EMPIRICAL TIGHT-BINDING BAND-STRUCTURE OF ZINCBLENDE NITRIDES GAN, ALN, AND BN

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