High performance photodetector based on 2D CH₃NH₃PbI₃ perovskite nanosheets

In this work, a high performance vertical-type photodetector based on two-dimensional (2D) CH₃NH₃PbI₃ perovskite nanosheets was fabricated. The low trap density of the perovskite nanosheets and their short carrier diffusion distance result in a significant performance enhancement of the perovskite-based photodetector. The photoresponsivity of this vertical-type photodetector is as high as 36 mA W⁻¹ at visible wavelength, which is much better than traditional perovskite photodetectors (0.34 mA W⁻¹). Compared with traditional planar-type perovskite-based photodetectors, this vertical-type photodetector also shows the advantages of low-voltage operation and large responsivity. These results may pave the way for exploiting high performance perovskite-based photodetectors with an ingenious device design. (paper)