Ag-based halide perovskites AgEX3 (E = Ge, Sn; X = Cl, Br, I): DFT-driven exploration of structural, optoelectronic, and thermal properties for photovoltaic applications

A new class of halide compounds, AgEX 3 (E = Ge, Sn; X = Cl, Br, I), exhibiting a cubic perovskite structure, was investigated using the APFD/LanL08 hybrid functional within the DFT framework. This study comprehensively analyzed the potential of silver (Ag)-based halide perovskite, specifically their structural, optoelectronic, and thermal properties. The AgEX 3 perovskites are stable, which was validated through their formation energy and a tolerance factor. The observed energy gap ranges from 0.86 eV to 1.20 eV, which falls within the optimal range defined by the Shockley-Queisser limit, making these materials highly suitable for photovoltaic applications. Conceptual-DFT descriptors were also analyzed to evaluate the chemical reactivity and behavior of the studied perovskite materials. The refractive index and dielectric constant values of AgEX 3 suggested their strong light-matter interaction and efficient charge screening, which are beneficial for enhancing photonic absorption applications. The computed thermodynamic properties, including energy storage capacity, entropy, thermal energy, and thermodynamic potential, confirm the thermal constancy of these studied compounds. The results indicate that substitutions at the E-site (Ge, Sn) cations and X-site (Cl, Br, I) anions significantly impact the properties of AgEX 3 materials. These findings strongly indicate that AgEX 3 perovskite materials exhibit favorable properties for photovoltaic applications and also hold potential for use in other optical devices, such as photodetectors, LEDs, and radiation sensors.