In this paper, two-dimensional ultrathin films of tungsten diselenide (2D-WSe2)are synthesized on Si/SiO2 substrate by using two approaches, physical vapordeposition (PVD) and chemical vapor deposition (CVD). The essential parametersof deposition conditions including temperature, pressure, and gas flow of bothmethods are presented. The samples were examined for their morphology by opticalmicroscopy (OM), scanning electron microscopy (SEM), atomic force microscopy(AFM), and for the crystal lattice vibration properties by Raman scattering spectrum.The results show that the single crystal flakes are located separately in hexagonal ortriangular shapes with edge lengths ranging from 20 µm to 100 µm, or can be linkedtogether to form a continuous film. The thickness of most of the film area obtainedfrom both methods can be controlled to a single layer (1L-WSe2). In addition, thephotoluminescence spectra (PL) of the samples were investigated, which indirectlyevaluated the crystallization quality of the thin films prepared from the two methods.In this paper, two-dimensional ultrathin films of tungsten diselenide (2D-WSe2)are synthesized on Si/SiO2 substrate by using two approaches, physical vapordeposition (PVD) and chemical vapor deposition (CVD). The essential parametersof deposition conditions including temperature, pressure, and gas flow of bothmethods are presented. The samples were examined for their morphology by opticalmicroscopy (OM), scanning electron microscopy (SEM), atomic force microscopy(AFM), and for the crystal lattice vibration properties by Raman scattering spectrum.The results show that the single crystal flakes are located separately in hexagonal ortriangular shapes with edge lengths ranging from 20 µm to 100 µm, or can be linkedtogether to form a continuous film. The thickness of most of the film area obtainedfrom both methods can be controlled to a single layer (1L-WSe2). In addition, thephotoluminescence spectra (PL) of the samples were investigated, which indirectlyevaluated the crystallization quality of the thin films prepared from the two methods.