| Abstract: | We present systematic measurements of CPM on two independent series of slightly phosphorous and boron doped films. For “n-type” samples of both series, the CPM deep defect absorption is proportional to the square root of the gas dopant ratio. For these samples we discuss the influence of Fermi level on the CPM spectra. For slightly “p-type” samples, CPM deep defect absorption as evaluated by CPM becomes higher than the corresponding PDS-values. This fundamental problem can be traced back to the violation of two basic conditions necessary for a correct evaluation of the absorption from CPM measurements: (1) the power law exponent γ (Rose factor) of the photoconductivity must be spectrally independent, and (2) the generation rate G, which corresponds to the CPM photocurrent, also has to be spectrally independent. Further, we compare the annealed and the “saturated” light soaked states of selected slightly doped samples and an undoped sample: the variations in the CPM deep defect absorption and in photoconductivity due to light-soaking are discussed. |
