Ligand hyperfine interaction at the neutral silicon vacancy in 4H- and 6H-SiC

The silicon vacancy in its neutral charge state (V-Si) has been unambiguously identified in 4H- and 6H-SiC. This was achieved by observation of ligand hyperfine interaction with the four carbon atoms in the nearest-neighbor shell and the twelve silicon atoms in the next-nearest-neighbor shell surrounding the vacancy. The complete hyperfine tensors have been determined for the V-Si(0) center residing at all inequivalent lattice sites in the two polytypes. These are compared with the parameters previously obtained for the negatively charged silicon vacancy.