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, divacancies, and multivacancies. 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 homopolar carbon dangling-bond defects as the leakage causing defects in nanoporous SiC alloys.