Electronic properties and defect levels induced by group III substitution–interstitial complexes in Ge

Abstract

In this report, we used the hybrid density functional theory to systematically investigate the formation of substitution-interstitial complex defects formed by group III (B, Al, Ga and In) atoms in Ge for charge states −2, −1, 0, +1 and +2 as a function of the Fermi level. Under equilibrium conditions, the substitution-interstitial complexes in Ge formation energies were found to be relatively lower than 7.00 eV and stable with respect to their binding energies. For the neutral charge state, the Al Ge Ga i complex (where Al Ge and Ga i represent Al substitution in Ge and Ga interstitial, respectively) is the most stable defect with