title: High-responsivity graphene/InAs nanowire heterojunction near-infrared photodetectors with distinct photocurrent on/off ratios.
abstract: Graphene is a promising candidate material for high-speed and ultra-broadband photodetectors. However, graphene-based photodetectors suffer from low photoreponsivity and I(light)/I(dark) ratios due to their negligible-gap nature and small optical absorption. Here, a new type of graphene/InAs nanowire (NW) vertically stacked heterojunction infrared photodetector is reported, with a large photoresponsivity of 0.5 AW(-1) and I(light)/I(dark) ratio of 5 × 10(2), while the photoresponsivity and I(light)/I(dark) ratio of graphene infrared photodetectors are 0.1 mAW(-1) and 1, respectively. The Fermi level (E(F)) of graphene can be widely tuned by the gate voltage owing to its 2D nature. As a result, the back-gated bias can modulate the Schottky barrier (SB) height at the interface between graphene and InAs NWs. Simulations further demonstrate the rectification behavior of graphene/InAs NW heterojunctions and the tunable SB controls charge transport across the vertically stacked heterostructure. The results address key challenges for graphene-based infrared detectors, and are promising for the development of graphene electronic and optoelectronic applications.
authors.affiliation: National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, 500 Yutian Road, Shanghai, 200083, China; Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China.
authors.forename: Jinshui
authors.initials: J
authors.lastname: Miao
authors.forename: Weida
authors.initials: W
authors.lastname: Hu
authors.forename: Nan
authors.initials: N
authors.lastname: Guo
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Lu
authors.forename: Xingqiang
authors.initials: X
authors.lastname: Liu
authors.forename: Lei
authors.initials: L
authors.lastname: Liao
authors.forename: Pingping
authors.initials: P
authors.lastname: Chen
authors.forename: Tao
authors.initials: T
authors.lastname: Jiang
authors.forename: Shiwei
authors.initials: S
authors.lastname: Wu
authors.forename: Johnny C
authors.initials: JC
authors.lastname: Ho
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.forename: Xiaoshuang
authors.initials: X
authors.lastname: Chen
authors.forename: Wei
authors.initials: W
authors.lastname: Lu
keywords: InAs nanowires; graphene; heterojunctions; infrared; photodetectors