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Large-Area, Transparent, and Flexible Infrared Photodetector Fabricated Using P‑N Junctions Formed by N‑Doping Chemical Vapor Deposition Grown Graphene
journal contribution
posted on 2014-07-09, 00:00 authored by Nan Liu, He Tian, Gregor Schwartz, Jeffrey B.-H. Tok, Tian-Ling Ren, Zhenan BaoGraphene
is a highly promising material for high speed, broadband,
and multicolor photodetection. Because of its lack of bandgap, individually
gated P- and N-regions are needed to fabricate photodetectors. Here
we report a technique for making a large-area photodetector on the
basis of controllable fabrication of graphene P-N junctions. Our selectively
doped chemical vapor deposition (CVD) graphene photodetector showed
a ∼5% modulation of conductance under global IR irradiation.
By comparing devices of various geometries, we identify that both
the homogeneous and the P-N junction regions contribute competitively
to the photoresponse. Furthermore, we demonstrate that our two-terminal
graphene photodetector can be fabricated on both transparent and flexible
substrates without the need for complex fabrication processes used
in electrically gated three-terminal devices. This represents the
first demonstration of a fully transparent and flexible graphene-based
IR photodetector that exhibits both good photoresponsivity and high
bending capability. This simple approach should facilitate the development
of next generation high-performance IR photodetectors.