Solution-processed photodetectors based on organic-inorganic hybrid perovskite and nanocrystalline graphite

We present here solution-processed photodetectors based on a methyl ammonium lead iodide perovskite (MAPbI₃) and nanocrystalline graphite (NCG) hybrid composite. The highest responsivity of the best MAPbI₃/NCG photodetector was 795 mA W^-1 at 500 nm visible light, which is almost twice as high as that of the NCG-free MAPbI₃ photodetector (408 mA W^-1). The enhanced performance of the MAPbI₃/NCG photodetector arises from the improved charge extraction at the MAPbI₃/NCG interface. The dependence of photodetector performance on the mass percentage of NCG (the ratio of NCG to MAPbI₃) in the hybrid materials is also reported here, and is correlated to the fabrication process. Moreover, by comparing the responsivity of the devices with different channel lengths, we show that the performance of hybrid photodetectors can be further tuned by tailoring the channel length.