Figure 1: RDS of aligned GNRs.
From: Exciton-dominated optical response of ultra-narrow graphene nanoribbons
(a) Schematic of the RDS experiment on uniaxially aligned 7-AGNRs on a vicinal surface. (b) STM topography image (Usample =−1.5 V; scale bar, 20 nm) of aligned 7-AGNRs grown on Au(788). The inset shows a small-scale STM image (Usample=−2.2 V; 4.1 × 1.2 nm2) and the chemical structure of a hydrogen-terminated 7-AGNR. (c) Measured (open circles) and fitted (solid lines) RD spectra of 7-AGNR on Au(788) measured in situ after GNR synthesis. The RD spectrum of the pristine Au substrate has been subtracted. The bottom panel shows the differential dielectric function Δε obtained from the RD spectrum by applying the three-phase model (open symbols) and the fit to a model including three discrete harmonic oscillator transitions (lines). The blue bars indicate the energy position and oscillator strength (maximum of ε2≈Am/(EmΓm)) of the determined optical transitions (see Methods).
