Preparation of bismuth-based perovskite Cs3Bi2I6Br3 single crystal for X-ray detector application

Cs 3 Bi 2 I 6 Br 3 perovskite is one of the bismuth iodide family compounds. Because it contains no toxic lead, and has high stability in air and humidity, endowing a potential application prospects in photoelectric and radiation detectors. Herein, the Cs 3 Bi 2 I 6 Br 3 single crystal (Φ13 × 65 mm 3 ) with a (001) preferred direction was grown by using the melt method with solvent-synthesized polycrystalline particles, and the thin single wafer with a thickness up to 0.95 mm was obtained. The as-grown single crystal possesses high infrared transmittance of up to 70% in the range from 400 to 4000 cm −1 and an optical band gap of about 2.03 eV estimated from the visible absorption curve. A highly intrinsic resistivity 2.3 × 10 10 Ω·cm and a dielectric constant about 10 were obtained from the electrical performance parameter measurements. The X-ray sensitivity of the X-ray detector is 55.62 µC/Gy air /cm 2 (incident dose rate 0.24 mGy/s), as well as the signal-to-noise ratio, is up to 301. These results indicate Cs 3 Bi 2 I 6 Br 3 single crystals are a potential material for X-ray detection.