Metal-Free PAZE-NH 4 X 3 ⋅H 2 O Perovskite for Flexible Transparent X-ray Detection and Imaging.

Metal-free perovskites are of interest for their chemical diversity and eco-friendly properties, and recently have been used for X-ray detection with superior carrier behavior. However, the size and shape complexity of the organic components results in difficulties in evaluating their stability in high-energy radiation. Herein, we introduce multiple hydrogen-bond metal-free PAZE-NH 4 X 3 ⋅H 2 O perovskite, where H 2 O leads to more hydrogen bonds appearing between organic molecules and the perovskite host. As suggested by the theoretical calculations, multiple hydrogen bonds promote stiffness of the lattice, and increase the diffusion barrier to inhibit ionic migration. Then, low trap density, high μτ products and structural flexibility of PAZE-NH 4 Br 3 ⋅H 2 O give a flexible X-ray detector with the highest sensitivity of 3708 μC Gy air -1  cm -2 , ultra-low detection limit of 0.19 μGy air -1  s -1 and superior spatial resolution of 5.0 lp mm -1 .