Sensitive and Stable 2D Perovskite Single-Crystal X-ray Detectors Enabled by a Supramolecular Anchor

摘要

Perovskite X-ray detectors have been demonstrated to be sensitive to soft X-rays (80 keV) for potential medical imaging applications. However, developing X-ray detectors that are stable and sensitive to hard X-rays (80 to 120 keV) for practical medical imaging is highly desired. Here, a sensitive 2D fluorophenethylammonium lead iodide ((F-PEA)(2)PbI4) perovskite single-crystal hard-X-ray detector from low-cost solution processes is reported. Dipole interaction of organic ions promotes the ordering of benzene rings as well as the supramolecular electrostatic interaction between electron-deficient F atoms with neighbor benzene rings. Supramolecular interactions serve as a supramolecular anchor to stabilize and tune the electronic properties of single crystals. The 2D (F-PEA)(2)PbI(4)perovskite single crystal exhibits an intrinsic property with record bulk resistivity of 1.36 x 10(12)omega cm, which brings a low device noise for hard X-ray detection. Meanwhile, the ion-migration phenomenon is effectively suppressed, even under the large applied bias of 200 V, by blocking the ion migration paths after anchoring. Consequently, the (F-PEA)(2)PbI(4)single crystal detector yields a sensitivity of 3402 mu C Gy(-1)air cm(-2)to 120 keV(p)hard X-rays with lowest detectable X-ray dose rate of 23 nGy(air)s(-1), outperforming the dominating CsI scintillator of commercial digital radiography systems by acquiring clear X-ray images under much lower dose rate. In addition, the detector shows high operation stability under extremely high-flux X-ray irradiation.