Electronic structure calculations were used to study the stability, concentration and migration of vacancy-donor (P, As, Sb) complexes in Ge, in the presence of C. The association of C with mobile vacancy-donor pairs could lead to energetically favorable and relatively immobile complexes. It was predicted that the complexes formed between lattice vacancies, C, and Sb substitutional atoms were more stable and less mobile compared to complexes composed of vacancies, C, and P or As atoms. Then, with the use of mass action analysis, the relative concentrations of the most important complexes were calculated, which also depended upon their relative stability; not just their absolute stability. Overall, the theoretical predictions were consistent with experimental results, which determined that the diffusion of vacancy-donor defects was retarded in the presence of C; especially in samples with a high concentration of C. In addition, the calculations provided information on the structure and the equilibrium concentrations of the most important complexes and the details of their association energies.

Diffusion and Defect Reactions between Donors, C, and Vacancies in Ge II - Atomistic Calculations of Related Complexes. A.Chroneos, R.W.Grimes, B.P.Uberuaga, H.Bracht: Physical Review B, 2008, 77[23], 235208 (7pp)