Theoretical prediction of the mechanical, electronic, optical and thermodynamic properties of antiperovskites A3BO (A = K, Rb and B = Au, Br) using DFT scheme: new candidate for optoelectronic devices application

Abstract

Density Functional Theory (DFT) is incorporated in this study to examine the thermodynamic, electronic, mechanical, and optical characteristics of antiperovskite compounds A₃BO (A = K, Rb and B = Au, Br). The purpose of the study is to demonstrate a comprehensive understanding of these materials and their potential applications across various fields emphasizing their stability and energetic profiles. The electronic properties, including band structures, and density of states are also analyzed to understand the electrical behavior of these materials, which enables predicting their conductive and semiconductor nature. The band gaps of K₃AuO, K₃BrO, Rb₃AuO, and Rb₃BrO are 0.72 eV, 0.80 eV, 0.15 eV, and 0.29 eV, respectively. The study also investigated the mechanical properties of the antiperovskite structures, including elastic constants, bulk modulus, and shear modulus to provide insights into their mechanical stability and durability. Their Pugh’s ratio (B/G) is below 1.75 and negative Cauchy pressure indicates these compounds are brittle. And machinability index B/C₄₄ > 1.5 implies excellent lubricating properties. This phenomenon extends the potential industrial application of materials with specific mechanical integrity to their structural components. Additionally, the study investigated the optical properties of the A₃BO antiperovskite compounds, including the dielectric function, loss function, reflectivity, conductivity, refractive index, and absorption spectra. These findings provide a comprehensive understanding of how these materials interact with light, which could be useful in the development of optoelectronic devices. Overall, this DFT study provides significant insights into the multifaceted properties of A₃BO antiperovskite compounds, laying the groundwork for further experimental exploration and facilitating the targeted design of materials with tailored properties for specific technological applications.