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

The ab-initio method has been applied to explore the chalcopyrite compounds HgGa2X4 (X = S, Se) structural, optoelectronics, and 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 bandgap values of both compounds, we used Trans along with Bhala 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, which are accurately comparable to experimental values. It also observed that the strong optical absorption is below 3.0 eV, which made both compounds favorable for solar cell device applications. In last, we make a detailed investigation of thermoelectric characteristics in terms of electric and thermal conductivity, power factor, and figure of merit (ZT) with the help of the BoltzTrap code. To check the material's thermal stability, we accomplished the thermal parameters against temperatures.