Laplace transform deep-level transient spectroscopy was used to study the acceptor levels of Pt and Au which were diffused into dilute (less than 5%Ge) alloys. It was shown that Ge atoms in the first and second shells of atoms, which surrounded the impurity, perturbed the electronic properties of the Au and Pt acceptor defects. The magnitude of the splitting which was caused by one Ge atom in the first shell was equal to about 0.035eV in both cases. The spectral distributions indicated an overpopulation of Ge-perturbed sites as compared with randomly occupied sites. This could be quantitatively interpreted in terms of an enthalpy difference of 0.06eV between configurations with zero or one Ge atom in the first shell which surrounded the impurity.

Alloy Splitting of Gold and Platinum Acceptor Levels in SiGe L.Dobaczewski, K.Gościński, K.Bonde Nielsen, A.Nylandsted Larsen, J.Lundsgaard Hansen, A.R.Peaker: Physical Review Letters, 1999, 83[22], 4582-5