Space-confined and uniform growth of 2D MoS2 flakes.

As an important next-generation photoelectric material, the controlled synthesis of two-dimensional molybdenum disulfide (2D MoS 2) with high uniformity is imperative. Traditional MoS 2 growth methods in the open space usually require a large amount of raw materials and have poor uniformity of growth results. In this paper, we report a space-confined method for uniformly growing large MoS 2 flakes on the SiO 2 /Si substrate. As the precursor film coated on the bottom substrate is restricted in a small confined space between the top and bottom substrates separated by a small spacer, it is efficiently utilized, achieving large MoS 2 flakes with good uniformity on the top substrate. By further tuning the content of NaCl catalyst in the precursor, single-layer or multi-layer MoS 2 flakes can be obtained in a controlled manner, and well characterized by Raman, XPS, PL and AFM. The uniform distribution of Mo-containing species and its high concentration in the confined space, contributing to the efficient growth of uniform large MoS 2 flakes. This research will provide guidance for rational synthesis of 2D MoS 2 flakes on dielectric substrates. A space-confined method is proposed to grow large MoS 2 flakes uniformly and efficiently on the SiO 2 /Si substrate. [Display omitted] • A space-confined method for growing large MoS 2 flakes uniformly and efficiently on the SiO 2 /Si substrate is proposed. • This method is featured with ultralow precursor consumption and high growth uniformity of MoS 2 flakes. • Monolayer or multilayer MoS 2 flakes can be obtained in a controlled manner by adjusting the content of NaCl catalyst. [ABSTRACT FROM AUTHOR]