The Determination of the Mechanical, Optoelectronic, Structural and Transport Attributes of Double Perovskite A₂InGaBr₆ (A=K, Rb, Cs) Halides for Renewable Energies: A DFT Study

Abstract

Safer and more environmentally friendly alternatives to lead‐based perovskites include lead‐free halide perovskites, which retain good optoelectronic capabilities while reducing environmental toxicity. They also align better with ecological and regulatory standards for green technologies. In this manuscript, we have presented the first principles analysis of the physical traits of A2InGaBr6 (A=K, Rb, Cs). The exchange‐correlation effects are treated with mBJ potential. The structural characteristic of A2InGaBr6 (A=K, Rb, Cs) was assessed through the volume optimization curves, formation energies and tolerance factor. The elastic properties of the studied halides are analyzed through elastic constants. The electronic band structures revealed indirect bandgaps for K2InGaBr6, Rb2InGaBr6, and Cs2InGaBr6. The optical properties indicate promising potential in the fabrication of optoelectronic devices for A2InGaBr6 (A=K, Rb, Cs). The transport properties for the studied halides are computed using the BoltzTraP code, which reveals that these halides are promising candidates for thermoelectricity.