First-principles study of the electronic structure of boron-arsenide under strain

This study systematically investigates the modulation of the electronic structure of boron arsenide (BAs) under deep strain by using first-principles calculations. It is found that the strain modulation of the band gap is anisotropic. Tensile strain along the [110] direction first increases the band gap to 1.365 eV and then gradually closes it; compressive strains along the [110] and [111] directions lead to a linear decrease in the band gap; compressive strain along the [001] direction causes a two-stage decrease in the band gap. Isotropic hydrostatic pressure produces linear changes in the lattice parameters, unit cell volume, and band gap of BAs, with the band gap decreasing under compression and increasing under tension. This study provides a theoretical basis for strain-based modulation of the BAs band gap and understanding its anisotropic mechanical behavior, indicating that BAs has broad application prospects in the field of next-generation optoelectronic and valleytronic devices.