Ligand hyperfine interaction at the neutral silicon vacancy in 4H- and6H−SiC

The silicon vacancy in its neutral charge state ${(V}_{\mathrm{Si}})$ has been unambiguously identified in 4H- and $6H-\mathrm{SiC}.$ 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 $V_{\mathrm{Si}}^0$ 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.