Band gap shifting of halide perovskite KSrCl3 from ultra-violet to visible region under pressure for photovoltaic applications

Abstract

This research delves into the influence of hydrostatic pressure on the structural, electronic, and optical characteristics of the cubic halide perovskite KSrCl₃. The reduction in interatomic distance caused by pressure has a considerable effect on the unit cell volume and lattice constant of this perovskite. As pressure increases, the electronic band gap closes, transferring from the ultraviolet to the visible spectrum. This phenomenon increases the efficiency of optoelectronic devices by simplifying the transition of electrons from the valence band to the conduction band. In addition, the material becomes more appropriate for use in a variety of optoelectronic applications when the band gap changes from indirect to direct at pressures of about 50 GPa. A comprehensive optical analysis suggests that KSrCl₃ holds potential applications in surgical tools, integrated circuits, QLED, OLED, solar cells, waveguides, and materials designed for solar heat reduction. The tolerance factor “t" confirms the stability of the KSrCl3 phase across the applied pressure range, and the formation energy values with negative values show the attained thermodynamic stability.