Synthesis of centimeter-scale WS2 membrane by chemical vapor deposition.

Transition metal dichalcogenides (TMDCs) are among the most widely studied two-dimensional materials due to their unique physical properties, but synthesis of large area of monolayer TMDCs films is still a great challenge. In this study, a simple and universal promoter-assisted chemical vapor deposition (CVD) method is proposed for the synthesis of centimeter-scale of Tungsten disulfide (WS₂) membranes. The highly volatile transition metal halides formed by the reaction of Tungstic acid (H₂WO₄) and Sodium chloride (NaCl) effectively reduces the growth temperature of WS₂, and the vulcanization energy barrier for the growth of WS₂ monolayer, thus improve the growth rate along the in-plane direction. By optimizing the experimental parameters, high quality of WS₂ films in centimeter-sizes are prepared. This study provides a method for the preparation of large-scale WS₂ films and lays a foundation for the industrial application of large-scale two-dimensional materials. [ABSTRACT FROM AUTHOR]