Revealing the planar chemistry of two-dimensional heterostructures at the atomic level

Harry Chou; Ariel Ismach; Rudresh Ghosh; Rodney S Ruoff; Andrei Dolocan

doi:10.1038/ncomms8482

Revealing the planar chemistry of two-dimensional heterostructures at the atomic level

Nat Commun. 2015 Jun 23:6:7482. doi: 10.1038/ncomms8482.

Authors

Harry Chou¹, Ariel Ismach², Rudresh Ghosh³, Rodney S Ruoff⁴, Andrei Dolocan⁵

Affiliations

¹ 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.
² 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.
³ Microelectronics Research Center, The University of Texas at Austin, Austin, Texas 78758, USA.
⁴ 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.
⁵ Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, USA.

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.