Self‐Deposition of 2D Molybdenum Sulfides on Liquid Metals

Abstract 2D transition metal dichalcogenides (TMDs) play increasingly significant roles in research and future optoelectronics. However, the large‐scale deposition of 2D TMDs remains challenging due to sparse nucleation and substrate dependency. Liquid metals can offer effective solutions to meet these challenges due to their reactive, non‐polarized, and templating properties. Here, self‐deposition of 2D molybdenum sulfide is shown by introducing a molybdenum precursor onto the surface of a eutectic alloy of gallium and indium (EGaIn). EGaIn serves as an ultra‐smooth template and reducing agent for the precursor to form large‐scale planar molybdenum sulfides, which is transferrable to any substrate. The molybdenum sulfides form spontaneously on the surface of EGaIn, which has a sufficient potential to drive the cathodic reactions of the deposition process. A highly crystalline 2H‐MoS₂ is obtained after a final annealing step. This work demonstrates a fundamentally new capability for the formation of large‐scale 2D TMDs.