Fig. 2
From: Strong-coupling of WSe2 in ultra-compact plasmonic nanocavities at room temperature
WSe2 stack properties. a Dark-field image with 10 μm scale bar (solid white line), b Bright-field and c AFM images of multilayer WSe2 stack. The AFM height profile of flake edge (white dashed line) gives d = 10 ± 0.4 nm, corresponding to 12 layers. d Power-dependent emission (Input power ranges from 0 to 30 μW μm−2 in steps of 2.5) at room temperature of the multilayer stack (brown) and NPoM (purple). Vertical lines mark A exciton absorption peak (black) and polariton peaks (purple). e Scattering and PL emission spectra on same NPoM, dashed line marks exciton absorption peak. f Scaling of integrated emission intensity with pump power for polaritons (orange curve) in NPoM (background subtracted) and (grey) excitons in multilayer on Au substrate. Error bars result from experimental noise and are extracted from the standard error of the background counts. Purple shading indicates the nonlinear emission regime
