Optimizing Large-Area Growth of MoS2Using Advanced Precursor Engineering: A Pathway to Scalable and High-Quality Synthesis

Abstract

The chemical vapor deposition (CVD) for the growth of transition-metal dichalcogenides (TMDs) remains a significant focus of research due to the critical need for producing high-quality films on a large scale for various applications. The selection of starting materials for Mo and S sources plays a critical role in determining the layers and morphologies of MoS<inf>2</inf> films. Different sources influence these aspects differently. Traditionally, most studies have relied on commercially available MoO<inf>3</inf> powder and elemental sulfur, which often require high reaction temperatures and yield low efficiencies. In this research, MoS<inf>2</inf> was synthesized using the CVD method, and its structural properties were analyzed by varying the growth temperature and precursors. Notably, synthesized h-MoO<inf>3</inf> outperformed its commercial counterpart. Additionally, a novel precursor, Na<inf>2</inf>MoO<inf>4</inf>, was designed and used as a Mo source for the growth of MoS<inf>2</inf>. The findings revealed the successful synthesis of both monolayer triangular crystals and continuous 2D MoS<inf>2</inf> films. The triangular 2D crystals, synthesized using h-MoO<inf>3</inf>, had an average size of 30–50 μm and a monolayer thickness of approximately 0.9 nm. When α-Na<inf>2</inf>MoO<inf>4</inf> was employed as the Mo precursor, a continuous 2D film with a lateral size extending to the centimeter scale was achieved. Additionally, a model explaining the growth mechanism capable of producing TMD monolayers was proposed. © 2025 American Chemical Society