Performance of thallium bromide semiconductor detectors produced by repeated Bridgman method

TlBr crystals have been grown by the Repeated Bridgman method from commercial TlBr materials and characterized to be used as radiation detectors. We have shown that the Repeated Bridgman is effective to reduce the concentration of impurities in TlBr. It was observed that detectors fabricated from higher purity crystal exhibit significant improvement in performance compared to those produced from low purity crystals. However, problems still exist in TlBr detectors, due to the low charge carrier collection efficiency, which is probably caused by additional impurities or defects incorporated during crystal growth and detector fabrication processes. (author)