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arXiv · 0709.2566

Raman Fingerprint of Charged Impurities in Graphene

C. Casiraghi·S. Pisana·K. S. Novoselov·A. K. Geim·A. C. Ferrari
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Abstract

We report strong variations in the Raman spectra for different single-layer graphene samples obtained by micromechanical cleavage, which reveals the presence of excess charges, even in the absence of intentional doping. Doping concentrations up to ~10^13 cm-2 are estimated from the G peak shift and width, and the variation of both position and relative intensity of the second order 2D peak. Asymmetric G peaks indicate charge inhomogeneity on the scale of less than 1 micron.

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C. Casiraghi, S. Pisana, K. S. Novoselov, A. K. Geim, A. C. Ferrari. 2007-09-17. Raman Fingerprint of Charged Impurities in Graphene. https://doi.org/10.1063/1.2818692

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