UV–Vis photodetector based on ionic liquid-modified perovskite–ZnO composite

Photodetectors (PDs) that combine inorganic semiconductors with organic lead halide perovskites to produce broader spectral responses have captured great interest from researchers; however, the imperfect perovskite crystallinity and the defects on the film surface are still the main factors inhibiting the PD's capability. Here, we proposed a simple method by introducing ionic liquid [1-butyl-3-methylimidazolium iodide (BMII)] into ZnO/CH 3 NH 3 PbI 3 to encourage the growth of perovskite grains, raise the crystallinity of perovskite, and reduce the trap states, finally enhancing the photoelectric performances. After the addition of BMII, there are 171-fold, 74-fold, and 76-fold increases, respectively, in the light–dark current ratio, the spectral responsivity, and the external quantum efficiency, meanwhile, detectivity can reach 2.58 × 10 13  Jones in the UV–vis range. The impressive results can be owed to the higher carrier concentration of ZnO/CH 3 NH 3 PbI 3 with BMII, which can facilitate the charge transfer and suppress the recombination of photogenerated carriers. This study may be of assistance to extend our knowledge of developing high-performance PDs.