First-principles study of structural, electronic and optical properties of AlN, GaN, InN and BN compounds

Nitride semiconductor compounds have been occupying the center of scientific attention due to their extraordinary physical properties for many years. In this study, the structural, electronic and optical properties of aluminium nitride (AlN), gallium nitride (GaN), indium nitride (InN) and boron nitride (BN) have been investigated by using full potential linear augmented plane waves plus local orbital’s method as embodied in WIEN2k code within the framework of density functional theory. These properties of the above-mentioned semiconductor compounds within two phases (wurtzite and zinc blende) have been calculated by the local density approximation, generalized gradient approximations and the recently developed modified Becke and Johnson exchange potential plus local-density approximation methods. In this study, the calculations show that the present results of the above said compounds for the lattice constant, bulk modulus and its pressure derivative are consistent with the experimental results. The energy band gaps obtained from modified Becke and Johnson exchange potential plus local-density method are in very close agreement with the experimental results. Moreover, modified Becke and Johnson exchange potential plus local-density approximation method shows improvement over the local density approximation and generalized gradient approximation. As for optical properties, it was found that the local density approximation and generalized gradient approximation results of static dielectric constant, static refractive index and reflectivity are in agreement with the experimental values.