Pressure induced band gap shifting from ultra-violet to visible region of RbSrCl3 perovskite

Abstract

Metal halide perovskites that do not contain lead are non-toxic and offer a wide range of uses in low-cost photovoltaic and optoelectronic systems. In this report, density functional theory is used to explore the influence of pressure (0-150 GPa) on the structural, electronic and optical characteristics of RbSrCl3 perovskite metal halide. At 0 GPa, RbSrCl3 was found to be an indirect wide-bandgap semiconductor. Under pressure, the electronic band gap transforms to visible range direct band gap which is suitable for optoelectronic devices. Higher absorption for RbSrCl3 was found in the ultraviolet region under the influence of different pressures. As the pressure on the halide perovskite increased, absorption peak is shifted to higher energy range. The optical conductivity, reflectivity and extinction coefficient were significantly changed due to induced pressures. The results suggest that under uniform pressure RbSrCl3 can be used in optoelectronic applications.