WS with Controllable Layer Number Grown Directly on W Film.

As a layered material with single/multi-atom thickness, two-dimensional transition metal sulfide WS has attracted extensive attention in the field of science for its excellent physical, chemical, optical, and electrical properties. The photoelectric properties of WS are even more promising than graphene. However, there are many existing preparation methods for WS, but few reports on its direct growth on tungsten films. Therefore, this paper studies its preparation method and proposes an innovative two-dimensional material preparation method to grow large-sized WS with higher quality on metal film. In this experiment, it was found that the reaction temperature could regulate the growth direction of WS. When the temperature was below 950 °C, the film showed horizontal growth, while when the temperature was above 1000 °C, the film showed vertical growth. At the same time, through Raman and band gap measurements, it is found that the different thicknesses of precursor film will lead to a difference in the number of layers of WS. The number of layers of WS can be controlled by adjusting the thickness of the precursor.