Pressure-induced band gap engineering and enhanced optoelectronic properties of non-toxic ZnInF3 perovskite: Insights from density functional theory

Metal halide perovskites (MHPs) are promising candidates for optoelectronic applications, but enhancing their optical performance remains a significant challenge. In this study, we investigate the structural, electronic, dynamic, and optical properties of orthorhombic ZnInF₃ under hydrostatic pressure using first-principles calculations. Our results demonstrate that increasing pressure leads to a substantial reduction in interatomic distances and unit cell dimensions while preserving thermodynamic stability. Notably, the electronic band gap decreases significantly from 2.676 eV to 1.410 eV at 200 GPa, thereby enhancing electron excitation and charge transport. Concurrently, pressure improves key optical properties, including the static dielectric constant, reflectivity, refractive index, absorption, and conductivity across the spectrum. These enhancements collectively indicate that ZnInF₃ is a highly tunable and stable material with strong potential for next-generation, non-toxic solar cell applications. Our findings contribute to the design of advanced optoelectronic materials and support future innovations in sustainable energy technologies.