DFT Simulation of Eco-friendly Halide Double Perovskites A2AuInCl6 (A = K and Rb) for Optoelectronic and Thermoelectric Devices

This study has performed first-principles simulations to examine the properties of perovskite compounds formed by substituting potassium (K) or rubidium (Rb) for the element A in the structure A(2)AuInCl(6) (A = K and Rb). The research ensures the thermal and structural stability of these materials through an analysis of their formation energy and tolerance factor. These features demonstrate that the compounds possess stability under typical settings. The study assesses the elastic properties of the compounds using the IRelast tool within the WIEN2k software, revealing that both materials exhibit advantageous elastic stability, ductility, and anisotropy. The compounds are categorized as direct band gap semiconductors, with bandgap values of 0.88 eV for K2AuInCl6 and 0.86 eV for Rb2AuInCl6. This analysis makes them suitable for optoelectronic applications. Optical analysis demonstrates that these materials efficiently absorb sunlight across the visible to ultraviolet spectrum, hence enhancing their suitability for optoelectronic applications. The study further investigates their thermoelectric characteristics, demonstrating ZT values of 0.70 for K2AuInCl6 and 0.69 for Rb2AuInCl6, indicating its use in thermoelectric devices. These compounds exhibit advantageous characteristics for use in optoelectronic and thermoelectric technologies, due to their stability, semiconductor properties, efficient light absorption, and thermoelectric effectiveness.