All‐Perovskite Integrated X‐Ray Detector with Ultrahigh Sensitivity

Abstract Recently, halide perovskites represent potential materials in X‐ray detection via both direct and indirect ways. Generally, thick active materials are necessary to completely absorb X‐ray photons while inefficient carrier collection leads to low device sensitivity. Besides, though perovskite nanocrystal (NC) scintillators can be used with silicon detectors, they suffer from strong reabsorption problem and the responsivity of silicon detectors is usually low. Herein, an effective strategy based on all‐perovskite integrated device is demonstrated to greatly improve the sensitivity of X‐ray detector. On one hand, efficient ultrafast exciton routing within CsPbBr 3 NCs induces a large Stokes shift, and then greatly improved photoluminescence quantum yield (> 50%) and radioluminescence efficiency (> 3‐fold) are achieved. On the other hand, perovskite photodiode (PD) with responsivity higher than 0.4 A W −1 in a wide band is fabricated. The integrated detector takes full advantages of high X‐ray to emission efficiency of engineered CsPbBr 3 NCs and high responsivity of perovskite PDs, respectively, and a record high sensitivity of 54684 µC Gy −1 cm −2 at the dose rate of 8.8 µGy s −1 is achieved. This work undoubtedly opens another window for perovskite X‐ray detectors with better performances or even higher spatial resolution.