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

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 (O C ), and oxygen-vacancy (O C V Si ) complex as prominent defects in n -type conditions. Among them, O C V Si was predicted as a spin-1 defect with NIR emission in a previous study. On the basis of the obtained results, we discuss the possible spin decoherence sources when employing O C V Si as a spin-to-photon interface.