A Mossbauer Study of Fe Impurity Atoms in Gallium Arsenide

摘要

Mossbauer emission spectroscopy of the ~(57)Co(~(57m)Fe) isotope was used to find the dependence of the charge state of Fe impurity atoms in GaAs on the Fermi level position in the band gap. Neutral and ionized states of impurity atoms both in the surface region (where an impurity exists in the form of isolated substitutional atoms) are identified. In the bulk region of partially compensated samples, fast electron exchange between neutral and ionized acceptor Fe centers performed by holes via the valence band is revealed.