Density functional theory calculations were used to study the interaction between carbon and isolated substitutional dopants (boron, gallium, aluminium, indium, silicon, tin, nitrogen, phosphorous, arsenic and antimony) and dopant-vacancy pairs in germanium. It was predicted that there was a range of different association preferences, with carbon being strongly bound in some cluster geometries and dopants and unbound in others. If dopant-carbon pairs form they could act as vacancy traps to form larger and bound clusters. As vacancies were important for diffusion and cluster formation in germanium, the results were discussed in view of recent experimental studies.

Effect of Carbon on Dopant-Vacancy Pair Stability in Germanium. A.Chroneos: Semiconductor Science and Technology, 2011, 26[9], 095017