Abstract:
Using both the Perdew–Burke–Ernzerhof (PBE) functional and the hybrid functional of Heyd–Scuseria–
Ernzerhof (HSE06), the metastability of the carbon-substitutional–carbon-interstitial (CsCi) defect in
silicon has been investigated within density functional theory using the two experimentally proposed
configurations of the defect. While the PBE functional predicted the defect complex to have both donor
and acceptor levels, it did not predict any form of charge-state controlled metastability as was observed
experimentally. In the case of HSE06 functional, the defect was found to exhibit charge-state controlled
metastability in the 0 and 1 charge states with no metastability predicted for +1 charge state. The
calculated binding energies for the neutral charge state indicate that the defect is a stable bound defect
complex.
