Ab initio calculations of electronic band structure and charge densities of zinc blende-type GaN, BN and their solid solution B0.5Ga0.5N

First principles calculations of the electronic band structures of zinc blende-type GaN and BN and their 1 : 1 mixture B0.5Ga0.5N were carried out within DFT using the augmented plane wave method with both GGA and LDA approximations for the effects of exchange and correlation. Equilibrium lattice constants were determined from the total-energy minimization method. The results are compared with those of previous calculations and with experimental measurements. In agreement with these data, ZB-BN is an indirect (Γ →X) wide-gap semiconductor (4.35 eV) while ZB-GaN has a direct gap of 1.9 eV atΓ . For ZBB0.5Ga0.5N we predict a direct band gap of 3.35 eV. Electron charge densities are computed for the unit cell, and ionicity factors are derived for all systems