First-principles calculations for optoelectronic properties of AlSb and GaSb under influence of spin–orbit interaction effect

Abstract

In this article, we present the first-principles calculations for electronic and optical properties of AlSb and GaSb in the zinc blende phase using density functional theory. These calculations were carried out using the full potential-linearized augmented plane wave method embedded in WIEN2K package. Perdew–Burke–Ernzerhof and modified Becke–Johnson approximations with and without addition of spin–orbit interaction (SOI) effect were taken as exchange-correlation potentials. With SOI effect, we found that AlSb has an indirect bandgap (Г − Δmin) of 1.66 eV and GaSb has a direct bandgap (Г–Г) of 0.812 eV. These results are in good agreement with experimental data and are far better than the theoretical results published elsewhere. We also calculated the dielectric functions, refractive indexes, reflectivities, energy loss functions, optical conductivities and absorption coefficients as a function of frequency in order to investigate the optical responses of AlSb and GaSb. Also, the calculated critical point energies with SOI effect are consistent with the experimental results.