Abstrakt
This paper describes an application of infrared light-induced de-polarization applied on a polarized CdZnTe detector working under high radiation fluxes. We newly demonstrate the influence of a high flux of X-rays and simultaneous 1200-nm LED illumination on the spectroscopic properties of a CdZnTe detector.
CdZnTe detectors operating under high radiation fluxes usually suffer from the polarization effect, which occurs due to a screening of the internal electric field by a positive space charge caused by photogenerated holes trapped at a deep level. Polarization results in the degradation of detector charge collection efficiency.
We studied the spectroscopic behavior of CdZnTe under various X-ray fluxes ranging between 5 x 10(5) and 8 x 10(6) photons per mm(2) per second. It was observed that polarization occurs at an X-ray flux higher than 3 x 10(6) mm(-2) . s(-1).
Using simultaneous illumination of the detector by a de-polarizing LED at 1200 nm, it was possible to recover X-ray spectra originally deformed by the polarization effect.