First-principles Study of the Impact of Hydrogen Passivation on the Charge State Transition Levels of the CiOi(Sii)n Defect Complexes in Silicon

Abstract

Density functional theory (DFT) with the Heyd-Scuseria-Ernzerhof hybrid functional has been used to predict the stability, formation energy, geometric structure, and the charge state transition levels of the CiOi(Sii)n (i = interstitial) defect complex in silicon for n = 0, 1, 2. The effect of hydrogen passivation on the properties of the CiOi(Sii)n defect complex is also investigated. The results for the binding energies confirm the stability of the defect complexes at neutral charge state. The charge state transition levels show that CiOi induces a shallow donor level and a deep acceptor level. The CiOiSii and CiOi(Sii)2 however induced deep donor levels. After hydrogen passivation, the acceptor level of the CiOiSii and the CiOi(Sii)i defect complexes disappear and the donor levels for all the defect complexes move deeper in the band gap.