Study on radiation damage effects on CdZnTe detectors under 3 MeV and 2.08 GeV Kr ion irradiation

The survivability of CdZnTe gamma ray detectors, when exposed to energetic particles in a radiation environment, is a key issue for their application. Nevertheless, very little attention has been paid to the irradiation particle energy influences on CdZnTe detector performance. The effects of 3 MeV and 2.08 GeV Kr ion irradiation at fluences of 1 × 1012 ions/cm2 on CdZnTe detector performance are investigated. Variations in performance were determined by comparing pre- and post-irradiation detector current-voltage (I–V) curves and the measured energy spectrum of a 59.5 keV gamma ray source, 241Am. Monte-Carlo simulations of the irradiation process were performed using SRIM software to help explain the observed changes in detector performance. Thermally stimulated current measurements were used to reveal crystal defects newly introduced by the Kr ion irradiation. The 3 MeV Kr ion principally losses its energy in the CdZnTe detector due to nuclear collisions and therefore creates more damage than the 2.08 Kr ion irradiation.