Programme

P.17 -- Poster, VCTP-44

Date: Tuesday, 30 July 2019

Time: 08:30 - 10:00

DFT calculation of electronic and optical properties of quaternary sulfide Cu2HgSnS4: a prospective photovoltaic semiconductor

Tuan V. Vu (1,2), A.A. Lavrentyev (3), B.V. Gabrelian (4), Khang D. Pham (1,2), Duy D. Vo (1,2), Phuc Toan Dang (1,2), O.V. Parasyuk (5), O.Y. Khyzhun (6)

(1) Division of Computational Physics, Institute for Computational Science, Ton Duc Thang University, Ho Chi Minh City, Vietnam; (2) Faculty of Electrical & Electronics Engineering, Ton Duc Thang University, Ho Chi Minh City, Vietnam; (3)Department of Electrical Engineering and Electronics, Don State Technical University, 1 Gagarin Square, 344010 Rostov-on-Don, Russian Federation; (4) Department of Computational Technique and Automated System Software, Don State Technical University, 1 Gagarin Square, 344010 Rostov-on-Don, Russian Federation; (5) Department of Inorganic and Physical Chemistry, Lesya Ukrainka Eastern European National University, 13 Voli Avenue, UA-43025 Lutsk, Ukraine; (6) Frantsevych Institute for Problems of Materials Science, National Academy of Sciences of Ukraine, 3 Krzhyzhanivsky Street, UA-03142 Kyiv, Ukraine

The data of Cu2HgSnS4 electronic band-structure was obtained by applying DFT calculation. Different exchange-correlation (XC) approaches were employed to achieve the best total density of states (TDOS) curve in comparison with X-ray photoelectron spectroscopy (XPS). The VB XPS spectrum and TDOS were in good agreement with experimental data when applying MBJ+U+SO technique, in which modified Becke-Johnson (mBJ) was used to describe the XC interaction, the spin-orbit (SO) effect was taken into account, and the strongly correlated electrons of d state was described by the adjusting parameter U. The electronic band structure and optical constant of Cu2HgSnS4 were calculated by MBJ+U+SO technique. The Hg 5d and Cu 3d states are the principal contributors to the bottom and the central part of the Cu2HgSnS4 valence band, respectively, while its upper part is dominated by S 3p states. Regarding the occupancy of the conduction band, the present APW+lo calculations manifest that its bottom is dominated by the unoccupied Sn 5s states.

Presenter: Vu Van Tuan