Recent experimental and theoretical studies had revealed that dopants in germanium clustered with lattice vacancies (V). The existence of these larger clusters was important as they could contribute to the low activation of dopants in Ge. With the use of electronic structure calculations, a study was made of the . binding energies of clusters formed with the association of dopant atoms and vacancies. As an example of the kinetics of such clusters the diffusion of two phosphorus-vacancy (P2 V) clusters via the ring mechanism of diffusion in predicted. These P2 V clusters were important as they could act as precursors for the formation of the larger P3 V and P4 V clusters. The present study provided information on the structure of clusters and was consistent with recent experimental results, which indicated that the formation of clusters in heavily doped Ge was possible. In agreement with experiment, it was predicted that the diffusion of P V pairs was retarded by the addition of a further P atom.

Dopant-Vacancy Cluster Formation in Germanium. A.Chroneos: Journal of Applied Physics, 2010, 107[7], 076102