Pressure induced semiconductor to metal phase transition in CsSnBr3 perovskite

TL;DR

This study uses first principles calculations to show that applying hydrostatic pressure induces a semiconductor to metal phase transition in CsSnBr3 perovskite, affecting its electronic, optical, and mechanical properties.

Contribution

It provides the first detailed theoretical analysis of pressure effects on CsSnBr3, revealing phase transition and property enhancements relevant for applications.

Findings

Semiconductor to metal phase transition occurs under 16 GPa pressure.

Optical absorption edge shifts to lower energy with pressure.

Mechanical stability and ductility increase with pressure.

Abstract

Phase transitions in metal halide perovskites triggered by external provocations produce significantly different material properties, providing a prodigious opportunity for a comprehensive applications. In the present study, the first principles calculation has been performed with the help of density functional theory (DFT) using CASTEP code to investigate the physical properties of lead-free CsSnBr3 metal halide under various hydrostatic pressures. The pressure effect is determined in the range of 0-16 GPa. Subsequently, a significant change is observed in lattice constant and volume with increasing pressure. The electronic band structure show semiconductor to metal phase transition under elevated pressure. The investigation of optical functions displays that the absorption edge of CsSnBr3 perovskite is shifted remarkably toward the low energy region (red shift) with improved pressure up to 16 GPa. In addition, the absorptivity and dielectric constant also upsurges with the applied hydrostatic pressure. Finally, the mechanical properties reveal that CsSnBr3 perovskite is mechanically stable and highly ductile; the ductility is increased with raising pressure. This type of semiconductor to metal phase transition may inspire a wide range of potential applications.