Full text loading...
(a) STM image of N-doped bilayer graphene/SiC(0001) (Vs = −0.23 V, It = 1.0 nA). (b) Fourier transform of the STM image in (a), showing the √3 ×√3 pattern induced by defect scattering. (c) Schematic representation of the graphene 2D Brillouin zone, indicating the possible intervalley scattering process. Atomic resolution images of three variants of type I defect: (d) type IA (Vs = 0.1 V, It = 0. 4 nA), (e) type IB (Vs = −0.2 V, It = 0.5 nA), and (f) type IC (Vs = −0.5 V, It = 1.0 nA). The arrows in (e) and (f) point to the brighter and dimmer spots, respectively. All images were taken at room temperature, except (b) that was taken at 77 K.
(a) Ball-and-stick-model for α, β, and γ N-vacancy complexes; (b)-(f) DOS plots for NC, VC, and α, β, γ N-vacancy complexes, respectively.
Iso-DOS plots for the occupied (EF-0.5 eV) and unoccupied (EF+0.5 eV) states for the NC, VC, and α, β, γ N-vacancy complexes, where red (yellow) spheres denote N (C) atoms.
Calculated k-projected bands of the (single layer) α configuration along K−Γ in the primitive graphene Brillouin zone. (b) Enlarged view around K point. The arrows indicate impurity bands and the circle denotes the mid-gap defect state. (c) Calculated C 1s core level shifts. Inset: Schematic of the carbon atoms grouped according to the calculated core level shifts in the same color, where N atom is shown in black. (d) Calculated N 1s core spectrum for a distribution of N defects relative to the energy of the Nc configuration. Positive core level shifts correspond to shifts towards EF, i.e., decreased binding energy. To simulate lifetime and instrumental broadening, the calculated C (N) shifts were convoluted with Gaussians of 0.25 eV (1 eV) FWHM.
Article metrics loading...