We study the energetics of various point defects in silicon using ab initio density-functional methods. The formation free energies are calculated from the harmonic phonon frequencies, which are determined from ab initio density-functional perturbation theory calculations. We deduce the concentrations of defects as a function of temperature and compare them with experimental estimates. The localized vibrational modes associated with the various defects are described.

• Received 21 July 2003

DOI:https://doi.org/10.1103/PhysRevB.68.235205