Further process of polarization within a pixellated CdZnTe detector under intense x-ray irradiation

It has been observed that pixellated CdZnTe detectors fabricated from crystals experience an extending of space charge region in the polarized state when exposed to a high flux of x-rays and a low flux of x-rays. In this case, in some areas of the CZT detector polarization occurs without high incident flux. Results from these studies reveal that at very high photon flux rates, a space charge region with high density develops and extends, consistent with the accumulation of positive space charge due to the trapping of free-carrier holes created by the x-ray irradiation. The extending of space charge region observed without high x-ray has a direct influence on the irradiation hardness and charge collection efficiency of the devices.