Interfacial effect on the optoelectronic and piezoelectric properties of Ge-Sn terminated Halide Perovskite heterostructure from first-principles study

Abstract

Since the very early stages of research on sustainable technologies, green energy conversion has always been a prime focus. With the discoveries of countless functional materials in recent years, significant progress has been made to meet the global energy demand for sustainable development. Among them, halide perovskites have emerged as one of the most promising and reliable materials. In this work, we have investigated the lead-free halide perovskites, vis CsGeCl3 and RbSnBr3, within a framework of density functional theory (DFT) to explore their potential applicability in harvesting clean and renewable energy. This study gives a comprehensive analysis of the bulk, surface (001), and Ge-Sn-terminated interfaces within GGA and mGGA functionals. Interestingly, the inherent asymmetric arrangements of the systems exhibit remarkable optoelectronic and piezoelectric properties. The piezoelectric performance of each surface cut has been validated through the electromechanical coupling calculation.