Enhanced optical absorption by Ag nanoparticles in a thin film Si solar cell

Thin film solar cells have the potential to significantly reduce the cost of photovoltaics. Light trapping is crucial to such a thin film silicon solar cell because of a low absorption coefficient due to its indirect band gap. In this paper, we investigate the suitability of surface plasmon resonance Ag nanoparticles for enhancing optical absorption in the thin film solar cell. For evaluating the transmittance capability of Ag nanoparticles and the conventional antireflection film, an enhanced transmittance factor is introduced. We find that under the solar spectrum AM1.5, the transmittance of Ag nanoparticles with radius over 160 nm is equivalent to that of conventional textured antireflection film, and its effect is better than that of the planar antireflection film. The influence of the surrounding medium is also discussed.     

格兰-汤普森棱镜胶合层的膜效应分析

将格兰-汤普森棱镜两半块之间的光学胶合层作为一层薄膜,利用薄膜光学理论,分析了胶合层对棱镜透射比的影响。通过研究胶合层的厚度以及光学胶折射率对入射光在胶合界面上反射率的影响,得出了s偏振光经过格兰-汤普森棱镜后的透射比。结果表明：胶合层的厚度以及光学胶折射率对棱镜的透射比均有影响,且厚度对棱镜透射比的影响呈现周期性变化;而光学胶折射率则对透射比的振荡幅度产生影响。以长度孔径比为3的格兰-汤普森棱镜为例,光学胶折射率为1．510时,棱镜的透射比在92．5％～90．8％之间振荡;光学胶的折射率在接近e光主折射率1．475～1．495之间取值时,棱镜透射比的振荡幅度较小。这一结果有利于对格兰-汤普森棱镜性能的优化。     

ITO材料在减反射膜设计中的应用

改变ITO材料通常作为透明导电膜单独使用的状况,将其作为减反射膜系中的一层,能够在很大程度上增加ITO透明导电膜在可见光部分的透过率.通过使用将ITO材料置于膜系的内层和最外层两类不同的设计思想,可以使ITO透明导电膜达到相当优良的应用效果.使用低压反应离子镀方法制备了设计的两类减反射膜系,实验证明,膜层在可见光部分的透过率显著提高,剩余反射率明显下降,并得到了平均透过率为95.83%,最高透过率达到97.26%,方块电阻为13.2～24.6Ω/□的试验结果.     

ZnO-SnO_2透明导电薄膜的制备及性能研究

采用二步成胶工艺制备ZnO-SnO_2透明导电薄膜,应用X射线衍射、原子力显微镜、紫外-可见分光光度计、薄膜分析仪及四探针仪等对薄膜的结构、表面微观形貌、透过率和导电性能进行表征.结果表明,锌锡摩尔比为9/12,退火温度为500 ℃时,薄膜的透过率达90%,电阻率为3.15×10~(-3) Ω·cm.与其它工艺相比,二步成胶工艺所制备出的ZnO-SnO_2透明导电薄膜性能优异.     

Characteraction of Ag-doped ZnO thin film synthesized by sol–gel method and its using in thin film solar cells

Pure 2% and 4% Ag-doped ZnO thin films have been synthesized on glass substrates by sol–gel method. The structure, morphology and optical properties of the samples have been studied by X-ray diffractometer (XRD), scanning probe microscope, UV–vis spectrophotometer, respectively. The XRD result shows that the pure ZnO has a wurtzite hexagonal structure, no phase segregation is observed. The surface morphology of pure ZnO thin film shows that the grains are growing preferentially along the c-axis orientation perpendicular to the substrates. The transmittance spectra reveal that all samples have high transmittance above 90% in visible region. With Ag doping content increase, a red shift is observed. The performance of Ag-doped ZnO films using in thin film solar cells are simulated. The results show that 4% Ag-doped ZnO thin film can greatly improve the absorption of the cells. Compare to pure ZnO, solar cell's energy conversion efficiency improvement of 2.47% is obtained with 4% Ag doped ZnO thin film.     

ZnO-SnO2透明导电薄膜的制备及性能研究

采用二步成胶工艺制备ZnO-SnO₂透明导电薄膜,应用X射线衍射、原子力显微镜、紫外-可见分光光度计、薄膜分析仪及四探针仪等对薄膜的结构、表面微观形貌、透过率和导电性能进行表征.结果表明,锌锡摩尔比为9/12,退火温度为500 ℃时,薄膜的透过率达90%,电阻率为3.15×10-3 Ω·cm.与其它工艺相比,二步成胶工艺所制备出的ZnO-SnO₂透明导电薄膜性能优异.     

Optical and hydrophilic properties of Cr doped TiO2-SiO2 nanostructure thin film

Cr doped TiO₂-SiO₂ nanostructure thin film on glass substrates was prepared by a sol-gel dip coating process. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to characterize the structural and chemical properties of the films. A UV-vis spectrophotometer was used to measure the transmittance spectra of the thin film. The hydrophilicity of the thin film during irradiation and storage in a dark place was measured by a contact angle analyzer. The results indicated that Cr doping has a significant effect on the transmittance and super-hydrophilicity of TiO₂-SiO₂ thin film.     

Influence of various thickness metallic interlayers on opto-electric and mechanical properties of AZO thin films on PET substrates

Various thickness metallic interlayers to improve the opto-electric and mechanical properties of aluminum-doped zinc oxide (AZO) thin films deposited on flexible polyethylene terephtalate (PET) substrates are studied. The effects of the interlayers on the resistance and transmittance of the AZO thin films are discussed. The result shows that the metallic interlayers effectively improve the electric resistance but reduce the optical transmittance of the AZO thin films. These phenomena become more obvious as the interlayer thickness increases. However, the AZO with an aluminum interlayer still behaves an acceptable transmittance. Moreover, mechanical tests indicate that the aluminum interlayer increases the hardness and modulus, and reduce the residual stress of the AZO thin films. In contrast, the silver and copper interlayers decrease the AZO's mechanical properties. Comparing to those without any interlayer, the results show that the best interlayer is the 6 nm thick aluminum film.     

CdSe量子点滤光片尺寸、温度依赖的光学特性

为了缩小光谱仪体积使之适用于军事卫星等领域,本文将胶体量子点作为滤光材料,研究了CdSe胶体量子点滤光片的光学特性.本文采用热注入法合成出了高质量的CdSe胶体量子点,经过对苯二胺消光处理制备成CdSe胶体量子点滤光片.利用透射电子显微镜(TEM)进行样品形貌结构的表征及粒径尺寸的测量,并分别在不同温度下进行了紫外.可...     

激光辐照VO2薄膜温度场分布及透射特性研究

为了探究VO₂薄膜受激光辐照的温度场分布,以及1 064 nm激光直接辐照100 s内至相变的激光功率密度阈值,并比较近红外和中红外波段透过率调制特性差异。首先基于COMSOL建立了薄膜受激光辐照的模型并进行了温度场仿真,然后分别测试了薄膜正反面被不同功率密度的1 064 nm激光辐照100 s内激光透过率随时间响应特性。实验中的VO₂薄膜利用分子束外延法在Al₂O₃基底上制备得到。仿真结果表明,激光功率密度为25 W·mm^-2时,50 nm厚薄膜在被辐照1 ms时间内即达到相变温度。经激光辐照实验发现:50 nm厚的VO₂薄膜正反面受1 064 nm激光直接辐照100 s内至相变的功率密度阈值分别为4.1 W·mm^-2和5.39 W·mm^-2。30 nm厚VO₂薄膜对1 064 nmn激光的透过率调制深度约为13%,对3 459 nm激光透过率调制深度约62%,说明VO₂薄膜对近红外透过率调制特性不明显。     

Opals with a thin-film metallic defect-hybrid colloidal plasmonic photonic crystals

Hybrid photonic crystals consisting of a thin-film opal and a thin profiled gold film situated on the surface or inside the opal have been prepared. The optical transmittance spectra of hybrid crystals have been studied. It has been found that the spectra exhibit minima due to diffraction resonances in the photonic crystal and bands of enhanced transmission due to transfer of radiation through the metal film surface by plasmon polaritons. It has been shown that the transmittance spectra of hybrid crystals with a metal film on the surface are subjected to a stronger modification than the hybrids having a metal film inside the crystal.     

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.     

Investigation of transmittance property of Palladium thin films fabricated by pulsed laser deposition with polarization using single layer model

In this paper the structure, morphology and optical properties of Pd thin films deposited on glass substrate by pulse laser deposition technique at two different substrate temperatures have been investigated. The fabricated films were characterized by various methods such as XRD, AFM, and UV-vis-NIR spectroscopy. The influence of surface roughness and angle of incidence with p polarization was investigated experimentally by optical property of palladium (Pd) thin films of two different thicknesses and rms roughness from transmission measurement in the visible spectral range. It has been shown that the experimental transmittance spectra agree well with their theoretical values for absorbing Pd thin film. The transmittance of thin film increases with increase in incident angle for the same sample.     

光学薄膜的等离子体离子镀的研究

根据薄膜沉积过程等离子体对光学薄膜膜蒸气分子或原子的作用，建立低压等离子体离子镀设备，并对常规光学薄膜、如硫化物、氧化物薄膜以及多层膜器件进行了系统的研究，对所制备薄膜样品的透射光谱、吸收、散射以及膜层的聚集密度等进行了全面的测试分析。实验研究表明，低压等离子体离子镀可大大提高常规光学薄膜的光机性能。     

Physical nature of anomalous optical transmission of thin absorptive corrugated films

The enhancement of p-polarized light transmittance through periodically relief thin absorptive film on dielectric or semiconductor substrate was considered theoretically. The calculation of transmittance/reflectance was performed in the framework of modified differential formalism method. Numerical results obtained for noble metals (Au, Ag and Cu) under arbitrary relief correlation between two sides of film allow ascertaining physical nature of surface electromagnetic fields responsible for the enhancement transmittance effect. These are Fano, Zenneck-Sommerfeld and Brewster modes on the interfaces with absorbing medium. For anticorrelated reliefs of opposite film surfaces the bound of their modes was found especially effective. The article is published in the original.     

Fabrication of an optically transparent super-hydrophobic surface via embedding nano-silica

Super-hydrophobic thin films were prepared on glass by combining embedded nano-silica, subsequent fluoroalkylsilane coating. The hydrophobic capability of film depended on the concentration of nano-silica suspension. And the super-hydrophobic thin film shows the high transmittance in visible light wavelength.     

MBE法制备VO2薄膜及其中红外调制深度测量

为了给VO₂薄膜在定向红外对抗系统防护方面的应用提供理论依据,我们用透过率调制深度表征VO₂薄膜在中红外波段的相变特性。本实验利用分子束外延法（MBE）制备VO₂外延单晶薄膜,经XRD、AFM表征,发现其具有（020）择优取向、纯度较高,薄膜表面平整、均匀且致密。经VU-Vis-IR测量发现其近红外透过率相变特性显著,但在紫外和可见光范围内透过率相变特性较不明显。然后我们对制备时间为30 min、40 min的两组薄膜分别进行25~70℃的升温和降温实验,观察其对波长为3 459 nm、脉宽50 ns、重频50 kHz、功率密度0.14 W/cm²的中红外激光的透过率变化,并比较两组薄膜的温滞曲线特性。实验发现它们对中红外透过率的调制深度均可达60%以上,前者比后者对中红外的调制深度高出约4%。这说明利用分子束外延法制备的VO₂单晶薄膜具有良好的中红外调制特性,且调制深度和膜厚有关。进一步表明了利用VO₂薄膜实现中红外激光防护具有一定的可行性。     

Convenient and inexpensive determination of optical constants and film thickness of blended organic thin film

This work presents the study of optical constants and film thickness of blended organic thin films, emphasizing on the modeling procedure with modified genetic algorithm aided by absorption or transmittance spectra of both pure materials and the blends. Taking the blending of copper phthalocyanine(Cu Pc) and fullerene(C60) as an example, a simple, convenient and low-cost method for the determination of the optical constants and film thickness of blended organic thin films was demonstrated. New scheme for optical modeling of blended organic thin film was proposed by introducing peak energies of Cody-Lorentz oscillators of the pure materials, which were determined by fitting the film absorption of pure materials. These oscillators of pure materials could be recognized in the transmittance spectrum of their blends, and were further used as the initial searching ranges in the simulation of blended films. As a result, the constraint bounds of the unknown parameters were significantly reduced and modeling efficiency as well as fitting accuracy was improved. For instance, the fitting of the transmittance curves of blended films with different blending ratios reached reliable results in comparison with extinction coefficients obtained from experiment.     

在半导体-金属相变温度附近氧化钒薄膜光学性质的异常变动

在可见光—近红外波段的不同波长下,测量了半导体-金属相变过程中氧化钒薄膜样品的反射率和透射率.在薄膜相变过程中,不同波段的反射率曲线和透射率曲线表现出不同的变化趋势.利用非相干光在薄膜中的多级反射-透射模型,计算了相变过程中不同波长下氧化钒薄膜的折射率n和消光系数k随温度的变化.结果表明,在相变温度附近氧化钒薄膜光学性质的异常变动,其原因既有薄膜的折射率和消光系数随波长的变化趋势不同,也有在吸收性薄膜中存在探测光多次反射和透射的累加效应.     

自支撑Zr膜制备及软X射线透过性能研究

软X射线波段滤光膜材料大都为自支撑金属薄膜,实验室环境下自支撑薄膜长期与空气接触表面易氧化,空气中的杂质原子进入自支撑薄膜内部,致使自支撑膜光学性能大幅下降.5 nm至20 nm软X射线波段Zr具有较低的质量吸收系数和较小的密度,在该波段Zr滤光膜透过率较高.采用脱模剂法制备自支撑Zr膜,在洁净的浮法玻璃上蒸镀一层Na...