Synergistic 1D/3D perovskite and Schottky junction for high-performance X-ray flat panel imaging

Organic-inorganic hybrid perovskites have emerged as promising materials for the next-generation X-ray flat panel imagers, but the thorny problems of large dark current and baseline drift have hindered their development. Here we judiciously combine a 1D-CsPbI 3 /3D-FAPbI 3 perovskite and a Schottky junction in the design of a novel perovskite X-ray detector to boost the imaging performance. The n-type 3D-FAPbI 3 forms a high Schottky barrier with the carbon electrode to suppress the dark current and launch electron tunneling under X-ray on, while the 1D-CsPbI 3 layer further minimizes dark current and baseline drift by inhibiting hole injection and ion migration. Consequently achieved are an enhanced sensitivity of 19,264 μC Gy air −1  cm −2 , a low LoD of 38.4 nGy air s −1 , a radically lowered baseline drift of 4.21 × 10 −6  nA cm −1  V −1  s −1 and a drastic dark current reduction by two orders of magnitude at 150 V mm −1 . The perovskite flat-panel detector (PeFPD) achieves a high resolution of 0.54 lp pix −1 (4.29 lp mm −1 ) over a large area of 3.2 × 3.2 cm 2 , capable of capturing intricate internal structures of both biological specimens and industrial products. This work highlights the design of junctions in advancing the perovskite-based direct conversion flat-panel X-ray imaging systems.