Controllable synthesis of monolayer WSe2 crystals by Copper-Assisted chemical vapor deposition

In this work, we demonstrate the controllable synthesis of high-quality WSe2 monolayers via a copper-assisted chemical vapor deposition method. The structure characterizations confirm that the as-grown WSe2 crystals by introducing Cu powder exhibit monolayer thickness and high crystalline quality. Most importantly, theoretical calculation reveals that Cu atoms could easily occupy the active sites above the monolayer WSe2 surface, consequently forming a self-limited growth. The Cu-assisted growth method broadens the scope of the 2D growth of other TMD materials, and also provides more application potential in 2D electronics.