Systemically study of optoelectronic and transport properties of chalcopyrite HgAl₂X₄ (X= S, Se) compounds for solar cell device applications

This article investigated the structure, optoelectronic characteristics, and transport properties of the Hg-based chalcopyrite HgAl2X4 (X = S, Se) using DFT. To calculate the optimized lattice constant, we applied Perdew-Burke-Ernzerhof s generalized- gradient-approximation (PBEsol-GGA) and found calculated lattice constant of both chalcopyrites is reasonable compared to experimental values. In addition, modified Becke and Johnson (mBJ) potential were used to investigate the optoelectronic properties. Studied HgAl2S4 and HgAl2S4 chalcopyrite compounds have a direct bandgap of 3.20 eV and an indirect bandgap of 2.60 eV, respectively. Projectile and total density of states were computed to check the maximum contribution of chalcopyrite HgAl2X4 (X = S, Se). HgAl2S4 and HgAl2S4 chalcopyrite have a substantial optical absorption near 3.5 eV and 3.9 eV making them interesting for hetero-junction solar cell. Furthermore, based on measured results of large thermal properties, we discovered that the structures are thermally and mechanically robust in a cubic structure. Finally, the BoltzTrap code is used to study the figure of merit (ZT), power factor, Seebeck coefficient, and electrical and thermal conductivity of transport characteristics. (C) 2022 The Authors. Published by Elsevier B.V.