Analysis of photoinduced current transient spectroscopy (PICTS) data by a regularization method

In order to get information about the deep levels of a semiconductor from photoinduced current transient spectroscopy (PICTS), the thermal relaxation times must be calculated from the time dependence of the photoinduced current. If the deep levels have a bandwidth their contribution to the photoinduced current must be described by a relaxation time spectrum. In this case a regularization method as implemented, for example, in the program FTIKREG should be used for the calculation. The advantages of the regularization method in comparison with the customary two-gate technique are demonstrated by the analysis of simulated and real experimental data. The experimental data have been obtained from a high-resistivity CdTe:Br crystal.