, isolated, neutral particles

International Nuclear Information System (INIS)

Makowsky, M.

1982-10-01

Hadronic e + e - -annihilation events have been measured, by the CELLO-detector at PETRA at the center of mass energy Esub(cm) = 34 GeV and Esub(cm) = 22 GeV. Those events with hard, isolated, neutral particles are selected and explored. At Esub(cm) = 34 GeV the predominant source of these isolated photons is found to be initial state bremsstrahlung of the e + e - -annihilation. The measured photon distributions as function of its energy and the total cross section are investigated. The agreement with QED-predictions is good. (orig.) [de

Methodical Specifics of Thermal Experiments with Thin Carbon Reinforced Plates

Directory of Open Access Journals (Sweden)

O. V. Denisov

2015-01-01

Full Text Available Polymer composite materials (CM are widely used in creation of large space constructions, especially reflectors of space antennas. Composite materials should provide high level of specific stiffness and strength for space structures. Thermal conductivity in reinforcement plane is a significant factor in case of irregular heating space antennas. Nowadays, data on CM reinforcement plane thermal conductivity are limited and existing methods of its defining are imperfect. Basically, traditional methods allow us to define thermal conductivity in perpendicular direction towards the reinforcement plane on the samples of round or rectangular plate. In addition, the thickness of standard samples is larger than space antenna thickness. Consequently, new methods are required. Method of contact heating, which was developed by BMSTU specialists with long hollow carbon beam, could be a perspective way. This article is devoted to the experimental method of contact heating on the thin carbon plates.Thermal tests were supposed to provide a non-stationary temperature field with a gradient being co-directional with the plane reinforcement in the material sample. Experiments were conducted in vacuum chamber to prevent unstructured convection. Experimental thermo-grams processing were calculated by 1-d thermal model for a thin plate. Influence of uncertainty of experimental parameters, such as (radiation emission coefficients of sample surface, glue, temperature sensors and uncertainty of sensors placement on the result of defined thermal conductivity has been estimated. New data on the thermal conductivity in reinforcement plane were obtained within 295 - 375 K temperature range, which can be used to design and develop reflectors of precision space antennas. In the future it is expedient to conduct tests of thin-wall plates from carbon fiber-reinforced plastic in wide temperature range, especially in the low-range temperatures.

Particle energy loss spectroscopy and SEM studies of topography development in thin aluminium films implanted with high doses of helium

International Nuclear Information System (INIS)

Barfoot, K.M.; Webb, R.P.; Donnelly, S.E.

1984-01-01

Development of topography in thin (55.5 μg cm -2 ) self-supporting aluminium films, caused by high fluence (approx. 10 17 ions cm -2 ) irradiation with 5 keV helium ions, has been observed. This has been achieved by measuring the topography-enhanced energy straggling of 0.40 MeV 4 He + ions transmitted through the foils and detected with an electrostatic analyser of resolution 0.2 keV. Features, about 0.7 μm in width, are observed with scanning electron microscopy. TRIM Monte Carlo calculations of the implantation processes are performed in order to follow the helium implantation and damage depth distributions. It is deduced that a form of thin film micro-wrinkling has occurred which is caused by the relief of stress brought about by the implantation of helium. (author)

Raman scattering study of phonons in Bi-based superconductor thin films

International Nuclear Information System (INIS)

Mejia-Garcia, C.; Diaz-Valdes, E.; Contreras-Puente, G.; Lopez-Lopez, J.L.; Jergel, M.; Morales, A.

2004-01-01

Raman spectra were obtained from samples of Bi-Pb-Sr-Ca-Cu-O (BPSCCO) thin films after varying several growth parameters, such as covering material, annealing time (t R ), annealing temperature (T R ), and nominal lead content (x). Thin films with the nominal composition Bi 1.4 Pb x Sr 2 Ca 2 Cu 3 O δ were grown on MgO substrates by a spray pyrolysis technique, followed by a solid state reaction. The results of Raman scattering measurements at room temperature show a series of vibrational optical modes within the range 300-900 cm -1 . The assignment of these modes was made by involving mainly the 2212 and 2223 phases and was confirmed by both X-ray diffraction and resistance in dependence of the temperature (R-T) measurements as well

Ionic conductivities of lithium phosphorus oxynitride glasses, polycrystals, and thin films

International Nuclear Information System (INIS)

Wang, B.; Bates, J.B.; Chakoumakos, B.C.; Sales, B.C.; Kwak, B.S.; Zuhr, R.A.; Robertson, J.D.

1994-11-01

Various lithium phosphorus oxynitrides have been prepared in the form of glasses, polycrystals, and thin films. The structures of these compounds were investigated by X-ray and neutron diffraction, X-ray photoelectron spectroscopy (XPS), and high-performance liquid chromatography (HPLC). The ac impedance measurements indicate a significant improvement of ionic conductivity as the result of incorporation of nitrogen into the structure. In the case of polycrystalline Li 2.88 PO 3.73 N 0.14 with the γ-Li 3 PO 4 structure, the conductivity increased by several orders of magnitude on small addition of nitrogen. The highest conductivities in the bulk glasses and thin films were found to be 3.0 x 10 -7 and 8.9 x 10 -7 S·cm -1 at 25 degrees C, respectively

Amorphous silicon thin-film solar cells on glass fiber textiles

Energy Technology Data Exchange (ETDEWEB)

Plentz, Jonathan, E-mail: jonathan.plentz@leibniz-ipht.de; Andrä, Gudrun; Pliewischkies, Torsten; Brückner, Uwe; Eisenhawer, Björn; Falk, Fritz

2016-02-15

Graphical abstract: - Highlights: • Amorphous silicon solar cells on textile glass fiber fabrics are demonstrated. • Open circuit voltages of 883 mV show shunt-free contacting on non-planar fabrics. • Short-circuit current densities of 3.7 mA/cm{sup 2} are limited by transmission losses. • Fill factors of 43.1% and pseudo fill factors of 70.2% show high series resistance. • Efficiencies of 1.4% and pseudo efficiencies of 2.1% realized on textile fabrics. - Abstract: In this contribution, amorphous silicon thin-film solar cells on textile glass fiber fabrics for smart textiles are prepared and the photovoltaic performance is characterized. These solar cells on fabrics delivered open circuit voltages up to 883 mV. This shows that shunt-free contacting of the solar cells was successful, even in case of non-planar fabrics. The short-circuit current densities up to 3.7 mA/cm{sup 2} are limited by transmission losses in a 10 nm thin titanium layer, which was used as a semi-transparent contact. The low conductivity of this layer limits the fill factor to 43.1%. Pseudo fill factors, neglecting the series resistance, up to 70.2% were measured. Efficiencies up to 1.4% and pseudo efficiencies up to 2.1% were realized on textile fabrics. A transparent conductive oxide could further improve the efficiency to above 5%.

Enhanced electrical and optical properties of CdS:Na thin films by photochemical deposition

Science.gov (United States)

Kumar, V. Nirmal; Suriakarthick, R.; Gopalakrishnan, R.; Hayakawa, Y.

2017-06-01

CdS:Na thin film was deposited on a glass substrate by photochemical deposition from aqueous solution contained CdSO4.5H2O and Na2S2O3 as cation and anion sources, respectively. The anion source Na2S2O3 served as Na dopant source. The deposited film exhibited cubic phase of CdS and incorporation of Na was revealed from X-ray diffraction study. The incorporation of Na in CdS changed the surface morphology from spherical to nano rods. CdS:Na thin film showed blue shift in its absorption spectrum which was more desirable for transmitting higher energy photons (visible region) in thin film solar cells. The Raman analysis confirmed 1 LO and 2 LO process at 297 and 593 cm-1, respectively. The carrier concentration of CdS increased with the inclusion of Na and its resistivity value decreased. Both the electrical and optical properties of CdS were enhanced in CdS:Na thin films which was desirable as a window layer material for photovoltaic application.

Facile green synthesis of silver nanodendrite/cellulose acetate thin film electrodes for flexible supercapacitors.

Science.gov (United States)

Devarayan, Kesavan; Park, Jiyoung; Kim, Hak-Yong; Kim, Byoung-Suhk

2017-05-01

In this study, we present a highly efficient and economical solution called as 'in situ hydrogenation' for preparation of highly conductive thin film electrode based on silver nanodendrites. The silver nanodendrite (AgND)/cellulose acetate (CA) thin film electrodes exhibited sheet resistance ranging from 0.32ohm/sq to 122.1ohm/sq which could be controlled by changing the concentration of both silver and polymer. In addition, these electrodes exhibited outstanding toughness during the bending test. Further, these thin film electrodes have great potential for scale-up with an average weight of 3mg/cm 2 and can be also combined with active nanomaterials such as multiwalled carbon nanotubes (MWCNTs) to fabricate AgND/CA/MWCNTs thin film for high-performance flexible supercapacitor electrode. The AgND/CA/MWCNTs electrodes exhibited a maximum specific capacitance of 237F/g at a current density of 0.3A/g. After 1000 cycles, the AgND/MWCNT/CA exhibited a decrease of 16.0% of specific capacitance. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characterization of Thin Pixel Sensor Modules Interconnected with SLID Technology Irradiated to a Fluence of 2$\\cdot 10^{15}$\\,n$_{\\mathrm{eq}}$/cm$^2$

CERN Document Server

INSPIRE-00237859; Beimforde, M.; Macchiolo, A.; Moser, H.G.; Nisius, R.; Richter, R.H.

2011-01-01

A new module concept for future ATLAS pixel detector upgrades is presented, where thin n-in-p silicon sensors are connected to the front-end chip exploiting the novel Solid Liquid Interdiffusion technique (SLID) and the signals are read out via Inter Chip Vias (ICV) etched through the front-end. This should serve as a proof of principle for future four-side buttable pixel assemblies for the ATLAS upgrades, without the cantilever presently needed in the chip for the wire bonding. The SLID interconnection, developed by the Fraunhofer EMFT, is a possible alternative to the standard bump-bonding. It is characterized by a very thin eutectic Cu-Sn alloy and allows for stacking of different layers of chips on top of the first one, without destroying the pre-existing bonds. This paves the way for vertical integration technologies. Results of the characterization of the first pixel modules interconnected through SLID as well as of one sample irradiated to $2\\cdot10^{15}$\\,\

Peripartum Morbidity after Cesarean Delivery for Arrest of Dilation at 4 to 5 cm Compared with 6 to 10 cm.

Science.gov (United States)

Dahlke, Joshua D; Sperling, Jeffrey D; Has, Phinnara; Lovgren, Todd R; Connealy, Brendan D; Rouse, Dwight J

2018-04-24

 Given that recent consensus guidelines established to decrease cesarean delivery (CD) rates use 6 cm to define the onset of the active phase of labor, our objective was to evaluate maternal and neonatal outcomes after CD for the indication of arrest of dilation at 4 to 5 cm compared with ≥ 6 cm.  We performed a secondary analysis using data from the Maternal Fetal-Medicine Units Network Cesarean Registry. We included nulliparous women with term, singleton, vertex gestations who underwent primary CD for arrest of dilation. We compared those who reached a maximum cervical dilation of 4 to 5 cm with those of ≥6 cm. Our primary outcome was composite maternal morbidity that included chorioamnionitis, endometritis, transfusion, wound complication, operative injury, intensive care unit admission, or death.  Of the 73,257 women in the dataset, 5,681 met the inclusion criteria. After adjusting for confounders, there was no difference in composite maternal (adjusted odds ratio [aOR]: 1.19; 95% confidence interval [CI]: 0.94-1.52) or neonatal morbidity (aOR: 0.94; 95% CI: 0.79-1.10) between the groups.  In this historical cohort, maternal and neonatal outcomes after CD for arrest of dilation ≥ 6 cm were comparable to those performed at 4 to 5 cm and support recent labor management guidelines. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Metallic transport and large anomalous Hall effect at room temperature in ferrimagnetic Mn4N epitaxial thin film

International Nuclear Information System (INIS)

Shen, Xi; Shigematsu, Kei; Chikamatsu, Akira; Fukumura, Tomoteru; Hirose, Yasushi; Hasegawa, Tetsuya

2014-01-01

We report the electrical transport properties of ferrimagnetic Mn 4 N (001) epitaxial thin films grown by pulsed laser deposition on MgO (001) substrates. The Mn 4 N thin films were tetragonally distorted with a ratio of out-of-plane to in-plane lattice constants of 0.987 and showed perpendicular magnetic anisotropy with an effective magnetic anisotropy constant of 0.16 MJ/m 3 , which is comparable with that of a recently reported molecular-beam-epitaxy-grown film. The thin films exhibited metallic transport with a room temperature resistivity of 125 μΩ cm in addition to a large anomalous Hall effect with a Hall angle tangent of 0.023.

130 MeV Au ion irradiation induced dewetting on In2Te3 thin film

International Nuclear Information System (INIS)

Matheswaran, P.; Abhirami, K.M.; Gokul, B.; Sathyamoorthy, R.; Prakash, Jai; Asokan, K.; Kanjilal, D.

2012-01-01

Highlights: ► In 2 Te 3 phase formed from In/Te bilayer by 130 MeV Au ion irradiation. ► Lower fluence results mixed phases with initial state of dewetting. ► At higher fluence, In 2 Te 3 phase with complete dewetting pattern is formed. ► Thermal spike model is used to explain the inter face mixing phenomena. ► SHI irradiation may be used to functionalize the structural and surface properties of thin films. - Abstract: In/Te bilayer thin films were prepared by sequential thermal evaporation and subsequently irradiated by 130 MeV Au ions. The pristine and irradiated samples were characterized by X-ray diffraction (XRD), Rutherford backscattering spectrometry (RBS), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) techniques. RBS spectra reveal the sputtering of Te film and interface mixing, with increasing fluence. The surface morphology showed the beginning of dewetting of Te thin film and formation of the partially connected with the mixed zones at the fluence of 1 × 10 13 ions/cm 2 . At the higher fluence of 3 × 10 13 ions/cm 2 , dewetted structures were isolated at the surface. Above results are explained based on the formation of craters, sputtering and dewetting followed by inter-diffusion at the interface of molten zones due to thermal spike induced by Au ions.

Study on structural integrity of thinned wall piping against seismic loading-overview and future program

International Nuclear Information System (INIS)

Nakamura, Izumi; Otani, Akihito; Shiratori, Masaki

2005-01-01

In order to clarify the behavior of thinned wall pipes under seismic events, cyclic in-plane and/or out-of-plane bending tests on thinned straight pipe and elbow and also shaking table tests using degraded piping system models were conducted. Relation between the failure mode and thinned condition and the influence of the final failure mode of degraded piping systems were investigated. In addition to these experiments, elastic-plastic FEM analysis using ABAQUS were conducted on thinned piping elements. It has been found that the strain concentrated point could be predicted and the cause of its generation could be explained by the simulated deformation behavior of the pipe. In order to predict the piping system's maximum response under elastic-plastic response, a simple response prediction method was proposed. Further tests and safety margin analyses of thinned pipes against seismic loading will be performed. (T. Tanaka)

Mechanical characterization of YBCO thin films using nanoindentation and finite element method

Energy Technology Data Exchange (ETDEWEB)

Zhang, Weixing [The Ministry of Education of China (China). Key Lab. of Mechanics on Environment and Disaster in Western China; Lanzhou Univ. (China). College of Civil Engineering and Mechanics

2017-09-15

The mechanical properties of YBCO thin film deposited on SrTiO{sub 3} (100) substrates by magnetron sputtering were determined using Berkovich nanoindentation and scanning electron microscopy. Hardness and elastic modulus were determined via the Oliver-Pharr method from indentation load-depth curves. The hardness values of the YBCO thin film show depth dependence, i. e., indentation size effect, which arose from the surface roughness as detected by scanning electron microscopy. Multiple pop-in events were observed on the loading curves, however, no obvious pop-out takes place during the elastic recovery. In addition, an effective analytical method accommodating the indenter imperfection was proposed and validated against experimental data in terms of elastic modulus, yield stress and friction angle using the Drucker-Prager yield criterion for the YBCO thin film.

The BRIDGE HadCM3 family of climate models: HadCM3@Bristol v1.0

Science.gov (United States)

Valdes, Paul J.; Armstrong, Edward; Badger, Marcus P. S.; Bradshaw, Catherine D.; Bragg, Fran; Crucifix, Michel; Davies-Barnard, Taraka; Day, Jonathan J.; Farnsworth, Alex; Gordon, Chris; Hopcroft, Peter O.; Kennedy, Alan T.; Lord, Natalie S.; Lunt, Dan J.; Marzocchi, Alice; Parry, Louise M.; Pope, Vicky; Roberts, William H. G.; Stone, Emma J.; Tourte, Gregory J. L.; Williams, Jonny H. T.

2017-10-01

Understanding natural and anthropogenic climate change processes involves using computational models that represent the main components of the Earth system: the atmosphere, ocean, sea ice, and land surface. These models have become increasingly computationally expensive as resolution is increased and more complex process representations are included. However, to gain robust insight into how climate may respond to a given forcing, and to meaningfully quantify the associated uncertainty, it is often required to use either or both ensemble approaches and very long integrations. For this reason, more computationally efficient models can be very valuable tools. Here we provide a comprehensive overview of the suite of climate models based around the HadCM3 coupled general circulation model. This model was developed at the UK Met Office and has been heavily used during the last 15 years for a range of future (and past) climate change studies, but has now been largely superseded for many scientific studies by more recently developed models. However, it continues to be extensively used by various institutions, including the BRIDGE (Bristol Research Initiative for the Dynamic Global Environment) research group at the University of Bristol, who have made modest adaptations to the base HadCM3 model over time. These adaptations mean that the original documentation is not entirely representative, and several other relatively undocumented configurations are in use. We therefore describe the key features of a number of configurations of the HadCM3 climate model family, which together make up HadCM3@Bristol version 1.0. In order to differentiate variants that have undergone development at BRIDGE, we have introduced the letter B into the model nomenclature. We include descriptions of the atmosphere-only model (HadAM3B), the coupled model with a low-resolution ocean (HadCM3BL), the high-resolution atmosphere-only model (HadAM3BH), and the regional model (HadRM3B). These also include

77 FR 8877 - ICD-9-CM Coordination and Maintenance (C&M) Committee Meeting

Science.gov (United States)

2012-02-15

...), Classifications and Public Health Data Standards Staff, announces the following meeting. Name: ICD-9-CM... proposed modifications to the International Classification of Diseases, Ninth-Revision, Clinical... Infusion of Glucarpidase ICD-10 Updates: ICD-10 MS-DRG Update ICD-10 HAC Translation List Impact of ICD-10...

Nonepitaxial Thin-Film InP for Scalable and Efficient Photocathodes.

Science.gov (United States)

Hettick, Mark; Zheng, Maxwell; Lin, Yongjing; Sutter-Fella, Carolin M; Ager, Joel W; Javey, Ali

2015-06-18

To date, some of the highest performance photocathodes of a photoelectrochemical (PEC) cell have been shown with single-crystalline p-type InP wafers, exhibiting half-cell solar-to-hydrogen conversion efficiencies of over 14%. However, the high cost of single-crystalline InP wafers may present a challenge for future large-scale industrial deployment. Analogous to solar cells, a thin-film approach could address the cost challenges by utilizing the benefits of the InP material while decreasing the use of expensive materials and processes. Here, we demonstrate this approach, using the newly developed thin-film vapor-liquid-solid (TF-VLS) nonepitaxial growth method combined with an atomic-layer deposition protection process to create thin-film InP photocathodes with large grain size and high performance, in the first reported solar device configuration generated by materials grown with this technique. Current-voltage measurements show a photocurrent (29.4 mA/cm(2)) and onset potential (630 mV) approaching single-crystalline wafers and an overall power conversion efficiency of 11.6%, making TF-VLS InP a promising photocathode for scalable and efficient solar hydrogen generation.

Nanomagnetic behavior of fullerene thin films in Earth magnetic field in dark and under polarization light influences.

Science.gov (United States)

Koruga, Djuro; Nikolić, Aleksandra; Mihajlović, Spomenko; Matija, Lidija

2005-10-01

In this paper magnetic fields intensity of C60 thin films of 60 nm and 100 nm thickness under the influence of polarization lights are presented. Two proton magnetometers were used for measurements. Significant change of magnetic field intensity in range from 2.5 nT to 12.3 nT is identified as a difference of dark and polarization lights of 60 nm and 100 nm thin films thickness, respectively. Specific power density of polarization light was 40 mW/cm2. Based on 200 measurement data average value of difference between magnetic intensity of C60 thin films, with 60 nm and 100 nm thickness, after influence of polarization light, were 3.9 nT and 9.9 nT respectively.

Air stable n-doping of WSe2 by silicon nitride thin films with tunable fixed charge density

International Nuclear Information System (INIS)

Chen, Kevin; Kiriya, Daisuke; Hettick, Mark; Tosun, Mahmut; Ha, Tae-Jun; Madhvapathy, Surabhi Rao; Desai, Sujay; Sachid, Angada; Javey, Ali

2014-01-01

Stable n-doping of WSe 2 using thin films of SiN x deposited on the surface via plasma-enhanced chemical vapor deposition is presented. Positive fixed charge centers inside SiN x act to dope WSe 2 thin flakes n-type via field-induced effect. The electron concentration in WSe 2 can be well controlled up to the degenerate limit by simply adjusting the stoichiometry of the SiN x through deposition process parameters. For the high doping limit, the Schottky barrier width at the metal/WSe 2 junction is significantly thinned, allowing for efficient electron injection via tunneling. Using this doping scheme, we demonstrate air-stable WSe 2 n-MOSFETs with a mobility of ∼70 cm 2 /V s

Observations of hydrotectonic stress/strain events at a basement high at the Nicoya outer rise

Science.gov (United States)

Tryon, M. D.; Brown, K. M.

2005-12-01

There is substantial and growing evidence from heat flow and coring investigations that the oceanic plate off Costa Rica is highly hydrologically active and that this activity is responsible for one of the most anomalously cold thermal environments encountered in the oceanic environment. Recent work by Fisher, et al. has identified limited regions above certain topographic highs with extremely high heat flows. Pore water profiles from cores above these thinly sedimented basement highs suggest upward flow on the order of ~1 cm/yr. These highs may be the principal regions of out-flow from the basement in this region and, thus, can potentially be used to constrain the general level of hydrologic activity. The nine Chemical and Aqueous Transport (CAT) meters we deployed at one of the highest heatflow sites provide a temporal record of both in-flow and out-flow of aqueous fluids at rates as low as 0.1 mm/yr. Our objective was to provide a direct measurement of long term flow rates to address the following questions: (1) What are the characteristic fluid fluxes at basement highs of the low heat flow region of the northern Costa Rican incoming plate, and (2) is this flow temporally variable? The results of the instrument deployments agree quite closely in general with the coring results in that the background rates are on the order of 1 cm/yr or less. There is, however, considerable detail in the temporal records which suggest small scale tectonic stress transients causing temporary increases in flow rate. While this is certainly not an area of major tectonic activity, the site is located at the top of the outer rise where one would expect bending-related stress and fault reactivation to occur. The CAT meters are capable of detecting minute strain events in the underlying sediments and therefore may be detecting small localized strain events. Two periods of increased flow lasting a few weeks each occur during the 5 month deployment and are indicated on all of the

Roughness-based monitoring of transparency and conductivity in boron-doped ZnO thin films prepared by spray pyrolysis

International Nuclear Information System (INIS)

Gaikwad, Rajendra S.; Bhande, Sambhaji S.; Mane, Rajaram S.; Pawar, Bhagwat N.; Gaikwad, Sanjay L.; Han, Sung-Hwan; Joo, Oh-Shim

2012-01-01

Graphical abstract: Display Omitted Highlights: ► We report surface roughness dependent transparency and conductivity in ZnO films. ► The surface roughness with respected to boron doping concentrations is studied. ► Boron doped and pristine Zinc oxide thin films have showed ≥95% transmittance. ► Increased carrier concentration of 9.21 × 10 21 cm −3 revealed from Hall measurement. -- Abstract: Sprayed polycrystalline ZnO and boron-doped ZnO thin films composed of spherical grains of 25–32 nm in diameters are used in roughness measurement and further correlated with the transparency and the conductivity characteristics. The surface roughness is increased up to Zn 0.98 B 0.02 O and then declined at higher boron concentrations. The sprayed ZnO films revealed ≥95% transmittance in the visible wavelength range, 1.956 × 10 −4 Ω cm electrical resistivity, 46 cm 2 /V s Hall mobility and 9.21 × 10 21 cm −3 charge carrier concentration. The X-ray photoelectron spectroscopy study has confirmed 0.15 eV binding energy change for Zn 2p 3/2 when 2 at% boron content is mixed without altering electro-optical properties substantially. Finally, using soft modeling importance of these textured ZnO over non-textured films for enhancing the solar cells performance is explored.

Thin pixel development for the SuperB silicon vertex tracker

Energy Technology Data Exchange (ETDEWEB)

Rizzo, G., E-mail: giuliana.rizzo@pi.infn.it [INFN-Pisa and Universita di Pisa (Italy); Avanzini, C.; Batignani, G.; Bettarini, S.; Bosi, F.; Ceccanti, M.; Cenci, R.; Cervelli, A.; Crescioli, F.; Dell' Orso, M.; Forti, F.; Giannetti, P.; Giorgi, M.A. [INFN-Pisa and Universita di Pisa (Italy); Lusiani, A. [Scuola Normale Superiore and INFN-Pisa (Italy); Gregucci, S.; Mammini, P.; Marchiori, G.; Massa, M.; Morsani, F.; Neri, N. [INFN-Pisa and Universita di Pisa (Italy); and others

2011-09-11

The high luminosity SuperB asymmetric e{sup +}e{sup -} collider, to be built near the INFN National Frascati Laboratory in Italy, has been designed to deliver a luminosity greater than 10{sup 36} cm{sup -2} s{sup -1} with moderate beam currents and a reduced center of mass boost with respect to earlier B-Factories. An improved vertex resolution is required for precise time-dependent measurements and the SuperB Silicon Vertex Tracker will be equipped with an innermost layer of small radius (about 1.5 cm), resolution of 10-15{mu}m in both coordinates, low material budget (<1% X0), and able to withstand a background rate of several tens of MHz/cm{sup 2}. The ambitious goal of designing a thin pixel device with these stringent requirements is being pursued with specific R and D programs on different technologies: hybrid pixels, CMOS MAPS and pixel sensors developed with vertical integration technology. The latest results on the various pixel options for the SuperB SVT will be presented.

Operation of low-noise single-gap RPC modules exposed to ionisation rates up to 1 kHz/cm$^2$

CERN Document Server

Cwiok, M; Dominik, Wojciech; Górski, M; Królikowski, J; 10.1016/j.nima.2004.06.123

2004-01-01

Two single gap medium-size RPC modules, made of bakelite plates of very good mechanical quality of the surface and having initial volume resistivity of 1 multiplied by 10**1**0 omegacm, were tested in the Gamma Irradiation Facility at CERN at ionisation rates up to 1 kHz/cm **3. The internal surfaces facing the gas volume of one RPC module were cladded with a thin layer of linseed oil varnish for comparison of oiled and non-oiled RPC operation. The results refer to the gas mixture of C//2H//2F //4/isobutane (97:3) with SF//6 addition below 1%. The single gap modules exhibited full detection efficiency plateau for the high voltage range of about 1 kV at full intensity of gamma rays. Good timing characteristics allowed to reach 95% efficiency at fully opened irradiation source with time window of 20 ns. The intrinsic noise rate for a non-oiled and an oiled RPC gap was, respectively, below 5 and 1 Hz/cm**2 at full efficiency over 1 k V voltage range.

Organic photovoltaics using thin gold film as an alternative anode to indium tin oxide

International Nuclear Information System (INIS)

Haldar, Amrita; Yambem, Soniya D.; Liao, Kang-Shyang; Alley, Nigel J.; Dillon, Eoghan P.; Barron, Andrew R.; Curran, Seamus A.

2011-01-01

Indium Tin Oxide (ITO) is the most commonly used anode as a transparent electrode and more recently as an anode for organic photovoltaics (OPVs). However, there are significant drawbacks in using ITO which include high material costs, mechanical instability including brittleness and poor electrical properties which limit its use in low-cost flexible devices. We present initial results of poly(3-hexylthiophene): phenyl-C 61 -butyric acid methyl ester OPVs showing that an efficiency of 1.9% (short-circuit current 7.01 mA/cm 2 , open-circuit voltage 0.55 V, fill factor 0.49) can be attained using an ultra thin film of gold coated glass as the device anode. The initial I-V characteristics demonstrate that using high work function metals when the thin film is kept ultra thin can be used as a replacement to ITO due to their greater stability and better morphological control.