Formation and migration energies of the vacancy in Si calculated using the HSE06 range-separated hybrid functional

Abstract

To overcome deficiencies of conventional density functional theory (DFT) utilizing the standard approximation for the exchange-correlation, the revised Heyd-Scuseria-Ernzerhof screened hybrid functional (HSE06) has been used for calculating the formation and migration energies of the vacancy in Si. It is demonstrated that the hybrid approach gives a much more accurate electronic description of the bulk and the vacancy. The correct description of the band gap and the donor transition levels obtained with the HSE06 functional builds confidence in predictions of the vacancy acceptor states. The calculated migration energies of the vacancy with different charge states agree well with low-temperature annealing measurements and, together with formation energies, provide an excellent estimate of the activation energy of vacancy-mediated self-diffusion in silicon.