Ultralow-dose X-ray imaging enabled by vertically homogeneous perovskite films
Zhiqiang Liu, Jincong Pang, Ziling Zhou, Hao Chen, Qinghao Ling, Chenxing Li, Yuanpeng Shi, Zhuangzhuang Yang, Ling Xu, Zhiping Zheng, Zhen Li, Jiang Tang, Xiaoping Ouyang, Guangda NiuAbstract
Artificial intelligence (AI) is rapidly pushing imaging and sensing toward automated, quantitative decision-making, heightening the demand for reliable low-photon-flux detection and imaging across infrared through X-ray regimes, yet developing detectors that truly operate effectively at ultralow photon fluxes has been a challenge. As a canonical instance, low-dose X-ray imaging operates under intrinsically sparse photon statistics, where Poisson fluctuations along the absorption depth couple to vertical transport non-uniformity and are statistically amplified at ultralow dose. Here we elucidate this materials-to-electronics bottleneck and develop a new liquid-phase growth and annealing (LPGA) strategy that eliminates thermal and mass-transport instabilities in conventional methods during crystallization, yielding perovskite films with exceptional vertical uniformity. This enables depth-independent charge collection, significantly reducing stochastic fluctuations in the readout and achieving a ten-fold reduction in image noise. In imaging applications, our detectors deliver high-quality X-ray imaging at an ultralow effective per-pixel integration dose of 40.6 nGyair, setting a new benchmark for safe, high-quality clinical imaging.