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.