Electrical properties of x-ray detector based on bismuth tri-iodide single crystal with electrode configuration considering

Bismuth tri-iodide (BiI3) single crystals for x-ray detectors application were grown by using physical vapor transport method. Detectors with different electrode configuration were fabricated for electrical and x-ray detection performance measurements. Electrical anisotropy including resistivity, dark current, carrier transport and x-ray induced photoelectricity properties was obtained. Carrier scattering effect deriving from lattice structure, combination bond, dislocation and stacking fault is responsible for the anisotropy properties. Dark current of the detectors with electrical field parallel (E//c) and perpendicular (E ⊥ c) to crystal c-axis were obtained as 0.5 pA and 2.1 pA, respectively. A remarkable signal-to-noise ratio of 896.4 and the sensitivity up to 0.526 × 104 μC Gy−1 cm−2 are achieved in E ⊥ c-axis configuration under 0.02 V μm−1 DC electric field and x-ray exposure dosage rate of 489.78 μGy h−1.