Monolayer MoS2 growth at the Au–SiO2 interface

Atomically thin transition-metal dichalcogenides (TMDs) are attracting great interest for future electronic applications. Even though much effort has been devoted to preparing large-area, high-quality TMDs over the past few years, the samples are usually grown on substrate surfaces. Here, we demonstrate the direct growth of a MoS2 monolayer at the interface between a Au film and a SiO2 substrate. MoS2 grains were nucleated below Au films deposited on SiO2 via interface diffusion and then grown into a continuous MoS2 film. By programming the Au pattern deposited, controlled growth of MoS2 with the desired size and geometry was achieved over preferred locations, facilitating its integration into functional field-effect transistors. Our findings elucidate the fabrication of a two-dimensional semiconductor at the interface of bulk three-dimensional solids, providing a novel means for establishing a clean interface junction. It also offers a promising alternative to the site-selective synthesis of TMDs, which is expected to aid the fabrication of TMD-based nanodevices.