Computational investigations of optoelectronic properties of K2ScAuX6 (X = Cl, Br) double perovskites for energy harvesting devices

•Halide based double perovskites K2ScAuX6 (X = Br, I) have been theoretically investigated using WEIN2k software.•Structural parameters were optimized using Perdew–Burke–Ernzerhof generized gradient approximation (PBEsol-GGA)•Investgation of mechanical response of these materials revealed their ductile nature.•Indirect band gap nature with bang gap values of 2.20 eV and 1.90 eV were estimated using mBJ potential.•Electronic transport properties in a wide range of temperature has been evaluated.