Department of Physics, Faculty of Science,ShahidChamran University,of Ahvaz,Ahvaz,Iran
Abstract
In this paper, the optical properties of HgTe compounds such as dielectric function ε (ω), Refractive coefficients, and extinction index using different approximations in three Zincblend, hexagonal and orthorhombic phases have been studied.The calculations have been performed by pseudopotential method in the framework density functional theory with GGA and LDA approximation by Quantum-Espresso package. The results obtained from the imaginary part of the dielectric function show the correspondence between the optical gap and the band gap.Also, the results of the optical parameters for the two Zincblend and hexagonal phases of the HgTe compound show that this composition has a refractive index of 3.413 in the Zincblend phase and 3.192 and 3.339 in the hexagonal phase,in direction x and z respectively. The reason for the higher refractive index in the Zincblend, than the hexagonal phase can be attributed to the quasi-metallic properties of this compound.
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