Photoexcitation-electron-paramagnetic-resonance studies of the carbon vacancy in 4H-SiC

Photoexcitation-electron-paramagnetic-resonance (photo-EPR) studies were performed on p-type 4H-SiC irradiated with 2.5 MeV electrons. At W-band frequencies (∼95 GHz) different EPR spectra could be well separated, allowing a reliable determination of the ground state levels of the associated defects. The photo-EPR results obtained for the positively charged carbon vacancy $({\mathrm{V}}_{\mathrm{C}}^{+})$ can be explained by a deep donor model with the (+/0) level located at $\text{(1.47±0.06)\hspace{0.17em}}\mathrm{eV}$ above the valence band.