Site-Specific Positioning and Patterning of MoS2 Monolayers: The Role of Au Seeding

摘要

Monolayers of transition metal dichalcogenides (TMDs) are attractive for various modern semiconductor devices. However, the limited control over the location, yield, and size distribution of the products using current synthesis methods has severely limited their large-scale applicability. Herein, we identify the ability to use metal (e.g., Au) nanoparticles to seed the growth of MoS2 monolayers and thereby provide a means to achieve programmable and controllable synthesis. In this study, prepatterned Au seeds are used as heterogeneous nucleation sites to induce the formation of desired geometries of MoS2 monolayers via chemical vapor deposition. Our experimental and theoretical results shed light on the growth mechanism driving the formation of MoS2 monolayers at these sites, revealing that the seeding effect originates from the favorable formation energy of MoS2 on the Au surface. A field-effect transistor with a predesigned channel geometry exhibits electronic performance that compares nicely with previously reported MoS2 monolayer devices. We believe this study contributes fundamental insights into controlled synthesis of TMD monolayers, making integration of these materials into emerging electronic devices more attainable.