Photoabsorption effects in low temperature electron-irradiated Germanium

Photoconductivity measurements performed under carefully controlled conditions have revealed that the dominant defects in low temperature, electron irradiated n-type Ge are optically active, double-acceptor type defects which thermally anneal at a temperature around 65°K. The stability of these defects is sensitive to temperature, background light levels, irradiation fluenced and fluxes, and probably impurity type and concentration. It is concluded from the results of this and other studies that the optically active defect is probably an isolated vacancy.