Electrical and γ-ray energy spectrum response properties of PbI2 crystal grown by physical vapor transport

Lead iodide single crystal was grown by physical vapor transport method. Two radiation detectors with different configurations were fabricated from the as-grown crystal. The electrical and γ-ray response properties at room temperature of the both detectors were investigated. It is found that the dark resistivity of the detectors are respectively 3 × 1010 Ω·cm for bias electric field parallel to crystal c-axis (E//c) and 2 × 108 Ω·cm for perpendicular to crystal c-axis (E⊥c). The energy spectrum response measurement shows that both detectors were sensitive to 241Am 59.5 keV γ-rays, and achieved a good energy resolution of 16.8% for the E ⊥ c-axis configuration detector with a full width at half maximum of 9.996 keV.