Abstract
Combining electron paramagnetic resonance (EPR) spectroscopy and first-principles density functional theory calculations we have identified the carbon monovacancy center and a second carbon vacancy-related defect, the carbon vacancy–carbon antisite defect in -SiC. In close analogy to the vacancy in silicon, the carbon vacancy in -SiC with its four potentially equivalent silicon dangling bonds shows a strong Jahn-Teller effect, confirming previously predicted negative- properties. High-temperature annealing (above 700 °C) of electron or proton irradiated samples anneals out the primary silicon monovacancies and generates a new defect, which we assign to the carbon vacancy–carbon antisite complex. As predicted by theory, this defect is the result of a structural instability of the silicon vacancy in the positive charge state, which transforms at high temperatures according to . Both defects are deep donors and thus not suitable for achieving semi-insulating properties.
- Received 31 January 2020
- Revised 10 April 2020
- Accepted 20 April 2020
DOI:https://doi.org/10.1103/PhysRevB.101.184108
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