Diffusion and defect reactions between donors, C, and vacancies in Ge. II. Atomistic calculations of related complexes

Abstract

Electronic structure calculations are used to study the stability, concentration, and migration of vacancydonor ͑phosphorus, arsenic, and antimony͒ complexes in germanium, in the presence of carbon. The association of carbon with mobile vacancy-donor pairs can lead to energetically favorable and relatively immobile complexes. It is predicted that the complexes formed between lattice vacancies, carbon, and antimony substitutional atoms are more stable and less mobile compared to complexes composed of vacancies, carbon, and phosphorus or arsenic atoms. Then, with the use of mass action analysis, the relative concentrations of the most important complexes are calculated, which depend also on their relative stability not just their absolute stability. Overall, the theoretical predictions are consistent with experimental results, which determined that the diffusion of vacancy-donor defects is retarded in the presence of carbon, especially in samples with a high concentration of carbon. In addition, the calculations provide information on the structure and the equilibrium concentration of the most important complexes and details of their association energies.

Intrinsic and extrinsic diffusion of indium in germanium

“…This has been concluded from self-and foreign-atom diffusion studies 7,21,22,[27][28][29][30] and confirmed by atomistic calculations. 15,23,[30][31][32][33] In particular, the simultaneous diffusion of self-and dopant atoms in isotopically controlled Ge heterostructures have revealed that vacancies in Ge are mainly doubly negatively charged under intrinsic and n-type doping conditions. 7,34 However, the preferred charge state of V under p-type doping is not known.…”

Concentration of intrinsic defects and self-diffusion in GaSb

“…The efficacy of the approach used in the present study has been recently established by comparing with experimental results. [25][26][27][28][29] …”

Defect interactions in Sn1−xGex random alloys

“…Sn has been found to diffuse in Ge with an activation enthalpy in the range of 2.9-3.26 eV, which can be attributed to a V-mechanism of diffusion. 12 In this context we now investigate the stability of SnV pairs as well as Sn 2 V and SnV 2 complexes in otherwise pure Ge and in Si for comparison. The cluster configurations have previously been reported.…”

“…The significance of vacancies ͑V͒ in the diffusion and defect processes in Ge ͑such as those caused by radiation damage͒ has been the subject of numerous studies. 12,13 The aim of the present work is thus twofold: first, to establish an effective approach to model the structure of Sn 1−x Ge x alloys of high Sn content and second to study the structure of Sn n V m complexes in Ge and thereby demonstrate that the computational method also generates useful results at lower Sn concentrations.…”