title: High-Performance MoS2/CuO Nanosheet-on-One-Dimensional Heterojunction Photodetectors.
abstract: van der Waals heterostructures based on stacked two-dimensional (2D) materials provide novel device structures enabling high-performance electronic and optoelectronic devices. While 2D-2D or 2D-bulk heterostructures have been largely explored for fundamental understanding and novel device applications, 2D-one-dimensional (1D) heterostructures have been rarely studied because of the difficulty in achieving high-quality heterojunctions between 2D and 1D structures. In this study, we introduce nanosheet-on-1D van der Waals heterostructure photodetectors based on a wet-transfer printing of a MoS2nanosheet on top of a CuO nanowire (NW). MoS2/CuO nanosheet-on-1D photodetectors show an excellent photocurrent rectification ratio with an ideality factor of 1.37, which indicates the formation of an atomically sharp interface and a high-quality heterojunction in the MoS2/CuO heterostructure by wet-transfer-enhanced van der Waals bonding. Furthermore, nanosheet-on-1D heterojunction photodetectors exhibit excellent photodetection capabilities with an ultrahigh photoresponsivity (∼157.6 A/W), a high rectification ratio (∼6000 at ±2 V), a low dark current (∼38 fA at -2 V), and a fast photoresponse time (∼34.6 and 51.9 ms of rise and decay time), which cannot be achievable with 1D-on-nanosheet heterojunction photodetectors. The wet-transfer printing of nanosheet-on-1D heterostructures introduced in this study provides a robust platform for the fundamental study of various combinations of 2D-on-1D heterostructures and their applications in novel heterojunction devices.
authors.affiliation: School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology , Ulsan 689-798, Korea.
authors.forename: Doo-Seung
authors.initials: DS
authors.lastname: Um
authors.affiliation: School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology , Ulsan 689-798, Korea.
authors.forename: Youngsu
authors.initials: Y
authors.lastname: Lee
authors.affiliation: School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology , Ulsan 689-798, Korea.
authors.forename: Seongdong
authors.initials: S
authors.lastname: Lim
authors.affiliation: School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology , Ulsan 689-798, Korea.
authors.forename: Seungyoung
authors.initials: S
authors.lastname: Park
authors.affiliation: School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology , Ulsan 689-798, Korea.
authors.forename: Hochan
authors.initials: H
authors.lastname: Lee
authors.affiliation: School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology , Ulsan 689-798, Korea.
authors.forename: Hyunhyub
authors.initials: H
authors.lastname: Ko
keywords: CuO nanowire; MoS2; nanosheet-on-1D heterojunction; photodetector; wet-transfer printing