Fig. 2. Highly polarized emission from WSe₂ quantum emitters with three-pointed star (TS) shaped pillars.

a A sketch of monolayer-based WSe₂ quantum emitters with a star-shaped nanopillar design with a high aspect ratio. b AFM image of a WSe₂ monolayer flake deposited on the TS nanostructure depicted in (a). The inset in b shows the corresponding SEM image. Both images reveal the nanowrinkles forming along the vertices of the TS. The directionality of the formed nanowrinkles mostly follows the directions of the vertices. c Corresponding PL image taken at T = 4 K of the fabricated sample exhibits brighter localized emission signals along the nanowrinkles, in contrast to the planar region. The two orthogonal axes are given as a reference for the subsequent polarization-resolved spectra and polar plots. In both (b) and (c), the three collection regions (P1–3) are highlighted. d–f In-plane polarization-resolved PL spectra taken from three highlighted regions (P1–3), respectively. The presented PL spectra in (d–f) are measured under parallel and orthogonal in-plane polarization with respect to the direction of each nanowrinkle. g–i Corresponding polar plots of the polarization-resolved PL intensities for each peak, color-coded to match the graphs in (d–f). The solid lines represent sinusoidal fits⁵⁴ of the data, revealing a degree of linear polarization of 99 ± 4%, 82 ± 14%, and 93 ± 3%, respectively.