Effect of epitaxial graphene morphology on adsorption of ambient speciesShow others and affiliations
2019 (English)In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 486, p. 239-248Article in journal (Refereed) Published
Abstract [en]
This work illustrates the impact of atmospheric gases on the surface of epitaxial graphene. The different rate of adsorption on different parts of graphene samples provides a concrete evidence that the surface morphology of graphene plays a significant role in this process. The uneven adsorption occurs only on the surface of the monolayer graphene and not on bilayer graphene. The second monolayer is distinguished and verified by the phase contrast mode of atomic force microscopy and the low energy electron microscopy, respectively. Raman spectroscopy is used to study the strain on the surface of graphene; results indicate that monolayer and bilayer graphene exhibit different types of strain. The bilayer is under more compressive strain in comparison with monolayer graphene that hinders the process of adsorption. However, the wrinkles and edges of steps of the bilayer are under tensile strain, hence, facilitate adsorption. Samples were subjected to X-ray photoelectron spectroscopy which confirms that the adsorbates on the epitaxial graphene are carbon clusters with nitrogen and oxygen contamination. For reversing the adsorption process the samples are annealed and a method for the removal of these adsorbates is proposed.
Place, publisher, year, edition, pages
ELSEVIER SCIENCE BV , 2019. Vol. 486, p. 239-248
Keywords [en]
Epitaxial graphene; Adsorption; Strain
National Category
Materials Chemistry
Identifiers
URN: urn:nbn:se:liu:diva-158807DOI: 10.1016/j.apsusc.2019.04.247ISI: 000471748100026OAI: oai:DiVA.org:liu-158807DiVA, id: diva2:1337793
Note
Funding Agencies|European Union Horizon 2020 research and innovation programme [696656]; Graphene Flagship [CNECT-ICT-604391]; VR [621-2014-5805]; SSF [GMT14-0077]; Angpanneforeningens Forskningsstiftelse [16-541]
2019-07-172019-07-172019-07-17