Fig. 2
From: Origin of ultrafast growth of monolayer WSe2 via chemical vapor deposition
a Diagram classifying the growth conditions based on the different ratio of attachment rate (rat) to the edge diffusion rate (red) and to the surface diffusion rate (rdi). Domain morphologies at 800 °C with b Eed = 0.5 eV, c Eed = 1.0 eV, and d Eed = 1.5 eV, respectively, at FS = 2.0 × 10−2 ML/s and FW = 1.8 × 10−2 ML/s. b–d Scale bar: 10a (a = 0.332 nm). e Growth rate of the edge length as a function of time at 800 °C with Eed = 0.5 eV. f Schematic illustration of the six energetically favorable sites for in-plane diffusion of W atom along the Se-terminated zigzag edge. Purple, orange, and gray spheres represent W, Se, and Au atoms, respectively. g The energy barriers for edge diffusion obtained from first-principles calculations: red: site 2 to site 3, green: site 3 to site 4, and blue: site 4 to site 5
