Full text loading...
(a) Typical Raman spectra of covered (black) and plasma treated (red) parts of graphene supported on Si/SiO2. (b) Optical microscope image of the silicon stencil maskused for plasma microlithography. (c)20 × 20 μm2 (80 × 80 pixels) Raman microscopy of patterned graphene, showing a clear increase of the D peak to G peak intensity ratio at the plasma treated areas.
10 × 10 μm2 (a) topography and (b) CPD images of the pristine graphene layer supported on a Si/SiO2 substrate, measured in a dry nitrogen atmosphere.
10 × 10 μm2 (a) topography and (b) CPD images of CVD grown graphene patterned with hydrogen plasma microlithography. Darker CPD contrasts are the plasma exposed areas. (c) CPD profile of the A-A′ line in (b). The histogram of (b) is shown in (d), in which the three Gaussian peaks correspond to 3 different contrasts of the CPD image. The difference between peaks (i) and (iii) which correspond to the dark and bright areas is 60 ± 20 meV. Peak (ii) is due to the averaging effects and corresponds to the areas in between dark and bright areas.
(a) CPD image of patterned graphene after annealing at in UHV. Potential diagram of graphene supported on clean Si/SiO2 before (b) and after (c) hydrogen plasma treatment. Wgr denotes the work function of a free standing graphene. is the potential drop across the graphene SiO2 interface. Ev and Ef are the vacuum level and the Fermi level, respectively. is the energy loss to the surface charge density of graphene created as a result of electrostatic charging at equilibrium distance d with respect to the substrate subscripts i and f denote the pristine and hydrogen plasma treated graphene, respectively.
Article metrics loading...