Density functional study on helium and hydrogen interstitials in silicon carbide

Silicon carbide with various defects such as carbon or silicon vacancies, anti-sites, and helium or hydrogen interstitials are studied in detail by ab initio calculations. The energy minimized structures of vacancies and helium or hydrogen interstitials are investigated. The calculated electronic spectra explain well some of the important features of silicon carbide observed in experiments. The phonon spectra of silicon carbide with hydrogen interstitials between silicon and carbon bond are calculated, and the frequency of the hydrogen–carbon stretching mode is consistent with experiments.

► Silicon carbide with various defects is studied by ab initio calculations.
► Energy minimized structures of vacancies and H and He interstitials are investigated.
► Phonon frequency of the H–C stretching mode is consistent with experiments.