Fig. 2: 2M to 2H phase transition mechanism of WS2.
a Crystal structures of 1T′ WS2, where W and S atoms coordinate in an octahedral configuration and stack in an A/A’-B/B’-C/C’ mode. b Crystal structures of 1H WS2, where W and S atoms coordinate in a trigonal prismatic configuration and stack in an A-B-A mode. c Top view (upper) and side view (lower) of crystal lattices when overlapping of a layer of 1T′ WS2 on top of a layer of 1H WS2. Color code: blue and orange spheres represent W and S, respectively. The broken W‒W and W‒S bonds are labeled by dash lines, and the directions of W and S atoms displacements are indicated by orange arrows. Each S atom that dissociates from a W atom after breaking the W‒S bond moves to a new position (marked by a dotted line circle) and forms a new W‒S bond.
