In nanoelectronics and optoelectronics, two-dimensional transition metal dichalcogenides (2D TMDC) analogous to graphene have drawn considerable attention due to their electrical and innate band gap characteristics. Among them, MoS₂ and WS₂ show unique properties; direct and indirect band gap of 1.8 eV and 1.2 eV, respectively, depending on the monolayer stacking states. Thin layered WS₂ composed of a S-W-S sandwich crystalline with a van der Waals, possessed the coupled spin and valley physics, high photoluminescence efficiency, and composited layered materials with other 2D for many applications. Most studies on 2D TMDC have been focused on the chemical synthesis using chemical vapor deposition (CVD) and mechanical methods like exfoliated flakes by taping or in liquid. In contrast, large scale synthesis of WS₂ via solution-process is rare to find.

Here, we have prepared new synthetic route combining solution coating and CVD process together. The solution of sodium tungstate soulution and hydrizene hydrate with sodium thiosulphate was coated on the silicon wafer. The coated films from dip coating and spin coating were treated in the CVD with different paramerters to obtain WS2 crystal structures. The temperature and coating conditions were modified to obtain uniform wafer-scale films. The average of 50 um size WS2 crystals with triangle shapes could be obtained at the low temperatures of 700^oC and above with sample positions in the CVD.