Modern parameter-free band-structure calculations are applied to the uppermost valence bands near the Γ point. They are based on a nonlocal exchange-correlation starting point for the iteration of the quasiparticle equation and include spin-orbit interaction. The Ga 3d and In 4d electrons remarkably influence the valence-band splittings. Quasiparticle effects shrink the crystal-field splitting Δcf for GaN and increase the inverted Γ1 - Γ5 distance for AlN. Beyond the quasicubic approximation, we find a small anisotropy of the spin-orbit splittings. While for AlN Δso does only weakly depend on the crystal structure, variations are found between zinc blende and wurtzite for GaN or InN.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)