title: Hot Electron-Based Near-Infrared Photodetection Using Bilayer MoS2.
abstract: Recently, there has been much interest in the extraction of hot electrons generated from surface plasmon decay, as this process can be used to achieve additional bandwidth for both photodetectors and photovoltaics. Hot electrons are typically injected into semiconductors over a Schottky barrier between the metal and semiconductor, enabling generation of photocurrent with below bandgap photon illumination. As a two-dimensional semiconductor single and few layer molybdenum disulfide (MoS2) has been demonstrated to exhibit internal photogain and therefore becomes an attractive hot electron acceptor. Here, we investigate hot electron-based photodetection in a device consisting of bilayer MoS2 integrated with a plasmonic antenna array. We demonstrate sub-bandgap photocurrent originating from the injection of hot electrons into MoS2 as well as photoamplification that yields a photogain of 10(5). The large photogain results in a photoresponsivity of 5.2 A/W at 1070 nm, which is far above similar silicon-based hot electron photodetectors in which no photoamplification is present. This technique is expected to have potential use in future ultracompact near-infrared photodetection and optical memory devices.
authors.affiliation: Department of Electrical Engineering and Computer Science and ∥Department of Mechanical Engineering, Vanderbilt University , Nashville, Tennessee 37212, United States.|Department of Physics and Astronomy and §Interdisciplinary Graduate Program in Materials Science, Vanderbilt University , Nashville, Tennessee 37235, United States.
authors.forename: Wenyi
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Electrical Engineering and Computer Science and ∥Department of Mechanical Engineering, Vanderbilt University , Nashville, Tennessee 37212, United States.|Department of Physics and Astronomy and §Interdisciplinary Graduate Program in Materials Science, Vanderbilt University , Nashville, Tennessee 37235, United States.
authors.forename: Andrey
authors.initials: A
authors.lastname: Klots
authors.affiliation: Department of Electrical Engineering and Computer Science and ∥Department of Mechanical Engineering, Vanderbilt University , Nashville, Tennessee 37212, United States.|Department of Physics and Astronomy and §Interdisciplinary Graduate Program in Materials Science, Vanderbilt University , Nashville, Tennessee 37235, United States.
authors.forename: Dhiraj
authors.initials: D
authors.lastname: Prasai
authors.affiliation: Department of Electrical Engineering and Computer Science and ∥Department of Mechanical Engineering, Vanderbilt University , Nashville, Tennessee 37212, United States.|Department of Physics and Astronomy and §Interdisciplinary Graduate Program in Materials Science, Vanderbilt University , Nashville, Tennessee 37235, United States.
authors.forename: Yuanmu
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Electrical Engineering and Computer Science and ∥Department of Mechanical Engineering, Vanderbilt University , Nashville, Tennessee 37212, United States.|Department of Physics and Astronomy and §Interdisciplinary Graduate Program in Materials Science, Vanderbilt University , Nashville, Tennessee 37235, United States.
authors.forename: Kirill I
authors.initials: KI
authors.lastname: Bolotin
authors.affiliation: Department of Electrical Engineering and Computer Science and ∥Department of Mechanical Engineering, Vanderbilt University , Nashville, Tennessee 37212, United States.|Department of Physics and Astronomy and §Interdisciplinary Graduate Program in Materials Science, Vanderbilt University , Nashville, Tennessee 37235, United States.
authors.forename: Jason
authors.initials: J
authors.lastname: Valentine
keywords: Plasmon resonance; bilayer MoS2; hot electron injection; near-infrared photodetection