Modulation of electronic and piezoelectric properties of lead-free halide perovskites LiSnX$_3$ (X = Cl, Br, and I) under applied pressure

TL;DR

This study investigates how applying pressure and substituting elements affect the structural, electronic, and piezoelectric properties of lead-free LiSnX3 perovskites, highlighting their potential for energy harvesting applications.

Contribution

It provides a comprehensive theoretical analysis of pressure and elemental effects on LiSnX3 perovskites, revealing their promising piezoelectric properties for green energy solutions.

Findings

LiSnX3 exhibits semi-conducting behavior.

High piezoelectric response up to 20.7 Cm2 observed.

Structural stability confirmed at room temperature.

Abstract

Pb-based perovskites are considered to be the most efficient materials for energy harvest. However, real-time application is limited because of their toxicity. As a result, lead-free perovskites that offer similar advantages are potential alternatives. Here, we have chosen LiSnX$_3$ (X = Cl, Br, and I) for further calculation and explore its possibilities for harvesting clean and green energy. Our objective is to examine strategies for optimizing the parameters that control the energy-harvesting capabilities, particularly the interplay between structural variations and electrical properties. The density functional theory (DFT) has been employed for the theoretical simulation. Within the DFT framework, we have studied the effect of applied pressure (0 to 20 GPa) and elemental substitution on their physical properties. We hereby report the variation of lattice parameters, elastic constants, band gaps, and piezoelectric constants. MD simulation with time steps of up to 5 ps was performed to verify structural stability at room temperature. We report the semi-conducting characteristic of LiSnX$_3$ and the high piezoelectric response up to 20.7 Cm2. The presence of high piezoelectric coefficients suggests that manipulation of the structure of LiSnX$_3$ may provide an alternative way to harvest energy through electromechanical processes.