Investigating structural, phonons, optoelectronics, and thermodynamic properties of lead-free double perovskites of A-site cation ordering in LiXTl2Cl6 (X= Sc and Y) compounds for green energy applications

Abstract

This study explores the structural, phonons, optoelectronic, and thermodynamic properties of LiXTl2Cl6 (X= Sc and Y) compounds. These double perovskite materials are particularly interesting due to their potential for green energy applications. We employ state-of-the-art computational simulation techniques to investigate the structural properties of these compounds, focusing on the cation ordering in the A-site of the perovskite structure. Through density functional theory (DFT) calculations, we determine the equilibrium crystal structure and lattice parameters, shedding light on the stability of these materials. Furthermore, we analyze the phonon spectra to assess the materials' vibrational properties, including the presence of any phonon modes that may impact thermal stability and thermal transport. Optoelectronic properties, such as band gaps and optical absorption spectra, are also explored to evaluate the suitability of these materials for photovoltaic and light-emitting applications. We investigate their electronic structure and consider the potential for efficient charge carrier generation and transport. The thermodynamic properties, such as heat capacity, entropy, and enthalpy, are calculated to provide insight into the compounds' thermal behavior under various environmental conditions, which is crucial for green energy applications, including thermal energy conversion. This comprehensive investigation into the LiXTl2Cl6 (X= Sc and Y) compounds aims to contribute to developing lead-free double perovskite materials with tailored properties for a range of green energy applications, paving the way for more sustainable and environmentally friendly energy solutions.