Research on New Method for Growing Lead Iodide (PbI_2) Single Crystal

An analysis for the growth process of PbI2 single crystal by bridgman method has been made.It is found that during the growth process,the iodine vaporizing and condensing,the lead segregating and precipitating are two important factors affecting the crystal quality with ampoule descending.A new pull method using U-type ampoule was proposed in the paper to grow PbI2 single crystal,the results show the iodine evaporating was effectively avoided and the segregating lead removed,and an orange and translucent PbI2 crystal was obtained.Tests demonstrated that the crystallinity of the grown PbI2 crystal is excellent,the infrared transmission is about 45% and the resistivity is about 1.7×1012Ω·cm.All of these are the base for fabrication of PbI2 room temperature nuclear radiation detectors with excellent performance.