DFT study of structural, electronic and optical properties of Hg3S2Br2 crystal

We present new DFT study results of electronic and optical properties for Hg3S2Br2. The calculations were carried out using GGA, MBJ, GGA + U, GGA + U + SO, and MBJ + U + SO approaches. The primary objective of this work is to study the optical constants of Hg3S2Br2. The band structure calculation reveals that Hg3S2Br2 is a direct band gap semiconductor with Eg = 2.72 eV. The physical origin and mechanisms that determine the anisotropy of the optical properties of Hg3S2Br2 are established. The results show that the main contribution of the S-p and Br-p states occurs at the top of the valence band while Hg-s and S-p states contribute majorly at the bottom of the conduction band. The monoclinic structure causes considerable anisotropy of optical spectra at 0-1 eV, but it is decrease at higher energies. The obtained data may be applicable in the device creation on the basis of Hg3S2Br2 crystals.

Automated summary

We present new DFT study results of electronic and optical properties for Hg3S2Br2, which is a direct band gap semiconductor with Eg = 2.72 eV. The optical anisotropy of Hg3S2Br2 is determined, and the contribution of different states to the band structure is analyzed. The monoclinic structure causes considerable anisotropy of optical spectra at lower energies but decreases at higher energies. These findings may be utilized in the development of devices based on Hg3S2Br2 crystals.