title: Ultrafast Self-Limited Growth of Strictly Monolayer WSe2Crystals.
abstract: The controllable synthesis of uniform tungsten diselenide (WSe2) is crucial for its emerging applications due to the high sensitivity of its extraordinary physicochemical properties to its layer numbers. However, undesirable multilayer regions inevitably form during the fabrication of WSe2via the traditional chemical vapor deposition process resulted from the lack of significantly energetically favorable competition between layer accumulation and size expansion. This work innovatively introduces Cu to occupy the hexagonal site positioned at the center of the six membered ring of the WSe2surface, thus filtrates the undesired reaction path through precisely thermodynamical control and achieves self-limited growth WSe2crystals. The as-obtained WSe2crystals are characterized as strictly single-layer over the entire wafer. Furthermore, the strictly self-limited growth behavior can achieve the "win-win" cooperation with the synthesis efficiency. The fastest growth (≈15 times of the growth rate in the previous work) of strictly monolayer WSe2crystals thus far is realized due to the high-efficiency simultaneous selenization process. The as-proposed ultrafast Cu-assisted self-limited growth method opens a new avenue to fabricate strictly monolayer transition metal dichalcogenides crystals and further promotes their practical applications in the future industrial applications.
authors: College of Chemistry and Molecular Science, Wuhan University, Wuhan, 430072, China.
authors: Jinxin
authors: J
authors: Liu
authors: College of Chemistry and Molecular Science, Wuhan University, Wuhan, 430072, China.
authors: Mengqi
authors: M
authors: Zeng
authors: College of Chemistry and Molecular Science, Wuhan University, Wuhan, 430072, China.
authors: Lingxiang
authors: L
authors: Wang
authors: College of Chemistry and Molecular Science, Wuhan University, Wuhan, 430072, China.
authors: Yongting
authors: Y
authors: Chen
authors: School of Physics and Technology, Wuhan University, Wuhan, 430072, China.
authors: Zhuo
authors: Z
authors: Xing
authors: College of Chemistry and Molecular Science, Wuhan University, Wuhan, 430072, China.
authors: Tao
authors: T
authors: Zhang
authors: College of Chemistry and Molecular Science, Wuhan University, Wuhan, 430072, China.
authors: Zheng
authors: Z
authors: Liu
authors: College of Chemistry and Molecular Science, Wuhan University, Wuhan, 430072, China.
authors: Junlai
authors: J
authors: Zuo
authors: School of Physics and Technology, Wuhan University, Wuhan, 430072, China.
authors: Fan
authors: F
authors: Nan
authors: IFW Dresden, P.O. Box 270116, Dresden, 01069, Germany.
authors: Rafael G
authors: RG
authors: Mendes
authors: College of Chemistry and Molecular Science, Wuhan University, Wuhan, 430072, China.
authors: Shengli
authors: S
authors: Chen
authors: School of Physics and Technology, Wuhan University, Wuhan, 430072, China.
authors: Feng
authors: F
authors: Ren
authors: School of Physics and Technology, Wuhan University, Wuhan, 430072, China.
authors: Ququan
authors: Q
authors: Wang
authors: IFW Dresden, P.O. Box 270116, Dresden, 01069, Germany.
authors: Mark H
authors: MH
authors: Rümmeli
authors: College of Chemistry and Molecular Science, Wuhan University, Wuhan, 430072, China. leifu@whu.edu.cn.
authors: Lei
authors: L
authors: Fu
keywords: Cu-occupation; WSe2 crystals; self-limited; strictly monolayer; ultrafast