Ab initio calculations of structural, electronic, and optical properties of Cu2HgSnSe4

The electronic structure of Cu2HgSnSe4 in stannite structure is studied by the first-principles calculations. This material is a direct band-gap compound. In addition, the dielectric function, absorption coefficient, reflectivity, and energy-loss function are studied using the density functional theory within the generalized gradient approximation. We discuss the optical transitions between the valence bands and the conduction bands in the spectra of the imaginary part of the dielectric function at length. High and wide optical absorption spectrum is obtained. There are several prominent peaks for Cu2HgSnSe4 in the reflectivity spectra. And a rapid decrease of reflectance corresponds to the prominent peak in the energy-loss spectrum.

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► We simulate the electronic and optical properties of Cu2HgSnSe4 in theory.
► This material is the direct band-gap compound.
► We discuss the optical transitions between the VBs and CBs in ε2(ω) spectrum in detail.
► High and wide optical absorption spectrum is obtained.