Transformation from dendritic to triangular WS₂ growth via NaCl assisted low pressure chemical vapor deposition.

Tungsten disulfide (WS₂) has captured the attention of the materials community due to its unique optical and electrical properties. NaCl assisted Low-Pressure Chemical Vapor Deposition methods can be applied to grow large scale, monolayer WS₂ crystals on silicon substrates. In this work, we find a clear transition between dendritic and triangular growth while varying growth parameters. Specifically, the morphology of the resultant WS₂ was significantly varied with amount of promoter material, process temperature, and precursor material distance. The resultant growth was characterized by Raman spectroscopy, scanning electron microscopy, and X-ray photoemission spectroscopy to quantify the impact of varying growth conditions. This work provides key insights into the role of NaCl on the growth of large-scale WS2 in salt-assisted Low-Pressure Chemical Vapor Deposition.