CdZnTe photon-counting detection module for multi-energy X-ray imaging

Three Cadmium Zinc Telluride (CZT) photon-counting detection modules with 1 × 16 pixels were fabricated using CZT wafers of different crystalline qualities. The thermally stimulated current (TSC) spectrum method was used to characterize wafer quality from which modules were fabricated. The wafers show different levels, corresponding to different crystalline defects, indicated by the traps appearing in the TSC spectrum. The first trap is believed to occur because of Indium doping. Others are thought to be caused by crystalline defects. By comparing the pixel counts of the three modules with TSC results, we show that the first trap contributes a positive effect to detector performance, whereas others contribute negative effects. The assembled module board comprising the best sample produces high-quality X-ray images.