Solution‐Grown Hypervalent CsI3 Crystal for High‐Sensitive X‐Ray Detection

• Published in: physica status solidi (b) 2020-01, Vol.257 (1), p.n/a
• Main Authors: Zhang, Bin-Bin, Liu, Xin, Xiao, Bao, Gao, Kaige, Dong, Song-Tao, Xu, Yadong, He, Yucong, Zhou, Jian, Jie, Wanqi
• Format: Article
• Language: English
• Subjects: carrier transport behavior; crystal growth; CsI3; X-ray detection
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/pssb.201900290

Herein, a novel binary compound hypervalent CsI3 crystal is designed for X‐ray detection. Solution‐grown rod‐like CsI3 single crystal is identified as a semiconductor with a bandgap of 1.79 eV and high resistivity of 2.17 × 109 Ω cm, which make it suitable for X‐ray detection. Based on carbon/CsI3 crystal/carbon device, a high X‐ray sensitivity of up to 158.1 ± 6.0 μC Gy−1 cm−2 is achieved under a low electrical field of 55 V mm−1, which is eight times higher than that of the commercial α‐Se X‐ray detectors. The high sensitivity of hypervalent CsI3 is attributed to the long carrier life time (≈470 μs) and large photocurrent gain (150%). The potential applications of photoconversion and nuclear radiation detection using alkali halides are demonstrated. Solution‐grown hypervalent CsI3 single crystal is a semiconductor with a proper bandgap of 1.79 eV, high resistivity of 3.2 × 109 Ω cm, and high X‐ray detection sensitivity of 158.1 ± 6.0 μC Gy−1 cm−2 under 55 V mm−1, which can be applied for the direct X‐ray photon conversion at room temperature.