title: Revealing the planar chemistry of two-dimensional heterostructures at the atomic level.
abstract: Two-dimensional (2D) atomic crystals and their heterostructures are an intense area of study owing to their unique properties that result from structural planar confinement. Intrinsically, the performance of a planar vertical device is linked to the quality of its 2D components and their interfaces, therefore requiring characterization tools that can reveal both its planar chemistry and morphology. Here, we propose a characterization methodology combining (micro-) Raman spectroscopy, atomic force microscopy and time-of-flight secondary ion mass spectrometry to provide structural information, morphology and planar chemical composition at virtually the atomic level, aimed specifically at studying 2D vertical heterostructures. As an example system, a graphene-on-h-BN heterostructure is analysed to reveal, with an unprecedented level of detail, the subtle chemistry and interactions within its layer structure that can be assigned to specific fabrication steps. Such detailed chemical information is of crucial importance for the complete integration of 2D heterostructures into functional devices.
authors.affiliation: 1] Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA [2] Microelectronics Research Center, The University of Texas at Austin, Austin, Texas 78758, USA.
authors.forename: Harry
authors.initials: H
authors.lastname: Chou
authors.affiliation: 1] Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA [2] Department of Materials Science and Engineering, Tel Aviv University, Ramat Aviv 6997801, Israel.
authors.forename: Ariel
authors.initials: A
authors.lastname: Ismach
authors.affiliation: Microelectronics Research Center, The University of Texas at Austin, Austin, Texas 78758, USA.
authors.forename: Rudresh
authors.initials: R
authors.lastname: Ghosh
authors.affiliation: 1] Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA [2] Center for Multidimensional Carbon Materials, Institute of Basic Sciences Center, Ulsan National Institute of Science and Technology, Ulsan 689-798, Republic of Korea.
authors.forename: Rodney S
authors.initials: RS
authors.lastname: Ruoff
authors.affiliation: Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Andrei
authors.initials: A
authors.lastname: Dolocan