Fig. 2

a, b Illustrate how to calculate the AGRs of monolayer WS2 flakes with different shapes, including c hexagon, d upward triangle, and e downward triangle, where the downward trianglar flake is terminated by three W-zigzag (-zz) edges, the upward by three S-zz edges, and the hexgonal by both three W-zz and three S-zz edges