title: Large-area, transparent, and flexible infrared photodetector fabricated using P-N junctions formed by N-doping chemical vapor deposition grown graphene.
abstract: Graphene 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.
authors.affiliation: Department of Chemical Engineering, Stanford University , Stanford, California 94305, United States.
authors.forename: Nan
authors.initials: N
authors.lastname: Liu
authors.forename: He
authors.initials: H
authors.lastname: Tian
authors.forename: Gregor
authors.initials: G
authors.lastname: Schwartz
authors.forename: Jeffrey B-H
authors.initials: JB
authors.lastname: Tok
authors.forename: Tian-Ling
authors.initials: TL
authors.lastname: Ren
authors.forename: Zhenan
authors.initials: Z
authors.lastname: Bao
mesh_terms: D004553:Electric Conductivity; D004867:Equipment Design; D006108:Graphite / Q000737:chemistry*; D007259:Infrared Rays; D009584:Nitrogen / Q000737:chemistry*; D055095:Optics and Photonics / Q000295:instrumentation*; D013499:Surface Properties
chemical_list: D006108:Graphite; D009584:Nitrogen