• 文献标题:   Bandwidth Enhancement of Graphene-Organic Hybrid Photoconductors by Accelerating Electron Transfer Processes at Graphene Interface
  • 文献类型:   Article
  • 作  者:   LEE Y, CHA S, KIM C
  • 作者关键词:   bandwidth enhancement, donoracceptor system, electron transfer, grapheneorganic photoconductor, molecular doping
  • 出版物名称:   ADVANCED MATERIALS INTERFACES
  • ISSN:   2196-7350
  • 通讯作者地址:  
  • 被引频次:   1
  • DOI:   10.1002/admi.202100478 EA JUL 2021
  • 出版年:   2021

▎ 摘  要

Photodetectors based on a heterojunction between graphene and photoactive layers have attractive features such as high responsivity and spectral sensitivity, but their narrow bandwidth originating from charge trapping is a major drawback. Here, it is demonstrated that the bandwidth of a graphene-organic hybrid photoconductor, where a planar bilayer of fullerene (C-60) and zinc phthalocyanine (ZnPc) is in contact with the graphene layer, can be significantly increased by doping the C-60 layer with ZnPc. The bandwidth, which increases with the doping concentration, is found to be more than two orders of magnitude higher at 40 vol% doping than that of the undoped device. Consequently, the 40%-doped device has a fall time of the photocurrent transient of 19 mu s, which is approximate to 300 times smaller than that of the undoped device (5.8 ms). Based on the model developed to analyze the electron transfer processes between the graphene and C-60 layers, the increased bandwidth is attributed to the reduced electron lifetime in the C-60 trap state by recombination with holes photogenerated in the ZnPc domains in the C-60 layer.