Surface Plasmon Interference Lithography Assisted by a Fabry-Perot Cavity Composed of Subwavelength Metal Grating and Thin Metal Film

A surface plasmon interference lithography assisted by a Fabry-Perot （F-P） cavity composed of subwavelength metal gratings and a thin metal fihn is proposed to fabricate high-quality nanopatterns. The calculated results indicate that uniform straight interference fringes with high contrast and high electric-field intensity are formed in the resist under the F-P cavity. The analyses of spatial frequency spectra illuminate the physical mechanism of the formation for the interference fringes. The influence of the F-P cavity spacing is discussed in detail. Moreover, the error analyses reveal that all parameters except the metal grating period in this scheme can bear large tolerances for the device fabrication.

Competing failure mechanisms of thin metal films on polymer substrates under tension

The ductility of thin metal films on polymer substrates reported in recent experiments has a huge disparity,ranging from less than 1 % up to more than 50 %.To reveal the underpinning origins for such a large variation,this paper reports a systematic computational study of two competing failure mechanisms:metal film necking and grain boundary cracking.The quantitative results suggest that strong grain boundaries and metal/polymer interfacial adhesion are keys to achieve high ductility of polymer-supported metal films.

The effect of fiber orientation on fracture response of metallic fiber-reinforced adhesive thin films

Incorporation of metallic fibers into the adhesive layer can significantly improve the mechanical behavior of the adhesive joint. This paper aims to assess the fracture behavior of an epoxy adhesive reinforced by longitudinal and lateral metallic fibers. Double cantilever beam(DCB) specimens were used to obtain the fracture energy of both non-reinforced and reinforced adhesives under mode I loading condition. In addition to the fiber orientation, the distance between the metal fibers was considered as the second key parameter in the experiments. It was concluded that although incorporation of metallic fibers in the adhesive layer improves the fracture behavior of neat adhesive, however, higher improvements were observed for the adhesive reinforced with longitudinal fibers. Furthermore, reducing the fiber distances resulted in higher values of fracture energy.

NUMERICAL SIMULATION FOR MEASURING YIELD STRENGTH OF THIN METAL FILM BY NANOINDENTATION METHOD

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Design of periodic metal-insulator-metal waveguide back structures for the enhancement of light absorption in thin-film solar cells

To increase the absorption in a thin layer of absorbing material （amorphous silicon, a-Si）, a light trapping design is presented. The designed structure incorporates periodic metal-insulator-metal waveguides to enhance the optical path length of light within the solar cells. The new design can result in broadband optical absorption enhancement not only for transverse magnetic （TM）-polarized light, but also for transverse electric （TE）-polarized light. No plasmonic modes can be excited in TE-polarization, but because of the coupling into the a-Si planar waveguide guiding modes and the diffraction of light by the bottom periodic structures into higher diffraction orders, the total absorption in the active region is also increased. The results from rigorous coupled wave analysis show that the overall optical absorption in the active layer can be greatly enhanced by up to 40%. The designed structures presented in this paper can be integrated with back contact technology to potentially produce high-efficiency thin-film solar cell devices.

Influence of Zr(50)Cu(50) thin film metallic glass as buffer layer on the structural and optoelectrical properties of AZO films

Aluminum-doped ZnO(AZO) thin films with thin film metallic glass of Zr(50)Cu(50) as buffer are prepared on glass substrates by the pulsed laser deposition. The influence of buffer thickness and substrate temperature on structural, optical, and electrical properties of AZO thin film are investigated. Increasing the thickness of buffer layer and substrate temperature can both promote the transformation of AZO from amorphous to crystalline structure, while they show(100)and(002) unique preferential orientations, respectively. After inserting Zr(50)Cu(50) layer between the glass substrate and AZO film, the sheet resistance and visible transmittance decrease, but the infrared transmittance increases. With substrate temperature increasing from 25℃ to 520℃, the sheet resistance of AZO(100 nm)/Zr(50)Cu(50)(4 nm) film first increases and then decreases, and the infrared transmittance is improved. The AZO(100 nm)/Zr(50)Cu(50)(4 nm) film deposited at a substrate temperature of 360℃ exhibits a low sheet resistance of 26.7 ?/, high transmittance of 82.1% in the visible light region, 81.6% in near-infrared region, and low surface roughness of 0.85 nm, which are useful properties for their potential applications in tandem solar cell and infrared technology.

Synthesis of Metal/Poly(diphenylsilylenemethylene) Nanocomposite Thin Films by Pulsed Laser Ablation

A new technique to synthesize poly（diphenylsilylenemethylene） （PDPhSM） matrix nanocomposite thin films containing metal nanoparticles such as Ni, AI, Zn, and W produced by pulsed laser ablation has been developed. First, 1,1,3,3-tetra- phenyl-1,3-disilacyclobutane （TPDC） films were deposited on 4 cm2 silicon substrates cut from c-Si wafers by conventional vacuum evaporation under a pressure of 4.0×10^-3 Pa; then metal nanoparticles were deposited onto the TPDC films by pulsed laser ablation; finally the TPDC films with metal nanoparticles were heated in an electric furnace in an air atmosphere at 553 K for 10 rain to induce ring-opening polymerization of TPDC. The results indicate that it is easy to synthesize metal/ PDPhSM nanocomposite thin films by pulsed laser ablation. The morphologies and size of metal nanoparticles are closely related to the kinds of metal. Also, the polymerization efficiency depends on the kinds of metal nanoparticles deposited on the TPDC monomer films by pulsed laser ablation. In addition, The laser ablated metal nanoparticles penetrate into the TPDC monomer films during pulsed laser ablation while the DC sputtered metal nanoparticles just lay on the surface of TPDC films.

Metal Organic Chemical Vapour Deposited Thin Films of Cobalt Oxide Prepared via Cobalt Acetylacetonate

The single solid source precursor, cobalt （Ⅱ） acetylacetonate was prepared and characterized by infrared spectroscopy. Thin films of cobalt oxide were deposited on soda lime glass substrates through the pyrolysis （metal organic chemical vapour deposition （MOCVD）） of single solid source precursor, cobalt acetylacetonate, Co[C5H7O2]2 at a temperature of 420℃. The compositional characterization carried out by rutherford backscattering spectroscopy and X-ray diffraction （XRD）, showed that the films have a stoichiometry of Co2O3 and an average thickness of 227±0.2 nm. A direct energy gap of 2,15±0.01 eV was calculated by the data obtained by optical absorption spectroscopy. The morphology of the films obtained by scanning electron microscopy, showed that the grains were continuous and uniformly distributed at various magnifications, while the average grain size was less than i micron for the deposited thin films of cobalt oxide.

Synthesis and Characterization of Metal Organic Chemical Vapour Deposited Chromium Doped Zinc Oxide Thin Film for Gas Sensing Applications

Chromium (Cr) doped Zinc oxide ZnO thin films were deposited onto glass substrates by Metal Organic Chemical Vapour Deposition (MOCVD) technique with varying dopant concentration at a temperature of 420°C. The effect of the chromium concentration on morphological, structural, optical, electrical and gas sensing properties of the films were investigated. The scanning electron microscopy results revealed that the Cr concentration has great influence on the crystallinity, surface smoothness and grain size. X-ray diffraction (XRD) studies shows that films were polycrystalline in nature and grown as a hexagonal wurtzite structure. A direct optical band energy gap of 3.32 to 3.10 eV was obtained from the optical measurements. The transmission was found to decrease with increasing Cr doping concentration. Rutherford Backscattering Spectroscopy (RBS) analysis also demonstrates that Cr ions are substitutionally incorporated into ZnO. I-V characteristic of the film shows a resistivity ranges from 1.134 × 10-2 · cm to 1.24 × 10-2 · cm at room temperature. The gas sensing response of the films were enhanced with incorporation of Cr as a dopant with optimum operating temperature around 200°C.

Various Metal Sandwich Layer Oriented Efficiency Enhancement Superiority on CuInGaSe2 Thin Film Solar Cells

The good quality CuInGaSe2 (CIGS) thin film solar cells were fabricated on molybdenum metal coated soda lime glass substrate. Three-stage co-evaporation method was utilized for the fabrication of high quality p-type CIGS thin film absorber layer. Further, n-type CdS layer, high resistive intrinsic ZnO layer and transparent conducting AlZnO layers were fabricated by CBD method and vacuum sputtering methods. We made three various top metal sandwich grid patterns, i.e. Al, Al/Cu and Cu/Al which were utilized to investigate the metal sandwich layer oriented efficiency enhancement superiority on CuInGaSe2 thin film solar cells. The investigated specific CIGS solar cell device efficiency with respect to various top metal grid sandwich patterns is presented and discussed.

Metal Uptake by Plants from Soil Contaminated by Thin-Film Solar Panel Material

Various metals, including zinc (Zn), nickel (Ni), aluminum (Al), chromium (Cr), gallium (Ga), lead (Pb), copper (Cu) and indium (In), may be released and cause contamination when scrapped end-of-life (EoL) Cu(InGa)Se2 thin-film solar panel (CIGS TFSP) is buried in the soil. In this study, we grew Brassica parachinensis L. H. Bariley (VegBrassica) in three different types of soils, namely, a commercial soil, a Mollisol, and an Oxisol, which had been contaminated by CIGS TFSP to various extents. The concentrations of contaminants in these soils were positively correlated with both the amount of CIGS TFSP added and the burial period. Plants grew well in commercial soil and Mollisol, but those in Oxisol showed prominent signs of chlorosis and died after 30 days. The bioaccumulation factor (BF) and concentration of Zn in VegBrassica grown in commercial soil with 10% of CIGS TFSP added were 3.61 and 296 mg/kg, respectively, while the BF and concentration of In of VegBrassica grown in Mollisol were 3.80 and 13.72 mg/kg, respectively. The results showed that soils were contaminated by metals released from CIGS TFSP, and different adsorption patterns were observed for VegBrassica?depending on which types of metals associated with the soil properties.

Effect of fabrication parameters on the microstructure,in-plane anisotropy and magnetostriction of Fe-Ga thin films

The microstructure,in-plane anisotropy,and magnetic properties of Fe-Ga thin films were investigated by X-ray diffraction analysis,vibrating sample magnetometer,and capacitive cantilever method.The in-plane induced anisotropy is well formed by the applied magnetic field during sputtering,and the anisotropy field Hk decreases with the sputtering power increasing.The coercivity of Fe-Ga thin films decreases with increasing power when the sputtering power is less than 60 W and increases when the power is larger than 60 W.The magnetostriction of the thin films reaches 66 × 10-6 at the sputtering power of 60 W.Excellent Fe-Ga films,which exhibit good field sensitivity,low coercivity and high magnetostriction,have been fabricated at the power of 60 W,and they can be used as the materials of magnetostrictive transducers.

Fractal Characteristics and Microstructure Evolution of Magnetron Sputtering Cu Thin Films

How to describe surface morphology characteristic and microstructure evolution are the hottest researches of current thin film researches. But in traditional characterization of surface morphology, the roughness parameters are scale related. And the microstructure evolution of thin film during post-treatment is usually not considered in detail, To give a better understanding of the roughness of thin films topography, fractal method is carried out. In addition, microstrueture evolution of thin films is analyzed based on the crystallography and energy theory. Cu thin films are deposited on Si （100） substrates by magnetron sputtering, and then annealed at different temperatures. Surface topography is characterized by atomic force microscope （AFM）. Triangular prism surface area （TPSA） algorithm is used to calculate the fractal dimension of the AFM images. Apparent scale effect exists between the surface morphology roughness and film thickness. Relationship between the fractal dimension and roughness is analyzed by linear regression method and linear relationship exists between fractal dimension and surface roughness root mean square （RMS）. Fractal dimension can be characterized as a scale independence parameter to represent the complex degree and roughness level of surface. With the increase of annealing temperature, surface roughness and fractal dimension decrease. But when the annealing temperature exceeds the recrystallization temperature, due to the agglomeration and coalescence of Cu grain, surface roughness and fractal dimension increase. Scale effect and changing regularity of grain growth and shape evolution for different film thickness under different annealing temperatures are analyzed. Based on minimum total free energy, regularity of grain growth and changing is proposed. The proposed research has some theory significance and applicative value of Cu interconnect process and development of MEMS.

Rapid communication Preparation of TiO_2 nanometer thin films with high photocatalytic activity by reverse micellar method

Two kinds of TiO_2 nanometer thin films were prepared on stainless steel bythe reverse micellar and sol-gel methods, respectively. The calcined TiO_ 2 thin films werecharacterized by X-ray diffraction (XRD), atomic force microscopy (AFM), BET surface area and X-rayphotoelectron spectroscopy (XPS). Photocatalytic activity was evaluated by photocatalyticdecoloration of methyl orange aqueous solution. The results showed that the TiO_2 thin filmsprepared by reverse micellar method (designated as RM-TiO_2 films) showed higher photocatalyticactivity than those by sol-gel method (designated as SG-TiO_2 films). This is attributed to the factthat the former is composed of smaller monodispersed spherical particles with a size of about 15 nmand possesses higher surface areas.

Effect of crystallization temperature on microstructure and ferroelectric property of Bi_(3.25)Eu_(0.75)Ti_3O_(12) thin films prepared by MOD method

Europium-substituted bismuth titanate (Bi3.25Eu0.75Ti3O12) thin films were deposited on the Pt/Ti/SiO2/Si(111) substrates by metal-organic decomposition (MOD) method using a repeated coating/drying cycle. Effect of crystallization temperature on microstructure of Bi3.25Eu0.75Ti3O12(BET) thin films was investigated by X-ray diffractometry(XRD), scanning electron microscopy (SEM) and Raman spectroscopy, and ferroelectric property was studied by Precision Workstation Ferroelectric Tester. The crystallinity of BET thin films is improved and the average grain size increases with the crystallization temperature from 600 to 750 ℃. Under 9 V applied voltage, the remnant polarization (2Pr) of BET thin films annealed at 700 ℃ is 50.7 μm/cm2, which is higher than that of the films annealed at 600, 650 and 750℃.

TiO_2 thin film photocatalyst

It is well known that the photocatalytic activity of TiO_2 thin filmsstrongly depends on the preparing methods and post-treatment conditions, since they have a decisiveinfluence on the chemical and physical properties of TiO_2 thin films. Therefore, it is necessary toelucidate the influence of the preparation process and post-treatment conditions on thephoto-catalytic activity and surface microstructures of the films. This review deals with thepreparation of TiO_2 thin film photo-catalysts by wet-chemical methods (such as sol-gel,-reversemicellar and liquid phase deposition) and the comparison of various preparation methods as well astheir advantage and disadvantage. Furthermore, it is discussed that the advancement ofphotocatalytic activity, super-hydrophilicity and bactericidal activity of TiO_2 thin filmphotocatalyst in recent years.

Characterization of Thin Films by Low Incidence X-Ray Diffraction

Glancing Angle X-ray Diffraction (GAXRD) is introduced as a direct, non-destructive, surface-sensitive technique for analysis of thin films. The method was applied to polycrystalline thin films (namely, titanium oxide, zinc selenide, cadmium selenide and combinations thereof) obtained by electrochemical growth, in order to determine the composition of ultra-thin surface layers, to estimate film thickness, and perform depth profiling of multilayered heterostructures. The experimental data are treated on the basis of a simple absorption-diffraction model involving the glancing angle of X-ray incidence.

MOCVD of Molybdenum Sulphide Thin Film Via Single Solid Source Precursor Bis-(Morpholinodithioato-s,s’)-Mo

A single solid source precursor bis-(morpholinodithioato-s,s’)-Mo was prepared and molybdenum sulphide thin film was deposited on sodalime glass using Metal Organic Chemical Vapour Deposition (MOCVD) technique at deposition temperature of 420?C. The film was characterized using Rutherford Backscattering Spectroscopy (RBS), Ultraviolet-Visible Spectroscopy, Four point probe technique, Scanning Electron Mi-croscopy (SEM), X-ray Diffractometry (XRD) and Atomic Force Microscopy (AFM). A direct optical band gap of 1.77 eV was obtained from the analysis of the absorption spectrum. The sheet resistance was found to be of the order of 10P–5P ΩP–1P?cmP–1P. SEM micrographs of the films showed the layered structure of the film with an estimated grain size that is less than 2 μm while XRD indicates parallel orientation of the basal plane to the substrate surface.

Preparation of CuInSe_2 thin films by paste coating

Precursor pastes were obtained by milling Cu-In alloys and Se powders. CulnSe2 thin films were successfully prepared by precursor layers, which were coated using these pastes, and were annealed in a H2 atmosphere. The pastes were tested by laser particle diameter analyzer, simultaneous thermogravimetric and differential thermal analysis instruments （TG-DTA）, and X-ray diffractometry （XRD）. Selenized films were characterized by XRD, scanning electron microscopy （SEM）, and energy dispersive spectroscopy （EDS）. The results indicate that chalcopyrite CuInSe2 is formed at 180℃ and the crystallinity of this phase is improved as the temperature rises. All the CuInSe2 thin films, which were annealed at various temperatures, exhibit the preferred orientation along the （112） plane. The compression of precursor layers before selenization step is one of the most essential factors for the preparation of perfect CuInSe2 thin films.