Random potential relief and extrinsic photoconductivity of compensated germanium

Abstract

A photoconductivity spectrum normalized to the optical absorption of compensated germanium is simulated at low temperatures kT≪W (where W denotes the energy scale of the random potential that stems from impurity Coulomb interaction). By fitting the simulated spectrum to the experimental data, the value of W and the occupancy of the shallow-donor impurity band are estimated. A weak energy dependence of the mean free path of electrons in the random potential relief is inferred.