Effects of Deep-Level Defects on the Current Distortion of CZT γ -Ray Detector Under Temporal Response

Under high flux rate
$\gamma $
-ray, the relationships between the current distortion and the specific defect levels in the CdZnTe (CZT) detector are analyzed. Sentaurus Technology Computer Aided Design (TCAD) software, the Pockels effect test system, and
$\gamma $
-ray radiation instrument are operated in this study. The theoretical and experimental results show that the sharp peak and the flat current nonlinearity of the temporal response for the CZT detector under
$\gamma $
-ray radiation are mainly contributed by the trapping and detrapping effects of a deep-level defect on
$\gamma $
-ray-generated carriers. The electric field intensity distribution in CZT crystal follows linearity with the distance from the cathode with and without the
$\gamma $
-ray flux rate of
$1.33\times 10^{8}$
MeV
$\cdot $
cm
$^{-2}\cdot $
s1. The improvement effect of infra-red (IR) illumination on the current distortion is the increase of the effective ionized density for the deep-level defect and the trapping probability for electrons, leading to the suppression of the sharp peak phenomenon. These results can help us better understand the current distortion of the CZT detector under high flux rate radiation, which can provide significant theoretical support for further research on distortion suppression and performance optimization.