Fig. 1. (a) Schematic diagram of GNRs-MoS₂ hybrid on the glass substrate. (b) Extinction spectra of GNRs in aqueous solution. Inset: transmission electron micrographs of the GNRs with a scale bar of 100 nm. (c), (d) Optical confocal scanning image and AFM image of the GNRs-MoS₂, respectively. The green and yellow circles indicate the positions of single GNR on glass and MoS₂ monolayer, respectively, with a scale bar of 5 μm.

Fig. 2. Photothermal reshaping of a single GNR on the glass substrate. (a) Scattering spectra of a GNR on the glass tuned by photothermal reshaping effect through controlling the illumination power. The blue-dashed line in (a) is the photoluminescence spectra of the MoS₂ monolayer. (b) FWHM and intensity of scattering spectra during the photothermal reshaping. Inset shows the blue-shift of the plasmon resonance of GNR. The color in (b) corresponds to the color of the scattering spectra in (a). (c) Influence of laser power (~0.11 mW to ~4.16 mW) on monolayer MoS₂ on the glass. (d) PL intensity and A exciton position changes during the photothermal reshaping. Excitation laser wavelength: 532 nm. Excitation power: 110 μW. Integration time: 0.5 s.

Fig. 3. (a) Normalized scattering spectra of a GNR on glass (black), the same GNR moved onto MoS₂ (red), and the GNR on MoS₂ after heating (blue). (b) Photoluminescence spectra of MoS₂ monolayer without (red) and with (black) GNR. The black dashed line in (b) marks the A (right) and B (left) excitons absorption peak. Inset: Raman spectra of MoS₂ monolayer with the A_1g peak (408 cm⁻¹) and E_2g¹ peak (388 cm⁻¹). Excitation laser wavelength: 532 nm. Excitation power: 110 μW. Integration time: 0.5 s. (c) Calculated scattering spectra using the FDTD method corresponding to the experimental spectra shown in (a). Scattering spectra of a GNR (L/D~2.4) on glass (black), the same GNR (L/D~2.4) on MoS₂ (red) and another GNR (L/D~2.2) on MoS₂ (blue). (d) Near-field distributions: the calculated near-field distribution |E| in the x-z plane (y=0 nm) (upper) and in the x-y plane (z=0 nm) (lower), i.e., the interface between GNR and MoS₂.

Fig. 4. Plasmon exciton interaction in the GNR-MoS₂ hybrid. (a) Scattering spectra of individual GNR coupled to the monolayer MoS₂ flake. The vertical purple and grey dashed lines in (a) mark the A and B excitons absorption peaks. (b) Corresponding PL spectra (black line) of GNR-MoS₂ hybrid during the photothermal reshaping. The vertical orange dashed line in (b) marks A exciton absorption peak of MoS₂ with GNR, and the vertical gray dashed line in (b) marks A exciton absorption peak of pristine MoS₂ without GNR. The dashed curve in (b) shows the scattering spectra. (c) Changes in the linewidth of scattering spectra of GNR-MoS₂ hybrid with heating power. The color in (c) corresponds to the color of the scattering spectra in (a). (d) Hybrid plasmon-exciton branches as a function of detuning. The dots (red spheres correspond to upper energy branch, blue sphere to lower energy branch, green squares to plasmon resonance) correspond to extracted experimental values, and the curves are theoretical results. Black and green lines indicate the dispersion of the uncoupled exciton and plasmon, respectively.