Cation-π interactions enabled water-stable perovskite X-ray flat mini-panel imager.

Pan, Wanting; He, Yuhong; Li, Weijun; Liu, Lulu; Guo, Keke; Zhang, Jianglei; Wang, Chao; Li, Bao et al. · Nat Commun · 2024

basic_science · Level V

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Abstract

Sensitive and stable perovskite X-ray detectors are attractive in low-dosage medical examinations. The high sensitivity, tunable chemical compositions, electronic dimensions, and low-cost raw materials make perovskites promising next-generation semiconductors. However, their ionic nature brings serious concerns about their chemical and water stability, limiting their applications in well-established technologies like crystal polishing, micro-processing, photolithography, etc. Herein we report a one-dimensional tryptamine lead iodide perovskite, which is stable in water for several months as the strong cation-π interactions between organic cations. The one-dimensional and two-dimensional tryptamine lead iodide perovskite tablets are switchable through thermal-annealing or water-soaking treatments to relax microstrains. The water-stable and microstrain-free one-dimensional perovskite tablets yield a large sensitivity of 2.5 × 10<sup>6</sup> μC Gy<sub>air</sub><sup>-1</sup> cm<sup>-2</sup> with the lowest detectable dose rate of 5 nGy<sub>air</sub> s<sup>-1</sup>. Microelectrode arrays are realized by surface photolithography to construct high-performance X-ray flat mini-panels with good X-ray imaging capability, and a record spatial resolution of 17.2 lp mm<sup>-1</sup> is demonstrated.