First principle studies on the structural and optoelectronic properties of boron antimonide: A promising candidate for photovoltaic applications

Abstract

The search for a superior material with greater energy conversion efficiency as compared to the existing material systems for photovoltaic applications has always been the quest of research community. A systematic study of the optoelectronic properties of zinc blende (ZB) phase boron antimonide (BSb) using the full-potential linearized augmented plane wave (FPLAPW) basis sets in the density functional theory (DFT) with the Modified Becke-Johnson (mBJ) exchange correlation (XC) potential is carried out to investigate its potential as a photovoltaic material. Structural optimization is done considering the Perdew-Burke-Ernzerh of generalized gradient approximation (PBEsol) XC functional. Taking into account the optimized lattice constant of 5.2306 Å, which is consistent with previous experimental as well as theoretical findings, the fundamental electronic and optical parameters such as electronic density of state (DOS), band diagram, complex-dielectric function, refractive index, extinction coefficient, and optical absorption coefficient are computed. The effective mass of charge carriers for conduction and valence band have been calculated along the crystallographic symmetric directions. The calculated wider direct-gap (Γ−Γ) of 2.8048eV, and a comparatively narrower indirect-gap (X−Γ) of 0.99694eV are in excellent agreement with the available literature. These distinct and fascinating optoelectronic properties of BSb can be very useful for realizing solar cells with better energy conversion efficiency.