Figure 1.

Plasmonic resonances in SLG and DLG nanoribbons. (a) Conceptual representation of the excitation of localized surface plasmon resonances in a 2L-GNRA by illumination with mid-infrared radiation. The top graphene layer is transferred directly over the bottom layer without an interlayer spacer. Graphene nanoribbons are patterned with a width W and periodicity P. (b) Surface topography image measured with an atomic force microscope and (c) scanning electron microscope image of one of the fabricated 2L-GNRAs (W=50 nm, P=105 nm). (d) Experimental extinction spectra of 2L-GNRAs (solid curves) with different widths (W=25, 33, 40, 50 nm and P≈2W). The 2L-GNRA spectra are compared against those of 1L-GNRAs (dashed curves) with identical width and periodicity. The extinction is calculated as 1−T/T₀, where T and T₀ are the transmission coefficients with and without GNRAs, respectively.