1. Scanning probe microscopy investigation of the mechanisms limiting electronic transport in substrate-supported graphene.
- Author
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Giannazzo, F., Fisichella, G., Nigro, R. Lo, Fiorenza, P., Franco, S. Di, Marino, A., Piluso, N., Rimini, E., and Roccaforte, F.
- Subjects
SCANNING probe microscopy ,GRAPHENE ,PERMITTIVITY measurement ,STRONTIUM titanate ,HISTOGRAMS ,INDUSTRIAL contamination - Abstract
The scattering mechanisms limiting electronic transport in substrate-supported graphene have been investigated by mapping the electron mean free path (l) in graphene on substrates with different dielectric permittivities, i.e. SiO
2 (κSiO2 =3.9), 4H-SiC (0001) (κSiC =9.7) and SrTiO3 (001) (κSrTiO3 =330). From the analysis of the local l versus gate bias curves, histograms and nanoscale maps of the densities of charged impurities (NCI ) have been extracted. l was found to increase from (107±6) nm to (218±11) nm moving from SiO2 to SiC substrate, whereas a decrease to (179±5)nm was found for gra- phene on SrTiO3 . Furthermore, a clear correlation between the minima in the l maps and the maxima in the NCI maps was obtained for graphene on SiO2 and SiC, whereas the two maps are uncorrelated in graphene on SrTiO3 . These results indicate that charged impurity scattering is the main source of the lateral inhomogeneity of l on lower κ substrates, like SiO2 and SiC, whereas a different scattering mechanism (probably resonant scattering) must be invoked as the origin of the nanoscale variations of l in graphene on high-κ substrates like SrTiO3 . (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]- Published
- 2013
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