title: Vertical and in-plane heterostructures from WS2/MoS2 monolayers.
abstract: Layer-by-layer stacking or lateral interfacing of atomic monolayers has opened up unprecedented opportunities to engineer two-dimensional heteromaterials. Fabrication of such artificial heterostructures with atomically clean and sharp interfaces, however, is challenging. Here, we report a one-step growth strategy for the creation of high-quality vertically stacked as well as in-plane interconnected heterostructures of WS2/MoS2 via control of the growth temperature. Vertically stacked bilayers with WS2 epitaxially grown on top of the MoS2 monolayer are formed with preferred stacking order at high temperature. A strong interlayer excitonic transition is observed due to the type II band alignment and to the clean interface of these bilayers. Vapour growth at low temperature, on the other hand, leads to lateral epitaxy of WS2 on MoS2 edges, creating seamless and atomically sharp in-plane heterostructures that generate strong localized photoluminescence enhancement and intrinsic p-n junctions. The fabrication of heterostructures from monolayers, using simple and scalable growth, paves the way for the creation of unprecedented two-dimensional materials with exciting properties.
authors.affiliation: 1] Department of Chemistry, Rice University, Houston, Texas 77005, USA [2] Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA.
authors.forename: Yongji
authors.initials: Y
authors.lastname: Gong
authors.affiliation: 1] Materials Science and Technology Division, Oak Ridge National Lab, Oak Ridge, Tennessee 37831, USA [2] Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235, USA.
authors.forename: Junhao
authors.initials: J
authors.lastname: Lin
authors.affiliation: 1] School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798 [2] School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798.
authors.forename: Xingli
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA.
authors.forename: Gang
authors.initials: G
authors.lastname: Shi
authors.affiliation: Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA.
authors.forename: Sidong
authors.initials: S
authors.lastname: Lei
authors.affiliation: Department of Physics and Center for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Lin
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: Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA.
authors.forename: Gonglan
authors.initials: G
authors.lastname: Ye
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 Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Johnson-Rowland Science Center, 110 Eighth Street, Troy, New York 12180, USA.
authors.forename: Humberto
authors.initials: H
authors.lastname: Terrones
authors.affiliation: 1] Department of Physics and Center for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, USA [2] Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA [3] Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA [4] Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Terrones
authors.affiliation: 1] School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798 [2] School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798.
authors.forename: Beng Kang
authors.initials: BK
authors.lastname: Tay
authors.affiliation: Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Lou
authors.affiliation: 1] Materials Science and Technology Division, Oak Ridge National Lab, Oak Ridge, Tennessee 37831, USA [2] Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235, USA.
authors.forename: Sokrates T
authors.initials: ST
authors.lastname: Pantelides
authors.affiliation: 1] School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798 [2] School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Materials Science and Technology Division, Oak Ridge National Lab, Oak Ridge, Tennessee 37831, USA.
authors.forename: Wu
authors.initials: W
authors.lastname: Zhou
authors.affiliation: 1] Department of Chemistry, Rice University, Houston, Texas 77005, USA [2] Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA.
authors.forename: Pulickel M
authors.initials: PM
authors.lastname: Ajayan