Raman imaging of doping domains in graphene on SiO2

C. Stampfer , L. Wirtz (1) , A. Jungen , F. Molitor , D. Graf , C. Hierold , K. Ensslin

1 IEMN - Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520

We present spatially resolved Raman images of the G and 2D lines of single-layer graphene flakes. The spatial fluctuations of G and 2D lines are correlated and are thus shown to be affiliated with local doping domains. We investigate the position of the 2D line – the most significant Raman peak to identify single-layer graphene – as a function of charging up to |n| ≈ 4 × 1012 cm−2. Contrary to the G line which exhibits a strong and symmetric stiffening with respect to electron and hole-doping, the 2D line shows a weak and slightly asymmetric stiffening for low doping. Additionally, the line width of the 2D line is, in contrast to the G line, doping-independent making this quantity a reliable measure for identifying single-layer graphene

Domaines: Sciences de l'ingénieur [physics]

C. Stampfer, L. Wirtz, A. Jungen, F. Molitor, D. Graf, et al.. Raman imaging of doping domains in graphene on SiO2. Applied Physics Letters, 2007, 91, pp.241907-1-3. ⟨10.1063/1.2816262⟩. ⟨hal-00283188⟩