NEGATIVELY CHARGED SI VACANCY IN 4H SIC - A COMPARISON BETWEEN THEORYAND EXPERIMENT

We use electron paramagnetic resonance and electron nuclear double res onance to identify the negatively charged Si vacancy in neutron-irradi ated 4H SIG. The identification is based on resolved ligand hyperfine interactions with carbon and silicon nearest and next nearest neighbor s and on the determination of the spin state, which is S = 3/2. The ma gnetic resonance parameters of V-Si(-) are almost identical for the po lytypes 3 C, 4H. and 6H. The experimental findings are supported by th eoretical ligand hyperfine interaction data based on a total-energy ca lculation using the standard local-density approximation of the densit y-functional theory.