Ab-initio study of the structural, electronic and optical properties of BSb (110) and (100) surfaces

In the present study, the structural, electronic and optical properties of BSb bulk, BSb (110) and (100) surfaces were investigated. The calculations were performed by using Full-Potential Linear Augmented Plane Wave (FP-LAPW) in Density Functional Theory (DFT) framework with various exchange-correlation functionals. Some surface properties such as surface energies, the work functions, surface relaxation, band structures and optical properties of cubic BSb (110) and (100) nano-slabs were studied. The (100) surface of cubic BSb has B- and Sb-terminations while the (110) surface has only one termination. The surface properties of all the terminations were presented and discussed. Moreover, some bulk properties such as structural, electronic, band structure and optical properties of BSb compound were investigated for comparison. The obtained band gap for the BSb (110) nano-slab was 0.38 eV while the BSb (100) nano-slab showed a metallic behavior. Moreover, the surface states of the slabs were identified. The real and imaginary parts of the dielectric function of the BSb (110) nano-slab were also calculated and compared with bulk results.