Cage-incorporation of secondary amine in Ruddlesden-Popper 2D hybrid perovskite with strong photoconductivity and polarization response

Two-dimensional (2D) RuddLesden-Popper hybrid perovskites (RPHPs) have shown enormous potentiaL for photoelectric applications owing to their advantages of structural diversity and unique physical properties. Despite extensive studies, the cage-incorporation of secondary amines (e.g., dimethylamine, DMA) to explore 2D RPHP5 remains a great challenge. Herein, we present a new member of 2D RPHP5, (BA)(2) (DMA)Pb2Br7 (1, BA(+) = n-butyLammonium), for which organic DMA(+) cations are enclosed in perovskite cavities. The inorganic perovskite sheets and organic BA(+) spacing Layers are arranged in the alternate packings, resembling a 2D quantum-well motif. This feature is advantageous for the photoconductivity properties. Consequently, the crystal-based array detectors of 1 exhibit strong photodetection performances, including high detectivity (2.0 x 10(11) Jones), Large responsivity (31.1 mA W-1), and fast response time (similar to 8 mu s). Moreover, its intrinsic 2D quantum-well structure endows significant anisotropy of conductivity and optical absorption, which account for the strong polarization response with a Large dichroic ratio of similar to 1.43, falling in the range of other 2D RPHP5. These results reveal the potentiaL of 1 for photodetection and simultaneously shed Light on the research on new candidates of 2D RPHP5.