Infrared spectra and electron spin resonance of vanadium deep level impurities in silicon carbide

Trace impurities of vanadium in Lely-grown silicon carbide single crystals have been detected by their strong, polytype-specific photoluminescence in the 1.3–1.5 μm near-infrared spectral range, as well as by infrared absorption. The spectra arise from the intra-3d-shell transitions 2E(3d1)→2T2(3d1) of V4+Si(3d1). Electron spin resonance reveals that VSi in SiC acts as a deep acceptor, V4+Si(3d1)/V3+Si(3d2)−̂A0/A−, and possibly also as a deep donor. The role of vanadium as minority-carrier lifetime killer in SiC-based optoelectronic devices is suggested from these data.