Empirical tight-binding band structure of zinc-blende nitrides GaN, AlN, and BN

The electronic band structure and density of states for zinc-blende nitrides GaN, ALN, and BN are reported using an sp(3)s* tight binding method. The large hand gap found for these compounds is analyzed in terms of chemical and volume deformation effects. The calculated ionicity agrees with the Phillips scale and shows a strongly ionic character for GaN and AIN, while BN is found more covalent.