Green solvent blade-coated MA3Bi2I9 for direct-conversion X-ray detectors

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Materials for optical and electronic devices, 2022-03, Vol.10 (16), p.6236-6242
• Main Authors: Dong, Siyin, Deyu Xin, Zhang, Min, Tie, Shujie, Cai, Bing, Ma, Qingshan, Zheng, Xiaojia
• Format: Article
• Language: English
• Subjects: Bismuth; Lead free; Matter & antimatter; Nondestructive testing; Optoelectronics; Perovskites; Product testing; Sensitivity; Sensors; Solvents; Toxicity; X ray detectors
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/d2tc00522k

Direct X-ray detectors, which can convert an X-ray signal into electrical current with superior sensitivity, are of great interest for a wide range of applications, including medical diagnostics, security screening, and nondestructive product testing. Halide perovskites are a recently demonstrated new X-ray detection candidate due to their excellent optoelectronic characteristics and robust fabrication. However, toxicity issues from both the materials and processing process, and lack of high quality large-area halide perovskite films for stable X-ray detectors are obvious obstacles to their practical application. Here, we explored green methylammonium acetate (MAAc) solvent blade-coated lead-free methylammonium bismuth iodide (MA3Bi2I9) films for direct-conversion X-ray detectors. Methylamine chloride (MACl) was used as an additive to improve the quality of the MA3Bi2I9 films, resulting in X-ray detectors with a sensitivity of 100.16 μC Gyair−1 cm−2, and a low limit of detection of 98.4 nGyair s−1. This research provides a green method for preparing perovskite X-ray detectors.