Multienergy x-ray detection and imaging enabled by working voltage regulating unipolar carrier collection in perovskite detectors

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.