title: Extrinsic Origin of Persistent Photoconductivity in Monolayer MoS2 Field Effect Transistors.
abstract: Recent discoveries of the photoresponse of molybdenum disulfide (MoS2) have shown the considerable potential of these two-dimensional transition metal dichalcogenides for optoelectronic applications. Among the various types of photoresponses of MoS2, persistent photoconductivity (PPC) at different levels has been reported. However, a detailed study of the PPC effect and its mechanism in MoS2 is still not available, despite the importance of this effect on the photoresponse of the material. Here, we present a systematic study of the PPC effect in monolayer MoS2 and conclude that the effect can be attributed to random localized potential fluctuations in the devices. Notably, the potential fluctuations originate from extrinsic sources based on the substrate effect of the PPC. Moreover, we point out a correlation between the PPC effect in MoS2 and the percolation transport behavior of MoS2. We demonstrate a unique and efficient means of controlling the PPC effect in monolayer MoS2, which may offer novel functionalities for MoS2-based optoelectronic applications in the future.
authors.affiliation: Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan.
authors.forename: Yueh-Chun
authors.initials: YC
authors.lastname: Wu
authors.affiliation: 1] Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan [2] Department of Physics, National Taiwan University, Taipei 106, Taiwan.
authors.forename: Cheng-Hua
authors.initials: CH
authors.lastname: Liu
authors.affiliation: Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan.
authors.forename: Shao-Yu
authors.initials: SY
authors.lastname: Chen
authors.affiliation: 1] Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan [2] Department of Physics, National Taiwan University, Taipei 106, Taiwan.
authors.forename: Fu-Yu
authors.initials: FY
authors.lastname: Shih
authors.affiliation: Department of Materials Science and Engineering, National Taiwan University, Taipei 106, Taiwan.
authors.forename: Po-Hsun
authors.initials: PH
authors.lastname: Ho
authors.affiliation: Department of Materials Science and Engineering, National Taiwan University, Taipei 106, Taiwan.
authors.forename: Chun-Wei
authors.initials: CW
authors.lastname: Chen
authors.affiliation: Department of Physics, National Taiwan University, Taipei 106, Taiwan.
authors.forename: Chi-Te
authors.initials: CT
authors.lastname: Liang
authors.affiliation: Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan.
authors.forename: Wei-Hua
authors.initials: WH
authors.lastname: Wang