Germanium-Doped Gallium Arsenide

Germanium-doped GaAs crystals were grown on GaAs seeds from Ga solution. The properties of the Ge-doped GaAs layers were examined by Hall effect measurements from 20° to 400°K and by photoluminescence measurements between 12° and 300°K. It was found that Ge-doped GaAs is always p-type when grown at 900°–875°C from Ga solution containing 56 at.% or less Ge. The temperature dependence of the Hall coefficient and the photoluminescence experiment indicated an acceptor energy level of 0.035 and 0.038 eV respectively. It was also found that at least 85% of the Ge was present as an acceptor in the GaAs crystals when the growth solution contained two atom percent or less Ge.