Structural and Electronic Properties of Zinc Blende-type Nitrides BxAl_1–xN

Abstract

First principles total energy calculations were carried out to investigate structural and electronic properties of zinc blende-type AlN, BN and BxAl 1−x N solid solutions. We have calculated the lattice parameters, bulk modulus, pressure derivative, and BxAl 1−x N band-gap energy for zinc blende-type crystals of the compositions x = 0, 0.25, 0.5, 0.75, 1. The results show that the direct energy gap Γ 15 V →Γ 1 c shows a strong nonlinear dependence on the concentration x. For high boron contents (x > 0.71), these materials have a phase transition from direct-gap semiconductors to indirect-gap semiconductors (Γ 15 V → X 1 c ). This essential feature indicates that these materials should have very good optical properties at high concentrations of boron compared to those of AlN. Further discussions concern a comparison of our results with results obtained with other available theoretical and experimental methods.