Standardization of surface potential measurements of graphene domains
2013 (English)In: Scientific Reports, ISSN 2045-2322, Vol. 3Article in journal (Refereed) Published
We compare the three most commonly used scanning probe techniques to obtain a reliable value of the work function in graphene domains of different thickness. The surface potential (SP) of graphene is directly measured in Hall bar geometry via a combination of electrical functional microscopy and spectroscopy techniques, which enables calibrated work function measurements of graphene domains in ambient conditions with values Φ1LG ~4.55 ± 0.02 eV and Φ2LG ~ 4.44 ± 0.02 eV for single- and bi-layer, respectively. We demonstrate that frequency-modulated Kelvin probe force microscopy (FM-KPFM) provides more accurate measurement of the SP than amplitude-modulated (AM)-KPFM. The discrepancy between experimental results obtained by different techniques is discussed. In addition, we use FM-KPFM for contactless measurements of the specific components of the device resistance. We show a strong non-Ohmic behavior of the electrode-graphene contact resistance and extract the graphene channel resistivity.
Place, publisher, year, edition, pages
Nature Publishing Group: Open Access Journals - Option B / Nature Publishing Group , 2013. Vol. 3
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-98143DOI: 10.1038/srep02597ISI: 000324016900001OAI: oai:DiVA.org:liu-98143DiVA: diva2:652295
Funding Agencies|NMS under the IRD Graphene Project (NPL)||EU FP7 Project ConceptGraphene||2013-09-302013-09-302013-10-08