Photodetector Based on Spontaneously Grown Strongly Coupled MAPbBr3/N-rGO Hybrids Showing an Enhanced Performance.

Recently, metal-halide perovskites have emerged as a candidate for optoelectronic applications such as photodetectors. However, the poor device performance and instability have limited their future commercialization. We herein report the spontaneous growth of perovskite/N-rGO hybrid structures using a facile solution method and their application for photodetectors. In the hybrid structures, perovskites were homogeneously wrapped by N-rGO sheets through strong hydrogen bonding. The strongly coupled N-rGOs facilitate the charge carrier transportation across the perovskite crystals, but also distort the surface lattice of the perovskite creating potential barrier for charge transfer. We optimize the addition of N-rGO in the hybrid structures to balance the interfacial structural distortion and the inter-crystal conductivity. A high-performance photodetection up to 3 × 104 A/W, external quantum efficiency (EQE) exceeding 105 % and detectivity up to 1012 Jones were achieved in the optimal device with the weight ratio between perovskites and N-rGO to be 8:1.5. The underlying mechanism behind the optimal N-rGO addition ratio in the hybrids has also been rationalized via time-resolved spectroscopic studies as a reference for future application.