Highly Reproducible Epitaxial Growth of Wafer‐Scale Single‐Crystal Monolayer MoS₂ on Sapphire

Abstract 2D semiconducting transition‐metal dichalcogenides (TMDs) have attracted considerable attention as channel materials for next‐generation transistors. To meet the industry needs, large‐scale production of single‐crystal monolayer TMDs in highly reproducible and energy‐efficient manner is critically significant. Herein, it is reported that the high‐reproducible, high‐efficient epitaxial growth of wafer‐scale monolayer MoS 2 single crystals on the industry‐compatible sapphire substrates, by virtue of a deliberately designed “face‐to‐face” metal‐foil‐based precursor supply route, carbon‐cloth‐filter based precursor concentration decay strategy, and the precise optimization of the chalcogenides and metal precursor ratio (i.e., S/Mo ratio). This unique growth design can concurrently guarantee the uniform release, short‐distance transport, and moderate deposition of metal precursor on a wafer‐scale substrate, affording high‐efficient and high‐reproducible growth of wafer‐scale single crystals (over two inches, six times faster than usual). Moreover, the S/Mo precursor ratio is found as a key factor for the epitaxial growth of MoS 2 single crystals with rather high crystal quality, as convinced by the relatively high electronic performances of related devices. This work demonstrates a reliable route for the batch production of wafer‐scale single‐crystal 2D materials, thus propelling their practical applications in highly integrated high‐performance nanoelectronics and optoelectronics.