ARSENIC INTERSTITIALS AND INTERSTITIAL COMPLEXES IN LOW-TEMPERATURE-GROWN GAAS

First-principles molecular-dynamics calculations have been used to cal culate the formation energy of the lowest-energy As interstitial confi guration relative to the formation energies of As antisites and Ga vac ancies in As-rich GaAs, and to identify and study the properties of en ergetically favorable complexes containing one As antisite and one As interstitial. It is suggested that the electronic and optical properti es of the antisite-interstitial complexes match the properties of the defects responsible for the dominant donor band in some samples grown around 350 degrees C.