title: Microsteganography on WS2Monolayers Tailored by Direct Laser Painting.
abstract: We present scanning focused laser beam as a multipurpose tool to engineer the physical and chemical properties of WS2microflakes. For monolayers, the laser modification integrates oxygen into the WS2microflake, resulting in ∼9 times enhancement in the intensity of the fluorescence emission. This modification does not cause any morphology change, allowing "micro-encryption" of information that is only observable as fluorescence under excitation. The same focused laser also facilitates on demand thinning down of WS2multilayers into monolayers, turning them into fluorescence active components. With a scanning focused laser beam, micropatterns are readily created on WS2multilayers through selective thinning of specific regions on the flake.
authors.affiliation: NUS High School of Mathematics and Science , 20 Clementi Avenue 1, Singapore 129957.
authors.forename: Ashwin
authors.initials: A
authors.lastname: Venkatakrishnan
authors.affiliation: NUS High School of Mathematics and Science , 20 Clementi Avenue 1, Singapore 129957.
authors.forename: Hou
authors.initials: H
authors.lastname: Chua
authors.affiliation: NUS High School of Mathematics and Science , 20 Clementi Avenue 1, Singapore 129957.
authors.forename: Pinxi
authors.initials: P
authors.lastname: Tan
authors.affiliation: Department of Physics, National University of Singapore , 2 Science Drive 3, Singapore 117542.
authors.forename: Zhenliang
authors.initials: Z
authors.lastname: Hu
authors.affiliation: Institute of Materials Research and Engineering, Agency for Science, Technology, and Research (A*STAR) , 2 Fusionopolis Way, lnnovis, #08-03, Singapore 138634.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Liu
authors.affiliation: Center for Advanced 2D Materials and Graphene Research Center, National University of Singapore , 6 Science Drive 3, Singapore 117546.
authors.forename: Yanpeng
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Center for Advanced 2D Materials and Graphene Research Center, National University of Singapore , 6 Science Drive 3, Singapore 117546.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Carvalho
authors.affiliation: Department of Physics, National University of Singapore , 2 Science Drive 3, Singapore 117542.|Center for Advanced 2D Materials and Graphene Research Center, National University of Singapore , 6 Science Drive 3, Singapore 117546.
authors.forename: Junpeng
authors.initials: J
authors.lastname: Lu
authors.affiliation: Department of Physics, National University of Singapore , 2 Science Drive 3, Singapore 117542.|Center for Advanced 2D Materials and Graphene Research Center, National University of Singapore , 6 Science Drive 3, Singapore 117546.
authors.forename: Chorng Haur
authors.identifier: 0000-0001-6385-3017
authors.initials: CH
authors.lastname: Sow
keywords: WS2 TMDs; fluorescence; laser modification; micropatterning