Dangling bond defects in SiC: an ab initio study

We report first-principles microscopic calculations of the properties of defects with dangling bonds in crystalline 3C-SiC. Specifically, we focus on hydrogenated Si and C vacancies, di-vacancies and multi-vacancies. The latter is a generic model for an isolated dangling bond within a bulk SiC matrix. Hydrogen serves to passivate electrically active defects to allow the isolation of a single dangling bond defect. We used hybrid density functional methods to determine energetics and electrical activity. The present results are compared to previous 3C-SiC calculations and experiments. Finally, we identify homo-polar carbon dangling bond defects as the leakage causing defects in nano-porous SiC alloys.