Growth and characterization of a PbI2 single crystal used for gamma ray detectors

Lead iodide (PbI₂) is an important material for room temperature radiation detectors. In this paper, we have grown PbI₂ single crystal through a special craft, from which γ‐ray detector has also been fabricated. X‐ray diffraction analysis indicates structure of the grown crystal is 2H with hexagonal space group P3m1. Infrared transmission measurement shows transmission rate of the grown crystal sample (10×10×1mm³) reaches 40% averagely in range of 400～4000cm^‐1. Ultraviolet absorbing test indicates cut‐off wavelength of the sample is 547.6nm, corresponding band gap of 2.27eV. Room temperature detector fabricated from the grown crystal is sensitive to ²⁴¹Am 59.5KeV γ‐ray. Full width at half maximum (FWHM) of the obtained energy spectrum is 26.7KeV. All the results indicate the PbI₂ crystal grown through the special craft is of good characteristics and can be used for γ‐ray detector. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)