Magnetic circular dichroism and electron spin resonance of the A− acceptor state of vanadium, V3+, in 6H-SiC

The magnetic circular dichroism (MCD) of the absorption has been studied in a 6H-SiC crystal highly contaminated with vanadium, V. In addition to previously reported MCD absorption lines of V4+(3d1), new sharp MCD lines have been observed near 2.0 μm. The chemical nature and origin of these lines were identified by MCD-detected electron spin resonance. They arise from V3+ (3d2) and most likely correspond to the 3A2 → 3T2 crystal-field absorption. The positions of the V3+V4+ acceptor level and the V4+V5+ donor level are discussed. The possibility of growing high-resistivity SiC crystals by deliberate vanadium doping is pointed out.