Formation mechanism of 2D WS2 with different morphology by chemical vapor deposition

Exploring materials formation mechanism and shape evolution during the growth of nanomaterials is vital for controllable synthesis and improving the crystal quality. Here, two dimensional WS2 films were synthesized on Si/SiO2 substrates via atmospheric pressure chemical vapor deposition. Different shapes of WS(2)( )films scattered on the surface of substrate can be obtained simultaneously under the same experimental condition. We find that the edge free energy of different edges competes with each other, which promotes the growth of two dimensional WS2. Besides, the local ratio between W and S atoms of precursors on the surface of substrates can also influence the growth process and the final morphology of WS2 films. This work is helpful in further understanding the growth mechanism of 2D films and then further modulating the quality of 2D materials.