Sensitive and Stable Ruddlesden–Popper Perovskite X-ray Detectors via Defect Passivation

Abstract

Low-dimensional halide perovskite X-ray detectors are advantageous because of their high ionic activation energy and good intrinsic stability under external stimulation, such as heat and humid air. Here, the BA 2 MA 9 Pb 10 I 31 quasi-2D perovskite was modified by incorporating 4-aminobenzonitrile (ABN) molecules, and its performance in X-ray detectors was evaluated. The results demonstrate that the addition of ABN effectively enhances the charge transport properties, reduces the charge recombination rate, and suppresses ion migration in the perovskite. The ABN additive improves the X-ray detector's detection capability at low X-ray dose rates, exhibiting higher sensitivity and lower detection limits. Finally, a BA 2 MA 9 Pb 10 I 31 X-ray detector exhibiting a sensitivity of ∼8000 μC Gy air −1 cm −2 , a limit of detection (LoD) of 6.8 nGy air s −1 , and a detection efficiency of 115% was obtained, which is outperforming than that of a commercialized amorphous selenium detector with a sensitivity of 20 μC Gy air −1 cm −2 and a LoD of 5500 nGy air s −1 . Results presented here indicate that passivating the charged defects in perovskite X-ray detectors is crucial for improving their X-ray detection performance.