Investigation Of Deep Levels In Semi-Insulating Vanadium-Doped 4h-Sic By Photocurrent Spectroscopy

We measured spectral-resolved photocurrent in a wide range of photon energies from 0.68eV to 4.10eV, current-voltage characteristics, and mid to near-infrared transmittance spectra on a semi-insulating 4H-SiC wafer at room temperature. We identified four deep levels, their energies, and localization radii. The model considers the defects' wavefunction as a linear combination of s- and p-states. Such a linear combination leads to the mixture of dipole allowed and forbidden transitions. The forbidden transitions contribute to a broad photocurrent spectrum, and the allowed transitions appear as sharp photocurrent peaks. The width of photocurrent peaks is related to the localization radius of deep levels. (C) 2021 Elsevier B.V. All rights reserved.