Native defects and complexes in SiC

Prototypical native defects, in particular monovacancies, are studied using ab initio density functional theory and the local spin-density approximati on. Several properties such as the energetics, geometry, electronic structu re, and spin states are discussed regarding their dependence on the chemica l nature, the preparation conditions, and the polytype of the SiC crystal. Consequences of the defects are derived for the doping behaviour, electrica l properties, and photoluminescence spectra.