Bulk structure of Si2BN predicted by computational approaches

Abstract

Recently, the theoretically predicted single-layer silicon boron nitride (Si 2 BN) has gained wide scientific interests. However, there still lack of studies on its bulk counterpart. In this work, we computationally predicted the bulk structures of Si 2 BN by combining particle swarm optimization (PSO) algorithm with first-principles calculations. For the PSO screened structures, we confirmed that the α-phase (α-Si 2 BN) is the most probable structure of bulk Si 2 BN, by evaluating from crystal symmetry, average atomic formation enthalpy and phonon dispersion spectrum. The electronic band structure of α-Si 2 BN indicates that it's semiconducting with an ultra-narrow indirect bandgap (0.02 eV). Moreover, investigations on mechanical and thermal properties reveal that the α-Si 2 BN exhibits considerable hardness, ultra-high Debye temperature (1001 K ) and ultra-high melting point (2600 K), which holds great potential as high-temperature resistant material. • We predicted new bulk Si 2 BN by PSO algorithm and first-principles calculations. • α-phase Si 2 BN is semiconducting with an ultra-narrow indirect bandgap. • α-phase Si 2 BN is a candidate as high-temperature resistant material.