Fabrication and testing of antimony doped bismuth tri-iodide semiconductor gamma-ray detectors

• Antimony (Sb) doped BiI3 crystals were grown by the modified vertical Bridgman technique.
• Effect of surface treatment on BiI3 radiation detectors was investigated.
• Radiation response was measured by recording gamma-ray spectra at room temperature.
• Maiden response of BiI3 to gamma-rays was reported.
• Electron mobility-lifetime product was estimated.

Antimony (Sb) doped bismuth tri-iodide (BiI3) radiation detectors were fabricated from large single crystals that were grown using the modified vertical Bridgman technique. Detectors were prepared by subjecting the crystal surfaces to different mechanical and chemical treatments. Surface quality of the detectors was evaluated using optical microscopy. The influence of surface quality on detector performance was analyzed by measuring the leakage current for each of the detectors. The radiation response of the detectors was measured using an Americium (241Am) gamma-ray source at room temperature. The first successful use of BiI3 detectors for gamma-ray spectroscopy is reported here with energy resolution of 7.5% at 59.5 keV. The mobility-lifetime product for electrons was also estimated to be about 5.2 ×× 10−4 cm2/V.