Characterization of PbI2 radiation detectors using the response of α-rays

An improved method is proposed for the production of single crystals of lead iodide (PbI₂). For the work reported here a modified Bridgman method is used. Bulk-type nuclear radiation detectors have been fabricated by use of crystals grown by this method. The characteristics of the detectors, particularly the response for 5.48 MeV α-particles from ²⁴¹Am source, have been measured and compared with characteristics of other detectors fabricated with crystals grown by the ordinary Bridgman method. An α-peak has been clearly observed in the pulse-height spectrum. On the other hand, no peak has been observed in the detectors made from crystals grown by the ordinary Bridgman method. From the relations of peak position versus applied bias voltage, the average energy to produce electron-hole pairs and the μτ product of holes are estimated to be about 30 eV and 10^-7 cm²/V, respectively