2D Hybrid Perovskite Incorporating Cage-Confined Secondary Ammonium Cation toward Effective Photodetection

By confining the secondary dimethylammonium (DMA) cation in the distorted perovskite cavity, we assembled a new 2D Ruddlesden-Popper metal halide perovskite of (i-BA)2(DMA)Pb2Br7 (i-BA = n-isobutylammonium), in which DMA cation templates its inorganic perovskite frameworks and its quantum-well motif renders fascinating photoresponse. Crystal-based planar arrays exhibit effective photodetection behaviors, including notable detectivity (~5.6×10^12 Jones), high responsivity (~1.25 A W-1) and large switching ratio (~ 1.5×10^3). Such properties result from its low dark current restricted to the hopping barrier of insulated organic bilayer and strong in-plane photoresponse correlated with the perovskite network. This work throws light on the targeted exploration of photosensitive candidates in the family of organic-inorganic hybrid perovskites, as well as high-performance devices.