Characterization of the PbI/sub 2/ crystal as a material for radiation detectors

We have been studying a radiation detector which uses lead iodide crystal. The growth of PbI/sub 2/ crystal used two kinds of method. One is the zone melting method and the other is the vapor phase epitaxy method. The performance of the detector fabricated from a crystal grown by the former method showed better characteristics than the detector fabricated from the crystal grown by the latter. Results of XPS and photoluminesence measurement, suggest that the behavior of the iodine atoms in the crystal influenced and controlled the performance of the detector.