X-ray performance of pixilated CdZnTe detectors

The X-ray performance of CdZnTe detectors with 300μm pixels was investigated. 2mm thick CdZnTe from eV Products Inc. was bump bonded to ERD2004 detector modules. Preliminary experiments with an eV Products detector at room temperature and −400V bias gave a FWHM of 1.93keV at 59.9keV and a peak to valley ratio of 14.9. The performance of individual pixels varied significantly across the devices due to the non-uniformities in the CdZnTe. Experiments at the Diamond Light Source were conducted to investigate the spatial non-uniformity of the detector. A monochromatic X-ray beam was used to measure the energy resolution and peak position to quantify the spatial charge collection efficiency of the detector. A collimated X-ray beam was used to scan the detector. The scanning experiment was used to investigate charge sharing and lateral electric fields within the detector.