Figure 3

(a) A two-dimensional nano-ARPES image of the measured integrated intensity of the graphene π-band(s) in the energy range 0 to 0.5 eV below the Fermi level and at the -point at φ = 59° (see Fig. 1). The area shown is 35 × 50 μm², the photon energy used 100 eV and the intensity is provided in a linear scale as a color image. (b)-(e) Nano-ARPES spectra recorded, at φ = 59° along the direction and at hν = 100 eV, from four different graphene grains at the correspondingly labeled positions in (a). In (f) and (g) similar nano-ARPES spectra recorded at φ = 39° from two different graphene grains at other positions on the surface are shown. Theoretical π-band dispersions calculated for (h) two, (i) three, (j) four and (k) five layers of Bernal stacked free standing graphene, using density functional theory.