Oxygen-related defects in 4H-SiC from first principles

Abstract We investigated the abundance, structures, energy levels, and spin states of oxygen-related defects in 4H-SiC on the basis of first principles calculations. We applied a hybrid functional in the overall calculations, which gives reliable defect properties, and also considered relevant defect charge states. We identified the oxygen interstitial (O i,1), substitutional oxygen (OC), and oxygen-vacancy (OC V Si) complex as prominent defects in n-type conditions. Among them, OC V Si was predicted as a spin-1 defect with near-infrared emission in a previous study. On the basis of the obtained results, we discuss the possible spin decoherence sources when employing OC V Si as a spin-to-photon interface.