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排序方式: 共有900条查询结果,搜索用时 828 毫秒
51.
Prakash Koirala Jian Li Heayoung P. Yoon Puruswottam Aryal Sylvain Marsillac Angus A. Rockett Nikolas J. Podraza Robert W. Collins 《Progress in Photovoltaics: Research and Applications》2016,24(8):1055-1067
Polycrystalline CdS/CdTe thin‐film solar cells in the superstrate configuration have been studied by spectroscopic ellipsometry (SE) using glass side illumination. In this measurement method, the first reflection from the ambient/glass interface is rejected, whereas the second reflection from the glass/film‐stack interface is collected; higher order reflections are also rejected. The SE analysis incorporates parameterized dielectric functions ε for solar cell component materials obtained by in situ and variable‐angle SE. In the SE analysis of the complete cells, a step‐wise procedure ranks the fitting parameters, including thicknesses and those defining the spectra in ε, according to their ability to reduce the root‐mean‐square deviation between the simulated and measured SE spectra. The best fit thicknesses from this analysis are found to be consistent with electron microscopy. Based on the SE results, the solar cell quantum efficiency (QE) can be simulated without any free parameters, and comparisons with measured QE enable optical model refinements as well as identification of optical and electronic losses. These capabilities have wide applications in photovoltaic module mapping and in‐line monitoring. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
52.
Douglas R. Robello 《应用聚合物科学杂志》2013,127(1):96-103
Soluble, colorless polymers containing pendant diamondoid moieties (adamantane and diamantane) were synthesized and characterized. The materials exhibited an unusual combination of moderately high refractive index with low optical dispersion. These properties may make the polymers valuable as specialty optical plastics. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
53.
In this work, we present the optical constants of bismuth telluride (Bi2Te3), and antimony telluride (Sb2Te3) determined using spectroscopic ellipsometry (SE). The spectral range of the optical constants is from 404 nm to 740 nm.
Bi2Te3 and Sb2Te3 films with different thicknesses were grown by metalorganic chemical vapor deposition (MOCVD). Multiple sample analysis (MSA)
technique was employed in order to eliminate the parameter correlation in the SE data analysis caused by the presence of the
overalyer on top of Bi2Te3 and Sb2Te3 films. Optical constants and thicknesses for both Bi2Te3 and Sb2Te3 overlayers were also determined. Independent Bi2Te3 and Sb2Te3 samples were used to check the results obtained. In addition, SE analysis was performed on two Sb2Te3 samples after being etched in diluted NH4OH solution in order to characterize the overlayer and confirm the reliability of the results. 相似文献
54.
K. PrabakarM. Sridharan Sa.K. Narayandass D. MangalarajVishnu Gopal 《Thin solid films》2003,424(1):66-69
The optical response of vacuum-evaporated Cd1−xZnxTe thin films in the 1.5-5.6 eV photon energy range at room temperature has been studied by spectroscopic ellipsometry. The films of Cd1−xZnxTe (x=0.04) were deposited at room temperature onto well-cleaned glass substrates of film thickness 450 nm. The measured dielectric-function spectra reveal distinct structures at energies of the E1, E1+Δ1 and E2 critical points corresponding to the interband transitions. Dielectric related optical constants such as complex refractive index, the absorption coefficients and the normal incidence reflectivity, are presented. Results are in satisfactory agreement with the calculations over the entire range of the photon energies. 相似文献
55.
含碱掺铒磷酸盐玻璃光谱性质的研究 总被引:3,自引:1,他引:2
以72P2O5-8Al2O3-20R2O(R=Li,Na、K)和(77-x)P2O5-8Al2O3-(15 x)Na2O(x=0,5,10,15,20)掺铒磷酸盐玻璃系统为研究对象,测量和计算了掺铒磷酸盐玻璃的各种光谱参数,探讨了不同碱金属氧化物及其含量对掺铒磷酸盐玻璃光谱性质的影响。结果表明,积分吸收截面∑abs、峰值发射截面σemi、J-O强度参量Ωt以及自发辐射几率AR有较强的成分依赖性,并且主要决定于Er^3 离子周围结构和Er-O键共价性的变化;减小Er-O键的共价性可得到较高的∑abs、σemi以及AR。 相似文献
56.
Hg1-xCdxTe is an important material for infrared (IR) detection applications where the bandgap of the alloy varies from semimetal
to 1.4 eV. The large variation in bandgap energy with HgCdTe composition causes difficulty in controlling detector-cutoff
wavelength, particularly for the long-wavelength IR and very-long-wavelength infrared (VLWIR, greater than 12 μm) spectral
bands. Our ability to control the HgCdTe composition and compositional profile during growth by molecular beam epitaxy (MBE)
is improved significantly by using automated feedback control from spectroscopic ellipsometry (SE) measurements, where the
standard deviation in the error in composition has improved by a factor of 5, from σ=0.0081 to σ=0.0016. To improve our ability
to predict cutoff wavelength from IR transmission measurements, we have used a model of the absorption in HgCdTe to revise
our past empirical cutoff relationship to include the effect of compositional grading. We have achieved a mean detector-cutoff
wavelength of 14.1 μm and standard deviation of σ=0.25 μm for a series of 19 processed layers with a target cutoff of 14 μm.
The excellent control in VLWIR detector cutoff we have observed is attributed to automated compositional control and an improved
cutoff-prediction model. 相似文献
57.
Leonard I. Kamlet Fred L. Terry Jr. George N. Maracas 《Journal of Electronic Materials》1997,26(12):1409-1416
In this work, we discuss a temperature-dependent model for the complex dielectric function for GaAs valid for the temperature
range 31°C ≤ T ≤ 634°C. We describe our model, which is an extension of the critical point parabolic band method. This is
a phenomenological method which is based on the physical processes occurring in the semiconductor, and has been previously
demonstrated for composition-dependent models of the dielectric function for lattice-matched materials systems. We demonstrate
the quality of the model in fitting optical data for individual temperatures, and compare our results to other established
models. The data used for each fitting ranges from 1.25 to 4.5 eV. Using results obtained from the individual fits, we generate
a temperature-dependent model that is valid for the range of temperatures given above. Also, we show how this model can be
used to accurately determine the temperature (±2.3°C) of a material whose dielectric response has been obtained but was not
included when generating the model. 相似文献
58.
新型光敏剂竹红菌甲素的强激光效应及电子激发态特性 总被引:2,自引:0,他引:2
有机功能分子在开发新型光电子材料和光动力疗法(PDT)光敏剂方面是一个重要的研究热点;竹红菌甲素(HA)分子属于激发态质子转移(ESIPT)型分子,具有丰富的激发态特性,且反应速度快,在新型激光染料和新型光电器件方面有一定的应用前景。观察了竹红菌甲素分子的激射现象,其发射激光的范围在620~800 nm;并利用激射效应的特点为强激光条件下的质子转移提供了进一步的依据。利用瞬态光栅技术研究了竹红菌甲素的电子激发态特性,把其瞬态光栅的超快过程归结为竹红菌甲素质子转移形成的过渡态TS*的衰减,并得出过渡态TS*瞬态光栅的寿命为10.5 ps。 相似文献
59.
Ji-Ping Xu Rong-Jun Zhang Zhi-Hui Chen Zi-Yi Wang Fan Zhang Xiang Yu An-Quan Jiang Yu-Xiang Zheng Song-You Wang Liang-Yao Chen 《Nanoscale research letters》2014,9(1):188
The BiFeO3 (BFO) thin film was deposited by pulsed-laser deposition on SrRuO3 (SRO)-buffered (111) SrTiO3 (STO) substrate. X-ray diffraction pattern reveals a well-grown epitaxial BFO thin film. Atomic force microscopy study indicates that the BFO film is rather dense with a smooth surface. The ellipsometric spectra of the STO substrate, the SRO buffer layer, and the BFO thin film were measured, respectively, in the photon energy range 1.55 to 5.40 eV. Following the dielectric functions of STO and SRO, the ones of BFO described by the Lorentz model are received by fitting the spectra data to a five-medium optical model consisting of a semi-infinite STO substrate/SRO layer/BFO film/surface roughness/air ambient structure. The thickness and the optical constants of the BFO film are obtained. Then a direct bandgap is calculated at 2.68 eV, which is believed to be influenced by near-bandgap transitions. Compared to BFO films on other substrates, the dependence of the bandgap for the BFO thin film on in-plane compressive strain from epitaxial structure is received. Moreover, the bandgap and the transition revealed by the Lorentz model also provide a ground for the assessment of the bandgap for BFO single crystals. 相似文献
60.
Total internal reflection ellipsometry (TIRE) technique was used to investigate the optical response of different hybrid multilayer systems. It was shown that the optical response was significantly changed by gold nanoparticles, which have been introduced for modification of functional properties of hybrid system. Nevertheless, the dispersion of optical parameters for gold nanoparticles was quite close in various hybrid systems in the case of adequate models used for interpretation of TIRE data. 相似文献