title: Strain and structure heterogeneity in MoS2 atomic layers grown by chemical vapour deposition.
abstract: Monolayer molybdenum disulfide (MoS2) has attracted tremendous attention due to its promising applications in high-performance field-effect transistors, phototransistors, spintronic devices and nonlinear optics. The enhanced photoluminescence effect in monolayer MoS2 was discovered and, as a strong tool, was employed for strain and defect analysis in MoS2. Recently, large-size monolayer MoS2 has been produced by chemical vapour deposition, but has not yet been fully explored. Here we systematically characterize chemical vapour deposition-grown MoS2 by photoluminescence spectroscopy and mapping and demonstrate non-uniform strain in single-crystalline monolayer MoS2 and strain-induced bandgap engineering. We also evaluate the effective strain transferred from polymer substrates to MoS2 by three-dimensional finite element analysis. Furthermore, our work demonstrates that photoluminescence mapping can be used as a non-contact approach for quick identification of grain boundaries in MoS2.
authors.affiliation: 1] School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore [2] NOVITAS, Nanoelectronics Centre of Excellence, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore [3] CINTRA CNRS/NTU/THALES, UMI 3288, Research Techno Plaza, 50 Nanyang Drive, Border X Block, Level 6, Singapore 637553, Singapore.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Sensors and Electron Devices Directorate, US Army Research Laboratory, Adelphi, Maryland 20783, USA.
authors.forename: Matin
authors.initials: M
authors.lastname: Amani
authors.affiliation: Department of Materials Science and Nanoengineering, Rice University, Houston, Texas 77005, USA.
authors.forename: Sina
authors.initials: S
authors.lastname: Najmaei
authors.affiliation: 1] Department of Materials Science and Engineering, University of North Texas, 1155 Union Circle, Denton, Texas 76203, USA [2] Institute of New Energy, China University of Petroleum (Beijing), Beijing 102200, China.
authors.forename: Quan
authors.initials: Q
authors.lastname: Xu
authors.affiliation: Department of Materials Science and Nanoengineering, Rice University, Houston, Texas 77005, USA.
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Zou
authors.affiliation: Materials Science &Technology Division, Oak Ridge National Lab, Oak Ridge, Tennessee 37831, USA.
authors.forename: Wu
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore.
authors.forename: Ting
authors.initials: T
authors.lastname: Yu
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore.
authors.forename: Caiyu
authors.initials: C
authors.lastname: Qiu
authors.affiliation: Sensors and Electron Devices Directorate, US Army Research Laboratory, Adelphi, Maryland 20783, USA.
authors.forename: A Glen
authors.initials: AG
authors.lastname: Birdwell
authors.affiliation: Sensors and Electron Devices Directorate, US Army Research Laboratory, Adelphi, Maryland 20783, USA.
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Crowne
authors.affiliation: Department of Materials Science and Nanoengineering, Rice University, Houston, Texas 77005, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Vajtai
authors.affiliation: Department of Materials Science and Nanoengineering, Rice University, Houston, Texas 77005, USA.
authors.forename: Boris I
authors.initials: BI
authors.lastname: Yakobson
authors.affiliation: Department of Materials Science and Engineering, University of North Texas, 1155 Union Circle, Denton, Texas 76203, USA.
authors.forename: Zhenhai
authors.initials: Z
authors.lastname: Xia
authors.affiliation: Sensors and Electron Devices Directorate, US Army Research Laboratory, Adelphi, Maryland 20783, USA.
authors.forename: Madan
authors.initials: M
authors.lastname: Dubey
authors.affiliation: Department of Materials Science and Nanoengineering, Rice University, Houston, Texas 77005, USA.
authors.forename: Pulickel M
authors.initials: PM
authors.lastname: Ajayan
authors.affiliation: Department of Materials Science and Nanoengineering, Rice University, Houston, Texas 77005, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Lou