Study of pressure-induced halide double perovskite, Cs2LiGaBr6, for photovoltaic applications

Abstract

The production of lead-free halide double perovskites with visible spectrum bandgaps is an important advancement in the design of sustainable perovskite solar cells. In this study, DFT (Density Functional Theory) is used to examine the structural, optical, electrical, and mechanical characteristics of the lead-free Cs2LiGaBr6 double halide perovskites under hydrostatic pressure ranging from 2 GPa to 80 GPa. A decrease in the lattice constant is the result of increasing pressure. Direct band gaps are present in all Cs2LiGaBr6 compounds which progressively become wider under pressure. Changes in quantum confinement effects that are caused by compressive strain are largely responsible for the band gap variations under pressure. An examination of the optical characteristics and density of states indicates increased absorption in the visible band for the UV spectrum under pressure. The mechanical stability research highlights the compound's viability for thin-film fabrication by confirming its ductile character under pressure. This study highlights the potential of Cs2LiGaBr6 in a variety of settings and expands the knowledge of sustainable substitutes for perovskite optoelectronic applications.