High-performance 110 kVp hard x-ray detector based on all-crystalline-surface passivated perovskite single crystals

Halide perovskite single crystals (SCs) have attracted much attention for their application in high-performance x-ray detectors owing to their desirable properties, including low defect density, high mobility-lifetime product (mu tau), and long carrier diffusion length. However, suppressing the inherent defects in perovskites and overcoming the ion migration primarily caused by these defects remains a challenge. This study proposes a facile process for dipping Cs(0.05)FA(0.9)MA(0.05)PbI(3) SCs synthesized by a solution-based inverse temperature crystallization method into a 2-phenylethylammonium iodide (PEAI) solution to reduce the number of defects, inhibit ion migration, and increase x-ray sensitivity. Compared to conventional spin coating, this simple dipping process forms a two-dimensional PEA(2)PbI(4) layer on all SC surfaces without further treatment, effectively passivating all surfaces of the inherently defective SCs and minimizing ion migration. As a result, the PEAI-treated perovskite SC-based x-ray detector achieves a record x-ray sensitivity of 1.3 x 10(5) mu C Gy(air)(-1) cm(-2) with a bias voltage of 30 V at realistic clinical dose rates of 1-5 mGy s(-1) (peak potential of 110 kVp), which is 6 times more sensitive than an untreated SC-based detector and 3 orders of magnitude more sensitive than a commercial alpha-Se-based detector. Furthermore, the PEAI-treated-perovskite SC-based x-ray detector exhibits a low detection limit (73 nGy s(-1)), improved x-ray response, and clear x-ray images by a scanning method, highlighting the effectiveness of the PEAI dipping approach for fabricating next-generation x-ray detectors.