Neutron irradiation-induced defects in Cd_0.9Zn_0.1Te:In crystals

The survivability of γ-ray detector in radiation environment of energetic neutrons is a key issue for its application in spacecraft, accelerator, nuclear reactor, etc., especially for the case of CdZnTe detectors. Nevertheless, very little attention has been paid to the radiation damage mechanism of detectors and the evolution of radiation-induced defects in the detector medium, i.e. Cd_0.9Zn_0.1Te:In crystals. We proposed and simulated the radiation defects type and amount of Cd_0.9Zn_0.1Te:In crystals after neutron irradiation with the Monte-Carlo software SRIM. The calculated data are also compared with experimental results of detector performance and the crystal defects obtained using thermally stimulated current (TSC)measurement. We also discuss the influence of defect concentrations on crystal resistivity and detector energy resolution. It was shown that the concentration of vacancies, interstitials, and their related defects increased after neutron irradiation, which could be the reason for the worsening of Cd_0.9Zn_0.1Te:In γ-ray detector performance after the neutron irradiation.