Fig. 4: Polarization resolved PL characterization.

a Optical image of a bare WS₂ monolayer (scale bar is 10 μm). b–d SEM images of silver sawtooth nanoslits with θ = 30° (b), 45° (c) and 55° (d), respectively. Scale bar is 500 nm. The inserts at the top right corner show two unit cells of the corresponding array. e–h Normalized PL spectra of bare WS₂ monolayer and three hybrid nanostructures with a peak at ~636 nm for the detection angle along TE (black curve) and TM (red curve) polarization directions respectively. i–l Normalized PL peak intensity, as a function of the detection angle for a given incident laser polarization (marked by the green arrow) for WS₂ monolayer (i) and three hybrid nanostructures (j–l), respectively. 0 corresponds to the center and 1.0 to the outermost dashed line.