Theory of gold-hydrogen complexes in silicon

Spin-polarised local density functional cluster calculations are carried out on substitutional Au and Au-H_n complexes in Si. Slater's transition argument and Janak's theorem are combined to discuss the donor-acceptor levels of the defects and the results are compared with experiment. The calculations give a good account of the donor/acceptor levels of Au and the Au-H pair. They confirm that the G1, G2 and G4 levels are due to Au-H. Au-H₃ is found to be an electrically inactive defect and may be identified with the passive defect found experimentally.