Theoretical studies of the structural, electronic, and optical properties of Cu2HgGeS4

Authors

  • Dan Li,

    1. Department of Materials Science and Engineering, Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055, P. R. China
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  • Furi Ling,

    1. School of Optoelectronic Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
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  • Xinghong Zhang,

    Corresponding author
    1. Department of Materials Science and Engineering, Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055, P. R. China
    2. Center for Composite Materials, Harbin Institute of Technology, Harbin 150001, P. R. China
    • Phone: +86-755-26033759, Fax: +86-755-26033759
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  • Zhenye Zhu

    1. Department of Materials Science and Engineering, Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055, P. R. China
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Abstract

We present a first-principles investigation of the electronic structure for Cu2HgGeS4 in stannite structure using the screened-exchange density functional method. This crystal is a direct-band-gap semiconductor, and the calculated band gap is 1.27 eV. The dielectric function, absorption coefficient, reflectivity, and energy-loss function in the two independent polarizations are also studied using the density functional theory (DFT) within the screened-exchange local density approximation (sX-LDA). We discuss the high-frequency dielectric constant and optical transitions between the valence bands (VBs) and the conduction bands (CBs) in the spectra of the imaginary part of the dielectric function at length. We also find a very high absorption coefficient and a wide absorption spectrum for this material. The prominent structures in the spectra of reflectivity and energy-loss function are discussed in detail. The anisotropy is reflected in all the optical spectra.

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