Results of photoluminescence and Hall effect measurements ofphyphen;type Gehyphen;doped Ga0.60Al0.40As grown by liquid phase epitaxy are reported. The effective segregation coefficient for Ge for growth at 785thinsp;deg;C is estimated to be sim;2times;10minus;3. The photoluminescence spectra at 5.5 K are characterized by two edge emission bands at sim;1.91 and sim;1.88 eV and a broadband at sim;1.55 eV. The edge emission bands are identified to be donorhyphen;acceptor pair recombination bands involving the same donor but two different acceptors. The ionization energy of the donor is estimated to be 50ndash;60 meV and the acceptor ionization energies are estimated to be sim;60 and sim;100 meV for the 1.91hyphen; and 1.88hyphen;eV bands, respectively. The deep acceptor is believed to involve a background impurity, most likely C or Si. It is suggested that the 1.55hyphen;eV band arises from a nexthyphen;nearest neighbor complex consisting of Ge on an arsenic site and an As vacancy. Posthyphen;growth annealing treatment at 830 deg;C is found to decrease the photoluminescence intensity suggesting the presence of annealing induced nonradiative centers.
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