Infrared LED Enhanced Spectroscopic CdZnTe Detector Working under High Fluxes of X-rays

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 $5\times {10}^5$ and $8\times {10}^6$ photons per mm ${}^2$ per second. It was observed that polarization occurs at an X-ray flux higher than $3\times {10}^6$ 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. View Full-Text