Evaluation of CdZnTe detectors using crystals grown by the modified vertical bridgman technique

The results of our newest depth sensing coplanar grid CdZnTe detectors will be discussed. These detectors, which utilize the third generation coplanar anode design, were fabricated by Baltic Scientific Instruments, Ltd., using crystals acquired from Yinnel Tech, Inc., having dimensions of 1.5 cmtimes1.5 cmtimes0.9 cm and 1.5 cmtimes1.5 cmtimes0.95 cm. Employing various compensation techniques, an energy resolution of about 1.7% FWHM was achieved for 662 keV gamma rays. The mu e tau e for these crystals were measured and were found to be nonsymmetric for opposite electron drift directions. A study of the spectroscopic performance of CdZnTe for reduced temperature was implemented and we observed severely degraded performance for temperatures below -20 degC