Multienergy x-ray detection and imaging enabled by working voltage regulating unipolar carrier collection in perovskite detectors
Yuwei Li, Xin Wang, Yijing Ding, Jingda Zhao, Shilin Liu, Yubing Xu, Qi Cheng, Ziyu Wei, Damian C. Onwudiwe, Byung Seong Bae, Mehmet Ertuğrul, Ying Zhu, Wenbo Ma, Yang Yang, Wei Lei, Xiaobao Xu
Abstract
Multienergy x-ray imaging can provide additional substance information beyond morphology in conventional energy-integration imaging. The predominant approach, single photon counting, sets stringent requirements on low x-ray flux and signal discrimination and prolongs imaging time. Here, we report on the design of unipolar n-i-n perovskite detectors for multienergy x-ray imaging. Systematic characterization validates electrons dominating carrier dynamics in detectors, and the distribution of generated electrons varies as x-ray energy along its penetrating direction, whereas working voltage can manipulate electron drift length, ensuring their selective collection for x-ray energy discrimination. Our multienergy imaging array adopts high-flux x-ray in a normal imaging system and realizes fast 4-energy-bins x-ray images. By introducing the σ( E i )/σ( E j )-related multienergy digital subtraction algorithm, the images successfully distinguish the substance of targets side by side or by stacking, representing a notable advancement over conventional energy-integration imaging technique.