Graphene as a two-dimensional material is prone to hydrocarbon contaminations, which can significantly alter its intrinsic electrical properties. Herein, we implement a facile hydrogenation-dehydrogenation strategy to remove hydrocarbon contaminations and preserve the excellent transport properties of monolayer graphene. Using electron microscopy we quantitatively characterized the improved cleanness of hydrogenated graphene compared to untreated samples. In situ spectroscopic investigations revealed that the hydrogenation treatment promoted the adsorption ofytyt water at the graphene surface, resulting in a protective layer against the re-deposition of hydrocarbon molecules. Additionally, the further dehydrogenation of hydrogenated graphene rendered a more pristine-like basal plane with improved carrier mobility compared to untreated pristine graphene. Our findings provide a practical post-growth cleaning protocol for graphene with maintained surface cleanness and lattice integrity to systematically carry a range of surface chemistry in the form of a well-performing and reproducible transistor. [Figure not available: see fulltext.].
Bibliographical noteFunding Information:
This work was supported by the Chinese Scholarship Council (201406890016), NWA route ‘meten & detecteren’, the European Research Council under the European Union’s Seventh Framework Program (FP/2007–2013)/ERC Grant Agreement No. 335879 project acronym ‘Biographene’, the Netherlands Organization for Scientific Research (Vidi 723.013.007). L. Wu and J. P. Hofmann acknowledge funding from The Netherlands Organization for Scientific Research (NWO) and cofinancing by Shell Global Solutions International B.V. for the project 13CO2-6. E.J.M. H. and V.M. acknowledge support by the Netherlands Center for Multiscale Catalytic Energy Conversion (MCEC), an NWO Gravitation program funded by the Ministry of Education, Culture and Science of the government of the Netherlands and a Vici grant of the NWO.
© 2021, The Author(s).
- in situ spectroscopy
- reversible hydrogenation
- surface cleanness