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

Journal Article · Thu Nov 21 04:00:00 EST 2013 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4829697· OSTI ID:22258771

Fuhr, J. D. ^[1]; Ventura, C. I. ^[1]; Barrio, R. A. ^[2]

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1. Centro Atómico Bariloche-CNEA and CONICET, Av. Bustillo 9500, R8402AGP Bariloche (Argentina)
2. Instituto de Física, U.N.A.M., 01000 Mexico, D.F. (Mexico)

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.

• OSTI ID: 22258771
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 19 Vol. 114; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ABUNDANCE
ALLOYS
DEFECTS
DIFFUSION BARRIERS
INTERACTIONS
SEGREGATION
SEMICONDUCTOR MATERIALS
VACANCIES