Vacancy-associated Te sites in GaAs

Defect structures, observed by ${}_{}{}^{129}{}_{}{}^{}\mathrm{I}$ Mössbauer spectroscopy in high-dose Te-doped GaAs, are identified by a reference study of the semiconducting compound ${\mathrm{Ga}}_2$ ${\mathrm{Te}}_3$. The formation of ${\mathrm{Te}}_{\mathrm{As}}$-${\mathit{V}}_{\mathrm{Ga}}$ complexes (tellurium atoms quasisubstitutional on an As site with a gallium vacancy in the first-neighbor shell) is proposed, in agreement with theoretical predictions. The relevance of this assignment in relation to the earlier proposed Te DX configuration is also discussed.