Large-Domain Monolayer MoS₂ Synthesis via Local-Feeding Metalorganic Chemical Vapor Deposition

Abstract

Two-dimensional (2D) transition metal dichalcogenides (TMDs) such as MoS2, capable of forming stable monolayers that are only three-atoms thick, have exhibited remarkable properties for next-generation electronic and optoelectronic applications. The realization of these 2D material-based technologies requires the development of scalable synthesis methods, among which metalorganic chemical vapor deposition (MOCVD) has emerged as a viable route. Nevertheless, current MOCVD processes confront challenges associated with small domain sizes typically in the submicrometer range, leading to dense grain boundary defects that compromise the crystal quality of the MoS2 films. We herein present the MOCVD growth of large-size and single-crystal MoS2 monolayers using a quartz nozzle-guided precursor delivery approach. This growth method substantially reduces the nucleation density, enabling the formation of record-large MoS2 crystals (>300 μm) among all MOCVD results. Our work demonstrates that large-domain growth is compatible with the high-reactivity metalorganic precursors, on the condition that the growth dynamics are deliberately engineered.