Fig. 1. (a) Schematic diagram of the silver nanogroove array. (b) Reflection spectrum of the silver nanogroove array with pitch p=570  nm, width l=255  nm, and depth d1=110  nm. (c) Distribution of electric field |E/E0| in the silver nanogroove array at the reflection dip wavelength of 630 nm.

Fig. 2. (a) SEM image of the fabricated silver nanogroove array. (b) AFM image of the silver nanogroove array. (c) AFM-measured height profile along the white line in (b). (d) Experimentally measured reflection spectrum of the silver nanogroove array with p=570  nm, l=255  nm, d1=110  nm, and d2=182  nm.

Fig. 3. (a) Schematic diagram of the WS2/silver nanogroove array hybrid structure. (b) Optical microscope image of the WS2 atomic layer transferred on the silver nanogroove array. (c) Raman spectrum of the WS2 atomic layer. (d) Measured and fitting reflection spectra of the WS2/silver nanogroove array structure with p=570  nm, l=255  nm, d1=110  nm, and d2=182  nm. Here, the red curve denotes the reflection spectrum fitted by using temporal coupled-mode theory.

Fig. 4. Experimentally measured reflection spectra of the WS2/silver nanogroove array hybrid structure with different temperatures.

Fig. 5. (a) PL spectra of the WS2 atomic layer without and with the nanogroove array. The inset shows the PL intensity mapping image of the marked region in Fig. 3(b) spectrally integrated from 620 to 640 nm. (b) PL spectra of WS2 on the silver nanogroove array with different temperatures.