  We have studied the electronic structure of InN and GaN employing G0W0
calculations based on exact-exchange density-functional theory. For InN our
approach predicts a gap of 0.7 eV. Taking the Burnstein-Moss effect into
account, the increase of the apparent quasiparticle gap with increasing
electron concentration is in good agreement with the observed blue shift of the
experimental optical absorption edge. Moreover, the concentration dependence of
the effective mass, which results from the non-parabolicity of the conduction
band, agrees well with recent experimental findings. Based on the quasiparticle
band structure the parameter set for a 4x4 kp Hamiltonian has been derived.

Materials Science