Pulsed EPR studies of Phosphorus shallow donors in diamond and SiC

Phosphorus shallow donors having the symmetry lower than Td are studied by pulsed EPR. In diamond:P and 3C-SiC:P, the symmetry is lowered to D2d and the density of the donor wave function on the phosphorus atom exhibits a predominant p-character. In 4H-SiC:P with the site symmetry of C3v, the A1 ground state of the phosphorus donors substituting at the quasi-cubic site of silicon shows an axial character of the distribution of the donor wave function in the vicinity of the phosphorus atom.