Solution Processed Trilayer Structure for High-Performance Perovskite Photodetector

Due to their outstanding performance, low cost, ease of fabrication, diverse photonic, and optoelectronic applications, metal halides perovskite have attracted extensive interest in photodetector applications. Currently, devices made by metal oxides, metal sulfides, and 2D materials had achieved good responsivity, but suffered from high dark current, slow response speed, small on-off ratio, and poor stability. Whole performances of these photodetectors are not satisfactory. Here, a lateral perovskite (CH3NH3PbBr3)/Ethanolamine/TiO2 (in ethanol) trilayer photodetector is designed for achieving high performance. EA treatment enhances electron extraction and reduces undesired recombination. This trilayer device shows good performances with low dark current of 1.5 × 10−11 A, high on-off ratio of 2700, high photodetectivity of 1.51 × 1012 Jones, high responsivity of 0.13 A W−1, and high stability, comparative to conventional single layer devices. This work provides the way to improve the performance of metal halide perovskite photodetectors.