Effect of Substrate symmetry on the dendrite morphology of MoS2 Film synthesized by CVD Article Swipe
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· 2017
· Open Access
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· DOI: https://doi.org/10.1038/s41598-017-13238-x
· OA: W2767088176
In van der Waals epitaxial growth, the substrate plays a particularly important role in the crystal morphology. Here, we synthesized MoS 2 by chemical vapour deposition on silicon carbide (SiC). The obtained MoS 2 dendritic crystals show six-fold symmetry, which are different from the conventional triangular shapes on SiO 2 substrate and from those with three-fold symmetry on SrTiO 3 substrate. Interestingly, these MoS 2 dendritic crystals on SiC exhibit an average fractal dimension 1.76, which is slightly larger than the classical Diffusion-limited-Aggregation fractal dimension 1.66. The first principle calculation indicates that the six-fold symmetry of the dendritic MoS 2 is determined by the lattice symmetry of SiC. To further demonstrating the substrate effect, we break the natural six-fold lattice symmetry of SiC (0001) into groove arrays through etching the substrate. And then we successfully synthesized cross-type dendritic crystal MoS 2 with two-fold symmetry. Its average fractal dimension 1.83 is slightly larger than the fractal dimension 1.76 of the previous MoS 2 dendrite with six-fold symmetry. In a word, the symmetry of SiC substrate determined the symmetry and the fractal dimension of the dendritic MoS 2 . This work provides one possibility of inducing the growth orientation of dendritic crystals through controlling the substrate surface symmetry artificially.
