Bilayered Dion-Jacobson Hybrid Perovskite Bulk Single Crystals Constructed with Aromatic Diammonium for Ultraviolet-Visible-Near-Infrared Photodetection

Two-dimensional (2D) Dion-Jacobson (DJ) hy-brid perovskites (HPs) are widely used in the photodetection field due to their high stability and excellent carrier transport performance. However, current photodetectors based on DJ HPs can work only in the ultraviolet and visible wavebands, which limits their application in near-infrared (NIR) photodetection. Herein, for the first time, ultraviolet-visible-NIR photodetection is realized in the bulk single crystal of 2D bilayered DJ HP (3AMPY)(EA)Pb2Br7 (3AMPY = 3-(aminomethyl)pyridinium, EA = ethylamine). Structurally, the introduction of aromatic diammonium makes (3AMPY)(EA)Pb2Br7 have a shorter layer spacing (3.561 angstrom) and a more rigid structure. In addition, benefiting from the strong quantum and dielectric confinements of 2D HPs, (3AMPY)(EA)Pb2Br7 shows an excellent two-photon absorption (TPA) coefficient of up to 61.1 cm/MW under the excitation of an 800 nm femtosecond laser. Notably, (3AMPY)(EA)Pb2Br7 exhibits efficient photodetection from ultraviolet (377 nm) and visible (405 nm) to NIR (800 nm) wavebands, with on/off ratios of current higher than 103.