WorldWideScience

Sample records for antireflection coatings

  1. Loss/gain-induced ultrathin antireflection coatings

    OpenAIRE

    Jie Luo; Sucheng Li; Bo Hou; Yun Lai

    2016-01-01

    Tradional antireflection coatings composed of dielectric layers usually require the thickness to be larger than quarter wavelength. Here, we demonstrate that materials with permittivity or permeability dominated by imaginary parts, i.e. lossy or gain media, can realize non-resonant antireflection coatings in deep sub-wavelength scale. Interestingly, while the reflected waves are eliminated as in traditional dielectric antireflection coatings, the transmitted waves can be enhanced or reduced, ...

  2. Loss/gain-induced ultrathin antireflection coatings.

    Science.gov (United States)

    Luo, Jie; Li, Sucheng; Hou, Bo; Lai, Yun

    2016-06-28

    Tradional antireflection coatings composed of dielectric layers usually require the thickness to be larger than quarter wavelength. Here, we demonstrate that materials with permittivity or permeability dominated by imaginary parts, i.e. lossy or gain media, can realize non-resonant antireflection coatings in deep sub-wavelength scale. Interestingly, while the reflected waves are eliminated as in traditional dielectric antireflection coatings, the transmitted waves can be enhanced or reduced, depending on whether gain or lossy media are applied, respectively. We provide a unified theory for the design of such ultrathin antireflection coatings, showing that under different polarizations and incident angles, different types of ultrathin coatings should be applied. Especially, under transverse magnetic polarization, the requirement shows a switch between gain and lossy media at Brewster angle. As a proof of principle, by using conductive films as a special type of lossy antireflection coatings, we experimentally demonstrate the suppression of Fabry-Pérot resonances in a broad frequency range for microwaves. This valuable functionality can be applied to remove undesired resonant effects, such as the frequency-dependent side lobes induced by resonances in dielectric coverings of antennas. Our work provides a guide for the design of ultrathin antireflection coatings as well as their applications in broadband reflectionless devices.

  3. Sol-gel antireflective coating on plastics

    Science.gov (United States)

    Ashley, Carol S.; Reed, Scott T.

    1990-01-01

    An antireflection film made from a reliquified sol-gel hydrolyzation, condensation polymeric reaction product of a silicon, alkoxides and/or metal alkoxides, or mixtures thereof. The film is particularly useful for coating plastics.

  4. Antireflective Coatings for Glass and Transparent Polymers

    NARCIS (Netherlands)

    Buskens, P.; Burghoorn, M.; Danho Mourad, M.C.; Vroon, Z.

    2016-01-01

    Antireflective coatings (ARCs) are applied to reduce surface reflections. We review coatings that reduce the reflection of the surface of the transparent substrates float glass, polyethylene terephthalate, poly(methyl methacrylate), and polycarbonate. Three main coating concepts exist to lower the r

  5. Plasmonic and silicon spherical nanoparticle antireflective coatings

    OpenAIRE

    K. V. Baryshnikova; M. I. Petrov; Babicheva, V. E.; Belov, P. A.

    2016-01-01

    Over the last decade, plasmonic antireflecting nanostructures have been extensively studied to be utilized in various optical and optoelectronic systems such as lenses, solar cells, photodetectors, and others. The growing interest to all-dielectric photonics as an alternative optical technology along with plasmonics motivates us to compare antireflective properties of plasmonic and all-dielectric nanoparticle coatings based on silver and crystalline silicon respectively. Our simulation result...

  6. ANTIREFLECTION MULTILAYER COATINGS WITH THIN METAL LAYERS

    Directory of Open Access Journals (Sweden)

    L. A. Gubanova

    2016-03-01

    Full Text Available The design of anti-reflective coatings for metal surfaces of Al, Ti, N,i Cr is proposed. The coatings have the form of alternating layers of dielectric/metal/dielectric with the number of cells up to15. The method of calculation of such coatings is proposed. We have calculated the coatings of the type [HfO2/Cr/HfO2]15, [ZrO2/Ti/Al2O3]15, [ZrO2/Cr/ZrO2]15. It is shown that the proposed interference coatings provide reduction of the residual reflectance of the metal several times (from 3.5 to 6.0 in a wide spectral range (300-1000 nm. The proposed coatings can be recommended as anti-reflective coatings for energy saving solar systems and batteries, and photovoltaic cells.

  7. Inexpensive Antireflection Coating for Solar Cells

    Science.gov (United States)

    Tracy, C. E.; Kern, W.; Vibronek, R. D.

    1982-01-01

    Continuous method for applying antireflection coating to solar cells increases efficiency of devices by preventing energy from being reflected away, but adds little to manufacturing cost. Method consists of spraying solution on cells or glass collector plates, drying sprayed layer, and curing it. Solution is formulated to spread evenly over surfaces.

  8. Plasmonic and silicon spherical nanoparticle antireflective coatings

    Science.gov (United States)

    Baryshnikova, K. V.; Petrov, M. I.; Babicheva, V. E.; Belov, P. A.

    2016-03-01

    Over the last decade, plasmonic antireflecting nanostructures have been extensively studied to be utilized in various optical and optoelectronic systems such as lenses, solar cells, photodetectors, and others. The growing interest to all-dielectric photonics as an alternative optical technology along with plasmonics motivates us to compare antireflective properties of plasmonic and all-dielectric nanoparticle coatings based on silver and crystalline silicon respectively. Our simulation results for spherical nanoparticles array on top of amorphous silicon show that both silicon and silver coatings demonstrate strong antireflective properties in the visible spectral range. For the first time, we show that zero reflectance from the structure with silicon coatings originates from the destructive interference of electric- and magnetic-dipole responses of nanoparticle array with the wave reflected from the substrate, and we refer to this reflection suppression as substrate-mediated Kerker effect. We theoretically compare the silicon and silver coating effectiveness for the thin-film photovoltaic applications. Silver nanoparticles can be more efficient, enabling up to 30% increase of the overall absorbance in semiconductor layer. Nevertheless, silicon coatings allow up to 64% absorbance increase in the narrow band spectral range because of the substrate-mediated Kerker effect, and band position can be effectively tuned by varying the nanoparticles sizes.

  9. Optical enhancing durable anti-reflective coating

    Energy Technology Data Exchange (ETDEWEB)

    Maghsoodi, Sina; Varadarajan, Aravamuthan; Movassat, Meisam

    2016-07-05

    Disclosed herein are polysilsesquioxane based anti-reflective coating (ARC) compositions, methods of preparation, and methods of deposition on a substrate. In embodiments, the polysilsesquioxane of this disclosure is prepared in a two-step process of acid catalyzed hydrolysis of organoalkoxysilane followed by addition of tetralkoxysilane that generates silicone polymers with >40 mol % silanol based on Si-NMR. These high silanol siloxane polymers are stable and have a long shelf-life in the polar organic solvents at room temperature. Also disclosed are low refractive index ARC made from these compositions with and without additives such as porogens, templates, Si--OH condensation catalyst and/or nanofillers. Also disclosed are methods and apparatus for applying coatings to flat substrates including substrate pre-treatment processes, coating processes including flow coating and roll coating, and coating curing processes including skin-curing using hot-air knives. Also disclosed are coating compositions and formulations for highly tunable, durable, highly abrasion-resistant functionalized anti-reflective coatings.

  10. High gain durable anti-reflective coating

    Energy Technology Data Exchange (ETDEWEB)

    Maghsoodi, Sina; Brophy, Brenor L.; Colson, Thomas E.; Gonsalves, Peter R.; Abrams, Ze' ev R.

    2016-07-26

    Disclosed herein are polysilsesquioxane-based anti-reflective coating (ARC) compositions, methods of preparation, and methods of deposition on a substrate. In one embodiment, the polysilsesquioxane of this disclosure is prepared in a two-step process of acid catalyzed hydrolysis of organoalkoxysilane followed by addition of tetralkoxysilane that generates silicone polymers with >40 mol % silanol based on Si-NMR. These high silanol siloxane polymers are stable and have a long shelf-life in polar organic solvents at room temperature. Also disclosed are low refractive index ARC made from these compositions with and without additives such as porogens, templates, thermal radical initiator, photo radical initiators, crosslinkers, Si--OH condensation catalyst and nano-fillers. Also disclosed are methods and apparatus for applying coatings to flat substrates including substrate pre-treatment processes, coating processes and coating curing processes including skin-curing using hot-air knives. Also disclosed are coating compositions and formulations for highly tunable, durable, highly abrasion-resistant functionalized anti-reflective coatings.

  11. ANTIREFLECTION MULTILAYER COATINGS WITH THIN METAL LAYERS

    OpenAIRE

    L. A. Gubanova

    2016-01-01

    The design of anti-reflective coatings for metal surfaces of Al, Ti, N,i Cr is proposed. The coatings have the form of alternating layers of dielectric/metal/dielectric with the number of cells up to15. The method of calculation of such coatings is proposed. We have calculated the coatings of the type [HfO2/Cr/HfO2]15, [ZrO2/Ti/Al2O3]15, [ZrO2/Cr/ZrO2]15. It is shown that the proposed interference coatings provide reduction of the residual reflectance of the metal several times (from 3.5 to 6...

  12. Buried nanoantenna arrays: versatile antireflection coating.

    Science.gov (United States)

    Kabiri, Ali; Girgis, Emad; Capasso, Federico

    2013-01-01

    Reflection is usually a detrimental phenomenon in many applications such as flat-panel-displays, solar cells, photodetectors, infrared sensors, and lenses. Thus far, to control and suppress the reflection from a substrate, numerous techniques including dielectric interference coatings, surface texturing, adiabatic index matching, and scattering from plasmonic nanoparticles have been investigated. A new technique is demonstrated to manage and suppress reflection from lossless and lossy substrates. It provides a wider flexibility in design versus previous methods. Reflection from a surface can be suppressed over a narrowband, wideband, or multiband frequency range. The antireflection can be dependent or independent of the incident wave polarization. Moreover, antireflection at a very wide incidence angle can be attained. The reflection from a substrate is controlled by a buried nanoantenna array, a structure composed of (1) a subwavelength metallic array and (2) a dielectric cover layer referred to as a superstrate. The material properties and thickness of the superstrate and nanoantennas' geometry and periodicity control the phase and intensity of the wave circulating inside the superstrate cavity. A minimum reflectance of 0.02% is achieved in various experiments in the mid-infrared from a silicon substrate. The design can be integrated in straightforward way in optical devices. The proposed structure is a versatile AR coating to optically impedance matches any substrate to free space in selected any narrow and broadband spectral response across the entire visible and infrared spectrum.

  13. Self-Cleaning Antireflective Optical Coatings

    KAUST Repository

    Guldin, Stefan

    2013-11-13

    Low-cost antireflection coatings (ARCs) on large optical surfaces are an ingredient-technology for high-performance solar cells. While nanoporous thin films that meet the zero-reflectance conditions on transparent substrates can be cheaply manufactured, their suitability for outdoor applications is limited by the lack of robustness and cleanability. Here, we present a simple method for the manufacture of robust self-cleaning ARCs. Our strategy relies on the self-assembly of a block-copolymer in combination with silica-based sol-gel chemistry and preformed TiO2 nanocrystals. The spontaneous dense packing of copolymer micelles followed by a condensation reaction results in an inverse opal-type silica morphology that is loaded with TiO2 photocatalytic hot-spots. The very low volume fraction of the inorganic network allows the optimization of the antireflecting properties of the porous ARC despite the high refractive index of the embedded photocatalytic TiO2 nanocrystals. The resulting ARCs combine high optical and self-cleaning performance and can be deposited onto flexible plastic substrates. © 2013 American Chemical Society.

  14. Self-cleaning antireflective optical coatings.

    Science.gov (United States)

    Guldin, Stefan; Kohn, Peter; Stefik, Morgan; Song, Juho; Divitini, Giorgio; Ecarla, Fanny; Ducati, Caterina; Wiesner, Ulrich; Steiner, Ullrich

    2013-01-01

    Low-cost antireflection coatings (ARCs) on large optical surfaces are an ingredient-technology for high-performance solar cells. While nanoporous thin films that meet the zero-reflectance conditions on transparent substrates can be cheaply manufactured, their suitability for outdoor applications is limited by the lack of robustness and cleanability. Here, we present a simple method for the manufacture of robust self-cleaning ARCs. Our strategy relies on the self-assembly of a block-copolymer in combination with silica-based sol-gel chemistry and preformed TiO2 nanocrystals. The spontaneous dense packing of copolymer micelles followed by a condensation reaction results in an inverse opal-type silica morphology that is loaded with TiO2 photocatalytic hot-spots. The very low volume fraction of the inorganic network allows the optimization of the antireflecting properties of the porous ARC despite the high refractive index of the embedded photocatalytic TiO2 nanocrystals. The resulting ARCs combine high optical and self-cleaning performance and can be deposited onto flexible plastic substrates.

  15. Adhesion of Antireflective Coatings in Multijunction Photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Brock, Ryan; Miller, David C.; Dauskardt, Reinhold H.

    2016-11-21

    The development of a new composite dual cantilever beam (cDCB) thin-film adhesion testing method is reported, which allows the measurement of adhesion on the fragile thin substrates used in multijunction photovoltaics. We address the adhesion of several antireflective coating systems on multijunction cells. By varying interface chemistry and morphology, we demonstrate the ensuing effects on adhesion and help to develop an understanding of how high adhesion can be achieved, as adhesion values ranging from 0.5 J/m2 to 10 J/m2 were measured. Damp Heat (85 degrees C/85% RH) was used to invoke degradation of interfacial adhesion. We show that even with germanium substrates that fracture easily, quantitative measurements of adhesion can still be made at high test yield. The cDCB test is discussed as an important new methodology, which can be broadly applied to any system that makes use of thin, brittle, or otherwise fragile substrates.

  16. A novel approach to antireflection coating using planar metamaterials

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hou-tong [Los Alamos National Laboratory; Zhou, Jiangfeng [Los Alamos National Laboratory; O' Hara, John F [Los Alamos National Laboratory; Azad, Abul K [Los Alamos National Laboratory; Chen, Frank [Los Alamos National Laboratory; Taylor, Antoinette J [Los Alamos National Laboratory

    2010-01-01

    We experimentally demonstrate a novel antireflection coating using planar metamaterials. It dramatically reduces the reflectance and enhances the transmittance over a wide range of incidence angles for both polarizations near the designed wavelength.

  17. Advanced Antireflection Coatings for High-Performance Solar Energy Applications

    Science.gov (United States)

    Pan, Noren

    2015-01-01

    Phase II objectives: Develop and refine antireflection coatings incorporating lanthanum titanate as an intermediate refractive index material; Investigate wet/dry thermal oxidation of aluminum containing semiconductor compounds as a means of forming a more transparent window layer with equal or better optical properties than its unoxidized form; Develop a fabrication process that allows integration of the oxidized window layer and maintains the necessary electrical properties for contacting the solar cell; Conduct an experimental demonstration of the best candidates for improved antireflection coatings.

  18. High gain durable anti-reflective coating with oblate voids

    Energy Technology Data Exchange (ETDEWEB)

    Maghsoodi, Sina; Brophy, Brenor L.; Colson, Thomas E.; Gonsalves, Peter R.; Abrams, Ze' ev

    2016-06-28

    Disclosed herein are single layer transparent coatings with an anti-reflective property, a hydrophobic property, and that are highly abrasion resistant. The single layer transparent coatings contain a plurality of oblate voids. At least 1% of the oblate voids are open to a surface of the single layer transparent coatings.

  19. Plasmonic and silicon spherical nanoparticle anti-reflective coatings

    OpenAIRE

    K. V. Baryshnikova; M. I. Petrov; Babicheva, V. E.; Belov, P. A.

    2015-01-01

    Over the last decade, plasmonic antireflecting nanostructures have been extensively studied to be utilized in various optical and optoelectronic systems such as lenses, solar cells, photodetectors, and others. The growing interest to all-dielectric photonics as an alternative optical technology along with plasmonics motivates us to compare antireflection properties of all-dielectric and plasmonic nanoparticle coatings based on silver and crystalline silicon. Our results of numerical simulatio...

  20. Optimization of broadband omnidirectional antireflection coatings for solar cells

    CERN Document Server

    Guo, Xia; Li, Chong; Zhou, Hongyi; Lv, Benshun; Feng, Yajie; Wang, Huaqiang; Liu, Wuming

    2015-01-01

    Broadband and omnidirectional antireflection coating is a generally effective way to improve solar cell efficiency, because the destructive interference between the reflected and input waves could maximize transmission light in the absorption layer. Several theoretical calculations have been developed to optimize the anti-reflective coating to maximize the average transmittance. However, the solar irradiances of the clear sky spectral direct beam on a receiver plane at different positions and times are variable greatly. Here we report a new theoretical calculation of anti-reflective coating with incident quantum efficiency {\\eta}in as evaluation function for practical application. The two-layer and three-layer anti-reflective coatings are optimized over {\\lambda} = [300, 1100] nm and {\\theta} = [0{\\deg}, 90{\\deg}] for cities of Quito, Beijing and Moscow. The {\\eta}in of two-layer anti-reflective coating increases by 0.26%, 1.37% and 4.24% for these 3 cities, respectively, compared with that other theoretical ...

  1. Plasmonic and silicon spherical nanoparticle anti-reflective coatings

    CERN Document Server

    Baryshnikova, K V; Babicheva, V E; Belov, P A

    2015-01-01

    Over the last decade, plasmonic antireflecting nanostructures have been extensively studied to be utilized in various optical and optoelectronic systems such as lenses, solar cells, photodetectors, and others. The growing interest to all-dielectric photonics as an alternative optical technology along with plasmonics motivates us to compare antireflection properties of all-dielectric and plasmonic nanoparticle coatings based on silver and crystalline silicon. Our results of numerical simulations for periodic arrays of spherical nanoparticles on top of amorphous silicon show that both silicon and silver nanoparticle coatings demonstrate strong anti-reflective properties in the visible spectral range. In this work, we show for the first time that blooming effect, that is zero reflection from the structure, with silicon coatings originates from the interference of electric- and magnetic-dipole responses of nanoparticles with the wave reflected from the substrate, and we refer to it as substrate-mediated Kerker ef...

  2. A novel trilayer antireflection coating using dip-coating technique

    Institute of Scientific and Technical Information of China (English)

    Jian Xu; Yi Yin; Haiming Ma; Hui Ye; Xu Liu

    2011-01-01

    We report a new structure for broadband antireflection coating by dip-coating technique,which has minimal cost and is compatible with large-scale manufacturing.The coatings are prepared by depositing SiO2 sol-gel film on a glass substrate,subsequently depositing SiO2 single-layer particle coating through electrostatic attraction,and depositing a final very thin Si02 sol-gel film to improve the mechanical strength of the whole coating structure.The refractive index of the structure changes gradually from the top to the substrate.The transmittance of a glass substrate has been experimentally found to be improved in the spectral range of 400-1400 nn and in the incidence angle range from 0° to at least 45°.The mechanical strength is immensely improved because of the additional thin Si02 sol-gel layer.The surface texture can be applied to the substrates of different materials and shapes as an add-on coating.

  3. Antireflection coatings of increased optical efficiency for the IR region

    Science.gov (United States)

    Sokolova, R. S.; Mikhailov, A. V.; Muranova, G. A.

    2005-10-01

    This paper discusses achromatic antireflection coatings of increased optical efficiency with a residual reflectance of ρave=0.1-0.3% in the spectral regions 3-5 and 8-12.5 µm for silicon, germanium, and zinc selenide. Designs are presented for such coatings of various compositions, based on operationally stable thin-film materials. The spectral characteristics of the reflectance are also shown for the coatings under consideration.

  4. Antireflection coatings for GaAs solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Alexieva, Z I; Nenova, Z S; Bakardjieva, V S; Dikov, Hr M; Milanova, M M, E-mail: alexieva@phys.bas.b [Central Laboratory of Applied Physics, Bulgarian Academy of Sciences, 59 St Petersrburg Blvd, 4000 Plovdiv (Bulgaria)

    2010-04-01

    A double-layer structure of Al{sub 2}O{sub 3} over ZrO{sub 2} film is studied. Minimization of the average weighted reflectance is carried out to optimize the thickness of the two layers in the antireflection coating. An optimal value of 2.17% for the weighted average reflection is estimated. The optimal thicknesses of the layers are 49 nm for the bottom and 45 nm for the top layer. Low temperature spin coating technique is used to deposit ZrO{sub 2} and Al{sub 2}O{sub 3} films from sol gel solutions on polished silicon wafers, GaAs multilayer heterostructures and AlGaAs/GaAs solar cells. The density of the short-circuit photocurrent increases from 25 mA.cm{sup -2} for solar cells without an antireflection coating to 36 mA.cm{sup -2} for those with a double layer coating.

  5. Antireflection coatings for GaAs solar cell applications

    Science.gov (United States)

    Alexieva, Z. I.; Nenova, Z. S.; Bakardjieva, V. S.; Milanova, M. M.; Dikov, Hr M.

    2010-04-01

    A double-layer structure of Al2O3 over ZrO2 film is studied. Minimization of the average weighted reflectance is carried out to optimize the thickness of the two layers in the antireflection coating. An optimal value of 2.17% for the weighted average reflection is estimated. The optimal thicknesses of the layers are 49 nm for the bottom and 45 nm for the top layer. Low temperature spin coating technique is used to deposit ZrO2 and Al2O3 films from sol gel solutions on polished silicon wafers, GaAs multilayer heterostructures and AlGaAs/GaAs solar cells. The density of the short-circuit photocurrent increases from 25 mA.cm-2 for solar cells without an antireflection coating to 36 mA.cm-2 for those with a double layer coating.

  6. Sol-gel derived contamination resistant antireflective coatings

    Science.gov (United States)

    Shen, Jun; Liu, Yuan; Wu, Guangming; Zhou, Bin; Zhang, Zhihua; Zhu, Yumei

    2011-02-01

    Silica-based sol-gel antireflective (AR) optical coatings are critical components for high peak power laser systems. It is well known that water vapor and volatile organic compounds in both the laser bay and target bay environments will reduce the antireflective efficiency and laser-damage resistance of the sol-gel AR coating. In this study, alkylation with organosilanes in the vapor state was investigated. Sol-gel AR coatings were vapor-phase treated with hexamethyldisilazane (HMDS) and trimethylchlorosilane (TMCS) at room temperature, and the resulting post-treated sol-gel AR coatings were tested for their resistance to contamination by a series of volatile organic compounds. Contact angle measurements were taken to discern the degree of silanization. After the vapor treatment of sol-gel AR coatings with organosilanes, the spectral performance of the coatings were analyzed by spectrophotometer, both before and after the exposure to volatile organic compounds. It is found that the coatings treated with ammonia and HMDS show a better contamination resistant capability. After being contaminated 70 hours with hexane, the transmittance of the coatings presents no obvious decrease. And the vapor treatment produces an increase in their damage threshold at 1064 nm (10ns pulse width) as compared to untreated control samples.

  7. Single and Double-Layer Antireflection Coatings on Silicon

    Science.gov (United States)

    Kavakli, Ýpek Gýrgýn; Kantarli, Kayhan

    2002-09-01

    In this study, the effect of single and double-layer thin film coatings on the reflectance spectrum of silicon surfaces has been investigated. Thin film coatings have been prepared by vacuum evaporation of the materials with suitable refractive index. Reflectance measurements in the visible and near infrared have shown that the coated samples acquire antireflection properties. Thickness and wavelength dependence of the antireflection properties of SiO, CeO2 and ZnS single-layer coatings with optical thickness of one quarter wavelength has been studied. In double-layer coatings, a thin film of SiO, CeO2 and ZnS with optical thickness of quarter wavelength were used as inner layer while a thin film of MgF2 with equal optical thickness was used as outer layer. It was shown that double-layer coatings can produce a significantly broader low reflectance region than does the single-layer coating. The results have been discussed by considering the zero reflectance conditions for the refractive index and the optical thickness of layers.

  8. Silicon Nitride Antireflection Coatings for Photovoltaic Cells

    Science.gov (United States)

    Johnson, C.; Wydeven, T.; Donohoe, K.

    1984-01-01

    Chemical-vapor deposition adapted to yield graded index of refraction. Silicon nitride deposited in layers, refractive index of which decreases with distance away from cell/coating interface. Changing index of refraction allows adjustment of spectral transmittance for wavelengths which cell is most effective at converting light to electric current. Average conversion efficiency of solar cells increased from 8.84 percent to 12.63 percent.

  9. Wide-band antireflection coatings; Breitbandige Antireflexbeschichtungen

    Energy Technology Data Exchange (ETDEWEB)

    Gombert, A.; Rommel, M. [Fraunhofer-Inst. fuer Solare Energiesysteme, Freiburg (Germany)

    1998-02-01

    In most cases, solar receivers - from solar collectors to buildings - have a transparent cover. In order to minimize the losses due to reflection, the aim is to find an AR coating which can be used for the broad bandwidth of the solar spectrum. Conventional solutions like multilayer systems with high and low refractive index layers are not suitable. The main problem is to produce layers with very low refractive indices. One solution which was investigated in the past is to synthesize layers with a low effective refractive index due to porosity; i.e. by mixing the bulk material with air on a subwavelength scale. Another possibility to achieve this mixture is given by subwave length surface-relief structures. Porous sol-gel coatings are suited for glass, subwavelength surface-relief structures can be replicated mainly in polymer materials by cheap embossing processes. (orig.) [Deutsch] Nahezu alle solaren Empfaenger sind transparent abgedeckt, z.B. durch Glascheiben. An diesen Abdeckungen wird ein Teil der einfallenden Solarstrahlung reflektiert. Diese Verluste koennen durch reflexionsmindernde Oberflaechen reduziert werden. Antireflexbeschichtungen, die z.B. fuer Brillenglaeser eingesetzt werden, eignen sich nicht fuer solare Entspiegelungen, da ihre spektrale Bandbreite nicht ausreicht. Das Hauptproblem liegt darin, dass Materialien mit sehr niedrigen Brechungsindices, wie sie fuer spektral breitbandige Antireflexbeschichtungen benoetigt werden, nicht verfuegbar sind. Der Ausweg besteht in poroesen Beschichtungen bzw. in einer Oberflaechenstrukturierung. Aufgrund des Luftanteils in der Mischung lassen sich sehr niedrige `effektive` Brechungsindices synthetisieren. Poroese Sol-Gel-Schichten eignen sich insbesondere zur Erhoehung der solaren Transmission von anorganischem Glas. Oberflaechenstrukturen sind aufgrund der Herstellbarkeit durch preisguenstige Praegeprozesse vielversprechend, finden aber derzeit ihre Anwendung ueberwiegend bei polymeren Materialien. (orig.)

  10. Ultraviolet antireflection coatings for use in silicon detector design

    Science.gov (United States)

    Hamden, Erika T.; Greer, Frank; Hoenk, Michael E.; Blacksberg, Jordana; Dickie, Matthew R.; Nikzad, Shouleh; Martin, D. Christopher; Schiminovich, David

    2011-07-01

    We report on the development of coatings for a charged-coupled device (CCD) detector optimized for use in a fixed dispersion UV spectrograph. Because of the rapidly changing index of refraction of Si, single layer broadband antireflection (AR) coatings are not suitable to increase quantum efficiency at all wavelengths of interest. Instead, we describe a creative solution that provides excellent performance over UV wavelengths. We describe progress in the development of a coated CCD detector with theoretical quantum efficiencies (QEs) of greater than 60% at wavelengths from 120 to 300nm. This high efficiency may be reached by coating a backside-illuminated, thinned, delta-doped CCD with a series of thin film AR coatings. The materials tested include MgF2 (optimized for highest performance from 120--150nm), SiO2 (150--180nm), Al2O3 (180--240nm), MgO (200--250nm), and HfO2 (240--300nm). A variety of deposition techniques were tested and a selection of coatings that minimized reflectance on a Si test wafer were applied to functional devices. We also discuss future uses and improvements, including graded and multilayer coatings.

  11. Ultraviolet antireflection coatings for use in silicon detector design

    Energy Technology Data Exchange (ETDEWEB)

    Hamden, Erika T.; Greer, Frank; Hoenk, Michael E.; Blacksberg, Jordana; Dickie, Matthew R.; Nikzad, Shouleh; Martin, D. Christopher; Schiminovich, David

    2011-07-20

    We report on the development of coatings for a charged-coupled device (CCD) detector optimized for use in a fixed dispersion UV spectrograph. Because of the rapidly changing index of refraction of Si, single layer broadband antireflection (AR) coatings are not suitable to increase quantum efficiency at all wavelengths of interest. Instead, we describe a creative solution that provides excellent performance over UV wavelengths. We describe progress in the development of a coated CCD detector with theoretical quantum efficiencies (QEs) of greater than 60% at wavelengths from 120 to 300 nm. This high efficiency may be reached by coating a backside-illuminated, thinned, delta-doped CCD with a series of thin film AR coatings. The materials tested include MgF{sub 2} (optimized for highest performance from 120-150 nm), SiO{sub 2} (150-180 nm), Al{sub 2}O{sub 3} (180-240 nm), MgO (200-250 nm), and HfO{sub 2} (240-300 nm). A variety of deposition techniques were tested and a selection of coatings that minimized reflectance on a Si test wafer were applied to functional devices. We also discuss future uses and improvements, including graded and multilayer coatings.

  12. Wide spectral range characterization of antireflective coatings and their optimization

    Science.gov (United States)

    Franta, Daniel; Nečas, David; Ohlídal, Ivan; Jankuj, Jiří

    2015-09-01

    Development of antireflective coatings realized by thin film systems requires their characterization and optimization of their properties. Functional properties of such interference devices are determined by optical constants and thicknesses of the individual films and various defects taking place in these systems. In optics industry the characterization of the films is mostly performed in a relatively narrow spectral range using simple dispersion models and, moreover, the defects are not taken into account at all. This manner of characterization fails if applied to real-world non-ideal thin film systems because the measured data do not contain sufficient information about all the parameters describing the system including imperfections. Reliable characterization requires the following changes: extension of spectral range of measurements, combination of spectrophotometry and ellipsometry, utilization of physically correct dispersion models (Kramers-Kronig consistency, sum rules), inclusion of structural defects instrument imperfection into the models and simultaneous processing of all experimental data. This enables us to remove or reduce a correlation among the parameters searched so that correct and sufficiently precise determination of parameter values is achieved. Since the presence and properties of the defects are difficult to control independently by tuning of the deposition conditions, the optimization does not in general involve the elimination of defects. Instead they are taken into account in the design of the film systems. The outlined approach is demonstrated on the characterization and optimization of ultraviolet antireflective coating formed by double layer of Al2O3 and MgF2 deposited on fused silica.

  13. Protective infrared antireflection coating based on sputtered germanium carbide

    Science.gov (United States)

    Gibson, Des; Waddell, Ewan; Placido, Frank

    2011-09-01

    This paper describes optical, durablility and environmental performance of a germanium carbide based durable antireflection coating. The coating has been demonstrated on germanium and zinc selenide infra-red material however is applicable to other materials such as zinc sulphide. The material is deposited using a novel reactive closed field magnetron sputtering technique, offering significant advantages over conventional evaporation processes for germanium carbide such as plasma enhanced chemical vapour deposition. The sputtering process is "cold", making it suitable for use on a wide range of substrates. Moreover, the drum format provide more efficient loading for high throughput production. The use of the closed field and unbalanced magnetrons creates a magnetic confinement that extends the electron mean free path leading to high ion current densities. The combination of high current densities with ion energies in the range ~30eV creates optimum thin film growth conditions. As a result the films are dense, spectrally stable, supersmooth and low stress. Films incorporate low hydrogen content resulting in minimal C-H absorption bands within critical infra-red passbands such as 3 to 5um and 8 to 12um. Tuning of germanium carbide (Ge(1-x)Cx) film refractive index from pure germanium (refractive index 4) to pure germanium carbide (refractive index 1.8) will be demonstrated. Use of film grading to achieve single and dual band anti-reflection performance will be shown. Environmental and durability levels are shown to be suitable for use in harsh external environments.

  14. Improved antireflection coated microspheres for biological applications of optical tweezers

    Science.gov (United States)

    Ferro, Valentina; Sonnberger, Aaron; Abdosamadi, Mohammad K.; McDonald, Craig; Schäffer, Erik; McGloin, David

    2016-09-01

    The success of optical tweezers in cellular biology1 is in part due to the wide range of forces that can be applied, from femto- to hundreds of pico-Newtons; nevertheless extending the range of applicable forces to the nanoNewton regime opens access to a new set of phenomena that currently lie beyond optical manipulation. A successful approach to overcome the conventional limits on trapping forces involves the optimization of the trapped probes. Jannasch et al.2 demonstrated that an anti-reflective shell of nanoporous titanium dioxide (aTiO2, nshell = 1.75) on a core particle made out of titanium dioxide in the anatase phase (cTiO2, ncore = 2.3) results in trappable microspheres capable to reach forces above 1 nN. Here we present how the technique can be further improved by coating the high refractive index microspheres with an additional anti-reflective shell made out of silica (SiO2). This external shell not only improves the trap stability for microspheres of different sizes, but also enables the use of functionalization techniques already established for commercial silica beads in biological experiments. We are also investigating the use of these new microspheres as probes to measure adhesion forces between intercellular adhesion molecule 1 (ICAM-1) and lymphocyte function-associated antigen 1 (LFA-1) in effector T-Cells and will present preliminary results comparing standard and high-index beads.

  15. Antireflection coatings on plastics deposited by plasma polymerization process

    Indian Academy of Sciences (India)

    K M K Srivatsa; M Bera; A Basu; T K Bhattacharya

    2008-08-01

    Antireflection coatings (ARCs) are deposited on the surfaces of optical elements like spectacle lenses to increase light transmission and improve their performance. In the ophthalmic industry, plastic lenses are rapidly displacing glass lenses due to several advantageous features. However, the deposition of ARCs on plastic lenses is a challenging task, because the plastic surface needs treatment for adhesion improvement and surface hardening before depositing the ARC. This surface treatment is usually done in a multi-stage process—exposure to energetic radiations, followed by deposition of a carbonyl hard coating by spin or dip coating processes, UV curing, etc. However, this treatment can also be done by plasma processes. Moreover, the plasma polymerization process allows deposition of optical films at room temperature, essential for plastics. The energetic ions in plasma processes provide similar effects as in ion assisted physical deposition processes to produce hard coatings, without requiring sophisticated ion sources. The plasma polymerization process is more economical than ion-assisted physical vapour deposition processes as regards equipment and source materials and is more cost-effective, enabling the surface treatment and deposition of the ARC in the same deposition system in a single run by varying the system parameters at each step. Since published results of the plasma polymerization processes developed abroad are rather sketchy and the techniques are mostly veiled in commercial secrecy, innovative and indigenous plasma-based techniques have been developed in this work for depositing the complete ARCs on plastic substrates.

  16. Optimization of multilayer antireflection coating for photovoltaic applications

    Science.gov (United States)

    Sikder, Urmita; Zaman, Mohammad Asif

    2016-05-01

    Multilayer antireflection coating (ARC) for photovoltaics is optimized using Differential Evolution (DE) algorithm. A general transfer-matrix based mathematical formulation is used for evaluating reflection spectra of the system. Exact and complete values of refractive indices are used in the analysis to provide higher accuracy of the results. The proposed optimization method takes into account the solar irradiance spectra, absorption characteristics of semiconductors and angle of incidence to maximize efficiency. This method is found to reduce the average reflectance for a wide range of angles of incidence. The proposed method is used to design ARC for silicon solar cell and a multi-junction AlGaAs/GaAs/Ge solar cell. Finally, comparative analysis of different ARC designs is provided in terms of corresponding solar cell characteristics.

  17. Adhesion of Antireflective Coatings in Multijunction Photovoltaics: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Brock, Ryan; Dauskardt, Reinhold H.; Miller, David C.

    2016-06-16

    The development of a new composite dual cantilever beam (cDCB) thin-film adhesion testing method is reported, which allows the measurement of adhesion on the fragile thin substrates used in multijunction photovoltaics. We address the adhesion of several antireflective coating systems on multijunction cells. By varying interface chemistry and morphology, we demonstrate the ensuing effects on adhesion and help to develop an understanding of how high adhesion can be achieved, as adhesion values ranging from 0.5 J/m2 to 10 J/m2 were measured. Damp Heat (85 degrees C/85% RH) was used to invoke degradation of interfacial adhesion. We show that even with germanium substrates that fracture easily, quantitative measurements of adhesion can still be made at high test yield. The cDCB test is discussed as an important new methodology, which can be broadly applied to any system that makes use of thin, brittle, or otherwise fragile substrates.

  18. Design Multilayer Antireflection Coatings for Terrestrial Solar Cells

    Directory of Open Access Journals (Sweden)

    Feng Zhan

    2014-01-01

    Full Text Available In order to analyze the influence of methods to design antireflection coatings (ARCs on reflectivity of broadband solar cells, we provide detailed analyses about the ARC coupled with a window layer and the refractive index dispersion effect of each layer. By multidimensional matrix data simulation, two methods were employed to measure the composite reflection of a SiO2/ZnS double-layer ARC within the spectral ranges of 300–870 nm (dual junction and 300–1850 nm (triple junction under AM1.5 solar radiation. A comparison study, between the results obtained from the commonly used weighted average reflectance method (WAR and that from the introduced effective average reflectance method (EAR, shows that the optimization of ARC by EAR method is convenient and feasible.

  19. Multilayer Antireflection Coating for Triple Junction Solar Cells

    Institute of Scientific and Technical Information of China (English)

    ZHAN Feng; WANG Hai-Li; HE Ji-Fang; WANG Juan; HUANG She-Song; NI Hai-Qiao; NIU Zhi-Chuan

    2011-01-01

    @@ According to the theory of optical films, we simulate the reflectivity of antireflection coatings(ARCS)for solar cells of Gao.51no.5P/GaAs/Ge based on an optical transfer matrix.In order to provide sufficient consideration of the refractive index dispersion effect of multilayer ARCS, we use multi-dimensional matrix data for reliable simulation.After the reflection curves are obtained, the effective average reflectance Re is introduced to optimize the film system by minimizing Re.Optimization of single layer(A1203), double layer(MgF2/ZnS)and triple layer(MgF2/A12O3/ZnS)ARCS is realized by using this method for space and terrestrial applications.Effects of these ARCS are compared after optimization.These theoretical parameters can be used to guide experiments.%According to the theory of optical films, we simulate the reflectivity of antireflection coatings (ARCs) for solar cells of Ga0.5In0.5P/GaAs/Ge based on an optical transfer matrix. In order to provide sufficient consideration of the refractive index dispersion effect of multilayer ARCs, we use multi-dimensional matrix data for reliable simulation. After the reflection curves are obtained, the effective average reflectance Re is introduced to optimize the film system by minimizing Re. Optimization of single layer (Al2O3), double layer (MgF2/ZnS) and triple layer (MgF2/Al2O3/ZnS) ARCs is realized by using this method for space and terrestrial applications. Effects of these ARCs are compared after optimization. These theoretical parameters can be used to guide experiments.

  20. Durability testing of antireflection coatings for solar applications

    Science.gov (United States)

    Jorgensen, Gary J.; Brunold, Stefan; Koehl, Michael; Nostell, Per; Oversloot, Henk; Roos, Arne

    1999-10-01

    Antireflection (AR) coatings can be incorporated into highly transmitting glazings that, depending upon their cost, performance, and durability of optical properties, can be economically viable in solar collectors, agricultural greenhouses, and PV systems. A number of AR-coated glazings have been prepared under the auspices of the International Energy Agency Working Group on Durability of Materials for Solar Thermal Collectors. The AR coatings are of two types, including (1) various sol-gels applied to glass and (2) an embossed treatment of sheet acrylic. Typically, for unweathered glazings, a 4 - 5% increase in solar-weighted transmittance has been achieved. For AR-coated glass, reflectance values as low as 0.5% - 0.7% at selected wavelengths (680 - 720 nm) were obtained. To determine the durability of the hemispherical transmittance, several collaborating countries are testing these materials both outdoors and in accelerated weathering chambers. All materials exposed outdoors are affixed to mini-collector boxes to simulate flat-plate collector conditions. Results for candidate AR coatings weathered at geographically disperse outdoor test sites exhibit changes in spectral transmittance primarily in the high visible range (600 - 700 nm). Accelerated testing at measured levels of simulated solar irradiance, and at different constant levels of temperature and relative humidity have been performed in different countries. Parallel testing with different levels of laboratory-controlled relevant stress factors permits the time-dependent performance of these materials to be compared with measured results from in-service outdoor exposure conditions. Coating adhesion and performance loss resulting from dirt and dust retention are also discussed.

  1. Development of Advanced Anti-Reflection Coatings for High Performance Solar Energy Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — MicroLink and its subcontractor Magnolia Solar will develop and demonstrate advanced anti-reflection coating (ARC) designs that will provide a better broadband and...

  2. Development of Advanced Anti-Reflection Coatings for High Performance Solar Energy Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — MicroLink Devices will increase the efficiency of multi-junction solar cells by designing and demonstrating advanced anti-reflection coatings (ARCs) that will...

  3. Nano-Enabled Low-Cost High-Performance UV Anti-Reflection Coatings Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this program, Agiltron and the groups of Professors Rubner and Cohen at MIT propose a novel nano-porous coating for next generation NASA UV anti-reflection (AR)...

  4. Antireflection coating standards of ophthalmic resin lens materials

    Science.gov (United States)

    Porden, Mark

    1991-12-01

    Current estimates of the percentage of anti-reflection coated lenses verses uncoated in the market today range from 3% in the United States (US.), to 60% in Europe, to 80% in Japan. Currently upwards of 80% of all prescription eyewear lenses dispensed are resin. Glass lenses lose market share yearly, as scratch resistant coatings on resin lenses are improved. Photochromic resin materials are also improving and will shortly equal the performance of glass photockromics. Until recently, the performance characteristics of ophthalmic lenses were divided into two schools. In Europe, the emphasis was on keeping the reflections to an absolute minimum, while in the Asian market the emphasis was on producing a lens, which had exceptional scratch resistance. A typical European lens may average .4% reflection across the visible spectrum (400 to 700 urn.), while the Asian lenses averaged in the 1.5% range. The growth ofAR coating in the U.S. 80 million pair a year total ophthalmic market has been lagging foreign markets for several reasons.

  5. Sprayed and Spin-Coated Multilayer Antireflection Coating Films for Nonvacuum Processed Crystalline Silicon Solar Cells

    OpenAIRE

    Abdullah Uzum; Masashi Kuriyama; Hiroyuki Kanda; Yutaka Kimura; Kenji Tanimoto; Hidehito Fukui; Taichiro Izumi; Tomitaro Harada; Seigo Ito

    2017-01-01

    Using the simple and cost-effective methods, spin-coated ZrO2-polymer composite/spray-deposited TiO2-compact multilayer antireflection coating film was introduced. With a single TiO2-compact film on the surface of a crystalline silicon wafer, 5.3% average reflectance (the reflectance average between the wavelengths of 300 nm and 1100 nm) was observed. Reflectance decreased further down to 3.3% after forming spin-coated ZrO2 on the spray-deposited TiO2-compact film. Silicon solar cells were fa...

  6. INKJET PRINTING OF ALUMOOXIDE SOL FOR DEPOSITION OF ANTIREFLECTING COATINGS

    Directory of Open Access Journals (Sweden)

    E. A. Eremeeva

    2017-01-01

    Full Text Available Subject of Research. This work describes for the first time the formation of antireflective coating on the base of boehmite phase of AlOOH with low refractive index (1.35 by inkjet printing on the nonporous substrate. This method gives the possibility to increase the contrast of colorful interfering images by 32% obtaining by inkjet printing of titanium dioxide sol. The usage of this technology enables to obtain patterns with wide viewing angle and makes them highly stable. Methods. Traditional sol-gel method with peptizing agents and heating for 90oC was applied for sol synthesis. Then the mixture was under sonic treatment for the obtaining of viscous sol. The viscosity was determined by Brookfield HA/HB viscometer, and the surface tension by Kyowa DY-700 tensiometer. Aluminum oxide ink was deposited on polished slides (26×76 mm2, Paul Marienfeld, Germany, over titanium oxide layer. To print titania ink, we use a desktop office printer Canon Pixma IP 2840 and Dimatix DMP-2831. The thickness of an inkjet AlOOH layer after drying in the air and removal of the solvents did not exceed 150 nm with an RI not less than 1.35 in the entire visible range. Results. The stable colloidal ink was obtained for the first time on the base of aluminum oxide matrix with neutral pH. The rheology was regulated by controlling parameters of sol-gel method in the system of aqueous titanium dioxide sol and by adding ethanol that affects the charge of double electrical layer of disperse phase. The controllable coalesce of drops enables to apply antireflection coating within the thickness accuracy of 10 nm. The morphology of particles and the topology of printed structures were analyzed by optical, scanning electron and atomic-force microscopes. Practical Relevance. We have proposed the approach to obtain colorful, interference patterns using two types of high refractive inks with different refractive indexes. The inkjet printing method opens new opportunities for

  7. Quantitative adhesion characterization of antireflective coatings in multijunction photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Brock, Ryan; Rewari, Raunaq; Novoa, Fernando D.; Hebert, Peter; Ermer, James; Miller, David C.; Dauskardt, Reinhold H.

    2016-08-01

    We discuss the development of a new composite dual cantilever beam (cDCB) thin-film adhesion testing method, which enables the quantitative measurement of adhesion on the thin and fragile substrates used in multijunction photovoltaics. In particular, we address the adhesion of several 2- and 3-layer antireflective coating systems on multijunction cells. By varying interface chemistry and morphology through processing, we demonstrate the marked effects on adhesion and help to develop an understanding of how high adhesion can be achieved, as adhesion values ranging from 0.5 J/m2 to 10 J/m2 were measured. Damp heat (85 degrees C/85% RH) was used to invoke degradation of interfacial adhesion. We demonstrate that even with germanium substrates that fracture relatively easily, quantitative measurements of adhesion can be made at high test yield. The cDCB test is discussed as an important new methodology, which can be broadly applied to any system that makes use of thin, brittle, or otherwise fragile substrates.

  8. Anti-reflective and anti-soiling coatings with self-cleaning properties

    Energy Technology Data Exchange (ETDEWEB)

    Nair, Vinod; Brophy, Brenor L.

    2016-10-04

    Disclosed herein is a coated glass element including a glass component and a coating adhered to the glass component through siloxane linkages, the coating having at least one of an anti-reflective property, a high abrasion resistance property and a hydrophobic property, wherein the coating comprises a dried gel formed from at least one hydrolyzed alkoxysilane-based sol and at least one hydrolyzed organosilane-based sol.

  9. Sprayed and Spin-Coated Multilayer Antireflection Coating Films for Nonvacuum Processed Crystalline Silicon Solar Cells

    Directory of Open Access Journals (Sweden)

    Abdullah Uzum

    2017-01-01

    Full Text Available Using the simple and cost-effective methods, spin-coated ZrO2-polymer composite/spray-deposited TiO2-compact multilayer antireflection coating film was introduced. With a single TiO2-compact film on the surface of a crystalline silicon wafer, 5.3% average reflectance (the reflectance average between the wavelengths of 300 nm and 1100 nm was observed. Reflectance decreased further down to 3.3% after forming spin-coated ZrO2 on the spray-deposited TiO2-compact film. Silicon solar cells were fabricated using CZ-Si p-type wafers in three sets: (1 without antireflection coating (ARC layer, (2 with TiO2-compact ARC film, and (3 with ZrO2-polymer composite/TiO2-compact multilayer ARC film. Conversion efficiency of the cells improved by a factor of 0.8% (from 15.19% to 15.88% owing to the multilayer ARC. Jsc was improved further by 2 mA cm−2 (from 35.3 mA cm−2 to 37.2 mA cm−2 when compared with a single TiO2-compact ARC.

  10. Design of wideband graded-index antireflection coatings at oblique light incidence

    Institute of Scientific and Technical Information of China (English)

    Zhang Jun-Chao; Fang Ming; Jin Yun-Xia; He Hong-Bo

    2012-01-01

    We suggest a design method of graded-refractive-index (GRIN) antireflection (AR) coating for s-polarized or ppolarized light at off-normal incidence.The spectrum characteristic of the designed antireflection coating with a quintic effective refractive-index profile for a given state of polarization has been discussed.In addition,the genetic algorithm was used to optimize the refractive index profile of the GRIN antireflection for reducing the mean reflectance of s- and p-polarizations.The average reflectance loss was reduced to only 0.04% by applying optimized GRIN AR coatings onto BK7 glass over the wavelength range from 400 to 800 nm at the incident angle of θ0 =70°.

  11. Anti-reflective and anti-soiling coatings for self-cleaning properties

    Energy Technology Data Exchange (ETDEWEB)

    Brophy, Brenor L.; Nair, Vinod; Dave, Bakul Champaklal

    2016-05-31

    The disclosure discloses abrasion resistant, persistently hydrophobic and oleophobic, anti-reflective and anti-soiling coatings for glass. The coatings described herein have wide application, including for example the front cover glass of solar modules. Methods of applying the coatings using various apparatus are disclosed. Methods for using the coatings in solar energy generation plants to achieve greater energy yield and reduced operations costs are disclosed. Coating materials are formed by combinations of hydrolyzed silane-base precursors through sol-gel processes. Several methods of synthesis and formulation of coating materials are disclosed.

  12. Antireflective coatings on Fresnel lenses by spin-coating of solid silica nanoparticles.

    Science.gov (United States)

    Zhou, Gang; He, Junhui

    2013-08-01

    Antireflective (AR) coatings were fabricated from solid silica nanoparticles (SNPs) of ca. 16 nm in size on Fresnel lenses via one-step spin coating without any high temperature treatment. Transmission electron microscopy was used to observe the morphology and structure of the SNPs. Transmission spectra were recorded on a UV-vis-NIR spectrophotometer. The results indicated that Fresnel lenses covered with the SNPs coatings were much more transparent than the uncoated Fresnel lens. The maximum transmittance of the coated Fresnel lenses reached as high as 99.8%, whereas that of the uncoated Fresnel lens is only 94.3%. Surface wettability was studied by a contact angle/interface system, and the results indicated that the coatings on Fresnel lenses were more hydrophilic than the uncoated Fresnel lens. The surface morphologies and structures of the coatings were examined by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The mechanical robustness of the coatings was examined by pencil scratch tests and attenuated total reflection infrared spectroscopy (ATR-IR).

  13. Design of multi-layer anti-reflection coating for terrestrial solar panel glass

    Indian Academy of Sciences (India)

    B GEETHA PRIYADARSHINI; A K SHARMA

    2016-06-01

    To date, there is no ideal anti-reflection (AR) coating available on solar glass which can effectively transmit the incident light within the visible wavelength range. However, there is a need to develop multifunctional coatingwith superior anti-reflection properties and self-cleaning ability meant to be used for solar glass panels. In spite of self-cleaning ability of materials like TiO2 and ZnO, these coatings on glass substrate have tendency to reduce lighttransmission due to their high refractive indices than glass. Thus, to infuse the anti-reflective property, a low refractive index, SiO$_2$ layer needs to be used in conjunction with TiO$_2$ and ZnO layers. In such case, the optimization ofindividual layer thickness is crucial to achieve maximum transmittance of the visible light. In the present study, we propose an omni-directional anti-reflection coating design for the visible spectral wavelength range of 400–700 nm,where the maximum intensity of light is converted into electrical energy. Herein, we employ the quarter wavelength criteria using SiO$_2$, TiO$_2$ and ZnO to design the coating composed of single, double and triple layers. The thicknessof individual layers was optimized for maximum light transmittance using essential Mcleod simulation software to produce destructive interference between reflected waves and constructive interference between transmitted waves.

  14. An in-situ monitoring technique for optimizing antireflection coatings using a monolithic integrated photodetector

    DEFF Research Database (Denmark)

    Saini, Vikram; Yvind, Kresten; Larsson, David

    2006-01-01

    A very low reflectivity of the order of 10-4 is demonstrated for dual-layer anti-reflection coatings on normal facet semiconductor lasers, by integrated in situ monitoring. The method has been tested on three and eight quantum-well InGaAsP ridge lasers that consist of a gain section and an integr...

  15. Sol-gel broadband antireflective coatings for advanced laser-glass amplifiers

    Science.gov (United States)

    Floch, Herve G.; Belleville, Philippe F.; Pegon, Philippe M.

    1994-10-01

    The cost of a large laser system is a strong function of the overall electrical to final photon efficiency. To improve the stored energy and therefore the pumping efficiency of sophisticated and costly laser-glass amplifiers, we have developed a novel two-layer broadband antireflective coating for the blast-shield component. The blast-shield is an optic placed between the flashlamps and the laser disk amplifiers to prevent damage of laser disks by possible explosion of a flashlamp. The sol-gel antireflective coating was dip-coated at room temperature onto 8-cm diameter glass samples. The coating basically consisted of a halfwave- thick high-index material such as ZrO2-PVP (PolyVinyl Pyrrolidone) and a quarterwave- thick low-index material such as SiO2-siloxane. To improve the abrasion resistance of the coated part, a lubricating and water-repellent material was applied as a very thin overcoat. In addition to a 6.5 to 7.2% transmission gain over the spectrum of interest, the coating was moderately abrasion resistant and chemically durable. Flashlamp-induced damage to the antireflective coating for 1000 glow discharges at 10 to 12 J/cm2 were minimal and similar to uncoated parts.

  16. Anti-reflection coatings applied by acid-leaching process. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Pastirik, E.

    1980-09-01

    The Magicote C process developed by S.M. Thompsen was evaluated for use in applying an antireflective coating to the cover plates of solar cell panels. The process uses a fluosilicic acid solution supersaturated with silica at elevated temperature to selectively attack the surface of soda-lime glass cover plates and alter the physical and chemical composition of a thin layer of glass. The altered glass layer constitutes an antireflective coating. The process produces coatings of excellent optical quality which possess outstanding resistance to soiling and staining. The coatings produced are not resistant to mechanical abrasion and are attacked to some extent by glass cleansers. Control of the filming process was found to be difficult.

  17. Characterization of single layer anti-reflective coatings for bolometer-based rare event searches

    CERN Document Server

    Hansen, E V

    2016-01-01

    A photon signal added to the existing phonon signal can powerfully reduce backgrounds for bolometer-based rare event searches. Anti-reflective coatings can significantly increase the performance of the secondary light sensing bolometer in these experiments. Coatings of SiO2, HfO2, and TiO2 on Ge and Si were fabricated and characterized at room temperature and all angles of incidence.

  18. Antireflective Coatings: Conventional Stacking Layers and Ultrathin Plasmonic Metasurfaces, A Mini-Review

    Directory of Open Access Journals (Sweden)

    Mehdi Keshavarz Hedayati

    2016-06-01

    Full Text Available Reduction of unwanted light reflection from a surface of a substance is very essential for improvement of the performance of optical and photonic devices. Antireflective coatings (ARCs made of single or stacking layers of dielectrics, nano/microstructures or a mixture of both are the conventional design geometry for suppression of reflection. Recent progress in theoretical nanophotonics and nanofabrication has enabled more flexibility in design and fabrication of miniaturized coatings which has in turn advanced the field of ARCs considerably. In particular, the emergence of plasmonic and metasurfaces allows for the realization of broadband and angular-insensitive ARC coatings at an order of magnitude thinner than the operational wavelengths. In this review, a short overview of the development of ARCs, with particular attention paid to the state-of-the-art plasmonic- and metasurface-based antireflective surfaces, is presented.

  19. Stability of SiNX/SiNX double stack antireflection coating for single crystalline silicon solar cells

    Science.gov (United States)

    Lee, Youngseok; Gong, Daeyeong; Balaji, Nagarajan; Lee, Youn-Jung; Yi, Junsin

    2012-01-01

    Double stack antireflection coatings have significant advantages over single-layer antireflection coatings due to their broad-range coverage of the solar spectrum. A solar cell with 60-nm/20-nm SiNX:H double stack coatings has 17.8% efficiency, while that with a 80-nm SiNX:H single coating has 17.2% efficiency. The improvement of the efficiency is due to the effect of better passivation and better antireflection of the double stack antireflection coating. It is important that SiNX:H films have strong resistance against stress factors since they are used as antireflective coating for solar cells. However, the tolerance of SiNX:H films to external stresses has never been studied. In this paper, the stability of SiNX:H films prepared by a plasma-enhanced chemical vapor deposition system is studied. The stability tests are conducted using various forms of stress, such as prolonged thermal cycle, humidity, and UV exposure. The heat and damp test was conducted for 100 h, maintaining humidity at 85% and applying thermal cycles of rapidly changing temperatures from -20°C to 85°C over 5 h. UV exposure was conducted for 50 h using a 180-W UV lamp. This confirmed that the double stack antireflection coating is stable against external stress.

  20. Scale-up of Nano-Engineered Anti-Reflection Coating Process for Large Plastic Optics Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In a recently completed NASA SBIR program, Agiltron and the Massachusetts Institute of Technology developed a novel nanoporous UV anti-reflection coating technology...

  1. Global sensitivity analysis of bandpass and antireflection coating manufacturing by numerical space filling designs.

    Science.gov (United States)

    Vasseur, Olivier; Cathelinaud, Michel; Claeys-Bruno, Magalie; Sergent, Michelle

    2011-03-20

    We present the effectiveness of global sensitivity analyses of optical coatings manufacturing to assess the robustness of filters by computer experiments. The most critical interactions of layers are determined for a 29 quarter-wave layer bandpass filter and for an antireflection coating with eight non-quarter-wave layers. Two monitoring techniques with the associated production performances are considered, and their influence on the interactions classification is discussed. Global sensitivity analyses by numerical space filling designs give clues to improve filter manufacturing against error effects and to assess the potential robustness of the coatings.

  2. UV testing of solar cells: Effects of antireflective coating, prior irradiation, and UV source

    Science.gov (United States)

    Meulenberg, A.

    1993-01-01

    Short-circuit current degradation of electron irradiated double-layer antireflective-coated cells after 3000 hours ultraviolet (UV) exposure exceeds 3 percent; extrapolation of the data to 10(exp 5) hours (11.4 yrs.) gives a degradation that exceeds 10 percent. Significant qualitative and quantitative differences in degradation were observed in cells with double- and single-layer antireflective coatings. The effects of UV-source age were observed and corrections were made to the data. An additional degradation mechanism was identified that occurs only in previously electron-irradiated solar cells since identical unirradiated cells degrade to only 6 +/- 3 percent when extrapolated 10(exp 5) hours of UV illumination.

  3. UV testing of solar cells: Effects of antireflective coating, prior irradiation, and UV source

    Science.gov (United States)

    Meulenberg, A.

    1993-05-01

    Short-circuit current degradation of electron irradiated double-layer antireflective-coated cells after 3000 hours ultraviolet (UV) exposure exceeds 3 percent; extrapolation of the data to 10(exp 5) hours (11.4 yrs.) gives a degradation that exceeds 10 percent. Significant qualitative and quantitative differences in degradation were observed in cells with double- and single-layer antireflective coatings. The effects of UV-source age were observed and corrections were made to the data. An additional degradation mechanism was identified that occurs only in previously electron-irradiated solar cells since identical unirradiated cells degrade to only 6 +/- 3 percent when extrapolated 10(exp 5) hours of UV illumination.

  4. Combined Effects of Pyramid-Like Structures and Antireflection Coating on Si Solar Cell Efficiency.

    Science.gov (United States)

    Cho, Chanseob; Oh, Junghwa; Lee, Byeungleul; Kim, Bonghwan

    2015-10-01

    We developed a novel process for synthesizing Si solar cells with improved efficiencies. The process involved the formation of pyramid-like structures on the Si substrate and the deposition and subsequent thermal annealing of an antireflection coating. The process consisted of three main stages. First, pyramid-like structures were textured on the Si substrate by reactive ion etching and subsequently etched using a mixture of HF, HNO3, and deionized water for 300 s. Next, an antireflection coating was deposited on the substrate and was subsequently thermally annealed in a furnace in a N2 atmosphere. After the annealing process, the minority carrier lifetime increased by approximately 40 μs. Further, because of the increase in the minority carrier lifetime and the uniform doping of the substrate, the leakage current decreased. As a result, the efficiency of resulting solar cell increased to 17.24%, in contrast to that of the reference cell, which was only 15.89%. Thus, uniform doping and the thermal annealing of the antireflective coating improved solar cell efficiency.

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

    Science.gov (United States)

    Hollahan, J. R.; Wydeven, T.

    1975-01-01

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

  6. Characterization of 1064nm laser-induced damage on antireflection coatings grown by atomic layer deposition

    Science.gov (United States)

    Liu, Zhichao; Wei, Yaowei; Chen, Songlin; Luo, Jin; Ma, Ping

    2011-12-01

    Damage tests were carried out to measure the laser resistance of Al2O3/TiO2 and Al2O3/HfO2 antireflection coatings at 1064nm grown by atomic layer deposition (ALD). The S-on-1 and R-on-1 damage results are given. It's interesting to find that ALD coatings damage performance seems closed to those grown by conventional e-beam evaporation process. For Al2O3/TiO2 coatings, the grown temperature will impact the damage resistance of thin films. Crystallization of TiO2 layer at higher temperature could play an importance role as absorption defects that reduced the LIDT of coatings. In addition, it is found that using inorganic compound instead of organic compound as precursors for ALD process can effective prevent residual carbon in films and will increase the LIDT of coatings.

  7. Stress compensation with antireflection coatings for ultrafast laser applications: from theory to practice.

    Science.gov (United States)

    Amotchkina, Tatiana; Trubetskov, Michael K; Pervak, Yurij; Veisz, Laszlo; Pervak, Vladimir

    2014-12-01

    Each complicated coating, in particular, a dispersive mirror consists of dozens of layers. Thin films layers have mechanical stresses. After summing up stresses from all layers, the resulting stress is high enough to bend even a relatively thick substrate. To avoid this effect we suggest depositing an antireflection coating (AR) at the back-side of the substrate which together with suppression of unwanted reflections from the back side will also compensate this stress. We demonstrate unique, extremely thick and sophisticated AR coating consisting of 71 layers with the total physical thickness of 7.5 µm. This AR coating completely compensates stress from the dispersive mirror coated on the front side and minimizes unwanted reflections.

  8. UV anti-reflection coatings for use in silicon detector design

    CERN Document Server

    Hamden, Erika T; Hoenk, Michael E; Blacksberg, Jordana; Dickie, Matthew R; Nikzad, Shouleh; Martin, Christopher D; Schiminovich, David

    2011-01-01

    We report on the development of coatings for a CCD detector optimized for use in a fixed dispersion UV spectrograph. Due to the rapidly changing index of refraction of Si, single layer broadband anti-reflection coatings are not suitable to increase quantum efficiency at all wavelengths of interest. Instead, we describe a creative solution that provides excellent performance over UV wavelengths. We describe progress in the development of a CCD detector with theoretical quantum efficiencies (QE) of greater than 60% at wavelengths from 120 to 300nm. This high efficiency may be reached by coating a backside illuminated, thinned, delta-doped CCD with a series of thin film anti-reflection coatings. The materials tested include MgF2 (optimized for highest performance from 120-150nm), SiO2 (150-180nm), Al2O3(180-240nm), MgO (200-250nm), and HfO2 (240-300nm). A variety of deposition techniques were tested and a selection of coatings which minimized reflectance on a Si test wafer were applied to live devices. We also d...

  9. Performance of "Moth Eye" Anti-Reflective Coatings for Solar Cell Applications

    Energy Technology Data Exchange (ETDEWEB)

    Clark, E.; Kane, M.; Jiang, P.

    2011-03-14

    An inexpensive, effective anti-reflective coating (ARC) has been developed at the University of Florida to significantly enhance the absorption of light by silicon in solar cells. This coating has nano-scale features, and its microstructure mimics that of various night active insects (e.g. a moth's eye). It is a square array of pillars, each about 700 nm high and having a diameter of about 300 nm. Samples of silicon having this coating were exposed either to various combinations of either elevated temperature and humidity or to gamma irradiation ({sup 60}Co) at the Savannah River National Laboratory, or to a broad spectrum ultraviolet light and to a 532 nm laser light at the University of Florida. The anti-reflective properties of the coatings were unaffected by any of these environmental stresses, and the microstructure of the coating was also unaffected. In fact, the reflectivity of the gamma irradiated ARC became lower (advantageous for solar cell applications) at wavelengths between 400 and 1000 nm. These results show that this coating is robust and should be tested in actual systems exposed to either weather or a space environment. Structural details of the ARCs were studied to optimize their performance. Square arrays performed better than hexagonal arrays - the natural moth-eye coating is indeed a square array. The optimal depth of the templated nanopillars in the ARC was investigated. A wet etching technology for ARC formation was developed that would be less expensive and much faster than dry etching. Theoretical modeling revealed that dimple arrays should perform better than nipple arrays. A method of fabricating both dimple and nipple arrays having the same length was developed, and the dimple arrays performed better than the nipple arrays, in agreement with the modeling. The commercial viability of the technology is quite feasible, since the technology is scalable and inexpensive. This technology is also compatible with current industrial

  10. Atomic Layer Deposition of Chemical Passivation Layers and High Performance Anti-Reflection Coatings on Back-Illuminated Detectors

    Science.gov (United States)

    Hoenk, Michael E. (Inventor); Greer, Frank (Inventor); Nikzad, Shouleh (Inventor)

    2014-01-01

    A back-illuminated silicon photodetector has a layer of Al2O3 deposited on a silicon oxide surface that receives electromagnetic radiation to be detected. The Al2O3 layer has an antireflection coating deposited thereon. The Al2O3 layer provides a chemically resistant separation layer between the silicon oxide surface and the antireflection coating. The Al2O3 layer is thin enough that it is optically innocuous. Under deep ultraviolet radiation, the silicon oxide layer and the antireflection coating do not interact chemically. In one embodiment, the silicon photodetector has a delta-doped layer near (within a few nanometers of) the silicon oxide surface. The Al2O3 layer is expected to provide similar protection for doped layers fabricated using other methods, such as MBE, ion implantation and CVD deposition.

  11. Antireflective bilayer coatings based on Al2O3 film for UV region

    OpenAIRE

    Marszałek Konstanty; Winkowski Paweł; Marszałek Marta

    2015-01-01

    Bilayer antireflective coatings consisting of aluminium oxide Al2O3/MgF2 and Al2O3/SiO2 are presented in this paper. Oxide films were deposited by means of e-gun evaporation in vacuum of 5 × 10-3 Pa in the presence of oxygen, and magnesium fluoride was prepared by thermal evaporation on heated optical lenses made from quartz glass (Corning HPFS). Substrate temperature was maintained at 250 _C during the deposition. Thickness and deposition rate were controlled with a thickness measuring syste...

  12. Millimeter-Wave Broadband Anti-Reflection Coatings Using Laser Ablation of Sub-Wavelength Structures

    CERN Document Server

    Matsumura, Tomotake; Wen, Qi; Hanany, Shaul; Koch, Jürgen; Suttman, Oliver; Schütz, Viktor

    2016-01-01

    We report on the first use of laser ablation to make sub-millimeter, broad-band, anti-reflection coatings (ARC) based on sub-wavelength structures (SWS) on alumina and sapphire. We used a 515 nm laser to produce pyramid-shaped structures with pitch of about 320 \\mu m and total height of near 800 \\mu m. Transmission measurements between 70 and 140 GHz are in agreement with simulations using electromagnetic propagation software. The simulations indicate that SWS ARC with the fabricated shape should have a fractional bandwidth response of $\\Delta \

  13. Effect of Vacuum on the Laser-Induced Damage of Anti-Reflection Coatings

    Institute of Scientific and Technical Information of China (English)

    LING Xiu-Lan; ZHAO Yuan-An; LI Da-Wei; ZHOU Ming; SHAO Jian-Da; FAN Zheng-Xiu

    2009-01-01

    In the comparison of damage modifications, absorption measurement and energy dispersive x-ray analysis, the effect of vacuum on the laser-induced damage of anti-reflection coatings is analyzed. It is found that vacuum decreases the laser-induced damage threshold of the films. The low laser-induced damage threshold in vacuum environments as opposed to air environments is attributed to water absorption and the formation of the O/Si,O/Zr sub-stoichiometry in the course of laser irradiation.

  14. Optimization of hybrid antireflection structure integrating surface texturing and multi-layer interference coating

    Science.gov (United States)

    Kubota, Shigeru; Kanomata, Kensaku; Suzuki, Takahiko; Hirose, Fumihiko

    2014-10-01

    The antireflection structure (ARS) for solar cells is categorized to mainly two different techniques, i.e., the surface texturing and the single or multi-layer antireflection interference coating. In this study, we propose a novel hybrid ARS, which integrates moth eye texturing and multi-layer coat, for application to organic photovoltaics (OPVs). Using optical simulations based on the finite-difference time-domain (FDTD) method, we conduct nearly global optimization of the geometric parameters characterizing the hybrid ARS. The proposed optimization algorithm consists of two steps: in the first step, we optimize the period and height of moth eye array, in the absence of multi-layer coating. In the second step, we optimize the whole structure of hybrid ARS by using the solution obtained by the first step as the starting search point. The methods of the simple grid search and the Hooke and Jeeves pattern search are used for global and local searches, respectively. In addition, we study the effects of deviations in the geometric parameters of hybrid ARS from their optimized values. The design concept of hybrid ARS is highly beneficial for broadband light trapping in OPVs.

  15. Improved power conversion efficiency for dye-sensitized solar cells using a subwavelength-structured antireflective coating

    Science.gov (United States)

    Chou, Chun-Chi; Tsao, Kuan-Yi; Wu, Chih-Chung; Yang, Hongta; Chen, Chih-Ming

    2015-02-01

    Large-scale, subwavelength-structured nanodome arrays were successfully fabricated using simple, scalable bottom-up colloidal (nanosphere) lithography on a glass substrate as an efficient antireflective photoanode for dye-sensitized solar cells (DSSCs). A self-assembled monolayer of close-packed colloidal crystals (silica) was used as a structural template to pattern the two-dimensional subwavelength-structured nanodome arrays, which function as an efficient antireflective coating due to the graded refractive index across the interface between the air and specific nanodome array structure. The light harvesting for a DSSC with a subwavelength-structured antireflective coating was enhanced due to the improved broadband antireflectivity. Adjusting the nanodome size yielded a short-circuit current density (JSC) of 15.88 mA/cm2 with a power conversion efficiency (PCE) of 8.82%, which were both better than the reference cell without a subwavelength-structured antireflective coating (JSC = 15.26 mA/cm2 and PCE = 8.45%).

  16. Layer-by-layer-assembled high-performance broadband antireflection coatings.

    Science.gov (United States)

    Shimomura, Hiroomi; Gemici, Zekeriyya; Cohen, Robert E; Rubner, Michael F

    2010-03-01

    Nanoparticles are indispensable ingredients of solution-processed optical, dielectric, and catalytic thin films. Although solution-based methods are promising low-cost alternatives to vacuum methods, they can have significant limitations. Coating uniformity, thickness control, roughness control, mechanical durability, and incorporation of a diverse set of functional organic molecules into nanoparticle thin films are major challenges. We have used the electrostatic layer-by-layer assembly technique to make uniform, conformal multistack nanoparticle thin films for optical applications with precise thickness control over each stack. Two particularly sought-after optical applications are broadband antireflection and structural color. The effects of interstack and surface roughness on optical properties of these constructs (e.g., haze and spectral response) have been studied quantitatively using a combination of Fourier-transform methods and atomic force microscopy measurements. Deconvoluting root-mean-square roughness into its large-, intermediate-, and small-scale components enables enhanced optical simulations. A 4-stack broadband antireflection coating (cleaning test under 100 kPa normal stress.

  17. Layer-by-Layer-Assembled High-Performance Broadband Antireflection Coatings

    KAUST Repository

    Shimomura, Hiroomi

    2010-03-24

    Nanoparticles are indispensable ingredients of solution-processed optical, dielectric, and catalytic thin films. Although solution-based methods are promising low-cost alternatives to vacuum methods, they can have significant limitations. Coating uniformity, thickness control, roughness control, mechanical durability, and incorporation of a diverse set of functional organic molecules into nanoparticle thin films are major challenges. We have used the electrostatic layer-by-layer assembly technique to make uniform, conformal multistack nanoparticle thin films for optical applications with precise thickness control over each stack. Two particularly sought-after optical applications are broadband antireflection and structural color. The effects of interstack and surface roughness on optical properties of these constructs (e.g., haze and spectral response) have been studied quantitatively using a combination of Fourier-transform methods and atomic force microscopy measurements. Deconvoluting root-mean-square roughness into its large-, intermediate-, and small-scale components enables enhanced optical simulations. A 4-stack broadband antireflection coating (<0.5% average reflectance in the visible range, and 0.2% haze) composed of alternating high-index (n ≈ 1.96) and low-index (n ≈ 1.28) stacks has been made on glass substrate. Films calcinated at 550 °C endure a one-hour-long cloth cleaning test under 100 kPa normal stress. © 2010 American Chemical Society.

  18. Multifunctional antireflection coatings based on novel hollow silica-silica nanocomposites.

    Science.gov (United States)

    Zhang, Xianpeng; Lan, Pinjun; Lu, Yuehui; Li, Jia; Xu, Hua; Zhang, Jing; Lee, YoungPak; Rhee, Joo Yull; Choy, Kwang-Leong; Song, Weijie

    2014-02-12

    Antireflection (AR) coatings that exhibit multifunctional characteristics, including high transparency, robust resistance to moisture, high hardness, and antifogging properties, were developed based on hollow silica-silica nanocomposites. These novel nanocomposite coatings with a closed-pore structure, consisting of hollow silica nanospheres (HSNs) infiltrated with an acid-catalyzed silica sol (ACSS), were fabricated using a low-cost sol-gel dip-coating method. The refractive index of the nanocomposite coatings was tailored by controlling the amount of ACSS infiltrated into the HSNs during synthesis. Photovoltaic transmittance (TPV) values of 96.86-97.34% were obtained over a broad range of wavelengths, from 300 to 1200 nm; these values were close to the theoretical limit for a lossy single-layered AR coating (97.72%). The nanocomposite coatings displayed a stable TPV, with degradation values of less than 4% and 0.1% after highly accelerated temperature and humidity stress tests, and abrasion tests, respectively. In addition, the nanocomposite coatings had a hardness of approximately 1.6 GPa, while the porous silica coatings with an open-pore structure showed more severe degradation and had a lower hardness. The void fraction and surface roughness of the nanocomposite coatings could be controlled, which gave rise to near-superhydrophilic and antifogging characteristics. The promising results obtained in this study suggest that the nanocomposite coatings have the potential to be of benefit for the design, fabrication, and development of multifunctional AR coatings with both omnidirectional broadband transmission and long-term durability that are required for demanding outdoor applications in energy harvesting and optical instrumentation in extreme climates or humid conditions.

  19. Enhanced laser induced damage threshold of dielectric antireflection coatings by the introduction of one interfacial layer

    Institute of Scientific and Technical Information of China (English)

    Congjuan Wang; Zhaoxia Han; Yunxia Jin; Jianda Shao; Zhengxiu Fan

    2008-01-01

    @@ A new method for increasing laser induced damage threshold (LIDT) of dielectric antireflection (AR) coating is proposed. Compared with AR film stack of H2.5L (H:HfO2, L:SiO2) on BK7 substrate, SiO2 interfacial layer with four quarter wavelength optical thickness (QWOT) is deposited on the substrate before the preparation of H2.5L film. It is found that the introduction of SiO2 interfacial layer with a certain thickness is effective and flexible to increase the LIDT of dielectric AR coatings. The measured LIDT is enhanced by about 50%, while remaining the low reflectivity with less than 0.09% at the center wavelength of 1064 nm. Detailed mechanisms of the LIDT enhancement are discussed.

  20. ITO films for antireflective and antistatic tube coatings prepared by d.c. magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Loebl, H.P. [Philips Res. Labs., Aachen (Germany); Huppertz, M. [Philips Res. Labs., Aachen (Germany); Mergel, D. [University GH Essen, Fachbereich 7, Physik, D-45117, Essen (Germany)

    1996-07-01

    A reactive d.c. magnetron sputtering process with relatively high oxygen flow suitable for antireflective and antistatic (ARAS) coatings on display tubes is described. The sputtering conditions and their influence on optical, structural and electrical properties of indium tin oxide (ITO) films are discussed and compared with other ITO sputtering processes from a metallic target. Emphasis is placed on the relation between microstructure, defect structure and conductivity, and on the determination of the optimal process conditions for obtaining fine-grained films for optical applications that can withstand the 460 C heat treatment during tube assembly. As an example, a simple three-layer broadband ARAS coating is investigated, consisting of a transparent conductive ITO layer, a TiO{sub 2} layer and a SiO{sub 2} layer on top. (orig.)

  1. Self-assembled dual-sided hemispherical nano-dimple-structured broadband antireflection coatings

    Science.gov (United States)

    Lin, Cheng-Yen; Lin, Kun-Yi; Tsai, Hui-Ping; He, Yi-Xuan; Yang, Hongta

    2016-11-01

    A non-lithography-based approach is developed in this study for assembling monolayer close-packed hemispherical nano-dimple arrays on both sides of a PET film by a scalable Langmuir-Blodgett technology. The resulting gratings greatly suppress specular reflection and therefore enhance specular transmission for a broad range of visible wavelengths, resulting from a gradual change in the effective refractive index at air/PET interface. The experimental results reveal that the antireflection properties of the as-fabricated coatings are affected by the size of the nano-dimples. Moreover, both optical performances of single-sided and dual-sided nano-dimple-structured coatings have been investigated in this study.

  2. Effect of sol aging time on the anti-reflective properties of silica coatings templated with phosphoric acid

    Science.gov (United States)

    Wen, Wen; Li, Haibin; Chen, Xiaojing; Chang, Chengkang

    Silica anti-reflective coatings have been prepared by a sol-gel dip-coating process using the sol containing phosphoric acid as a pore-forming template. The effect of the aging time of the sol on the anti-reflective properties has been investigated. The surface topography of the silica AR coatings has been characterized. With increasing sol aging time, more over-sized pores larger than 100 nm are formed in the silica coatings. These could act as scattering centers, scattering visible light and thereby lowering transmittance. The optimal aging time was identified as 1 day, and the corresponding silica coatings showed a maximum transmittance of 99.2%, representing an 8% increase compared to the bare glass substrate.

  3. Deep Reactive Ion Etched Anti-Reflection Coatings for Sub-millimeter Silicon Optics

    CERN Document Server

    Gallardo, Patricio A; Cothard, Nicholas; Bruno, Sarah Marie M; Cortes-Medellin, German; Marchetti, Galen; Miller, Kevin H; Mockler, Brenna; Niemack, Michael D; Stacey, Gordon; Wollack, Edward J

    2016-01-01

    Refractive optical elements are widely used in millimeter and sub-millimeter astronomical telescopes. High resistivity silicon is an excellent material for dielectric lenses given its low loss-tangent, high thermal conductivity and high index of refraction. The high index of refraction of silicon causes a large Fresnel reflectance at the vacuum-silicon interface (up to 30%), which can be reduced with an anti-reflection (AR) coating. In this work we report techniques for efficiently AR coating silicon at sub-millimeter wavelengths using Deep Reactive Ion Etching (DRIE) and bonding the coated silicon to another silicon optic. Silicon wafers of 100 mm diameter (1 mm thick) were coated and bonded using the Silicon Direct Bonding technique at high temperature (1100 C). No glue is used in this process. Optical tests using a Fourier Transform Spectrometer (FTS) show sub-percent reflections for a single-layer DRIE AR coating designed for use at 320 microns on a single wafer. Cryogenic (10 K) measurements of a bonded ...

  4. Large-aperture wide-bandwidth antireflection-coated silicon lenses for millimeter wavelengths

    CERN Document Server

    Datta, R; Niemack, M D; McMahon, J J; Britton, J; Wollack, E J; Beall, J; Devlin, M J; Fowler, J; Gallardo, P; Hubmayr, J; Irwin, K; Newburgh, L; Nibarger, J P; Page, L; Quijada, M A; Schmitt, B L; Staggs, S T; Thornton, R; Zhang, L

    2013-01-01

    The increasing scale of cryogenic detector arrays for sub-millimeter and millimeter wavelength astrophysics has led to the need for large aperture, high index of refraction, low loss, cryogenic refracting optics. Silicon with n = 3.4, low loss, and relatively high thermal conductivity is a nearly optimal material for these purposes, but requires an antireflection (AR) coating with broad bandwidth, low loss, low reflectance, and a matched coefficient of thermal expansion. We present an AR coating for curved silicon optics comprised of subwavelength features cut into the lens surface with a custom three axis silicon dicing saw. These features constitute a metamaterial that behaves as a simple dielectric coating. We have fabricated and coated silicon lenses as large as 33.4 cm in diameter with coatings optimized for use between 125-165 GHz. Our design reduces average reflections to a few tenths of a percent for angles of incidence up to 30 degrees with low cross-polarization. We describe the design, tolerance, m...

  5. Multilayer antireflection coatings for the visible and near-infrared regions.

    Science.gov (United States)

    Shanbhogue, H G; Nagendra, C L; Annapurna, M N; Kumar, S A; Thutupalli, G K

    1997-09-01

    With a high-refractive-index mixed-oxide dielectric material of ZrTiO(4) and ZrO(2) [Substance H2 (Sub2) from E. Merck, Darmstadt, Germany], in combination with magnesium flouride (MgF(2)), design optimization and experimental production of low-loss antireflection (AR) coatings are carried out. Design-optimization studies that make use of these materials as constituents of a seven-layer coating system demonstrate that when the useful bandwidth of an AR coating is extended to cover a wider spectral range, the designs are in general found to have increased integrated reflection loss, higher ripple, and increased spectral instability. The experimental studies on Sub2 material show that the films have excellent optical performance over a wider process window, the advantage of which is demonstrated in the production of different AR coatings on a variety of glasses with refractive indices that range from 1.45 to 1.784 and different mechanical, thermal, and chemical properties. The manufacturing process of AR coatings shows a consistency better than 99% with respect to optical properties and durability.

  6. The Broadband Anti-reflection Coated Extended Hemispherical Silicon Lenses for Polarbear-2 Experiment

    Science.gov (United States)

    Siritanasak, P.; Aleman, C.; Arnold, K.; Cukierman, A.; Hazumi, M.; Kazemzadeh, K.; Keating, B.; Matsumura, T.; Lee, A. T.; Lee, C.; Quealy, E.; Rosen, D.; Stebor, N.; Suzuki, A.

    2016-08-01

    Polarbear-2 (PB-2) is a next-generation receiver that is part of the Simons Array cosmic microwave background (CMB) polarization experiment which is located in the Atacama desert in Northern Chile. The primary scientific goals of the Simons Array are a deep search for the CMB B-mode signature of gravitational waves from inflation and the characterization of large-scale structure using its effect on CMB polarization. The PB-2 receiver will deploy with 1897 dual-polarization sinuous antenna-coupled pixels, each with a directly contacting extended hemispherical silicon lens. Every pixel has dual polarization sensitivity in two spectral bands centered at 95 and 150 GHz, for a total of 7588 transition edge sensor bolometers operating at 270 mK. To achieve the PB-2 detector requirements, we developed a broadband anti-reflection (AR) coating for the extended hemispherical lenses that uses two molds to apply two layers of epoxy, Stycast 1090 and Stycast 2850FT. Our measurements of the absorption loss from the AR coating on a flat surface at cryogenic temperatures show less than 1 % absorption, and the coating has survived multiple thermal cycles. We can control the diameter of the coating within 25 {\\upmu }m and translation errors are within 25 {\\upmu }m in all directions, which results in less than 1 % decrease in transmittance. We also find the performance of the AR-coated lens matches very well with simulations.

  7. Titanium dioxide antireflection coating for silicon solar cells by spray deposition

    Science.gov (United States)

    Kern, W.; Tracy, E.

    1980-01-01

    A high-speed production process is described for depositing a single-layer, quarter-wavelength thick antireflection coating of titanium dioxide on metal-patterned single-crystal silicon solar cells for terrestrial applications. Controlled atomization spraying of an organotitanium solution was selected as the most cost-effective method of film deposition using commercial automated equipment. The optimal composition consists of titanium isopropoxide as the titanium source, n-butyl acetate as the diluent solvent, sec-butanol as the leveling agent, and 2-ethyl-1-hexanol to render the material uniformly depositable. Application of the process to the coating of circular, large-diameter solar cells with either screen-printed silver metallization or with vacuum-evaporated Ti/Pd/Ag metallization showed increases of over 40% in the electrical conversion efficiency. Optical characteristics, corrosion resistance, and several other important properties of the spray-deposited film are reported. Experimental evidence indicates a wide tolerance in the coating thickness upon the overall efficiency of the cell. Considerations pertaining to the optimization of AR coatings in general are discussed, and a comprehensive critical survey of the literature is presented.

  8. Single-material multilayer ZnS as anti-reflective coating for solar cell applications

    Science.gov (United States)

    Salih, Ammar T.; Najim, Aus A.; Muhi, Malek A. H.; Gbashi, Kadhim R.

    2017-04-01

    Multilayer Zinc Sulfide (ZnS) is a promising low cost antireflective coating for solar cell applications, in this work; thin films with novel structure containing cubic and hexagonal phases were successfully deposited by thermal evaporation technique with three different layers. XRD analysis confirms the existence of both phases and high specific surface area. AFM analysis reveals that films with three layers have lower roughness and average grain size than other films. The optical measurements obtained by UV-vis, the calculated values of refractive index and reflectivity using some well known refractive index-band gap relations indicate that thin films with triple layer TL-ZnS have lower refractive index and reflectivity than other films, empirical equations were suggested and show the quantum confinement effects on band gap and reflectivity.

  9. Highly transparent triboelectric nanogenerator for harvesting water-related energy reinforced by antireflection coating

    Science.gov (United States)

    Liang, Qijie; Yan, Xiaoqin; Gu, Yousong; Zhang, Kui; Liang, Mengyuan; Lu, Shengnan; Zheng, Xin; Zhang, Yue

    2015-03-01

    Water-related energy is an inexhaustible and renewable energy resource in our environment, which has huge amount of energy and is not largely dictated by daytime and sunlight. The transparent characteristic plays a key role in practical applications for some devices designed for harvesting water-related energy. In this paper, a highly transparent triboelectric nanogenerator (T-TENG) was designed to harvest the electrostatic energy from flowing water. The instantaneous output power density of the T-TENG is 11.56 mW/m2. Moreover, with the PTFE film acting as an antireflection coating, the maximum transmittance of the fabricated T-TENG is 87.4%, which is larger than that of individual glass substrate. The T-TENG can be integrated with silicon-based solar cell, building glass and car glass, which demonstrates its potential applications for harvesting waste water energy in our living environment and on smart home system and smart car system.

  10. Optical breathing of nano-porous antireflective coatings through adsorption and desorption of water

    Science.gov (United States)

    Nielsen, Karsten H.; Kittel, Thomas; Wondraczek, Katrin; Wondraczek, Lothar

    2014-10-01

    We report on the direct consequences of reversible water adsorption on the optical performance of silica-based nanoporous antireflective (AR) coatings as they are applied on glass in photovoltaic and solar thermal energy conversion systems. In situ UV-VIS transmission spectroscopy and path length measurements through high-resolution interferometric microscopy were conducted on model films during exposure to different levels of humidity and temperature. We show that water adsorption in the pores of the film results in a notable increase of the effective refractive index of the coating. As a consequence, the AR effect is strongly reduced. The temperature regime in which the major part of the water can be driven-out rapidly lies in the range of 55°C and 135°C. Such thermal desorption was found to increase the overall transmission of a coated glass by ~ 1%-point. As the activation energy of isothermal desorption, we find a value of about 18 kJ/mol. Within the experimental range of our data, the sorption and desorption process is fully reversible, resulting in optical breathing of the film. Nanoporous AR films with closed pore structure or high hydrophobicity may be of advantage for maintaining AR performance under air exposure.

  11. Optical breathing of nano-porous antireflective coatings through adsorption and desorption of water.

    Science.gov (United States)

    Nielsen, Karsten H; Kittel, Thomas; Wondraczek, Katrin; Wondraczek, Lothar

    2014-10-13

    We report on the direct consequences of reversible water adsorption on the optical performance of silica-based nanoporous antireflective (AR) coatings as they are applied on glass in photovoltaic and solar thermal energy conversion systems. In situ UV-VIS transmission spectroscopy and path length measurements through high-resolution interferometric microscopy were conducted on model films during exposure to different levels of humidity and temperature. We show that water adsorption in the pores of the film results in a notable increase of the effective refractive index of the coating. As a consequence, the AR effect is strongly reduced. The temperature regime in which the major part of the water can be driven-out rapidly lies in the range of 55°C and 135°C. Such thermal desorption was found to increase the overall transmission of a coated glass by ~ 1%-point. As the activation energy of isothermal desorption, we find a value of about 18 kJ/mol. Within the experimental range of our data, the sorption and desorption process is fully reversible, resulting in optical breathing of the film. Nanoporous AR films with closed pore structure or high hydrophobicity may be of advantage for maintaining AR performance under air exposure.

  12. A moisture-resistant antireflective coating by sol-gel process for neodymium-doped phosphate laser glass

    Institute of Scientific and Technical Information of China (English)

    Ruijun Liu; Ruoyu Zhan; Yongxing Tang; Jianqiang Zhu

    2006-01-01

    @@ Using methyl triethoxysilicane as precursor, a moisture-resistant coating for neodymium-doped laser glass was developed by the sol-gel process. Colloidal silica was added in coating solution as modifier. The refractive index of this coating varied from 1.31 to 1.42. A porous antireflective (AR) silica coating with the index of 1.27 was coated on the moisture-resistant coating surface. The two-layer coating possessed transmission up to 99.1% at wavelength of 966 nm, surface root-mean-square (RMS) roughness of 1.245nm, and roughness of average (RA) of 0.961 nm. In the case of laser of 1053-nm laser wavelength and 1-ns pulse duration, the damage threshold of the two-layer coatings was more than 15 J/cm2.

  13. Broadband anti-reflective and water-repellent coatings on glass substrates for self-cleaning photovoltaic cells

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiaoyu [Functional Nanomaterials Laboratory and Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry (TIPC), Chinese Academy of Sciences, Zhongguancun Donglu 29, Haidianqu, Beijing 100190 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); He, Junhui, E-mail: jhhe@mail.ipc.ac.cn [Functional Nanomaterials Laboratory and Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry (TIPC), Chinese Academy of Sciences, Zhongguancun Donglu 29, Haidianqu, Beijing 100190 (China); Liu, Weiyi [Institute of Optoelectronics, Nankai University, Tianjin 300071 (China)

    2013-07-15

    Graphical abstract: High performance broadband antireflective and water-repellent coatings were fabricated on glass substrates, which can improve the short-circuit current of solar cells as much as 6.6% in comparison with glass substrates without the coatings. - Highlights: • Broadband anti-reflective and water-repellent coatings were fabricated. • Transmittance increased to 99.0%, significantly higher than that of commercial solar glasses. • The performance of standard solar cells with the AR coating was enhanced as much as 6.6%. - Abstract: High performance broadband antireflective (AR) and water-repellent coatings were fabricated on glass substrates by assembly of silica nanoparticles and polyelectrolytes via the layer-by-layer (LbL) assembly technique, followed by calcination and hydrophobic modification. A porous poly(diallyladimethylammonium chloride) (PDDA)/20 nm SiO{sub 2} nanoparticles (S-20) multilayer coating with AR property was prepared first. The maximum transmittance is as high as 99.0%, while that of the glass substrate is only 91.3%. After calcination and hydrophobic modification, the coating became water-repellent while maintaining the good AR property. Such water-repellent AR coatings can improve the short-circuit current of solar cells as much as 6.6% in comparison with glass substrates without the coatings. Scanning electron microscopy (SEM) was used to observe the morphology and thickness of coatings. Transmission spectra and reflection spectra were characterized by UV–vis spectrophotometer. The surface wettability was studied by a contact angle/interface system.

  14. Breath Figure-Assisted Fabrication of Nanostructured Coating on Silicon Surface and Evaluation of Its Antireflection Power

    Directory of Open Access Journals (Sweden)

    Francesco Galeotti

    2016-01-01

    Full Text Available We report our recent results on the fabrication of nanostructured polymer layers aimed at developing efficient antireflection coating on silicon. The proposed manufacturing approach is based on self-assembly and relies on breath figure formation. By simple and straightforward operations, we are able to produce different nanostructured coatings: densely packed nanodomes, randomly distributed nanopores, and multilayered close-packed nanopores. By optical reflectivity measurements on coated silicon wafers, we show that the latter type of nanostructure is able to reduce the reflectivity of standard silicon surface (≈40% at 450 nm to about 10%.

  15. Process development and impurities analysis for the bottom antireflective coating material

    Science.gov (United States)

    Ko, Fu-Hsiang; Chen, Hsuen-Li; Huang, Tiao-Yuan; Cheng, Hsu-Chun; Ko, Chu-Jung; Chu, Tieh-Chi

    2001-08-01

    The optical behavior of semiconductor bottom antireflective coating (BARC) material was investigated by both the measurement and simulation methods. The effects of spin- coating rate, interface reflection, BARC layer thickness and photoresist layer thickness were studied. Our results indicated that the 62.5 nm of BARC layer had strong effect on suppressing the light reflection of wavelength of 248 nm form the wafer surface, irrespective of the photoresist layer thickness. Based on the gravimetric method, a high throughput and one-step microwave digestion procedure was developed for the BARC materials. The digestion efficiency increased with the digestion duration and the temperature. By following the established one-step microwave digestion method and inductively coupled plasma mass spectrometry determination, the detection limits obtained for Cr, Ni, Cu, An and Pb were in 0.1 to 1.11 ppb levels. The spike recoveries of the metallic impurities were in the range 86- 102% for the BARC materials. The analytical results of the BARC samples were found to be in reasonably good agreement with our previous method, and the analytical throughput can achieve up to 20 samples per hour for the analysis of 5 elements.

  16. Application of CBD-Zinc Sulfide Film as an Antireflection Coating on Very Large Area Multicrystalline Silicon Solar Cell

    Directory of Open Access Journals (Sweden)

    U. Gangopadhyay

    2007-01-01

    Full Text Available The low-cost chemical bath deposition (CBD technique is used to prepare CBD-ZnS films as antireflective (AR coating for multicrystalline silicon solar cells. The uniformity of CBD-ZnS film on large area of textured multicrystalline silicon surface is the major challenge of CBD technique. In the present work, attempts have been made for the first time to improve the rate of deposition and uniformity of deposited film by controlling film stoichiometry and refractive index and also to minimize reflection loss by proper optimization of molar percentage of different chemical constituents and deposition conditions. Reasonable values of film deposition rate (12.13 Å′/min., good film uniformity (standard deviation <1, and refractive index (2.35 along with a low percentage of average reflection (6-7% on a textured mc-Si surface are achieved with proper optimization of ZnS bath. 12.24% efficiency on large area (125 mm × 125 mm multicrystalline silicon solar cells with CBD-ZnS antireflection coating has been successfully fabricated. The viability of low-cost CBD-ZnS antireflection coating on large area multicrystalline silicon solar cell in the industrial production level is emphasized.

  17. Optical Properties of Spin-Coated TiO2 Antireflection Films on Textured Single-Crystalline Silicon Substrates

    Directory of Open Access Journals (Sweden)

    Ryosuke Watanabe

    2015-01-01

    Full Text Available Antireflection coating (ARC prepared by a wet process is beneficial for low cost fabrication of photovoltaic cells. In this study, we investigated optical properties and morphologies of spin-coated TiO2 ARCs on alkaline textured single-crystalline silicon wafers. Reflectance spectra of the spin-coated ARCs on alkaline textured silicon wafers exhibit no interferences and low reflectance values in the entire visible range. We modeled the structures of the spin-coated films for ray tracing numerical calculation and compared numerically calculated reflectance spectra with the experimental results. This is the first report to clarify the novel optical properties experimentally and theoretically. Optical properties of the spin-coated ARCs without interference are due to the fractional nonuniformity of the thickness of the spin-coated ARCs that cancels out the interference of the incident light.

  18. Non-Vacuum Processed Polymer Composite Antireflection Coating Films for Silicon Solar Cells

    Directory of Open Access Journals (Sweden)

    Abdullah Uzum

    2016-08-01

    Full Text Available A non-vacuum processing method for preparing polymer-based ZrO2/TiO2 multilayer structure antireflection coating (ARC films for crystalline silicon solar cells by spin coating is introduced. Initially, ZrO2, TiO2 and surface deactivated-TiO2 (SD-TiO2 based films were examined separately and the effect of photocatalytic properties of TiO2 film on the reflectivity on silicon surface was investigated. Degradation of the reflectance performance with increasing reflectivity of up to 2% in the ultraviolet region was confirmed. No significant change of the reflectance was observed when utilizing SD-TiO2 and ZrO2 films. Average reflectance (between 300 nm–1100 nm of the silicon surface coated with optimized polymer-based ZrO2 single or ZrO2/SD-TiO2 multilayer composite films was decreased down to 6.5% and 5.5%, respectively. Improvement of photocurrent density (Jsc and conversion efficiency (η of fabricated silicon solar cells owing to the ZrO2/SD-TiO2 multilayer ARC could be confirmed. The photovoltaic properties of Jsc, the open-circuit photo voltage (VOC, the fill factor (FF, and the η were 31.42 mA cm−2, 575 mV, 71.5% and 12.91%. Efficiency of the solar cells was improved by the ZrO2-polymer/SD-TiO2 polymer ARC composite layer by a factor of 0.8% with an increase of Jsc (2.07 mA cm−2 compared to those of fabricated without the ARC.

  19. Efficient Colorful Perovskite Solar Cells Using a Top Polymer Electrode Simultaneously as Spectrally Selective Antireflection Coating.

    Science.gov (United States)

    Jiang, Youyu; Luo, Bangwu; Jiang, Fangyuan; Jiang, Fuben; Fuentes-Hernandez, Canek; Liu, Tiefeng; Mao, Lin; Xiong, Sixing; Li, Zaifang; Wang, Tao; Kippelen, Bernard; Zhou, Yinhua

    2016-12-14

    Organometal halide perovskites have shown excellent optoelectronic properties and have been used to demonstrate a variety of semiconductor devices. Colorful solar cells are desirable for photovoltaic integration in buildings and other aesthetically appealing applications. However, the realization of colorful perovskite solar cells is challenging because of their broad and large absorption coefficient that commonly leads to cells with dark-brown colors. Herein, for the first time, we report a simple and efficient strategy to achieve colorful perovskite solar cells by using the transparent conducting polymer (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate), PEDOT:PSS) as a top electrode and simultaneously as an spectrally selective antireflection coating. Vivid colors across the visible spectrum are attained by engineering optical interference effects among the transparent PEDOT:PSS polymer electrode, the hole-transporting layer and the perovskite layer. The colored perovskite solar cells display power conversion efficiency values from 12.8 to 15.1% (from red to blue) when illuminated from the FTO glass side and from 11.6 to 13.8% (from red to blue) when illuminated from the PEDOT:PSS side. The new approach provides an advanced solution for fabricating colorful perovskite solar cells with easy processing and high efficiency.

  20. Localized dielectric breakdown and antireflection coating in metal-oxide-semiconductor photoelectrodes

    Science.gov (United States)

    Ji, Li; Hsu, Hsien-Yi; Li, Xiaohan; Huang, Kai; Zhang, Ye; Lee, Jack C.; Bard, Allen J.; Yu, Edward T.

    2017-01-01

    Silicon-based photoelectrodes for solar fuel production have attracted great interest over the past decade, with the major challenge being silicon's vulnerability to corrosion. A metal-insulator-semiconductor architecture, in which an insulator film serves as a protection layer, can prevent corrosion but must also allow low-resistance carrier transport, generally leading to a trade-off between stability and efficiency. In this work, we propose and demonstrate a general method to decouple the two roles of the insulator by employing localized dielectric breakdown. This approach allows the insulator to be thick, which enhances stability, while enabling low-resistance carrier transport as required for efficiency. This method can be applied to various oxides, such as SiO2 and Al2O3. In addition, it is suitable for silicon, III-V compounds, and other optical absorbers for both photocathodes and photoanodes. Finally, the thick metal-oxide layer can serve as a thin-film antireflection coating, which increases light absorption efficiency.

  1. Low-temperature grown indium oxide nanowire-based antireflection coatings for multi-crystalline silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yu-Cian; Chen, Chih-Yao; Chen, I Chen [Institute of Materials Science and Engineering, National Central University, Taoyuan (China); Kuo, Cheng-Wen; Kuan, Ta-Ming; Yu, Cheng-Yeh [TSEC Corporation, Hsinchu (China)

    2016-08-15

    Light harvesting by indium oxide nanowires (InO NWs) as an antireflection layer on multi-crystalline silicon (mc-Si) solar cells has been investigated. The low-temperature growth of InO NWs was performed in electron cyclotron resonance (ECR) plasma with an O{sub 2}-Ar system using indium nanocrystals as seed particles via the self-catalyzed growth mechanism. The size-dependence of antireflection properties of InO NWs was studied. A considerable enhancement in short-circuit current (from 35.39 to 38.33 mA cm{sup -2}) without deterioration of other performance parameters is observed for mc-Si solar cells coated with InO NWs. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Antireflective bilayer coatings based on Al2O3 film for UV region

    Directory of Open Access Journals (Sweden)

    Marszałek Konstanty

    2015-03-01

    Full Text Available Bilayer antireflective coatings consisting of aluminium oxide Al2O3/MgF2 and Al2O3/SiO2 are presented in this paper. Oxide films were deposited by means of e-gun evaporation in vacuum of 5 × 10-3 Pa in the presence of oxygen, and magnesium fluoride was prepared by thermal evaporation on heated optical lenses made from quartz glass (Corning HPFS. Substrate temperature was maintained at 250 _C during the deposition. Thickness and deposition rate were controlled with a thickness measuring system Inficon XTC/2. The experimental results of the optical measurements carried out during and after the deposition process have been presented. Physical thickness measurements were made during the deposition process and resulted in 44 nm/52 nm for Al2O3/MgF2 and 44 nm/50 nm for Al2O3/SiO2 system. Optimization was carried out for ultraviolet region with minimum of reflectance at 300 nm. The influence of post deposition annealing on the crystal structure was determined by X-ray measurements. In the range from ultraviolet to the beginning of visible region, the reflectance of both systems decreased and reached minimum at 290 nm. The value of reflectance at this point, for the coating Al2O3/MgF2 was equal to R290nm = 0.6 % and for Al2O3/SiO2R290nm = 1.1 %. Despite the difference between these values both are sufficient for applications in the UV optical systems for medicine and UV laser technology.

  3. Design and fabrication of anti-reflection coating on Gallium Phosphide, Zinc Selenide and Zinc Sulfide substrates for visible and infrared application

    Directory of Open Access Journals (Sweden)

    Mokrý P.

    2013-05-01

    Full Text Available Results of design and fabrication of a dual-band anti-reflection coating on a gallium phosphide (GaP, zinc selenide (ZnSe and zinc sulfide (ZnS substrates are presented. A multilayer stack structure of antireflection coatings made of zinc sulfide and yttrium fluoride (YF3 was theoretically designed for optical bands between 0.8 and 0.9 μm and between 9.5 and 10.5 μm. This stack was designed as efficient for these materials (GaP, ZnS, ZnSe together. Multilayer stack structure was deposited using thermal evaporation method. Theoretically predicted transmittance spectra were compared with transmitted spectra measured on coated substrates. Efficiency of anti-reflection coating is estimated and discrepancies are analyzed and discussed.

  4. [Study on the preparation and properties of novel silica microporous antireflective coating by sol-gel process].

    Science.gov (United States)

    Shang, Meng-Ying; Cao, Lin-Hong; Liu, Miao; Luo, Xuan; Ren, Hong-Bo; Ye, Xin; Tang, Yong-Jian; Jiang, Xiao-Dong

    2013-04-01

    Silica sol was prepared by acid catalyzed sol-gel process using tetraethylorthosilicate (TEOS) as precursor and dimethyldietoxysilane (DDS) as pore-forming agent. A novel kind of monolayer microporous silica anti-reflective (AR) coating was obtained on K9 glass substrate by dip-coating technique and then heat treated at 500 degrees C. The effects of different DDS/TEOS molar ratios on refractive index, transmittance and hardness were investigated. A positive correlation was found between the transmittance and the DDS/TEOS molar ratio due to the increasing porosity. The maximum transmittance can reach 99.7% with the molar ratio of DDS/TEOS rising to 1 : 1. Meanwhile, the refractive index was found quite close to the ideal value 1.22. Nevertheless, higher molar ratio will lead to a bad film-forming property. On the other hand, the hardness of the coatings decreased with the DDS increasing but still remained more than 2 h when the transmittance reached highest. Besides, these coatings exhibit a well abrasion-resistance and excellent adhesivity. The maximum transmittance was only dropped by 0.071% and 0.112% after abrasion for 500 and 1 000 times respectively. Accelerated corrosion tests indicated that the transmittance of traditional coatings rapidly fell down to the substrate level (-92%) after immersion for 5 min, while the transmittance of our novel coating almost linearly decreased and was kept 93.2% after 56 min. In other words, the environment-resistance of our novel silica AR coating is ten times higher than that of traditional ones. The promotions of the coating performances benefit from its micropore structure (-0. 4 nm) with which water molecule can be effectively prevented. With its high transmittance, good mechanical properties and high environment-resistance, this kind of novel coating has a potential application in the field of solar glass modification to improve its anti-reflective properties.

  5. The design of broad band anti-reflection coatings for solar cell applications

    Science.gov (United States)

    Siva Rama Krishna, Angirekula; Sabat, Samrat Lagnajeet; Ghanashyam Krishna, Mamidipudi

    2017-01-01

    The design of broadband anti-reflection coatings (ARCs) for solar cell applications using multiobjective differential evolutionary (MODE) algorithms is reported. The effect of thickness and refractive index contrast within the layers of the ARC on the bandwidth of reflectance is investigated in detail. In the case of the hybrid plasmonic ARC structures the effect of size, shape and filling fraction of silver (Ag) nanoparticles on the reflectance is studied. Bandwidth is defined as the spectral region of wavelengths over which the reflectance is below 2%. Single, two and three layers ARCs (consisting of MgF2, Al2O3, Si3N4, TiO2 and ZnS or combinations of these materials) were simulated for performance evaluation on an a-Si photovoltaic cell. It is observed that the three layer ARC consisting of MgF2/Si3N4/TiO2(ZnTe) of 81/42/36 nm thicknesses, respectively, exhibited a weighted reflectance of 1.9% with a bandwidth of 450 nm over the wavelength range of 300-900 nm. The ARC bandwidth could be further improved by embedding randomly distributed Ag nanoparticles of size between 100 and 120 nm on a two layer ARC consisting of Al2O3/TiO2 with thickness of 42 nm and 56 nm respectively. This plasmon-dielectric hybrid ARC design exhibited a weighted reflectance of 0.6% with a bandwidth of 560 nm over the wavelength range of 300-900 nm.

  6. Laser damage initiation and growth of antireflection coated S-FAP crystal surfaces prepared by pitch lap and magnetorheological finishing

    Energy Technology Data Exchange (ETDEWEB)

    Stolz, C J; Menapace, J A; Schaffers, K I; Bibeau, C; Thomas, M D; Griffin, A J

    2005-10-31

    Antireflection (AR) coatings typically damage at the interface between the substrate and coating. Therefore the substrate finishing technology can have an impact on the laser resistance of the coating. For this study, AR coatings were deposited on Yb:S-FAP [Yb{sup 3+}:Sr{sub 5}(PO{sub 4}){sub 3}F] crystals that received a final polish by both conventional pitch lap finishing as well as magnetorheological finishing (MRF). SEM images of the damage morphology reveals laser damage originates at scratches and at substrate coating interfacial absorbing defects. Previous damage stability tests on multilayer mirror coatings and bare surfaces revealed damage growth can occur at fluences below the initiation fluence. The results from this study suggest the opposite trend for AR coatings. Investigation of unstable HR and uncoated surface damage morphologies reveals significant radial cracking that is not apparent with AR damage due to AR delamination from the coated surface with few apparent cracks at the damage boundary. Damage stability tests show that coated Yb:S-FAP crystals can operate at 1057 nm at fluences around 20 J/cm{sup 2} at 10 ns; almost twice the initiation damage threshold.

  7. Single mode operation and extended scanning of anti-reflection coated visible laser diodes in a Littrow cavity

    Science.gov (United States)

    Lonsdale, D. J.; Andrews, D. A.; King, T. A.

    2004-05-01

    A method to increase the mode-hop-free tuning range is presented that is suitable for application with visible and short wavelength laser diodes, and relaxes the requirement on high tolerance mechanical components. Depending on the diode and cavity, the theory predicts an improvement of up to eight times the FSR of the extended cavity. In our system, an anti-reflection coated AlGaInP laser diode showed a mode-hop-free scan of 8 GHz, which is characteristic for the wavelength used in the device. Greater scanning ranges are predicted for shorter wavelength sources.

  8. Wide band antireflective coatings Al2O3 / HfO2 / MgF2 for UV region

    Science.gov (United States)

    Winkowski, P.; Marszałek, Konstanty W.

    2013-07-01

    Deposition technology of the three layers antireflective coatings consists of hafnium compound are presented in this paper. Oxide films were deposited by means of e-gun evaporation in vacuum of 5x10-5 mbar in presence of oxygen and fluoride films by thermal evaporation. Substrate temperature was 250°C. Coatings were deposited onto optical lenses made from quartz glass (Corning HPFS). Thickness and deposition rate were controlled by thickness measuring system Inficon XTC/2. Simulations leading to optimization of thickness and experimental results of optical measurements carried during and after deposition process were presented. Physical thickness measurements were made during deposition process and were equal to 43 nm/74 nm/51 nm for Al2O3 / HfO2 / MgF2 respectively. Optimization was carried out for ultraviolet region from 230nm to the beginning of visible region 400 nm. In this region the average reflectance of the antireflective coating was less than 0.5% in the whole range of application.

  9. A simplified method for generating periodic nanostructures by interference lithography without the use of an anti-reflection coating

    Science.gov (United States)

    Kapon, Omree; Muallem, Merav; Palatnik, Alex; Aviv, Hagit; Tischler, Yaakov. R.

    2015-11-01

    Interference lithography has proven to be a useful technique for generating periodic sub-diffraction limited nanostructures. Interference lithography can be implemented by exposing a photoresist polymer to laser light using a two-beam arrangement or more simply a one beam configuration based on a Lloyd's Mirror Interferometer. For typical photoresist layers, an anti-reflection coating must be deposited on the substrate to prevent adverse reflections from cancelling the holographic pattern of the interfering beams. For silicon substrates, such coatings are typically multilayered and complex in composition. By thinning the photoresist layer to a thickness well below the quarter wavelength of the exposing beam, we demonstrate that interference gratings can be generated without an anti-reflection coating on the substrate. We used ammonium dichromate doped polyvinyl alcohol as the positive photoresist because it provides excellent pinhole free layers down to thicknesses of 40 nm, and can be cross-linked by a low-cost single mode 457 nm laser, and can be etched in water. Gratings with a period of 320 nm and depth of 4 nm were realized, as well as a variety of morphologies depending on the photoresist thickness. This simplified interference lithography technique promises to be useful for generating periodic nanostructures with high fidelity and minimal substrate treatments.

  10. A simplified method for generating periodic nanostructures by interference lithography without the use of an anti-reflection coating

    Energy Technology Data Exchange (ETDEWEB)

    Kapon, Omree; Muallem, Merav; Palatnik, Alex; Aviv, Hagit; Tischler, Yaakov R. [Department of Chemistry, Bar-Ilan University, Ramat-Gan 5920002 (Israel); Bar-Ilan University Institute for Nanotechnology and Advanced Materials, Ramat-Gan 5920002 (Israel)

    2015-11-16

    Interference lithography has proven to be a useful technique for generating periodic sub-diffraction limited nanostructures. Interference lithography can be implemented by exposing a photoresist polymer to laser light using a two-beam arrangement or more simply a one beam configuration based on a Lloyd's Mirror Interferometer. For typical photoresist layers, an anti-reflection coating must be deposited on the substrate to prevent adverse reflections from cancelling the holographic pattern of the interfering beams. For silicon substrates, such coatings are typically multilayered and complex in composition. By thinning the photoresist layer to a thickness well below the quarter wavelength of the exposing beam, we demonstrate that interference gratings can be generated without an anti-reflection coating on the substrate. We used ammonium dichromate doped polyvinyl alcohol as the positive photoresist because it provides excellent pinhole free layers down to thicknesses of 40 nm, and can be cross-linked by a low-cost single mode 457 nm laser, and can be etched in water. Gratings with a period of 320 nm and depth of 4 nm were realized, as well as a variety of morphologies depending on the photoresist thickness. This simplified interference lithography technique promises to be useful for generating periodic nanostructures with high fidelity and minimal substrate treatments.

  11. Injection moulding antireflective nanostructures

    DEFF Research Database (Denmark)

    Christiansen, Alexander Bruun; Clausen, Jeppe Sandvik; Mortensen, N. Asger;

    We present a method for injection moulding antireflective nanostructures on large areas, for high volume production. Nanostructured black silicon masters were fabricated by mask-less reactive ion etching, and electroplated with nickel. The nickel shim was antistiction coated and used...... index of the nanostructured surfaces was estimated from atomic force micrographs and the theoretical reflectance was calculated using the transfer matrix method and effective medium theory. The measured reflectance shows good agreement with the theory of graded index antireflective nanostructures...

  12. Graphene oxide as a p-dopant and an anti-reflection coating layer, in graphene/silicon solar cells

    Science.gov (United States)

    Yavuz, S.; Kuru, C.; Choi, D.; Kargar, A.; Jin, S.; Bandaru, P. R.

    2016-03-01

    It is shown that coating graphene-silicon (Gr/Si) Schottky junction based solar cells with graphene oxide (GO) improves the power conversion efficiency (PCE) of the cells, while demonstrating unprecedented device stability. The PCE has been shown to be increased to 10.6% (at incident radiation of 100 mW cm-2) for the Gr/Si solar cell with an optimal GO coating thickness compared to 3.6% for a bare/uncoated Gr/Si solar cell. The p-doping of graphene by the GO, which also serves as an antireflection coating (ARC) has been shown to be a main contributing factor to the enhanced PCE. A simple spin coating process has been used to apply GO with thickness commensurate with an anti-refection coating (ARC) and indicates the suitability of the developed methodology for large-scale solar cell assembly.It is shown that coating graphene-silicon (Gr/Si) Schottky junction based solar cells with graphene oxide (GO) improves the power conversion efficiency (PCE) of the cells, while demonstrating unprecedented device stability. The PCE has been shown to be increased to 10.6% (at incident radiation of 100 mW cm-2) for the Gr/Si solar cell with an optimal GO coating thickness compared to 3.6% for a bare/uncoated Gr/Si solar cell. The p-doping of graphene by the GO, which also serves as an antireflection coating (ARC) has been shown to be a main contributing factor to the enhanced PCE. A simple spin coating process has been used to apply GO with thickness commensurate with an anti-refection coating (ARC) and indicates the suitability of the developed methodology for large-scale solar cell assembly. Electronic supplementary information (ESI) available: (i) Experimental methods, (ii) optical images of devices with and without graphene oxide (GO), (iii) comparison of the power conversion efficiency (PCE) due to the GO coating and nitric acid doping, (iv) specular and diffuse reflectance measurements, (v) stability data of pristine graphene/silicon (Gr/Si) solar cells. See DOI: 10.1039/c5

  13. Investigation on the Ability of Antireflection Coating to Withstand the Destructive Effects of Laser Radiation in IR Range (10.6 Micrometers),

    Science.gov (United States)

    2014-09-26

    at the mid-IR, KCl and NaCl are commonly selected as substrates. But for the CO2 laser , a Ge substrate coated with a *i ZnS AR coating, is still widely...intensity of the laser increases, these microscopic damages interact with the laser , thus absorbing more energy from the light field, and the...FOREIGN TECHNOLOGY DIVISION INVESTIGATION ON THE ABILITY OF ANTIREFLECTION COATING TO WITHSTAND THE DESTRUCTIVE EFFECTS OF LASER RADIATION IN IR RANGE

  14. Superior Antireflection Coating for a Silicon Cell with a Micronanohybrid Structure

    Directory of Open Access Journals (Sweden)

    Hsi-Chien Liu

    2014-01-01

    Full Text Available The object of this paper is to develop a high antireflection silicon solar cell. A novel two-stage metal-assisted etching (MAE method is proposed for the fabrication of an antireflective layer of a micronanohybrid structure array. The processing time for the etching on an N-type high-resistance (NH silicon wafer can be controlled to around 5 min. The resulting micronanohybrid structure array can achieve an average reflectivity of 1.21% for a light spectrum of 200–1000 nm. A P-N junction on the fabricated micronanohybrid structure array is formed using a low-cost liquid diffusion source. A high antireflection silicon solar cell with an average efficiency of 13.1% can be achieved. Compared with a conventional pyramid structure solar cell, the shorted circuit current of the proposed solar cell is increased by 73%. The major advantage of the two-stage MAE process is that a high antireflective silicon substrate can be fabricated cost-effectively in a relatively short time. The proposed method is feasible for the mass production of low-cost solar cells.

  15. Two-layer anti-reflection coating with mullite and polyimide foam for large-diameter cryogenic infrared filters

    CERN Document Server

    Inoue, Yuki; Hasegawa, Masaya; Hazumi, Masashi; Hori, Yasuto; Suzuki, Aritoki; Tomaru, Takayuki; Matsumura, Tomotake; Sakata, Toshifumi; Minamoto, Tomoyuki; Hirai, Tohru

    2016-01-01

    We have developed a novel two-layer anti-reflection (AR) coating method for large-diameter infrared (IR) filters made of alumina, for the use at cryogenic temperatures in millimeter wave measurements. Thermally- sprayed mullite and polyimide foam (Skybond Foam) are used as the AR material. An advantage of the Skybond Foam is that the index of refraction is chosen between 1.1 and 1.7 by changing the filling factor. Combination with mullite is suitable for wide-band millimeter wave measurements with sufficient IR cutoff capability. We present the material properties, fabrication of a large-diameter IR filter made of alumina with this AR coating method, and characterizations at cryogenic temperatures. This technology can be applied to a low-temperature receiver system with a large-diameter focal plane for next-generation cosmic microwave background (CMB) polarization measurements, such as POLARBEAR-2 (PB-2).

  16. Functional photocatalytically active and scratch resistant antireflective coating based on TiO2 and SiO2

    Science.gov (United States)

    Mazur, M.; Wojcieszak, D.; Kaczmarek, D.; Domaradzki, J.; Song, S.; Gibson, D.; Placido, F.; Mazur, P.; Kalisz, M.; Poniedzialek, A.

    2016-09-01

    Antireflection (AR) multilayer coating, based on combination of five TiO2 and SiO2 thin films, was deposited by microwave assisted reactive magnetron sputtering process on microscope glass substrates. In this work X-ray diffraction, X-ray photoelectron spectroscopy, atomic force microscopy and wettability measurements were used to characterize the structural and surface properties of the deposited coating. These studies revealed that prepared coating was amorphous with low surface roughness. Photocatalytic properties were determined based on phenol decomposition reaction. Measurements of optical properties showed that transmittance in the visible wavelength range was increased after the deposition of AR coating as-compared to bare glass substrate. The mechanical properties were determined on the basis of nano-indentation and scratch resistance tests. Performed research has shown that deposition of an additional thin 10 nm thick TiO2 thin film top layer, the prepared AR coating was photocatalytically active, hydrophobic, scratch resistant and had increased hardness as-compared to bare glass substrate. These results indicate that prepared AR multilayer could be used also as a self-cleaning and protective coating.

  17. Research Progress on Antireflection Coating for Silicon Solar Cells%硅太阳能电池减反射膜的研究进展

    Institute of Scientific and Technical Information of China (English)

    王彦青; 王秀峰; 江红涛; 门永

    2012-01-01

    综述了国内外对硅太阳能电池减反射膜的研究进展,包括减反射膜的种类、膜层结构、减反射原理以及减反射膜的制备方法,重点介绍了硅太阳能电池减反射膜的主要制备方法,并对比了各种制备方法的优缺点,指出新型制备技术和新膜系的选取是目前硅太阳能电池减反射膜的研究重点.最后讨论了硅太阳能电池减反射膜存在的问题,并提出进一步发展的方向.%The research progress of antireflection at home and abroad is summarized, including in antireflection materials, the structure of film, principle of antireflective and preparing technology, and the focus is placed on the preparing technology, advantages and disadvantages of each preparation methods is contrasted, new preparing technology and new film system are pointed out. At last, the existing problem of antireflection coating for silicon solar cells are discussed and the development trends of antireflection coating for silicon solar cells are forecasted.

  18. Effect of Different TiO2-SiO2 Multilayer Coatings Applied by Sol-Gel Method on Antireflective Property

    Science.gov (United States)

    lari, Najme; Ahangarani, Shahrokh; Shanaghi, Ali

    2015-07-01

    Multilayer thin films prepared using the sol-gel process have been used in many antireflection applications. In this paper, antireflective nanoscale multilayer TiO2-SiO2 coatings were formed on both sides of the glass substrates by combining sol-gel method and dip coating techniques. The coatings were carried out using tetraethyl orthosilicate as precursor for SiO2 and tetrabutyl orthotitanate as precursor for TiO2. The coatings prepared in this work were characterized using scanning electron microscope, Fourier-transformed infrared spectrophotometer and UV-Visible spectrophotometer. The SiO2 top layer coatings showed excellent antireflection in the wavelength range of 400-800 nm where the transmittance of glass substrate is significantly lower. By increasing the number of double TiO2-SiO2 layers, the transmission of the coated glasses increased due to applied multilayer coating properties. Six-layer sol-gel TiO2-SiO2 coatings showed the highest visible transmittance about 99.25% at the band of 550-650 nm.

  19. THE INFLUENCE OF PLASMONIC AND DIELECTRIC INCLUSIONS ON ANTIREFLECTIVE PROPERTIES OF HOMOGENEOUS COATINGS FOR SILICON PHOTOVOLTAIC STRUCTURES

    Directory of Open Access Journals (Sweden)

    K. V. Baryshnikova

    2015-09-01

    Full Text Available Subject of Study. Theoretical analysis of the efficiency for the antireflective coatings based on plasmonic silver (Ag and dielectric silicon (Si nanoparticles is presented. We observe the increase of light absorption in the active layer, which is related to the optical resonant properties of considered nanoparticles. Characteristic property of the studied composite layer is its ability to combine the functions of electric contacts and anti-reflective coating. Method. Numerical calculations were performed in CST Microwave Studio with FDFD method (Finite Difference in Frequency Domain. The optical parameters of materials were extracted from the experimentally measured data available in literature. Geometrical parameters of composite layer – size and location of particles – were varied. Comparison of light absorption efficiency for different coatings on top of the active layer is presented: the homogeneous Indium Tin Oxide (ITO layer, ITO layer with the spherical nanoparticle inclusions on the ITO surface, ITO layer with spherical nanoparticle bulk inclusions. Periodical lattices of particles with sizes of range between 15 and 80 nm were considered. Nanoparticles of this size have dominant dipole response. Main Results. Numerical calculations have shown that nanoparticle inclusions cause significant deformation of the absorption spectra with appearing of resonant pecularities in the wavelength range equal to 300-800 nm. It originates from the nanoparticle resonant features, which are similar to the resonant features of isolated nanoparticles. Absorption in the active layer decreases sharply at the resonant wavelength. Resonant response of nanoparticles placed on the ITO surface differs significally from the isolated ones: the resonant frequency and Q-factor decrease. It was shown that absorption in the active layer decreases by 25 % when the size of Ag and Si particles increases. Ag nanoparticles, placed in ITO layer on top of the active layer

  20. Studies and testing of antireflective (AR) coatings for soda-lime glass. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Pastirik, E.M.; Sparks, T.G.; Coleman, M.G.

    1978-05-01

    Experimental results on this feasibility study to establish processes for producing antireflection films on glass coverings for encapsulated solar cells are very encouraging. Efforts have been concentrated in three areas: acid etching of glass, plasma etching of glass, and acid development of sodium silicate films on glass. The best transmission to date has been achieved through the acid etching technique, while the most durable films have been produced from development of sodium silicate films. Control of the acid etching technique is presently inadequate for production implementation, and large scale application methods for sodium silicate films need further definition. While films having excellent antireflective properties have been fabricated by plasma etching techniques, all have been water soluble, disqualifying the films from a weatherability standpoint.

  1. Influence of Vacuum Organic Contaminations on Laser-Induced Damage of 1064 nm Anti-Reflective Coatings

    Institute of Scientific and Technical Information of China (English)

    CUI Yun; LIU Shi-Jie; HE Hong-Bo; ZHAO Yuan-An; SHAO Jian-Da; FAN Zheng-Xiu

    2007-01-01

    We investigate the influence of vacuum organic contaminations on laser-induced damage threshold (LIDT) of optical coatings. Anti-reflective (AR) coatings at 1064nm made by Ta2O5/SiO2 are deposited by the ion beam sputtering method. The LIDTs of AR coatings are measured in vacuum and in atmosphere, respectively. It is exhibited that contaminations in vacuum are easily to be absorbed onto optical surface because of lower pressure,and they become origins of damage, resulting in the decrease of LIDT from 24.5 J/cm2 in air to 15.7J/cm2 in vacuum. The LIDT of coatings in vacuum has is slightly changed compared with the value in atmosphere after the organic contaminations are wiped off. These results indicate that organic contaminations are the main reason of the LIDT decrease in vacuum. Additionally, damage morphologies have distinct changes from vacuum to atmosphere because of the differences between the residual stress and thermal decomposability of filmy materials.

  2. Nearly zero reflectance of nano-pyramids and dual-antireflection coating structure for monocrystalline silicon solar cells.

    Science.gov (United States)

    Chang, Hyo Sik; Jung, Hyun-Chul

    2011-04-01

    The effect of two-step surface treatment on monocrystalline silicon solar cells was investigated. We changed the nanostructure on pyramidal surfaces by wet nano-texturing so that less light is reflected. The two-step nano-texturing process reduces the average reflectance to about 4% in the 300-1100 nm wavelength region. The use of an antireflection coating resulted in an effective reflectance of 1%. We found that the reflectance obtained by wet nano-texturing was lower than that obtained by conventional alkaline texturing. Thus, we can expect a further increase in the efficiency of silicon solar cells with two-step nano-texturing by a wet chemical process.

  3. Self-organized TiO2 nanorod arrays on glass substrate for self-cleaning antireflection coatings.

    Science.gov (United States)

    Mu, Qinghui; Li, Yaogang; Wang, Hongzhi; Zhang, Qinghong

    2012-01-01

    Herein we report the direct fabrication of TiO(2) subwavelength structures with 1-dimensional TiO(2) nanorods on glass substrate through solvothermal process to form self-cleaning antireflection coatings. TiO(2) precursor solutions with different solvent constituents create TiO(2) nanorods with much different morphologies grown on glass substrates. Apiculate TiO(2) nanorods with vertical orientation are grown on the glass substrate which is solvothermally treated in the precursor solution containing ethylene glycol. This glass substrate exhibit the highest transmittance of 70-85% in the range of 520-800 nm and negligible absorption in visible light region (400-800 nm). Furthermore, the TiO(2) nanorod arrays show high hydrophobicity and photocatalytic degradation ability which offer the glass substrate self-cleaning properties for both hydrophilic and oily contaminants.

  4. An abrasion-resistant and broadband antireflective silica coating by block copolymer assisted sol-gel method.

    Science.gov (United States)

    Zou, Liping; Li, Xiaoguang; Zhang, Qinghua; Shen, Jun

    2014-09-02

    A double-layer broadband antireflective (AR) coating was prepared on glass substrate via sol-gel process using two kinds of acid-catalyzed TEOS-derived silica sols. The relative dense layer with a porosity of ∼10% was obtained from an as-prepared sol, while the porous layer with a porosity of ∼55% was from a modified one with block copolymer (BCP) Pluronic F127 as template which results in abundant ordered mesopores. The two layers give rise to a reasonable refractive index gradient from air to the substrate and thus high transmittance in a wide wavelength range, and both of them have the same tough skeleton despite different porosity, for which each single-layer and the double-layer coatings all behaved well in the mechanical property tests. The high transmittance and the strong ability of resisting abrasion make this coating promising for applications in some harsh conditions. In addition, the preparation is simple, low-cost, time-saving, and flexible for realizing the optical property.

  5. Injection moulding antireflective nanostructures

    DEFF Research Database (Denmark)

    Christiansen, Alexander Bruun; Clausen, Jeppe Sandvik; Mortensen, N. Asger

    2014-01-01

    We present a method for injection moulding antireflective nanostructures on large areas, for high volume production. Nanostructured black silicon masters were fabricated by mask-less reactive ion etching, and electroplated with nickel. The nickel shim was antistiction coated and used in an inject...

  6. Anti-reflection coatings on large area glass sheets. Final report, Motorola report No. 2366/4, DRD No. SE-5

    Energy Technology Data Exchange (ETDEWEB)

    Pastirik, E.

    1980-09-01

    Antireflective coatings which may be suitable for use on the covers of photovoltaic solar modules can be easily produced by a dipping process. The coatings are applied to glass by drawing sheets of glass vertically out of dilute aqueous sodium silicate solutions at a constant speed, allowing the adherent liquid film to dry, then exposing the dried film to concentrated sulfuric acid, followed by a water rinse and dry. The process produces coatings of good optical performance (96.7% peak transmission at 0.540 ..mu..M wavelength) combined with excellent stain and soil resistance, and good resistance to abrasion. The process is reproduceable and easily controlled.

  7. TiO2/Ni composite as antireflection coating for solar cell application

    Science.gov (United States)

    Haider, Adawiya J.; Najim, Aus A.; Muhi, Malik A. H.

    2016-07-01

    Titanium dioxide (TiO2) considered as one of the best material already used as a window in solar cells due to its antireflection capability. In this work, pure and Ni-doped (1, 3 and 5 wt%) TiO2 thin films were deposited using pulsed laser deposition (PLD) method. The optical measurements obtained by UV-vis indicate that the highest optical band gap was found with (5%) doping level (Eg=3.82 eV), corresponding to a lower reflectance and higher transmittance. Empirical equations between energy band gap and concentration level, reflectance with energy band gap, refractive index and concentration have been determined; a perfect fit with the experimental data was obtained.

  8. Finite-difference time-domain simulations of fabricated black silicon nanostructures: Optimal geometries for an antireflective coating

    Energy Technology Data Exchange (ETDEWEB)

    Williamson, Adam [X-FAB Semiconductor Foundries AG, Erfurt (Germany); Technische Universitaet Ilmenau (Germany); Voerckel, Andreas [X-FAB Semiconductor Foundries AG, Erfurt (Germany)

    2010-07-01

    Nano-structured silicon has received a growing and serious amount of interest in industrial technology and university research, particularly in regard to the possibility of such nanostructures in optics, with the primary interest here being black silicon as an anti-reflective coating (ARC) for photodiodes. Current literature now contains a wealth of morphological information to influence structure growth and shape in fluorine-based plasma etching in the presence of oxide-forming or fluorocarbon gas inhibitors. Using the computationally efficient grid-based differential time-domain numerical modeling of the finite-difference time-domain (FDTD) method, approximations to Maxwell's equations are solved to model the optical properties of crystalline black silicon. Multiple geometries, from pillars to more pyramid and needle-like structures, are considered and results are correlated to actual scanning electron microscope (SEM) pictures with corresponding reflection measurements taken in a Cary 5000 UV*VIS spectrophotometer with accompanying integrating (Ulbricht) sphere from 200 nm to 800 nm to evaluate both diffuse and specular reflection from the silicon surface. Optimal geometries are simulated and the consequences for photodiode applications are discussed.

  9. Optimal structure of light trapping in thin-film solar cells: dielectric nanoparticles or multilayer antireflection coatings?

    Science.gov (United States)

    Zhao, Yongxiang; Chen, Fei; Shen, Qiang; Zhang, Lianmeng

    2014-08-10

    Recent research has found an alternative way to enhance light trapping of thin-film solar cells by using dielectric nanoparticles deposited on the cell surface. To improve the performance of light trapping, a systematic study on the influence of dielectric nanoparticles on enhancement efficiency is performed in this paper. We prove that the optimal dielectric nanoparticles are substantially equivalent to the multilayer antireflection coatings (ARCs) with a "low-high-low" dielectric constant profile. Moreover, it is demonstrated that the use of a simple two-layer SiO2/SiC ARC can reach 34.15% enhancement, which has exceeded the ideal limit of 32% of nanoparticles structure including plasmonic Ag nanoparticles, dielectric SiC, and TiO2 nanoparticles. That means the optimal multilayer ARCs structure is obviously superior to the optimal dielectric nanoparticles structure, and the deposition of a simple two-layer SiO2/SiC structure on top of a thin-film silicon solar cell can significantly enhance photoelectron generation and hence, result in superior performance of thin-film solar cells.

  10. High-Quality Hollow Closed-Pore Silica Antireflection Coatings Based on Styrene-Acrylate Emulsion @ Organic-Inorganic Silica Precursor.

    Science.gov (United States)

    Guo, Zhaolong; Zhao, Haixin; Zhao, Wei; Wang, Tao; Kong, Depeng; Chen, Taojing; Zhang, Xiaoyan

    2016-05-11

    Making use of a facile and low-cost way for the preparation of a hierarchically organized novel hollow closed-pore silica antireflective coating (CHAR) with tailored optical properties and a mechanical reliability is of great interest in the field of solar photovoltaic technology. The process mainly contains two aspects: (1) a styrene-acrylate emulsion @ organic-inorganic silica precursor (SA@OISP) core/shell hierarchical nanostructure, consisting of a sacrificial styrene-acrylate (SA) primary template, was fabricated using a sol-gel method; (2) the self-assembly of the nanostructures leads to SA@OISP nanospheres forming the high-quality hollow closed-pore silica antireflection coating (CHAR) by a dip-coating process and a subsequent calcination treatment. The resulting SA@OISP nanospheres have a mean diameter of 65.2 nm and contained a SA soft core with a mean diameter of approximately 54.8 nm and an organic-inorganic silica precursor (OISP) shell with a thickness of approximately 6-10 nm. Furthermore, the prepared CHAR film exhibited a high transmittance and good ruggedness. An average transmittance (TAV) of 97.64% was obtained, and the value is close to the ideal single-layered antireflection coating (98.09%) over a broad range of wavelengths (from 380 to 1100 nm). The CHAR film showed a stable TAV, with attenuation values of less than 0.8% and 0.43% after the abrasion test and the damp heat test, respectively. The conversion efficiency of the CHAR coating cover solar modules tends to be increased by 3.75%. The promising results obtained in this study suggest that the CHAR film was considered as an essential component of the solar module and were expected to provide additional solar energy harvest under extreme outdoor climates.

  11. Nano-Enabled Low-Cost High-Performance UV Anti-Reflection Coatings Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Agiltron together with Prof. Michael Rubner's group at MIT is developing a new family of nanoporous, low refractive index coatings for next generation NASA UV...

  12. Broad Bandwidth Meta-Material Antireflection Coatings for Measurement of the Cosmic Microwave Background Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The effort's objective is to realize broadband low-reflectance coatings. The two key technical challenges are the design of the precision engineered materials...

  13. Thermography and k-means clustering methods for anti-reflective coating film inspection: scratch and bubble defects

    Science.gov (United States)

    Zhou, Xunfei; Wang, Hongjin; Hsieh, Sheng-Jen (Tony)

    2016-05-01

    Anti-reflective coating is widely used on telescopes, eyeglasses and screens to effectively enhance the transmission of light. However, the presence of defects such as bubbles or scratches lowers the usability and functionality of optical film. Optical cameras are often used for coating inspection, but their accuracy relies heavily on the illumination source, camera viewing angles and defect location. This paper describes an active thermography approach that can potentially overcome this issue. Eighteen scratch and bubble defects were located on AR film with dimensions ranging from 0.03mm to 4.4 mm. An infrared camera was used to capture thermal images of those defects over 65 seconds of heating. After the thermal images were acquired, time-domain analysis and space-domain analysis were conducted and k-means clustering methodology was used to highlight the defective area. Results suggest active thermography can be used to detect scratch defects with widths of 0.03mm to 4.40 mm and bubble defects with diameters ranging from 0.08 to 4 mm. For defects with dimensions larger than 0.4 mm, our algorithm can estimate the dimension with less than 15% bias. However, for defects with dimensions less than 0.4mm, the algorithm estimation error ranged from 68% to 900% due to camera resolution limitations. It should be noted that our algorithm can still distinguish a scratch defect with a width of less than one pixel. This study also suggests active thermography can detect scratch and bubble defects regardless of the location of the illumination source.

  14. Self-cleaning antireflective coatings assembled from peculiar mesoporous silica nanoparticles.

    Science.gov (United States)

    Li, Xiaoyu; Du, Xin; He, Junhui

    2010-08-17

    Novel mesoporous silica nanoparticles of peculiar shapes were synthesized, from which hierarchically porous silica coatings were fabricated on glass substrates via layer-by-layer (LbL) assembly, followed by calcination. These porous silica coatings were highly transparent and superhydrophilic. The maximum transmittance reached as high as 94%, whereas that of the glass substrate is 91%. The time for a droplet to spread lower than 5 degrees decreased to as short as 0.25 s. After the coating surface was treated with a low surface energy material, the surface became superhydrophobic (water contract angle >150 degrees) with a very low sliding angle of cleaning property. We used scanning (SEM) and transmission (TEM) electron microscopy to observe the morphology and structure of nanoparticles and surfaces. Transmission spectra and their change with time were characterized by UV-vis spectrophotometer. We studied the surface wettability by a contact angle/interface system. The influence of mesopores on the transmittance and wetting properties of coatings was discussed on the basis of experimental observations.

  15. An Evaluation of Atmospheric-pressure Plasma for the Cost-Effective Deposition of Antireflection Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Rob Sailer; Guruvenket Srinivasan; Kyle W. Johnson; Douglas L. Schulz

    2010-04-01

    Atmospheric-pressure plasma deposition (APPD) has previously been used to deposit various functional materials including polymeric surface modification layers, transparent conducting oxides, and photo catalytic materials. For many plasma polymerized coatings, reaction occurs via free radical mechanism where the high energy electrons from the plasma activate the olefinic carbon-carbon double bonds - a typical functional group in such precursors. The precursors for such systems are typically inexpensive and readily available and have been used in vacuum PECVD previously. The objectives are to investigate: (1) the effect of plasma power, gas composition and substrate temperature on the Si-based film properties using triethylsilane(TES) as the precursor; and (2) the chemical, mechanical, and optical properties of several experimental matrices based on Design of Experiment (DOE) principals. A simple APPD route has been utilized to deposit Si based films from an inexpensive precursor - Triethylsilane (TES). Preliminary results indicates formation of Si-C & Si-O and Si-O, Si-C & Si-N bonds with oxygen and nitrogen plasmas respectively. N{sub 2}-O{sub 2} plasma showed mixed trend; however oxygen remains a significant portion of all films, despite attempts to minimize exposure to atmosphere. SiN, SiC, and SiO ratios can be modified by the reaction conditions resulting in differing film properties. SE studies revealed that films with SiN bond possess refractive index higher than coatings with Si-O/Si-C bonds. Variable angle reflectance studies showed that SiOCN coatings offer AR properties; however thickness and refractive index optimization of these coatings remains necessary for application as potential AR coatings.

  16. Sol gel TiO2 antireflection coatings for silicon solar cells

    Directory of Open Access Journals (Sweden)

    L.A. Dobrzański

    2012-05-01

    Full Text Available Purpose: The aim of this paper was to investigate changes in surface morphology and optical reflection of thin films of titanium dioxide. Thin films were prepared using sol gel spin coating method.Design/methodology/approach: The microanalysis have been investigated by the Energy-dispersive X-ray spectroscopy EDS. The changes in surface topography was observed by the atomic force microscope AFM and scanning electron microscope SEM. The results of roughness have been prepared in the software XEI Park Systems and optical reflection by the spectrometer UV/VIS.Findings: Results and their analysis allow to conclude that the titanium isopropoxide concentration in solution and spin speed, which is an important factor in spin coating technology has a significant influence on surface morphology and optical reflection of thin films titanium dioxide.Practical implications: Known sol gel titanium dioxide optical parameters and the possibility of obtaining a uniform thin films show that it can be good material for photovoltaic application.Originality/value: The paper presents some researches of titanium dioxide thin films deposited by sol gel spin coating method on monocrystalline silicon.

  17. Nanocrystalline ZnO film deposited by ultrasonic spray on textured silicon substrate as an anti-reflection coating layer

    Energy Technology Data Exchange (ETDEWEB)

    Sali, S., E-mail: samira_sali@yahoo.fr [Silicon Technology Development Unit (UDTS), 02 Bd, Frantz FANON, B.P. 140, Algiers (Algeria); Houari Boumediene University (USTHB), Faculty of Physics, Algiers (Algeria); Boumaour, M. [Silicon Technology Development Unit (UDTS), 02 Bd, Frantz FANON, B.P. 140, Algiers (Algeria); Kechouane, M. [Houari Boumediene University (USTHB), Faculty of Physics, Algiers (Algeria); Kermadi, S.; Aitamar, F. [Silicon Technology Development Unit (UDTS), 02 Bd, Frantz FANON, B.P. 140, Algiers (Algeria)

    2012-07-01

    A ZnO thin film was successfully synthesized on glass, flat surface and textured silicon substrates by chemical spray deposition. The textured silicon substrate was carried out using two solutions (NaOH/IPA and Na{sub 2}CO{sub 3}). Textured with Na{sub 2}CO{sub 3} solution, the sample surface exhibits uniform pyramids with an average height of 5 {mu}m. The properties and morphology of ZnO films were investigated. X-ray diffraction (XRD) spectra revealed a preferred orientation of the ZnO nanocrystalline film along the c-axis where the low value of the tensile strain 0.26% was obtained. SEM images show that all films display a granular, polycrystalline morphology. The morphology of the ZnO layers depends dramatically on the substrate used and follows the contours of the pyramids on the substrate surface. The average reflectance of the textured surface was found to be around 13% and it decreases dramatically to 2.57% after deposition of a ZnO antireflection coating. FT-IR peaks arising from the bonding between Zn-O are clearly represented using a silicon textured surface. A very intense photoluminescence (PL) emission peak is observed for ZnO/textured Si, revealing the good quality of the layer. The PL peak at 380.5 nm (UV emission) and the high-intensity PL peak at 427.5 nm are observed and a high luminescence occurs when using a textured Si substrate.

  18. Preparation and stress evolution of sol–gel SiO2 antireflective coatings for small-size anisotropic lithium triborate crystals

    Directory of Open Access Journals (Sweden)

    Bingtao Tian

    2016-04-01

    Full Text Available Lithium triborate (LiB3O5, LBO crystal is now one of the most useful nonlinear optical materials for frequency conversion of high power lasers. The use of the crystal, however, has been hampered by the unavailability of antireflective (AR coatings with high laser damage resistance. In this work, a “point contact” dip-coating method is developed to prepare sol–gel SiO2 AR coatings on small-size LBO crystals. Using this approach, we obtain a homogenous coating surface on an 8 mm×8 mm×3 mm LBO crystal. The stress measurements show that the stresses in sol–gel SiO2 coatings vary with the time of natural drying, which is beyond our expectation. The anisotropic Young’s modulus of the LBO crystal and the different evolution tendency of the stress in the different SiO2 coating layers are found to be responsible for the crack of the double-layer AR coatings on anisotropic LBO crystal. Meanwhile, the resulting coatings on LBO crystal achieve a LIDT of over 15 J/cm2 (532 nm, 3ns and the coated LBO is expected to have a transmittance of over 99% at 800 nm.

  19. Boosting the performance of the ASTRI SST-2M prototype: reflective and anti-reflective coatings

    CERN Document Server

    Perri, Luca

    2013-01-01

    ASTRI is a Flagship Project of the Italian Ministry of Education, University and Research, led by the Italian National Institute of Astrophysics, INAF. One of the main aims of the ASTRI Project is the design, construction and verification on-field of a dual mirror (2M) end-to-end prototype for the Small Size Telescope (SST) envisaged to become part of the Cherenkov Telescope Array. The ASTRI SST-2M prototype adopts the Schwarzschild-Couder design, and a camera based on SiPM (Silicon Photo Multiplier); it will be assembled at the INAF astronomical site of Serra La Nave on mount Etna (Catania, Italy) within mid 2014, and will start scientific validation phase soon after. The peculiarities of the optical design and of the SiPM bandpass pushed towards specifically optimized choices in terms of reflective coatings for both the primary and the secondary mirror. In particular, multi-layer dielectric coatings, capable of filtering out the large Night Sky Background contamination at wavelengths $\\lambda \\gtrsim 700$ n...

  20. Composite films prepared by plasma ion-assisted deposition (IAD) for design and fabrication of antireflection coatings in visible and near-infrared spectral regions

    Science.gov (United States)

    Tsai, Rung-Ywan; Ho, Fang C.

    1994-11-01

    Ion-assisted deposition (IAD) processes configured with a well-controlled plasma source at the center base of a vacuum chamber, which accommodates two independent e-gun sources, is used to deposition TiO2MgF2 and TiO2-SiO2 composite films of selected component ratios. Films prepared by this technology are found durable, uniform, and nonabsorbing in visible and near-IR regions. Single- and multilayer antireflection coatings with refractive index from 1.38 to 2.36 at (lambda) equals 550 nm are presented. Methods of enhancement in optical performance of these coatings are studied. The advantages of AR coatings formed by TiO2-MgF2 composite films over those similar systems consisting of TiO2-SiO2 composite films in both visible and near-IR regions are also presented.

  1. Functional photocatalytically active and scratch resistant antireflective coating based on TiO{sub 2} and SiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Mazur, M., E-mail: michal.mazur@pwr.edu.pl [Wroclaw University of Technology, Faculty of Microsystem Electronics and Photonics, Janiszewskiego 11/17, 50-372 Wroclaw (Poland); Wojcieszak, D.; Kaczmarek, D.; Domaradzki, J. [Wroclaw University of Technology, Faculty of Microsystem Electronics and Photonics, Janiszewskiego 11/17, 50-372 Wroclaw (Poland); Song, S.; Gibson, D.; Placido, F. [Institute of Thin Films, Sensors & Imaging, University of the West of Scotland, Scottish Universities Physics Alliance, High Street, Paisley PA1 2BE (United Kingdom); Mazur, P. [University of Wroclaw, Institute of Experimental Physics, Max Born 9, 50-204 Wroclaw (Poland); Kalisz, M. [Motor Transport Institute, Centre for Material Testing and Mechatronics, Jagiellonska 80, 03-301 Warsaw (Poland); Poniedzialek, A. [Wroclaw University of Technology, Faculty of Microsystem Electronics and Photonics, Janiszewskiego 11/17, 50-372 Wroclaw (Poland)

    2016-09-01

    Graphical abstract: - Highlights: • Designed multilayer was deposited by microwave assisted magnetron sputtering method. • AR coating in designed wavelength range had transmittance higher than 97%. • The AR multilayer was hydrophobic and photocatalytically active. • AR coating was scratch resistant. • Deposited multilayer had higher hardness than the glass substrate. - Abstract: Antireflection (AR) multilayer coating, based on combination of five TiO{sub 2} and SiO{sub 2} thin films, was deposited by microwave assisted reactive magnetron sputtering process on microscope glass substrates. In this work X-ray diffraction, X-ray photoelectron spectroscopy, atomic force microscopy and wettability measurements were used to characterize the structural and surface properties of the deposited coating. These studies revealed that prepared coating was amorphous with low surface roughness. Photocatalytic properties were determined based on phenol decomposition reaction. Measurements of optical properties showed that transmittance in the visible wavelength range was increased after the deposition of AR coating as-compared to bare glass substrate. The mechanical properties were determined on the basis of nano-indentation and scratch resistance tests. Performed research has shown that deposition of an additional thin 10 nm thick TiO{sub 2} thin film top layer, the prepared AR coating was photocatalytically active, hydrophobic, scratch resistant and had increased hardness as-compared to bare glass substrate. These results indicate that prepared AR multilayer could be used also as a self-cleaning and protective coating.

  2. Effect of diffuse roof cover with anti-reflection coating for roses; Effect van diffuus kasdek met Anti Reflectie coating bij Roos

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Victoria, N.; Kempkes, F.

    2012-10-15

    The rose Red Naomi was cultivated in two greenhouses at Wageningen UR Greenhouse Horticulture in Bleiswijk, Netherlands (August 2010 - September 2011). One greenhouse covered with normal float glass; the other with AR coated diffuse glass (70% haze). This Anti-Reflection coating on both glass sides compensated for the loss in light transmission caused by the diffusing structure in the glass. The diffuse AR glass lead to a 5.2% higher production (>6.1% fresh weight). Sunscreens were necessary in spring and summer to avoid high light levels on the flower buds, as they cause very high bud temperatures leading to quality problems (blue petal edges and burnt leaf tips). The diffuse greenhouse cover allowed a 100 W/m{sup 2} higher screening threshold than the reference glass. This caused a 2.7% higher daily light integral, able to explain part of the extra production obtained. Part of the extra production achieved can not be explained by the measured factors as no differences were found in the amount of light intercepted by the crop or in leaf photosynthesis under both cover types. The light under the diffuse AR cover was nevertheless much smoother, so the crop seemed to suffer less (lower bud temperatures and less burned leaf tips), and this should provide an explanation for the rest of the extra production. The cover properties did not influence disease development (powdery mildew). The obtained extra production makes the tempered, diffuse glass with Anti Reflection coating on both sides economically feasible [Dutch] Tussen augustus 2010 en september 2011 is bij Wageningen UR Glastuinbouw het effect van diffuus glas, met dubbelzijdige AR coating, op de productie en energiegebruik van roos 'Red Naomi' onderzocht. Onder het diffuse glas werden 5,2% meer bloemtakken geproduceerd, deze rozen waren ook iets langer en zwaarder (6,1% meer versgewicht). Dit verschil kan deels verklaard worden doordat er onder het diffuse glas pas bij hogere stralingsniveau

  3. Synthesis of raspberry-like SiO2-TiO2 nanoparticles toward antireflective and self-cleaning coatings.

    Science.gov (United States)

    Li, Xiaoyu; He, Junhui

    2013-06-12

    Silica-titania core-shell nanoparticles of 30, 40, 50, 55, 75, and 110 nm were prepared from tetraethyl orthosilicate (TEOS) and tetraisopropyl titanate (TIPT). After calcination, the amorphous titania shell transformed into anatase nanoparticles, and the silica-titania core-shell nanoparticles became raspberry-like nanoparticles. These nanoparticles were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and UV-vis spectroscopy. Hierarchically structured antireflective and self-cleaning particulate coatings were fabricated on glass substrates via layer-by-layer (LbL) assembly using silica-titania core-shell nanoparticles and silica nanoparticles as building blocks followed by calcination. The maximum transmittance of coated glass substrates reached as high as ca. 97%, while that of the glass substrates is only ca. 91%. The morphologies of the coatings were observed by SEM and atom force microscopy (AFM). Such hierarchically structured raspberry-like SiO2-TiO2 nanoparticle coatings had superhydrophilic and antifogging properties. The coatings also showed photocatalytic activity toward organic pollutants and thus a self-cleaning property.

  4. Formation of a macro-porous SiO2 layer as an anti-reflective coating on glass substrates.

    Science.gov (United States)

    Park, No-Kuk; Kim, Yong Sul; Kim, Min Jung; Lee, Tae Jin; Lee, Seung Hyun; Lee, Seung Hun

    2013-11-01

    A macro-porous silica layer, consisting of a silica layer with macro-sized pores, was formed as an antireflective material on glass substrates. The silica layer and macro-pores were formed by the oxidative thermal decomposition of tetra-ethylorthorsilicate (TEOS) used as the precursor and polystyrene (PS) spherical beads used as the polymer template for the macro-pores at high temperatures. The size of pores was determined by the size of PS beads in the antireflective agent solution. The size of the PS spherical beads can be controlled by changing the concentration of styrene monomer, and the porosity of the macro pore in the silica layer could be controlled by the TEOS/PS ratio. The optimal thermal treating temperature for the formation of a macro-porous silica layer was found to be 650 degrees C. The size of the spherical type macro pores formed in the silica layer on the glass substrate was 100-150 nm. UV-Vis spectrophotometry confirmed the improved antireflective properties of the glass substrate with the macro-porous silica layer.

  5. Investigation of mechanically hard, chemically inert antireflection coatings for photovoltaic solar modules. Final technical report, April 1, 1980-March 31, 1981

    Energy Technology Data Exchange (ETDEWEB)

    Moravec, T.J.

    1981-03-31

    The overall objective of this program is to determine the optical properties of i-Carbon (diamond-like) films and determine if these films can be developed into antireflecting (AR) coatings for silicon solar cells. The i-C films have been produced on glass, silicon, and KCl by radio frequency (RF) plasma decomposition of the alkane gases. Films were also produced on silicon solar cells by low-energy ion beam techniques. These coatings did not perform as well as those made from hydrocarbon gases. Significant progress has been made in understanding the deposition parameters that affect the optical properties of the films. The optical constants n and k have been determined over a large range of process parameters and source gas. The degree of hydrogen incorporation in these films has been studied by SIMS analysis. It was found that the lower optically absorbing films contain more hydrogen. This hydrogen does not, however, manifest itself in fundamental C-H absorption bands in the infrared. Very efficient single-layer quarter-wave i-C AR coatings have been produced on single-crystal and SOC Si solar cells. An increase in cell efficiency of 40% over uncoated cells has been achieved.

  6. 双波段激光防护红外减反膜的研制%Design and Fabrication of Double Wavelength Laser Protective Infrared Antireflection Coatings

    Institute of Scientific and Technical Information of China (English)

    石澎; 付秀华; 孙岩; 魏孜洵; 梅禹珊

    2011-01-01

    针对军用光电仪器对激光致盲武器的防护要求,选取Si和YbF3,ZnS和YbF3两种高低折射率组合形式研制了激光防护减反膜.在多光谱ZnS基底上,采用电子束及离子辅助沉积技术,制备了能够对532 nm和1064 nm激光进行有效防护,同时对3~5μm的波段具有高透射率的薄膜.对Si膜的电子束沉积工艺进行了研究;对YbF3在不同的材料组合中的沉积工艺进行了优化;解决了膜层与基底之间的粘附性问题.该薄膜集探测用减反器件和防护器件于一体,可以使星载、机载等光电仪器的结构得到简化;光谱分析和环境测试的结果表明,各项指标满足使用要求.%In order to protect the military opto-electronic instruments from laser blinding weapons, the high and low refractive index combinations of Si and YbF3, ZnS and YbF3 are selected to design and fabricate laser protective infrared antireflection coatings. On the substrate of multi-spectral ZnS, coatings with laser protective function to 532 nm and 1064 nm laser while with high transmittance in the 3~5 μm spectral band are fabricated, and electron beam and ion assisted deposition technique is used in this process. The deposition process of Si by electron beam is studied, and the deposition process of YbF3 in different materials combination is optimized. The adhesion problem between coatings and substrate is resolved. Devices of antireflection for detection and protection are both integrated into the coatings, and the structures of opto-electronic instruments for satellite and aeroplane can be simplified.Results of spectrum analysis and environmental test show that all the parameters meet the requirements.

  7. Plasmonic effect of Ag nanoparticles in a SiON antireflective coating: engineering rules and physical barrier

    Science.gov (United States)

    Lecler, S.; Bastide, S.; Tan, J.; Qu, M.; Slaoui, A.; Fix, T.

    2016-10-01

    Surface plasmon polaritons have been proposed in the architectures of several solar cells as a way to enhance light collection and thus to increase their efficiency. Here, Ag nanoparticles (NPs) are embedded in a SiON antireflective layer using an electroless technique. The plasmonic effects are modeled and observed experimentally for NPs 5 to 200 nm in size. The systematic comparison of scattering and extinction efficiencies computed as a function of the NPs and surrounding medium properties allows establishing engineering rules, validated by the experimental measurements. The fact that Ag NPs larger than 30 nm mainly contribute to light scattering and therefore to optical path enlargement (green-red light), whereas those smaller than 15 nm absorb light by light trapping (blue-green), is demonstrated and physically explained. A physical barrier making it impossible to shift the dominant resonance beyond 650 nm is pointed out.

  8. Design of a Three-Layer Antireflection Coating for High Efficiency Indium Phosphide Solar Cells Using a Chemical Oxide as First Layer

    Science.gov (United States)

    Moulot, Jacques; Faur, Mircea; Faur, Maria; Goradia, Chandra; Goradia, Manju; Bailey, Sheila

    1995-01-01

    It is well known that the behavior of III-V compound based solar cells is largely controlled by their surface, since the majority of light generated carriers (63% for GaAs and 79% for InP) are created within 0.2 microns of the illuminated surface of the cell. Consequently, the always observed high surface recombination velocity (SRV) on these cells is a serious limiting factor for their high efficiency performance, especially for those with the p-n junction made by either thermal diffusion or ion implantation. A good surface passivation layer, ideally, a grown oxide as opposed to a deposited one, will cause a significant reduction in the SRV without adding interface problems, thus improving the performance of III-V compound based solar cells. Another significant benefit to the overall performance of the solar cells can be achieved by a substantial reduction of their large surface optical reflection by the use of a well designed antireflection (AR) coating. In this paper, we demonstrate the effectiveness of using a chemically grown, thermally and chemically stable oxide, not only for surface passivation but also as an integral part of a 3- layer AR coating for thermally diffused p(+)n InP solar cells. A phosphorus-rich interfacial oxide, In(PO3)3, is grown at the surface of the p(+) emitter using an etchant based on HNO3, o-H3PO4 and H2O2. This oxide has the unique properties of passivating the surface as well as serving as a fairly efficient antireflective layer yielding a measured record high AM0, 25 C, open-circuit voltage of 890.3 mV on a thermally diffused InP(Cd,S) solar cell. Unlike conventional single layer AR coatings such as ZnS, Sb2O3, SiO or double layer AR coatings such as ZnS/MgF2 deposited by e-beam or resistive evaporation, this oxide preserves the stoichiometry of the InP surface. We show that it is possible to design a three-layer AR coating for a thermally diffused InP solar cell using the In(PO3)3 grown oxide as the first layer and Al2O3, MgF2 or

  9. A novel perfluorinated AR (antireflective) and protective coating for KDP (potassium dihydrogen phosphate) and other optical materials

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, I.M.; Campbell, J.H.

    1990-12-17

    A new commercially available perfluorinated organic polymer has been used to prepare a combined quarterwave AR and protective coating for KDP and other optical materials. Coatings are applied from solution at room temperature by spin or dip, they are fully dense and have a refractive index of 1.29. The laser damage threshold at 1064 nm and 355 nm is the highest that we have ever measured for an AR coating material. 5 refs., 8 figs., 3 tabs.

  10. Antireflective porous-silicon coatings for multicrystalline solar cells: the effects of chemical etching and rapid thermal processing

    Energy Technology Data Exchange (ETDEWEB)

    Martin-Palma, R.J.; Martinez-Duart, J.M. [Universidad Autonoma de Madrid (Spain). Dept. de Fisica Aplicada; Instituto de Ciencia des Materiales de Madrid (CSIC) (Spain); Vazquez, L. [Instituto de Ciencia des Materiales de Madrid (CSIC) (Spain); Schnell, M.; Schaefer, S. [Fraunhofer Institute for Solar Energy Systems, Freiburg (Germany)

    2001-08-01

    In this paper, the emitter of multicrystalline silicon solar cells has been chemically etched in order to form porous silicon (PS) layers, usually known as stain-etched PS, to be used at the same time as a selective emitter and as an effective antireflective layer. The optical behaviour of the solar cells in the 250-850 nm wavelength range (5-1.45 eV range) was determined before and after PS formation, resulting in a notable reduction of reflectance after PS formation and a corresponding increase in cell efficiency. The different morphologies of the silicon emitter and metallic contacts, before and after PS formation were analysed by scanning electron microscopy and atomic force microscopy. Furthermore, the electrical properties of both the emitter region and the contacts were investigated, as well as the most significant solar cell parameters before and after PS formation. Finally, the effect of rapid thermal processing in nitrogen and oxygen atmospheres on both the surface morphology and the optical behaviour of PS was studied. (Author)

  11. Fabrication and characterization of silicon wire solar cells having ZnO nanorod antireflection coating on Al-doped ZnO seed layer.

    Science.gov (United States)

    Baek, Seong-Ho; Noh, Bum-Young; Park, Il-Kyu; Kim, Jae Hyun

    2012-01-05

    In this study, we have fabricated and characterized the silicon [Si] wire solar cells with conformal ZnO nanorod antireflection coating [ARC] grown on a Al-doped ZnO [AZO] seed layer. Vertically aligned Si wire arrays were fabricated by electrochemical etching and, the p-n junction was prepared by spin-on dopant diffusion method. Hydrothermal growth of the ZnO nanorods was followed by AZO film deposition on high aspect ratio Si microwire arrays by atomic layer deposition [ALD]. The introduction of an ALD-deposited AZO film on Si wire arrays not only helps to create the ZnO nanorod arrays, but also has a strong impact on the reduction of surface recombination. The reflectance spectra show that ZnO nanorods were used as an efficient ARC to enhance light absorption by multiple scattering. Also, from the current-voltage results, we found that the combination of the AZO film and ZnO nanorods on Si wire solar cells leads to an increased power conversion efficiency by more than 27% compared to the cells without it.

  12. Optical properties of the Al2O3/SiO2 and Al2O3/HfO2/SiO2 antireflective coatings

    Science.gov (United States)

    Marszałek, Konstanty; Winkowski, Paweł; Jaglarz, Janusz

    2014-01-01

    Investigations of bilayer and trilayer Al2O3/SiO2 and Al2O3/HfO2/SiO2 antireflective coatings are presented in this paper. The oxide films were deposited on a heated quartz glass by e-gun evaporation in a vacuum of 5 × 10-3 [Pa] in the presence of oxygen. Depositions were performed at three different temperatures of the substrates: 100 °C, 200 °C and 300 °C. The coatings were deposited onto optical quartz glass (Corning HPFS). The thickness and deposition rate were controlled with Inficon XTC/2 thickness measuring system. Deposition rate was equal to 0.6 nm/s for Al2O3, 0.6 nm - 0.8 nm/s for HfO2 and 0.6 nm/s for SiO2. Simulations leading to optimization of the thin film thickness and the experimental results of optical measurements, which were carried out during and after the deposition process, have been presented. The optical thickness values, obtained from the measurements performed during the deposition process were as follows: 78 nm/78 nm for Al2O3/SiO2 and 78 nm/156 nm/78 nm for Al2O3/HfO2/SiO2. The results were then checked by ellipsometric technique. Reflectance of the films depended on the substrate temperature during the deposition process. Starting from 240 nm to the beginning of visible region, the average reflectance of the trilayer system was below 1 % and for the bilayer, minima of the reflectance were equal to 1.6 %, 1.15 % and 0.8 % for deposition temperatures of 100 °C, 200 °C and 300 °C, respectively.

  13. Ultra-thin atomic-layer deposited alumina incorporating silica sol makes ultra-durable antireflection coatings

    Science.gov (United States)

    Li, Jia; Lan, Pinjun; Xu, Hua; Zhang, Xianpeng; Yang, Ye; Tan, Ruiqin; Jylhä, Olli; Lu, Yuehui

    2012-11-01

    We propose a strategy to make soda-lime glass maintain both high transparency and long-term durability in stringent high temperature and humid environments. Experiments reveal that the double-layered coatings with 110-nm-thick SiO2 and ultra-thin 25-nm- or 50-nm-thick Al2O3 layers, prepared by sol-gel dip coating and atomic layer deposition (ALD), respectively, exhibit the improvement of 5.88-6.32% in Tave (the average transmittance from the wavelength of 400-700 nm), as compared with that of the bare glass. On the other hand, the highly accelerated temperature and humidity stress test (HAST) confirms that both samples can sustain the 180 h test without any proven transmittance degradation, while the normalized Tave of the bare glass drastically drops to 43.1% of the initial value after the 108 h HAST. It implies that the ultra-thin Al2O3 films prepared by ALD, followed by dip-coated low-index layers such as SiO2 or nanostructured layer, can achieve both higher average transmittance and better durability, which would be of significance for the applications of ALD and dip coating techniques in the fields of consumer electronics, architecture with glass facades, and photovoltaics.

  14. The optimization of triple layer anti-reflection coatings and its application on solar cells%三层减反射膜的模拟及其在太阳电池中的应用

    Institute of Scientific and Technical Information of China (English)

    宫臣; 张静全; 冯良桓; 武莉莉; 李卫; 黎兵; 曾广根; 王文武

    2013-01-01

    The anti-reflection coatings with the structure of Al2O3/H4/MgF2 triple layer were prepared with electron beam evaporation technology on the glass substrate. The transmittance and surface morphology of the films were examined. The anti-reflection coating structure was optimized considering AMI. 5 spectrum and the spectroscopy response band of CdS/CdTe thin film solar cells through TFCALC software simulation. Then the optimized anti-reflection coatings were prepared on the CdTe thin film solar cells. It was found that the quantum efficiency of solar cells with anti-reflection coatings increase by 7. 3% than without, and the photoelectric conversion efficiency increased from 12. 5% to 13. 3%.%使用减反射膜层是提高太阳电池短路电流密度进而提高电池转换效率的有效手段之一.针对CdTe薄膜太阳电池的光谱响应范围,基于AM1.5辐照光谱,优化设计了MgF2/H4/Al2O3结构的减反射薄膜,使用电子束蒸发技术制备了该减反射膜,使用椭圆偏振仪、紫外/可见分光光度计、原子力显微镜分别测量了所制备薄膜的光学性质和表面形貌,对比分析了膜系结构理论模拟与实验测量结果.结果表明,使用该减反射薄膜后,电池的量子效率提高了7.3%;光电转换效率从12.5%提高到13.3%.

  15. Multi-layer coatings

    Energy Technology Data Exchange (ETDEWEB)

    Maghsoodi, Sina; Brophy, Brenor L.; Abrams, Ze' ev R.; Gonsalves, Peter R.

    2016-06-28

    Disclosed herein are coating materials and methods for applying a top-layer coating that is durable, abrasion resistant, highly transparent, hydrophobic, low-friction, moisture-sealing, anti-soiling, and self-cleaning to an existing conventional high temperature anti-reflective coating. The top coat imparts superior durability performance and new properties to the under-laying conventional high temperature anti-reflective coating without reducing the anti-reflectiveness of the coating. Methods and data for optimizing the relative thickness of the under-layer high temperature anti-reflective coating and the top-layer thickness for optimizing optical performance are also disclosed.

  16. a-SiCxNy:H thin films for applications in solar cells as passivation and antireflective coatings

    Science.gov (United States)

    Swatowska, Barbara; Kluska, Stanisława; Lewińska, Gabriela; Golańska, Julia; Stapiński, Tomasz

    2016-12-01

    Amorphous a-SiCxNy:H thin films may be an alternative to a-Si:N:H coatings which are commonly used in silicon solar cells. This material was obtained by PECVD (13.56 MHz) method. The reaction gases used: silane, methane, nitrogen and ammonia. The structure of the layers were investigated by scanning electron microscopy (SEM) and infrared spectroscopy (FTIR). IR absorption spectra of a-SiCxNy:H layers confirmed the presence of various hydrogen bonds - it is important for passivation of Si structural defects. The ellipsometric measurements were implemented to determine the thickness of layers d, refractive index n, extinction coefficient k and energy gap Eg. The values of the energy gap of a-SiCxNy:H layers are in the range from 1.89 to 4.34 eV. The correlation between energy gap of materials and refractive index was found. Generally the introduction of N and/or C into the amorphous silicon network rapidly increases the Eg values.

  17. Injection moulding antireflective nanostructures

    DEFF Research Database (Denmark)

    Christiansen, Alexander Bruun; Clausen, Jeppe Sandvik; Mortensen, N. Asger;

    index of the nanostructured surfaces was estimated from atomic force micrographs and the theoretical reflectance was calculated using the transfer matrix method and effective medium theory. The measured reflectance shows good agreement with the theory of graded index antireflective nanostructures...

  18. Nanotip Carpets as Antireflection Surfaces

    Science.gov (United States)

    Bae, Youngsam; Mobasser, Sohrab; Manohara, Harish; Lee, Choonsup

    2008-01-01

    Carpet-like random arrays of metal-coated silicon nanotips have been shown to be effective as antireflection surfaces. Now undergoing development for incorporation into Sun sensors that would provide guidance for robotic exploratory vehicles on Mars, nanotip carpets of this type could also have many uses on Earth as antireflection surfaces in instruments that handle or detect ultraviolet, visible, or infrared light. In the original Sun-sensor application, what is required is an array of 50-micron-diameter apertures on what is otherwise an opaque, minimally reflective surface, as needed to implement a miniature multiple-pinhole camera. The process for fabrication of an antireflection nanotip carpet for this application (see Figure 1) includes, and goes somewhat beyond, the process described in A New Process for Fabricating Random Silicon Nanotips (NPO-40123), NASA Tech Briefs, Vol. 28, No. 1 (November 2004), page 62. In the first step, which is not part of the previously reported process, photolithography is performed to deposit etch masks to define the 50-micron apertures on a silicon substrate. In the second step, which is part of the previously reported process, the non-masked silicon area between the apertures is subjected to reactive ion etching (RIE) under a special combination of conditions that results in the growth of fluorine-based compounds in randomly distributed formations, known in the art as "polymer RIE grass," that have dimensions of the order of microns. The polymer RIE grass formations serve as microscopic etch masks during the next step, in which deep reactive ion etching (DRIE) is performed. What remains after DRIE is the carpet of nano - tips, which are high-aspect-ratio peaks, the tips of which have radii of the order of nanometers. Next, the nanotip array is evaporatively coated with Cr/Au to enhance the absorption of light (more specifically, infrared light in the Sun-sensor application). The photoresist etch masks protecting the apertures

  19. Nanostructured antireflective bilayers: Optical design and preparation

    Energy Technology Data Exchange (ETDEWEB)

    Detrich, Ádám [Budapest University of Technology and Economics, Department of Physical Chemistry and Materials Science, Centre for Colloid Chemistry, H-1521 Budapest (Hungary); Nagy, Norbert [Research Centre for Natural Sciences (MTA TTK), Institute for Technical Physics and Materials Science (MFA), P.O. Box 49, H-1525 Budapest (Hungary); Nyári, Mária; Albert, Emőke; Zámbó, Dániel [Budapest University of Technology and Economics, Department of Physical Chemistry and Materials Science, Centre for Colloid Chemistry, H-1521 Budapest (Hungary); Hórvölgyi, Zoltán, E-mail: zhorvolgyi@mail.bme.hu [Budapest University of Technology and Economics, Department of Physical Chemistry and Materials Science, Centre for Colloid Chemistry, H-1521 Budapest (Hungary)

    2014-05-01

    We show different methods for tailoring and fabrication of various cost-effective antireflective nanocoatings on transparent and non-transparent substrates. The main purpose was to prepare coatings with decreased reflectance in the full visible wavelength range using simple wet layer deposition techniques. Structure of coatings was designed by optical simulations applying simplified calculations. The refractive index of substrates was also considered for the calculations. The advantageous optical properties were achieved by bilayered structures combining compact and porous sol–gel derived oxide layers and nanoparticulate films. The bilayered structures enhance the flexibility of design by not only the selection of the layer thicknesses but also by different ways of adjusting the effective refractive index of the layers. Furthermore, chemical stability of the coatings was also investigated. The optical and structural properties of prepared films and bilayered coatings were studied by UV–vis spectroscopy and scanning electron microscopy, respectively. The transmittance of coated glass substrates was above 97.5%, while the reflectance of coated silicon substrates was below 4% between 450 nm and 900 nm. - Highlights: • Designed antireflective bilayered coatings on glass and silicon. • Simple, colloid chemical approaches to preparation. • Favorable optical properties by combining compact and porous oxide layers. • Different ways for adjusting the effective refractive index. • Strong chemical resistance against acidic effects.

  20. Antireflection design concepts with equivalent layers.

    Science.gov (United States)

    Schallenberg, Uwe B

    2006-03-01

    Some novel concepts of designing antireflection (AR) coatings with equivalent layers are presented. As an introduction, essential papers concerning thin-film optics and AR designs are cited, and the AR problem and a previously introduced AR-hard design type are discussed. Based on the known matrix formalism, a potential AR region, an equivalent stack index, and an equivalent substrate index are defined to use the theory of stop-band suppression as a starting point for the design of broadband AR coatings. The known multicycle AR design type is identified as a typical solution to the AR problem if the presented approach is used.

  1. Space qualification of an antireflection coating on the surface of a ruled grating prism: increasing the throughput of the single-object slitless spectroscopy mode of NIRISS onboard JWST

    Science.gov (United States)

    Albert, Loïc.; Doyon, René; Kuzmenko, Paul J.; Little, Steve L.; Enzor, Greg S.; Maszkiewicz, Michael

    2014-07-01

    Grating prisms (grism) designed for near-infrared spectroscopy typically make use of high-refractive index materials such as zinc selenide (ZnSe), at the expense of large Fresnel losses ( 18%). Part of the loss can be recovered by using anti-reflection (AR) coatings. The technique is however considered risky when applied on the ruled surface of a grating, especially for a space application at cryogenic temperature. Such a grism, made of ZnSe and machined at Lawrence Livermore National Laboratory (LLNL) is mounted in the Near-Infrared Slitless Spectrograph (NIRISS) onboard the James Webb Space Telescope (JWST). Its Single Object Slitless Spectrograph (SOSS) observing mode uses the ZnSe grism and a cross-dispersing prism to produce R=700 spectra in orders 1 and 2 to cover the 0.6 to 2.5 microns spectral domain. The ZnSe grism is blazed at 1.23 microns, has a density of 54 lines/mm and its triangular grooves have a depth of 700 nm, a base of 18 microns, with facets angled at 1.9 degrees. Here, an AR coating produced by Thin Film Lab (TFL) and deposited on the ruled surface of a ZnSe grism sample was space qualified. Atomic force microscopy (AFM) showed no groove profile change pre/post coating despite the large relative thickness of the AR coating to that of the groove depth ( 35%). Also, the wavefront error map remained almost unchanged at lambda/8 (peak-to-valley at 632 nm) and survived unscathed through a series of three cryogenic cycles to 20 K. Finally, the transmission gain across our operating spectral range was almost as high as that for a unruled surface covered with the same AR coating (10-15%).

  2. Review of 1064-nm damage tests of electron-beam deposited Ta/sub 2/O/sub 5//SiO/sub 2/ antireflection coatings

    Energy Technology Data Exchange (ETDEWEB)

    Milam, D.; Rainer, F.; Lowdermilk, W.H.; Swain, J.E.; Carniglia, C.K.; Hart, T.T.

    1981-12-18

    Damage tests of Ta/sub 2/O/sub 5//SiO/sub 2/ antireflection films deposited under a variety of conditions showed that thresholds of films deposited at 175/sup 0/C were greater than thresholds of films deposited at either 250/sup 0/C or 325/sup 0/C. Deposition at high rate and low oxygen pressure produced highly absorptive films with low thresholds. Thresholds did not correlate with film reflectivity or net stress in the films, and correlated with film absorption only when the film absorption was greater than 10/sup 4/ ppM. Baking the films for four hours at 400/sup 0/C reduced film absorption, altered net film stress, and produced an increase in the average damage threshold.

  3. 晶体硅太阳电池减反射膜的研究%Research on Antireflection Coating of Crystalline Silicon Solar Cells

    Institute of Scientific and Technical Information of China (English)

    赵萍; 麻晓园; 邹美玲

    2011-01-01

    在太阳电池表面形成一层减反射薄膜是提高太阳电池的光电转换效率比较可行且降低成本的方法.应用PECVD(等离子体增强化学气相沉积)系统,采用SiH4和NH3气源以制备氮化硅薄膜.研究探索了PECVD生长氮化硅薄膜的基本物化性质以及在沉积过程中反应压强、反应温度、硅烷氨气流量比和微波功率对薄膜性质的影响.通过大量实验,分析了氮化硅薄膜的相对最佳沉积参数,并得出制作减反射膜的优化工艺.%Depositing antireflection films on solar cells is the most doable way to improve conversion efficiency of solar cells, which can also debase the cost of solar cells. The PECVD (Plasma Enhanced Chemical Vapor Deposition) system and the reactants of silane and ammonia are applied to fabricating SiN thin film. The effects of reaction temperature, the flow ratio of silane over ammoma and the microwave power on the film character are researched. The effects of post deposition annealing on solar cell materials are also discussed primarily. The optimal relative deposition parameters are investigated and the optimized processes of antireflection fabrication are attained with plenty of experienments.

  4. Superluminal propagation and broadband omnidirectional antireflection in optical reflectionless potentials

    CERN Document Server

    Thekkekara, L V; Kasture, Sachin; Mulay, Gajendra; Gupta, S Dutta

    2013-01-01

    Reflectionless potentials (RPs) represent a class of potentials that offer total transmission in the context of one dimensional scattering. Optical realization of RPs in stratified medium can exhibit broadband omnidirectional antireflection property. In addition to the antireflection property, RPs are also expected to demonstrate negative delay. We designed refractive index profiles conforming to RPs and realize them in stratified media consisting of Al2O3 and TiO2 heterolayers. In these structures we observed < 1% reflection over the broad wavelength range of 350 nm to 2500 nm for angles of incidence 0 - 50 degrees. The observed reflection and transmission response of RPs are polarization independent. A negative delay of about 31 fsec with discernible pulse narrowing was observed in passage through two RPs. These RPs can be interesting for optical instrumentation as broadband, omni-directional antireflection coatings as well as in pulse control and transmission applications like delay lines.

  5. Antireflection Pyrex envelopes for parabolic solar collectors

    Science.gov (United States)

    McCollister, H. L.; Pettit, R. B.

    1983-11-01

    Antireflective (AR) coatings, applied to the glass envelopes used in parabolic trough solar collectors around the receiver tube in order to reduce thermal losses, can increase solar transmittance by 7 percent. An AR surface has been formed on Pyrex by first heat treating the glass to cause a compositional phase separation, removing a surface layer after heat treatment through the use of a preetching solution, and finally etching in a solution that contains hydrofluorosilic and ammonium bifluoride acids. AR-coated samples with solar transmittance values of more than 0.97, by comparison to an untreated sample value of 0.91, have been obtained for the 560-630 C range of heat treatment temperatures. Optimum values have also been determined for the other processing parameters.

  6. Antireflective surface patterned by rolling mask lithography

    Science.gov (United States)

    Seitz, Oliver; Geddes, Joseph B.; Aryal, Mukti; Perez, Joseph; Wassei, Jonathan; McMackin, Ian; Kobrin, Boris

    2014-03-01

    A growing number of commercial products such as displays, solar panels, light emitting diodes (LEDs and OLEDs), automotive and architectural glass are driving demand for glass with high performance surfaces that offer anti-reflective, self-cleaning, and other advanced functions. State-of-the-art coatings do not meet the desired performance characteristics or cannot be applied over large areas in a cost-effective manner. "Rolling Mask Lithography" (RML™) enables highresolution lithographic nano-patterning over large-areas at low-cost and high-throughput. RML is a photolithographic process performed using ultraviolet (UV) illumination transmitted through a soft cylindrical mask as it rolls across a substrate. Subsequent transfer of photoresist patterns into the substrate is achieved using an etching process, which creates a nanostructured surface. The current generation exposure tool is capable of patterning one-meter long substrates with a width of 300 mm. High-throughput and low-cost are achieved using continuous exposure of the resist by the cylindrical photomask. Here, we report on significant improvements in the application of RML™ to fabricate anti-reflective surfaces. Briefly, an optical surface can be made antireflective by "texturing" it with a nano-scale pattern to reduce the discontinuity in the index of refraction between the air and the bulk optical material. An array of cones, similar to the structure of a moth's eye, performs this way. Substrates are patterned using RML™ and etched to produce an array of cones with an aspect ratio of 3:1, which decreases the reflectivity below 0.1%.

  7. 真空蒸镀氟化镁增透膜的厚度与均匀性控制%Thickness and Uniformity Control of Vacuum Evaporated Magnesium Fluoride Antireflection Coatings

    Institute of Scientific and Technical Information of China (English)

    温才; 令勇洲; 李文俊; 刘虹; 寇采懿; 蒋耀; 唐金龙

    2012-01-01

    For preparing high efficiency MgF2 antireflection coatings, the thickness and uniformity control of the MgF2 film evaporated by thermal resistance and electron beam were studied. On the basis of principles of antirc flection coatings and vacuum evaporation, many factors such as the weight and physical form of raw materials and the distance between evaporation source and substrates were carefully studied. The results show that for the raw materials in small particles or with low melting point, thermal resistance evaporation can not only control more easily but also avoid the raw material pollution comparing with electron beam evaporation; the actual weight of the evaporated raw materials is approximately linear to the film thickness;although the actual weight is equal, the thickness of film evaporated from the raw materials in polycrystalline particles form is higher than that in powder form; the thickness and uniformity of the film are higher for the substrates in the censer than those in the side of the rotating disk. At last, these experimental results are well explained by the evaporation model of the small plane source for rotating spherical fixture.%基于光学增透膜与真空蒸发镀膜的基本原理,从MgF2原料状态、原料蒸镀质量、蒸发源与基片间距等方面,研究了热电阻和电子束蒸镀的MgF2薄膜厚度与其均匀性的控制工艺,以制备出高效的MgF2增透膜.结果表明:对于颗粒度较小或熔点较低的原料,热电阻比电子束蒸镀更易控制,并可避免原料污染;原料实际蒸镀质量与膜厚呈较好的线性关系;实际蒸镀质量相同的多晶颗粒与粉末状原料相比,前者蒸镀膜更厚;基片置于旋转工转盘中心比其侧部区域蒸镀膜更厚、均匀性更好.最后利用旋转球面夹具的小平面源蒸发模型很好地解释了上述实验结果.

  8. Optical coating and nano-structuring on plastics

    Institute of Scientific and Technical Information of China (English)

    U.Schulz; P.Munzert; A.Kaless; N.Kaiser

    2005-01-01

    The coating of plastics for optical applications is intended to improve the mechanical durability of soft polymers and to serve an antireflection function. Usually a classic four-layer antireflection system is added on top of a single-layer hard coating. With needle optimisation,an alternative coating design has been developed. Plasma ion assisted deposition was used to deposit coatings upon polymers. Uniform antireflection and high scratch resistance have been achieved.

  9. BDS Thin Film UV Antireflection Laser Damage Competition

    Energy Technology Data Exchange (ETDEWEB)

    Stolz, C J

    2010-10-26

    UV antireflection coatings are a challenging coating for high power laser applications as exemplified by the use of uncoated Brewster's windows in laser cavities. In order to understand the current laser resistance of UV AR coatings in the industrial and university sectors, a double blind laser damage competition was performed. The coatings have a maximum reflectance of 0.5% at 355 nm at normal incidence. Damage testing will be performed using the raster scan method with a 7.5 ns pulse length on a single testing facility to facilitate direct comparisons. In addition to the laser resistance results, details of deposition processes and coating materials will also be shared.

  10. Development of diffractive antireflection structures on ZnSe for high power CO II laser applications

    Science.gov (United States)

    Reversat, Fabien; Berthou, Thierry; Tisserand, Stéphane; Dupuy, Lionel; Gautier, Sophie; Muys, Peter; Delbeke, Danae; Grojo, David; Laraichi, Mohammed; Delaporte, Philippe

    2008-04-01

    The unavoidable absorption of thin films used in antireflective coatings forms a permanent bottleneck in the development of optics for high power laser applications. A valid alternative would be the micro-structuring of the optics surface, realizing a diffraction grating which emulates the functioning of an Anti-Reflection thin film layer. Due to the absence of film material, this diffractive structure would not contribute to the overall absorption of the optics. This paper investigates the practical limits of this strategy, applied to zinc selenide as low absorption infrared substrate material.

  11. Development of new maskless manufacturing method for anti-reflection structure and application to large-area lens with curved surface

    Science.gov (United States)

    Yamamoto, Kazuya; Takaoka, Toshimitsu; Fukui, Hidetoshi; Haruta, Yasuyuki; Yamashita, Tomoya; Kitagawa, Seiichiro

    2016-03-01

    In general, thin-film coating process is widely applied on optical lens surface as anti-reflection function. In normal production process, at first lens is manufactured by molding, then anti-reflection is added by thin-film coating. In recent years, instead of thin-film coating, sub-wavelength structures adding on surface of molding die are widely studied and development to keep anti-reflection performance. As merits, applying sub-wavelength structure, coating process becomes unnecessary and it is possible to reduce man-hour costs. In addition to cost merit, these are some technical advantages on this study. Adhesion of coating depends on material of plastic, and it is impossible to apply anti-reflection function on arbitrary surface. Sub-wavelength structure can solve both problems. Manufacturing method of anti-reflection structure can be divided into two types mainly. One method is with the resist patterning, and the other is mask-less method that does not require patterning. What we have developed is new mask-less method which is no need for resist patterning and possible to impart an anti-reflection structure to large area and curved lens surface, and can be expected to apply to various market segments. We report developed technique and characteristics of production lens.

  12. Tailored antireflective biomimetic nanostructures for UV applications

    Energy Technology Data Exchange (ETDEWEB)

    Morhard, Christoph; Pacholski, Claudia; Spatz, Joachim P [Department of New Materials and Biosystems, Max Planck Institute for Metals Research, Heisenbergstrasse 3, D-70569 Stuttgart (Germany); Lehr, Dennis; Brunner, Robert; Helgert, Michael [Carl Zeiss Jena GmbH, Technology Center, Carl-Zeiss-Promenade 10, D-07745 Jena (Germany); Sundermann, Michael, E-mail: Pacholski@mf.mpg.de [Carl Zeiss Jena GmbH, Technology Center, Carl-Zeiss-Strasse 56, D-73447 Oberkochen (Germany)

    2010-10-22

    Antireflective surfaces composed of biomimetic sub-wavelength structures that employ the 'moth eye principle' for reflectance reduction are highly desirable in many optical applications such as solar cells, photodetectors and laser optics. We report an efficient approach for the fabrication of antireflective surfaces based on a two-step process consisting of gold nanoparticle mask generation by micellar block copolymer nanolithography and a multi-step reactive ion etching process. Depending on the RIE process parameters nanostructured surfaces with tailored antireflective properties can easily be fabricated that show optimum performance for specific applications.

  13. Coatings and Tints of Spectacle Lenses

    OpenAIRE

    H. Zeki Büyükyıldız

    2012-01-01

    Spectacle lenses are made of mineral or organic (plastic) materials. Various coatings and tints are applied to the spectacle lenses according to the characteristic of the lens material, and for the personal needs and cosmetic purpose. The coatings may be classified in seven groups: 1) Anti-reflection coatings, 2) Hard coatings, 3) Clean coat, 4) Mirror coatings, 5) Color tint coating (one of coloring processes), 6) Photochromic coating (one of photochromic processes), and 7) Anti-fog...

  14. One step antiglare sol-gel coating for screens by sol-gel techniques

    OpenAIRE

    Schelle, Christian; Mennig, Martin; Krug, Herbert; Jonschker, Gerhard; Schmidt, Helmut K.

    1997-01-01

    Anti-reflection coatings on glass substrates were prepared by the application of sol-gel coatings of silica containing crystalline tin oxide particles. The sol was coated on commercially available float glass by dip-coating and spin-coating techniques. Increasing the surface roughness of the float glass (factor of 50) by a particulate coating material resulted in anti-reflection effects comparable to frosted glass. Haze and clarity, which are a measure for the contrast and definition of an op...

  15. Texturing of the Silicon Substrate with Nanopores and Si Nanowires for Anti-reflecting Surfaces of Solar Cells

    Directory of Open Access Journals (Sweden)

    A.A. Druzhinin

    2015-06-01

    Full Text Available The paper presents the prospects of obtaining a functional multi-layer anti-reflecting coating of the front surface of solar cells by texturing the surface of the silicon by electrochemical etching. The physical model of the "Black Si" coating with discrete inhomogeneity of the refractive index and technological aspects of producing of "Black Si" functional anti-reflecting coatings were presented. The investigation results of the spectral characteristics of the obtained multilayer multiporous "Black Si" coatings for silicon solar cells made by electrochemical etching are presented. The possibility of creating the texture on a silicon wafer surface using silicon nanowires and ordered nanopores obtained by metal-assisted chemical etching was shown.

  16. Optical Curtain Effect: Extraordinary Optical Transmission Enhanced by Antireflection

    CERN Document Server

    Cui, Yanxia; Lin, Yinyue; Li, Guohui; Hao, Yuying; He, Sailing; Fang, Nicholas X

    2012-01-01

    In this paper, we employ an antireflective coating which comprises of inverted pi shaped metallic grooves to manipulate the behaviour of a TM-polarized plane wave transmitted through a periodic nanoslit array. At normal incidence, such scheme can not only retain the optical curtain effect in the output region, but also generate the extraordinary transmission of light through the nanoslits with the total transmission efficiency as high as 90%. Besides, we show that the spatially invariant field distribution in the output region as well as the field distribution of resonant modes around the inverted pi shaped grooves can be reproduced immaculately when the system is excited by an array of point sources beneath the inverted pi shaped grooves. In further, we investigate the influence of center-groove and side-corners of the inverted pi shaped grooves on suppressing the reflection of light, respectively. Based on our work, it shows promising potential in applications of enhancing the extraction efficiency as well ...

  17. Synthesis of Neutral SiO/TiO Hydrosol and Its Application as Antireflective Self-Cleaning Thin Film

    Directory of Open Access Journals (Sweden)

    Chiahung Huang

    2012-01-01

    Full Text Available A neutral SiO2/TiO2 composite hydrosol was prepared by a coprecipitation-peptization method using titanium tetrachloride and silicon dioxide hydrosol as precursors. It is not only an antireflective self-cleaning coating material but also an environmental-benign material. Even heated at 700°C for 5 minutes in the tempering process, the as-prepared SiO2/TiO2 thin film still demonstrated antireflection and photocatalytic self-cleaning effect. The SiO2/TiO2 thin film increased near 2% of transmittance; however, the TiO2 thin film decreased 5% of transmittance at least. In addition to antireflection, the SiO2/TiO2 thin film decomposed the surface coated oleic acid under ultraviolet light and showed superhydrophilicity under dark for two days. The SiO2/TiO2 thin film also showed good photocatalytic degradation of methylene blue. With these antireflection, persistent superhydrophilicity, and photocatalytic self-cleaning effects, this prepared neutral SiO2/TiO2 hydrosol would be a good coating material for tempered glass and other building materials.

  18. Broadband and omnidirectional anti-reflection layer for III/V multi-junction solar cells

    CERN Document Server

    Diedenhofen, Silke L; Haverkamp, Erik; Bauhuis, Gerard; Schermer, John; Rivas, Jaime Gómez; 10.1016/j.solmat.2012.02.022

    2012-01-01

    We report a novel graded refractive index antireflection coating for III/V quadruple solar cells based on bottom-up grown tapered GaP nanowires. We have calculated the photocurrent density of an InGaP-GaAs-InGaAsP-InGaAs solar cell with a MgF2/ZnS double layer antireflection coating and with a graded refractive index coating. The photocurrent density can be increased by 5.9 % when the solar cell is coated with a graded refractive index layer with a thickness of 1\\mu m. We propose to realize such a graded refractive index layer by growing tapered GaP nanowires on III/V solar cells. For a first demonstration of the feasibility of the growth of tapered nanowires on III/V solar cells, we have grown tapered GaP nanowires on AlInP/GaAs substrates. We show experimentally that the reflection from the nanowire coated substrate is reduced and that the transmission into the substrate is increased for a broad spectral and angular range.

  19. Study of an antireflection surface constructed of controlled ZnO nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Ren-Jei, E-mail: rjchung@ntut.edu.tw [Department of Chemical Engineering and Biotechnology, National Taipei University of Technology (Taipei Tech), Taipei 10608, Taiwan, ROC (China); Lin, Zih-Cian [Department of Chemical Engineering and Biotechnology, National Taipei University of Technology (Taipei Tech), Taipei 10608, Taiwan, ROC (China); Lin, Chin-An; Lai, Kun-Yu [Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan, ROC (China); Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan, ROC (China)

    2014-11-03

    Zinc oxide (ZnO) nanostructures were fabricated on Si wafers using a hydrothermal method. By adjusting the spin-coating speed and annealing time for the zinc acetate thin films used as a seed layer, the density of ZnO nanorods (NRs) was controlled. In addition, it was found that the morphology of the NRs evolved from a wire-like geometry to a tower-like geometry with an increasing concentration of ascorbic acid. The surface reflectance of the ZnO NR layers with various textures was investigated. The results indicated that NRs effectively enhanced light trapping and further reduced Fresnel reflection due to the significant grading in the refractive index, avoiding the abrupt transition at the air/Si interface. The total reflectance on the coated surface can be as low as 11%, which is 3 times lower than that of polished Si. The optimized design of nanostructured ZnO surfaces for antireflection coatings will greatly improve the performance of optoelectronic devices. - Highlights: • Nanotructured ZnO was prepared to serve as an anti-reflection coating. • The geometries of sol–gel prepared ZnO were controlled. • ZnO nanorod, nanoneedle and nanotower arrays were fabricated. • The light reflectance of the nanostructures was much lower than that of bare Si.

  20. Triple Layer Antireflection Design Concept for the Front Side of c-Si Heterojunction Solar Cell Based on the Antireflective Effect of nc-3C-SiC:H Emitter Layer

    Directory of Open Access Journals (Sweden)

    Erick Omondi Ateto

    2016-01-01

    Full Text Available We investigated the antireflective (AR effect of hydrogenated nanocrystalline cubic silicon carbide (nc-3C-SiC:H emitter and its application in the triple layer AR design for the front side of silicon heterojunction (SHJ solar cell. We found that the nc-3C-SiC:H emitter can serve both as an emitter and antireflective coating for SHJ solar cell, which enables us to realize the triple AR design by adding one additional dielectric layer to normally used SHJ structure with a transparent conductive oxide (TCO and an emitter layer. The optimized SHJ structure with the triple layer AR coating (LiF/ITO/nc-3C-SiC:H exhibit a short circuit current density (Jsc of 38.65 mA/cm2 and lower reflectivity of about 3.42% at wavelength range of 300 nm–1000 nm.

  1. Epitaxial growth of an antireflective, conductive, graded index ITO nanowire layer

    Directory of Open Access Journals (Sweden)

    Colm eO'Dwyer

    2013-10-01

    Full Text Available Nanoporous and nanostructured films, assemblies and arrangements are important from an applied point of view in microelectronics, photonics and optical materials. The ability to minimize reflection, control light output and use contrast and variation of the refractive index to modify photonic characteristics can provide routes to enhanced photonic crystal devices, omnidirectional reflectors, antireflection coatings and broadband absorbing materials. This work shows how multiscale branching of defect-free ITO NWs grown as a layer with a graded refractive index improves antireflection properties and shifts the transparency window into the near-infrared (NIR. The measurements confirm the structural quality and growth mechanism of the NW layer without any heterogeneous seeding for NW growth. Optical reflectance measurements confirm broadband antireflection down to <5% between 1.3-1.6 um which is tunable with the NW density. The work also outlines how the suppression of the Burstein-Moss shifts using refractive index variation allows transparency in a conductive NW layer into NIR range.

  2. Durable superhydrophobic and antireflective surfaces by trimethylsilanized silica nanoparticles-based sol-gel processing.

    Science.gov (United States)

    Manca, Michele; Cannavale, Alessandro; De Marco, Luisa; Aricò, Antonino S; Cingolani, Roberto; Gigli, Giuseppe

    2009-06-02

    We present a robust and cost-effective coating method to fabricate long-term durable superhydrophobic andsimultaneouslyantireflective surfaces by a double-layer coating comprising trimethylsiloxane (TMS) surface-functionalized silica nanoparticles partially embedded into an organosilica binder matrix produced through a sol-gel process. A dense and homogeneous organosilica gel layer was first coated onto a glass substrate, and then, a trimethylsilanized nanospheres-based superhydrophobic layer was deposited onto it. After thermal curing, the two layers turned into a monolithic film, and the hydrophobic nanoparticles were permanently fixed to the glass substrate. Such treated surfaces showed a tremendous water repellency (contact angle = 168 degrees ) and stable self-cleaning effect during 2000 h of outdoor exposure. Besides this, nanotextured topology generated by the self-assembled nanoparticles-based top layer produced a fair antireflection effect consisting of more than a 3% increase in optical transmittance.

  3. A novel self-cleaning and anti-reflective multi-layer for thin-film solar PV module

    Energy Technology Data Exchange (ETDEWEB)

    Wong, K.L.; Shiue, J.D. [Kun-Shan Univ., Yung-Kung City, Taiwan (China). Clean Energy Center; Li, M.; Huang, M.C. [NanoWinTechnology Co., Ltd., Taiwan (China); Fu, Y.S.; Wei, S.S. [National Univ. of Tainan, Tainan, Taiwan (China)

    2007-07-01

    Titanium dioxide (TiO{sub 2}) acts as a photocatalyst, and can accelerate the decomposition of organic particulates and airborne pollutants that gather on solar arrays. In this study, a TiO{sub 2} film was coated on the outside surface of sodium glass in order to increase the self-cleaning ability of solar cells. DC magnetic sputtering was used to coat multi-layer thin films of silicon nitrides in order to increase their antireflective capabilities. The TiO{sub 2} thin film was fabricated using the sol-gel method. Optical properties of the microstructure and composition of the films were characterized using UV-V spectroscopy. Results showed that the best anti-reflection spectrum of the TiO{sub 2} was between 700 and 800 nm. Average transmission rates were 3.54 per cent higher than those observed in slide glass samples. It was concluded that overlapped titanium dioxide/silicon nitride thin films can achieve a very good anti-reflective effect as well as self-cleaning ability in the range of 400-800 nm. 9 refs., 4 figs.

  4. Design of optical coatings

    Science.gov (United States)

    Gunkel, Claus W.

    1990-08-01

    A highly sophisticated antireflection coating and a cut-on-filter - designed by the Leitz program "RDP" - will be pointed out. The program runs on a VAX 8530 and allows to calculate reflectance, transmittance and phase of randomly polarized light which interacts with marginal surfaces. The number of layers is not limited. Some or even all layers are allowed to be anistropic. Up to four layers may be inhomogeneous both in refractive indices and absorption constants. At a time two thicknesses, two refractive indices and absorption constants as well as the angles of incidence may be varied independently in each run. The calculated values will be compared with the results of measurements. The antireflection coating is evaporated in a Balzers high vacuum evaporation plant, controlled by the process unit BPU 420, whereas the cut-on filter is evaporated in a Leybold box coater with Leycom III and two electron-beam guns.

  5. Questionable effects of antireflective coatings on inefficiently cooled solar cells

    DEFF Research Database (Denmark)

    Akhmatov, Vladislav; Galster, Georg; Larsen, Esben

    1998-01-01

    of the output power and efficiency curves throughout the day the coherence between technical parameters of the solar cells and the climate in the operation region is observed and examined. It is shown how the drop in output power around noon can be avoided by fitting technical parameters of the solar cells......A model for temperature effects in p-n junction solar cells is introduced. The temperature of solar cells and the losses in the solar cell junction region caused by elevating temperature are discussed. The model developed is examined for low-cost silicon solar cells. In order to improve the shape...

  6. Laser processing of solar cells with anti-reflective coating

    Energy Technology Data Exchange (ETDEWEB)

    Harley, Gabriel; Smith, David D.; Dennis, Tim; Waldhauer, Ann; Kim, Taeseok; Cousins, Peter John

    2016-02-16

    Contact holes of solar cells are formed by laser ablation to accommodate various solar cell designs. Use of a laser to form the contact holes is facilitated by replacing films formed on the diffusion regions with a film that has substantially uniform thickness. Contact holes may be formed to deep diffusion regions to increase the laser ablation process margins. The laser configuration may be tailored to form contact holes through dielectric films of varying thicknesses.

  7. Fabrication of sub-wavelength antireflective structure to enhance the efficiency of InGaAs solar cells

    Directory of Open Access Journals (Sweden)

    Yen-Yu Chou

    2014-08-01

    Full Text Available Large differences in the refractive index between semiconductors (Si, GaAs, etc. and air produces considerable Fresnel loss, which can seriously hinder the absorption of sunlight by photovoltaic solar cells. This study presents a cost-effective roller nanoimprinting technique for the fabrication of sub-wavelength structures (SWSs as an alternative to conventional anti-reflective coatings used to reduce reflectance in triple-junction InGaP/InGaAs/Ge solar cells. The proposed nanoimprinting technology uses a soft PDMS mold duplicated from a hard silicon template, which is fabricated using PS sphere lithography and dry etching processes. To evaluate the anti-reflective performance of SWSs, we employed rigorous coupled wave analysis (RCWA to simulate the propagation of electromagnetic plane waves in a GaAs substrate. Simulation results demonstrated a considerable reduction in reflectance resulting from a gradual change in the refractive index provided by SWSs. Photoelectric conversion efficiency was also increased.

  8. Evaporated erbium oxide as an antireflective layer for C-Si solar cells

    Science.gov (United States)

    Alizadeh, Hossein; Bahardoust, Barzin; Gougam, Adel; Kherani, Nazir P.; Zukotynski, Stefan

    2009-08-01

    We report on the optical properties of erbium oxide thin films prepared by physical vapor deposition. The films were subjected to various rapid thermal annealing (RTA) treatments. The best result was obtained for samples annealed at 500 °C, where the ramp rate was 200 °C/s, zero soak time, and a cooling rate of 25 °C/s. The average reflection from this erbium oxide coated c-Si substrate, measured over a wavelength range of 300nm to 1100nm, is around 18% and 8% before and after annealing, respectively. The average transmission of erbium oxide on glass is 50 % and 90 % before and after annealing, respectively. Using this antireflection coating the short circuit current of a silicon base photovoltaic device increases by more than 40 %.

  9. Porous Nanomaterials for Ultrabroadband Omnidirectional Anti-Reflection Surfaces with Applications in High Concentration Photovoltaics

    KAUST Repository

    Yao, Yuan

    2016-12-06

    Materials for nanoporous coatings that exploit optimized chemistries and self-assembly processes offer capabilities to reach ≈98% transmission efficiency and negligible scattering losses over the broad wavelength range of the solar spectrum from 350 nm to 1.5 μm, on both flat and curved glass substrates. These nanomaterial anti-reflection coatings also offer wide acceptance angles, up to ±40°, for both s- and p-polarization states of incident light. Carefully controlled bilayer films have allowed for the fabrication of dual-sided, gradient index profiles on plano-convex lens elements. In concentration photovoltaics platforms, the resultant enhancements in the photovoltaics efficiencies are ≈8%, as defined by experimental measurements on systems that use microscale triple-junction solar cells. These materials and their applications in technologies that require control over interface reflections have the potential for broad utility in imaging systems, photolithography, light-emitting diodes, and display technologies.

  10. Sol-gel derived antireflective structures for applications in silicon solar cells

    Science.gov (United States)

    Karasiński, Paweł; Skolik, Marcin

    2016-12-01

    This work presents theoretical and experimental results of antireflective coatings (ARCs) obtained for applications in silicon solar cells. ARCs were derived from sol-gel process and dip-coated using silica (SiO2) and titania (TiO2). Theoretical results were obtained using 2×2 transfer matrix calculation method. Technological process of SiO2 and TiO2 thin film fabrication as well as measurement techniques are described in this paper. Strong correlation between theoretical and experimental data is demonstrated. It is shown, that weighted average reflection from a substrate can be reduced ten times with the use of SiO2/TiO2/Si double layer ARCs, when compared to a bare silica substrate.

  11. Optical thin films and coatings from materials to applications

    CERN Document Server

    Flory, Francois

    2013-01-01

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

  12. Coatings and Tints of Spectacle Lenses

    Directory of Open Access Journals (Sweden)

    H. Zeki Büyükyıldız

    2012-10-01

    Full Text Available Spectacle lenses are made of mineral or organic (plastic materials. Various coatings and tints are applied to the spectacle lenses according to the characteristic of the lens material, and for the personal needs and cosmetic purpose. The coatings may be classified in seven groups: 1 Anti-reflection coatings, 2 Hard coatings, 3 Clean coat, 4 Mirror coatings, 5 Color tint coating (one of coloring processes, 6 Photochromic coating (one of photochromic processes, and 7 Anti-fog coatings. Anti-reflection coatings reduce unwanted reflections from the lens surfaces and increase light transmission. Hard coatings are applied for preventing the plastic lens surface from scratches and abrasion. Hard coatings are not required for the mineral lenses due to their hardness. Clean coat makes the lens surface smooth and hydrophobic. Thus, it prevents the adherence of dust, tarnish, and dirt particles on the lens surface. Mirror coatings are applied onto the sunglasses for cosmetic purpose. Color tinted and photochromic lenses are used for sun protection and absorption of the harmful UV radiations. Anti-fog coatings make the lens surface hydrophilic and prevent the coalescence of tiny water droplets on the lens surface that reduces light transmission. (Turk J Ophthalmol 2012; 42: 359-69

  13. Simple, Fast, and Cost-Effective Fabrication of Wafer-Scale Nanohole Arrays on Silicon for Antireflection

    Directory of Open Access Journals (Sweden)

    Di Di

    2014-01-01

    Full Text Available A simple, fast, and cost-effective method was developed in this paper for the high-throughput fabrication of nanohole arrays on silicon (Si, which is utilized for antireflection. Wafer-scale polystyrene (PS monolayer colloidal crystal was developed as templates by spin-coating method. Metallic shadow mask was prepared by lifting off the oxygen etched PS beads from the deposited chromium film. Nanohole arrays were fabricated by Si dry etching. A series of nanohole arrays were fabricated with the similar diameter but with different depth. It is found that the maximum depth of the Si-hole was determined by the diameter of the Cr-mask. The antireflection ability of these Si-hole arrays was investigated. The results show that the reflection decreases with the depth of the Si-hole. The deepest Si-hole arrays show the best antireflection ability (reflection 600 nm, which was about 28 percent of the nonpatterned silicon wafer’s reflection. The proposed method has the potential for high-throughput fabrication of patterned Si wafer, and the low reflectivity allows the application of these wafers in crystalline silicon solar cells.

  14. Si/PEDOT:PSS Hybrid Solar Cells with Advanced Antireflection and Back Surface Field Designs

    Science.gov (United States)

    Sun, Yiling; Yang, Zhenhai; Gao, Pingqi; He, Jian; Yang, Xi; Sheng, Jiang; Wu, Sudong; Xiang, Yong; Ye, Jichun

    2016-08-01

    Molybdenum oxide (MoO3) is one of most suitable antireflection (AR) layers for silicon/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (Si/PEDOT:PSS) hybrid solar cells due to its well-matched refractive index (2.1). A simulation model was employed to predict the optical characteristics of Si/PEDOT:PSS hybrid solar cells with the MoO3 layers as antireflection coatings (ARCs), as well as to analyze the loss in current density. By adding an optimum thickness of a 34-nm-thick ARC of MoO3 on the front side and an effective rear back surface field (BSF) of phosphorus-diffused N + layer at the rear side, the hybrid cells displayed higher light response in the visible and near infrared regions, boosting a short-circuit current density ( J sc) up to 28.7 mA/cm2. The average power conversion efficiency (PCE) of the Si/PEDOT:PSS hybrid solar cells was thus increased up to 11.90 %, greater than the value of 9.23 % for the reference devices.

  15. Reflective solar coatings. (Latest citations from the NTIS bibliographic database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-01

    The bibliography contains citations concerning the research and development of solar reflective coatings. The use of reflective and antireflective coatings in solar mirrors, collectors, cells, and laser windows is discussed. Corrosion protection and protective coatings are emphasized. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  16. Fabrication of Antireflective Sub-Wavelength Structures on Silicon Nitride Using Nano Cluster Mask for Solar Cell Application

    Directory of Open Access Journals (Sweden)

    Lin Men-Ku

    2009-01-01

    Full Text Available Abstract We have developed a simple and scalable approach for fabricating sub-wavelength structures (SWS on silicon nitride by means of self-assembled nickel nanoparticle masks and inductively coupled plasma (ICP ion etching. Silicon nitride SWS surfaces with diameter of 160–200 nm and a height of 140–150 nm were obtained. A low reflectivity below 1% was observed over wavelength from 590 to 680 nm. Using the measured reflectivity data in PC1D, the solar cell characteristics has been compared for single layer anti-reflection (SLAR coatings and SWS and a 0.8% improvement in efficiency has been seen.

  17. Performance enhancement of pc-Si solar cells through combination of anti-reflection and light-trapping: Functions of AAO nano-grating

    Science.gov (United States)

    Wu, Lei; Zhang, Haiming; Qin, Feifei; Bai, Xiaogang; Ji, Ziye; Huang, Dan

    2017-02-01

    Anodic aluminium oxide (AAO) nanogratings are experimentally applied to polycrystalline silicon (pc-Si) solar cells at front surface to improve the light coupling. On the basis of the Fresnel Reflection Principle, the primary reflection loss can be reduced by multi-layer dielectric film with varing refactive index. And this multi-layer film is regarded as anti-reflection coating. An efficient light-trapping structure is significant in absorption enhancement of long wavelength band (around 900-1100 nm) for silicon solar cells. In this paper, we put AAO nanogratings on the front side of pc-Si solar cells to serve as anti-reflecting coating and light-trapping structure. The operation leads to light absorption enhancement eventually. Thanks to AAO nano-grating's structure parameters, the anti-reflecting and light-trapping effects are changeable. This is discussed in three aspects: AAO lattice period, AAO thickness and its pore diameter. Optical interaction between AAO nanograting and Ag electrodes is also discussed. We find an increase of short-circuit current density (1.32 mA/cm2) with SiNx:H/AAO complex coating. The relative power conversion efficiency obtains a growth about 2.2% points. Additionally, AAO nanogratings may facilitate carrier separation. This improves the performance of pc-Si solar cells in electrical aspect.

  18. An effective reflectance method for designing broadband antireflection films coupled with solar cells

    Institute of Scientific and Technical Information of China (English)

    Zhan Feng; He Ji-Fang; Shang Xiang-Jun; Li Mi-Feng; Ni Hai-Qiao; Xu Ying-Qiang; Niu Zhi-Chuan

    2012-01-01

    The solar spectrum covers a broad wavelength range,which requires that antireflection coating (ARC) is effective over a relatively wide wavelength range for more incident light coming into the cell.In this paper,we present two methods to measure the composite reflection of SiO2/ZnS double-layer ARC in the wavelength ranges of 300-870 nm (dualjunction) and 300-1850 nm (triple-junction),under the solar spectrum AM0.In order to give sufficient consideration to the ARC coupled with the window layer and the dispersion effect of the refractive index of each layer,we use multidimensional matrix data for reliable simulation.A comparison between the results obtained from the weighted-average reflectance (WAR) method commonly used and that from the effective-average reflectance (EAR) method introduced here shows that the optimized ARC through minimizing the effective-average reflectance is convenient and available.

  19. Optical coatings for laser fusion applications

    Energy Technology Data Exchange (ETDEWEB)

    Lowdermilk, W.H.; Milam, D.; Rainer, F.

    1980-04-24

    Lasers for fusion experiments use thin-film dielectric coatings for reflecting, antireflecting and polarizing surface elements. Coatings are most important to the Nd:glass laser application. The most important requirements of these coatings are accuracy of the average value of reflectance and transmission, uniformity of amplitude and phase front of the reflected or transmitted light, and laser damage threshold. Damage resistance strongly affects the laser's design and performance. The success of advanced lasers for future experiments and for reactor applications requires significant developments in damage resistant coatings for ultraviolet laser radiation.

  20. Surface Passivation and Antireflection Behavior of ALD on n-Type Silicon for Solar Cells

    Directory of Open Access Journals (Sweden)

    Ing-Song Yu

    2013-01-01

    Full Text Available Atomic layer deposition, a method of excellent step coverage and conformal deposition, was used to deposit TiO2 thin films for the surface passivation and antireflection coating of silicon solar cells. TiO2 thin films deposited at different temperatures (200°C, 300°C, 400°C, and 500°C on FZ n-type silicon wafers are in the thickness of 66.4 nm ± 1.1 nm and in the form of self-limiting growth. For the properties of surface passivation, Si surface is effectively passivated by the 200°C deposition TiO2 thin film. Its effective minority carrier lifetime, measured by the photoconductance decay method, is improved 133% at the injection level of  cm−3. Depending on different deposition parameters and annealing processes, we can control the crystallinity of TiO2 and find low-temperature TiO2 phase (anatase better passivation performance than the high-temperature one (rutile, which is consistent with the results of work function measured by Kelvin probe. In addition, TiO2 thin films on polished Si wafer serve as good ARC layers with refractive index between 2.13 and 2.44 at 632.8 nm. Weighted average reflectance at AM1.5G reduces more than half after the deposition of TiO2. Finally, surface passivation and antireflection properties of TiO2 are stable after the cofire process of conventional crystalline Si solar cells.

  1. Graded index and randomly oriented core-shell silicon nanowires for broadband and wide angle antireflection

    Directory of Open Access Journals (Sweden)

    P. Pignalosa

    2011-09-01

    Full Text Available Antireflection with broadband and wide angle properties is important for a wide range of applications on photovoltaic cells and display. The SiOx shell layer provides a natural antireflection from air to the Si core absorption layer. In this work, we have demonstrated the random core-shell silicon nanowires with both broadband (from 400nm to 900nm and wide angle (from normal incidence to 60º antireflection characteristics within AM1.5 solar spectrum. The graded index structure from the randomly oriented core-shell (Air/SiOx/Si nanowires may provide a potential avenue to realize a broadband and wide angle antireflection layer.

  2. Optical studies of multilayer dielectric-metal-dielectric coatings as applied to solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Demichelis, F.; Minetti-Mezzetti, E.; Perotto, V.

    1982-09-01

    A study of antireflection coatings for solar cells which provide maximum transmittance in the range of the spectral response of the cell and maximum reflectance in the IR portion of the spectrum of normally incident radiation is reported. Dielectric-metal-dielectric filters with a relatively low number of dielectric layers are designed as coatings for silicon and GaAs solar cells.

  3. Anti-reflective device having an anti-reflective surface formed of silicon spikes with nano-tips

    Science.gov (United States)

    Bae, Youngsam (Inventor); Manohara, Harish (Inventor); Mobasser, Sohrab (Inventor); Lee, Choonsup (Inventor)

    2011-01-01

    Described is a device having an anti-reflection surface. The device comprises a silicon substrate with a plurality of silicon spikes formed on the substrate. A first metallic layer is formed on the silicon spikes to form the anti-reflection surface. The device further includes an aperture that extends through the substrate. A second metallic layer is formed on the substrate. The second metallic layer includes a hole that is aligned with the aperture. A spacer is attached with the silicon substrate to provide a gap between an attached sensor apparatus. Therefore, operating as a Micro-sun sensor, light entering the hole passes through the aperture to be sensed by the sensor apparatus. Additionally, light reflected by the sensor apparatus toward the first side of the silicon substrate is absorbed by the first metallic layer and silicon spikes and is thereby prevented from being reflected back toward the sensor apparatus.

  4. Flexible-textured polydimethylsiloxane antireflection structure for enhancing omnidirectional photovoltaic performance of Cu(In,Ga)Se2 solar cells.

    Science.gov (United States)

    Kuo, Shou-Yi; Hsieh, Ming-Yang; Han, Hau-Vei; Lai, Fang-I; Chuang, Tsung-Yeh; Yu, Peichen; Lin, Chien-Chung; Kuo, Hao-Chung

    2014-02-10

    Because of the Sun's movement across the sky, broadband and omnidirectional light harvesting is a major development in photovoltaic technology. This study reports the fabrication and characterization of flexible-textured polydimethylsiloxane (PDMS) film on Cu(In,Ga)Se2 (CIGS) solar cells, which is one of the simplest and cheapest peel-off processes for fabricating a three-dimensional structure. A cell containing a textured PDMS film enhanced the short-circuit current density from 22.12 to 23.93 mA/cm2 in a simulated one-sun scenario. The omnidirectional antireflection of CIGS solar cells containing various PDMS films is also investigated. This study uses an angle-resolved reflectance spectroscope to investigate the omnidirectional and broadband optical properties of the proposed PDMS film. This improvement in light harvesting is attributable to the scattering of the PDMS film and the gradual refractive index profile between the PDMS microstructures and air. The flexible-textured PDMS film is suitable for creating an antireflective coating for a diverse range of photovoltaic devices.

  5. Entry and exit facet laser damage of optical windows with random antireflective surface structures

    Science.gov (United States)

    Sapkota, Gopal; Case, Jason R.; Potter, Matthew G.; Busse, Lynda E.; Shaw, L. Brandon; Sanghera, Jasbinder S.; Aggarwal, Ishwar D.; Poutous, Menelaos K.

    2016-12-01

    Nanosecond duration, high intensity and high average power laser pulses induce damage on uncoated optics, due to localized field enhancement at the exit surface of the components. Anti-reflection (AR) coated optics, due to their (multiple) thin film boundaries, have similar field enhancement regions, which lead to laser damage on both entry and exit sides. Nano-scale structured optical interfaces with AR performance (ARSS) have been widely demonstrated, and found to have higher laser damage resistance than conventional AR coatings. Comprehensive tests of optical entry and exit structured-surface laser damage using nanosecond pulses for ARSS are not widely available. We measured the laser damage of random anti-reflective surface structures (rARSS), on planar, optical quality, fused silica substrates, using single 6-8ns duration pulses at 1064 nm wavelength. The single-sided rARSS substrates were optimized for Fresnel reflectance suppression at 1064 nm, and the measured transmittance at normal incidence was increased by 3.2%, with a possible theoretical maximum of 3.5%. The high energy laser beam was focused to increase the incident intensity, in order to probe values above and below the damage thresholds reported in the literature. The source laser Q-switch durations were used to directly control incident fluence. Multiple locations were tested for each Q-switch setting, to build a statistical relationship between the fluence and damaging events. Single-sided, AR random surface structured substrates were tested, using entry and exit side orientations, to determine any effects the random structures may have in the damage induced by the field enhancement on the exit side. We found that the AR randomly structured surfaces have a higher resistance, to the onset of laser damage, when they are located at the entry (structured) side of the substrates. In comparison, when the same AR random structures are in the beam exit side of the substrates, the onset of laser damage

  6. Antireflective SiC Surface Fabricated by Scalable Self-Assembled Nanopatterning

    DEFF Research Database (Denmark)

    Ou, Yiyu; Fadil, Ahmed; Ou, Haiyan

    2016-01-01

    An approach for fabricating sub-wavelength antireflective structures on SiC material is demonstrated. A time-efficient scalable nanopatterning method by rapid thermal annealing of thin metal film is applied followed by a dry etching process. Size-dependent optical properties of the antireflective...

  7. Method and tool to reverse the charges in anti-reflection films used for solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Vivek; Tracy, Clarence

    2017-01-31

    A method is provided for making a solar cell. The method includes providing a stack including a substrate, a barrier layer disposed on the substrate, and an anti-reflective layer disposed on the barrier layer, where the anti-reflective layer has charge centers. The method also includes generating a corona with a charging tool and contacting the anti-reflective layer with the corona thereby injecting charge into at least some of the charge centers in the anti-reflective layer. Ultra-violet illumination and temperature-based annealing may be used to modify the charge of the anti-reflective layer.

  8. Optical coatings for metamaterials (Conference Presentation)

    Science.gov (United States)

    Jen, Yi-Jun

    2016-09-01

    Optical coatings have been referred as thin films that create interference effect to change optical properties of substrates. The most common applications of optical thin films are anti-reflection coatings, high reflective coatings, beamsplitter coatings, and bandpass filter coatings. In the recent development of metamaterials, the optical coatings also play a critical role in design, fabrication and measurement. In fabrication, glancing angle deposition has been applied to grow slanted metal nanorod arrays. The associated longitudinal plasmon and transverse plasmon modes under linear polarized illuminations are induced and generate anisotropic refractive index and extinction coefficient. Strong birefringence of a silver nanorod array reveals positive and negative real refractive indices exist for two orthogonal linear polarization states. Recently, negative index materials and hyperbolic metamaterials are realized as multilayers comprising subwavelength-scale metal and dielectric films alternatively. From the view of optical coatings, the design of optical edge filters can be applied to arrange the metal-dielectric multilayer as a symmetrical film sack to perform equivalent complex admittance and refractive index. On the other hand, the traditional admittance diagram used in design of antireflection and bandpass filters can be applied to induce the transmission of a negative index multilayer. The admittance loci of metal films are designed to be huge contours in the admittance diagram to reduce the energy loss in metal films. Five-layered symmetrical film stack and seven-layered symmetrical film stack are shown here to present as new bandpass filters with negative real refractive indices.

  9. ZnO/Al{sub 2}O{sub 3} core/shell nanorods array as excellent anti-reflection layers on silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Lung, Chun-Ming; Wang, Wei-Cheng [Department of Materials Science and Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617, Taiwan (China); Chen, Ching-Hsiang [Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, No. 43, Section 4, Keelung Road, Taipei, 106, Taiwan (China); Chen, Liang-Yih, E-mail: sampras@mail.ntust.edu.tw [Department of Chemical Engineering, National Taiwan University of Science and Technology, No. 43, Section 4, Keelung Road, Taipei, 106, Taiwan (China); Chen, Miin-Jang, E-mail: mjchen@ntu.edu.tw [Department of Materials Science and Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617, Taiwan (China)

    2016-09-01

    A simple, low-temperature hydrothermal method and atomic layer deposition (ALD) were used to fabricate ZnO nanostructures as subwavelength-structure antireflection layers (SWS ARLs) on Si solar cells. ZnO seed layers with wafer-scale uniformity were prepared, and ALD was used to reproduce two types of ZnO-based structures, nanorod arrays (NRAs) and nanotip arrays (NTAs). The study examined diammonium phosphate concentrations during growth, conducted simulations based on three-dimensional finite-difference time-domain and reflection analyses, performed X-ray diffractometer, field-emission scanning electron microscope, and high-resolution transmission electron microscope characterizations, measured total reflectance spectra by using a spectrophotometer with integrated spheres, and ran solar simulations to determine the efficiency of the Si solar cells. Coating the ZnO NTAs on the Si solar cells yielded a low total reflectance over a broad band range and produced omnidirectional light scattering on the cells, causing incident light to have a shallow penetration depth near the p–n junction and leading to an increase in short current density ({sub Jsc}). Coating the ZnO NTAs with an Al{sub 2}O{sub 3} shell induced continuous variation in the refractive index, further decreasing the total reflectance to approximately 5.5%, and protected the ZnO NTAs from the harmful acidic environment. Significantly increasing the J{sub sc} and η levels of the Si solar cells, the Al{sub 2}O{sub 3}@ZnO-NTA antireflection structure produced a high efficiency of 17.79%. Its superior performance, including low and wideband reflectance, a low process temperature, and a significant increase in efficiency, indicates the potential of this antireflective structure for enhancing solar cell efficiency in photovoltaic devices. - Highlights: • ZnO nanotip arrays were synthesized by hydrothermal methods as antireflection layer. • The total reflectance is low around 7.8% from 400 nm to 1000

  10. Use of ZnO as antireflective, protective, antibacterial, and biocompatible multifunction nanolayer of thermochromic VO{sub 2} nanofilm for intelligent windows

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Huaijuan; Li, Jinhua [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Bao, Shanhu [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Li, Jian [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Liu, Xuanyong, E-mail: xyliu@mail.sic.ac.cn [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Jin, Ping, E-mail: p-jin@mail.sic.ac.cn [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Materials Research Institute for Sustainable Development, National Institute of Advanced Industrial Science and Technology, Nagoya 463-8560 (Japan)

    2016-02-15

    Graphical abstract: - Highlights: • A multifunctional VO{sub 2}/ZnO bilayer film is designed and deposited by magnetron sputtering apparatus. • The ZnO top layer can enhance the antireflective, antioxidative and anti-corrosion functions of the VO{sub 2} film. • The ZnO top layer can endow VO{sub 2} film with excellent antibacterial performance. • The ZnO top layer can attenuate the cytotoxicity of VO{sub 2} thin film. - Abstract: A multifunctional VO{sub 2}/ZnO bilayer film is designed and deposited by magnetron sputtering apparatus. The integration of the antireflective, antioxidative and anti-corrosion functions, and antibacterial performance makes the heterostructure film a promising candidate in the energy-saving smart window. The ZnO thin film as the antireflection layer can markedly boost the solar regulation efficiency (ΔT{sub sol}) from 7.7% to 12.2% and possesses excellent luminous transmittance (T{sub lum-L} = 50.3%) in the low-temperature semiconductor phase. The ZnO layer as the protection barrier can not only protect VO{sub 2} thin film from oxidation to much toxic V{sub 2}O{sub 5}, but also decrease the release of V ions. Besides, the synergistic effect of releasing killing by Zn{sup 2+} ions and contact killing by ZnO NPs makes ZnO thin film an outstanding antibacterial coating. In terms of the biological safety, ZnO coating with appropriate film thickness can effectively attenuate the cytotoxicity of VO{sub 2} on human HIBEpiC cells. We hope this work can provide new insights for better designing of novel multifunctional VO{sub 2}-based intelligent energy-saving windows.

  11. Structure and optical properties of dielectric-metal-dielectric coatings

    Energy Technology Data Exchange (ETDEWEB)

    Koltun, M.M.; Faiziev, Sh.A.; Gaziev, U.Kh.

    1976-01-01

    The conditions for production of a ZnS-Ag-ZnS coating on glass are investigated, together with the influence of each of the three layers on the optical characteristics of the coating. It is shown that the lower antireflection film in a three-layer coating serves not only to reduce reflection from the glass-metal film interface, but also creates conditions for condensation of a metal layer with small structural defects to increase the conductivity of the coating and its integral reflection coefficient in the infrared region of the spectrum.

  12. Optimization of contaminated oxide inversion layer solar cell. [considering silicon oxide coating

    Science.gov (United States)

    Call, R. L.

    1976-01-01

    Contaminated oxide cells have been fabricated with efficiencies of 8.6% with values of I sub sc = 120 ma, V sub oc = .54 volts, and curve factor of .73. Attempts to optimize the fabrication step to yield a higher output have not been successful. The fundamental limitation is the inadequate antireflection coating afforded by the silicon dioxide coating used to hold the contaminating ions. Coatings of SiO, therefore, were used to obtain a good antireflection coating, but the thinness of the coatings prevented a large concentration of the contaminating ions, and the cells was weak. Data of the best cell were .52 volts V sub oc, 110 ma I sub sc, .66 CFF and 6.7% efficiency.

  13. Coupled-cavity-based slow light metamaterials with antireflection structures

    Science.gov (United States)

    Lee, Sun-Goo; Kim, Seong-Han; Jung, Soo-Yong; Lee, Jongjin; Park, Jong-Moon; Kee, Chul-Sik

    2016-11-01

    A slow light metamaterial based on a coupled Fabry-Pérot cavity is proposed and numerically studied using finite-difference time-domain simulations. The coupled cavity-based slow light metamaterial is composed of a periodic array of partial mirrors with low transmittance, i.e., thin metal films perforated with a subwavelength hole array. The tight-binding model is employed to investigate the transmission properties of the coupled-cavity-based metamaterial. It is shown that the group velocities of the slowly propagating modes can be controlled by adjusting the radius of holes in the mirrors. We also show that undesirable reflections at the boundaries of the finite-size metamaterial can be minimized by introducing optimized antireflection structures.

  14. Exploring anti-reflection modes in disordered media

    CERN Document Server

    Kim, Moonseok; Yoon, Changhyeong; Kim, Guang Hoon; Kim, Seung-hyun; Yi, Gi-Ra; Park, Q-Han; Choi, Wonshik

    2013-01-01

    Sensing and manipulating targets hidden under scattering media are universal problems that take place in applications ranging from deep-tissue optical imaging to laser surgery. A major issue in these applications is the shallow light penetration caused by multiple scattering that reflects most of incident light. Although advances have been made to eliminate image distortion by a scattering medium, dealing with the light reflection has remained unchallenged. Here we present a method to minimize reflected intensity by finding and coupling light into the anti-reflection modes of a scattering medium. In doing so, we achieved more than a factor of 3 increase in light penetration. Our method of controlling reflected waves makes it readily applicable to in vivo applications in which detector sensors can only be positioned at the same side of illumination and will therefore lay the foundation of advancing the working depth of many existing optical imaging and treatment technologies.

  15. A High-Transmission, Multiple Antireflective Surface Inspired from Bilayer 3D Ultrafine Hierarchical Structures in Butterfly Wing Scales.

    Science.gov (United States)

    Han, Zhiwu; Mu, Zhengzhi; Li, Bo; Niu, Shichao; Zhang, Junqiu; Ren, Luquan

    2016-02-10

    A high-transmission, multiple antireflective surface inspired by bilayer 3D ultrafine hierarchical structures in butterfly wing scales is fabricated on a glass substrate using wet chemical biomimetic fabrication. Interestingly, the biomimetic antireflective surface exhibits excellent antireflective properties and high transmission, which provides better characteristics than the butterfly wings and can significantly reduce reflection without losing transparency. These findings offer a new path for generating nanostructured antireflectors with high transmission properties.

  16. Graded index and randomly oriented core-shell silicon nanowires with broadband and wide angle antireflection for photovoltaic cell applications

    CERN Document Server

    Pignalosa, P; Qiao, L; Tseng, M; Yi, Yasha

    2011-01-01

    Antireflection with broadband and wide angle properties is important for a wide range of applications on photovoltaic cells and display. The SiOx shell layer provides a natural antireflection from air to the Si core absorption layer. In this work, we have demonstrated the random core-shell silicon nanowires with both broadband (from 400nm to 900nm) and wide angle (from normal incidence to 60\\degree) antireflection characteristics within AM1.5 solar spectrum. The graded index structure from the randomly oriented core-shell (Air/SiOx/Si) nanowires may provide a potential avenue to realize a broadband and wide angle antireflection layer.

  17. Photochromic lens mirror-coated with Cr

    Science.gov (United States)

    Shin, Sungho; Lee, Myeongkyu

    2007-11-01

    We have designed and fabricated mirror-coated photochromic lenses for use in sunglasses. These lenses consisted of a Cr thin film sandwiched between two SiO2 layers on the front surface and an anti-reflection (AR) coating on the backside. The SiO2 films above and below the Cr layer were introduced as the protection and buffer layers, respectively. The AR coating was to suppress back-reflection from the lens surface. Deposition of all coating layers were carried out by an e-beam evaporator under Ar atmosphere at P = 10-5 Torr and T = 70 °C. As expected, the overall transmittance decreased with increasing Cr thickness. For a Cr layer of 5 nm thickness, it changed from about 45% in the bleached state down to 25% after exposure to sunlight. This is consistent with the transmission range typically required for sunglasses.

  18. Removal Of Optical Coatings Without Polishing

    Science.gov (United States)

    Gourley, Helen

    1980-11-01

    A process for removing antireflection, mirror and polarizer coatings has been developed at ILC, based on work begun by LLL (Applied Optics Vol. 17, No. 12, 15 June 1978 - "Notes on Optical Coating Removal", N.J. Brown). Because of the danger (personnel hazard) involved in the hydrofluoric acid process, we employed an ammonium bifluoride solution, combined with various polishing components. The substrates, generally BK7, are fairly soft and also sensitive to chemical action. Therefore we have limited our polishing materials to aluminum oxide powder graded at 0.1 pm or smaller. For some coatings, no polishing material is used, as the ammonium bifluoride solution is adequate to remove the coating. The resulting clean surface is washed and neutralized, and is then ready for recoating.

  19. Antireflection properties and solar cell application of silicon nanoscructures

    Institute of Scientific and Technical Information of China (English)

    Yue Huihui; Jia Rui; Chen Chen; Ding Wuchang; Wu Deqi; Liu Xinyu

    2011-01-01

    Silicon nanowire arrays (SiNWAs) are fabricated on polished pyramids of textured Si using an aqueous chemical etching method.The silicon nanowires themselves or hybrid structures of nanowires and pyramids both show strong anti-reflectance abilities in the wavelength region of 300-1000 nm,and reflectances of 2.52% and less than 8% are achieved,respectively.A 12.45% SiNWAs-textured solar cell (SC) with a short circuit current of 34.82 mA/cm2 and open circuit voltage (Voc) of 594 mV was fabricated on 125 × 125 mm2 Si using a conventional process including metal grid printing.It is revealed that passivation is essential for hybrid structure textured SCs,and Voc can be enlarged by 28.6% from 420 V to 560 mV after the passivation layer is deposited.The loss mechanism of SiNWA SC was investigated in detail by systematic comparison of the basic parameters and external quantum efficiency (EQE) of samples with different fabrication processes.It is proved that surface passivation and fabrication of a metal grid are critical for high efficiency SiNWA SC,and the performance of SiNWA SC could be improved when fabricated on a substrate with an initial PN junction.

  20. Effective antireflection properties of porous silicon nanowires for photovoltaic applications

    KAUST Repository

    Najar, Adel

    2013-01-01

    Porous silicon nanowires (PSiNWs) have been prepared by metal-assisted chemical etching method on the n-Si substrate. The presence of nano-pores with pore size ranging between 10-50nm in SiNWs was confirmed by electron tomography (ET) in the transmission electron microscope (TEM). The PSiNWs give strong photoluminescence peak at red wavelength. Ultra-low reflectance of <5% span over wavelength 250 nm to 1050 nm has been measured. The finite-difference time-domain (FDTD) method has been employed to model the optical reflectance for both Si wafer and PSiNWs. Our calculation results are in agreement with the measured reflectance from nanowires length of 6 µm and 60% porosity. The low reflectance is attributed to the effective graded index of PSiNWs and enhancement of multiple optical scattering from the pores and nanowires. PSiNW structures with low surface reflectance can potentially serve as an antireflection layer for Si-based photovoltaic devices.

  1. Apparatus and method of manufacture for depositing a composite anti-reflection layer on a silicon surface

    Science.gov (United States)

    Pain, Bedabrata (Inventor)

    2012-01-01

    An apparatus and associated method are provided. A first silicon layer having at least one of an associated passivation layer and barrier is included. Also included is a composite anti-reflection layer including a stack of layers each with a different thickness and refractive index. Such composite anti-reflection layer is disposed adjacent to the first silicon layer.

  2. Preparation of Scratch-Resistant Nano-Porous Silica Films Derived by Sol-Gel Process and Their Anti-reflective Properties

    Institute of Scientific and Technical Information of China (English)

    Guangming WU; Jun SHEN; Tianhe YANG; Bin ZHOU; Jue WANG

    2003-01-01

    Structural strengthening of the nano porous silica films has been reported. The films were prepared with a base/acid two-step catalyzed TEOS-based sol-gel processing and dip-coating, and then baked in the mixed gas of ammonia and water vapor. The silica films were characterized with TEM, AFM, FTIR, spectrophotometer, ellipsometer, and abrasion test, respectively. The experimental results have shown that the films have a nanostructure with a low refractive index and can form an excellent scratch-resistant broadband anti-reflectance. The two-step catalysis noticeably strengthens the films, and the mixed gas treatment further improves mechanical strength of the silica network. Finally the strengthening mechanism has been discussed.

  3. Sol-gel synthesis of xTiO{sub 2}(100 − x)SiO{sub 2} nanocomposite thin films: Structure, optical and antireflection properties

    Energy Technology Data Exchange (ETDEWEB)

    Kermadi, S., E-mail: kermadisalim@yahoo.fr [CRTSE—Division DDCS, 02 Bd Dr. Frantz Fanon BP, 140, les 07 merveilles, 16038, Algiers (Algeria); Agoudjil, N. [Department of Chemistry, Laboratory of Physico-Chemistry of Materials and Environment, USTHB, BO Box 32 El Alia, 16111 Algiers (Algeria); Sali, S.; Boumaour, M. [CRTSE—Division DDCS, 02 Bd Dr. Frantz Fanon BP, 140, les 07 merveilles, 16038, Algiers (Algeria); Bourgeois, S.; Marco de Lucas, M.C. [Interdisciplinary Laboratory Carnot of Bourgogne, University of Bourgogne, 9 Av. A. Savary, PO Box 47 870, F-21078 Dijon (France)

    2014-08-01

    Sol-gel xTiO{sub 2}(100 − x)SiO{sub 2} nanocomposite thin films with x = 0, 25, 50, 75 and 100 mol % were dip-coated on glass and silicon substrates. The influence of the composition on structure, morphology and optical properties was studied by X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, scanning electronic microscopy, monochromatic ellipsometry at λ = 632.8 nm and ultraviolet–visible absorbance spectroscopy. The optical properties were discussed on the basis of the microstructure. After annealing at 500 °C, results showed high pure materials, homogenous crack-free surfaces with good adherence and high optical qualities. The 100% TiO{sub 2} crystallizes in the anatase phase and exhibits nanograins of 6 to 10 nm in size. However, all the other compositions are amorphous with comparable grains around 4 nm in size. The averaged transmittance decreases with increasing the TiO{sub 2} content but remains higher than 90%. Whatever the composition, the coating thickness increases linearly as the withdrawal speed increases from 10 to 54 mm/minute. The relationship between refractive index and composition was analyzed by fitting the experimental data to different theoretical models for the refractive index of mixed films. Results showed that depending on the withdrawal speed, the data can properly fit either the Drude or the linear models. Thus, the film thickness can be adjusted by the control of the withdrawal speed. However, the control of the composition allows easily the tuning of the refractive index from 1.48 to 2.18 at λ = 632.8 nm to achieve optimum anti-reflection characteristics. Different anti-reflection designs of both single and double layers were experimentally examined. Gains (assigned to the reduction of reflection losses) up to 54 and 63% were predicted with 75% TiO{sub 2} single-coating and SiO{sub 2}/TiO{sub 2} double-coatings respectively. - Highlights: • Stable sol for dip-coating xTiO{sub 2}(100 − x

  4. Silicon Nanostructures Produced by Modified MacEtch Method for Antireflective Si Surface.

    Science.gov (United States)

    Nichkalo, Stepan; Druzhinin, Anatoly; Evtukh, Anatoliy; Bratus', Oleg; Steblova, Olga

    2017-12-01

    This work pertains to the method for modification of silicon (Si) wafer morphology by metal-assisted chemical etching (MacEtch) technique suitable for fabrication of antireflective Si surfaces. For this purpose, we made different Au catalyst patterns on the surface of Si substrate. This modification allowed to obtain the close-packed Au nanodrop (ND) pattern that generates the nanowires (NWs) and the well-separated Au NDs, which induce the nanopore (NP) formation. The antireflective properties of these structures in comparison with NWs produced by the conventional Ag-MacEtch method were analysed. The total surface reflectance of 1~7% for SiNWs and ~17% for SiNPs was observed over the entire Si-absorbing region. Moreover, SiNWs prepared by Au-MacEtch demonstrate better antireflective properties in contrast to those formed by conventional Ag-assisted chemical etching. So, the use of SiNWs produced by the modified Au-MacEtch method as the antireflective material is favored over those prepared by Ag-MacEtch due to their higher light absorption and lower reflectance. The possible reason of these findings is discussed.

  5. Omnidirectional luminescence enhancement of fluorescent SiC via pseudoperiodic antireflective subwavelength structures

    DEFF Research Database (Denmark)

    Ou, Yiyu; Jokubavicius, Valdas; Yakimova, Rositza;

    2012-01-01

    In the present work, an approach of fabricating pseudoperiodic antireflective subwavelength structures (ARS) on fluorescent SiC by using self-assembled etch mask is demonstrated. By applying the pseudoperiodic (ARS), the average surface reflectance at 6° incidence over the spectral range of 390-7...

  6. Optically optimal wavelength-scale patterned ITO/ZnO composite coatings for thin film solar cells

    CERN Document Server

    Moreau, Antoine; Centeno, Emmanuel; Seassal, Christian

    2012-01-01

    A new methodology is proposed for finding structures that are, optically speaking, locally optimal : a physical analysis of much simpler structures is used to constrain the optimization process. The obtained designs are based on a flat amorphous silicon layer (to minimize recombination) with a patterned anti-reflective coating made of ITO or ZnO, or a composite ITO/ZnO coating. These latter structures are realistic and present good performances despite very thin active layers.

  7. Self-assembled nanolaminate coatings (SV)

    Energy Technology Data Exchange (ETDEWEB)

    Fan, H.

    2012-03-01

    Sandia National Laboratories (Sandia) and Lockheed Martin Aeronautics (LM Aero) are collaborating to develop affordable, self-assembled, nanocomposite coatings and associated fabrication processes that will be tailored to Lockheed Martin product requirements. The purpose of this project is to develop a family of self-assembled coatings with properties tailored to specific performance requirements, such as antireflective (AR) optics, using Sandia-developed self-assembled techniques. The project met its objectives by development of a simple and economic self-assembly processes to fabricate multifunctional coatings. Specifically, materials, functionalization methods, and associated coating processes for single layer and multiple layers coatings have been developed to accomplish high reflective coatings, hydrophobic coatings, and anti-reflective coatings. Associated modeling and simulations have been developed to guide the coating designs for optimum optical performance. The accomplishments result in significant advantages of reduced costs, increased manufacturing freedom/producibility, improved logistics, and the incorporation of new technology solutions not possible with conventional technologies. These self-assembled coatings with tailored properties will significantly address LMC's needs and give LMC a significant competitive lead in new engineered materials. This work complements SNL's LDRD and BES programs aimed at developing multifunctional nanomaterials for microelectronics and optics as well as structure/property investigations of self-assembled nanomaterials. In addition, this project will provide SNL with new opportunities to develop and apply self-assembled nanocomposite optical coatings for use in the wavelength ranges of 3-5 and 8-12 micrometers, ranges of vital importance to military-based sensors and weapons. The SANC technologies will be applied to multiple programs within the LM Company including the F-35, F-22, ADP (Future Strike Bomber

  8. Improvement and characterization of high-reflective and anti-reflective nanostructured mirrors by ion beam assisted deposition for 944 nm high power diode laser

    Science.gov (United States)

    Ghadimi-Mahani, A.; Farsad, E.; Goodarzi, A.; Tahamtan, S.; Abbasi, S. P.; Zabihi, M. S.

    2015-11-01

    Single-layer and multi-layer coatings were applied on the surface of diode laser facets as mirrors. This thin film mirrors were designed, deposited, optimized and characterized. The effects of mirrors on facet passivation and optical properties of InGaAs/AlGaAs/GaAs diode lasers were investigated. High-Reflective (HR) and Anti-Reflective (AR) mirrors comprising of four double-layers of Al2O3/Si and a single layer of Al2O3, respectively, were designed and optimized by Macleod software for 944 nm diode lasers. Optimization of Argon flow rate was studied through Alumina thin film deposition by Ion Beam Assisted Deposition (IBAD) for mirror improvement. The nanostructured HR and AR mirrors were deposited on the front and back facet of the laser respectively, by IBAD system under optimum condition. Atomic Force Microscope (AFM), Vis-IR Spectrophotometer, Field Emission Scanning Electron Microscopy (FESEM) and laser characterization Test (P-I) were used to characterize various properties of mirrors and lasers. AFM images show mirror's root mean square roughness is nearly 1 nm. The Spectrophotometer results of the front facet transmission and the back facet reflection are in good agreement with the simulation results. Optical output power (P) versus driving current (I) characteristics, measured before and after coating the facet, revealed a significant output power enhancement due to optimized AR and HR optical coatings on facets.

  9. Optical trapping of coated microspheres.

    Science.gov (United States)

    Bormuth, Volker; Jannasch, Anita; Ander, Marcel; van Kats, Carlos M; van Blaaderen, Alfons; Howard, Jonathon; Schäffer, Erik

    2008-09-01

    In an optical trap, micron-sized dielectric particles are held by a tightly focused laser beam. The optical force on the particle is composed of an attractive gradient force and a destabilizing scattering force. We hypothesized that using anti-reflection-coated microspheres would reduce scattering and lead to stronger trapping. We found that homogeneous silica and polystyrene microspheres had a sharp maximum trap stiffness at a diameter of around 800 nm--the trapping laser wavelength in water--and that a silica coating on a polystyrene microsphere was a substantial improvement for larger diameters. In addition, we noticed that homogeneous spheres of a correct size demonstrated anti-reflective properties. Our results quantitatively agreed with Mie scattering calculations and serve as a proof of principle. We used a DNA stretching experiment to confirm the large linear range in detection and force of the coated microspheres and performed a high-force motor protein assay. These measurements show that the surfaces of the coated microspheres are compatible with biophysical assays.

  10. Optical Coatings Formed by Gradient Refractive Index Materials

    Directory of Open Access Journals (Sweden)

    Kęstutis Juškevičius

    2012-01-01

    Full Text Available Recent advances in ion beam sputtering technology enabled efficient deposition of different oxide mixture coatings. In the present investigation, coating materials ZrO2 and SiO2 were utilized for the synthesis of different mixtures. The goal of the conducted investigation was to explore the potential of ZrO2/SiO2 mixtures, especially for applications in the range of the UV spectral. Deposited dielectric mirrors having classical quarter-wave and “rised” design with ZrO2/SiO2 mixture for 266 nm and 355 nm showed good resistance to laser radiation.We also investigated the “fatigue” behavior of LIDT’s in LBO crystals with single, dual and triple wavelength anti-reflective coatings (AR@355, AR@532+1064 and AR@355+532+1064 in order to optimize design and layer materials. The influence of gradient refractive index profiles on damage resistance is of a special interest. We selected a few designs of antireflective coatings which demonstrated the best resistance to laser radiation.An experimental study on rugate filter coatings showed the need for a more accurate characterization of optical properties of metal oxides and their corresponding mixtures.Article in Lithuanian

  11. Y{sub 2}O{sub 3}: Eu{sup 3+}, Tb{sup 3+} spherical particles based anti-reflection and wavelength conversion bi-functional films: Synthesis and application to solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Hui [School of Physics, Northwest University, Xi’an 710069 (China); National Photoelectric Technology and Functional Materials & Application of Science and Technology International Cooperation Base, Northwest University, Xi’an 710069 (China); Ji, Ruonan [School of Physics, Northwest University, Xi’an 710069 (China); Hu, Xiaoyun, E-mail: hxy3275@nwu.edu.cn [School of Physics, Northwest University, Xi’an 710069 (China); National Photoelectric Technology and Functional Materials & Application of Science and Technology International Cooperation Base, Northwest University, Xi’an 710069 (China); Han, Linzi; Hao, Yuanyuan; Sun, Qian [School of Physics, Northwest University, Xi’an 710069 (China); Zhang, Dekai [School of Physics, Northwest University, Xi’an 710069 (China); National Photoelectric Technology and Functional Materials & Application of Science and Technology International Cooperation Base, Northwest University, Xi’an 710069 (China); Fan, Jun [School of Chemical Engineering, Northwest University, Xi’an 710069 (China); Bai, Jintao [School of Physics, Northwest University, Xi’an 710069 (China); National Photoelectric Technology and Functional Materials & Application of Science and Technology International Cooperation Base, Northwest University, Xi’an 710069 (China); and others

    2015-04-25

    Highlights: • Eu{sup 3+} and Tb{sup 3+} co-doped Y{sub 2}O{sub 3} particles were successfully prepared. The as prepared particles can convert UV region photos to visible photons between 460 nm and 640 nm, which just matched the spectral response of most solar cells. • Y{sub 2}O{sub 3} is not only a good photoluminescence host material, but also it has high corrosion resistivity, thermal stability, and transparency from violet to infrared light. Cooperated with SiO{sub 2} sols, it could realize a better anti-reflection property. • As a proof-of-concept application, the as prepared bi-functional films could effectively improve the photoelectric conversion efficiency by 0.23% compared to pure SiO{sub 2} AR coating film and 0.55% compared to glass. - Abstract: In this study, Eu{sup 3+} and Tb{sup 3+} co-doped Y{sub 2}O{sub 3} particles were prepared via the simple, cost-effective urea homogeneous precipitation method without additives. The chosen particles were added in the SiO{sub 2} sols to get anti-reflection (AR) and wavelength conversion bi-functional films. Careful investigations were carried out to find the optimum preparation conditions and proper morphology. SEM images showed that the particle sizes reduced as metal ion/urea ratio decreased. Additionally, the extracted particles turned from sphere to lamellar type when the deionized water, which was used as solvent, reduced to a certain extent. The mechanisms of the morphology formation and diversification were proposed as well. The as prepared materials can convert UV region photos to visible photons between 460 nm and 640 nm, which just matched the spectral response of most solar cells. The spherical sample showed better luminescence performance than the one with lamellar morphology. In addition, the optical transmittance spectra indicated that the films adding spherical particles had better anti-reflective performance, and the best adding amount was 0.08 g. Finally, As a proof-of-concept application

  12. Fabrication of broadband antireflective black metal surfaces with ultra-light-trapping structures by picosecond laser texturing and chemical fluorination

    Science.gov (United States)

    Zheng, Buxiang; Wang, Wenjun; Jiang, Gedong; Mei, Xuesong

    2016-06-01

    A hybrid method consisting of ultrafast laser-assisted texturing and chemical fluorination treatment was applied for efficiently enhancing the surface broadband antireflection to fabricate black titanium alloy surface with ultra-light-trapping micro-nanostructure. Based on the theoretical analysis of surface antireflective principle of micro-nanostructures and fluoride film, the ultra-light-trapping micro-nanostructures have been processed using a picosecond pulsed ultrafast laser on titanium alloy surfaces. Then fluorination treatment has been performed by using fluoroalkyl silane solution. According to X-ray diffraction phase analysis of the surface compositions and measurement of the surface reflectance using spectrophotometer, the broadband antireflective properties of titanium alloy surface with micro-nano structural characteristics were investigated before and after fluorination treatment. The results show that the surface morphology of micro-nanostructures processed by picosecond laser has significant effects on the antireflection of light waves to reduce the surface reflectance, which can be further reduced using chemical fluorination treatment. The high antireflection of over 98 % in a broad spectral range from ultraviolet to infrared on the surface of metal material has been achieved for the surface structures, and the broadband antireflective black metal surfaces with an extremely low reflectance of ultra-light-trapping structures have been obtained in the wavelength range from ultraviolet-visible to near-infrared, middle-wave infrared. The average reflectance of microgroove groups structured surface reaches as low as 2.43 % over a broad wavelength range from 200 to 2600 nm. It indicates that the hybrid method comprising of picosecond laser texturing and chemical fluorination can effectively induce the broadband antireflective black metal surface. This method has a potential application for fabricating antireflective surface used to improve the

  13. High performance step-down AR coatings for high refractive-index IR materials.

    Science.gov (United States)

    Dobrowolski, J A; Ho, F

    1982-01-15

    A numerical thin film synthesis program has been used to design high performance antireflection coatings of the step-down type for a number of IR window materials. In the calculations, the dispersion of the optical constants of all the materials is accounted for. Various trade offs between the width of the AR region and the maximum reflection within that width are possible. For example, an AR coating for germanium has been found in which the reflectance is zinc selenide, and zinc sulfide substrates. The experimentally measured performance of several coatings will be given.

  14. Near-infrared spectroscopy for monitoring water permeability of optical coatings on plastics.

    Science.gov (United States)

    Schulz, U; Kaiser, N

    1997-02-01

    Near-infrared spectroscopy has been applied to determine the water content of plastic lenses. An analytical method is presented for monitoring the water permeability of thin layers on plastic optics by utilizing the reversible moisture absorption of organic polymers. As an example, scratch-resistant and antireflective layers on poly[diethylenglycol-bis(allylcarbonate)] lenses are investigated. The measurements demonstrate the relatively high water barrier of coatings deposited by plasma-ion-assisted deposition compared with classical physical vapor deposition coatings and polysiloxane dip coatings.

  15. Thermal Advantages for Solar Heating Systems with a Glass Cover with Antireflection Surfaces

    DEFF Research Database (Denmark)

    Furbo, Simon; Shah, Louise Jivan

    2003-01-01

    Investigations elucidate how a glass cover with antireflection surfaces can improve the efficiency of a solar collector and the thermal performance of solar heating systems. The transmittances for two glass covers for a flat-plate solar collector were measured for different incidence angles...... was determined for different solar heating systems. Three systems were investigated: solar domestic hot water systems, solar heating systems for combined space heating demand and domestic hot water supply, and large solar heating plants. The yearly thermal performance of the systems was calculated by detailed...... simulation models with collectors with a normal glass cover and with a glass cover with antireflection surfaces. The calculations were carried out for different solar fractions and temperature levels of the solar heating systems. These parameters influence greatly the thermal performance associated...

  16. Periodically Aligned Si Nanopillar Arrays as Efficient Antireflection Layers for Solar Cell Applications

    Directory of Open Access Journals (Sweden)

    Li Xiaocheng

    2010-01-01

    Full Text Available Abstract Periodically aligned Si nanopillar (PASiNP arrays were fabricated on Si substrate via a silver-catalyzed chemical etching process using the diameter-reduced polystyrene spheres as mask. The typical sub-wavelength structure of PASiNP arrays had excellent antireflection property with a low reflection loss of 2.84% for incident light within the wavelength range of 200–1,000 nm. The solar cell incorporated with the PASiNP arrays exhibited a power conversion efficiency (PCE of ~9.24% with a short circuit current density (JSC of ~29.5 mA/cm2 without using any extra surface passivation technique. The high PCE of PASiNP array-based solar cell was attributed to the excellent antireflection property of the special periodical Si nanostructure.

  17. Laser damage resistant anti-reflection microstructures for mid-infrared metal-ion doped ZnSe gain media

    Science.gov (United States)

    Hobbs, Douglas S.; MacLeod, Bruce D.; Sabatino, Ernest; Mirov, Sergey B.; Martyshkin, Dmitri V.

    2012-11-01

    Power scaling of mid-infrared laser systems based on chromium and iron doped zinc selenide (ZnSe) and zinc sulfide (ZnS) crystals is being advanced through the integration of surface relief anti-reflection microstructures (ARMs) etched directly in the facets of the laser gain media. In this study, a new ARMs texture fabrication process is demonstrated for polycrystalline ZnSe and ZnS material that results in a significant increase in pulsed laser damage resistance combined with an average reflection loss of less than 0.5% over the wavelength range of 1.9-3.0μm. The process was utilized to fabricate ARMs in chromium-doped zinc selenide (Cr2+:ZnSe) materials supplied by IPG Photonics and standardized pulsed laser induced damage threshold (LiDT) measurements at a wavelength of 2.09μm were made using the commercial testing services of Spica Technologies. It was found that the pulsed LiDT of ARMs etched in ZnSe and Cr2+:ZnSe can match or even exceed the level of a well-polished surface, a survivability that is many times higher than an equivalent performance broad-band thin-film AR coating. The results also indicate that the ARMs plasma etch process may find use as a post-polish damage mitigation technique similar to the chemical immersion used to double the damage resistance of fused silica optics. ARMs etched in Cr2+:ZnSe were also evaluated by IPG Photonics for survivability under continuous wave (CW) laser operation at a pump laser wavelength of 1.94μm. Catastrophic damage occurred between power levels of 400-500 kilowatt per square centimeter for both as polished and ARMs textured samples indicating no reduction in CW damage resistance attributable to surface effects.

  18. Both antireflection and superhydrophobicity structures achieved by direct laser interference nanomanufacturing

    Science.gov (United States)

    Wang, Dapeng; Wang, Zuobin; Zhang, Ziang; Yue, Yong; Li, Dayou; Qiu, Renxi; Maple, Carsten

    2014-06-01

    Inspired by nature, a number of techniques have been developed to fabricate the bionic structures of lotus leaves and moth eyes in order to realize the extraordinary functions of self-cleaning and antireflection. Compared with the existing technologies, we present a straightforward method to fabricate well-defined micro and nano artificial bio-structures in this work. The proposed method of direct laser interference nanomanufacturing (DLIN) takes a significant advantage of high efficiency as only a single technological procedure is needed without pretreatment, mask, and pattern transfer processes. Meanwhile, the corresponding structures show both antireflection and superhydrophobicity properties simultaneously. The developed four-beam nanosecond laser interference system configuring the TE-TE-TE-TE and TE-TE-TE-TM polarization modes was set up to generate periodic micro cone and hole structures with a huge number of nano features on the surface. The theoretical and experimental results have shown that the periodic microcone structure exhibits excellent properties with both a high contact angle (CA = 156.3°) and low omnidirectional reflectance (5.9-15.4%). Thus, DLIN is a novel and promising method suitable for mass production of self-cleaning and antireflection surface structures.

  19. UV-black rutile TiO{sub 2}: An antireflective photocatalytic nanostructure

    Energy Technology Data Exchange (ETDEWEB)

    Sanz, Ruy, E-mail: ruy.sanzgonzalez@cnr.it; Zimbone, Massimo; Buccheri, Maria Antonietta; Scuderi, Viviana; Impellizzeri, Giuliana; Privitera, Vittorio [CNR-IMM, Via Santa Sofia 64, I-95123 Catania (Italy); Romano, Lucia [Department of Physics, University of Catania, Via Santa Sofia 64, I-95123 Catania (Italy); Scuderi, Mario; Nicotra, Giuseppe [CNR-IMM, Zona industriale strada VIII n.5, I-95121 Catania (Italy); Jensen, Jens [Department of Physics, Chemistry and Biology, Linköping University, Linköping SE-581 83 (Sweden)

    2015-02-21

    This work presents an experimental study on the specific quantitative contributions of antireflective and effective surface areas on the photocatalytic and antibacterial properties of rutile TiO{sub 2} nanospikes. They are studied when continuously distributed over the whole surface and when integrated into well-defined microstructures. The nanospikes were produced following MeV ion beam irradiation of bulk rutile TiO{sub 2} single crystals and subsequent chemical etching. The ion beam irradiation generated embedded isolated crystalline nanoparticles inside an etchable amorphous TiO{sub 2} layer, and nanospikes fixed to the not etchable TiO{sub 2} bulk substrate. The produced nanospikes are shown to resist towards aggressive chemical environments and act as an efficient UV antireflective surface. The photocatalytic activity experiments were performed under the ISO 10678:2010 protocol. The photonic and quantum efficiency are reported for the studied samples. The combined micro- and nanostructured surface triples the photonic efficiency compared to the initial flat surface. Results also revealed that the antireflective effect, due to the nanostructuring, is the dominating factor compared to the increase of surface area, for the observed photocatalytic response. The obtained results may be taken as a general strategy to design and precisely evaluate photoactive nanostructures.

  20. Improved broadband and quasi-omnidirectional anti-reflection properties with biomimetic silicon nanostructures

    Science.gov (United States)

    Huang, Yi-Fan; Chattopadhyay, Surojit; Jen, Yi-Jun; Peng, Cheng-Yu; Liu, Tze-An; Hsu, Yu-Kuei; Pan, Ci-Ling; Lo, Hung-Chun; Hsu, Chih-Hsun; Chang, Yuan-Huei; Lee, Chih-Shan; Chen, Kuei-Hsien; Chen, Li-Chyong

    2007-12-01

    Nature routinely produces nanostructured surfaces with useful properties, such as the self-cleaning lotus leaf, the colour of the butterfly wing, the photoreceptor in brittlestar and the anti-reflection observed in the moth eye. Scientists and engineers have been able to mimic some of these natural structures in the laboratory and in real-world applications. Here, we report a simple aperiodic array of silicon nanotips on a 6-inch wafer with a sub-wavelength structure that can suppress the reflection of light at a range of wavelengths from the ultraviolet, through the visible part of the spectrum, to the terahertz region. Reflection is suppressed for a wide range of angles of incidence and for both s- and p-polarized light. The antireflection properties of the silicon result from changes in the refractive index caused by variations in the height of the silicon nanotips, and can be simulated with models that have been used to explain the low reflection from moth eyes. The improved anti-reflection properties of the surfaces could have applications in renewable energy and electro-optical devices for the military.

  1. Both antireflection and superhydrophobicity structures achieved by direct laser interference nanomanufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dapeng; Wang, Zuobin, E-mail: wangz@cust.edu.cn; Maple, Carsten [JR3CN and CNM, Changchun University of Science and Technology, Changchun, 130022 (China); JR3CN and IRAC, University of Bedfordshire, Luton, Bedfordshire LU1 3JU (United Kingdom); Zhang, Ziang [JR3CN and CNM, Changchun University of Science and Technology, Changchun, 130022 (China); Yue, Yong [JR3CN and CNM, Changchun University of Science and Technology, Changchun, 130022 (China); JR3CN and IRAC, University of Bedfordshire, Luton, Bedfordshire LU1 3JU (United Kingdom); DCSSE, Xi' an Jiaotong-Liverpool University, Suzhou, 215123 (China); Li, Dayou; Qiu, Renxi [JR3CN and IRAC, University of Bedfordshire, Luton, Bedfordshire LU1 3JU (United Kingdom)

    2014-06-21

    Inspired by nature, a number of techniques have been developed to fabricate the bionic structures of lotus leaves and moth eyes in order to realize the extraordinary functions of self-cleaning and antireflection. Compared with the existing technologies, we present a straightforward method to fabricate well-defined micro and nano artificial bio-structures in this work. The proposed method of direct laser interference nanomanufacturing (DLIN) takes a significant advantage of high efficiency as only a single technological procedure is needed without pretreatment, mask, and pattern transfer processes. Meanwhile, the corresponding structures show both antireflection and superhydrophobicity properties simultaneously. The developed four-beam nanosecond laser interference system configuring the TE-TE-TE-TE and TE-TE-TE-TM polarization modes was set up to generate periodic micro cone and hole structures with a huge number of nano features on the surface. The theoretical and experimental results have shown that the periodic microcone structure exhibits excellent properties with both a high contact angle (CA = 156.3°) and low omnidirectional reflectance (5.9–15.4%). Thus, DLIN is a novel and promising method suitable for mass production of self-cleaning and antireflection surface structures.

  2. Demonstration of Resonance Coupling in Scalable Dielectric Microresonator Coatings for Photovoltaics.

    Science.gov (United States)

    Ha, Dongheon; Gong, Chen; Leite, Marina S; Munday, Jeremy N

    2016-09-21

    To increase the power conversion efficiency of solar cells, improved antireflection coatings are needed to couple light into the cell with minimal parasitic loss. Here, we present measurements and simulations of an antireflection coating based on silicon dioxide (SiO2) nanospheres that improve solar cell absorption by coupling light from free space into the absorbing layer through excitation of modes within the nanospheres. The deposited monolayer of nanospheres leads to a significant increase in light absorption within an underlying semiconductor on the order of 15-20%. When the periodicity and spacing between the nanospheres are varied, whispering gallery-like modes can be excited and tuned throughout the visible spectrum. The coating was applied to a Si solar cell containing a Si3N4 antireflection layer, and an additional increase in the spectral current density of ∼5% was found. The fabrication process, involving Meyer rod rolling, is scalable and inexpensive and could enable large-scale manufacturability of microresonator-based photovoltaics.

  3. Thin film coated submicron gratings: theory, design, fabrication and application

    Energy Technology Data Exchange (ETDEWEB)

    Heine, C.

    1996-12-31

    The realization of new applications of submicron grating structures requires efficient theoretical methods and elaborate fabrication techniques. In this work rigorous diffraction theory for one-dimensional gratings has been investigated and optimization techniques, based on methods used in thin film optics, have been developed. Submicron gratings embossed in polycarbonate have been fabricated and characterized. This includes transmission measurements which are in good agreement with theoretical calculations. Designs for a wide range of optical filters, which lead to improved optical and mechanical properties, are presented. This has been demonstrated for broadband antireflection structures for solar energy applications, based on MgF{sub 2}-coated gratings. (author) figs., tabs., refs.

  4. Design and optimization of broadband wide-angle antireflection structures for binary diffractive optics.

    Science.gov (United States)

    Chang, Chih-Hao; Waller, Laura; Barbastathis, George

    2010-04-01

    We propose a class of antireflecting structures that can effectively suppress reflections for binary diffractive optics. In this structure, multiple periodic thin films with gradually varying refractive indices are used to shift all reflected diffraction to the transmitted orders. The structure is optimized to operate over broad bands and wide angles using rigorous coupled-wave analysis and genetic algorithms. We validated the structure numerically using finite-difference time-domain methods. The proposed structure may lead to more efficient diffractive devices for applications in thin-film photovoltaic, waveguide coupler, and holographic optical elements.

  5. Absorbing Backside Anti-reflecting Layers for high contrast imaging in fluid cells

    CERN Document Server

    Ausserré, Dominique; Amra, Claude; Zerrad, Myriam

    2014-01-01

    The single Anti-Reflecting (AR) layer is a classical problem in optics. When all materials are pure dielectrics, the solution is the so-called lambda/4 layer. Here we examine the case of absorbing layers between non absorbing media. We find a solution for any layer absorption coefficient provided that the light goes from the higher towards the lower index medium, which characterizes backside layers. We describe these AR absorbing (ARA) layers through generalized index and thickness conditions. They are most often ultrathin, and have important applications for high contrast imaging in fluid cells.

  6. Broadband antireflective silicon carbide surface produced by cost-effective method

    DEFF Research Database (Denmark)

    Argyraki, Aikaterini; Ou, Yiyu; Ou, Haiyan

    2013-01-01

    A cost-effective method for fabricating antireflective subwavelength structures on silicon carbide is demonstrated. The nanopatterning is performed in a 2-step process: aluminum deposition and reactive ion etching. The effect, of the deposited aluminum film thickness and the reactive ion etching...... conditions, on the average surface reflectance and nanostructure landscape have been investigated systematically. The average reflectance of silicon carbide surface is significantly suppressed from 25.4% to 0.05%, under the optimal experimental conditions, in the wavelength range of 390-784 nm. The presence...... of stochastic nanostructures also changes the wetting properties of silicon carbide surface from hydrophilic (47°) to hydrophobic (108°)....

  7. Realization of effective light trapping and omnidirectional antireflection in smooth surface silicon nanowire arrays.

    Science.gov (United States)

    Xie, W Q; Oh, J I; Shen, W Z

    2011-02-11

    We have successfully fabricated well-ordered silicon nanowire (SiNW) arrays of smooth surface by using a low-cost and facile Ag-assisted chemical etching technique. We have experimentally found that the reflectance can be significantly suppressed (absorption in SiNW arrays, we have obtained a photocurrent enhancement of up to 425% per unit volume of material as compared to crystalline Si, implying that effective light trapping can be realized in the as-grown samples. In addition, we have demonstrated experimentally and theoretically that the as-grown samples have an omnidirectional high-efficiency antireflection property.

  8. Novel detection and process improvement for organic coating-film defects

    Science.gov (United States)

    Harumoto, Masahiko; Tanaka, Yuji; Hisai, Akihiro; Asai, Masaya; Ota, Hideo; Endo, Fumiaki; Takahashi, Kazuo

    2016-03-01

    Spin coating has been used as a photoresist application method for many years,[1,2] and it has continued to include applications such as the tri-layer with stacked photoresist, Si containing anti-reflected coating (Si-ARC), and Spin on Carbon (SOC). Last year we reported EUV defectivity improvement, but the causes of some defect types were not found.[3,4] In this study, the defects unique to the coated organic film were detected using an LS9300 by Hitachi High-Technologies, and some of these defects were able to be mitigated by optimizing the SOKUDO-DUO track system. Utilizing these systems in tandem, we have revealed a mechanism of EUV pattern defect reduction linked to novel detected film coating defects. During the conference, we will discuss expansion of this concept to other film coatings.

  9. 3D-Printed Broadband Dielectric Tube Terahertz Waveguide with Anti-Reflection Structure

    Science.gov (United States)

    Vogt, Dominik Walter; Leonhardt, Rainer

    2016-11-01

    We demonstrate broadband, low loss, and close-to-zero dispersion guidance of terahertz (THz) radiation in a dielectric tube with an anti-reflection structure (AR-tube waveguide) in the frequency range from 0.2 to 1.0 THz. The anti-reflection structure (ARS) consists of close-packed cones in a hexagonal lattice arranged on the outer surface of the tube cladding. The feature size of the ARS is in the order of the wavelength between 0.2 and 1.0 THz. The waveguides are fabricated with the versatile and cost efficient 3D-printing method. Terahertz time-domain spectroscopy (THz-TDS) measurements as well as 3D finite-difference time-domain simulations (FDTD) are performed to extensively characterize the AR-tube waveguides. Spectrograms, attenuation spectra, effective phase refractive indices, and the group-velocity dispersion parameters β 2 of the AR-tube waveguides are presented. Both the experimental and numerical results confirm the extended bandwidth and smaller group-velocity dispersion of the AR-tube waveguide compared to a low loss plain dielectric tube THz waveguide. The AR-tube waveguide prototypes show an attenuation spectrum close to the theoretical limit given by the infinite cladding tube waveguide.

  10. 3D-Printed Broadband Dielectric Tube Terahertz Waveguide with Anti-Reflection Structure

    Science.gov (United States)

    Vogt, Dominik Walter; Leonhardt, Rainer

    2016-07-01

    We demonstrate broadband, low loss, and close-to-zero dispersion guidance of terahertz (THz) radiation in a dielectric tube with an anti-reflection structure (AR-tube waveguide) in the frequency range from 0.2 to 1.0 THz. The anti-reflection structure (ARS) consists of close-packed cones in a hexagonal lattice arranged on the outer surface of the tube cladding. The feature size of the ARS is in the order of the wavelength between 0.2 and 1.0 THz. The waveguides are fabricated with the versatile and cost efficient 3D-printing method. Terahertz time-domain spectroscopy (THz-TDS) measurements as well as 3D finite-difference time-domain simulations (FDTD) are performed to extensively characterize the AR-tube waveguides. Spectrograms, attenuation spectra, effective phase refractive indices, and the group-velocity dispersion parameters β 2 of the AR-tube waveguides are presented. Both the experimental and numerical results confirm the extended bandwidth and smaller group-velocity dispersion of the AR-tube waveguide compared to a low loss plain dielectric tube THz waveguide. The AR-tube waveguide prototypes show an attenuation spectrum close to the theoretical limit given by the infinite cladding tube waveguide.

  11. Excellent Passivation and Low Reflectivity Al2O3/TiO2 Bilayer Coatings for n-Wafer Silicon Solar Cells: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Lee, B. G.; Skarp, J.; Malinen, V.; Li, S.; Choi, S.; Branz, H. M.

    2012-06-01

    A bilayer coating of Al2O3 and TiO2 is used to simultaneously achieve excellent passivation and low reflectivity on p-type silicon. This coating is targeted for achieving high efficiency n-wafer Si solar cells, where both passivation and anti-reflection (AR) are needed at the front-side p-type emitter. It could also be valuable for front-side passivation and AR of rear-emitter and interdigitated back contact p-wafer cells. We achieve high minority carrier lifetimes {approx}1 ms, as well as a nearly 2% decrease in absolute reflectivity, as compared to a standard silicon nitride AR coating.

  12. Antireflective downconversion ZnO:Er3+,Yb3+ thin film for Si solar cell applications

    Science.gov (United States)

    Elleuch, R.; Salhi, R.; Deschanvres, J.-L.; Maalej, R.

    2015-02-01

    Hexagonal wurtzite phased ZnO:Er3+/Yb3+ thin films with various Yb concentrations were deposited on Si(111) substrate by Aerosol Assisted Chemical Vapor Deposition process. Post-annealed films at 1000 °C in air atmosphere showed a crystallinity enhancement. Yb3+ (4F7/2 → 4F5/2) 1000 nm emission increased with the increase of Yb3+ concentration emanating from an Er-Yb energy transfer. The reflectance percentage of 12% was achieved in the [250-1000 nm] range, and the refractive index of 1.97 was obtained for 632 nm wavelength. These results suggest that the (3 mol. % Er, 9 mol. % Yb) codoped film is a highly efficient antireflective downconversion layer for enhancing Si solar cell efficiency.

  13. Forming high efficiency silicon solar cells using density-graded anti-reflection surfaces

    Science.gov (United States)

    Yuan, Hao-Chih; Branz, Howard M.; Page, Matthew R.

    2014-09-09

    A method (50) is provided for processing a graded-density AR silicon surface (14) to provide effective surface passivation. The method (50) includes positioning a substrate or wafer (12) with a silicon surface (14) in a reaction or processing chamber (42). The silicon surface (14) has been processed (52) to be an AR surface with a density gradient or region of black silicon. The method (50) continues with heating (54) the chamber (42) to a high temperature for both doping and surface passivation. The method (50) includes forming (58), with a dopant-containing precursor in contact with the silicon surface (14) of the substrate (12), an emitter junction (16) proximate to the silicon surface (14) by doping the substrate (12). The method (50) further includes, while the chamber is maintained at the high or raised temperature, forming (62) a passivation layer (19) on the graded-density silicon anti-reflection surface (14).

  14. Efficient antireflective downconversion Er{sup 3+} doped ZnO/Si thin film

    Energy Technology Data Exchange (ETDEWEB)

    Elleuch, R. [Laboratoire Géoressouces, Matériaux, Environnement et Changements Globaux, Faculté des Sciences de Sfax, Université de Sfax, 3018 Sfax (Tunisia); Salhi, R. [Laboratoire de Chimie Industrielle, École Nationale d' Ingénieur de Sfax, Université de Sfax, 3038 Sfax (Tunisia); Al-Quraishi, S.I. [King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Deschanvres, J.-L. [Laboratoire des Matériaux et du Génie Physique, 3 Parvis Louis Néel, BP 257, 38016 Grenoble (France); Maâlej, R., E-mail: ramzi.maalej@fss.rnu.tn [Laboratoire Géoressouces, Matériaux, Environnement et Changements Globaux, Faculté des Sciences de Sfax, Université de Sfax, 3018 Sfax (Tunisia)

    2014-05-01

    This study is an investigation of the potential of Er doped ZnO thin films for downconversion photons and an antireflective layer when placed in front of the silicon solar cells. We optimized the properties of the film with appropriate deposition conditions on Si (111) substrate by aerosol assisted chemical vapor deposition (AACVD) process. An enhancement of both crystallinity and optical response was achieved in the case of film doped with 2.504 at.% Er{sup 3+}. A low reflectance and high refractive index of the film were obtained at around 632 nm. Downconversion process was also reached for this film under visible excitation to near-infrared (NIR) 980 nm photons useful for Si solar cell.

  15. Broadband antireflection silicon carbide surface by self-assembled nanopatterned reactive-ion etching

    DEFF Research Database (Denmark)

    Ou, Yiyu; Aijaz, Imran; Jokubavicius, Valdas;

    2013-01-01

    An approach of fabricating pseudoperiodic antireflective subwavelength structures on silicon carbide by using self-assembled Au nanopatterns as etching mask is demonstrated. The nanopatterning process is more time-efficiency than the e-beam lithography or nanoimprint lithography process....... The influences of the reactive-ion etching conditions and deposited Au film thickness to the subwavelength structure profile and its corresponding surface reflectance have been systematically investigated. Under the optimal experimental conditions, the average reflectance of the silicon carbide in the range...... of 390x02013;784 nm is dramatically suppressed from 21.0x00025; to 1.9x00025; after introducing the pseudoperiodic nanostructures. A luminescence enhancement of 226x00025; was achieved at an emission angle of 20x000B0; on the fluorescent silicon carbide. Meanwhile, the angle-resolved photoluminescence...

  16. An antireflection transparent conductor with ultralow optical loss (<2 %) and electrical resistance (<6 Ω sq-1)

    Science.gov (United States)

    Maniyara, Rinu Abraham; Mkhitaryan, Vahagn K.; Chen, Tong Lai; Ghosh, Dhriti Sundar; Pruneri, Valerio

    2016-12-01

    Transparent conductors are essential in many optoelectronic devices, such as displays, smart windows, light-emitting diodes and solar cells. Here we demonstrate a transparent conductor with optical loss of ~1.6%, that is, even lower than that of single-layer graphene (2.3%), and transmission higher than 98% over the visible wavelength range. This was possible by an optimized antireflection design consisting in applying Al-doped ZnO and TiO2 layers with precise thicknesses to a highly conductive Ag ultrathin film. The proposed multilayer structure also possesses a low electrical resistance (5.75 Ω sq-1), a figure of merit four times larger than that of indium tin oxide, the most widely used transparent conductor today, and, contrary to it, is mechanically flexible and room temperature deposited. To assess the application potentials, transparent shielding of radiofrequency and microwave interference signals with ~30 dB attenuation up to 18 GHz was achieved.

  17. Side by side tests of two SDHW systems with solar collectors with and without antireflection treatment

    DEFF Research Database (Denmark)

    Kong, Weiqiang; Han, Jiangong; Perers, Bengt

    2015-01-01

    Two low flow SDHW systems based on mantle tanks are tested side by side in a laboratory test facility for solar heating systems under the same weather and operation conditions. The systems are identical with the exception that one system is equipped with a solar collector with antireflection...... treated glass while the other system has a collector with a normal glass. Measurements of the thermal performance of the two systems have been carried out for a long measuring period. The thermal performances of the systems have also been calculated with a detailed simulation model. There is a good...... agreement between measured and calculated thermal performances for both systems. The extra thermal performance of the system with the solar collector with the anti reflection treated glass cover is a strong function of the solar fraction. In sunny periods with high solar fractions the percentage extra...

  18. High quality antireflective ZnS thin films prepared by chemical bath deposition

    Energy Technology Data Exchange (ETDEWEB)

    Tec-Yam, S.; Rojas, J.; Rejon, V. [Centro de Investigacion y de Estudios Avanzados del IPN, Unidad Merida, Departamento de Fisica Aplicada, Km. 6 Antigua Carretera a Progreso, AP 73-Cordemex, 97310 Merida Yucatan (Mexico); Oliva, A.I., E-mail: oliva@mda.cinvestav.mx [Centro de Investigacion y de Estudios Avanzados del IPN, Unidad Merida, Departamento de Fisica Aplicada, Km. 6 Antigua Carretera a Progreso, AP 73-Cordemex, 97310 Merida Yucatan (Mexico)

    2012-10-15

    Zinc sulfide (ZnS) thin films for antireflective applications were deposited on glass substrates by chemical bath deposition (CBD). Chemical analysis of the soluble species permits to predict the optimal pH conditions to obtain high quality ZnS films. For the CBD, the ZnCl{sub 2}, NH{sub 4}NO{sub 3}, and CS(NH{sub 2}){sub 2} were fixed components, whereas the KOH concentration was varied from 0.8 to 1.4 M. Groups of samples with deposition times from 60 to 120 min were prepared in a bath with magnetic agitation and heated at 90 Degree-Sign C. ZnS films obtained from optimal KOH concentrations of 0.9 M and 1.0 M exhibited high transparency, homogeneity, adherence, and crystalline. The ZnS films presented a band gap energy of 3.84 eV, an atomic Zn:S stoichiometry ratio of 49:51, a transmittance above 85% in the 300-800 nm wavelength range, and a reflectance below 25% in the UV-Vis range. X-ray diffraction analysis revealed a cubic structure in the (111) orientation for the films. The thickness of the films was tuned between 60 nm and 135 nm by controlling the deposition time and KOH concentration. The incorporation of the CBD-ZnS films into ITO/ZnS/CdS/CdTe and glass/Mo/ZnS heterostructures as antireflective layer confirms their high optical quality. -- Highlights: Black-Right-Pointing-Pointer High quality ZnS thin films were prepared by chemical bath deposition (CBD). Black-Right-Pointing-Pointer Better CBD-ZnS films were achieved by using 0.9 M-KOH concentration. Black-Right-Pointing-Pointer Reduction in the reflectance was obtained for ZnS films used as buffer layers.

  19. Development of a Multi-layer Anti-reflective Coating for Gallium Arsenide/Aluminum Gallium Arsenide Solar Cells

    Science.gov (United States)

    2015-07-01

    of light into power is more efficient than silicon. This gives GaAs solar cells the advantage in low-light conditions. Further, with their multi...of the solar cell actually end up in the active region able to convert photon energy into electrical energy . Several mechanisms contribute to energy ...and therefore, generate more photocurrent in the solar cell. As the photon having energy equal to or greater than the bandgap travels into the

  20. Characterisation and optimisation of PECVD SiNx as an antireflection coating and passivation layer for silicon solar cells

    Directory of Open Access Journals (Sweden)

    Yimao Wan

    2013-03-01

    Full Text Available In this work, we investigate how the film properties of silicon nitride (SiNx depend on its deposition conditions when formed by plasma enhanced chemical vapour deposition (PECVD. The examination is conducted with a Roth & Rau AK400 PECVD reactor, where the varied parameters are deposition temperature, pressure, gas flow ratio, total gas flow, microwave plasma power and radio-frequency bias voltage. The films are evaluated by Fourier transform infrared spectroscopy to determine structural properties, by spectrophotometry to determine optical properties, and by capacitance–voltage and photoconductance measurements to determine electronic properties. After reporting on the dependence of SiNx properties on deposition parameters, we determine the optimized deposition conditions that attain low absorption and low recombination. On the basis of SiNx growth models proposed in the literature and of our experimental results, we discuss how each process parameter affects the deposition rate and chemical bond density. We then focus on the effective surface recombination velocity Seff, which is of primary importance to solar cells. We find that for the SiNx prepared in this work, 1 Seff does not correlate universally with the bulk structural and optical properties such as chemical bond densities and refractive index, and 2 Seff depends primarily on the defect density at the SiNx-Si interface rather than the insulator charge. Finally, employing the optimized deposition condition, we achieve a relatively constant and low Seff,UL on low-resistivity (≤1.1 Ωcm p- and n-type c-Si substrates over a broad range of n = 1.85–4.07. The results of this study demonstrate that the trade-off between optical transmission and surface passivation can be circumvented. Although we focus on photovoltaic applications, this study may be useful for any device for which it is desirable to maximize light transmission and surface passivation.

  1. Long term testing and evaluation of PV modules with and without Sunarc antireflective coating of the cover glass

    DEFF Research Database (Denmark)

    Perers, Bengt; Furbo, Simon; Han, Jiangong;

    2015-01-01

    that also realized the MPP tracking to give the maximum output of each module. The electric power output was measured both on the AC and DC side and with different measurement equipment to be sure about the accuracy in improvement. The results indicate a potential long term improvement in a system from 3......% up to 6%. The improvement is best in facade and off south tilted orientations, where the better incidence angle modifier, has a larger influence. In the PV application only one side of the glass treatment is active. This reduces the possible improvement compared to solar thermal and greenhouse...

  2. Silicon nitride and intrinsic amorphous silicon double antireflection coatings for thin-film solar cells on foreign substrates

    Energy Technology Data Exchange (ETDEWEB)

    Li, Da; Kunz, Thomas [Bavarian Center for Applied Energy Research (ZAE Bayern), Division: Photovoltaics and Thermosensoric, Haberstr. 2a, 91058 Erlangen (Germany); Wolf, Nadine [Bavarian Center for Applied Energy Research (ZAE Bayern), Division: Energy Efficiency, Am Galgenberg 87, 97074 Wuerzburg (Germany); Liebig, Jan Philipp [Materials Science and Engineering, Institute I, University of Erlangen-Nuremberg, Martensstr. 5, 91058 Erlangen (Germany); Wittmann, Stephan; Ahmad, Taimoor; Hessmann, Maik T.; Auer, Richard [Bavarian Center for Applied Energy Research (ZAE Bayern), Division: Photovoltaics and Thermosensoric, Haberstr. 2a, 91058 Erlangen (Germany); Göken, Mathias [Materials Science and Engineering, Institute I, University of Erlangen-Nuremberg, Martensstr. 5, 91058 Erlangen (Germany); Brabec, Christoph J. [Bavarian Center for Applied Energy Research (ZAE Bayern), Division: Photovoltaics and Thermosensoric, Haberstr. 2a, 91058 Erlangen (Germany); Institute of Materials for Electronics and Energy Technology, University of Erlangen-Nuremberg, Martensstr. 7, 91058 Erlangen (Germany)

    2015-05-29

    Hydrogenated intrinsic amorphous silicon (a-Si:H) was investigated as a surface passivation method for crystalline silicon thin film solar cells on graphite substrates. The results of the experiments, including quantum efficiency and current density-voltage measurements, show improvements in cell performance. This improvement is due to surface passivation by an a-Si:H(i) layer, which increases the open circuit voltage and the fill factor. In comparison with our previous work, we have achieved an increase of 0.6% absolute cell efficiency for a 40 μm thick 4 cm{sup 2} aperture area on the graphite substrate. The optical properties of the SiN{sub x}/a-Si:H(i) stack were studied using spectroscopic ellipsometer techniques. Scanning transmission electron microscopy inside a scanning electron microscope was applied to characterize the cross section of the SiN{sub x}/a-Si:H(i) stack using focus ion beam preparation. - Highlights: • We report a 10.8% efficiency for thin-film silicon solar cell on graphite. • Hydrogenated intrinsic amorphous silicon was applied for surface passivation. • SiN{sub x}/a-Si:H(i) stacks were characterized by spectroscopic ellipsometer techniques. • Cross-section micrograph was obtained by scanning transmission electron microscopy. • Quantum efficiency and J-V measurements show improvements in the cell performance.

  3. Design of functional hybrid coatings with anti-biofouling, self-cleaning and anti-reflecting applications

    OpenAIRE

    Santiago Sánchez, Alexander

    2016-01-01

    263 p. Los recubrimientos son aplicados sobre diferentes superficies con fines fundamentalmente decorativos y de protección. Sin embargo, hoy en día el mercado de estos materiales está siendo sometido a unas especificaciones cada vez más severas. Así, los recubrimientos actuales deben, además de ser decorativos y protectores del sustrato, impartir al mismo otras propiedades adicionales como por ejemplo baja adherencia a los microorganismos, facilidad de limpieza y propiedades auto-reparabl...

  4. Anti- reflective device having an anti-reflection surface formed of silicon spikes with nano-tips

    Science.gov (United States)

    Bae, Youngsman (Inventor); Mooasser, Sohrab (Inventor); Manohara, Harish (Inventor); Lee, Choonsup (Inventor); Bae, Kungsam (Inventor)

    2009-01-01

    Described is a device having an anti-reflection surface. The device comprises a silicon substrate with a plurality of silicon spikes formed on the substrate. A first metallic layer is formed on the silicon spikes to form the anti-reflection surface. The device further includes an aperture that extends through the substrate. A second metallic layer is formed on the substrate. The second metallic layer includes a hole that is aligned with the aperture. A spacer is attached with the silicon substrate to provide a gap between an attached sensor apparatus. Therefore, operating as a Micro-sun sensor, light entering the hole passes through the aperture to be sensed by the sensor apparatus. Additionally, light reflected by the sensor apparatus toward the first side of the silicon substrate is absorbed by the first metallic layer and silicon spikes and is thereby prevented from being reflected back toward the sensor apparatus.

  5. Multispectral Coatings

    Science.gov (United States)

    2010-01-01

    nanowires. 2.2 Project Objectives  This project used spin coating technology, new and commercial nanoparticle composites, and ODC’s patented...of this project. The spin coating method to deposit polymers has been widely studied and allows for simple, low cost depositions of thin films...Figure 5). Spin coating controls the layer thickness by balancing the centrifugal forces of a developing thin film to the viscous forces that increase

  6. Low-cost, flexible, and self-cleaning 3D nanocone anti-reflection films for high-efficiency photovoltaics.

    Science.gov (United States)

    Tsui, Kwong-Hoi; Lin, Qingfeng; Chou, Hungtao; Zhang, Qianpeng; Fu, Huiying; Qi, Pengfei; Fan, Zhiyong

    2014-05-01

    Low-cost engineered nanotemplates are used to mold flexible nanocone anti-reflection (AR) films. Both optical reflectance measurements and photovoltaics characterizations demonstrate that the flexible nanocone AR films can considerably suppress device front-side reflectance and thus improve the power conversion efficiency of high-efficiency thin-film CdTe solar cells. Additionally, these nanocone AR films are found to be superhydrophobic and thus possess self-cleaning capability.

  7. Lithography-Free, Low-Cost Method for Improving Photodiode Performance by Etching Silicon Nanocones as Antireflection Layer

    CERN Document Server

    Jiang, Jing; Lin, Jiahao; Liu, Gang Logan

    2016-01-01

    A three-step process has been demonstrated to improve the performance of photodiode by creating nanocone forest on the surface of photodiode as an antireflection layer. This high-throughput, low-cost process has been shown to decrease the reflectivity by 66.1%, enhance the quantum efficiency by 27%, and increase the responsivity by 25.7%. This low-cost manufacture process can be applied to increase the responsivity of silicon based photonic devices.

  8. Morbus Coats

    Science.gov (United States)

    Förl, B.; Schmack, I.; Grossniklaus, H.E.; Rohrschneider, K.

    2010-01-01

    Der fortgeschrittene Morbus Coats stellt im Kleinkindalter eine der schwierigsten Differenzialdiagnosen zum Retinoblastom dar. Wir beschreiben die klinischen und histologischen Befunde zweier Jungen im Alter von 9 und 21 Monaten mit einseitiger Leukokorie. Trotz umfassender Diagnostik mittels Narkoseuntersuchung, MRT und Ultraschall konnte ein Retinoblastom nicht sicher ausgeschlossen werden, und es erfolgte eine Enukleation. Histologisch wurde die Diagnose eines Morbus Coats gesichert. Da eine differenzialdiagnostische Abgrenzung zwischen Morbus Coats und Retinoblastom schwierig sein kann, halten wir in zweifelhaften Fällen auch angesichts der eingeschränkten Visusprognose und potenzieller Sekundärkomplikationen beim fortgeschrittenen Morbus Coats eine Enukleation für indiziert. PMID:18299842

  9. Influence of window layer thickness on double layer antirefiection coating for triple junction solar cells*

    Institute of Scientific and Technical Information of China (English)

    Wang Lijuan; Zhan Feng; Yu Ying; Zhu Yan; Liu Shaoqing; Huang Shesong; Ni Haiqiao; Niu Zhichuan

    2011-01-01

    The optimization of a SiO2/TiO2, SiO2/ZnS double layer antireflection coating (ARC) on Ga0.5ln0.5P/ln0.02Ga0.98As/Ge solar cells for terrestrial application is discussed. The Al0.5In0.5P window layer thickness is also taken into consideration. It is shown that the optimal parameters of double layer ARC vary with the thickness of the window layer.

  10. Towards perfect light coupling and absorption in nanomembranes with omni-directional anti-reflection and photonic crystal structures

    Science.gov (United States)

    Chadha, Arvinder Singh

    investigated in detail. The front-surface Fresnel reflection is reduced with the incorporation of an omni-directional anti-reflection coating (Omni-ARC) based on nanostructures or by deposition of graded refractive index (GRIN) films. A design methodology based on the comparison of the rate of change of the refractive index profile of nanostructures of different shapes and thickness as an equivalent GRIN film suggests the minimum feature size needed to give near perfect ARC. Numerical models were built to account for the non - uniform GRIN film deposition on both rigid and flexible, flat and curved surfaces resulting from the variation in the resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) process technology. With the miniaturization of the devices, the effect of finite beam size and finite active area of the photonic components on the optical properties like transmission, reflection and scattering loss was studied as well. All the numerical studies presented in the thesis are validated by experimental results.

  11. Random Si nanopillars for broadband antireflection in crystalline silicon solar cells

    Science.gov (United States)

    Choi, Junhee; Lee, Taek Sung; Jeong, Doo Seok; Lee, Wook Seong; Kim, Won Mok; Lee, Kyeong-Seok; Kim, Donghwan; Kim, Inho

    2016-09-01

    We demonstrate the fabrication of shallow Si nanopillar structures at a submicron scale which provides broadband antireflection for crystalline Si (c-Si) solar cells in the wavelength range of 350 nm-1100 nm. The Si random nanopillars were made by reactive ion etch (RIE) processing with thermally dewetted Sn metals as an etch mask. The diameters and coverages of the Si nanopillars were adjusted in a wide range of the nanoscale to microscale by varying the nominal thickness of the Sn metals and subsequent annealing temperatures. The height of the nanopillars was controlled by the RIE process time. The optimal size of the nanopillars, which are 340 nm in diameter and 150 nm in height, leads to the lowest average reflectance of 3.6%. We showed that the power conversion efficiency of the c-Si solar cells could be enhanced with the incorporation of optimally designed Si random nanopillars from 13.3% to 14.0%. The fabrication scheme of the Si nanostructures we propose in this study would be a cost-effective and promising light trapping technique for efficient c-Si solar cells.

  12. An optimization algorithm for designing robust and simple antireflection films for organic photovoltaic cells

    Science.gov (United States)

    Kubota, S.; Kanomata, K.; Momiyama, K.; Suzuki, T.; Hirose, F.

    2013-10-01

    We propose an optimization algorithm to design multilayer antireflection (AR) structure, which has robustness against variations in layer thicknesses, for organic photovoltaic cells. When a set of available materials are given, the proposed method searches for the material and thickness of each AR layer to maximize the short-circuit current density (Jsc). This algorithm allows for obtaining a set of solutions, including optimal and quasi-optimal solutions, at the same time, so that we can clearly make comparison between them. In addition, the effects of deviations in the thicknesses of the AR layers are examined for the (quasi-)optimal solutions obtained. The expectation of the decrease in the AR performance is estimated by calculating the changes in Jsc when the thicknesses of all AR layers are varied independently. We show that some of quasi-optimal solutions may have simpler layer configuration and can be more robust against the deviations in film thicknesses, than the optimal solution. This method indicates the importance of actively searching valuable, nonoptimal solutions for practical design of AR films. We also discuss the optical conditions that lead to light absorption in the back metal contact and the effects of changing active layer thicknesses.

  13. Antireflection silicon structures with hydrophobic property fabricated by three-beam laser interference

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, L. [CNM and JR3CN (Changchun University of Science and Technology), Changchun 130022 (China); JR3CN (University of Bedfordshire), Luton LU1 3JU (United Kingdom); Wang, Z., E-mail: wangz@cust.edu.cn [CNM and JR3CN (Changchun University of Science and Technology), Changchun 130022 (China); JR3CN (University of Bedfordshire), Luton LU1 3JU (United Kingdom); Zhang, J.; Cao, L.; Li, L. [CNM and JR3CN (Changchun University of Science and Technology), Changchun 130022 (China); Yue, Y. [CNM and JR3CN (Changchun University of Science and Technology), Changchun 130022 (China); JR3CN (University of Bedfordshire), Luton LU1 3JU (United Kingdom); Xi’an Jiaotong-Liverpool University, Suzhou 215000 (China); Li, D. [CNM and JR3CN (Changchun University of Science and Technology), Changchun 130022 (China); JR3CN (University of Bedfordshire), Luton LU1 3JU (United Kingdom)

    2015-08-15

    Highlights: • A three-beam laser interference system was set up to generate periodic structures. • Silicon surfaces were directly modified by nanosecond laser interference. • The hexagonally-distributed hole structures can have considerably low reflectance. • The resulting structures have a large contact angle and self-cleaning capability. • The modulation phenomenon is not evident in three-beam laser interference. - Abstract: This paper demonstrates antireflective structures on silicon wafer surfaces with hydrophobic property fabricated by three-beam laser interference. In this work, a three-beam laser interference system was set up to generate periodic micro–nano hole structures with hexagonal distributions. Compared with the existing technologies, the array of hexagonally-distributed hole structures fabricated by three-beam laser interference reveals a design guideline to achieve considerably low solar-weighted reflectance (SWR) in the wavelength range of 300–780 nm. The resulting periodic hexagonally-distributed hole structures have shown extremely low SWR (1.86%) and relatively large contact angle (140°) providing with a self-cleaning capability on the solar cell surface.

  14. Large-area, size-tunable Si nanopillar arrays with enhanced antireflective and plasmonic properties.

    Science.gov (United States)

    Niu, Lihong; Jiang, Xiaohong; Zhao, Yaolong; Ma, Haiguang; Yang, Jingjing; Cheng, Ke; Du, Zuliang

    2016-08-01

    In this paper, a novel method using the modified Langmuir-Blodgett and float-transfer techniques was introduced to construct the perfect PS monolayer nanosphere template with large area up to cm(2). Based on such templates, the diameter, length, packing density, and the shape of Si nanopillar arrays (Si NPAs) could be precisely controlled and tuned through the modified nanosphere lithography combined with a metal-assisted chemical etching (NSL-MACE) method. Manipulation of the etching time can effectively avoid permanent deformation/clumping to generate size-tunable Si NPAs. The optical properties of the Si NPAs can be controlled by the Si NPA morphologies resulting from the different reactive ion etching (RIE) time and chemical etching time. The enhanced antireflective property and electromagnetic field effect of Au/Si NPAs were proved by the results. The new modified NSL-MACE technique with the capability of scale-up fabrication of Si NPAs would be helpful for potential applications in optoelectronic devices.

  15. High Performance Laser Amplifiers at 1.5 μm using E-Gum Evaporated Hafnium Di-Oxide Coatings

    Science.gov (United States)

    Tiemeijer, L. F.; Kuindersma, P. I.; Krekels, H. C. J.; Es-Spiekman, W. v.; Hendrix, L. J. M.; Ludwig, R.; Küller, L.

    1990-02-01

    E-gun evaporated Hafnium di-Oxide anti-reflective coatings are shown to be an attractive alternative for sputtered Silicon Oxide AR coatings. Laser amplifiers were fabricated using this material and a modal reflectivity as low as 1.7× 10-4 was obtained. A single pass gain of 26 dB together with a ripple as low as 2 dB for the TE mode were measured. Furthermore a 3 dB output saturation power of {+}8 dBm and a fiber coupling loss of 3.5 dB/facet were measured.

  16. Broadband Antireflection and Light Extraction Enhancement in Fluorescent SiC with Nanodome Structures

    DEFF Research Database (Denmark)

    Ou, Yiyu; Zhu, Xiaolong; Jokubavicius, Valdas

    2014-01-01

    We demonstrate a time-efficient and low-cost approach to fabricate Si3N4 coated nanodome structures in fluorescent SiC. Nanosphere lithography is used as the nanopatterning method and SiC nanodome structures with Si3N4 coating are formed via dry etching and thin film deposition process. By using...

  17. A two-in-one superhydrophobic and anti-reflective nanodevice in the grey cicada Cicada orni (Hemiptera)

    Energy Technology Data Exchange (ETDEWEB)

    Dellieu, Louis, E-mail: louis.dellieu@unamur.be; Sarrazin, Michaël, E-mail: michael.sarrazin@unamur.be; Simonis, Priscilla; Deparis, Olivier; Vigneron, Jean Pol [Research Center in Physics of Matter and Radiation (PMR), Department of Physics, University of Namur (FUNDP), 61 rue de Bruxelles, B-5000 Namur (Belgium)

    2014-07-14

    Two separated levels of functionality are identified in the nanostructure which covers the wings of the grey cicada Cicada orni (Hemiptera). The upper level is responsible for superhydrophobic character of the wing, while the lower level enhances its anti-reflective behavior. Extensive wetting experiments with various chemical species and optical measurements were performed in order to assess the bi-functionality. Scanning electron microscopy imaging was used to identify the nanostructure morphology. Numerical optical simulations and analytical wetting models were used to prove the roles of both levels of the nanostructure. In addition, the complex refractive index of the chitinous material of the wing was determined from measurements.

  18. Solution-Processed Nanowire Coating for Light Management in Organic Solar Cells

    Directory of Open Access Journals (Sweden)

    K. Tsuboi

    2012-01-01

    Full Text Available We report a novel light management approach based on solution-processed nanowire (NW coating for enhancing organic solar cell efficiency. A titanium dioxide (TiO2 NW dispersion was produced by electrospinning. The coatings with various coverage fractions were fabricated by a simple solution casting of a TiO2 NW dispersion. Reduced reflectivity was observed for the NW-coated glass slide. The bulk-heterojunction organic solar cells with the NW coating showed improved power conversion efficiencies (PCEs due to their antireflection and light trapping effects in the active layer. In addition, the PCE of the cell with the NW coating was improved compared with that without the NW coating for incident angles above 70° (increased by a maximum of 51.6% at an incident angle of 85°. These results indicate that solution-processed NW coating is a promising light management approach easily scalable and applicable to a wide range of devices, including solar cells.

  19. Characterization of the optical properties of hydrophobic coatings and realization of high performance AR coatings with dust- and water-repellent properties

    Science.gov (United States)

    Bruynooghe, S.; Spinzig, S.; Fliedner, M.; Hsu, G. J.

    2008-09-01

    Hydrophobic coatings enable the manufacture of easy-to-clean surfaces having dust- and water-repellent properties. In this work, a hydrophobic coating is deposited as a top layer on an antireflective (AR) multilayer system comprising a MgF2 upper layer to produce low reflectance optical surfaces at a normal incident angle in the visible spectrum with dust- and water-repellent properties for applications in precision optics. We report on the preparation and characterization of the optical properties of hydrophobic coatings deposited using a vacuum evaporation process and a commercially available water repellent substance. By means of a grazing incidence X-ray reflectometer it is shown that the hydrophobic coating can be considered, from an optical point of view, as two adjacent thin layers having specific thicknesses and densities. In fact, the hydrophobic layer is one monolayer comprising molecular chains with anchoring groups responsible for the chemical bond with the substrate material and functional groups responsible for the water- and oil-repellent properties. Optical constants are determined using a spectroscopic ellipsometer and are taken into account in the final multilayer system design. High performance AR coatings having an average reflectance of 0.14% at 7° incident angle in the 400-680nm spectral range together with a pleasing purple-red reflex color are produced. Coated lenses exhibit an excellent abrasion resistance, environmental stability, resistance to cleaning agents, homogeneity and water repellence with contact angles against water higher than 110°.

  20. Protective Coatings

    Science.gov (United States)

    1980-01-01

    General Magnaplate Corporation's pharmaceutical machine is used in the industry for high speed pressing of pills and capsules. Machine is automatic system for molding glycerine suppositories. These machines are typical of many types of drug production and packaging equipment whose metal parts are treated with space spinoff coatings that promote general machine efficiency and contribute to compliance with stringent federal sanitation codes for pharmaceutical manufacture. Collectively known as "synergistic" coatings, these dry lubricants are bonded to a variety of metals to form an extremely hard slippery surface with long lasting self lubrication. The coatings offer multiple advantages; they cannot chip, peel or be rubbed off. They protect machine parts from corrosion and wear longer, lowering maintenance cost and reduce undesired heat caused by power-robbing friction.

  1. Graphene Coatings

    DEFF Research Database (Denmark)

    Stoot, Adam Carsten; Camilli, Luca; Bøggild, Peter

    2014-01-01

    Owing to its remarkable electrical and mechanical properties, graphene has been attracting tremendous interest in materials science. In particular, its chemical stability and impermeability make it a promising protective membrane. However, recent investigations reveal that single layer graphene...... cannot be used as a barrier in the long run, due to galvanic corrosion phenomena arising when oxygen or water penetrate through graphene cracks or domain boundaries. Here, we overcome this issue by using a multilayered (ML) graphene coating. Our lab- as well as industrial-scale tests demonstrate that ML...... that graphene can still be a relevant candidate for thin coatings....

  2. Fabrication of micro hole array on the surface of CVD ZnS by scanning ultrafast pulse laser for antireflection

    Science.gov (United States)

    Li, Yangping; Zhang, Tianhui; Fan, Siling; Cheng, Guanghua

    2017-04-01

    Chemical vapor deposited (CVD) ZnS is a promising long-wave infrared (8-12 μm) window material. Yet antireflection is necessary since Fresnel reflection from its surface is high due to the high refractive index of ZnS. Sub-wavelength structured surface of micro hole array was fabricated on CVD ZnS by scanning ultrafast pulse laser ablation. The effects of beam profile, pulse width and beam power on the radius and morphology of the holes were studied. Gaussian beam can cause severe melted-resolidified layers around the hole, yet Bessel beam only resulted in thin ribbon around the hole. The picosecond Bessel laser is more suitable than femtosecond laser for ablating holes on ZnS. The radius of the holes increases with increasing the Bessel beam pulse width and the beam power. But larger power may cause circle grooves around the central holes. Ordered hole array was fabricated on single side of CVD ZnS and antireflection was realized.

  3. Double-layered TiO2-SiO2 nanostructured films with self-cleaning and antireflective properties.

    Science.gov (United States)

    Zhang, Xintong; Fujishima, Akira; Jin, Ming; Emeline, Alexei V; Murakami, Taketoshi

    2006-12-21

    Dual function of self-cleaning and antireflection can be created in double-layered TiO2-SiO2 nanostructured films. The film were prepared by (1) layer-by-layer deposition of multilayered SiO2 nanoparticles with polydiallyldimethylammonium (PDDA) cations, (2) layer-by-layer deposition of multilayered titanate nanosheets with polications on PDDA/SiO2 multilayer films, and (3) burning out the polymer and converting titanate nanosheets into TiO2 by hearing at 500 degrees C. The as-prepared films, consisting of a porous SiO2 bottom layer and a dense TiO2 top layer, improved the transmittance of glass or quartz substrates, as demonstrated by transmission spectra collected at normal incidence. The photocatalytic properties of the films were studied by the change of the water contact angle together with the decay of the IR absorption of the hydrocarbon chain of octadecylphosphonic-acid-modified films under 2.6 mW cm-2 UV illumination. Both the antireflective and the photocatalytic properties of the films were dependent on the number of PDDA/nanosheet bilayers deposited. however, excellent surface wettability of the films for water was obtained, independent of the preparation conditions. The experimental findings are discussed in terms of the special structure of the double-layered nanostructured film.

  4. Modeling the absorption behavior of solar thermal collector coatings utilizing graded alpha-C:H/TiC layers.

    Science.gov (United States)

    Gruber, D P; Engel, G; Sormann, H; Schüler, A; Papousek, W

    2009-03-10

    Wavelength selective coatings are of common use in order to enhance the efficiency of devices heated by radiation such as solar thermal collectors. The use of suitable materials and the optimization of coating layer thicknesses are advisable ways to maximize the absorption. Further improvement is achievable by embedding particles in certain layers in order to modify material properties. We focus on optimizing the absorption behavior of a solar collector setup using copper as substrate, a layer of amorphous hydrogenated carbon with embedded titanium carbide particles (a-C:H/TiC), and an antireflection coating of amorphous silicon dioxide (aSiO(2)). For the setup utilizing homogeneous particle distribution, a relative absorption of 90.98% was found, while inhomogeneous particle embedding yielded 98.29%. These results are particularly interesting since until now, absorption of more than 95% was found only by using embedded Cr but not by using the more biocompatible Ti.

  5. Performance Improvement of GaN-Based Flip-Chip White Light-Emitting Diodes with Diffused Nanorod Reflector and with ZnO Nanorod Antireflection Layer

    Directory of Open Access Journals (Sweden)

    Hsin-Ying Lee

    2014-01-01

    Full Text Available The GaN-based flip-chip white light-emitting diodes (FCWLEDs with diffused ZnO nanorod reflector and with ZnO nanorod antireflection layer were fabricated. The ZnO nanorod array grown using an aqueous solution method was combined with Al metal to form the diffused ZnO nanorod reflector. It could avoid the blue light emitted out from the Mg-doped GaN layer of the FCWLEDs, which caused more blue light emitted out from the sapphire substrate to pump the phosphor. Moreover, the ZnO nanorod array was utilized as the antireflection layer of the FCWLEDs to reduce the total reflection loss. The light output power and the phosphor conversion efficiency of the FCWLEDs with diffused nanorod reflector and 250 nm long ZnO nanorod antireflection layer were improved from 21.15 mW to 23.90 mW and from 77.6% to 80.1% in comparison with the FCWLEDs with diffused nanorod reflector and without ZnO nanorod antireflection layer, respectively.

  6. Optimization of textured-dielectric coatings for crystalline-silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Gee, J.M. [Sandia National Labs., Albuquerque, NM (United States). Photovoltaic System Components Dept.; Gordon, R.; Liang, H. [Harvard Univ., Cambridge, MA (United States). Dept. of Chemistry

    1996-07-01

    The authors report on the optimization of textured-dielectric coatings for reflectance control in crystalline-silicon (c-Si) photovoltaic modules. Textured-dielectric coatings reduce encapsulated-cell reflectance by promoting optical confinement in the module encapsulation; i.e., the textured-dielectric coating randomizes the direction of rays reflected from the dielectric and from the c-Si cell so that many of these reflected rays experience total internal reflection at the glass-air interface. Some important results of this work include the following: the authors demonstrated textured-dielectric coatings (ZnO) deposited by a high-throughput low-cost deposition process; they identified factors important for achieving necessary texture dimensions; they achieved solar-weighted extrinsic reflectances as low as 6% for encapsulated c-Si wafers with optimized textured-ZnO coatings; and they demonstrated improvements in encapsulated cell performance of up to 0.5% absolute compared to encapsulated planar cells with single-layer antireflection coatings.

  7. 仿生纳米减反结构的制备%Fabrication of Biomimetic Antireflective Nano Structures

    Institute of Scientific and Technical Information of China (English)

    李腾; 丁剑; 范同祥

    2012-01-01

    The mechanism, fabrication and the reduction of reflection achieved of four types of bioinspired antireflective structures, namely the ordered nano array, the inordered nano structure, the hierarchical nano structure and the butterfly scale structure,are reviewed. The possible way of further research with the combination of computer simulation and optimization as well as the improvement of fabrication process is proposed.%综述了有序纳米阵列、无序纳米结构、分级纳米结构和蝶翅鳞片结构4类结构的减反机理、制备方法以及实现的性能,并提出计算模拟优化与制备工艺改进的结合是进一步研究的思路.

  8. Optical simulations for fractional fluorine terminated coatings on nanoimprint lithography masks

    Science.gov (United States)

    Seidel, Thomas E.; Goldberg, Alexander; Halls, Mathew D.

    2015-10-01

    Simulations of the optical intensity within Nano Imprint Lithography (NIL) mask features have been made for patterned quartz masks having ultrathin film coatings with different indices of refraction. Fractionally fluorine terminated surfaces, previously proposed for improving the yield of NIL processes, are briefly reviewed. Optical intensity solutions within the feature were obtained using Panoramictech Maxwell solver software for variances in the optical constants of the coating films, aspect ratio, feature size, and wavelength.. The coated masks have conformal surface, higher index of refraction under-layer coating and a fractional terminated fluorine hydrocarbon (FHC) monomolecular layer. The values of optical constants for the FHC layers are unknown, so a range of ad-hoc values were simulated. Optical constants for quartz mask and Al2O3, TiO2 and Si under-layer films are taken from the literature. Wavelengths were varied from 193nm to 365nm. The question of photo-dissociation of the FHC layer for higher energy photons is addressed from first principles, with the result that the F-terminated layers are stable at higher wavelengths. Preliminary simulations for features filled with resist over various substrates are dependent on the antireflection character of the underlying film system. The optical intensity is generally increased within the simulated mask feature when coated with a higher index/FHC films relative to the uncoated reference quartz mask for ~5nm physical feature sizes.

  9. Spectral reflectance data of a high temperature stable solar selective coating based on MoSi2–Si3N4

    Directory of Open Access Journals (Sweden)

    D. Hernández-Pinilla

    2016-06-01

    Full Text Available Data of optical performance, thermal stability and ageing are given for solar selective coatings (SSC based on a novel MoSi2–Si3N4 absorbing composite. SSC have been prepared as multilayer stacks formed by silver as metallic infrared reflector, a double layer composite and an antireflective layer (doi: 10.1016/j.solmat.2016.04.001 [1]. Spectroscopic reflectance data corresponding to the optical performance of samples after moderate vacuum annealing at temperatures up to 600 °C and after ageing test of more than 200 h with several heating–cooling cycles are shown here.

  10. Spectral reflectance data of a high temperature stable solar selective coating based on MoSi2–Si3N4

    Science.gov (United States)

    Hernández-Pinilla, D.; Rodríguez-Palomo, A.; Álvarez-Fraga, L.; Céspedes, E.; Prieto, J.E.; Muñoz-Martín, A.; Prieto, C.

    2016-01-01

    Data of optical performance, thermal stability and ageing are given for solar selective coatings (SSC) based on a novel MoSi2–Si3N4 absorbing composite. SSC have been prepared as multilayer stacks formed by silver as metallic infrared reflector, a double layer composite and an antireflective layer (doi: 10.1016/j.solmat.2016.04.001 [1]). Spectroscopic reflectance data corresponding to the optical performance of samples after moderate vacuum annealing at temperatures up to 600 °C and after ageing test of more than 200 h with several heating–cooling cycles are shown here. PMID:27182544

  11. Spectral reflectance data of a high temperature stable solar selective coating based on MoSi2 -Si3N4.

    Science.gov (United States)

    Hernández-Pinilla, D; Rodríguez-Palomo, A; Álvarez-Fraga, L; Céspedes, E; Prieto, J E; Muñoz-Martín, A; Prieto, C

    2016-06-01

    Data of optical performance, thermal stability and ageing are given for solar selective coatings (SSC) based on a novel MoSi2-Si3N4 absorbing composite. SSC have been prepared as multilayer stacks formed by silver as metallic infrared reflector, a double layer composite and an antireflective layer (doi: 10.1016/j.solmat.2016.04.001 [1]). Spectroscopic reflectance data corresponding to the optical performance of samples after moderate vacuum annealing at temperatures up to 600 °C and after ageing test of more than 200 h with several heating-cooling cycles are shown here.

  12. Corrosion resistant coating

    Science.gov (United States)

    Wrobleski, Debra A.; Benicewicz, Brian C.; Thompson, Karen G.; Bryan, Coleman J.

    1997-01-01

    A method of protecting a metal substrate from corrosion including coating a metal substrate of, e.g., steel, iron or aluminum, with a conductive polymer layer of, e.g., polyaniline, coating upon said metal substrate, and coating the conductive polymer-coated metal substrate with a layer of a topcoat upon the conductive polymer coating layer, is provided, together with the resultant coated article from said method.

  13. Coatings and Corrosion Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Purpose: The mission of the Coatings and Corrosion Laboratory is to develop and analyze the effectiveness of innovative coatings test procedures while evaluating the...

  14. Enhanced conversion efficiency and surface hydrophobicity of nano-roughened Teflon-like film coated poly-crystalline Si solar cells.

    Science.gov (United States)

    Lin, Gong-Ru; Meng, Fan-Shuen; Pai, Yi-Hao; Lin, Yung-Hsiang

    2012-03-21

    Nano-roughened Teflon-like film coated poly-crystalline Si photovoltaic solar cells (PVSCs) with enhanced surface hydrophobicity and conversion efficiency (η) are characterized and compared with those coated by a Si nanorod array or a standard SiN anti-reflection layer. The Teflon-like film coated PVSC surface reveals a water contact angle increasing from 89.3° to 96.2° as its thickness enlarges from 22 to 640 nm, which is much larger than those of the standard and Si nanorod array coated PVSC surfaces (with angles of 55.6° and 32.8°, respectively). After nano-roughened Teflon-like film passivation, the PVSC shows a comparable η(10.89%) with the standard SiN coated PVSC (η = 11.39%), while the short-circuit current (I(SC)) is slightly reduced by 2% owing to the slightly decreased UV transmittance and unchanged diode performance. In contrast, the Si nanorod array may offer an improved surface anti-reflection with surface reflectance decreasing from 30% to 5% at a cost of optical scattering and randomized deflection, which simultaneously decrease the optical transmittance from 15% to 3% in the visible region without improving hydrophobicity and conversion efficiency. The Si nanorod array covered PVSC with numerous surface dangling bonds induced by 1 min wet-etching, which greatly reduces the open-circuit voltage (V(OC)) by 10-15% and I(SC) by 30% due to the reduced shunt resistance from 3 to 0.24 kΩ. The nano-scale roughened Teflon-like film coated on PVSC has provided better hydrophobicity and conversion efficiency than the Si nanorod array covered PVSC, which exhibits superior water repellant performance and comparable conversion efficiency to be one alternative approach for self-cleaning PVSC applications.

  15. Fabrication of Polymeric Antireflection Film Manufactured by Anodic Aluminum Oxide Template on Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Jenn-Kai Tsai

    2017-03-01

    Full Text Available In this study, high energy conversion efficient dye-sensitized solar cells (DSSCs were successfully fabricated by attaching a double anti-reflection (AR layer, which is composed of a subwavelength moth-eye structured polymethyl methacrylate (PMMA film and a polydimethylsiloxane (PDMS film. An efficiency of up to 6.79% was achieved. The moth-eye structured PMMA film was fabricated by using an anodic aluminum oxide (AAO template which is simple, low-cost and scalable. The nano-pattern of the AAO template was precisely reproduced onto the PMMA film. The photoanode was composed of Titanium dioxide (TiO2 nanoparticles (NPs with a diameter of 25 nm deposited on the fluorine-doped tin oxide (FTO glass substrate and the sensitizer N3. The double AR layer was proved to effectively improve the short-circuit current density (JSC and conversion efficiency from 14.77 to 15.79 mA/cm2 and from 6.26% to 6.79%, respectively.

  16. Forming the graded-refractive-index antireflection layers on light-emitting diodes to enhance the light extraction.

    Science.gov (United States)

    Cho, Joong-Yeon; Byeon, Kyeong-Jae; Lee, Heon

    2011-08-15

    Distributed antireflection (AR) layers with different composition ratios of ITO and SiO(2) formed on an ITO electrode of GaN-based LEDs provide substantial enhancement in light-extraction efficiency. By using the coradio frequency magnetron sputtering deposition, four 50 nm thick AR layers with graduated refractive indices were fabricated. The effect of the AR layers on enhancing the efficiency of the LED device was analyzed by electroluminescence (EL) and I-V measurements. As a result, the EL intensity of the LED device grown on the patterned sapphire substrate with AR layers was increased by up to 13% compared to the conventional patterned sapphire substrate-applied LED device without AR layers at a drive current of 20 mA. The AR layers on top of the LED device gradually changed the refractive indices between ITO (n=2.1) and air (n=1.0), which minimized the total internal reflection of generated light. And no degradation in the electrical characteristic of the LEDs was observed according to the I-V measurements.

  17. Effects of pattern size, dual side patterning, and imprint materials in the fabrication of antireflective structure using nanoimprint

    Science.gov (United States)

    Choi, Dae-Geun; Lee, Ki-Jung; Kim, Ki-Don; Choi, Jun-Hyuk; Jeong, Jun-Ho; Lee, Eung-Sug

    2008-08-01

    One of the useful applications using NIL is the fabrication of antireflection structure (ARS) which has a sub-wavelength nanostructure similar to moth-eye below wavelength of visible light because the ARS can be used in anti-glare monitor, dashboards, and solar cells. The material selection of mold and resin in the NIL process for ARS is very important for the purpose of real application and mass production. Generally, the mold should have flexibility for continuous mass production and final structure should have strong durability under outdoor environment. In this work, the effect of single side and dual side patterning were investigated by change of pitch from moth-eye to photonic crystal on the flexible polymer substrate by using NIL. Then, the effect of fluorine resin with low refractive index was tested. Finally, a fabrication method of ARS of pitch of 250nm with high fidelity and accuracy using the high-resolution PDMS mold by aid of solvent mixing of low viscosity was presented. Generally, it is difficult for Sylgard PDMS to make nanopattern below 300nm pitch without special treatment.

  18. Hydro-oleophobic silica antireflective films with high laser-damage threshold

    Science.gov (United States)

    Yan, Lianghong; Lv, Haibing; Wang, Chengcheng; Yuan, Xiaodong

    2011-02-01

    A simple method of preparing hydro-oleophobic anitreflective films with high laser-damage threshold is reported in this article. By adding fluoroalkylsilanes (FAS) into reactant mixture as a co-precursor, FAS modified SiO 2 was obtained under base catalyzed hydrolysis and condensation of tetraethoxysilane. The dip-coating films were deposited on two sides of fused silica substrates. The experimental results on the effect of adding fluoroalkylsilanes (FAS) as a co-precursor on the hydro-oleophobicity and optical properties of tetraethoxysilane (TEOS) based silica AR films, are reported. The hydro-oleophobicity of the films was tested by the contact angle measurements and the highest water contact angle of 136° and oil (peanut) contact angle of 93° were obtained. The surface chemical modification of the hydro-oleophobic films was confirmed using Fourier transform infrared spectroscopy (FTIR). For the films based on FAS and TEOS, additional absorption bands at 1100 cm -1 corresponding to C-F bond presented, clearly indicating the organic modification of the films. The highest optical transmittance of the hydro-oleophobic films was found to be 99.5%. By a Nd:YAG lasers the laser-damage threshold of as-deposited films was measured at 351 nm wavelength (1 ns). The laser-damage threshold was as high as 22.6 J/cm 2.

  19. Coating of pumps; coating af pumper

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Hans; Moritzen, J.; Thoegersen, Jeanette

    2005-11-15

    Coating of pumps is a quite new activity. For many years pipes and containers have been coated inside in order to avoid corrosion, but the technology has only been used inside pumps for the last ten years. The technology comes from USA and is originally developed in the space technology industry as an exceptionally durable and corrosion constant coating. The project is a further development of results found in a previous R and D project in which measurements were performed before and after coating two different installations. Both installations showed large efficiency improvements. This project supplements the theory behind losses in pumps with measurements on more pumps. (BA)

  20. SiC protective coating for photovoltaic retinal prosthesis

    Science.gov (United States)

    Lei, Xin; Kane, Sheryl; Cogan, Stuart; Lorach, Henri; Galambos, Ludwig; Huie, Philip; Mathieson, Keith; Kamins, Theodore; Harris, James; Palanker, Daniel

    2016-08-01

    Objective. To evaluate plasma-enhanced, chemically vapor deposited (PECVD) amorphous silicon carbide (α-SiC:H) as a protective coating for retinal prostheses and other implantable devices, and to study their failure mechanisms in vivo. Approach. Retinal prostheses were implanted in rats sub-retinally for up to 1 year. Degradation of implants was characterized by optical and scanning electron microscopy. Dissolution rates of SiC, SiN x and thermal SiO2 were measured in accelerated soaking tests in saline at 87 °C. Defects in SiC films were revealed and analyzed by selectively removing the materials underneath those defects. Main results. At 87 °C SiN x dissolved at 18.3 ± 0.3 nm d-1, while SiO2 grown at high temperature (1000 °C) dissolved at 0.104 ± 0.008 nm d-1. SiC films demonstrated the best stability, with no quantifiable change after 112 d. Defects in thin SiC films appeared primarily over complicated topography and rough surfaces. Significance. SiC coatings demonstrating no erosion in accelerated aging test for 112 d at 87 °C, equivalent to about 10 years in vivo, can offer effective protection of the implants. Photovoltaic retinal prostheses with PECVD SiC coatings exhibited effective protection from erosion during the 4 month follow-up in vivo. The optimal thickness of SiC layers is about 560 nm, as defined by anti-reflective properties and by sufficient coverage to eliminate defects.

  1. Characterisation Studies of the Structure and Properties of As-Deposited and Annealed Pulsed Magnetron Sputtered Titania Coatings

    Directory of Open Access Journals (Sweden)

    John A. Ridealgh

    2013-09-01

    Full Text Available Titanium dioxide thin films are durable, chemically stable, have a high refractive index and good electro/photochemical proprieties. Consequently, they are widely used as anti-reflective layers in optical devices and large area glazing products, dielectric layers in microelectronic devices and photo catalytic layers in self-cleaning surfaces. Titania coatings may have amorphous or crystalline structures, where three crystalline phases of TiO2 can be obtained: anatase, rutile and brookite, although the latter is rarely found. It is known, however, that the structure of TiO2 coatings is sensitive to deposition conditions and can also be modified by post-deposition heat treatments. In this study, titania coatings have been deposited onto soda-lime glass substrates by reactive sputtering from a metallic target. The magnetron was driven in mid-frequency pulsed DC mode. The as-deposited coatings were analysed by micro Raman spectroscopy, X-ray diffraction (XRD, atomic force microscopy (AFM and scanning electron microscopy (SEM. Selected coatings were annealed at temperatures in the range 200–700 °C and re-analysed. Whilst there was weak evidence of a nanocrystallinity in the as-deposited films, it was observed that these largely amorphous low temperature structures converted into strongly crystalline structures at annealing temperatures above 400 °C.

  2. Fabrication of High Transparency Diamond-Like Carbon Film Coating on D263T Glass at Room Temperature as an Antireflection Layer

    Directory of Open Access Journals (Sweden)

    Chii-Ruey Lin

    2013-01-01

    Full Text Available This study intends to deposit high transmittance diamond-like carbon (DLC thin films on D263T glass substrate at room temperature via a diamond powder target using the radio frequency (RF magnetron sputtering technique. Moreover, various process parameters were used to tune the properties of the thin films by using the Taguchi method. Experimental results show that the content of sp3 bonded carbon decreases in accordance with the effect of the substrate temperature. In addition, the hardness of all as-deposited single-layer DLC films ranges from 13.2 to 22.5 GPa, and the RMS surface roughness was improved significantly with the decrease in sputtering pressure. The water repellent of the deposited DLC films improved significantly with the increase of the sp3 content, and its contact angle was larger than that of the noncoated one by 1.45 times. Furthermore, the refraction index (n of all as-deposited DLC films ranges from 1.95 to 2.1 at λ = 600 nm. These results demonstrate that the thickness increased as the reflectance increased. DLC film under an RF power of 150 W possesses high transmissive ability (>81% and low average reflectance ability (<9.5% in the visible wavelengths (at λ = 400–700 nm.

  3. 以sol-gel技术制备太阳能减反射涂层%Solar antireflective coating made with sol-gel technology

    Institute of Scientific and Technical Information of China (English)

    雷振宇

    2009-01-01

    着重介绍了sol-gel(熔胶-凝胶)技术大面积、工业化制备高硬度、耐摩擦太阳能减反射涂层的意义、原理和方法,并从其作为商品工业化的角度,介绍了SiO2单层膜系和TiO2-SiO2双层膜系太阳能减反射涂层生产工艺、设备及环境要求等,给出了部分商业化减反射涂层的性能特征等技术参数.

  4. Antireflective coating for AgBr-TlI and AgBr-TlBr0.46I0.54 solid solution crystals

    Science.gov (United States)

    Korsakov, Alexandr; Salimgareev, Dmitrii; Lvov, Alexandr; Zhukova, Liya

    2016-12-01

    We researched the process of ultraviolet (UV) irradiation for the crystals of AgBr-TlI and AgBr-TlBr0.46I0.54 systems. It was found that on the surface of irradiated crystals, the film is formed and film grain size depends on exposure time and crystal composition. This film proved to gain the transmission by reducing the reflection from its surface within the 8.0-27.0 μm range.

  5. Preparation of Hydro-oleophobic Silica Antireflective Coating%疏水疏油二氧化硅增透膜的制备

    Institute of Scientific and Technical Information of China (English)

    晏良宏; 匙芳廷; 蒋晓东; 吕海兵; 袁晓东; 江波

    2007-01-01

    以正硅酸乙酯为前驱体,氨水为催化剂,采用溶胶-凝胶法,结合全氟辛基癸烷三甲氧基硅烷(FAS)自组装对膜层表面改性,制备了疏水疏油二氧化硅增透膜.采用红外光谱仪,分光光度计,扫描探针显微镜,椭偏仪,静滴接触角测量仪,抗油污染能力测试等技术对膜层性质进行了分析.结果表明:疏水疏油增透膜的峰值透光率为99.8%;与水的接触角为118.0°,与二甲基硅油的接触角达到74.5°;在抗油污染能力测试中,疏水疏油增透膜的抗油污染能力较常规增透膜大大增强.

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

    Institute of Scientific and Technical Information of China (English)

    尤大伟; 李晓谦; 王宇; 林永昌

    2004-01-01

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

  7. Commercial Fastener Coatings Doerken

    Science.gov (United States)

    2010-06-01

    Phosphating* *partly recommended Dip Spinning Dipping Spraying Spin coating Conveyor oven box oven Inductive drying Pretreatment Coating Preheating...Curing Cooling Application Techniques - Dip Spin Coating Gurtbnd Cross BarTranspo" Band beiCifteiE Vo12one Vent llated Pre .Zone Cros~ Bar T ransrt

  8. PIT Coating Requirements Analysis

    Energy Technology Data Exchange (ETDEWEB)

    MINTEER, D.J.

    2000-10-20

    This study identifies the applicable requirements for procurement and installation of a coating intended for tank farm valve and pump pit interior surfaces. These requirements are intended to be incorporated into project specification documents and design media. This study also evaluates previously recommended coatings and identifies requirement-compliant coating products.

  9. Surfaces, Coatings and Protection

    Science.gov (United States)

    Ferguson, I. F.

    1982-08-01

    Plasma sprayed ceramics, sputter ion plating, and sol-gel ceramic protective coatings for nuclear reactors are discussed. The influence of such coatings on the behavior of reactor fuel elements is noted. The investigation of such coatings by diffraction methods is described. Laser and nuclear microprobes, scanning transmission electron microscopes, neutron scattering, and image analysis are summarized.

  10. Hard and superhard nanocomposite coatings

    Energy Technology Data Exchange (ETDEWEB)

    Musil, J. [Univ. of West Bohemia, Plzen (Czech Republic). Dept. of Phys.

    2000-03-01

    This article reviews the development of hard coatings from a titanium nitride film through superlattice coatings to nanocomposite coatings. Significant attention is devoted to hard and superhard single layer nanocomposite coatings. A strong correlation between the hardness and structure of nanocomposite coatings is discussed in detail. Trends in development of hard nanocomposite coatings are also outlined. (orig.)

  11. Antireflective sub-wavelength structures for improvement of the extraction efficiency and color rendering index of monolithic white light-emitting diode

    DEFF Research Database (Denmark)

    Ou, Yiyu; Corell, Dennis Dan; Dam-Hansen, Carsten

    2011-01-01

    We have theoretically investigated the influence of antireflective sub-wavelength structures on a monolithic white light-emitting diode (LED). The simulation is based on the rigorous coupled wave analysis (RCWA) algorithm, and both cylinder and moth-eye structures have been studied in the work. Our...... (CRI) and the correlated color temperature (CCT) of the monolithic white LED have been demonstrated. The CRI of the monolithic white LED could be improved from 92.68 to around 94 by applying a cylinder structure, and the CCT could be modified in a very large range with appropriate design...

  12. Specific features of current flow mechanisms in the semiconductor structure of a photoelectric converter with an n +- p-junction and an antireflective porous silicon film

    Science.gov (United States)

    Tregulov, V. V.; Stepanov, V. A.; Litvinov, V. G.; Ermachikhin, A. V.

    2016-11-01

    The temperature dependence of forward and reverse branches of the current-voltage characteristic of the semiconductor structure of a photoelectric converter with an n +- p-junction based on single-crystal silicon and an antireflective porous silicon film on the front surface has been studied. The presence of several current flow mechanisms has been revealed. It has been demonstrated that traps that emerge in the process of the formation of the porous silicon film have a considerable effect on the current flow processes in the semiconductor structure under consideration.

  13. Recent progress in optical coating technology: low-voltage ion plating deposition

    Science.gov (United States)

    Guenther, Karl H.

    1990-08-01

    After fairly extensive discussions of the advantages and disadvantages of low energy and high energy ion beam bombardment of a growing film, we review briefly a number of experimental results obtained with various samples made with low voltage reactive ion plating deposition. The availability of a state-of-the-art high vacuum coating machine specifically equipped for this process is the foundation for a major leap toward achieving near-perfect optical coatings. The high density of ion plated thin films makes them impermeable to water vapor and corrosive solutions. This has been demonstrated with protected aluminum mirrors, polarizers, and infrared anti-reflection coatings. An indication of the high packing density is the substantially higher refractive index than that of comparable layers deposited with either conventional electron beam evaporation or ion assisted deposition. The spectral transmittance of multilayer stacks of oxide thin films is lower than expected from theoretical predictions which assume absorption-free dielectrics. The observed absorption is primarily of an interface nature rather than a volume effect and occurs predominantly in combinations of Ti02 and Si02 thin films.

  14. pH-Switchable Stratification of Colloidal Coatings: Surfaces "On Demand".

    Science.gov (United States)

    Martín-Fabiani, Ignacio; Fortini, Andrea; Lesage de la Haye, Jennifer; Koh, Ming Liang; Taylor, Spencer E; Bourgeat-Lami, Elodie; Lansalot, Muriel; D'Agosto, Franck; Sear, Richard P; Keddie, Joseph L

    2016-12-21

    Stratified coatings are used to provide properties at a surface, such as hardness or refractive index, which are different from underlying layers. Although time-savings are offered by self-assembly approaches, there have been no methods yet reported to offer stratification on demand. Here, we demonstrate a strategy to create self-assembled stratified coatings, which can be switched to homogeneous structures when required. We use blends of large and small colloidal polymer particle dispersions in water that self-assemble during drying because of an osmotic pressure gradient that leads to a downward velocity of larger particles. Our confocal fluorescent microscopy images reveal a distinct surface layer created by the small particles. When the pH of the initial dispersion is raised, the hydrophilic shells of the small particles swell substantially, and the stratification is switched off. Brownian dynamics simulations explain the suppression of stratification when the small particles are swollen as a result of reduced particle mobility, a drop in the pressure gradient, and less time available before particle jamming. Our strategy paves the way for applications in antireflection films and protective coatings in which the required surface composition can be achieved on demand, simply by adjusting the pH prior to deposition.

  15. Antibacterial polymer coatings.

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Mollye C.; Allen, Ashley N.; Barnhart, Meghan; Tucker, Mark David; Hibbs, Michael R.

    2009-09-01

    A series of poly(sulfone)s with quaternary ammonium groups and another series with aldehyde groups are synthesized and tested for biocidal activity against vegetative bacteria and spores, respectively. The polymers are sprayed onto substrates as coatings which are then exposed to aqueous suspensions of organisms. The coatings are inherently biocidal and do not release any agents into the environment. The coatings adhere well to both glass and CARC-coated coupons and they exhibit significant biotoxicity. The most effective quaternary ammonium polymers kills 99.9% of both gram negative and gram positive bacteria and the best aldehyde coating kills 81% of the spores on its surface.

  16. Anticorrosive coatings: a review

    DEFF Research Database (Denmark)

    Sørensen, Per Aggerholm; Kiil, Søren; Dam-Johansen, Kim

    2009-01-01

    The main objective of this review is to describe some of the important topics related to the use of marine and protective coatings for anticorrosive purposes. In this context, "protective" refers to coatings for containers, offshore constructions, wind turbines, storage tanks, bridges, rail cars......, and petrochemical plants while "marine" refers to coatings for ballast tanks, cargo holds and cargo tanks, decks, and engine rooms on ships. The review aims at providing a thorough picture of state-of-the-art in anticorrosive coatings systems. International and national legislation aiming at reducing the emission...... of volatile organic compounds (VOCs) have caused significant changes in the anticorrosive coating industry. The requirement for new VOC-compliant coating technologies means that coating manufacturers can no longer rely on the extensive track record of their time-served products to convince consumers...

  17. Combustion chemical vapor desposited coatings for thermal barrier coating systems

    Energy Technology Data Exchange (ETDEWEB)

    Hampikian, J.M.; Carter, W.B. [Georgia Institute of Technology, Atlanta, GA (United States)

    1995-10-01

    The new deposition process, combustion chemical vapor deposition, shows a great deal of promise in the area of thermal barrier coating systems. This technique produces dense, adherent coatings, and does not require a reaction chamber. Coatings can therefore be applied in the open atmosphere. The process is potentially suitable for producing high quality CVD coatings for use as interlayers between the bond coat and thermal barrier coating, and/or as overlayers, on top of thermal barrier coatings.

  18. Zr-ZrO sub 2 cermet solar coatings designed by modelling calculations and deposited by dc magnetron sputtering

    CERN Document Server

    Zhang Qi Chu; Lee, K D; Shen, Y G

    2003-01-01

    High solar performance Zr-ZrO sub 2 cermet solar coatings were designed using a numerical computer model and deposited experimentally. The layer thickness and Zr metal volume fraction for the Zr-ZrO sub 2 cermet solar selective coatings on a Zr or Al reflector with a surface ZrO sub 2 or Al sub 2 O sub 3 anti-reflection layer were optimized to achieve maximum photo-thermal conversion efficiency at 80 deg. C under concentration factors of 1-20 using the downhill simplex method in multi-dimensions in the numerical calculation. The dielectric function and the complex refractive index of Zr-ZrO sub 2 cermet materials were calculated using Sheng's approximation. Optimization calculations show that Al sub 2 O sub 3 /Zr-ZrO sub 2 /Al solar coatings with two cermet layers and three cermet layers have nearly identical solar absorptance, emittance and photo-thermal conversion efficiency that are much better than those for films with one cermet layer. The optimized Al sub 2 O sub 3 /Zr-ZrO sub 2 /Al solar coating film w...

  19. Inhomogeneity in Spectral Transmission of the Coated UB VRI Filters of BFOSC and its Influence on Photometry

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In order to realize the Johnson UBV and Kron-Cousins RI photometricsystems in BFOSC, glass filters were purchased according to the Bessell prescription.All the filters are anti-reflection coated on both sides to increase the transmission.By comparing two dome fiat-field exposures taken through any one of these filtersset in two orientations 90~ apart, inhomogeneities in the filter transmission is dearlydemonstrated. Using a PDS microphotometer, we have confirmed that the form oftheir spectral transmission curve varied from point to point on the filters. Thiskind of inhomogeneity cannot be eliminated by dividing by fiat-fielding exposureand must be ascribed to inhomogeneities in the coating. This is not some acciden-tal defect in coating, it is in the existing coating technique because all the filters(including the narrow-band interference ones) for the BFOSC and a Hβ filter madeby another manufacturer showed a similar pattern. We found that for the studies ofvariable stars with amplitudes less than 0.05 mag. or studies aiming at establishingaccurate C-M diagrams of star clusters, the usual uncoated Schott glass filters ofBessell's prescription are to be preferred.

  20. Hydrothermal Synthesis Au-Bi2Te3 Nanocomposite Thermoelectric Film with a Hierarchical Sub-Micron Antireflection Quasi-Periodic Structure

    Directory of Open Access Journals (Sweden)

    Junlong Tian

    2015-06-01

    Full Text Available In this work, Au-Bi2Te3 nanocomposite thermoelectric film with a hierarchical sub-micron antireflection quasi-periodic structure was synthesized via a low-temperature chemical route using Troides helena (Linnaeus forewing (T_FW as the biomimetic template. This method combines chemosynthesis with biomimetic techniques, without the requirement of expensive equipment and energy intensive processes. The microstructure and the morphology of the Au-Bi2Te3 nanocomposite thermoelectric film was analyzed by X-ray diffraction (XRD, field-emission scanning-electron microscopy (FESEM, and transmission electron microscopy (TEM. Coupled the plasmon resonances of the Au nanoparticles with the hierarchical sub-micron antireflection quasi-periodic structure, the Au-Bi2Te3 nanocomposite thermoelectric film possesses an effective infrared absorption and infrared photothermal conversion performance. Based on the finite difference time domain method and the Joule effect, the heat generation and the heat source density distribution of the Au-Bi2Te3 nanocomposite thermoelectric film were studied. The heterogeneity of heat source density distribution of the Au-Bi2Te3 nanocomposite thermoelectric film opens up a novel promising technique for generating thermoelectric power under illumination.

  1. 蓝宝石红外窗口抗反射浮雕结构研究%Study on Antireflective Relief Periodic Structure of Sapphire Infrared Window

    Institute of Scientific and Technical Information of China (English)

    孙艳军; 冷雁冰; 董连和

    2011-01-01

    Subwavelength periodic structure on infrared material can achieve antirefiective function at infrared band. In harsh environment, infrared window may replace infrared antireflective film. And it can provide corrosion resistance, shock resistance, etc. This paper describe the design of subwavelength relief unit structure using effective medium theory, and fabrication of the relief structure on the surface of sapphire material by photolithograph and ion etching. The infrared transmittance improved about 10 percent. The relation of antireflective and Periodic, filling cycle, and unit depth etc are analyzed.%采用相应技术,在红外材料表面制成的亚波长浮雕结构能实现红外波段的减反功能.在恶劣环境中,红外窗口采用该结构代替红外减反膜能够提高其抗蚀、抗冲击等性能.通过等效媒质理论设计亚波长浮雕单元结构,采用光刻及离子蚀刻方法完成蓝宝石材料表面浮雕结构制作,经测试红外透过率整体提高大约10%.经分析,浮雕结构的周期、占空比、单元深度等因素都对减反结果影响很大.

  2. Development of technique for AR coating and nickel and copper metallization of solar cells. FPS Project: Product development

    Science.gov (United States)

    Taylor, W.

    1982-01-01

    Printed nickel overplated with copper and applied on top of a predeposited silicon nitride antireflective coating system for metallizing solar cells was analyzed. The ESL D and E paste formulations, and the new formulations F, G, H, and D-1 were evaluated. The nickel thick films were tested after firing for stability in the cleaning and plating solutions used in the Vanguard-Pacific brush plating process. It was found that the films are very sensitive to the leaning and alkaline copper solutions. Less sensitivity was displayed to the neutral copper solution. Microscopic and SEM observations show segregation of frit at the silicon nitride thick film interface with loose frit residues after lifting off plated grid lines.

  3. Electrospark deposition coatings

    Science.gov (United States)

    Sheely, W. F.

    1986-11-01

    Hard surfacing for wear resistant and low-friction coatings has been improved by means of advances in the computer controls in electronic circuitry of the electrospark deposition (ESD) process. coatings of nearly any electrically conductive metal alloy or cermet can be deposited on conductive materials. Thickness is usually two mils or less, but can be as high as 10 mils. ESD coatings can quadrupole cutting tool life.

  4. Oxide coating development

    Energy Technology Data Exchange (ETDEWEB)

    Stinton, D.P.

    1995-06-01

    Monolithic SiC heat exchangers and fiber-reinforced SiC-matrix composite heat exchangers and filters are susceptible to corrosion by alkali metals at elevated temperatures. Protective coatings are currently being developed to isolate the SiC materials from the corrodants. Unfortunately, these coatings typically crack and spall when applied to SiC substrates. The purpose of this task is to determine the feasibility of using a compliant material between the protective coating and the substrate. The low-modulus compliant layer could absorb stresses and eliminate cracking and spalling of the protective coatings.

  5. Superhard Nanocomposite Coatings

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The recent development in the field of nanocomposite coatings with good mechanical properties is critically reviewed in this paper. The design principle and materials selection for the nanocomposite coatings are introduced. Different methods for the preparation of superhard nanocomposite coatings are described with emphasis on the magnetron sputtering. Based on recent theoretical and experimental results regarding the appearance of superhardness in nanocomposite coating, lattice parameter changes, crystallite size, microstructure and morphology are reviewed in detail. Also emphasized are the mechanical properties (especially on hardness) and the ways by which the properties are derived.

  6. Combustion chemical vapor deposited coatings for thermal barrier coating systems

    Energy Technology Data Exchange (ETDEWEB)

    Hampikian, J.M.; Carter, W.B. [Georgia Institute of Technology, Atlanta, GA (United States). School of Materials Science and Engineering

    1995-12-31

    The new deposition process, combustion chemical vapor deposition, shows a great deal of promise in the area of thermal barrier coating systems. This technique produces dense, adherent coatings, and does not require a reaction chamber. Coatings can therefore be applied in the open atmosphere. The process is potentially suitable for producing high quality CVD coatings for use as interlayers between the bond coat and thermal barrier coating, and/or as overlayers, on top of thermal barrier coatings. In this report, the evaluation of alumina and ceria coatings on a nickel-chromium alloy is described.

  7. Al2O3/SiON stack layers for effective surface passivation and anti-reflection of high efficiency n-type c-Si solar cells

    Science.gov (United States)

    Thi Thanh Nguyen, Huong; Balaji, Nagarajan; Park, Cheolmin; Triet, Nguyen Minh; Le, Anh Huy Tuan; Lee, Seunghwan; Jeon, Minhan; Oh, Donhyun; Dao, Vinh Ai; Yi, Junsin

    2017-02-01

    Excellent surface passivation and anti-reflection properties of double-stack layers is a prerequisite for high efficiency of n-type c-Si solar cells. The high positive fixed charge (Q f) density of N-rich hydrogenated amorphous silicon nitride (a-SiNx:H) films plays a poor role in boron emitter passivation. The more the refractive index ( n ) of a-SiNx:H is decreased, the more the positive Q f of a-SiNx:H is increased. Hydrogenated amorphous silicon oxynitride (SiON) films possess the properties of amorphous silicon oxide (a-SiOx) and a-SiNx:H with variable n and less positive Q f compared with a-SiNx:H. In this study, we investigated the passivation and anti-reflection properties of Al2O3/SiON stacks. Initially, a SiON layer was deposited by plasma enhanced chemical vapor deposition with variable n and its chemical composition was analyzed by Fourier transform infrared spectroscopy. Then, the SiON layer was deposited as a capping layer on a 10 nm thick Al2O3 layer, and the electrical and optical properties were analyzed. The SiON capping layer with n = 1.47 and a thickness of 70 nm resulted in an interface trap density of 4.74 = 1010 cm-2 eV-1 and Q f of -2.59 = 1012 cm-2 with a substantial improvement in lifetime of 1.52 ms after industrial firing. The incorporation of an Al2O3/SiON stack on the front side of the n-type solar cells results in an energy conversion efficiency of 18.34% compared to the one with Al2O3/a-SiNx:H showing 17.55% efficiency. The short circuit current density and open circuit voltage increase by up to 0.83 mA cm-2 and 12 mV, respectively, compared to the Al2O3/a-SiNx:H stack on the front side of the n-type solar cells due to the good anti-reflection and front side surface passivation.

  8. Coated electroactive materials

    Energy Technology Data Exchange (ETDEWEB)

    Amine, Khalil; Abouimrane, Ali

    2016-08-30

    A process includes suspending an electroactive material in a solvent, suspending or dissolving a carbon precursor in the solvent; and depositing the carbon precursor on the electroactive material to form a carbon-coated electroactive material. Compositions include a graphene-coated electroactive material prepared from a solution phase mixture or suspension of an electroactive material and graphene, graphene oxide, or a mixture thereof.

  9. Rock-hard coatings

    NARCIS (Netherlands)

    Muller, M.

    2007-01-01

    Aircraft jet engines have to be able to withstand infernal conditions. Extreme heat and bitter cold tax coatings to the limit. Materials expert Dr Ir. Wim Sloof fits atoms together to develop rock-hard coatings. The latest invention in this field is known as ceramic matrix composites. Sloof has sign

  10. Coating of graphene

    NARCIS (Netherlands)

    Schneider, G.F.; Dekker, C.

    2014-01-01

    The present invention is in the field of highly crystalline graphene and coating said graphene with a layer. Said graphene may have further structures, such as nanopores, nanogaps, and nanoribbons. The coated graphene can be used for biomolecular analysis and modification, such as DNA-sequencing, as

  11. Mechanically Invisible Polymer Coatings

    DEFF Research Database (Denmark)

    2014-01-01

    phase comprises particles, said particles comprising a filler material and an encapsulating coating of a second polymeric material, wherein the backbones of the first and second polymeric materials are the same. The composition may be used in electroactive polymers (EAPs) in order to obtain mechanically...... invisible polymer coatings....

  12. Chinese Decorative Coatings Market

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Growth prospects The Chinese market for decorative coatings, excluding non-architectural products such as industrial varnishes,marine paint and other industrially applied coatings, has been growing byaround 10% annually and was estimated to be worth Eurol.3 billion a year, with an annual per capita consumption of just less than 1 liter ofpaint.

  13. Nanostructured Protective Coatings

    Science.gov (United States)

    2006-01-01

    stresses induce strain fatigue with subsequent formation of cracks. Cracking in coatings leads to materials failure observed physically as spallation or...elevated temperatures. In this test a hole is drilled into the substrate before coating it. This allows a fixed amount of air to be trapped at the

  14. Optimization of Al2O3/SiNx stacked antireflection structures for N-type surfacepassivated crystalline silicon solar cells

    Institute of Scientific and Technical Information of China (English)

    Wu Dawei; Jia Rui; Ding Wuchang; Chen Chen; Wu Deqi; Chen Wei; Li Haofeng; Yue Huihui; Liu Xinyu

    2011-01-01

    In the case of N-type solar cells,the anti-reflection property,as one of the important factors to further improve the energy-conversion efficiency,has been optimized using a stacked Al2O3/SiNx layer.The effect of SiNx layer thickness on the surface reflection property was systematically studied in terms of both experimental and theoretical measurement.In the stacked Al2O3/SiNx layers,results demonstrated that the surface reflection property can be effectively optimized by adding a SiNx layer,leading to the improvement in the final photovoltaic characteristic of the N-type solar cells.

  15. Study by simulation of the SnO2 and ZnO anti-reflection layers in n-SiC/p-SiC solar cells

    Science.gov (United States)

    Zerfaoui, Hana; Dib, Djalel; Rahmani, Mohamed; Benyelloul, Kamel; Mebarkia, Chafia

    2016-07-01

    Recently, Two technologies of the photovoltaic cells are present today namely the cells crystalline (polycrystalline and monocrystalline) and the cell thin layers. The development of the solar cells requires a technological change of materials used in their manufacturing. The thin layers are parts of these materials and which announced their effectiveness and growth of output of the solar cell. The aim of this paper article is to the study and simulation of photovoltaic cells containing SiC materials. This material is have important having a part in the development of renewable energies. Based on the SCAPS (a Solar Cell Capacitance Simulator) simulation, the obtained results are Vco, Jsc, FF and the output energy of conversion of a solar cell n-SiC/p-SiC with different materials for the anti-reflecting layer ZnO and SnO2.with the SCAPS (a Solar Cell Capacitance Simulator) computer code in one dimension, the results obtained after optimization.

  16. Nano rods for coloured glasses obtained by hybrid sol-gel coating.

    Science.gov (United States)

    Veron, Olivier; Blondeau, Jean-Philippe; Moineau, Johanne; Aubert, Pierre-Henri; Vignolle, Caroline Andreazza; Banet, Philippe; Allam, Lévi

    2011-09-01

    Many new materials are now allowing new properties thanks to nanotechnology because this domain of physics gives possibilities to optimize targeted properties even if these materials react in very various influential parameters. Architectural, automotive, bone pathologies, environment, display applications are some concerned domains. The sol-gel process is a method allowing the realisation of coats at ambiant temperature, thus it is possible to realize Liquid Crystal Display (LCD), water-repellent coatings on privacy glass, antireflective coatings, hydrophobic or hydrophilic surfaces, bone tissue regeneration. In this study, the purpose is to show the thermal influence on a covered glass with a complex hybrid sol-gel solution. This coated glass is going to change color from red to orange under the heat influence. This color change effect comes from the evolution of various compounds organizations then/or from their loss during the degassing sequence. We show in spite of the complexity of the process that the responsible is mainly the organic dye. Thus the structure of the heated glass at 250 degrees C looks radically different than the heated one at 350 degrees C. SEM measurement allows to identify the surface compositions and to determine the elementary composition along the sample's cross section. TGA is used to justify a mass loss when samples are annealed. UV/Visible measurement is realized by two methods: in-line transmission to evaluate luminous flux and thus give colorimetric dot in the normalized CIE diagram and diffuse transmission to observe the size influence of the pigments. Infrared Reflectivity allows to evaluate the influence of species on the structure and to better target the nature of the lost compounds during annealing. TEM measurement proves that the obtained iron particles are nano rods for both samples.

  17. Phenol-formaldehyde intumescent coating composition and coating prepared therefrom

    Science.gov (United States)

    Salyer, Ival O. (Inventor); Fox, Bernard L. (Inventor)

    1986-01-01

    Intumescent coatings which form a thick, uniform, fine celled, low density foam upon exposure to a high intensity heat flux or flame are disclosed, the invention coatings comprise phenolic resin prepolymer containing a blowing agent and a nucleating agent; in the preferred embodiments the coatings also contains a silicone surfactant, the coatings are useful in thermal and fire protection systems.

  18. Fluorine Based Superhydrophobic Coatings

    Directory of Open Access Journals (Sweden)

    Jean-Denis Brassard

    2012-05-01

    Full Text Available Superhydrophobic coatings, inspired by nature, are an emerging technology. These water repellent coatings can be used as solutions for corrosion, biofouling and even water and air drag reduction applications. In this work, synthesis of monodispersive silica nanoparticles of ~120 nm diameter has been realized via Stöber process and further functionalized using fluoroalkylsilane (FAS-17 molecules to incorporate the fluorinated groups with the silica nanoparticles in an ethanolic solution. The synthesized fluorinated silica nanoparticles have been spin coated on flat aluminum alloy, silicon and glass substrates. Functionalization of silica nanoparticles with fluorinated groups has been confirmed by Fourier Transform Infrared spectroscopy (FTIR by showing the presence of C-F and Si-O-Si bonds. The water contact angles and surface roughness increase with the number of spin-coated thin films layers. The critical size of ~119 nm renders aluminum surface superhydrophobic with three layers of coating using as-prepared nanoparticle suspended solution. On the other hand, seven layers are required for a 50 vol.% diluted solution to achieve superhydrophobicity. In both the cases, water contact angles were more than 150°, contact angle hysteresis was less than 2° having a critical roughness value of ~0.700 µm. The fluorinated silica nanoparticle coated surfaces are also transparent and can be used as paint additives to obtain transparent coatings.

  19. Advanced thermal barrier coating systems

    Science.gov (United States)

    Dorfman, M. R.; Reardon, J. D.

    1985-01-01

    Current state-of-the-art thermal barrier coating (TBC) systems consist of partially stabilized zirconia coatings plasma sprayed over a MCrAlY bond coat. Although these systems have excellent thermal shock properties, they have shown themselves to be deficient for a number of diesel and aircraft applications. Two ternary ceramic plasma coatings are discussed with respect to their possible use in TBC systems. Zirconia-ceria-yttria (ZCY) coatings were developed with low thermal conductivities, good thermal shock resistance and improved resistance to vanadium containing environments, when compared to the baseline yttria stabilized zirconia (YSZ) coatings. In addition, dense zirconia-titania-yttria (ZTY) coatings were developed with particle erosion resistance exceeding conventional stabilized zirconia coatings. Both coatings were evaluated in conjunction with a NiCr-Al-Co-Y2O3 bond coat. Also, multilayer or hybrid coatings consisting of the bond coat with subsequent coatings of zirconia-ceria-yttria and zirconia-titania-yttria were evaluated. These coatings combine the enhanced performance characteristics of ZCY with the improved erosion resistance of ZTY coatings. Improvement in the erosion resistance of the TBC system should result in a more consistent delta T gradient during service. Economically, this may also translate into increased component life simply because the coating lasts longer.

  20. Aluminum phosphate coatings

    Science.gov (United States)

    Sambasivan, Sankar; Steiner, Kimberly A.; Rangan, Krishnaswamy K.

    2007-12-25

    Aluminophosphate compounds and compositions as can be used for substrate or composite films and coating to provide or enhance, without limitation, planarization, anti-biofouling and/or anti-microbial properties.

  1. Inorganic Coatings Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The inorganic Coatings Lab provides expertise to Navy and Joint Service platforms acquisition IPTs to aid in materials and processing choices which balance up-front...

  2. Friction surfaced Stellite6 coatings

    Energy Technology Data Exchange (ETDEWEB)

    Rao, K. Prasad; Damodaram, R. [Department of Metallurgical and Materials Engineering - Indian Institute of Technology Madras, Chennai 600 036 (India); Rafi, H. Khalid, E-mail: khalidrafi@gmail.com [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600 036 (India); Ram, G.D. Janaki [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600 036 (India); Reddy, G. Madhusudhan [Metal Joining Group, Defence Metallurgical Research Laboratory (DMRL) Kanchanbagh, Hyderabad 500 058 (India); Nagalakshmi, R. [Welding Research Institute, Bharat Heavy Electricals Limited, Tiruchirappalli 620 014 (India)

    2012-08-15

    Solid state Stellite6 coatings were deposited on steel substrate by friction surfacing and compared with Stellite6 cast rod and coatings deposited by gas tungsten arc and plasma transferred arc welding processes. Friction surfaced coatings exhibited finer and uniformly distributed carbides and were characterized by the absence of solidification structure and compositional homogeneity compared to cast rod, gas tungsten arc and plasma transferred coatings. Friction surfaced coating showed relatively higher hardness. X-ray diffraction of samples showed only face centered cubic Co peaks while cold worked coating showed hexagonally close packed Co also. - Highlights: Black-Right-Pointing-Pointer Stellite6 used as coating material for friction surfacing. Black-Right-Pointing-Pointer Friction surfaced (FS) coatings compared with casting, GTA and PTA processes. Black-Right-Pointing-Pointer Finer and uniformly distributed carbides in friction surfaced coatings. Black-Right-Pointing-Pointer Absence of melting results compositional homogeneity in FS Stellite6 coatings.

  3. Nanostructured Superhydrophobic Coatings

    Energy Technology Data Exchange (ETDEWEB)

    None

    2009-03-01

    This factsheet describes a research project that deals with the nanostructured superhydrophobic (SH) powders developed at ORNL. This project seeks to (1) improve powder quality; (2) identify binders for plastics, fiberglass, metal (steel being the first priority), wood, and other products such as rubber and shingles; (3) test the coated product for coating quality and durability under operating conditions; and (4) application testing and production of powders in quantity.

  4. Spin coating apparatus

    Science.gov (United States)

    Torczynski, John R.

    2000-01-01

    A spin coating apparatus requires less cleanroom air flow than prior spin coating apparatus to minimize cleanroom contamination. A shaped exhaust duct from the spin coater maintains process quality while requiring reduced cleanroom air flow. The exhaust duct can decrease in cross section as it extends from the wafer, minimizing eddy formation. The exhaust duct can conform to entrainment streamlines to minimize eddy formation and reduce interprocess contamination at minimal cleanroom air flow rates.

  5. Coated 4340 Steel

    Science.gov (United States)

    2013-08-26

    alternative coatings qualified to MIL-PRE-23377 Class N and an electroplated zinc - nickel alloy passivated with a trivalent chromium solution which is...effect of a non-chromate primer and zinc - nickel plating with non-chromate passivation as alternatives to the chromate primer and cadmium plating with...NAWCADPAX/TR-2013/252 COATED 4340 STEEL by E. U. Lee C. Lei M. Stanley B. Pregger C. Matzdorf 26 August 2013

  6. Residual stresses within sprayed coatings

    Institute of Scientific and Technical Information of China (English)

    JIANG Yi; XU Bin-shi; WANG Hai-dou

    2005-01-01

    Some important developments of residual stress researches for coating-based systems were studied. The following topics were included the sources of residual stresses in coatings: error analysis of Stoney's equation in the curvature method used for the measurement of coating residual stress, the modeling of residual stress and some analytical models for predicting the residual stresses in coatings. These topics should provide some important insights for the fail-safe design of the coating-based systems.

  7. Hydroxyapatite coatings for biomedical applications

    CERN Document Server

    Zhang, Sam

    2013-01-01

    Hydroxyapatite coatings are of great importance in the biological and biomedical coatings fields, especially in the current era of nanotechnology and bioapplications. With a bonelike structure that promotes osseointegration, hydroxyapatite coating can be applied to otherwise bioinactive implants to make their surface bioactive, thus achieving faster healing and recovery. In addition to applications in orthopedic and dental implants, this coating can also be used in drug delivery. Hydroxyapatite Coatings for Biomedical Applications explores developments in the processing and property characteri

  8. Biocompatibility of Niobium Coatings

    Directory of Open Access Journals (Sweden)

    René Olivares-Navarrete

    2011-09-01

    Full Text Available Niobium coatings deposited by magnetron sputtering were evaluated as a possible surface modification for stainless steel (SS substrates in biomedical implants. The Nb coatings were deposited on 15 mm diameter stainless steel substrates having an average surface roughness of 2 mm. To evaluate the biocompatibility of the coatings three different in vitro tests, using human alveolar bone derived cells, were performed: cellular adhesion, proliferation and viability. Stainless steel substrates and tissue culture plastic were also studied, in order to give comparative information. No toxic response was observed for any of the surfaces, indicating that the Nb coatings act as a biocompatible, bioinert material. Cell morphology was also studied by immune-fluorescence and the results confirmed the healthy state of the cells on the Nb surface. X-ray diffraction analysis of the coating shows that the film is polycrystalline with a body centered cubic structure. The surface composition and corrosion resistance of both the substrate and the Nb coating were also studied by X-ray photoelectron spectroscopy and potentiodynamic tests. Water contact angle measurements showed that the Nb surface is more hydrophobic than the SS substrate.

  9. Microstructural characterization of hydrophobic Ti{sub 1-x}Al{sub x}N coatings with moth-eye-like surface morphology

    Energy Technology Data Exchange (ETDEWEB)

    Godinho, V., E-mail: godinho@icmse.csic.es [Instituto de Ciencia de Materiales de Sevilla CSIC-Uni. Sevilla, Av. Americo Vespucio 49, 41092 Sevilla (Spain); Lopez-Santos, C. [NAmur Research Institute for LIfe Sciences (NARILIS), Research Center in Physics of Matter and Radiation (PMR), University of Namur -FUNDP, 61 Rue de Bruxelles, 5000 Namur (Belgium); Rojas, T.C.; Philippon, D.; Jimenez de Haro, M.C. [Instituto de Ciencia de Materiales de Sevilla CSIC-Uni. Sevilla, Av. Americo Vespucio 49, 41092 Sevilla (Spain); Lucas, S. [NAmur Research Institute for LIfe Sciences (NARILIS), Research Center in Physics of Matter and Radiation (PMR), University of Namur - FUNDP, 61 Rue de Bruxelles, 5000 Namur (Belgium); Fernandez, A. [Instituto de Ciencia de Materiales de Sevilla CSIC-Uni. Sevilla, Av. Americo Vespucio 49, 41092 Sevilla (Spain)

    2012-09-25

    Highlights: Black-Right-Pointing-Pointer Moth-eye-like structures were obtained by changing the power supplied to the targets at a constant N{sub 2} pressure. Black-Right-Pointing-Pointer The antireflecting properties and hydrophobicity of the coatings are discussed. Black-Right-Pointing-Pointer HREM and related techniques revealed the formation of meso- and nano-columns and different degree of open porosity. - Abstract: Ti{sub 1-x}Al{sub x}N thin films with different Al content were deposited by magnetron sputtering. The combination of electron energy loss spectroscopy (EELS) and energy dispersive spectroscopy (EDS) was used to evaluate the composition of the coatings. The effect of Al content on the morphology and properties of the coatings was investigated. High resolution electron microscopy and related techniques revealed the formation of a pillared moth-eye-like nanostructure with variable size and distribution of meso- and nano-columns and different degree of open porosity that depends on the Al content on the coating. For low Al content (x {<=} 0.21) c-(Ti,Al)N highly porous columns ending in a sharp pyramidal shape present low reflectivity and high hydrophobicity. While the precipitation of h-AlN phase at the column boundaries for x = 0.71 suppresses the c-(Ti,Al)N columnar growth and produces a smother surface, with higher reflectivity and less hydrophobic character.

  10. Controlled Thermal Expansion Coat for Thermal Barrier Coatings

    Science.gov (United States)

    Brindley, William J. (Inventor); Miller, Robert A. (Inventor); Aikin, Beverly J. M. (Inventor)

    1999-01-01

    A improved thermal barrier coating and method for producing and applying such is disclosed herein. The thermal barrier coating includes a high temperature substrate, a first bond coat layer applied to the substrate of MCrAlX, and a second bond coat layer of MCrAlX with particles of a particulate dispersed throughout the MCrAlX and the preferred particulate is Al2O3. The particles of the particulate dispersed throughout the second bond coat layer preferably have a diameter of less then the height of the peaks of the second bond coat layer, or a diameter of less than 5 microns. The method of producing the second bond coat layer may either include the steps of mechanical alloying of particles throughout the second bond coat layer, attrition milling the particles of the particulate throughout the second bond coat layer, or using electrophoresis to disperse the particles throughout the second bond coat layer. In the preferred embodiment of the invention, the first bond coat layer is applied to the substrate, and then the second bond coat layer is thermally sprayed onto the first bond coat layer. Further, in a preferred embodiment of die invention, a ceramic insulating layer covers the second bond coat layer.

  11. Optimisation of a sol-gel synthesis route for the preparation of MgF2 particles for a large scale coating process.

    Science.gov (United States)

    Scheurell, K; Noack, J; König, R; Hegmann, J; Jahn, R; Hofmann, Th; Löbmann, P; Lintner, B; Garcia-Juan, P; Eicher, J; Kemnitz, E

    2015-12-07

    A synthesis route for the preparation of optically transparent magnesium fluoride sols using magnesium acetate tetrahydrate as precursor is described. The obtained magnesium fluoride sols are stable for several months and can be applied for antireflective coatings on glass substrates. Reaction parameters in the course of sol synthesis are described in detail. Thus, properties of the precursor materials play a crucial role in the formation of the desired magnesium fluoride nanoparticles, this is drying the precursor has to be performed under defined mild conditions, re-solvation of the dried precursor has to be avoided and addition of water to the final sol-system has to be controlled strictly. Important properties of the magnesium fluoride sols like viscosity, particle size distribution, and structural information are presented as well.

  12. Effect of Coated PHB on Properties of Abradable Seal Coating

    Institute of Scientific and Technical Information of China (English)

    CHENG Xudong; XIANG Hongyu; YE Weiping; MENG Xiaoming; MIN Jie; LIU Minzhi; ZHANG Pu; LU Wei

    2014-01-01

    As pore-forming materials, the coated poly-p-hydroxybenzoate(short for PHB) and h-BN can be applied in the preparation of abradable seal coatings at high temperature. The characteristics of coating such as morphology, thermal stability and composition were studied by SEM, EDS and FTIR. The results show that the modified PHB will change the remained carbon amount, porosity and pore morphology of the coating, which can affect the properties of coatings. If the pore is small enough in uniform distribution, the coating with 5 MPa bond strength, 30-55 HR45Y superficial hardness and certain of carbon can be suitable to well abradability.

  13. Coatings for directional eutectics

    Science.gov (United States)

    Rairden, J. R.; Jackson, M. R.

    1976-01-01

    Coatings developed to provide oxidation protection for the directionally-solidified eutectic alloy NiTaC-B (4.4 weight percent Cr) were evaluated. Of seven Co-, Fe- and Ni-base coatings that were initially investigated, best resistance to cyclic oxidation was demonstrated by duplex coatings fabricated by depositing a layer of NiCrAl(Y) by vacuum evaporation from an electron beam source followed by deposition of an Al overlayer using the pack cementation process. It was found that addition of carbon to the coating alloy substantially eliminated the problem of fiber denudation in TaC-type eutectic alloys. Burner rig cycled NiTaC-B samples coated with Ni-20Cr-5Al-0.1C-0.1Y+Al and rupture-tested at 1100 deg C performed as well as or better than uncoated, vacuum cycled and air-tested NiTaC-13; however, a slight degradation with respect to uncoated material was noted in air-stress rupture tests at 870 deg C for both cycled and uncycled samples.

  14. Based Adaptive Nanocomposite Coatings

    Science.gov (United States)

    Ramazani, M.; Ashrafizadeh, F.; Mozaffarinia, R.

    2014-08-01

    A promising Ni(Al)-Cr2O3-Ag-CNT-WS2 self-lubricating wear-resistant coating was deposited via atmospheric plasma spray of Ni(Al), nano Cr2O3, nano silver and nano WS2 powders, and CNTs. Feedstock powders with various compositions prepared by spray drying were plasma sprayed onto carbon steel substrates. The tribological properties of coatings were tested by a high temperature tribometer in a dry environment from room temperature to 400 °C, and in a natural humid environment at room temperature. It was found that all nanocomposite coatings have better frictional behavior compared with pure Ni(Al) and Ni(Al)-Cr2O3 coatings; the specimen containing aproximately 7 vol.% Ag, CNT, and WS2 had the best frictional performance. The average room temperature friction coefficient of this coating was 0.36 in humid atmosphere, 0.32 in dry atmosphere, and about 0.3 at high temperature.

  15. High Performance Optical Coatings Utilizing Tailored Refractive Index Nanoporous Thin Films

    Science.gov (United States)

    Poxson, David J.

    Refractive index is perhaps the most important quantity in optics. It is particularly relevant in the field of optical coatings, where the refractive index appears in virtually every optics equation as a figure of merit. Recently it has been demonstrated through control of the deposition angle during oblique-angle electron-beam deposition, nanoporous films of virtually any desired porosity may be accurately deposited. As the porosity of a nanoporous film directly relates to its effective refractive index, the refractive index value of a film may be tailored to any value between that of the bulk material and close to that of air. These two characteristics, namely; (i) tailored-refractive index and (ii) very low-refractive index values close to that of air, offer significant advantages in the design and optical performance in all optical coating applications. In this dissertation we explore optical coating applications whose performance can be greatly enhanced by utilization of a tailored- and low-refractive index nanoporous material system. One such important application is in the design and fabrication of broadband, omnidirectional antireflection (AR) coatings on solar cell devices. To harness the full spectrum of solar energy, Fresnel reflections at the surface of a photovoltaic cell must be reduced as much as possible over the relevant solar wavelength range and over a wide range of incident angles. However, the development of AR coatings embodying omni-directionality over a wide range of wavelengths is challenging. By utilizing the tailored- and low-refractive index properties of the nanoporous material system, in conjunction with a computational genetic algorithm and a predictive quantitative model for the porosity of such nanoporous films, truly optimized AR coatings can be designed and fabricated on solar cells. Here we show that these optimized AR structures demonstrate significant improvement to overall device efficiency. Traditionally, nanoporous films

  16. Tribology and coatings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-01

    The future use of fuel-efficient, low-emission, advanced transportation systems (for example, those using low-heat-rejection diesel engines or advanced gas turbines) presents new challenges to tribologists and materials scientists. High service temperatures, corrosive environments, and extreme contact pressures are among the concerns that make necessary new tribological designs, novel materials, and effective lubrication concepts. Argonne is working on methods to reduce friction, wear and corrosion, such as soft metal coatings on ceramics, layered compounds, diamond coatings, and hard surfaces.

  17. HA-Coated Implant

    DEFF Research Database (Denmark)

    Daugaard, Henrik; Søballe, Kjeld; Bechtold, Joan E

    2014-01-01

    The goal of osseointegration of orthopedic and dental implants is the rapid achievement of a mechanically stable and long lasting fixation between living bone and the implant surface. In total joint replacements of cementless designs, coatings of calcium phosphates were introduced as a means...... of improving the fixation of implants. Of these, hydroxyapatite (HA) is the most widely used and most extensively investigated. HA is highly osseoconductive, and the positive effect is well documented in both basic and long-term clinical research [1–6]. This chapter describes experimental and clinical studies...... evaluating bone-implant fixation with HA coatings....

  18. Bioceramics for implant coatings

    Directory of Open Access Journals (Sweden)

    Allison A Campbell

    2003-11-01

    Early research in this field focused on understanding the biomechanical properties of metal implants, but recent work has turned toward improving the biological properties of these devices. This has led to the introduction of calcium phosphate (CaP bioceramics as a bioactive interface between the bulk metal impart and the surrounding tissue. The first CaP coatings were produced via vapor phase processes, but more recently solution-based and biomimetic methods have emerged. While each approach has its own intrinsic materials and biological properties, in general CaP coatings promise to improve implant biocompatibility and ultimately implant longevity.

  19. Advanced Coating Removal Techniques

    Science.gov (United States)

    Seibert, Jon

    2006-01-01

    An important step in the repair and protection against corrosion damage is the safe removal of the oxidation and protective coatings without further damaging the integrity of the substrate. Two such methods that are proving to be safe and effective in this task are liquid nitrogen and laser removal operations. Laser technology used for the removal of protective coatings is currently being researched and implemented in various areas of the aerospace industry. Delivering thousands of focused energy pulses, the laser ablates the coating surface by heating and dissolving the material applied to the substrate. The metal substrate will reflect the laser and redirect the energy to any remaining protective coating, thus preventing any collateral damage the substrate may suffer throughout the process. Liquid nitrogen jets are comparable to blasting with an ultra high-pressure water jet but without the residual liquid that requires collection and removal .As the liquid nitrogen reaches the surface it is transformed into gaseous nitrogen and reenters the atmosphere without any contamination to surrounding hardware. These innovative technologies simplify corrosion repair by eliminating hazardous chemicals and repetitive manual labor from the coating removal process. One very significant advantage is the reduction of particulate contamination exposure to personnel. With the removal of coatings adjacent to sensitive flight hardware, a benefit of each technique for the space program is that no contamination such as beads, water, or sanding residue is left behind when the job is finished. One primary concern is the safe removal of coatings from thin aluminum honeycomb face sheet. NASA recently conducted thermal testing on liquid nitrogen systems and found that no damage occurred on 1/6", aluminum substrates. Wright Patterson Air Force Base in conjunction with Boeing and NASA is currently testing the laser remOval technique for process qualification. Other applications of liquid

  20. Active Packaging Coatings

    Directory of Open Access Journals (Sweden)

    Luis J. Bastarrachea

    2015-11-01

    Full Text Available Active food packaging involves the packaging of foods with materials that provide an enhanced functionality, such as antimicrobial, antioxidant or biocatalytic functions. This can be achieved through the incorporation of active compounds into the matrix of the commonly used packaging materials, or by the application of coatings with the corresponding functionality through surface modification. The latter option offers the advantage of preserving the packaging materials’ bulk properties nearly intact. Herein, different coating technologies like embedding for controlled release, immobilization, layer-by-layer deposition, and photografting are explained and their potential application for active food packaging is explored and discussed.

  1. Preparation of hydrophobic coatings

    Science.gov (United States)

    Branson, Eric D.; Shah, Pratik B.; Singh, Seema; Brinker, C. Jeffrey

    2009-02-03

    A method for preparing a hydrophobic coating by preparing a precursor sol comprising a metal alkoxide, a solvent, a basic catalyst, a fluoroalkyl compound and water, depositing the precursor sol as a film onto a surface, such as a substrate or a pipe, heating, the film and exposing the film to a hydrophobic silane compound to form a hydrophobic coating with a contact angle greater than approximately 150.degree.. The contact angle of the film can be controlled by exposure to ultraviolet radiation to reduce the contact angle and subsequent exposure to a hydrophobic silane compound to increase the contact angle.

  2. Methods and means for coating paper by film coating

    NARCIS (Netherlands)

    van der Maarel, Marc; Ter Veer, Arend Berend Cornelis; Vrieling-Smit, Annet; Delnoye, Pierre

    2015-01-01

    This invention relates to the field of paper coating, more in particular to means and methods for providing paper with at least one layer of pigment using film coating to obtain a well printable surface. Provided is a method for preparing coated paper comprising the steps of: a) providing a pigmente

  3. Optical coatings for fiber lasers

    Institute of Scientific and Technical Information of China (English)

    HONG Dong-mei; ZHU Zhen; YUE Wei

    2005-01-01

    Fiber laser is the future development direction for the high energy lasers. This paper describs two kinds of optical coatings for fiber laser, including long and short wave pass filters. The one characteristic of fiber laser coatings lies in that coatings should separate two closely wavelength light including laser pump wavelength (980 nm) and laser irradiation wavelength(1 050~1 100 nm). At the same time, the coatings should have high laser damage threshold.

  4. Tribological characterization of selected hard coatings

    OpenAIRE

    Karlsson, Patrik

    2009-01-01

    Hard coatings are often used for protection of tool surfaces due to coating properties like low friction and high wear resistance. Even though many of the hard coatings have been tested for wear, it is important to try new wear test setups to fully understand tribological mechanisms and the potential of hard coatings. Few experiments have been performed with dual-coated systems where the sliding contact surfaces are coated with the same, or different, hard coating. The dual-coated system coul...

  5. Chitin-based coatings

    OpenAIRE

    1995-01-01

    A chitosan starting material is combined with a dilute organic acid to produce a chitosonium ion complex. The chitosonium ion complex is then cast, sprayed, extruded, or otherwise processed to produce filaments, coatings, fibers, or the like. Heat is then used to convert the chitosonium ion complex into a N-(C.sub.1-30)acyl glucose amine polymer.

  6. ATHENA optimized coating design

    DEFF Research Database (Denmark)

    Ferreira, Desiree Della Monica; Christensen, Finn Erland; Jakobsen, Anders Clemen

    2012-01-01

    The optimization of coating design for the ATHENA mission si described and the possibility of increasing the telescope effective area in the range between 0.1 and 10 keV is investigated. An independent computation of the on-axis effective area based on the mirror design of ATHENA is performed in ...

  7. ZnO nanorod arrays and direct wire bonding on GaN surfaces for rapid fabrication of antireflective, high-temperature ultraviolet sensors

    Science.gov (United States)

    So, Hongyun; Senesky, Debbie G.

    2016-11-01

    Rapid, cost-effective, and simple fabrication/packaging of microscale gallium nitride (GaN) ultraviolet (UV) sensors are demonstrated using zinc oxide nanorod arrays (ZnO NRAs) as an antireflective layer and direct bonding of aluminum wires to the GaN surface. The presence of the ZnO NRAs on the GaN surface significantly reduced the reflectance to less than 1% in the UV and 4% in the visible light region. As a result, the devices fabricated with ZnO NRAs and mechanically stable aluminum bonding wires (pull strength of 3-5 gf) showed higher sensitivity (136.3% at room temperature and 148.2% increase at 250 °C) when compared with devices with bare (uncoated) GaN surfaces. In addition, the devices demonstrated reliable operation at high temperatures up to 300 °C, supporting the feasibility of simple and cost-effective UV sensors operating with higher sensitivity in high-temperature conditions, such as in combustion, downhole, and space exploration applications.

  8. Large-area one-step assembly of three-dimensional porous metal micro/nanocages by ethanol-assisted femtosecond laser irradiation for enhanced antireflection and hydrophobicity.

    Science.gov (United States)

    Li, Guoqiang; Li, Jiawen; Zhang, Chenchu; Hu, Yanlei; Li, Xiaohong; Chu, Jiaru; Huang, Wenhao; Wu, Dong

    2015-01-14

    The capability to realize 2D-3D controllable metallic micro/nanostructures is of key importance for various fields such as plasmonics, electronics, bioscience, and chemistry due to unique properties such as electromagnetic field enhancement, catalysis, photoemission, and conductivity. However, most of the present techniques are limited to low-dimension (1D-2D), small area, or single function. Here we report the assembly of self-organized three-dimensional (3D) porous metal micro/nanocages arrays on nickel surface by ethanol-assisted femtosecond laser irradiation. The underlying formation mechanism was investigated by a series of femtosecond laser irradiation under exposure time from 5 to 30 ms. We also demonstrate the ability to control the size of micro/nanocage arrays from 0.8 to 2 μm by different laser pulse energy. This method features rapidness (∼10 min), simplicity (one-step process), and ease of large-area (4 cm(2) or more) fabrication. The 3D cagelike micro/nanostructures exhibit not only improved antireflection from 80% to 7% but also enhanced hydrophobicity from 98.5° to 142° without surface modification. This simple technique for 3D large-area controllable metal microstructures will find great potential applications in optoelectronics, physics, and chemistry.

  9. Simulation and Experimental Study on Anti-reflection Characteristics of Nano-patterned Si Structures for Si Quantum Dot-Based Light-Emitting Devices.

    Science.gov (United States)

    Shao, Wenyi; Lu, Peng; Li, Wei; Xu, Jun; Xu, Ling; Chen, Kunji

    2016-12-01

    Surface-textured structure is currently an interesting topic since it can efficiently reduce the optical losses in advanced optoelectronic devices via light management. In this work, we built a model in finite-difference time-domain (FDTD) solutions by setting the simulation parameters based on the morphology of the Si nanostructures and compared with the experimental results in order to study the anti-reflection behaviors of the present nano-patterned structures. It is found that the reflectance is gradually reduced by increasing the depth of Si nanostructures which is in well agreement with the experimental observations. The reflectance can be lower than 10 % in the light range from 400 to 850 nm for Si nano-patterned structures with a depth of 150 nm despite the quite low aspect ratio, which can be understood as the formation of gradually changed index layer and the scattering effect of Si nano-patterned structures. By depositing the Si quantum dots/SiO2 multilayers on nano-patterned Si substrate, the reflectance can be further suppressed and the luminescence intensity centered at 820 nm from Si quantum dots is enhanced by 6.6-fold compared with that of flat one, which can be attributed to the improved light extraction efficiency. However, the further etch time causes the reduction of luminescence intensity from Si quantum dots which may ascribe to the serious surface recombination of carriers.

  10. Fabrication of Anti-reflecting Si Nano-structures with Low Asp ect Ratio by Nano-sphere Litho-graphy Technique

    Institute of Scientific and Technical Information of China (English)

    Shenghua Sun; Peng Lu; Jun Xu; Ling Xu; Kunji Chen; Qimin Wang; Yuhua Zuo

    2013-01-01

    Nano-structured photon management is currently an interesting topic since it can enhance the optical absorption and reduce the surface reflection which will improve the performance of many kinds of optoelectronic devices, such as Si-based solar cells and light emitting diodes. Here, we report the fabrication of periodically nano-patterned Si structures by using polystyrene nano-sphere lithography technique. By changing the diameter of nano-spheres and the dry etching parameters, such as etching time and etching power, the morphologies of formed Si nano-structures can be well controlled as revealed by atomic force microscopy. A good broadband antireflection property has been achieved for the formed periodically nano-patterned Si structures though they have the low aspect ratio (<0.53). The reflection can be significantly reduced compared with that of flat Si substrate in a wavelength range from 400 nm to 1200 nm. The weighted mean reflection under the AM1.5 solar spectrum irradiation can be as low as 3.92% and the corresponding optical absorption is significantly improved, which indicates that the present Si periodic nano-structures can be used in Si-based thin film solar cells.

  11. Numerical design of thin perovskite solar cell with fiber array-based anti-reflection front electrode for light-trapping enhancement

    Science.gov (United States)

    Khang Nguyen, Truong; Dang, Phuc Toan; Le, Khai Q.

    2016-12-01

    Perovskite has recently drawn substantial interest in photovoltaic research owing to its unique potentials of low cost fabrication and high power conversion efficiency. In this paper, a thin solar cells made of perovskite photoactive layer is introduced. The proposed perovskite-based solar cell with atop antireflection front electrode (p-ARFE) made of fiber arrays is calibrated to generate lensing/anti-reflecting effects and thus resulting in improved absorption efficiency. Theoretical and numerical results have demonstrated that the overall integrated AM1.5 G absorption in an optimal configuration yields a maximum short circuit current density of 20.2 mA cm-2 and an enhancement up to 6.3% compared to its flat solar cell counterpart with a same perovskite thickness of 200 nm. The proposed p-ARFE solar cell also presents a relative broadband absorption characteristic with zero reflection at multiple visible frequencies, i.e., 360-750 nm, thus more benefiting associated with next-generation perovskite-based solar cell applications.

  12. Silicon-on-ceramic coating process. Silicon sheet growth development for the Large-Area Silicon Sheet and Cell Development Tasks of the Low-Cost Silicon Solar Array Project. Quarterly report No. 8, December 28, 1977--March 28, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, P.W. Zook, J.D.; Heaps, J D; Maclolek, R B; Koepke, B; Butter, C D; Schult, S B

    1978-04-20

    A research program to investigate the technical and economic feasibility of producing solar-cell-quality sheet silicon by coating inexpensive ceramic substrates with a thin layer of polycrystalline silicon is described. The coating methods to be developed are directed toward a minimum-cost process for producing solar cells with a terrestrial conversion efficiency of 12 percent or greater. By applying a graphite coating to one face of a ceramic substrate, molten silicon can be caused to wet only that graphite-coated face and produce uniform thin layers of large-grain polycrystalline silicon; thus, only a minimal quantity of silicon is consumed. A dip-coating method for putting silicon on ceramic (SOC) has been shown to produce solar-cell-quality sheet silicon. This method and a continuous coating process also being investigated have excellent scale-up potential which offers an outstanding cost-effective way to manufacture large-area solar cells. A variety of ceramic materials have been dip-coated with silicon. The investigation has shown that mullite substrates containing an excess of SiO/sub 2/ best match the thermal expansion coefficient of silicon and hence produce the best SOC layers. With such substrates, smooth and uniform silicon layers 25 cm/sup 2/ in area have been achieved with single-crystal grains as large as 4 mm in width and several cm in length. Solar cells with areas from 1 to 10 cm/sup 2/ have been fabricated from material withas-grown surface. Recently, an antireflection (AR) coating has been applied to SOC cells. Conversion efficiencies greater than 9% have been achieved without optimizing series resistance characteristics. Such cells typically have open-circuit voltages and short-circuit current densities of 0.51 V and 20 mA/cm/sup 2/, respectively.

  13. Increasing The Efficiency of Silicon Solar Cells via an Anti-reflecting Nano-porous Surface Layer

    Science.gov (United States)

    Coskuner, Ahmet; Gokce, Aisha; Altunay, Omer; Skarlatos, Yani; Ozatay, Ozhan

    2015-03-01

    Electrochemical etching of silicon in a controlled environment results in a porous surface that has many application areas from drug delivery to optoluminescent devices. There is vast interest in implementing porous silicon in silicon solar cells to increase light absorption and therefore the efficiency. Here we demonstrate successful formation of a nano-porous surface on mono-crystalline Si wafers as well as doped Si solar cells. Our results show that pre-cleaning and post-drying is crucial to acquire a smooth, non-cracked topography. We also find that under similar conditions, smaller pores in a denser arrangement and with shorter depths form in p-n junction type Si wafers compared to n-type or p-type Si. In ITO coated porous Si solar cells with Al back contacts, the measured efficiency increase is almost 50% of those without a porous surface. This is a promising result to further enhance the performance of Si solar cell devices.

  14. Fabrication of a Ni nano-imprint stamp for an anti-reflective layer using an anodic aluminum oxide template.

    Science.gov (United States)

    Park, Eun-Mi; Lim, Seung-Kyu; Ra, Senug-Hyun; Suh, Su-Jung

    2013-11-01

    Aluminum anodizing can alter pore diameter, density distribution, periodicity and layer thickness in a controlled way. Because of this property, porous type anodic aluminum oxide (AAO) was used as a template for nano-structure fabrication. The alumina layer generated at a constant voltage increased the pore size from 120 nm to 205 nm according to an increasing process time from 60 min to 150 min. The resulting fabricated AAO templates had pore diameters at or less than 200 nm. Ni was sputtered as a conductive layer onto this AAO template and electroplated using DC and pulse power. Comparing these Ni stamps, those generated from electroplating using on/reverse/off pulsing had an ordered pillar array and maintained the AAO template morphology. This stamp was used for nano-imprinting on UV curable resin coated glass wafer. Surface observations via electron microscopy showed that the nano-imprinted patterned had the same shape as the AAO template. A soft mold was subsequently fabricated and nano-imprinted to form a moth-eye structure on the glass wafer. An analysis of the substrate transmittance using UV-VIS/NIR spectroscopy showed that the transmittance of the substrate with the moth-eye structure was 5% greater that the non-patterned substrate.

  15. 纳米ZnO-SiO2自清洁增透薄膜的制备及其性能∗%Preparation and characterization of self-cleaning and anti-reflection ZnO-SiO2 nanometric films

    Institute of Scientific and Technical Information of China (English)

    郭昭龙; 赵海新; 赵卫

    2016-01-01

    Unlike the general anti-reflection and self-cleaning film such as SiO2 and TiO2-SiO2, the ZnO-SiO2 nanometric film used as a substrate of excellent transparency in visible region and effective photo-catalytic self-cleaning under UV illumination is seldom studied in the application as a substrate; however, it has a lot of advantages including high transmittance and low refractivity. In this paper, a self-cleaning and anti-reflection ZnO-SiO2 nanometric film is successfully fabricated by using a sol-gel dip-coating method. The morphology, crystal structure, surface microstructure and light transmittance of the obtained products are characterized by techniques such as TEM, SAD, XRD, SEM, DTA and UV-vis. Photo-catalytic degradation of the methylene blue (MB) in aqueous solution is used as probe reaction to evaluate the photo-catalytic activity of ZnO-SiO2 nanometric film. The TEM images reveal that the as-prepared ZnO nanoparticles are spherical grains with diameters of 12–20 nm, the average grain diameter is about 14.51 nm. ZnO nanoparticles obtained are of hexagonal wurtzite structure revealed by XRD pattern and there exist no other diffraction peaks. Furthermore, the SAD results show that ZnO microstructurs have good crystallinity. In addition, the ZnO grain size is about 14.41 nm by using the Scherrer formula calculation, which is consistent with the TEM results by the Gauss simulation. The UV-vis spectra reveal that the ultraviolet characteristic absorption peak of ZnO-SiO2 composite films is located at 368 nm and 375 nm after annealing at different temperatures such as 300 ◦C and 450 ◦C, corresponding to the band gaps of 3.37 eV and 3.31 eV, respectively. It is highly consistent with that obtained from pure ZnO nanoparticles. Increasing the annealing temperature results in a lower refractive index and the increases of the porosity in of the ZnO-SiO2 composite films. It has a uniformly refractive index value about 1.23–1.25 and a high porosity value about

  16. Thermoplastic coating of carbon fibers

    Science.gov (United States)

    Edie, D. D.; Lickfield, G. C.; Drews, M. J.; Ellison, M. S.; Gantt, B. W.

    1989-01-01

    A process is being developed which evenly coats individual carbon fibers with thermoplastic polymers. In this novel, continuous coating process, the fiber tow bundle is first spread cover a series of convex rollers and then evenly coated with a fine powder of thermoplastic matrix polymer. Next, the fiber is heated internally by passing direct current through the powder coated fiber. The direct current is controlled to allow the carbon fiber temperature to slightly exceed the flow temperature of the matrix polymer. Analysis of the thermoplastic coated carbon fiber tows produced using this continuous process indicates that 30 to 70 vol pct fiber prepregs can be obtained.

  17. Coatings for improved corrosion resistance

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, K.

    1992-05-01

    Several coating approaches are being developed to resist attack in coal-fired environments and thereby minimize corrosion of underlying substrate alloys and extend the time for onset of breakaway corrosion. In general, coating systems can be classified as either diffusion or overlay type, which are distinguished principally by the method of deposition and the structure of the resultant coating-substrate bond. The coating techniques examined are pack cementation, electrospark deposition, physical and chemical vapor deposition, plasma spray, and ion implantation. In addition, ceramic coatings are used in some applications.

  18. Infrared optical coatings in SITP

    Institute of Scientific and Technical Information of China (English)

    LIU Ding-quan; ZHANG Feng-shan

    2005-01-01

    Infrared optical coatings in SITP (Shanghai Institute of Technical Physics) mainly cover the spectrum range from 0.7 μm to 15 μm, and visible and near-UV range are also been included. The coatings are mainly used for metal-reflectance mirrors, Anti-reflection(AR) lens and windows, filters, and dichroic beam splitters. Coatings passed some dependability tests. These optical coated devices usually consist in a remote observing instrument. Most coating materials are commercial products. And one kind of special material PbTe is made by ourselves. Some main results of our research department are reported.

  19. BIODEGRADABLE COATING FROM AGATHIS ALBA

    Directory of Open Access Journals (Sweden)

    NORYAWATI MULYONO

    2012-11-01

    Full Text Available The adhesive property of copal makes it as a potential coating onto aluminum foil to replace polyethylene. This research aimed to develop copal-based coating. The coating was prepared by extracting the copal in ethyl acetate and dipping the aluminium foil in ethyl acetate soluble extract of copal. The characterization of coating included its thickness, weight, thermal and chemical resistance, and biodegradation. The results showed that the coating thickness and weight increased as the copal concentration and dipping frequency increased. Thermal resistance test showed that the coating melted after being heated at 110°C for 30 min. Copal-based coating wasresistant to acidic solution (pH 4.0, water, and coconut oil, but was deteriorated in detergent 1% (w/v and basic solution (pH 10.0. Biodegradability test using Pseudomonas aeruginosa showed weight reduction of 76.82% in 30 days.

  20. Methods for Coating Particulate Material

    Science.gov (United States)

    Littman, Howard (Inventor); Plawsky, Joel L. (Inventor); Paccione, John D. (Inventor)

    2013-01-01

    Methods and apparatus for coating particulate material are provided. The apparatus includes a vessel having a top and a bottom, a vertically extending conduit having an inlet in the vessel and an outlet outside of the vessel, a first fluid inlet in the bottom of the vessel for introducing a transfer fluid, a second fluid inlet in the bottom of the vessel for introducing a coating fluid, and a fluid outlet from the vessel. The method includes steps of agitating a material, contacting the material with a coating material, and drying the coating material to produce a coated material. The invention may be adapted to coat aerogel beads, among other materials. A coated aerogel bead and an aerogel-based insulation material are also disclosed.

  1. Flow accelerated organic coating degradation

    Science.gov (United States)

    Zhou, Qixin

    Applying organic coatings is a common and the most cost effective way to protect metallic objects and structures from corrosion. Water entry into coating-metal interface is usually the main cause for the deterioration of organic coatings, which leads to coating delamination and underfilm corrosion. Recently, flowing fluids over sample surface have received attention due to their capability to accelerate material degradation. A plethora of works has focused on the flow induced metal corrosion, while few studies have investigated the flow accelerated organic coating degradation. Flowing fluids above coating surface affect corrosion by enhancing the water transport and abrading the surface due to fluid shear. Hence, it is of great importance to understand the influence of flowing fluids on the degradation of corrosion protective organic coatings. In this study, a pigmented marine coating and several clear coatings were exposed to the laminar flow and stationary immersion. The laminar flow was pressure driven and confined in a flow channel. A 3.5 wt% sodium chloride solution and pure water was employed as the working fluid with a variety of flow rates. The corrosion protective properties of organic coatings were monitored inline by Electrochemical Impedance Spectroscopy (EIS) measurement. Equivalent circuit models were employed to interpret the EIS spectra. The time evolution of coating resistance and capacitance obtained from the model was studied to demonstrate the coating degradation. Thickness, gloss, and other topography characterizations were conducted to facilitate the assessment of the corrosion. The working fluids were characterized by Fourier Transform Infrared Spectrometer (FTIR) and conductivity measurement. The influence of flow rate, fluid shear, fluid composition, and other effects in the coating degradation were investigated. We conclude that flowing fluid on the coating surface accelerates the transport of water, oxygen, and ions into the coating, as

  2. Photochromic mesoporous hybrid coatings

    Science.gov (United States)

    Raboin, L.; Matheron, M.; Gacoin, T.; Boilot, J.-P.

    2008-09-01

    Spirooxazine (SO) photochromic molecules were trapped in sol-gel matrices. In order to increase the colourability and improve mechanical properties of sol-gel photochromic films, we present an original strategy in which SO photochromic molecules were dispersed in mesoporous organized films using the impregnation technique. Well-ordered organosilicate mesoporous coatings with the 3D-hexagonal symmetry were prepared by the sol-gel technique. These robust mesoporous films, which contain high amounts of hydrophobic methyl groups at the pore surface, offer optimized environments for photochromic dyes dispersed by impregnation technique. After impregnation by a spirooxazine solution, the photochromic response is only slightly slower when compared with mesostructured or soft sol-gel matrices, showing that mesoporous organized hybrid matrix are good host for photochromic dyes. Moreover, the molecular loading in films is easily adjustable in a large range using multi-impregnation procedure and increasing the film thickness leading to coatings for optical switching devices.

  3. Permeability of edible coatings.

    Science.gov (United States)

    Mishra, B; Khatkar, B S; Garg, M K; Wilson, L A

    2010-01-01

    The permeabilities of water vapour, O2 and CO2 were determined for 18 coating formulations. Water vapour transmission rate ranged from 98.8 g/m(2).day (6% beeswax) to 758.0 g/m(2).day (1.5% carboxymethyl cellulose with glycerol). O2 permeability at 14 ± 1°C and 55 ± 5% RH ranged from 1.50 to 7.95 cm(3)cm cm(-2)s(-1)Pa(-1), with CO2 permeability 2 to 6 times as high. Permeability to noncondensable gases (O2 and CO2) was higher for hydrophobic (peanut oil followed by beeswax) coatings as compared to hydrophilic (whey protein concentrate and carboxymethyl cellulose).

  4. Permeability of edible coatings

    OpenAIRE

    B Mishra; Khatkar, B. S.; Garg, M. K.; Wilson, L.A.

    2010-01-01

    The permeabilities of water vapour, O2 and CO2 were determined for 18 coating formulations. Water vapour transmission rate ranged from 98.8 g/m2.day (6% beeswax) to 758.0 g/m2.day (1.5% carboxymethyl cellulose with glycerol). O2 permeability at 14 ± 1°C and 55 ± 5% RH ranged from 1.50 to 7.95 cm3cm cm−2s−1Pa−1, with CO2 permeability 2 to 6 times as high. Permeability to noncondensable gases (O2 and CO2) was higher for hydrophobic (peanut oil followed by beeswax) coatings as compared to hydrop...

  5. Superelastic Orthopedic Implant Coatings

    Science.gov (United States)

    Fournier, Eric; Devaney, Robert; Palmer, Matthew; Kramer, Joshua; El Khaja, Ragheb; Fonte, Matthew

    2014-07-01

    The demand for hip and knee replacement surgery is substantial and growing. Unfortunately, most joint replacement surgeries will fail within 10-25 years, thereby requiring an arduous, painful, and expensive revision surgery. To address this issue, a novel orthopedic implant coating material ("eXalt") has been developed. eXalt is comprised of super elastic nitinol wire that is knit into a three-dimensional spacer fabric structure. eXalt expands in vivo to conform to the implantation site and is porous to allow for bone ingrowth. The safety and efficacy of eXalt were evaluated through structural analysis, mechanical testing, and a rabbit implantation model. The results demonstrate that eXalt meets or exceeds the performance of current coating technologies with reduced micromotion, improved osseointegration, and stronger implant fixation in vivo.

  6. Thermal barrier coating materials

    Directory of Open Access Journals (Sweden)

    David R. Clarke

    2005-06-01

    Full Text Available Improved thermal barrier coatings (TBCs will enable future gas turbines to operate at higher gas temperatures. Considerable effort is being invested, therefore, in identifying new materials with even better performance than the current industry standard, yttria-stabilized zirconia (YSZ. We review recent progress and suggest that an integrated strategy of experiment, intuitive arguments based on crystallography, and simulation may lead most rapidly to the development of new TBC materials.

  7. for zeolite coating

    Directory of Open Access Journals (Sweden)

    Carlos Renato Rambo

    2006-01-01

    Full Text Available Biotemplating is the processing of microcellular ceramics by reproduction of natural morphologies, where the microstructural features of the biotemplate are maintained in the biomorphic ceramic. Different biotemplates with distinct pore anatomies were used to produce biomorphic supports for the zeolite coating: wood, cardboard, sea-sponge and sisal. The biomorphic ceramics were produced by distinguished processing routes: Al-gas infiltration-reaction, liquid-metal infiltration, dip-coating and sol-gel synthesis, in order to produce nitrides, carbides and oxides, depending on the processing conditions. The zeolite coating was performed by hydrothermal growth of MFI-type (Silicalite-1 and ZSM-5 zeolite crystals onto the internal pore walls of the biomorphic templates. The final biomorphic ceramic-zeolite composites were physically characterized, evaluated in terms of their gas adsorption capabilities and correlated to their microstructure and specific pore anatomy. The combination of the properties of the biomorphic ceramics with the adsorption properties of zeolites results in materials with distinct properties as potential candidates for adsorption and catalytic applications due to their characteristic porosity, molecular sieving capabilities and high thermo-mechanical strength.

  8. Coating and curing apparatus and methods

    Energy Technology Data Exchange (ETDEWEB)

    Brophy, Brenor L.; Gonsalves, Peter R.; Maghsoodi, Sina; Colson, Thomas E.; Yang, Yu S.; Abrams, Ze' ev R.

    2016-04-19

    Disclosed is a coating apparatus including flow coating and roll-coating that may be used for uniform sol-gel coating of substrates such as glass, solar panels, windows or part of an electronic display. Also disclosed are methods for substrate preparation, flow coating and roll coating. Lastly, systems and methods for curing sol-gel coatings deposited onto the surface of glass substrates using high temperature air-knives, infrared emitters and direct heat applicators are disclosed.

  9. High-temperature protective coatings on superalloys

    Institute of Scientific and Technical Information of China (English)

    刘培生; 梁开明; 周宏余

    2002-01-01

    Protective coatings are essential for superalloys to serve as blades of gas turb ines at high temperatures, and they primarily include aluminide coating, MCrAlY overlay coating, thermal barrier coating and microcrystalline coating. In this paper, all these high-temperature coatings are reviewed as well as their preparing techniques. Based on the most application and the main failure way, the importance is then presented for further deepgoing study on the high-temperature oxidation law of aluminide coatings.

  10. A New Coating Process for Production of Coated Magnesium Powders

    Science.gov (United States)

    2008-04-16

    TGA data for magnesium hydroxide content. TGA analysis of the as-coated powders is a reproducible and accurate method for the determination of... TGA analysis of the as-coated powder, there is approximately 3wt% magnesium hydroxide present in the material due to the process variation compared...11: Magnesium hydroxide content as measured by TGA analysis for the 1-lb batches of as-coated ground powder Figure 12: Nitrometer analysis of

  11. The analysis of antireflection range in coal seam hydraulic fracturing%本煤层水压致裂增透范围分析

    Institute of Scientific and Technical Information of China (English)

    赵源; 曹树刚; 李勇; 覃乐

    2015-01-01

    that the antireflection range of hy-draulic fracturing is the summation of macro-crack zone, micro-crack crossing zone, micro-crack generation zone (tension zone) and native crack disturbed zone (pressure recovery zone); the growth trend of anti-reflection area which has been obtained by digital image processing ac-cords with quadratic function.

  12. Nanoparticle/Polymer Nanocomposite Bond Coat or Coating

    Science.gov (United States)

    Miller, Sandi G.

    2011-01-01

    This innovation addresses the problem of coatings (meant to reduce gas permeation) applied to polymer matrix composites spalling off in service due to incompatibility with the polymer matrix. A bond coat/coating has been created that uses chemically functionalized nanoparticles (either clay or graphene) to create a barrier film that bonds well to the matrix resin, and provides an outstanding barrier to gas permeation. There is interest in applying clay nanoparticles as a coating/bond coat to a polymer matrix composite. Often, nanoclays are chemically functionalized with an organic compound intended to facilitate dispersion of the clay in a matrix. That organic modifier generally degrades at the processing temperature of many high-temperature polymers, rendering the clay useless as a nano-additive to high-temperature polymers. However, this innovation includes the use of organic compounds compatible with hightemperature polymer matrix, and is suitable for nanoclay functionalization, the preparation of that clay into a coating/bondcoat for high-temperature polymers, the use of the clay as a coating for composites that do not have a hightemperature requirement, and a comparable approach to the preparation of graphene coatings/bond coats for polymer matrix composites.

  13. Dense protective coatings, methods for their preparation and coated articles

    Energy Technology Data Exchange (ETDEWEB)

    Tulyani, Sonia; Bhatia, Tania; Smeggil, John G.

    2015-12-29

    A method for depositing a protective coating on a complex shaped substrate includes the steps of: (1) dipping a complex shaped substrate into a slurry to form a base coat thereon, the slurry comprising an aqueous solution, at least one refractory metal oxide, and at least one transient fluid additive present in an amount of about 0.1 percent to 10 percent by weight of the slurry; (2) curing the dipped substrate; (3) dipping the substrate into a precursor solution to form a top barrier coat thereon; and (4) heat treating the dipped, cured substrate to form a protective coating.

  14. Double-layer antireflection from silver nanoparticle integrated SiO2 layer on silicon wafer: effect of nanoparticle morphology and SiO2 film thickness

    Science.gov (United States)

    Parashar, Piyush K.; Sharma, R. P.; Komarala, Vamsi K.

    2017-01-01

    Optical properties of silver nanoparticles (Ag NPs) on SiO2 thin films of variable thickness, as a plasmonic double layer on a plain silicon wafer, are investigated for broadband antireflection. The light confinement into the silicon is found to be sensitive to the SiO2 film thickness of a few nanometers due to an evanescent character of the Ag NPs’ near-fields. The Ag NPs’ size anisotropy plays a pivotal role in incident light coupling due to the sub-wavelength spatial variation of near-fields at the interface, which leads to reflectance spectrum oscillation behavior in the nanoparticles’ surface plasmon resonance and off-resonance regions. With an optimized SiO2/Ag NP double layer, the average reflectance in the 300-1200 nm spectral range is reduced to 14% in comparison to 42% in bare silicon, with a flat minimum reflectance of 3.5% in the 725-1020 nm spectral region. Finite difference time domain calculations are performed for spatial variation of near-fields and their angular distribution of far-fields at different inhomogeneous interfaces (where near-fields exist). The total reflectance from various configurations is simulated theoretically by considering the experimentally optimized physical parameters of the plasmonic double layer to support the observations. To verify the role of SiO2 surface topology apart from the nanoparticle morphology in plasmon near-field coupling, thermally grown SiO2 films are investigated along with the sputtered SiO2 thin films.

  15. Low Conductivity Thermal Barrier Coatings

    Science.gov (United States)

    Zhu, Dong-Ming

    2005-01-01

    Thermal barrier coatings will be more aggressively designed to protect gas turbine engine hot-section components in order to meet future engine higher fuel efficiency and lower emission goals. In this presentation, thermal barrier coating development considerations and requirements will be discussed. An experimental approach is established to monitor in real time the thermal conductivity of the coating systems subjected to high-heat-flux, steady-state and cyclic temperature gradients. Advanced low conductivity thermal barrier coatings have also been developed using a multi-component defect clustering approach, and shown to have improved thermal stability. The durability and erosion resistance of low conductivity thermal barrier coatings have been improved utilizing advanced coating architecture design, composition optimization, in conjunction with more sophisticated modeling and design tools.

  16. Pipeline integrity : control by coatings

    Energy Technology Data Exchange (ETDEWEB)

    Khanna, A.S. [Indian Inst. of Technology, Bombay (India)

    2008-07-01

    This presentation provided background information on the history of cross-country pipelines in India. It discussed the major use of gas. The key users were described as being the power and fertilizer industries, followed by vehicles using compressed natural gas to replace liquid fuels and thereby reduce pollution. The presentation also addressed the integrity of pipelines in terms of high production, safety, and monitoring. Integrity issues of pipelines were discussed with reference to basic design, control of corrosion, and periodic health monitoring. Other topics that were outlined included integrity by corrosion control; integrity by health monitoring; coatings requirements; classification of UCC pipeline coatings; and how the pipeline integrity approach can help to achieve coatings which give design life without any failure. Surface cleanliness, coating conditions, and the relationship between temperature of Epoxy coating and the time of adhesive coating were also discussed. Last, the presentation provided the results of an audit of the HBJ pipeline conducted from 1999 to 2000. tabs., figs.

  17. Functional Coatings with Polymer Brushes

    OpenAIRE

    König, Meike

    2013-01-01

    The scope of this work is to fathom different possibilities to create functional coatings with polymer brushes. The immobilization of nanoparticles and enzymes is investigated, as well as the affection of their properties by the stimuli-responsiveness of the brushes. Another aspect is the coating of 3D-nanostructures by polymer brushes and the investigation of the resulting functional properties of the hybrid material. The polymer brush coatings are characterized by a variety of microscopic a...

  18. Article Including Environmental Barrier Coating System

    Science.gov (United States)

    Lee, Kang N. (Inventor)

    2015-01-01

    An enhanced environmental barrier coating for a silicon containing substrate. The enhanced barrier coating may include a bond coat doped with at least one of an alkali metal oxide and an alkali earth metal oxide. The enhanced barrier coating may include a composite mullite bond coat including BSAS and another distinct second phase oxide applied over said surface.

  19. Protective coatings on extensible biofibres

    Science.gov (United States)

    Holten-Andersen, Niels; Fantner, Georg E.; Hohlbauch, Sophia; Waite, J. Herbert; Zok, Frank W.

    2007-09-01

    Formulating effective coatings for use in nano- and biotechnology poses considerable technical challenges. If they are to provide abrasion resistance, coatings must be hard and adhere well to the underlying substrate. High hardness, however, comes at the expense of extensibility. This property trade-off makes the design of coatings for even moderately compliant substrates problematic, because substrate deformation easily exceeds the strain limit of the coating. Although the highest strain capacity of synthetic fibre coatings is less than 10%, deformable coatings are ubiquitous in biological systems. With an eye to heeding the lessons of nature, the cuticular coatings of byssal threads from two species of marine mussels, Mytilus galloprovincialis and Perna canaliculus, have been investigated. Consistent with their function to protect collagenous fibres in the byssal-thread core, these coatings show hardness and stiffness comparable to those of engineering plastics and yet are surprisingly extensible; the tensile failure strain of P. canaliculus cuticle is about 30% and that of M. galloprovincialis is a remarkable 70%. The difference in extensibility is attributable to the presence of deformable microphase-separated granules within the cuticle of M. galloprovincialis. The results have important implications in the design of bio-inspired extensible coatings.

  20. Corrosion behavior of duplex coatings

    Directory of Open Access Journals (Sweden)

    K. Raghu Ram Mohan Reddy

    2016-07-01

    Full Text Available The titanium alloys are used in defense, aerospace, automobile, chemical plants and biomedical applications due to their very high strength and lightweight properties. However, corrosion is a life-limiting factor when Ti alloys are exposed to different chemical environments at high temperatures. In the present paper, duplex NiCrAlY/WC–Co coating is coated onto Ti6Al4V substrate to investigate the corrosion behavior of both coated samples and the substrate. The duplex coating was performed with NiCrAlY as the intermediate coat of 200 μm thickness deposited by HVOF process and WC–Co ceramic top coat with varying thicknesses of 250 μm, 350 μm and 450 μm deposited by DS process. Potentiodynamic polarization tests were employed to investigate the corrosion performance of duplex coated samples and substrate in Ringer’s solution at 37 °C and pH value was set to 5.7. Finally the results reveal that 350 μm thick coated samples showed highest corrosion resistance compared to 250 μm thick samples as well as bare substrate. However, the 450 μm thick coated sample showed poor corrosion resistance compared to the substrate. The scale formed on the samples upon corrosion was characterized by using SEM analysis to understand the degree of corrosion behavior.

  1. Coatings Technology Integration Office (CTIO)

    Data.gov (United States)

    Federal Laboratory Consortium — CTIO serves as the Air Force's central resource for aircraft coating systems and their applications. CTIO's primary objectives are pollution prevention and improved...

  2. Electrochemically switchable polypyrrole coated membranes

    Energy Technology Data Exchange (ETDEWEB)

    Weidlich, Claudia, E-mail: weidlich@dechema.d [DECHEMA e.V., Karl-Winnacker-Institut, Theodor-Heuss-Allee 25, D-60486 Frankfurt am Main (Germany); Mangold, Klaus-Michael [DECHEMA e.V., Karl-Winnacker-Institut, Theodor-Heuss-Allee 25, D-60486 Frankfurt am Main (Germany)

    2011-04-01

    A method for coating membranes with polypyrrole (PPy) has been developed. Different membranes, such as microfiltration as well as ion exchanger membranes have been coated with PPy to yield electrical conductivity of the membranes. The coated membranes have been investigated by cyclic voltammetry and scanning electron microscopy and their permeability and permselectivity have been tested. The results show that PPy can be tailored as cation or anion exchanger and its porosity can be controlled to avoid any impairment of the membrane by the polymer layer. These PPy coated membranes can be applied as electrochemically switchable, functionalised membranes with controllabel and variable separation properties.

  3. Studies on Nanocomposite Conducting Coatings

    Directory of Open Access Journals (Sweden)

    Amitava Bhattacharyya

    2013-01-01

    Full Text Available Nanocomposite conducting coatings can impart stable surface electrical conductivity on the substrate. In this paper, carbon nanofiber (CNF and nanographite (NG are dispersed in thermoplastic polyurethane matrix and coated on the surface of glass and polyethylene terephthalate (PET film. The nanoparticles dispersion was studied under TEM. The coating thicknesses were estimated. Further, their resistance and impedance were measured. It has been observed that the 5 wt% CNF dispersed nanocomposite coatings show good conductivity. The use of NG can bring down the amount of CNF; however, NG alone has failed to show significant improvement in conductivity. The nanocomposite coating on PET film using 2.5 wt% of both CNF and NG gives frequency-independent impedance which indicates conducting network formation by the nanoparticles. The study was carried out at different test distances on nanocomposite coated PET films to observe the linearity and continuity of the conducting network, and the result shows reasonable linearity in impedance over total test length (from 0.5 cm to 4.5 cm. The impedance of nanocomposite coatings on glass is not frequency independent and also not following linear increase path with distance. This indicates that the dispersion uniformity is not maintained in the coating solution when it was coated on glass.

  4. Mold and Crucible Coatings

    Science.gov (United States)

    1986-04-28

    34;" -"""-"’" " " ""’’ "" "" ’"" ’ j * AD I. AT)-E 9 7 W CONTRACTOR REPORT ARCCD-CR-86007 MOLD AND CRUCIBLE COATINGS Sylvia J. Canino Arthur L. Geary Nuclear...IFnlRpr April 1984_-_December 198, .. AUTNORfo) S. CONTRACT on CRAM? # "I MWef(e)I Sylvia J. Canino and Arthur L. Geary DAAK1O-84-C-0056 PERFORMING

  5. USAF Inorganic Coating Successes

    Science.gov (United States)

    2012-08-01

    in2 (Marginal Fail) 7 or more pits were seen in a total of 30 in2 (Fail) Aluminum CFCC Screening Test Results Conversion Coating Alloy OC-ALC... 6061 168+ Hours 7075 168+ Hours 2024 48 Hours 5052 48-72 Hours 72-168+ Hours (5 pits on one panel at 48 hours, but then no more ) 6061 72...Dichromate Sealer Test Results Sealer Substrate Quality Thickness Corrosion Primer Dry Tape Adhesion Wet Tape Adhesion Baseline 1 Al 2024-T3 PASS

  6. Thermal Protective Coatings

    Science.gov (United States)

    1976-03-31

    within 2 minutes for the No. 4. Sodiurn silicate was tested with alumnnunm hydroxide, nerlite, vermiculite and borax filler systems. None of the systems...1.27 cm) thick, 3/16 inch (0.48 cm) cell size, 5.5 lbs/ft 3 (88.1 kg/m 3 ) glass/phenolic honey - p comib set into the fire retardant maLerial. The sheets...COATING SPECIMEN PERCENT BY WEIGHT THICKNESS WEIGHT ANO. MATRIX FILLrR 1’fLS (CM) LBS/FT. (kg,’-), 26 50% Shell 828 Epoxy Resin Borax - 54 (.14) .39

  7. Microplasma sprayed hydroxyapatite coatings

    CERN Document Server

    Dey, Arjun

    2015-01-01

    ""This unique book on development of microplasma sprayed HAp coating has been organized in a very compact yet comprehensive manner. This book also highlights the horizons of future research that invites the attention of global community, particularly those in bio-medical materials and bio-medical engineering field. This book will surely act as a very useful reference material for both graduate/post-graduate students and researchers in the field of biomedical, orthopedic and manufacturing engineering and research. I truly believ that this is the first ever effort which covers almost all the

  8. Dry coating, a novel coating technology for solid pharmaceutical dosage forms.

    Science.gov (United States)

    Luo, Yanfeng; Zhu, Jesse; Ma, Yingliang; Zhang, Hui

    2008-06-24

    Dry coating is a coating technology for solid pharmaceutical dosage forms derived from powder coating of metals. In this technology, powdered coating materials are directly coated onto solid dosage forms without using any solvent, and then heated and cured to form a coat. As a result, this technology can overcome such disadvantages caused by solvents in conventional liquid coating as serious air pollution, high time- and energy-consumption and expensive operation cost encountered by liquid coating. Several dry coating technologies, including plasticizer-dry-coating, electrostatic-dry-coating, heat-dry-coating and plasticizer-electrostatic-heat-dry-coating have been developed and extensively reported. This mini-review summarized the fundamental principles and coating processes of various dry coating technologies, and thoroughly analyzed their advantages and disadvantages as well as commercialization potentials.

  9. Alternative HTS coated conductors

    Science.gov (United States)

    Blaugher, R. D.; Bhattacharya, R. N.; Chen, J.; Padmanabhan, R.

    2002-10-01

    The availability of Bi-2223 high-temperature-superconductor (HTS) powder-in-tube (PIT) tape, with acceptable performance for long lengths, has provided the ability to construct a wide range of HTS electric power components. As a result, there are major worldwide projects in developing HTS electric power components for demonstration in a utility environment. Utility acceptance for superconducting power equipment will depend on several key factors: improved system performance, lower life-cycle costs, higher efficiency versus conventional technology, reliability and maintenance comparable to conventional power equipment, and a competitive installed cost. The latter is impacted by the current high cost of HTS conductors, which must be lowered to costs comparable to conventional Nb-Ti wire, i.e., $2-5/kAm. The present performance and cost of state-of-the-art Bi-2223 HTS tape, although acceptable for prototype construction, is viewed as a major deterrent that may compromise eventual commercialization for most of these electric power devices. The so-called second-generation coated conductor development, with emphasis on conductors employing HTS YBCO films, is viewed as the solution to this performance and cost issue. The potential for the Tl, Hg, and Bi-oxide superconductors for producing an HTS tape as alternatives to Bi-2223 PIT (and YBCO) will be discussed with some recent results on Bi-2212 “coated conductor” development.

  10. Westinghouse thermal barrier coatings development

    Energy Technology Data Exchange (ETDEWEB)

    Goedjen, J.G.; Wagner, G. [Westinghouse Electric Corp., Orlando, FL (United States)

    1995-10-01

    Westinghouse, in conjunction with the Department of Energy and Oak Ridge National Laboratory, has embarked upon a program for the development of advanced thermal barrier coatings for industrial gas turbines. Development of thermal barrier coatings (TBC`s) for industrial gas turbines has relied heavily on the transfer of technology from the aerospace industry. Significant differences in the time/temperature/stress duty cycles exist between these two coating applications. Coating systems which perform well in aerospace applications may not been optimized to meet power generation performance requirements. This program will focus on development of TBC`s to meet the specific needs of power generation applications. The program is directed at developing a state-of-the-art coating system with a minimum coating life of 25,000 hours at service temperatures required to meet increasing operating efficiency goals. Westinghouse has assembled a team of university and industry leaders to accomplish this goal. Westinghouse will coordinate the efforts of all program participants. Chromalloy Turbine Technologies, Inc. and Sermatech International, Inc. will be responsible for bond coat and TBC deposition technology. Praxair Specialty Powders, Inc. will be responsible for the fabrication of all bond coat and ceramic powders for the program. Southwest Research Institute will head the life prediction modelling effort; they will also be involved in coordinating nondestructive evaluation (NDE) efforts. Process modelling will be provided by the University of Arizona.

  11. Pack cementation coatings for alloys

    Energy Technology Data Exchange (ETDEWEB)

    He, Yi-Rong; Zheng, Minhui; Rapp, R.A. [Ohio State Univ., Columbus, OH (United States)

    1996-08-01

    The halide-activated pack cementation process was modified to produce a Ge-doped silicide diffusion coating on a Cr-Cr{sub 2}Nb alloy in a single processing step. The morphology and composition of the coating depended both on the composition of the pack and on the composition and microstructure of the substrate. Higher Ge content in the pack suppressed the formation of CrSi{sub 2} and reduced the growth kinetics of the coating. Ge was not homogeneously distributed in the coatings. In cyclic and isothermal oxidation in air at 700 and 1050{degrees}C, the Ge-doped silicide coating protected the Cr-Nb alloys from significant oxidation by the formation of a Ge-doped silica film. The codeposition and diffusion of aluminum and chromium into low alloy steel have been achieved using elemental Al and Cr powders and a two-step pack cementation process. Sequential process treatments at 925{degrees}C and 1150{degrees}C yield dense and uniform ferrite coatings, whose compositions are close to either Fe{sub 3}Al or else FeAl plus a lower Cr content, when processed under different conditions. The higher content of Al in the coatings was predicted by thermodynamic calculations of equilibrium in the gas phase. The effect of the particle size of the metal powders on the surface composition of the coating has been studied for various combinations of Al and Cr powders.

  12. POWDER COATINGS: A TECHNOLOGY REVIEW

    Science.gov (United States)

    In 1995, surface coatings accounted for nearly 2.55 million Mg of volatile organic compound (VOC) emissions nationally, which is more than 12% of VOC emissions from all sources. In recent years, powder coatings have been steadily gaining popularity as an alternative to solvent-bo...

  13. Foundry Coating Technology: A Review

    DEFF Research Database (Denmark)

    Nwaogu, Ugochukwu Chibuzoh; Tiedje, Niels Skat

    2011-01-01

    is important. In this review, a detailed description of these topics and examples are provided where necessary. A potential area of research in foundry coating development, using sol-gel process is suggested. The application of sol-gel technology in the development of foundry coatings is a novel approach....

  14. External coating of colonic anastomoses

    DEFF Research Database (Denmark)

    Pommergaard, Hans-Christian; Achiam, Michael Patrick; Rosenberg, Jacob

    2012-01-01

    Colon anastomotic leakage remains both a frequent and serious complication in gastrointestinal surgery. External coating of colonic anastomoses has been proposed as a means to lower the rate of this complication. The aim of this review was to evaluate existing studies on external coating of colonic...

  15. Bright Prospects for Fluorine Coatings

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Fluorine coatings are a category of new coatings with fluorine-containing resins as the major film forming substances.They have excellent weather resistance,solvent resistance, acid/alkali resistance, no toxicity and no hazards,and they contribute to film stability.

  16. Intumescent coatings under fast heating

    DEFF Research Database (Denmark)

    Nørgaard, Kristian Petersen; Dam-Johansen, Kim; Català, Pere

    2012-01-01

    Intumescent coatings are widely used to delay or minimise the destructive effects of fire. They are usually tested under conditions that simulate the relatively slow build-up of heat in a normal fire. Here, the effects of damage during a fire causing sudden heating of the coating were studied....

  17. Lignin based controlled release coatings

    NARCIS (Netherlands)

    Mulder, W.J.; Gosselink, R.J.A.; Vingerhoeds, M.H.; Harmsen, P.F.H.; Eastham, D.

    2011-01-01

    Urea is a commonly used fertilizer. Due to its high water-solubility, misuse easily leads to excess nitrogen levels in the soil. The aim of this research was to develop an economically feasible and biodegradable slow-release coating for urea. For this purpose, lignin was selected as coating material

  18. Moisture transport in coated wood

    NARCIS (Netherlands)

    Meel, P.A. van; Erich, S.J.F.; Huinink, H.P.; Kopinga, K.; Jong, J. DE; Adan, O.C.G.

    2011-01-01

    Moisture accumulation inside wood causes favorable conditions for decay. Application of a coating alters the moisture sorption of wood and prevents accumulation of moisture. This paper presents the results of a nuclear magnetic resonance (NMR) study on the influence of a coating on the moisture abso

  19. Coating of silicon pore optics

    DEFF Research Database (Denmark)

    Cooper-Jensen, Carsten P.; Ackermann, M.; Christensen, Finn Erland;

    2009-01-01

    For the International X-ray observatory (IXO), a mirror module with an effective area of 3 m2 at 1.25 keV and at least 0.65 m2 at 6 keV has to be realized. To achieve this goal, coated silicon pore optics has been developed over the last years. One of the challenges is to coat the Si plates...... and still to realize Si-Si bonding. It has been demonstrated that ribbed silicon plates can be produced and assembled into stacks. All previously work has been done using uncoated Si plates. In this paper we describe how to coat the ribbed Si plates with an Ir coating and a top C coating through a mask so...

  20. Dynamic residual stress in thermal sprayed coatings

    Institute of Scientific and Technical Information of China (English)

    Wang Zhiping; Yang Yuanyuan

    2005-01-01

    With the modified Almen method, the forming and development process of residual stress in a thermal sprayed coating has been obtained. The test results identify that the residual stress in a coating is depend on coating material properties, technique and coating thickness. The paper pays much attention to the hysteresis between the coating temperature and residual stress in the coating or between the applied stress and the strain of the coating, and confirms that the fact is resulted from the"Gas Fix" character of a thermal sprayed coating.

  1. Dip coating process. Silicon sheet growth development for the large-area silicon sheet task of the low-cost silicon solar array project. Quarterly report No. 6, March 22, 1977--June 24, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Zook, J.D.; Heaps, J.D.; Maciolek, R.B.; Koepke, B.; Butter, C.D.; Schuldt, S.B.

    1977-06-30

    The objective of this research program is to investigate the technical and economic feasibility of producing solar-cell-quality sheet silicon by coating one surface of carbonized ceramic substrates with a thin layer of large-grain polycrystalline silicon from the melt. Significant progress was made in silicon on ceramic (SOC) solar cell performance. SOC cells having 1 cm/sup 2/ active areas demonstrated measured conversion efficiencies as high as 7.2 percent. Typical open circuit voltages (V/sub oc/) and short circuit current densities (J/sub sc/) were 0.51 volt and 20 mA/cm/sup 2/ respectively. Since the active surface of these solar cells is a highly reflective ''as-grown'' surface, one can expect improvement in J/sub sc/ after an anti-reflection (AR) coating is applied. It is significant that single-crystal comparison cells, also measured without benefit of an AR coating, had efficiencies in the 8.5 percent range with typical V/sub oc/'s and J/sub sc/'s of 0.54 volt and 23 mA/cm/sup 2/, respectively. Therefore, improvement in cell design and junction diffusion techniques should increase the efficiency of both the SOC and single-crystal cells. During this quarter the dip coating facility was inadvertently contaminated, but has since been restored to a purity level exceeding its original state. With this facility, silicon coatings were grown with a single-crystal seed attached to the substrate. Single-crystal silicon was not forthcoming, but the results were nonetheless encouraging. Several of the carbon coating types tried appear promising, including one which has high purity and can be applied uniformly by swab or airbrush.

  2. Tribological Performance of Coated Surfaces

    Institute of Scientific and Technical Information of China (English)

    Kenneth Holmberg; Anssi Laukkanen

    2004-01-01

    The fundamentals of coating tribology is presented in a generalised holistic approach to friction and wear mechanisms of coated surfaces in dry sliding contacts. It is based on a classification of the tribological contact process into macromechanical, micromechanical, tribochemical contact mechanisms and material transfer. The tribological contact process is dominated by the macromechanical mechanisms, which have been systematically analysed by using four main parameters: the coating-to-substrate hardness relationship, the film thickness, the surface roughness and the debris in the contact. In this paper special attention is given to the microlevel mechanisms, and in particular new techniques for modelling the elastic, plastic and brittle behaviour of the surface by finite element (FEM) computer simulations. The contact condition with a sphere sliding over a plate coated with a very thin hard coating is analysed. A three dimensional FEM model has been developed for calculating the first principal stress distribution in the scratch tester contact of a diamond spherical tip moving with increased load on a 2 μm thick titanium nitride (TiN) coated steel surface. The model is comprehensive in that sense that it considers elastic, plastic and fracture behaviour of the contact surfaces. By identifying from a scratch experiment the location of the first crack and using this as input data can the fracture toughness of the coating be determined.

  3. Solar collectors: Technical progress report No. 2, 5 March 1979-5 December 1979

    Energy Technology Data Exchange (ETDEWEB)

    Baum, B.; Binette, M.

    1980-03-14

    The following work is reviewed: accelerated ultraviolet exposure of glazing and housing materials, the evaluation of ultraviolet protective coatings and films, and investigation of antireflective coatings.

  4. Suppressing lossy-film-induced angular mismatches between reflectance and transmittance extrema: optimum optical designs of interlayers and AR coating for maximum transmittance into active layers of CIGS solar cells.

    Science.gov (United States)

    Chang, Yin-Jung

    2014-01-13

    The investigation of optimum optical designs of interlayers and antireflection (AR) coating for achieving maximum average transmittance (T(ave)) into the CuIn(1-x)Ga(x)Se2 (CIGS) absorber of a typical CIGS solar cell through the suppression of lossy-film-induced angular mismatches is described. Simulated-annealing algorithm incorporated with rigorous electromagnetic transmission-line network approach is applied with criteria of minimum average reflectance (R(ave)) from the cell surface or maximum T(ave) into the CIGS absorber. In the presence of one MgF2 coating, difference in R(ave) associated with optimum designs based upon the two distinct criteria is only 0.3% under broadband and nearly omnidirectional incidence; however, their corresponding T(ave) values could be up to 14.34% apart. Significant T(ave) improvements associated with the maximum-T(ave)-based design are found mainly in the mid to longer wavelengths and are attributed to the largest suppression of lossy-film-induced angular mismatches over the entire CIGS absorption spectrum. Maximum-T(ave)-based designs with a MgF2 coating optimized under extreme deficiency of angular information is shown, as opposed to their minimum-R(ave)-based counterparts, to be highly robust to omnidirectional incidence.

  5. Integrated Glass Coating Manufacturing Line

    Energy Technology Data Exchange (ETDEWEB)

    Brophy, Brenor [Enki Technology Inc., San Jose, CA (United States)

    2015-09-30

    This project aims to enable US module manufacturers to coat glass with Enki’s state of the art tunable functionalized AR coatings at the lowest possible cost and highest possible performance by encapsulating Enki’s coating process in an integrated tool that facilitates effective process improvement through metrology and data analysis for greater quality and performance while reducing footprint, operating and capital costs. The Phase 1 objective was a fully designed manufacturing line, including fully specified equipment ready for issue of purchase requisitions; a detailed economic justification based on market prices at the end of Phase 1 and projected manufacturing costs and a detailed deployment plan for the equipment.

  6. Intumescent Coatings as Fire Retardants

    Science.gov (United States)

    Parker, J. A.; Fohlen, G. M.; Sawko, P. M.; Fish, R. H.

    1970-01-01

    The development of fire-retardant coatings to protect surfaces which may be exposed to fire or extreme heat is a subject of intense interest to many industries. A fire-retardant paint has been developed which represents a new chemical approach for preparing intumescent coatings, and potentially, is very important to fire-prevention authorities. The requirements for a superior coating include ease of application, suitability to a wide variety of surfaces and finishes, and stability over an extended period of time within a broad range of ambient temperature and humidity conditions. These innovative coatings, when activated by the heat of a fire, react to form a thick, low-density, polymeric coating or char layer. Water vapor and sulphur dioxide are released during the intumescent reaction. Two fire-protection mechanisms thus become available: (1) the char layer retards the flow of heat, due to the extremely low thermal conductivity; and (2) water vapor and sulfur dioxide are released, providing fire quenching properties. Still another mechanism functions in cases where the char, by virtue of its high oxidation resistance and low thermal conductivity, reaches a sufficiently high temperature to re-radiate much of the incident heat load. The coatings consist of dispersions of selective salts of a nitro-amino-arornatic compound. Specifically, para-nitroaniline bisulfate and the ammonium salt of para-nitroaniline-ortho sulphuric acid (2-amino-5-nitrobenzenesulphuric acid) are used. Suitable vehicles are cellulose nitrate of lacquer grade, a nitrite-phenolic modified rubber, or epoxy-polysulfide copolymer. Three separate formulations have been developed. A solvent is usually employed, such as methylethyl ketone, butyl acetate, or toluene, which renders the coatings suitably thin and which evaporates after the coatings are applied. Generally, the intumescent material is treated as insoluble in the vehicle, and is ground and dispersed in the vehicle and solvent like an

  7. Inhomogeneous interface laser mirror coatings.

    Science.gov (United States)

    Ledger, A M

    1979-09-01

    Methods of improving the durability of thin-film laser mirror coatings for 10.6 microm using thorium fluoride, zinc selenide, and zinc sulfide materials have been investigated. The largest improvement in film durability was obtained by using inhomogeneous interface fabrication for all the dielectric-dielectric interfaces and by incorporating cerium fluoride protective overcoating material into the film design. Experimental results are given for enhanced reflectors, polarization-selective coatings, and buried-grating aperture-sharing coatings designed for high-power laser applications.

  8. Laser-based coatings removal

    Energy Technology Data Exchange (ETDEWEB)

    Freiwald, J.G.; Freiwald, D.A. [F2 Associates, Inc., Albuquerque, NM (United States)

    1995-10-01

    Over the years as building and equipment surfaces became contaminated with low levels of uranium or plutonium dust, coats of paint were applied to stabilize the contaminants in place. Most of the earlier paint used was lead-based paint. More recently, various non-lead-based paints, such as two-part epoxy, are used. For D&D (decontamination and decommissioning), it is desirable to remove the paints or other coatings rather than having to tear down and dispose of the entire building. This report describes the use of pulse-repetetion laser systems for the removal of paints and coatings.

  9. Water permeability of pigmented waterborne coatings

    NARCIS (Netherlands)

    Donkers, P.A.J.; Huinink, H.P.; Erich, S.J.F.; Reuvers, N.J.W.; Adan, O.C.G.

    2013-01-01

    Coatings are used in a variety of applications. Last decades more and more coating systems are transforming from solvent to waterborne coating systems. In this study the influence of pigments on the water permeability of a waterborne coating system is studied, with special interest in the possible i

  10. Overlay metallic-cermet alloy coating systems

    Science.gov (United States)

    Gedwill, M. A.; Levine, S. R.; Glasgow, T. K. (Inventor)

    1984-01-01

    A substrate, such as a turbine blade, vane, or the like, which is subjected to high temperature use is coated with a base coating of an oxide dispersed, metallic alloy (cermet). A top coating of an oxidation, hot corrosion, erosion resistant alloy of nickel, cobalt, or iron is then deposited on the base coating. A heat treatment is used to improve the bonding. The base coating serves as an inhibitor to interdiffusion between the protective top coating and the substrate. Otherwise, the protective top coating would rapidly interact detrimentally with the substrate and degrade by spalling of the protective oxides formed on the outer surface at elevated temperatures.

  11. Protective coatings for commercial particulates

    DEFF Research Database (Denmark)

    Kindl, B.; Teng, Y.H.; Liu, Y.L.

    1994-01-01

    SiC/Al composites are in large-scale production with Al-Si alloy matrices. The same composites with pure Al or low Si matrices need diffusion barriers on the SiC reinforcement to control the interfacial reaction. The present paper describes various approaches taken to obtain protective coatings...... of alumina and zirconia on SiC particulates by sol-gel techniques. Aqueous and organic precursors have been used. The extent of the reaction, i.e., the Si and Al4C3 content in the matrix, was determined by differential thermal analysis and X-ray diffraction. The reaction rates of some coated particulates...... in liquid Al are decreased by as much as one order of magnitude during the first 15 min of immersion. Pretreatments of the SiC surface, the composition and thickness of the coating interphase and heat treatments of the coated materials have been studied, and are discussed in relation to their effect...

  12. DLC coatings for hydraulic applications

    Institute of Scientific and Technical Information of China (English)

    Luca NOBILI; Luca MAGAGNIN

    2009-01-01

    Replacement of lubricating oils with water or low-viscosity fluids is highly desirable in many industrial fields, on account of the environmental and economical advantages. Low lubricity of water might be insufficient for proper operation of hydraulic components, and diamond-like carbon(DLC) coatings are very attractive as solid lubricant films. A remote-plasma PACVD process was utilized to deposit hydrogenated DLC coatings (a-C:H) on different substrates. Microindentation measurements show that the coating hardness is around 35 GPa. Tribological behavior was evaluated by block-on-ring tests performed in water and water with alumina. The wear rate was calculated after measuring the wear volume by a laser profilemeter. Morphological and compositional analysis of the wear tracks reveal that coating failure may occur by abrasive wear or delamination, depending on the substrate properties. Hard and smooth substrates give the best results and dispersed alumina particles increase the wear rate.

  13. Corrosion-resistant metallic coatings

    Directory of Open Access Journals (Sweden)

    F. Presuel-Moreno

    2008-10-01

    Full Text Available We describe recent computational and experimental studies on the corrosion properties of metallic coatings that can be tailored (tuned to deliver up to three corrosion-inhibiting functions to an underlying substrate. Attributes are tuned by a selection of alloy compositions and nanostructures, ideally in alloy systems that offer flexibility of choice to optimize the corrosion-resisting properties. An amorphous Al-based coating is tuned for corrosion protection by on-demand release of ionic inhibitors to protect defects in the coating, by formation of an optimized barrier to local corrosion in Cl− containing environments, as well as by sacrificial cathodic prevention. Further progress in this field could lead to the design of the next generation of adaptive or tunable coatings that inhibit corrosion of underlying substrates.

  14. Smart Coatings for Corrosion Protection

    Science.gov (United States)

    Calle, Luz Marina; Li, Wendy; Buhrow, Jerry W.; Johnsey, Marissa N.

    2016-01-01

    Nearly all metals and their alloys are subject to corrosion that causes them to lose their structural integrity or other critical functionality. It is essential to detect corrosion when it occurs, and preferably at its early stage, so that action can be taken to avoid structural damage or loss of function. Protective coatings are the most commonly used method of corrosion control. However, progressively stricter environmental regulations have resulted in the ban of many commercially available corrosion protective coatings due to the harmful effects of their solvents or corrosion inhibitors. This work concerns the development of a multifunctional, smart coating for the autonomous control of corrosion. This coating is being developed to have the inherent ability to detect the chemical changes associated with the onset of corrosion and respond autonomously to indicate it and control it.

  15. Cementless Hydroxyapatite Coated Hip Prostheses

    Directory of Open Access Journals (Sweden)

    Antonio Herrera

    2015-01-01

    Full Text Available More than twenty years ago, hydroxyapatite (HA, calcium phosphate ceramics, was introduced as a coating for cementless hip prostheses. The choice of this ceramic is due to its composition being similar to organic apatite bone crystals. This ceramic is biocompatible, bioactive, and osteoconductive. These qualities facilitate the primary stability and osseointegration of implants. Our surgical experience includes the implantation of more than 4,000 cementless hydroxyapatite coated hip prostheses since 1990. The models implanted are coated with HA in the acetabulum and in the metaphyseal area of the stem. The results corresponding to survival and stability of implants were very satisfactory in the long-term. From our experience, HA-coated hip implants are a reliable alternative which can achieve long term survival, provided that certain requirements are met: good design selection, sound choice of bearing surfaces based on patient life expectancy, meticulous surgical technique, and indications based on adequate bone quality.

  16. Low Temperature Cure Powder Coatings

    Science.gov (United States)

    2013-05-01

    within the JTP. These requirements included a final coating thickness range, a minimum product shelf life, and finished surface quality as measured...additional drawbacks of PC technology. Technology innovations such as Ultraviolet ( UV ) curable powders, which are not constrained by physical oven size due... Thickness Film thickness measurements were also taken from the same color measurement locations across each component’s coated surface. During field

  17. Hermetic Coating of Optical Fibers

    Science.gov (United States)

    1987-11-01

    of 450A/min. A number of bulk samples were coated with a-C:H including microscope slides, NaCl plates, ZBLAN fluoride glass and sapphire blanks. IR...deposition were identified. Bulk NaCl, sapphire and glass samples coated with - 1 micron thick films were tested analytically. With the information gathered...1.0 INTRODUCTION: The surface of a freshly drawn glass fiber while seemingly smooth has many imperfections which when under stress, can grow and

  18. Corrosion resistant neutron absorbing coatings

    Science.gov (United States)

    Choi, Jor-Shan [El Cerrito, CA; Farmer, Joseph C [Tracy, CA; Lee, Chuck K [Hayward, CA; Walker, Jeffrey [Gaithersburg, MD; Russell, Paige [Las Vegas, NV; Kirkwood, Jon [Saint Leonard, MD; Yang, Nancy [Lafayette, CA; Champagne, Victor [Oxford, PA

    2012-05-29

    A method of forming a corrosion resistant neutron absorbing coating comprising the steps of spray or deposition or sputtering or welding processing to form a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material. Also a corrosion resistant neutron absorbing coating comprising a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material.

  19. Corrosion-resistant metallic coatings

    OpenAIRE

    F. Presuel-Moreno; M.A. Jakab; N. Tailleart; Goldman, M.; J. R. Scully

    2008-01-01

    We describe recent computational and experimental studies on the corrosion properties of metallic coatings that can be tailored (tuned) to deliver up to three corrosion-inhibiting functions to an underlying substrate. Attributes are tuned by a selection of alloy compositions and nanostructures, ideally in alloy systems that offer flexibility of choice to optimize the corrosion-resisting properties. An amorphous Al-based coating is tuned for corrosion protection by on-demand release of ionic i...

  20. Material Science Smart Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Rubinstein, A. I. [Univ. of Nebraska Medical Center, Omaha, NE (United States); Sabirianov, R. F. [Univ. of Nebraska Medical Center, Omaha, NE (United States); Namavar, Fereydoon [Univ. of Nebraska Medical Center, Omaha, NE (United States)

    2014-07-01

    The contribution of electrostatic interactions to the free energy of binding between model protein and a ceramic implant surface in the aqueous solvent, considered in the framework of the nonlocal electrostatic model, is calculated as a function of the implant low-frequency dielectric constant. We show that the existence of a dynamically ordered (low-dielectric) interfacial solvent layer at the protein-solvent and ceramic-solvent interface markedly increases charging energy of the protein and ceramic implant, and consequently makes the electrostatic contribution to the protein-ceramic binding energy more favorable (attractive). Our analysis shows that the corresponding electrostatic energy between protein and oxide ceramics depends nonmonotonically on the dielectric constant of ceramic, εC. Obtained results indicate that protein can attract electrostatically to the surface if ceramic material has a moderate εC below or about 35 (in particularly ZrO2 or Ta2O5). This is in contrast to classical (local) consideration of the solvent, which demonstrates an unfavorable electrostatic interaction of protein with typical metal oxide ceramic materials (εC>10). Thus, a solid implant coated by combining oxide ceramic with a reduced dielectric constant can be beneficial to strengthen the electrostatic binding of the protein-implant complex.

  1. Composite hydrophilic coating for conditioner aluminum fins

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    To solve the so-called "white rust" and 'water bridge" problems of the aluminum fins for heat exchanger of automobile air conditioner, aimed at nationalizing the art of hydrophilic coating technology, the choice of coating forming and curing materials was investigated. By measuring the water contact angle, SEM surface scanning and ingredients analysis of the coating, optimal parameters and composition are acquired. The coating forming mechanisms of the composition was also expatiated. The coating obtained has good hydrophilic and other properties.

  2. Switchable antifouling coatings and uses thereof

    Energy Technology Data Exchange (ETDEWEB)

    Denton, Michele L. Baca; Dirk, Shawn M.; Johnson, Ross Stefan

    2017-02-28

    The present invention relates to antifouling coatings capable of being switched by using heat or ultraviolet light. Prior to switching, the coating includes an onium cation component having antimicrobial and antibacterial properties. Upon switching, the coating is converted to a conjugated polymer state, and the cationic component is released with any adsorbed biofilm layer. Thus, the coatings herein have switchable and releasable properties. Methods of making and using such coatings are also described.

  3. Coating, Titanium Dioxide and Solar Cell

    OpenAIRE

    Yang, Aohan

    2011-01-01

    The objective of this bachelor’s thesis is to get basic ideas about coating and a deep understanding of properties of titanium dioxide pigments as well as their application and performance in solar electricity energy technology. This thesis consists of three main parts, eight chapters. The first part is about basic knowledge of coating and tests of coated paper. Coating pigments are generally introduced in the part. In the second part, coating additives are introduced in details from ...

  4. Graphene: corrosion-inhibiting coating.

    Science.gov (United States)

    Prasai, Dhiraj; Tuberquia, Juan Carlos; Harl, Robert R; Jennings, G Kane; Rogers, Bridget R; Bolotin, Kirill I

    2012-02-28

    We report the use of atomically thin layers of graphene as a protective coating that inhibits corrosion of underlying metals. Here, we employ electrochemical methods to study the corrosion inhibition of copper and nickel by either growing graphene on these metals, or by mechanically transferring multilayer graphene onto them. Cyclic voltammetry measurements reveal that the graphene coating effectively suppresses metal oxidation and oxygen reduction. Electrochemical impedance spectroscopy measurements suggest that while graphene itself is not damaged, the metal under it is corroded at cracks in the graphene film. Finally, we use Tafel analysis to quantify the corrosion rates of samples with and without graphene coatings. These results indicate that copper films coated with graphene grown via chemical vapor deposition are corroded 7 times slower in an aerated Na(2)SO(4) solution as compared to the corrosion rate of bare copper. Tafel analysis reveals that nickel with a multilayer graphene film grown on it corrodes 20 times slower while nickel surfaces coated with four layers of mechanically transferred graphene corrode 4 times slower than bare nickel. These findings establish graphene as the thinnest known corrosion-protecting coating.

  5. Polyester based hybrid organic coatings

    Science.gov (United States)

    Wang, Xiaojiang

    Polyesters are a class of polymers widely used in organic coatings applications. In this work, four types of organic coatings based on polyester polyols were prepared: UV-curable polyester/poly(meth)acrylate coatings, thermal curable polyester polyurethane-urea coatings, thermal curable non-isocyanate polyurethane coatings, and UV-curable non-isocyanate polyurethane coatings. Polyester/poly(meth)acrylate block copolymers are synthesized using a combination of polycondensation and Atom-Transfer Radical Polymerization (ATRP). All block copolymers are characterized by means of Nuclear Magnetic Resonance (NMR) and Gel Permeation Chromatography (GPC). In the case of unsaturated-polyester-based block copolymers the main chain double bond in the polyester backbone remains almost unaffected during ATRP. The unsaturated block copolymers are crosslinkable and can form networks upon photo-irradiation in the presence of a suitable photoinitiator. These copolymers might be interesting candidates for coatings with better overall properties than those based on neat polyesters. Thermal curable polyester polyol based Polyurethane-Urea (PUU) coatings were formulated using Partially Blocked HDI isocyanurate (PBH), Isophorone Diamine (IPDA), and polyester polyol. As a comparison, the polyurethane coatings (PU) without adding IPDA were also prepared. The mechanical and viscoelastic properties of the PUU and PU coating were investigated by using tensile test and Dynamic Mechanical Thermal Analyzer (DMTA). It was found that PUU coating exhibited higher crosslink density, Tg, tensile modulus and strength than the corresponding PU coating. Thermal curable non-isocyanate polyurethane coatings were prepared by using polyamine and cyclic carbonate terminated polyester. Cyclic carbonate terminated polyester was synthesized from the reaction of the carbon dioxide and epoxidized polyester which was prepared from the polyester polyol. The properties of the epoxidized and cyclic carbonate

  6. Self-Cleaning Glass Antireflection Films Prepared by Sol-Gel Method%溶胶-凝胶法制备玻璃基增透自清洁薄膜

    Institute of Scientific and Technical Information of China (English)

    方建辉; 韩国彬; 刘小文; 王乐; 杜云贵; 李建光

    2013-01-01

    The self-cleaning glass antireflection film was prepared on the surface of high borosilicate glass substrate by using TEOS and nanometer anatase type of titanium dioxide powder as sol-gel SiO2 -TiO2 composite raw materials and using Czochralski method.The effect of preparing technique on antireflection and photoinduced super hydrophilicity properties was investigated.The experiments show that the light transmittance of prepared sample increased about 3% at wavelength between 400nm and 800nm under light vertical incidence.After UV irradiation for a certain time,the water contact angle was ≤5° which exhibited the characteristic of photoinduced super hydrophilicity.%在酸催化体系中以正硅酸乙酯(TEOS)和纳米锐钛矿型二氧化钛粉末为SiO2-TiO2复合溶胶原料,采用提拉法在高硼硅玻璃基片表面制备出具有增透和自清洁功能的薄膜.研究了制备工艺对薄膜增透和光致超亲水性能的影响.制备的样品在400~ 800 nm波段,光线垂直入射时,透射率增加3%,紫外光照射一定时间后,样品对水接触角不超过5°,具有光致超亲水作用.

  7. Coating Carbon Fibers With Platinum

    Science.gov (United States)

    Effinger, Michael R.; Duncan, Peter; Coupland, Duncan; Rigali, Mark J.

    2007-01-01

    A process for coating carbon fibers with platinum has been developed. The process may also be adaptable to coating carbon fibers with other noble and refractory metals, including rhenium and iridium. The coated carbon fibers would be used as ingredients of matrix/fiber composite materials that would resist oxidation at high temperatures. The metal coats would contribute to oxidation resistance by keeping atmospheric oxygen away from fibers when cracks form in the matrices. Other processes that have been used to coat carbon fibers with metals have significant disadvantages: Metal-vapor deposition processes yield coats that are nonuniform along both the lengths and the circumferences of the fibers. The electrical resistivities of carbon fibers are too high to be compatible with electrolytic processes. Metal/organic vapor deposition entails the use of expensive starting materials, it may be necessary to use a furnace, and the starting materials and/or materials generated in the process may be hazardous. The present process does not have these disadvantages. It yields uniform, nonporous coats and is relatively inexpensive. The process can be summarized as one of pretreatment followed by electroless deposition. The process consists of the following steps: The surfaces of the fiber are activated by deposition of palladium crystallites from a solution. The surface-activated fibers are immersed in a solution that contains platinum. A reducing agent is used to supply electrons to effect a chemical reduction in situ. The chemical reduction displaces the platinum from the solution. The displaced platinum becomes deposited on the fibers. Each platinum atom that has been deposited acts as a catalytic site for the deposition of another platinum atom. Hence, the deposition process can also be characterized as autocatalytic. The thickness of the deposited metal can be tailored via the duration of immersion and the chemical activity of the solution.

  8. Kinetic regulation of coated vesicle secretion

    CERN Document Server

    Foret, Lionel

    2008-01-01

    The secretion of vesicles for intracellular transport often rely on the aggregation of specialized membrane-bound proteins into a coat able to curve cell membranes. The nucleation and growth of a protein coat is a kinetic process that competes with the energy-consuming turnover of coat components between the membrane and the cytosol. We propose a generic kinetic description of coat assembly and the formation of coated vesicles, and discuss its implication to the dynamics of COP vesicles that traffic within the Golgi and with the Endoplasmic Reticulum. We show that stationary coats of fixed area emerge from the competition between coat growth and the recycling of coat components, in a fashion resembling the treadmilling of cytoskeletal filaments. We further show that the turnover of coat components allows for a highly sensitive switching mechanism between a quiescent and a vesicle producing membrane, upon a slowing down of the exchange kinetics. We claim that the existence of this switching behaviour, also tri...

  9. Design of Polymer Coatings in Automotive Engines

    Institute of Scientific and Technical Information of China (English)

    LIAO Han-lin; ZHANG Ga; BORDES Jean-Michel; CHRISTIAN Coddet

    2004-01-01

    Driven by economical and ecological reasons, thermoplastics based coatings were more and more used in automotive engines. Two design concepts, flame spraying and serigraphy PEEK coatings on light metal substrate, were introduced in this paper. The friction and wear behavior of PEEK based coatings were investigated systematically. Coatings with different crystallinities can be obtained when cooling speed is controlled. Among three sprayed coatings considered with different crystallinities, the one with highest crystallinity exhibits best friction and wear behavior under dry sliding condition. Under lubricated sliding condition, however, the amorphous coating gives lower friction coefficient. The micron particles such as SiC,MoS2 and graphite in composite coatings can improve significantly the coating wear resistance and have a impact on coating friction behavior.

  10. Microstructure and Residual Stress of Shot Coating

    Science.gov (United States)

    Itoh, Yoshiyasu; Suyama, Shoko; Fuse, Toshiaki

    A shot coating process for metalizing at the surface of ceramics has been newly developed as the shot peening treatment. However, microstructure and residual stress of shot coatings, which have an important effect on the adherent strength of coatings and the strength of ceramic substrates, have not always been clarified. An experimental investigation on the microstructure and residual stress was carried out for the shot coating of aluminum on zinc-oxide substrate by comparison with the atmospheric plasma sprayed aluminum coatings. As a result, low porosity, low oxide content and flat surface could be obtained from the aluminum coatings formed by shot coating process in comparison with the atmospheric plasma sprayed aluminum coatings. Also, it was confirmed by the X-ray diffraction technique that the residual stress of shot coated aluminum over zinc-oxide substrate was high compressive in comparison with the atmospheric plasma spraying process.

  11. Sputtering process and apparatus for coating powders

    Science.gov (United States)

    Makowiecki, Daniel M.; Kerns, John A.; Alford, Craig S.; McKernan, Mark A.

    2002-01-01

    A process and apparatus for coating small particles and fibers. The process involves agitation by vibrating or tumbling the particles or fibers to promote coating uniformly, removing adsorbed gases and static charges from the particles or fibers by an initial plasma cleaning, and coating the particles or fibers with one or more coatings, a first coating being an adhesion coating, and with subsequent coatings being deposited in-situ to prevent contamination at layer interfaces. The first coating is of an adhesion forming element (i.e. W, Zr, Re, Cr, Ti) of a 100-10,000 .ANG. thickness and the second coating or final coating of a multiple (0.1-10 microns) being Cu or Ag, for example for brazing processes, or other desired materials that defines the new surface related properties of the particles. An essential feature of the coating process is the capability to deposit in-situ without interruption to prevent the formation of a contaminated interface that could adversely affect the coating adhesion. The process may include screening of the material to be coated and either continuous or intermittent vibration to prevent agglomeration of the material to be coated.

  12. Vertebrate extracellular preovulatory and postovulatory egg coats.

    Science.gov (United States)

    Menkhorst, Ellen; Selwood, Lynne

    2008-11-01

    Extracellular egg coats deposited by maternal or embryonic tissues surround all vertebrate conceptuses during early development. In oviparous species, the time of hatching from extracellular coats can be considered equivalent to the time of birth in viviparous species. Extracellular coats must be lost during gestation for implantation and placentation to occur in some viviparous species. In the most recent classification of vertebrate extracellular coats, Boyd and Hamilton (Cleavage, early development and implantation of the egg. In: Parkes AS (ed.), Marshall's Physiology of Reproduction, vol. 2, 3rd ed. London: Longmans, Green & Co; 1961:1-126) defined the coat synthesized by the oocyte during oogenesis as primary and the coat deposited by follicle cells surrounding the oocyte as secondary. Tertiary egg coats are those synthesized and deposited around the primary or secondary coat by the maternal reproductive tract. This classification is difficult to reconcile with recent data collected using modern molecular biological techniques that can accurately establish the site of coat precursor synthesis and secretion. We propose that a modification to the classification by Boyd and Hamilton is required. Vertebrate egg coats should be classed as belonging to the following two broad groups: the preovulatory coat, which is deposited during oogenesis by the oocyte or follicle cells, and the postovulatory coats, which are deposited after fertilization by the reproductive tract or conceptus. This review discusses the origin and classification of vertebrate extracellular preovulatory and postovulatory coats and illustrates what is known about coat homology between the vertebrate groups.

  13. Coating Microstructure-Property-Performance Issues

    Energy Technology Data Exchange (ETDEWEB)

    Terry C. Totemeier; Richard N. Wright

    2005-05-01

    Results of studies on the relationships between spray parameters and performance of thermally-sprayed intermetallic coatings for high-temperature oxidation and corrosion resistance are presented. Coating performance is being assessed by corrosion testing of free-standing coatings, thermal cycling of coating substrates, and coating ductility measurement. Coating corrosion resistance was measured in a simulated coal combustion gas environment (N2-CO-CO2-H2O-H2S) at temperatures from 500 to 800°C using thermo-gravimetric analysis (TGA). TGA testing was also performed on a typical ferritic-martensitic steel, austenitic stainless steel, and a wrought Fe3Al-based alloy for direct comparison to coating behavior. FeAl and Fe3Al coatings showed corrosion rates slightly greater than that of wrought Fe3Al, but markedly lower than the steels at all temperatures. The corrosion rates of the coatings were relatively independent of temperature. Thermal cycling was performed on coated 316SS and nickel alloy 600 substrates from room temperature to 800°C to assess the relative effects of coating microstructure, residual stress, and thermal expansion mismatch on coating cracking by thermal fatigue. Measurement of coating ductility was made by acoustic emission monitoring of coated 316SS tensile specimens during loading.

  14. Diffusion Barrier Coating System and Oxidation Behavior of Coated Alloys

    Institute of Scientific and Technical Information of China (English)

    T.NARITA

    2009-01-01

    @@ 1 Introduction Research into the formation of Re-based alloys is in progress in our laboratory to provide a diffusion barrier layer between heat-resistant alloys and Al reservoir layers, which assist in the formation and maintenance a protective Al2O3 scale for long periods. Coatings with a two-layered structure comprised of inner Re-based alloy layer and outer β-NiAl layer with or without Pt addition were successfully formed on various heat resistant alloys such as Ni-based singlecrystal superalloys, Ni-based heat resistant alloys, NiMo based alloy, Ni-Cr based alloy, and Fe-based alloys. The duplex layer coating proposed is generally termed a diffusion barrier coating system; DBC system.

  15. Testing and Evaluation of Multifunctional Smart Coatings

    Science.gov (United States)

    Buhrow, Jerry; Li, Wenyan; Jolley, Scott; Calle, Luz M.; Pearman, Benjamin; Zhang, Xuejun

    2015-01-01

    A smart coating system, based on pH sensitive microcontainers (microparticles and microcapsules) has been developed. Various corrosion inhibitors have been encapsulated and incorporated into commercial and formulated coatings to test the functionality imparted on the coating by the incorporation of the inhibitor microcontainers. Coated carbon steel and aluminum alloy panels were tested using salt immersion, salt fog, and coastal atmospheric exposure conditions. This paper provides the details on coating sample preparation, evaluation methods, as well as test results of the inhibiting function of smart coatings.

  16. Chromate conversion coatings and their current application

    Directory of Open Access Journals (Sweden)

    P. Pokorny

    2016-04-01

    Full Text Available This paper describes formation, composition and possible production technologies of application chromate coatings. Summation of common examples of applications of these coatings in corrosion protection of metals and alloys is provided. Individual chromate coatings are divided by their dominant anions either with CrVI or CrIII. Restrictions of chromate coatings with dominantly CrVI and related toxicity of hexavalent chromium is discussed in detail. In conclusion, examples of both chromium and other, alternative coatings are summed up. Application of these coatings as a protection for concrete hot-dip galvanized reinforcement is also reviewed.

  17. Mixed zirconia calcium phosphate coatings for dental implants: Tailoring coating stability and bioactivity potential

    Energy Technology Data Exchange (ETDEWEB)

    Pardun, Karoline [University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen (Germany); Treccani, Laura, E-mail: treccani@uni-bremen.de [University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen (Germany); Volkmann, Eike [University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen (Germany); Streckbein, Philipp [University Hospital, Justus-Liebig-University Giessen, Department of Cranio-Maxillo-Facial Surgery, Klinikstrasse 33, 35385 Giessen (Germany); Heiss, Christian [University Hospital of Giessen-Marburg, Department of Trauma Surgery, Rudolf-Buchheim-Strasse 7, 35385 Giessen, Germany, (Germany); Laboratory of Experimental Surgery, Kerkraderstrasse 9, 35392 Giessen (Germany); Destri, Giovanni Li; Marletta, Giovanni [Laboratory for Molecular Surfaces and Nanotechnology (LAMSUN), Department of Chemistry, University of Catania and CSGI, Viale A. Doria 6, 95125 Catania (Italy); Rezwan, Kurosch [University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen (Germany)

    2015-03-01

    Enhanced coating stability and adhesion are essential for long-term success of orthopedic and dental implants. In this study, the effect of coating composition on mechanical, physico-chemical and biological properties of coated zirconia specimens is investigated. Zirconia discs and dental screw implants are coated using the wet powder spraying (WPS) technique. The coatings are obtained by mixing yttria-stabilized zirconia (TZ) and hydroxyapatite (HA) in various ratios while a pure HA coating served as reference material. Scanning electron microscopy (SEM) and optical profilometer analysis confirm a similar coating morphology and roughness for all studied coatings, whereas the coating stability can be tailored with composition and is probed by insertion and dissections experiments in bovine bone with coated zirconia screw implants. An increasing content of calcium phosphate (CP) resulted in a decrease of mechanical and chemical stability, while the bioactivity increased in simulated body fluid (SBF). In vitro experiments with human osteoblast cells (HOB) revealed that the cells grew well on all samples but are affected by dissolution behavior of the studied coatings. This work demonstrates the overall good mechanical strength, the excellent interfacial bonding and the bioactivity potential of coatings with higher TZ contents, which provide a highly interesting coating for dental implants. - Highlights: • Different ratios of zirconia (TZ) and calcium phosphate (CP) were deposited on zirconia substrates. • Enhancement of TZ content in mixed coatings increased coating stability. • Enhancement of CP content in mixed coatings increased bioactivity. • All tested coating compositions were non-toxic.

  18. Dielectric Coatings for IACT Mirrors

    CERN Document Server

    Förster, A; Chadwick, P; Held, M

    2013-01-01

    Imaging Atmospheric Cherenkov Telescopes for very-high energy gamma-ray astronomy need mirror with high reflectance roughly in the wavelength between 300 and 550 nm. The current standard reflective layer of such mirrors is aluminum. Being permanently exposed to the environment they show a constant degradation over the years. New and improved dielectric coatings have been developed to enhance their resistance to environmental impact and to extend their possible lifetime. In addition, these customized coatings have an increased reflectance of over 95% and are designed to significantly lower the night-sky background contribution. The development of such coatings for mirrors with areas up to 2 m2 and low application temperatures to suite the composite materials used for the new mirror susbtrates of the Cherenkov Telescope Array (CTA) and the results of extensive durability tests are presented.

  19. Self-Healing anticorrosive coatings

    DEFF Research Database (Denmark)

    Nesterova, Tatyana

    Self-healing anticorrosive coatings are multi-component so-called smart materials, which have been proposed as a way to long-lasting corrosion protection of steel structures. The presently most promising technology route is based on microcapsules, filled with active healing agents, and has been...... the focus of this work. The microcapsules consist of a solid polymeric shell and a liquid core material. When a microcrack, originating from internal stress or a physical damage, propagates through the coating, the microcapsules rupture and release healing agents, which flow to the fracture plane due...... to capillary forces. The healing agents then start to react, form a polymer network, and =glue‘ the crack. The approach has been applied to development of an epoxy-based self-healing anticorrosive coating for above water heavy duty corrosion protection. Emphasis has been on investigation of practical issues...

  20. Clean diffusion coatings by chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Warnes, B.M.; Punola, D.C. [Howmet Thermatech Coatings, Whitehall, MI (United States)

    1997-10-01

    An experimental program was undertaken to identify diffusion coating impurities introduced by standard aluminizing processes and to evaluate the impact of those impurities on oxidation resistance of the resultant Pt aluminide coating. IN-738 tabs and foils were platinum-electroplated, and then aluminized using three different processes: high-activity pack cementation, high-activity CVD and low-activity CVD. The results suggest that aluminizing processes which involve aluminum bearing alloys in the coating retort with H{sub 2} or H{sub 2}/HCl gas at high temperature can contaminate the diffusion coating during deposition. CVD low-activity aluminizing (coating gas generated at low temperature outside the coating chamber from 99.999% Al) did not introduce any coating impurities. In addition, the data indicates that harmful impurities from the IN-738 substrate (sulfur, boron and tungsten) and the electroplating process (phosphorus) were removed from the coating during deposition. The CVD low-activity Pt aluminide coating was the `cleanest` in the study, and it exhibited the best high-temperature oxidation resistance of the coatings considered. It can be concluded that trace elements in diffusion coatings from the superalloy substrate and/or the aluminizing process can adversely effect the oxidation resistance of those coatings, and that CVD low-activity aluminizing yields cleaner coatings than other commercially available aluminizing techniques. (orig.) 10 refs.

  1. Nano-Ceramic Coated Plastics

    Science.gov (United States)

    Cho, Junghyun

    2013-01-01

    Plastic products, due to their durability, safety, and low manufacturing cost, are now rapidly replacing cookware items traditionally made of glass and ceramics. Despite this trend, some still prefer relatively expensive and more fragile ceramic/glassware because plastics can deteriorate over time after exposure to foods, which can generate odors, bad appearance, and/or color change. Nano-ceramic coatings can eliminate these drawbacks while still retaining the advantages of the plastic, since the coating only alters the surface of the plastic. The surface coating adds functionality to the plastics such as self-cleaning and disinfectant capabilities that result from a photocatalytic effect of certain ceramic systems. These ceramic coatings can also provide non-stick surfaces and higher temperature capabilities for the base plastics without resorting to ceramic or glass materials. Titanium dioxide (TiO2) and zinc oxide (ZnO) are the candidates for a nano-ceramic coating to deposit on the plastics or plastic films used in cookware and kitchenware. Both are wide-bandgap semiconductors (3.0 to 3.2 eV for TiO2 and 3.2 to 3.3 eV for ZnO), so they exhibit a photocatalytic property under ultraviolet (UV) light. This will lead to decomposition of organic compounds. Decomposed products can be easily washed off by water, so the use of detergents will be minimal. High-crystalline film with large surface area for the reaction is essential to guarantee good photocatalytic performance of these oxides. Low-temperature processing (nano-ceramic coatings (TiO2, ZnO) on plastic materials (silicone, Teflon, PET, etc.) that can possess both photocatalytic oxide properties and flexible plastic properties. Processing cost is low and it does not require any expensive equipment investment. Processing can be scalable to current manufacturing infrastructure.

  2. Matching Performance among Visible and near Infrared Coating, Low Infrared Emitting Coating and Microwave Absorbing Coating

    Institute of Scientific and Technical Information of China (English)

    XIE Guohua; ZHANG Zuoguang; WU Ruibin

    2005-01-01

    The matching performance among the visible and near infrared conting, the low infrared emitting coating and the microwave absorbing coating was investigated. Experimental results shaw that the resulting material is characteristic of wideband effect ranging from the visible, near infrared and 3-5μm, 8- 14 μm infrared portion of the spectrum, as well as the radar region from 8 to 18 GHz when these three materials form a layerstructure material system. The microwave absorbing ability of material is hardly changed. The resonance peak moves towards lower frequency as the thickness of the visible, near infrared coating and the low infrared emitting coating increases. This problem can be resolved by controlling the thickness of the material. On the other hand,the infrared emissivity ε of the material system increases as the thickness of the visible, near infrared coating increases. This can be resolved by increasing infrared transparency of the visible and near infrared topcoating or controlling its thickness. The experimental resulting material system has spectral reflection characteristics in visible and near infrared regions that are similar to those of the natural bnckground.

  3. Protective Coatings for Aluminum Torpedoes

    Science.gov (United States)

    1983-06-01

    dhesion test, the entire coating sys- tea was removed, leaving the substrate exposed. During the impact tests, the 37 coating debonded within the...M tree ot detects in mawnai or dccrqva~e Weyesi aoicti cr Wi15 ryafsX-_ oa ifani w Aobgaon -rlefl CrS~ t1 hi~~~~~~~~ cadsoie.xrn a gab on srd... Eczema , rash Eye contact: Fodwith stemof water Inhalation Fresh Air Ingestion Call Physician for advice. DO NOT induce vomiting Skin contact Wash

  4. Coated carbon nanotube array electrodes

    Science.gov (United States)

    Ren, Zhifeng; Wen, Jian; Chen, Jinghua; Huang, Zhongping; Wang, Dezhi

    2008-10-28

    The present invention provides conductive carbon nanotube (CNT) electrode materials comprising aligned CNT substrates coated with an electrically conducting polymer, and the fabrication of electrodes for use in high performance electrical energy storage devices. In particular, the present invention provides conductive CNTs electrode material whose electrical properties render them especially suitable for use in high efficiency rechargeable batteries. The present invention also provides methods for obtaining surface modified conductive CNT electrode materials comprising an array of individual linear, aligned CNTs having a uniform surface coating of an electrically conductive polymer such as polypyrrole, and their use in electrical energy storage devices.

  5. Thin Films for Coating Nanomaterials

    Institute of Scientific and Technical Information of China (English)

    S.M.Mukhopadhyay; P.Joshi; R.V.Pulikollu

    2005-01-01

    For nano-structured solids (those with one or more dimensions in the 1-100 nm range), attempts of surface modification can pose significant and new challenges. In traditional materials, the surface coating could be several hundreds nanometers in thickness, or even microns and millimeters. In a nano-structured material, such as particle or nanofibers, the coating thickness has to be substantially smaller than the bulk dimensions (100 nm or less), yet be durable and effective. In this paper, some aspects of effective nanometer scale coatings have been discussed. These films have been deposited by a non-line of sight (plasma)techniques; and therefore, they are capable of modifying nanofibers, near net shape cellular foams, and other high porosity materials. Two types of coatings will be focused upon: (a) those that make the surface inert and (b) those designed to enhance surface reactivity and bonding. The former has been achieved by forming 1-2 nm layer of -CF2- (and/or CF3) groups on the surface, and the latter by creating a nanolayer of SiO2-type compound. Nucleation and growth studies of the plasma-generated film indicate that they start forming as 2-3 nm high islands that grow laterally, and eventually completely cover the surface with 2-3nm film. Contact angle measurements indicate that these nano-coatings are fully functional even before they have achieved complete coverage of 2-3 nm. They should therefore be applicable to nano-structural solids.This is corroborated by application of these films on vapor grown nanofibers of carbon, and on graphitic foams. Coated and uncoated materials are infiltrated with epoxy matrix to form composites and their microstructure, as well as mechanical behaviors are compared. The results show that the nano-oxide coating can significantly enhance bond formation between carbon and organic phases, thereby enhancing wettability,dispersion, and composite behavior. The fluorocarbon coating, as expected, reduces bond formation, and

  6. Corrosion-resistant coating development

    Energy Technology Data Exchange (ETDEWEB)

    Stinton, D.P.; Kupp, D.M.; Martin, R.L. [Oak Ridge National Lab., TN (United States)

    1997-12-01

    SiC-based heat exchangers have been identified as the prime candidate material for use as heat exchangers in advanced combined cycle power plants. Unfortunately, hot corrosion of the SiC-based materials created by alkali metal salts present in the combustion gases dictates the need for corrosion-resistant coatings. The well-documented corrosion resistance of CS-50 combined with its low (and tailorable) coefficient of thermal expansion and low modulus makes CS-50 an ideal candidate for this application. Coatings produced by gelcasting and traditional particulate processing have been evaluated.

  7. RECENT TECHNIQUES OF PHARMACEUTICAL SOLVENTLESS COATING: A REVIEW

    Directory of Open Access Journals (Sweden)

    Shital Dhuppe , S.S. Mitkare*, D.M. Sakarkar

    2012-07-01

    Full Text Available The coating of solid pharmaceutical dosage forms began in the 9th century B. C., with the Egyptians. Conventional coating techniques are based on solvents or water. Solventless coatings are alternative technique of coating. In solventless coating, the coating material is directly spread on the core and then it is cured by special method to form coat. Solventless coating avoids the use of water or it reduces to very small amounts with respect to the coating material hence it overcomes the limitations of conventional coating such as need for time, energy consuming, drying steps and the most important drug stability issues. A variety of solventless coating approaches are described in this review as powder coating, hot melt coating, supercritical fluid coating, magnetically assisted impaction coating, Plasma enhanced chemical vapor deposition. This review summarizes basic principle and process of the coating techniques.

  8. Preparation and characterization of optical antifogging nano-coating%纳米光学防雾膜的制备与表征

    Institute of Scientific and Technical Information of China (English)

    李坚; 刘佳一; 张阳德

    2010-01-01

    Objective To prepare and test a hydrophilic antifogging nano -coating with favourable stability and antireflective characteristics. Methods Hydrophilic antifogging coating consisted of cationic polyacrylamide (CPAM), sodium silicate and polyacrylic acid (PAA). To obtain a stable multilayer film, the coatings were filmed by layer-by-layer coating method followed with a thermal torrefraction process. The material particle size was measured by a laser particle sizer, lens transmittance prior to and after coating was evaluated by ultraviolet spectrophotometer, coating hydrophilicity was tested by contact angle meter, and coating hardness was determined by pencil test. Results The coating particle size was about (145.0±15.6)nm. In the light spectrum between 400 nm and 800 nm, the transmittance of the coated optical lens was higher than that of the uncoated one, the transmittance peaked at 550 nm wavelength which reached 92.2% . Water drop dispersed completely 470 ms after it contacted with the coating surface. The coating hardness was higher than 3 H. Conclusion The antifogging coating prepared by layer -by -layer method forms stable film structure after thermal torrefaction and improves lens hydrophilicity and transmittence.%目的 制备并测试具有良好稳定性的增透、亲水纳米防雾膜.方法 将阳离子聚丙烯酰胺、硅酸钠和聚丙烯酸通过逐层涂膜法涂覆在透明光学基材表面,经高温烘干得到稳定的聚丙烯酰胺-硅酸钠和聚丙烯酸亲水防雾膜,并使用激光粒度分析仪测定材料粒径大小,使用扫描电子显微镜观察镜片表面形貌,使用紫外分光光度计对镜片镀膜前后透光率进行比较,使用接触角测试仪检测膜层亲水性,使用铅笔测定法测量涂膜硬度.结果 实验中所用化学材料聚丙烯酰胺-硅酸钠粒径分布约(145.0±15.6)nm,在400~800 nm光波段内,涂膜后的光学镜片比原镜片的透光率稍高,在550 nm处透光率达到最大值92

  9. Novel alginate based coatings on Mg alloys

    Energy Technology Data Exchange (ETDEWEB)

    Sangeetha, K.; Roy, Abhijit [Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Singh, Satish [Department of Chemical Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Lee, Boeun [Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Kumta, Prashant N., E-mail: pkumta@pitt.edu [Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Department of Chemical Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Center for Craniofacial Regeneration, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Center for Complex Engineered Multifunctional Materials, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, PA 15261 (United States)

    2011-12-15

    Coatings on yttrium doped magnesium (Mg4Y) alloy substrates were prepared using alginate hydrogels by dip coating method to improve the surface bioactive properties of the substrate. Furthermore, composite coatings containing nano-sized calcium phosphate corresponding to hydroxyapatite (HA) phase entrapped within alginate hydrogel were also synthesized on the Mg4Y substrates. Surface characteristics of these coated substrates have been investigated using FTIR-ATR, SEM and EDS. The results show that the coatings with alginate alone are not stable in vitro; however, incorporation of NanoCaPs slightly improves the stability of these coatings. In addition, these composite coatings showed cell attachments with fibronectin incorporation. These results indicate that alginate hydrogels have the potential to be used as bioactive coating materials for different biofunctional applications.

  10. Improving thermal barrier coatings by laser remelting.

    Science.gov (United States)

    Múnez, C J; Gómez-García, J; Sevillano, F; Poza, P; Utrilla, M V

    2011-10-01

    Thermal barrier coatings are extensively used to protect metallic components in applications where the operating conditions include aggressive environment at high temperatures. These coatings are usually processed by thermal spraying techniques and the resulting microstructure includes thin and large splats, associated with the deposition of individual droplets, with porosity between splats. This porosity reduces the oxidation and corrosion resistance favouring the entrance of aggressive species during service. To overcome this limitation, the top coat could be modified by laser glazing reducing surface roughness and sealing open porosity. ZrO2(Y2O3) top coat and NiCrAlY bond coating were air plasma sprayed onto an Inconel 600 Ni base alloy. The top coat was laser remelted and a densified ceramic layer was induced in the top surface of the ceramic coating. This layer inhibited the ingress of aggressive species and delayed bond coat oxidation.

  11. Durable Dust Repellent Coating for Metals Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Durable Dust Repellent Coating (DDRC) consists of nano-phase silica, titania, or other oxide coatings to repel dust in a vacuum environment over a wide range of...

  12. STUDY ON VISCOELASTIC BEHAVIOR OF PAPER COATING

    Institute of Scientific and Technical Information of China (English)

    Heng Zhang; Kefu Chen; Rendang Yang

    2004-01-01

    The flow behavior of paper coating is critical to the coating operation. In this work, the influence of the added agents on the flow behavior and the viscoelastic behavior is investigated using rheometer in steady and dynamic oscillatory modes.

  13. Development of coatings for fusion power applications

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D.L. E-mail: dalesmith@anl.gov; Konys, J.; Muroga, T.; Evitkhin, V

    2002-12-01

    Coatings have been proposed as the solution to critical materials constraints for most of the blanket concepts under development for fusion power applications. However, the international programs on coating development are focused primarily on electrically insulating coatings to mitigate the magneto-hydrodynamic pressure drop in self-cooled lithium/vanadium blanket concepts, and on tritium permeation barriers to reduce tritium permeation from Pb-Li into the water coolant in water-cooled Pb-Li concepts. Emphasis of the insulator coating development is on CaO and AlN coatings formed on vanadium alloys either in situ in lithium or by vapor deposition processes. The tritium barrier coating development is focused on Al{sub 2}O{sub 3} formed on aluminized martensitic steels by several processes. This paper presents an overview of the fundamental materials issues associated with the various coatings and the status of coating development for the various applications.

  14. Genetics Home Reference: Coats plus syndrome

    Science.gov (United States)

    ... Coats disease plus abnormalities of the brain, bones, gastrointestinal system, and other parts of the body. Coats disease ... life-threatening complications including abnormal bleeding in the gastrointestinal tract, high blood pressure in the vein that supplies ...

  15. Stress and structure development in polymeric coatings

    Science.gov (United States)

    Vaessen, Diane Melissa

    2002-09-01

    The main goal of this research is to measure the stress evolution in various polymer coating systems to establish the mechanisms responsible for stress development, stress relaxation, and defect formation. Investigated systems include ultraviolet (UV)-curable coatings, dense and porous coatings from polymer solutions, and latex coatings. Coating stress was measured using a controlled environment stress apparatus based on a cantilever deflection principle. For acrylate coatings, it was found that by cycling a UV-lamp on and off, keeping the total dose constant, coating stress was lowered by 60% by decreasing the cycle period. A stress minimum was also found to exist for a given dose of radiation. The lower stress is attributed to stress relaxation and/or slower reaction during dark periods. A viscoelastic stress model of this process was formulated and predicted stress values close to those observed experimentally. During drying of cellulose acetate (CA) coatings cast in acetone, final stress increased from 10 to 45 MPa as coating thickness decreased from 60 to 10 mum. This thickness dependent coating stress for a solvent-cast polymer coating is a new finding and is attributed to (1) less shrinkage in thicker coatings due to more trapped solvent (from skinning) and (2) greater amounts of polymer stress relaxation in thicker coatings. For porous CA coatings prepared by dry-cast phase separation, final in-plane stresses ranged from 20 MPa for coatings containing small pores (˜1 mum) to 5 MPa for coatings containing small pores and macrovoids (˜200 mum). For these coatings, a small amount of stress relaxation occurs due to capillary pressure relief. A stress plateau for the macrovoid-containing coating is likely caused by stress-induced rupture of the polymer-rich phase. Measured stress in pigment-free latex coatings was much lower (˜0.3 MPa) than UV-curable and solvent-cast polymer coatings and was found to increase with increasing latex glass transition

  16. Microneedle Coating Techniques for Transdermal Drug Delivery

    OpenAIRE

    Rita Haj-Ahmad; Hashim Khan; Muhammad Sohail Arshad; Manoochehr Rasekh; Amjad Hussain; Susannah Walsh; Xiang Li; Ming-Wei Chang; Zeeshan Ahmad

    2015-01-01

    Drug administration via the transdermal route is an evolving field that provides an alternative to oral and parenteral routes of therapy. Several microneedle (MN) based approaches have been developed. Among these, coated MNs (typically where drug is deposited on MN tips) are a minimally invasive method to deliver drugs and vaccines through the skin. In this review, we describe several processes to coat MNs. These include dip coating, gas jet drying, spray coating, electrohydrodynamic atomisat...

  17. Cirrus Dopant Nano-Composite Coatings

    Science.gov (United States)

    2014-11-01

    Inorganic Nano-particles • Ti • Zr • Al • Zn • Yr • Si Coatings • Au • Ag • Sn • Cu • Zn • Ni • NiB • NiCo • NiP cirrus Broadened...1000 1200 HARDNESS (HV) MICROHARDNESS - ELECTROLESS NIP STANDARD COATING TI DOPED COATING ZR DOPED COATING ↑74% Standard DC NiB Cirrus DC NiB 15

  18. Deposition and Coating Properties on CVD Tungsten

    Institute of Scientific and Technical Information of China (English)

    DU Ji-hong; LI Zheng-xiang; LIU Gao-jian; ZHOU Hui-Huang; CHUN liang

    2004-01-01

    Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.

  19. RECENT TECHNIQUES OF PHARMACEUTICAL SOLVENTLESS COATING: A REVIEW

    OpenAIRE

    Shital Dhuppe , S.S. Mitkare*, D.M. Sakarkar

    2012-01-01

    The coating of solid pharmaceutical dosage forms began in the 9th century B. C., with the Egyptians. Conventional coating techniques are based on solvents or water. Solventless coatings are alternative technique of coating. In solventless coating, the coating material is directly spread on the core and then it is cured by special method to form coat. Solventless coating avoids the use of water or it reduces to very small amounts with respect t...

  20. Pipeline coating comparison methods for northern pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Singh, P. [Shaw Pipe Protection, Calgary, AB (Canada); Purves, G.A. [Cimarron Engineering Ltd., Calgary, AB (Canada)

    2004-07-01

    Two high-quality pipe coatings designed for northern environments were compared for their relative costs and suitability for the conditions that will be encountered in the field. Coating selection should consider local conditions to achieve the optimum life-cycle costs for the system. Some of the key factors affecting the integrity of the protective coating on a pipe include the effects of cold temperature and soil types. In this study, both Fusion Bonded Epoxy (FBE) and High Performance Composite Coatings (HPCC) were evaluated for an entire pipeline installation in a northern environment, from the coating plant to the pipe trench. The evaluation focused on the advantages of better abrasion resistance of the HPCC coating. This was compared against the incremental cost of HPCC coating over FBE on large diameter NPS 30 to NPS 48 pipelines. The following parameters influenced the choice of coating: storage, transportation and handling; bending ability under cold weather conditions; pipe installation and backfilling; weld joint coatings; coating repair and cathodic protection and pipeline integrity. Some of the construction costs that are indirectly affected by the choice of pipe coating include right-of-way preparation and restoration; trenching; supervision, service and downtime and specialist crossings. It was concluded that HPCC has better resistance to abrasion than FBE and is more flexible in extremely cold temperatures. Standard FBE is about 10 per cent less expensive than HPCC. In general HPCC will require less coating protection than FBE, depending on site conditions. 3 refs., 18 tabs., 8 figs.

  1. Latest Developments in PVD Coatings for Tooling

    Directory of Open Access Journals (Sweden)

    Gabriela Strnad

    2010-06-01

    Full Text Available The paper presents the recent developments in the field of PVD coating for manufacturing tools. A review of monoblock, multilayer, nanocomposite, DLC and oxinitride coatings is discussed, with the emphasis on coatings which enables the manufacturers to implement high productivity processes such as high speed cutting and dry speed machining.

  2. “m=1” coatings

    DEFF Research Database (Denmark)

    Cooper-Jensen, C.; Klinkby, Esben Bryndt; Beaucour, J.

    chemical hazard after manufacture is Be dust if the sample is destroyed. We have a sample of 276 nm Be coated on a Si wafer for these tests. Diamond Like Carbon (DLC) coatings with 99% sp3 bindings (meaning it is very close to diamond) are made commercially using CVD techniques. In the coating...

  3. Absorptive coating for aluminum solar panels

    Science.gov (United States)

    Desmet, D.; Jason, A.; Parr, A.

    1979-01-01

    Method for coating forming coating of copper oxide from copper component of sheet aluminum/copper alloy provides strong durable solar heat collector panels. Copper oxide coating has solar absorption characteristics similar to black chrome and is much simpler and less costly to produce.

  4. Deposition and Investigation of Hydrophobic Coatings

    Directory of Open Access Journals (Sweden)

    Safonov Aleksey

    2015-01-01

    Full Text Available The fluoropolymer coatings of different morphologies are deposited by the HWCVD (Hot Wire CVD method. The effect of activator filament temperature on the structure of fluoropolymer coating is shown. The results of studying the hydrophobic fluoropolymer coatings with different structures, deposited by the HWCVD method, are presented.

  5. Supra-amphiphilic transparent mesoporous silica coating

    Institute of Scientific and Technical Information of China (English)

    MA Jin; YANG Zhenglong; QU Xiaozhong; YANG Zhenzhong

    2006-01-01

    Transparent mesoporous silica coatings were achieved by conventional sol-gel process. The obtained coatings display permanent supraamphiphilicity, transparent appearance and good wetting property with very fast spread rate. Incorporation of functional materials such as crystalline titania nanoparticles into the coatings was also carried out without affecting the transparency and supraamphiphilicity.

  6. Superhard nano-multilayers and nanocomposite coatings

    Institute of Scientific and Technical Information of China (English)

    BAI Xiaoming; ZHENG Weitao; AN Tao

    2005-01-01

    This paper reviews the recent development of nano-multilayers and nanocomposite coatings. The hardening mechanisms and design of hard coating are discussed in details. Recent research on Ti/TiN and nitride/nitride multilayer, Ti-Si-N and Ti-Al-Si-N nanocomposite coatings is described, and the perspectives of the related research are proposed.

  7. Natural-oxide solar-collector coatings

    Science.gov (United States)

    Krupnick, A. C.; Roberts, M. L.; Sharpe, M. H.

    1979-01-01

    Optically selective coatings for solar collectors are produced by thermally treating stainless steel in furnace after series of cleaning and soaking operations. Coatings have withstood 18-month exposure tests at 100 percent relative humidity and temperatures of 95 F. Room temperature coatings are valuable as they are inexpensive to produce, highly production oriented, and environmentally stable.

  8. Applicability of coatings to control metal dusting

    NARCIS (Netherlands)

    Hermse, C.G.M.; Wortel, J.C. van

    2009-01-01

    We have performed a long term comparative study between five wrought and three centricast materials, both as-is, and in coated condition. Two commercially available coatings were applied to each different alloy. One coating was aluminum based with a chromium rich intermediate layer. The other coatin

  9. Chemical vapor deposition of mullite coatings

    Science.gov (United States)

    Sarin, Vinod; Mulpuri, Rao

    1998-01-01

    This invention is directed to the creation of crystalline mullite coatings having uniform microstructure by chemical vapor deposition (CVD). The process comprises the steps of establishing a flow of reactants which will yield mullite in a CVD reactor, and depositing a crystalline coating from the reactant flow. The process will yield crystalline coatings which are dense and of uniform thickness.

  10. Moisture in organic coatings - a review

    NARCIS (Netherlands)

    Wel, G.K. van der; Adan, O.C.G.

    1999-01-01

    A review is given on transport and equilibrium sorption of moisture in polymer films and organic coatings. Polymeric material forms the continuous phase of a coating and is therefore important for transport properties. Besides polymer, coatings consist of pigments and fillers and various additives,

  11. Microstructure and properties of high emissivity coatings

    Institute of Scientific and Technical Information of China (English)

    Zhigang Dan; Daqiang Cang; Huimin Zhou; Hao Bai; Yanbin Zong

    2008-01-01

    A new coating on lining in industrial furnace for energy saving has been developed. Properties and microstructure of the coatings were revealed by emissivity instrument, X-ray diffraction (XRD), transmission electron microscope (TEM) and scanning electron microscope (SEM), respectively. The result indicates that the emissivity of coatings is higher than 0.90 and the thickness of coatings is about 200 μm. ZrO2, Cr2O3 and SiC in the coating benefit practical applications of coatings at high temperature with du-rable high emissivity and the continuous structure between the coatings and the substrate makes the coatings high cohesion and ex-cellent adhesion for both specimens with and without sintering at high temperature. Result fi'om laboratory experiment shows that the heating speed of specimen with coating is higher than that of controlled specimen and the temperature increases 30℃ during the heating. The average temperature drop of specimen with coatings has a 13.5% improvement in the cooling speed. The application of coatings on the checker brick in a blast furnace of 1750 m3 indicates that the coating causes the blast temperature to an average in-crease of 28℃, reduces the fluctuation of blast temperature before the blowing-in and leads to a fuel saving of 10% approximately.

  12. Moisture transport in coated plaster

    NARCIS (Netherlands)

    Goossens, E.L.J.; Van der Spoel, W.H.; Bancken, E.L.J.

    2001-01-01

    In the framework of the research project: 'Water balance of water-borne paint systems on plaster substrates in relation to fungal growth', a study is carried out to moisture transport mechanisms in coated gypsum plaster. In this contribution, the set-up of the study is described. Besides a descripti

  13. Polymer-coated quantum dots

    NARCIS (Netherlands)

    Tomczak, Nikodem; Liu, Rongrong; Vancso, Julius G.

    2013-01-01

    Quantum Dots (QDs) are semiconductor nanocrystals with distinct photophysical properties finding applications in biology, biosensing, and optoelectronics. Polymeric coatings of QDs are used primarily to provide long-term colloidal stability to QDs dispersed in solutions and also as a source of addit

  14. Mechanically reliable scales and coatings

    Energy Technology Data Exchange (ETDEWEB)

    Tortorelli, P.F.; Alexander, K.B. [Oak Ridge National Lab., TN (United States)

    1995-06-01

    In many high-temperature fossil energy systems, corrosion and deleterious environmental effects arising from reactions with reactive gases and condensible products often compromise materials performance and, as a consequence, degrade operating efficiencies. Protection of materials from such reactions is best afforded by the formation of stable surface oxides (either as deposited coatings or thermally grown scales) that are slowly reacting, continuous, dense, and adherent to the substrate. However, the ability of normally brittle ceramic films and coatings to provide such protection has long been problematical, particularly for applications involving numerous or severe high-temperature thermal cycles or very aggressive (for example, sulfidizing) environments. A satisfactory understanding of how scale and coating integrity and adherence are improved by compositional, microstructural, and processing modifications is lacking. Therefore, to address this issue, the present work is intended to define the relationships between substrate characteristics (composition, microstructure, and mechanical behavior) and the structure and protective properties of deposited oxide coatings and/or thermally grown scales. Such information is crucial to the optimization of the chemical, interfacial, and mechanical properties of the protective oxides on high-temperature materials through control of processing and composition and directly supports the development of corrosion-resistant, high-temperature materials for improved energy and environmental control systems.

  15. Heparin-Coated Coronary Stents.

    Science.gov (United States)

    van Der Giessen WJ; van Beusekom HM; Larsson; Serruys

    1999-09-01

    The development of the heparin-coated (HC)-stent should be viewed against the backdrop of the early unfavorable results with noncoated stents in the pre-intravascular ultrasound and pre-ticlopidine era. Notwithstanding, results of pilot and randomized trials show a surprisingly low incidence of (sub)acute stent thrombosis under challenging circumstances, such as acute coronary syndromes. Considering the quite low incidence of early complications with noncoated second-generation stents, it may require large trials to prove the clinical efficacy of the heparin- coating against noncoated devices. However, even if the "added value" of the heparin-coating will never be clinically proven, it has helped to enhance the penetration of stent therapy in interventional cardiology. Unlike the situation in 1992, very few cardiologists will now disagree with the statement that stents contribute to the state-of-the-art treatment of patients with angina pectoris or acute myocardial infarction. A preliminary comparison of available trials also suggests that the heparin-coated Palmaz-Schatz stent (Cordis Corp., Waterloo, Belgium) is as effective as the noncoated stent plus abciximab treatment.

  16. Optical trapping of coated microspheres

    NARCIS (Netherlands)

    Bormuth, V.; Jannasch, A.; Ander, M.; van Kats, C.M.; van Blaaderen, A.; Howard, J.; Schäffer, E.

    2008-01-01

    In an optical trap, micron-sized dielectric particles are held by a tightly focused laser beam. The optical force on the particle is composed of an attractive gradient force and a destabilizing scattering force. We hypothesized that using anti-reflection-coated microspheres would reduce scattering a

  17. Finite Element Analysis of Ceramic Coatings under Spherical Indentation with Metallic Interlayer: Part Ⅰ Uncracked Coatings

    Institute of Scientific and Technical Information of China (English)

    Minh-Quy LE; Seock-Sam KIM

    2006-01-01

    Spherical indentation of ceramic coatings with metallic interlayer was performed by means of axisymmetric finite element analysis (FEA). Two typical ceramic coatings with relatively high and low elastic modulus deposited on aluminum alloy and carbon steel were considered. Various combinations of indenter radius-coating thickness ratios and interlayer thickness-coating thickness ratios were used in the modeling. The effects of the interlayer, the coating and the substrate on the indentation behavior, such as the radial stress distribution along the coating surface as well as the coating interface, and the plastic deformation zone evolution in the substrate were investigated in connection with the above mentioned ratios. The coating cracking dominant modes were also discussed within the context of the peak tensile stresses on the coating surface and on the coating interface.

  18. Atomically Bonded Transparent Superhydrophobic Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Aytug, Tolga [ORNL

    2015-08-01

    Maintaining clarity and avoiding the accumulation of water and dirt on optically transparent surfaces such as US military vehicle windshields, viewports, periscope optical head windows, and electronic equipment cover glasses are critical to providing a high level of visibility, improved survivability, and much-needed safety for warfighters in the field. Through a combination of physical vapor deposition techniques and the exploitation of metastable phase separation in low-alkali borosilicate, a novel technology was developed for the fabrication of optically transparent, porous nanostructured silica thin film coatings that are strongly bonded to glass platforms. The nanotextured films, initially structurally superhydrophilic, exhibit superior superhydrophobicity, hence antisoiling ability, following a simple but robust modification in surface chemistry. The surfaces yield water droplet contact angles as high as 172°. Moreover, the nanostructured nature of these coatings provides increased light scattering in the UV regime and reduced reflectivity (i.e., enhanced transmission) over a broad range of the visible spectrum. In addition to these functionalities, the coatings exhibit superior mechanical resistance to abrasion and are thermally stable to temperatures approaching 500°C. The overall process technology relies on industry standard equipment and inherently scalable manufacturing processes and demands only nontoxic, naturally abundant, and inexpensive base materials. Such coatings, applied to the optical components of current and future combat equipment and military vehicles will provide a significant strategic advantage for warfighters. The inherent self-cleaning properties of such superhydrophobic coatings will also mitigate biofouling of optical windows exposed to high-humidity conditions and can help decrease repair/replacement costs, reduce maintenance, and increase readiness by limiting equipment downtime.

  19. Nanocrystalline Ni-W coatings on copper

    Energy Technology Data Exchange (ETDEWEB)

    Panagopoulos, C.N., E-mail: chpanag@metal.ntua.gr [Laboratory of Physical Metallurgy, National Technical University of Athens, Zografos, 15780, Athens (Greece); Plainakis, G.D.; Lagaris, D.A. [Laboratory of Physical Metallurgy, National Technical University of Athens, Zografos, 15780, Athens (Greece)

    2011-04-15

    Nanocrystalline Ni-W coatings were produced on copper substrates with the aid of electrodeposition technique. The morphology, chemical composition and structure of the produced coatings were examined with the aid of scanning electron microscopy (SEM), electron dispersive spectroscopy (EDS) and X-ray diffraction (XRD) techniques. The microhardness of alloy Ni-W coatings on copper substrate was also studied. The adhesion between the Ni-W coating, having W content 50 wt%, and the copper substrate, was also studied with a scratch testing apparatus. The scratch tests resulted in the coatings suffering an intensive brittle fracture and minor delamination.

  20. Development of the Fully Aulomated Coating Machine

    OpenAIRE

    伊藤, 信孝; 立岩, 博之; Ito, Nobutaka; Tateiwa, Hiroyuki

    1999-01-01

    Direct sowing by use of coated rice has been gradually accpetcd in recent 20 years. Coating is the necessary key process to promote and irnprove the germination and sprouting percentage for the coated seed when sowed into the soil.In this paper,the development of the automated coating machine and its functional concept were introduced.The purpose of this studyis to automntc thc proccss of coating the chemi-cals uniformly around the rice seed and to improve the working environment under the u...