Epitaxial silicon carbide is likely to contain hydrogen and vacancies (V); therefore, V+nH complexes are likely to influence its electronic properties. Using ab initio calculations we show that neutral and positive H atoms are trapped by carbon vacancies (VC) in three-center bonds with two Si neighbors. The double positive charge state of VC+H is not stable in equilibrium and in the triply positive state H binds only to one of the Si neighbors. At most two H atoms can be accommodated by a single VC. The VC+nH complexes have donor character and exhibit rather atypical vibration modes for Si-H bonds. Occupation levels and spin distributions were calculated and compared for VC+H and VC.
ASJC Scopus subject areas
- Physics and Astronomy(all)