A computational approach to study the halides-based double perovskites Cs2InAuX6 (X=Cl, Br) for low-cost energy technologies

Using the computer-based simulations in the framework of WIEN2K, we have investigated the structure, optoelectronic, and thermoelectric properties of lead-free double perovskite halides Cs2InAuX6 (X = Cl, Br). These materials stabilize in the cubic phase due to lower formations energies. Interestingly, the Cs2InAuCl6 (Eg = 0.7 eV) exhibits a narrow band gap while the Cs2InAuBr6 (Eg = 0 eV) shows metallic behavior. Our calculated optical parameter values unambiguously reveal that the infrared (IR) regions exhibit the greatest light absorption, proving that these halides are suitable for application in transistors-based devices. Concerning the transport qualities, the Seebeck coefficient, electrical conductivity, thermal conductivity, and figure of merit are all investigated. Our findings will benefit future experiments on Cs2InAuX6 (X = Cl, Br) for application in renewable energy devices.