Robust growth of two-dimensional metal dichalcogenides and their alloys by active chalcogen monomer supply.

Zuo, Yonggang; Liu, Can; Ding, Liping; Qiao, Ruixi; Tian, Jinpeng; Liu, Chang; Wang, Qinghe; Xue, Guodong et al. · Nat Commun · 2022

basic_science · Level V

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Abstract

The precise precursor supply is a precondition for controllable growth of two-dimensional (2D) transition metal dichalcogenides (TMDs). Although great efforts have been devoted to modulating the transition metal supply, few effective methods of chalcogen feeding control were developed. Here we report a strategy of using active chalcogen monomer supply to grow high-quality TMDs in a robust and controllable manner, e.g., MoS<sub>2</sub> monolayers perform representative photoluminescent circular helicity of ~92% and electronic mobility of ~42 cm<sup>2</sup>V<sup>-1</sup>s<sup>-1</sup>. Meanwhile, a uniform quaternary TMD alloy with three different anions, i.e., MoS<sub>2(1-x-y)</sub>Se<sub>2x</sub>Te<sub>2y</sub>, was accomplished. Our mechanism study revealed that the active chalcogen monomers can bind and diffuse freely on a TMD surface, which enables the effective nucleation, reaction, vacancy healing and alloy formation during the growth. Our work offers a degree of freedom for the controllable synthesis of 2D compounds and their alloys, benefiting the development of high-end devices with desired 2D materials.