Enhanced performance of solution-processed all-inorganic halide perovskite photodetectors by using bulk heterojunction and lateral configuration

•Both enhanced photocurrent and suppressed dark current were combined in one photodetector.•The molar ratio of CsPbBr3:ZnO film was optimized for high-performance lateral photodetector.•The best device performance confirms the optimum morphology of the hybrid active layer.•The dark current was greatly reduced to the order of 10−12 A by using a wide channel length of 50 µm.•A feasible way for high-performance bulk-heterojunction lateral photodetectors is presented. Currently, all-inorganic halide perovskites are widely investigated for their applications in optoelectronics due to their excellent physical and chemical properties. In this paper, solution-processed bulk-heterojunction lateral photodetectors Ag/CsPbBr3:ZnO/Ag were built to enhance device performance, in which the active CsPbBr3 layer were surface-passivated by ZnO nanoparticles (NPs) in an optimized molar ratio. By optimizing the molar ratio of CsPbBr3 to ZnO NPs (i.e. kR=MCsPbBr3/MZnO), the photocurrent from the lateral photodetector was greatly enhanced and, the dark current was suppressed to as low as 10−12 A due to the lateral configuration by employing a 50 µm-width active layer made through an interdigital mask. As a result, the On/Off current ratio of the lateral photodetector Ag/CsPbBr3:ZnO/Ag reaches to more than 103 for an optimum molar ratio kR= 1:1, and it is 300-folds higher than that of the control device Ag/CsPbBr3/Ag, showing a maximum specific detectivity D* of 1.6 × 1011 Jones with a photoresponsivity of 3.8 mA/W under 16 µW/cm2 405 nm illumination at − 5 V. In this way, it provides an efficient method for solution-processed high-performance photodetectors by combining bulk heterojunction and lateral configuration.