浮法玻璃表面光学常数分析

本文通过光谱椭偏仪测量浮法玻璃空气面和锡面的偏振信息,利用Cauchy光学模型分析得到浮法玻璃两表面的布鲁斯特角和光学常数,分析结果表明浮法玻璃空气面、锡面、理想玻璃界面的布鲁斯特角分别为56.7°、57°和56.8°,空气面形成疏松的表面层,厚度为2.75nm,折射率小于玻璃本底,锡面形成锡扩散表面层,厚度为81.29nm,折射率大于玻璃本底折射率,并且随厚度呈现出非线性梯度变化,结合透光率数据分析得到玻璃消光系数在10-6量级。由于浮法玻璃空气面和锡面的折射率明显不同,需要在后续玻璃镀膜光学设计时区别对待。     

Selective formation of GaN-based nanorod heterostructures on soda-lime glass substrates by a local heating method

We report on the fabrication of high-quality GaN on soda-lime glass substrates, heretofore precluded by both the intolerance of soda-lime glass to the high temperatures required for III-nitride growth and the lack of an epitaxial relationship with amorphous glass. The difficulties were circumvented by heteroepitaxial coating of GaN on ZnO nanorods via a local microheating method. Metal-organic chemical vapor deposition of ZnO nanorods and GaN layers using the microheater arrays produced high-quality GaN/ZnO coaxial nanorod heterostructures at only the desired regions on the soda-lime glass substrates. High-resolution transmission electron microscopy examination of the coaxial nanorod heterostructures indicated the formation of an abrupt, semicoherent interface. Photoluminescence and cathodoluminescence spectroscopy was also applied to confirm the high optical quality of the coaxial nanorod heterostructures. Mg-doped GaN/ZnO coaxial nanorod heterostructure arrays, whose GaN shell layers were grown with various different magnesocene flow rates, were further investigated by using photoluminescence spectroscopy for the p-type doping characteristics. The suggested method for fabrication of III-nitrides on glass substrates signifies potentials for low-cost and large-size optoelectronic device applications.     

Deposition by magnetron sputtering and characterization of indium tin oxide thin films

In this work the properties of indium tin oxide (ITO) films deposed on glass substrates by magnetron sputtering technique in the temperature range below 200 °C are studied by various methods. The physical properties of ITO thin films have been investigated using optical transmittance, photoluminescence, atomic force microscopy, ellipsometry, Hall-effect and four point probe methods. It is established that properties of ITO layers depend drastically on the temperature and oxygen partial pressure during the deposition process and exhibit some peculiarities of the surface morphology. It is found that the band gap energy of this material varies in the energy range from 4.1 to 4.4 eV and depends on the growth conditions. It is suggested that local deviations from the stoichiometry and defects are the main physical reasons of Burstein-Moss shift of the optical band gap.     

ZrO2-SiO2薄膜对离子交换增强玻璃的光学和力学性能影响

采用溶胶-凝胶法在玻璃表面制备出ZrO₂-SiO₂薄膜, 然后通过离子交换形成镀膜增强玻璃, 研究了薄膜组成对离子交换增强玻璃的力学和光学性能的影响。利用紫外可见分光光度计、激光椭偏仪、纳米压痕、三点抗弯和能谱(EDX)分析了薄膜结构及性能。结果表明: 所有薄膜均连续均匀, 纯ZrO₂薄膜为四方相结构, 含Si薄膜为无定形结构; 薄膜具有较高弹性恢复率(>60%)以及H/E比(>0.1), 有利于强度增强; 随Si含量增加, 可见光透过率增大, 但表面硬度和杨氏模量随之降低; 0.5ZrO₂-0.5SiO₂薄膜综合性能最佳: 表面硬度为18 GPa, 抗弯强度为393 MPa, 厚度~45 nm时可见光透过率大于85%。     

Optical and microstructural properties of p-type SrCu2O2: First principles modeling and experimental studies

In this paper, we report first principles calculations and experimental studies of the optical and microstructural properties of both bulk and thin films of SrCu₂O₂. Polycrystalline SrCu₂O₂ films were grown by a conventional Pulsed Laser Deposition method in a flowing oxygen environment on corning glass 7059 and silicon substrates. Several characterization techniques, including X-ray diffraction (XRD), Fourier Transform IR (FTIR), Raman, spectroscopic ellipsometry, reflectance/transmission spectrophotometry and Atomic Force Microscopy have been used for the investigation of the microstructural and vibrational properties of both bulk and thin films of SrCu₂O₂.XRD shows that bulk SrCu₂O₂ is polycrystalline and assumes the pure tetragonal phase of SrCu₂O₂. The vibrational properties of the tetragonal phase of SrCu₂O₂ have been inferred from Raman and FTIR spectroscopies and for the first time both Raman and IR active modes have been assigned. The bulk polycrystalline SrCu₂O₂ optical band gap determined from spectroscopic ellipsometry was 3.34 ± 0.01 eV. XRD results confirmed that pure non-textured polycrystalline phase SrCu₂O₂ thin films with a smooth surface can be grown by PLD at low temperature (300 °C).     

Thin film passive solar windows produced by reactive evaporation of In-Sn

The semiconductor indium tin oxide (ITO) when present as a thin film has been shown to be transparent to visible radiation while opaque to IR radiation. Sputtering, chemical vapor deposition and other coating methodologies have been used to prepare ITO thin films. Reactive evaporation is an alternative coating technique, which has as its major advantage technical simplicity. Our prepation of ITO thin films (30–90 nm) for passive solar windows included the reactive evaporation of In-Sn alloys (In-5wt.%Sn, In-10wt.%Sn and In-20wt.%Sn) onto commercial soda-lime glass held between 25 and 300 °C. The reactive evaporation atmosphere consisted of oxygen at partial pressures from 1 × 10^-4 to 1 × 10^-3 Torr in residual nitrogen. In selected instances ultrathin palladium nucleating layers were evaporated onto the glass substrates prior to the deposition of the ITO. This was done in order to minimize initial alloy-glass agglomeration effects, thus decreasing the final overall ITO film thickness while increasing the visible transmission properties. The film's visible and IR spectral transmission properties were examined using ratio recording spectrophotometry. The agglomeration, nucleation and growth phenomena of the films were extensively investigated by transmission electron microscopy. The agglomeration was found to be a function of the film thickness, with increasing agglomeration for thinner films. Surface analysis by scanning Auger microscopy (SAM), electron spectroscopy for chemical analysis (ESCA), scanning electron microscopy and energy-dispersive analysis of X-rays was also extensively carried out to determine our particular film properties. SAM indicated that only indium, tin and oxygen were present. No tungsten from the evaporation filament or elements from the glass were found. ESCA indicated that ITO was indeed present on the surface. Such work definitely indicated that ITO can be prepared by reactive physical vapor deposition and that the resultant films have the properties commonly found in sputtered ITO films.     

Optical properties of gold island films—a spectroscopic ellipsometry study

Metal island films of noble metals are obtained by deposition on glass substrates during the first stage of evaporation process when supported metal nanoparticles are formed. These films show unique optical properties, owing to the localized surface plasmon resonance of free electrons in metal nanoparticles. In the present work we study the optical properties of gold metal island films deposited on glass substrates with different mass thicknesses at different substrate temperatures. The optical characterization is performed by spectroscopic ellipsometry at different angles of incidence and transmittance measurements at normal incidence in the same point of the sample. Fitting of the ellipsometric data allows determining the effective optical constants and thickness of the island film. A multiple oscillator approach was used to successfully represent the dispersion of the effective optical constants of the films.     

Spectrographic ellipsometry study of a liquid crystal display substrate consisting of thin films of SiO2, polyimide and indium tin oxide on glass

Variable angle spectrometric ellipsometry at room temperature is used to determine thin film parameters of substrates used in liquid crystal displays. These substrates consist of sequential thin films of polyimide (PI), on indium tin oxide (ITO),on SiO₂ deposited on a glass backing approximately 1.1 mm thick. These films were studied by sequentially examining more complex systems of films (SiO₂, SiO₂-ITO, SiO₂-ITO-PI). The SiO₂ layer appears to be optically uniform and flat. The ITO film is difficult to characterize. When this surface film's lower surface is SiO₂ and upper surface is an air-ITO-interface it is found that including surface roughness and variation of the optical properties with ITO thickness in the model improved the fit; suggesting that both phenomena exist in the ITO films. However, the surface roughness and graded nature of optical properties could be not determinable by ellipsometry when the ITO is coated with a polyimide film. The PI films are ellipsometrically flat and over the wavelength range from 500 to 1400 nm the real refractive index of polyimide films varying in thickness between 25 and 80 nm is well modeled by a two-term Cauchy model with no absorption. The ellipsometric thickness of the ITO layer is the same as the profilometric thickness; however, the ellipsometric thickness of the polyimide layers is roughly 10 nm larger than that obtained from the profilometer. These final observations are consistent with the literature.     

Deposition of gold nanoparticles upon bare and indium tin oxide film coated glass based on annealing process

We presented a simple and efficient strategy for deposition of gold nanoparticles (AuNPs) upon transparent bare and indium tin oxide (ITO) film coated glass substrate using gold colloids as Au sources. The method involved two steps: embedding in polyvinyl alcohol (PVA) film and annealing at high temperature. The AuNPs deposited on solid substrate because of migration and coalescence of gold at high temperature. The optical and structural properties of the AuNPs were characterised by UV-vis absorption spectra and scanning electron microscopy. The results indicate that the surface of AuNPs upon substrate was clean as annealing at 600?°C for 0.5?h. The size of AuNPs deposited on ITO glass increased with annealing time and volume of PVA-AuNPs. Meanwhile, the localised surface plasmon resonance peak of AuNPs deposited on substrate was also gradual red-shift. In addition, the size of AuNPs deposited on ITO substrate was larger than that on bare glass. This work provides a simple, low-cost and large-scale method for fabrication of substrate-based AuNPs, which is benefit for exploiting biosensors, photonic devices and optoelectronic devices.     

Preparation of ITO films using a spray pyrolysis solution containing an acetylacetone chelating agent

Indium tin oxide (ITO) films were deposited on soda-lime glass substrates by the spray pyrolysis method using a spray solution of InCl₃·3H₂O as a precursor, SnCl₄·5H₂O as a dopant and acetylacetone (AcAcH) as a chelating agent. The effect of the addition of AcAcH to the spray solution on the surface morphology of the ITO film was investigated. The surface quality of the film prepared from the spray solution with AcAcH was better than that without AcAcH. The ITO film with the thickness of 230 nm, using the spray solution with AcAcH, exhibited the lowest resistivity of 4.75 × 10^?4 Ω·cm and higher optical transmittance of 85 %, respectively.     

Characterization of nanostructured GaSb: comparison between large-area optical and local direct microscopic techniques

Low energy ion-beam sputtering of GaSb results in self-organized nanostructures with the potential of structuring large surface areas. Characterization of such nanostructures by optical methods is studied and compared to direct (local) microscopic methods. The samples consist of densely packed GaSb cones on bulk GaSb, approximately 30, 50, and 300 nm in height, prepared by sputtering at normal incidence. The optical properties are studied by spectroscopic ellipsometry, in the range 0.6-6.5 eV, and with Mueller matrix ellipsometry in the visible range, 1.46-2.88 eV. The optical measurements are compared to direct topography measurements obtained by scanning electron microscopy, high resolution transmission electron microscopy, and atomic force microscopy. Good agreement is achieved between the two classes of methods when the experimental optical response of the short cones (<55 nm) is inverted with respect to topological surface information, via a graded anisotropic effective medium model. The main topological parameter measured was the average cone height. Optical methods are shown to represent a valuable characterization tool of nanostructured surfaces, in particular when a large coverage area is desirable. Because of the fast and nondestructive properties of optical techniques, they may readily be adapted to in situ configurations.     

玻璃空间电离辐照着色研究

对几种玻璃(K9-HL玻璃、JGS3石英玻璃、K509玻璃以及JGS1石英玻璃)在电离辐照(质子、电子)作用下的光学稳定性进行了系统研究, 并以此为基础, 通过空间电离辐照在玻璃作用的模拟计算, 对这几种玻璃在轨(近地点350 km, 远地点425 km, 轨道倾角51.6^o)光学寿命进行了预测. 在该轨道使用10年时, K9-HL玻璃可见光透过率可能出现明显下降, 而JGS3石英玻璃、K509玻璃以及JGS1石英玻璃的可见光透过率保持不变或变化很小. 由于绝大多数空间粒子穿透能力小, 空间电离辐照仅能造成玻璃表层的着色. 因此, 长期在轨航天器舷窗可加一防电离辐照层以减少内层玻璃接受的电离辐照量, 而该层玻璃可采用石英玻璃.     

Ultradense, deep subwavelength nanowire array photovoltaics as engineered optical thin films

A photovoltaic device comprised of an array of 20 nm wide, 32 nm pitch array of silicon nanowires is modeled as an optical material. The nanowire array (NWA) has characteristic device features that are deep in the subwavelength regime for light, which permits a number of simplifying approximations. Using photocurrent measurements as a probe of the absorptance, we show that the NWA optical properties can be accurately modeled with rigorous coupled-wave analysis. The densely structured NWAs behave as homogeneous birefringent materials into the ultraviolet with effective optical properties that are accurately modeled using the dielectric functions of bulk Si and SiO2, coupled with a physical model for the NWA derived from ellipsometry and transmission electron microscopy.     

靶功率对溅射沉积CIGS薄膜的结构与光学性能的影响

采用单靶磁控溅射方法分别在玻璃和镀有Mo背电极的Soda-lime玻璃衬底上沉积Cu(In0.7Ga0.3)Se2(CIGS)薄膜。研究了靶功率变化对CIGS薄膜的晶体结构、表面形貌和光学性能的影响。采用XRD表征薄膜的组织结构,SEM和EDS观察和分析薄膜的表面形貌和成分,紫外-可见光分光光度计测试薄膜的透过率光谱。结果表明,在不同功率下制备的CIGS薄膜均具有(112)面择优取向。当溅射功率为300W时,CIGS薄膜的表面形貌最平整,结晶最均匀,n(Cu):n(In):n(Ga):n(Se)=30.00:15.01:3.97:51.03组分符合高效吸收层的要求。溅射沉积的CIGS薄膜对可见光的平均透过率低于2%,光学带隙约为1.4eV。     

Determination of the refractive index of single crystal bulk samples and micro-structures

We present comparative studies for the exact determination of the refractive index of single crystals using spectroscopic ellipsometry and photonic-mode-structure investigations by means of spatially resolved photoluminescence spectroscopy, especially in the near band-gap spectral range. By applying such complementary methods we can overcome the uncertainties in the determination of the bulk refractive index introduced by surface properties. The physical effects used are the electromagnetic field reflection used by spectroscopic ellipsometry at large scale planar single crystals and the whispering-gallery-mode formation by total internal reflection in confined micro-structures. We demonstrate the applicability of such studies using the example of uniaxial ZnO bulk samples and micro-wires. By assuming a surface near region with electronic properties different from the bulk material, the method presented here gives the refractive index dispersion for both types of samples in an energy range from 1 to 3.4 eV.     

Optical bonding using silica nanoparticle sol-gel chemistry

A simple method is described to bond optical components using silica nanoparticle sol-gel chemistry. The silica nanoparticles polymerize into highly branched networks that link the surfaces together. The nanoparticle mediated bonding has several advantages to currently used optical joining technologies. The bonding is a room-temperature process and does not require any clean room facilities. The bonded interface has a high mechanical strength and low scattering. The bonding is resistant to organic solvents on silylation with hydrophobic surface groups. This method achieves 100% successful bonding rates between soda-lime glass slides. The bond-setting time can be tailored to allow time for precision optical alignment.     

Formation and properties of cadmium sulfide buffer layer for CIGS solar cells grown using hot plate bath deposition

In the present study, cadmium sulfide (CdS) thin films were deposited on different substrates [soda glass, fluoride doped tin oxide, and tin doped indium oxide (ITO) coated glass] by a hot plate method. To control the thickness and the reproducibility of the sample production, the thin films were coated at different temperatures and deposition times. The CdS thin films were heated at 400 °C in air and forming gas (FG) atmosphere to investigate the effect of the annealing temperatures. The thickness of the samples, measured by ellipsometry, could be controlled by the deposition time and temperature of the hot plate. The phase formation and structural properties of CdS thin films were studied by X-ray diffraction and scanning electron microscopy, whereas the optical properties were obtained by UV–vis spectroscopy. A hexagonal crystal structure was observed for CdS thin films and the crystallinity improved upon annealing. The structural and optical properties of CdS thin films were also enhanced by annealing at 400 °C in FG atmosphere (95 % N₂, 5 % H₂). The optical band gap was changed from 2.25 to 2.40 eV at different annealing temperatures and gas atmospheres. A higher electrical conductivity, for the sample annealed at FG, was noticed. The samples deposited on ITO and annealed in FG atmosphere showed the best structural and electrical properties compared to the other samples. CdS thin films can be widely used for application as a buffer layer for copper–indium–gallium–selenide solar cells.     

Preparation and mechanical properties of a new Zr–Al–Ti–Cu–Ni–Be bulk metallic glass

In this paper, a new Zr₃₇Al₁₀Ti_12.5Cu_11.25Ni₉Be_20.25 bulk metallic glass is reported. The present alloy was prepared by water quenching in a silica tube of φ10×85 mm. The amorphicity of the quenched bulk samples was examined using X-ray diffraction analysis and optical microscopy. The thermal stability was evaluated by differential scanning calorimetry (DSC) at a heating rate of 10 K/min. The characteristic data of the bulk metallic glass are presented, including glass transition temperature (T_g) and crystallization temperature (T_x). Results show that the present alloy exhibits large glass forming ability. For comparison with the well-known Zr–Ti–Cu–Ni–Be metallic glass, it was found that aluminum has a little effect on the vitrification of the present alloy but influences physical properties. Specifically, Al enhances the Young's modulus by 21.4% and Vickers hardness by 20% and reduces density by 7.2%.     

Study of optical properties and light induced effects on Inq3 thin film used in organic light emitting devices

In this report, the optical properties of tris-(8-hydroxyquinoline) metal complex Inq₃; used as light-emitting layer in electroluminescent (EL) devices are shown. The material has been synthesized and the thin films have been deposited by thermal evaporation on quartz and silicon substrates. The optical constants (n and k) of Inq₃ thin films have been determined using spectroscopic ellipsometry. Light induced effects on optical properties of films have been studied using ellipsometry, photoluminescence and UV–visible transmission measurements. Enhanced photoluminescence intensity with shift in peak position as well as modification in optical constants on light exposure in vacuum indicates phase transformation in Inq₃ films.     

Characterization of vapor-deposited l-leucine nanofilm

X-ray reflective measurements (XRR), atomic force microscopy and single wavelength ellipsometry were used to investigate the optical properties of thin l-leucine films deposited onto silicon substrates. The ellipsometry data (Ψ,Δ) were fitted with a four-layer-model, and the optical refractive index of the l-leucine film measured with ellipsometry was determined to be 1.37. With the conventional effective medium approximation theory and the ellipsometry results, the density of the l-leucine nanofilm was determined to be 70% (0.81 g/cm³) of crystalline l-leucine. This value was in good agreement with the density of 69% (0.80 g/cm³) obtained with XRR measurement. The ellipsometry measurements also enabled us to estimate the surface roughness or absorption layer of the film. This procedure of combined XRR and ellipsometry measurements could be a powerful tool for the determination of the (otherwise hard-to-determine) refractive index in thin organic material films with a rough surface layer.