Strain-tunable electronic structure, optical and thermoelectric properties of BAs

Abstract

Strain engineering stands as a reliable method for tailoring the physicochemical properties of materials to achieve desired performance. However, the effects of strain on the physicochemical properties of BAs remain unclear, impeding the comprehensive understanding of its practical performance. Here, employing first-principles calculations coupled with semiclassical Boltzmann transport theory, we investigate the dynamic stability, mechanical stability, electronic structure, and thermoelectric properties of cubic boron arsenide (BAs) under various strains. The results demonstrate that BAs maintains excellent stability throughout the triaxial strain range. The electronic structure of BAs is less affected by strain. Young's modulus and Poisson's ratio show a corresponding linear increase when the compression strain increases. The optical absorption coefficient in the visible region of BAs under tensile strain showed an overall increasing trend, and the optical absorption coefficient in the visible wavelength region of BAs under 5% tensile strain was as high as 2×105 cm-1. The thermoelectric properties of BAs under tensile strain have been improved, and the ZT value of BAs under 5% tensile strain at 1500 K has been increased to 0.6. The research findings address the gaps in understanding the properties of BAs under strain and provide theoretical support for its applications in the fields of thermoelectrics and optoelectronics.