Incorporating an Aromatic Diammonium To Assemble Bilayered Dion-Jacobson Perovskite Crystals for Weak Light Detection.

Two-dimensional (2D) Dion-Jacobson (DJ) hybrid perovskites with exceptional stability and enhanced out-of-plane carrier transport are regarded as one of the competive candidates for constructing next-generation photodetectors. However, the studies of DJ hybrid perovskites on weak light detection remain scarce, and the devices based on them usually show relatively poor weak light detection ability, with a detection limit of around μW/cm 2 . Herein, a new DJ hybrid perovskite (3AMPY)(MA)Pb 2 Br 7 [3AMPY is 3-(aminomethyl)pyridinium, and MA is methylammonium] with short interlayer spacing and more lattice rigidity is obtained. The devices based on (3AMPY)(MA)Pb 2 Br 7 crystals exhibit an ultrahigh sensibility to weak light at 377 and 405 nm, with an extremely low detection limit of ∼70 nW/cm 2 . Moreover, the on/off ratios and detectivity of the devices can reach ∼10 3 and ∼10 12 Jones at both 377 and 405 nm, respectively. This work highlights great potential of DJ hybrid perovskites toward weak light detection.