title: Single InAs nanowire room-temperature near-infrared photodetectors.
abstract: Here we report InAs nanowire (NW) near-infrared photodetectors having a detection wavelength up to ∼1.5 μm. The single InAs NW photodetectors displayed minimum hysteresis with a high Ion/Ioff ratio of 10(5). At room temperature, the Schottky-Ohmic contacted photodetectors had an external photoresponsivity of ∼5.3 × 10(3) AW(-1), which is ∼300% larger than that of Ohmic-Ohmic contacted detectors (∼1.9 × 10(3) AW(-1)). A large enhancement in photoresponsivity (∼300%) had also been achieved in metal Au-cluster-decorated InAs NW photodetectors due to the formation of Schottky junctions at the InAs/Au cluster contacts. The photocurrent decreased when the photodetectors were exposed to ambient atmosphere because of the high surface electron concentration and rich surface defect states in InAs NWs. A theoretical model based on charge transfer and energy band change is proposed to explain this observed performance. To suppress the negative effects of surface defect states and atmospheric molecules, new InAs NW photodetectors with a half-wrapped top-gate had been fabricated by using 10 nm HfO2 as the top-gate dielectric.
authors.affiliation: National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences , 500 Yutian Road, Shanghai 200083, 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: Xuming
authors.initials: X
authors.lastname: Zou
authors.forename: Lei
authors.initials: L
authors.lastname: Liao
authors.forename: Suixing
authors.initials: S
authors.lastname: Shi
authors.forename: Pingping
authors.initials: P
authors.lastname: Chen
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Fan
authors.forename: Johnny C
authors.initials: JC
authors.lastname: Ho
authors.forename: Tian-Xin
authors.initials: TX
authors.lastname: Li
authors.forename: Xiao Shuang
authors.initials: XS
authors.lastname: Chen
authors.forename: Wei
authors.initials: W
authors.lastname: Lu