title: Toward Clean Suspended CVD Graphene.
abstract: The application of suspended graphene as electron transparent supporting media in electron microscopy, vacuum electronics, and micromechanical devices requires the least destructive and maximally clean transfer from their original growth substrate to the target of interest. Here, we use thermally evaporated anthracene films as the sacrificial layer for graphene transfer onto an arbitrary substrate. We show that clean suspended graphene can be achievedviadesorbing the anthracene layer at temperatures in the 100 °C to 150 °C range, followed by two sequential annealing steps for the final cleaning, using Pt catalyst and activated carbon. The cleanliness of the suspended graphene membranes was analyzed employing the high surface sensitivity of low energy scanning electron microscopy and x-ray photoelectron spectroscopy. A quantitative comparison with two other commonly used transfer methods revealed the superiority of the anthracene approach to obtain larger area of clean, suspended CVD graphene. Our graphene transfer method based on anthracene paves the way for integrating cleaner graphene in various types of complex devices, including the ones that are heat and humidity sensitive.
authors.affiliation: Center for Nanoscale Science and Technology, NIST, Gaithersburg, MD 20899, USA; Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742, USA; Maryland NanoCenter, University of Maryland, College Park, MD 20742, USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Yulaev
authors.affiliation: Physical Measurement Laboratory, NIST, Gaithersburg, MD 20899, USA.
authors.forename: Guangjun
authors.initials: G
authors.lastname: Cheng
authors.affiliation: Physical Measurement Laboratory, NIST, Gaithersburg, MD 20899, USA.
authors.forename: Angela R Hight
authors.initials: AR
authors.lastname: Walker
authors.affiliation: Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
authors.forename: Ivan V
authors.initials: IV
authors.lastname: Vlassiouk
authors.affiliation: Center for Nanoscale Science and Technology, NIST, Gaithersburg, MD 20899, USA.
authors.forename: Alline
authors.initials: A
authors.lastname: Myers
authors.affiliation: Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742, USA; Institute for Research in Electronics and Applied Physics, University of Maryland, College Park 20742, USA.
authors.forename: Marina S
authors.initials: MS
authors.lastname: Leite
authors.affiliation: Center for Nanoscale Science and Technology, NIST, Gaithersburg, MD 20899, USA.
authors.forename: Andrei
authors.initials: A
authors.lastname: Kolmakov
keywords: anthracene; graphene transfer; purity; scanning electron microscopy