Enhanced detectivity and response time of perovskite photodetector by modifying PEDOT:PSS with DMSO-flushing
【摘要】：High performance methylammonium lead triiodide(CH_3NH_3PbI_3) perovskite photodetectors have been fabricated by introducing highly conductive Poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate)(PEDOT:PSS) layers modified by dimethyl sulfoxide(DMSO)-flushing, which significantly improve the light harvesting, charge carrier transport and extraction. Both scanning electron microscopy(SEM) imaging and X-ray analysis reveal that the perovskite thin films grown on PEDOT:PSS layers modified by DMSO-flushing exhibit higher crystallinity and closer packing of CH_3NH_3PbI_3 perovskite film on modified PEDOT: PSS layer,which account for more efficient pathways with lower resistance for charge carrier transport. Comparing to the standard perovskite photodetectors(PPDs) based on pristine PEDOT:PSS HTL, the modified PPDs exhibit much superior conductivity and sensibility. Based on the optimized photodetector, we constructed a high detectivity and fast response photodetector with detectivity value reaching 5.37×10~(12) Jones at a low working voltage of -0.1 V and response time reaching 258 ns.The optimization of the PEDOT:PSS layer provides a promising way to fabricate high-performance perovskite-based optoelectronic devices.