Computational Modelling of the structural, phase stability, electronic, optical, and elastic behaviour of layered perovskites Rb2AgAsM6 (M = Cl and F) halide materials for optoelectronics Devices.

The computational modeling of Rb2AgAsM6 (M = Cl and F) double perovskite halides is thoroughly examined in this work using the DFT model. Rb2AgAsM6 compounds ensured their prospective utility by meeting stability requirements for cubic structures. Formation (-817.951, -925.63) eV/atoms, cohesive (817.951, 925.63) eV/atoms energy, and tolerance factor (0.89, 0.78) of the compounds Rb2AgAsM6 (M = Cl and F) are measured for structural and thermal stability. Using the GGA-PBE approx., We found that the indirect electronic band gaps of Rb2AgAsM6 (M = Cl and F) fall between 1.34 eV and 2.29 eV. These values show that because of the strong spin-orbit coupling from heavy cations, the indirect band gaps of compounds fall inside the visible region. The Rb2AgAsM6 (M = Cl and F) compounds have mechanical Born stability, according to the calculated bulk modulus (41.254, 19.851) GPa. We found that when photon energy (eV) is applied to the Rb2AgAsM6 (M = Cl and F) compounds, the complex dielectric function promotes the greatest electron transition and absorption efficiency. These results highlight the potential of double perovskites made of Rb2AgAsM6 compounds for energy applications. According to DFT analysis, our study demonstrates the stability and advantageous characteristics of Rb2AgAsM6 (M = Cl and F) double perovskites. These findings underscore the potential of Rb2AgAsM6 (M = Cl and F) perovskites as environmentally friendly materials for advanced solar cells, optoelectronic devices, and next-generation technologies.