Photoconductivity in Gold-Germanium Alloys

Photoconductivity has been observed at 77°K and 22°K in $n$- and $p$-type gold-doped germanium. The low-energy thresholds for impurity photoconduction are compatible with the activation energies found by conventional electrical measurements. Quenching effects were found in some $n$-type samples. Prominent quench bands were found at 0.8 and 0.66 ev. The characteristics of the quenching were observed as a function of light intensity, applied voltage and temperature. An interpretation of the quenching data in terms of a hole trap model is suggested.