Photoconductivity in Manganese-Doped Germanium

Impurity photoconduction has been observed in $n$- and $p$-type Mn-doped germanium at low temperatures. The spectra are consistent with the published ionization energy values determined from conductivity data High-resistivity $n$-type samples show high intrinsic photosensitivity and long response times at low temperatures. In such samples the intrinsic photocurrent could be quenched by a factor of ∼${10}^4$ with light in the 0.3 to 0.7 ev range. Intrinsic photoconductivity was found to vary more rapidly than linearly with light intensity over a limited range.