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Title: Formation of non-substitutional β-Sn defects in Ge{sub 1−x}Sn{sub x} alloys

Although group IV semiconductor alloys are expected to form substitutionally, in Ge{sub 1−x}Sn{sub x} this is true only for low concentrations (x < 0.13). The use of these alloys as a narrow gap semiconductor depends on the ability to produce samples with the high quality required for optoelectronic device applications. In a previous paper, we proposed the existence of a non-substitutional complex defect (β-Sn), consisting of a single Sn atom in the center of a Ge divacancy, which may account for the segregation of Sn at large x. Afterwards, the existence of this defect was confirmed experimentally. In this paper we study the local environment and the interactions of the substitutional defect (α-Sn), the vacancy in Ge, and the β-Sn defect by performing extensive numerical ab initio calculations. Our results confirm that a β-Sn defect can be formed by natural diffusion of a vacancy around the substitutional α-Sn defect, since the energy barrier for the process is very small.
Authors:
 [1] ;  [2] ;  [1] ;  [2] ;  [3]
  1. Centro Atómico Bariloche-CNEA and CONICET, Av. Bustillo 9500, R8402AGP Bariloche (Argentina)
  2. (Argentina)
  3. Instituto de Física, U.N.A.M., 01000 Mexico, D.F. (Mexico)
Publication Date:
OSTI Identifier:
22258771
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 114; Journal Issue: 19; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ABUNDANCE; ALLOYS; DEFECTS; DIFFUSION BARRIERS; INTERACTIONS; SEGREGATION; SEMICONDUCTOR MATERIALS; VACANCIES