title: Role of hydrogen in the chemical vapor deposition growth of MoS2 atomic layers.
abstract: Hydrogen plays a crucial role in the chemical vapor deposition (CVD) growth of graphene. Here, we have revealed the roles of hydrogen in the two-step CVD growth of MoS2. Our study demonstrates that hydrogen acts as the following: (i) an inhibitor of the thermal-induced etching effect in the continuous film growth process; and (ii) a promoter of the desulfurization reaction by decreasing the S/Mo atomic ratio and the oxidation reaction of the obtained MoSx (0 < x < 2) films. A high hydrogen content of more than 100% in argon forms nano-sized circle-like defects and damages the continuity and uniformity of the film. Continuous MoS2 films with a high crystallinity and a nearly perfect S/Mo atomic ratio were finally obtained after sulfurization annealing with a hydrogen content in the range of 20%-80%. This insightful understanding reveals the crucial roles of hydrogen in the CVD growth of MoS2 and paves the way for the controllable synthesis of two-dimensional materials.
authors: School of Materials Science and Engineering, State Key Laboratory of New Ceramics and Fine Processing, Tsinghua University, Beijing 100084, China. hongweizhu@tsinghua.edu.cn.
authors: Xiao
authors: X
authors: Li
authors: Xinming
authors: X
authors: Li
authors: Xiaobei
authors: X
authors: Zang
authors: Miao
authors: M
authors: Zhu
authors: Yijia
authors: Y
authors: He
authors: Kunlin
authors: K
authors: Wang
authors: Dan
authors: D
authors: Xie
authors: Hongwei
authors: H
authors: Zhu