Two-dimensional Czochralski growth of single-crystal MoS2

Abstract Batch production of single-crystal two-dimensional (2D) transition metal dichalcogenides is one prerequisite for the fabrication of next-generation integrated circuits (IC). Contemporary strategies for the wafer-scale high-quality crystallinity of 2D materials center on merging the unidirectionally aligned different size domains. However, the imperfectly merged area with translational lattice brings about high defect density and low device uniformity, which restricts the application of 2D materials. Here, we take the lead in establishing the 2D Czochralski method that can rapidly grow wafer-scale, single-crystal MoS₂ with no grain boundaries. The method relies on a liquid-liquid interface spreading mechanism, which eventually realizes the Czochralski method in 2D materials growth. Specifically, a 2D intermediate liquid (Na₂Mo₂O₇) film is formed through a eutectic reaction on an atomically smooth surface before sulfurization, leading to an ultralow nucleation density, an ultrafast crystallization rate (75 μm s⁻¹), and thus producing large single-crystal MoS₂ with the record domain size larger than 1.5 cm. Meanwhile, the 2D Czochralski method produces an ultra-clean, fast, and high-quality transfer process facilitated by the significantly reduced adhesion between the MoS2 crystal and the atomically smooth substrate. The obtained MoS₂ large single-crystal shows superb uniformity and high quality with an ultralow defect density of 2.9×10¹² cm⁻², a high mobility of 105.4 cm² V⁻¹ s⁻¹, and a saturation current of 443.8 μA μm⁻¹ in the short-channel devices. A statistical analysis of 192 field-effect transistors within a centimeter-scale domain showed a 96.4% device yield and a 15.9% variation in mobility with a minimal variation of 15.9%, positioning itself as an advanced standard monolayer MoS2 device. This 2D Czochralski method provides fruitful implications for fabricating high-quality and scalable 2D semiconductor materials and devices.