Opto-electronic, and thermoelectric properties of chalcopyrite compounds HgGa₂X₄(X = S, Se) for solar cell applications

Abstract

The ab-initio method has been applied to explore the chalcopyrite compounds HgGa2X4 (X= S, Se) structural, opto-electronics, and also thermoelectric characteristics. We attained the optimized parameters of lattice constant by employing Perdew-Burke-Ernzerhof generalized gradient approximation (PBEsol-GGA) and computed the values are approximately equal to experimental values. To calculate accurate band-gap values of both compounds, we used Trans along with Blaha reformed Becke and Johnson (TB-mBJ). Remarkably, both HgGa2X4 (X= S, Se) compounds yield a direct bandgap nature having calculated values 2.80 eV and 2.30 eV respectively, those are accurately comparable to experimental values. It also observed that the strong optical-absorption is below 3.0eV, which made both compounds favorable for solar cell device applications. In last, we make a detail investigation of thermoelectric characteristics in terms of electric and thermal conductivity, power factor and figure of merit (ZT) with the help of BoltzTrap code. To check the thermal stability of material, we accomplished the thermal parameters against temperatures.