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A. Azéma J. Botineau F. Gires A. Saïssy 《Applied Physics A: Materials Science & Processing》1979,19(2):145-147
A dielectric slab deposited on a conducting substrate can guide different types of electromagnetic modes. We present the study
of the lowest-order TM mode, which is a distortion of surface polaritons at the air/substrate and layer/substrate junctions. 相似文献
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Currently, triple‐junction solar cells realized from III–V semiconductor compounds hold the solar energy conversion efficiency world record. To improve the efficiency significantly, it is necessary to increase the number of junctions and to involve a sub‐cell with an absorber layer in the band gap range of 1 eV. For the realization of a stacked four‐junction device with optimised band gaps, we have grown InGaAsP/InGaAs tandem cells lattice matched to InP substrates, and investigated properties of the absorber bulk material. Time‐resolved photoluminescence of the low band gap In0.53Ga0.47As absorber embedded between InP barriers was measured. The InGaAs/GaAsSb tunnel diode structure used in the tandem has been processed into a separate device and I –V curves were measured. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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S. Venkatachalam Yoshinori Kanno D. Mangalaraj Sa.K. Narayandass 《Physica B: Condensed Matter》2007,390(1-2):71-78
Zinc Selenide (ZnSe) thin films were deposited onto well cleaned glass substrates using vacuum evaporation technique under a vacuum of 3×10−5 mbar. The prepared ZnSe samples were implanted with mass analyzed 75 keV B+ ions at different doses ranging from 1012 to 1016 ions cm−2. The composition, thickness, microstructures, surface roughness and optical band gap of the as-deposited and boron-implanted films were studied by Rutherford backscattering (RBS), grazing incidence X-ray diffraction, Atomic force microscopy, Raman scattering and transmittance measurements. The RBS analysis indicates that the composition of the as-deposited and boron-implanted films is nearly stoichiometric. The thickness of the as-deposited film is calculated as 230 nm. The structure of the as-deposited and boron-implanted thin films is cubic. It is found that the surface roughness increases on increasing the dose of boron ions. In the optical studies, the optical band gap value decreases with an increase of boron concentration. In the electrical studies, the prepared device gave a very good response in the blue wavelength region. 相似文献
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Sabit Korçak Süleyman Çörekçi Hongbo Yu Semran Sa?lam Ekmel Özbay 《Surface science》2007,601(18):3892-3897
The structural and optical properties of an InxGa1−xN/GaN multi-quantum well (MQW) were investigated by using X-ray diffraction (XRD), atomic force microscopy (AFM), spectroscopic ellipsometry (SE) and photoluminescence (PL). The MQW structure was grown on c-plane (0 0 0 1)-faced sapphire substrates in a low pressure metalorganic chemical vapor deposition (MOCVD) reactor. The room temperature photoluminescence spectrum exhibited a blue emission at 2.84 eV and a much weaker and broader yellow emission band with a maximum at about 2.30 eV. In addition, the optical gaps and the In concentration of the structure were estimated by direct interpretation of the pseudo-dielectric function spectrum. It was found that the crystal quality of the InGaN epilayer is strongly related with the Si doped GaN layer grown at a high temperature of 1090 °C. The experimental results show that the growth MQW on the high-temperature (HT) GaN buffer layer on the GaN nucleation layer (NL) can be designated as a method that provides a high performance InGaN blue light-emitting diode (LED) structure. 相似文献