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

Yonggang Zuo,Kaihui Liu,Feng Ding,Jinpeng Tian,Hao Hong,Yilong You,Enge Wang,Chang Liu,Kehai Liu,Xiaobo Lu,Liping Ding,Xumin Zhou ,Rong Yang,Qinghe Wang,Jinhuan Wang,Guodong Xue,Ruixi Qiao,Dapeng Yu,Guangyu Zhang,Can Liu,Muhong Wu,Quanlin Guo,Ying Fu,Xuedong Bai

doi:10.1038/s41467-022-28628-7

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., MoS2 monolayers perform representative photoluminescent circular helicity of ~92% and electronic mobility of ~42 cm2V−1s−1. Meanwhile, a uniform quaternary TMD alloy with three different anions, i.e., MoS2(1-x-y)Se2xTe2y, 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.

Highlights

2, Dapeng Yu10, The precise precursor supply is a precondition for controllable growth of two-dimensional (2D) transition metal dichalcogenides (TMDs)
For the growth of 2D materials, the as-grown graphene already has excellent properties, which is comparable to the samples exfoliated from natural crystals, and the measured carrier mobilities are close to the theoretical limit[15], while the as-grown 2D compounds of TMDs, typically have lower quality than the natural crystals or the theoretical expectations[16]
Developing more effective chalcogen supply methods to enable the growth of TMDs with high quality and rich composition is of critical importance

Summary

Introduction

2, Dapeng Yu10, The precise precursor supply is a precondition for controllable growth of two-dimensional (2D) transition metal dichalcogenides (TMDs). The synthesis of high-quality TMD materials requires the precise feeding control of both the transition metal and chalcogen precursors. The slowly released chalcogen monomers have a very low probability to react with each other to form dimers, enable the successful synthesis of TMDs (MX2, M = Mo, W; X = S, Se, Te) and their alloys with very high quality.

Results

Conclusion