Oxygen-Mediated Precursor Pretreatment for Controllable Growth of Centimeter-Scale Monolayer Transition Metal Dichalcogenides

Two-dimensional transition metal dichalcogenides (TMDCs) are promising for post-Moore electronics owing to their unique properties. Mechanical exfoliation is the primary method for high-quality TMDCs but suffers from low yield, size limits, and randomness. Physical vapor deposition (PVD) enables scalable production yet struggles with multielement TMDCs deposition; mismatched evaporation rates and insufficient selenide precursor vapor pressure impair film uniformity and grain growth. Here, we develop an innovative oxygen-doped precursor pretreatment coupled with a reverse-flow reactor design to address these issues. This method boosts precursor volatility, stabilizes vapor composition, and achieves uniform, rapid growth of centimeter-scale, high-crystallinity monolayer TMDCs films (MoSe₂, MoS₂, WSe₂, WS₂). The films show high carrier mobility (45.065 cm²/V·s for MoSe₂) and broadband photoresponse (405-850 nm), demonstrating excellent electrical and optical performance. This work provides a scalable strategy for high-performance TMDCs and new insights into resolving PVD challenges and promotes 2D materials integration into practical devices.