A study was made of the properties of samples of As-rich material which were grown by molecular beam epitaxy, at substrate temperatures of 200 to 400C, and were then annealed at higher temperatures. First-principles calculations revealed a nearest-neighbor complex, which involved an As antisite and a split As interstitial, and which might explain some of the observed changes in the electrical and optical behavior of low-temperature material when it was annealed at temperatures that were slightly above 400C. This complex had a higher energy configuration which was analogous to the metastable state of the isolated antisite. The higher-energy configuration of the complex appeared to be an almost truly metastable state. The localized electronic states for the complex and its higher-energy configuration were characterized.

J.I.Landman, C.G.Morgan, J.T.Schick, A.Kumar, P.Papoulias, M.F.Kramer: Materials Science Forum, 1995, 196-201, 249-54