Radiation damage induced by 2 MeV protons in CdTe and CdZnTe planar detectors

An experimental investigation of the radiation damage induced on CdTe and CdZnTe semiconductor detectors has been performed by exposing a set of samples to increasing doses of 2 MeV protons produced by a 1.7 MV Tandetron accelerator. The modifications in the detector performances have been studied through the dark current measurements and spectroscopic response analyses at low and medium energies. The deep levels of the materials have been investigated by means of Photo Induced Current Transient Spectroscopy analyses. The evolution of some important parameters (energy resolution, charge collection efficiency, leakage current, activation energies and capture cross-section of deep level defects) have been monitored with respect to increasing proton exposures and the results obtained give us some important indications on the modifications of the material properties as well as on the performances degradation of the detectors.