Synergistic crystallization regulation and defect passivation for growth of high-quality perovskite single crystals towards ultrasensitive X-ray detection

Organic-inorganic hybrid perovskite single crystals are the most promising candidates for X-ray detection. However, the growth of high-quality large-size single crystals is still challenging. In this work, a passivator-assisted crystallization method is proposed to grow high-quality MAPbBr 3 single crystals with an area larger than 400 mm 2 . With 4-trifluoromethyl phenylammonium bromide (CF3-PABr) as a passivator, the generated CF3-PA + can be adsorbed on growing crystal surfaces via not only the interaction between -NH 3 + and Br − , but also the coordination between -CF 3 and Pb 2+ . Therefore, the crystal growth rate is significantly reduced and defect formation is effectively suppressed. Compared with the optimized control crystal, the MAPbBr 3 single crystal grown with CF3-PABr shows effectively suppressed ion migration and a 4-fold larger mobility-lifetime product, enabling a record high X-ray sensitivity of 10.88 × 10 4 μC Gy air −1 cm −2 and a low detection limit of 1.3 nGy air s −1 . This work would help in optimizing the growth of solution-based perovskite single crystals and promoting their commercial applications. This report demonstrates a method of synergistic defect passivation and crystallization regulation, which can significantly improve crystal quality and promote X-ray detector performance.