Surface Processing of CdTe Detectors Using Hydrogen Bromide-Based Etching Solution

Chemical etching of CdTe crystals using hydrogen bromide (HBr)-based etchant was studied and its effectiveness in detector leakage current, gamma radiation detection performance was compared with that of a conventional Br-methanol (BM) etched detector. It was found that effect of surface leakage in total detector leakage current was lower in the HBr-processed detectors, and they also exhibited better radiation detection performances than that of the conventional BM-etched detectors. A slight variation in surface chemical states was found in these differently processed crystals which could be related to the observed differences in detector properties.