First-principles density functional calculations were used to investigate antisite pairs in 4H-SiC. It was shown that they were likely to be formed in close proximity under ionizing conditions, and possessed a donor level and thermal stability which were consistent with a series of 40 photoluminescent (alphabet) lines. Moreover, the gap vibrational mode of the Si antisite defect was close to a phonon replica of the b1 line and possesses a weak isotopic shift with 13C in agreement with observation.

Alphabet Luminescence Lines in 4H-SiC. T.A.G.Eberlein, C.J.Fall, R.Jones, P.R.Briddon, S.Öberg: Physical Review B, 2002, 65[18], 184108 (4pp)