A study was made of the absence of decorating As precipitates from dislocations in Te-doped material. Such precipitates were found when other dopants were used. By using transmission electron microscopy, it was seen that the dislocations in Te-doped samples were always tangled and were surrounded by clouds of extrinsic loops. However, they were not decorated with As precipitates. Dilute Sirtl-etching results supported the conclusion that the regions which contained loop clusters around dislocations were enriched in TeAsVGa acceptor complexes that formed due to the diffusion of Te towards the dislocations. The formation of TeAsVGa caused an undersaturation of the Ga vacancies, and therefore the production of a supersaturation of Ga interstitials. The latter was the driving force for the observed formation of extrinsic loops and of dislocation tangling via climb. Such processes consumed As interstitials, and the latter were thus no longer available for the formation of decorating As precipitates.

On the Absence of Decoration As Precipitates at Dislocations in Te-Doped GaAs. C.Frigeri, J.L.Weyher, J.Jiménez: Journal of Physics - Condensed Matter, 2000, 12[49], 10335-42