Temperature-dependent optical properties of epitaxial CdO thin films determined by spectroscopic ellipsometry and Raman scattering

被引:17
作者
Choi, S. G. [1 ]
Gedvilas, L. M. [1 ]
Hwang, S. Y. [2 ]
Kim, T. J. [2 ]
Kim, Y. D. [2 ]
Zuniga-Perez, J. [3 ]
Munoz Sanjose, V. [3 ]
机构
[1] Natl Renewable Energy Lab, Golden, CO 80401 USA
[2] Kyung Hee Univ, Dept Phys, Seoul 130701, South Korea
[3] Univ Valencia, Dept Fis Aplicada & Electromagnetismo, E-46100 Burjassot, Spain
关键词
R-PLANE SAPPHIRE; DIELECTRIC FUNCTION; GAP; SEMICONDUCTORS;
D O I
10.1063/1.4803876
中图分类号
O59 [应用物理学];
学科分类号
摘要
We report temperature-dependent optical properties of epitaxial CdO thin films grown by metal-organic vapor phase epitaxy on sapphire substrates. Dielectric function epsilon = epsilon(1) + i epsilon(2) spectra for CdO were extracted from the multilayer modeling of ellipsometric data, using a set of Tauc-Lorentz oscillators from 0.74 to 6.43 eV in the temperature range between 24 and 650 K. Temperature dependence of the energy for the major optical structures in the e spectra was analyzed by using Varshni's approximation. Raman scattering (RS) spectroscopy was used to characterize the vibrational properties of CdO from 77 to 500 K. Several RS peaks were observed in the wavenumber range from 100 to 1000 cm(-1). Peak positions, accurately determined by a series of Gaussian-Lorentzian mixed line profiles, exhibit a weak linear dependence on temperature. (C) 2013 AIP Publishing LLC.
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页数:5
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