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Title: Theoretical study of defect formation during the initial stages of native-oxide growth on GaSb (001)

The formation of defects during the initial stages of native-oxide growth on the GaSb (001)-α(4 × 3) surface has been studied computationally using spin-unrestricted density functional theory. It is found that insertion into a Ga-Sb adatom dimer to form a peroxo Ga-O-O-Sb bridge is the most energetically favorable process with insertion into Ga-Sb back-bonds being somewhat less so. A Ga-O-O-Ga bridge between dimers is also favorable, but Sb-O-O-Sb bridges show little if any stability. In the course of analyzing molecular adsorption, a particularly reactive site has been identified that leads to O{sub 2} dissociation with little or no barrier. This process is initiated in the vicinity of an Sb-Sb dimer in the terminating layer and leads to sub-surface Ga and Sb defect sites (i.e., coordinatively unsaturated atoms) and to strained Ga-Sb bonds that may be susceptible to further O{sub 2} attack. However, the defects formed in these reactions do not produce states in the gap.
Authors:
 [1]
  1. Electronics Science and Technology Division, U.S. Naval Research Laboratory, Washington, DC 20375 (United States)
Publication Date:
OSTI Identifier:
22261558
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 14; Other Information: (c) 2014 U.S. Government; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CRYSTAL GROWTH; DEFECTS; DENSITY FUNCTIONAL METHOD; DIMERS; GALLIUM ANTIMONIDES; OXIDES