Hydrostatic Pressure-Driven Insights into Structural, Electronic, Optical, and Mechanical Properties of A3PCl3 (A = Sr, Ba) Cubic Perovskites for Advanced Solar Cell Applications

This study explores lead-free cubic perovskites Sr3PCl3 and Ba3PCl3 as sustainable alternatives to lead halide perovskites, focusing on their structural, electronic, optical, and mechanical properties under hydrostatic pressure (0-25 GPa) via DFT and Thermo-PW tools. Both materials transition from direct bandgap semiconductors (1.649 eV for Sr3PCl3 and 0.991 eV for Ba3PCl3) to metallic states at 25 GPa. Pressure-induced redshifts in absorption spectra, along with enhanced dielectric constant, refractive index, and reflectivity, highlight their optical tunability. Mechanical analysis confirms stability, ductility, and resilience under pressure. Additionally, the optimized DFT values were utilized in the suggested FTO/IGZO/A(3)PCl(3)/Cu2O/Ni structures to simulate solar cell performance with SCAPS-1D. Using Sr3PCl3/Ba3PCl3 absorber, the devices attained a peak PCE of 26.66/27.3%, a J(SC) of 22.79/51.05 mA/cm(2), an FF of 89.81/83.08%, and a V-OC of 1.3/0.64 V. This work demonstrates the potential of Sr3PCl3 and Ba3PCl3 perovskites as sustainable, lead-free materials for high-efficiency solar cells and tunable optoelectronic devices, leveraging hydrostatic pressure to optimize performance. Their stability and tunability make them promising for environmentally friendly energy solutions.