Universal Transfer and Stacking of Chemical Vapor Deposition Grown Two-Dimensional Atomic Layers with Water-Soluble Polymer Mediator.

Chemical vapor deposition (CVD) has shown great potential in synthesizing various high-quality two-dimensional (2D) transition metal dichalcogenides (TMDCs). However, the nondestruction transfer of these CVD-grown 2D TMDCs at a high yield remains a key challenge for applying these emerging materials in various aspects. To address this challenge, we designed a water-soluble transfer mediator consisting of two polymers, polyvinylpyrrolidone (PVP) and poly(vinyl alcohol) (PVA), which can form strong interactions with CVD-grown 2D TMDCs for the nondestruction transfer of these materials. With this mediator, we realized the physical transfer of CVD-grown MoS2 flakes and several other 2D TMDCs, including 2D alloys and heterostructures to a wide range of substrates at a high yield of >90% with well-retained properties as evidenced by various microscopic, spectroscopic, and electrical measurements. Field-effect transistors (FETs) made on thus-transferred CVD-grown MoS2 monolayers exhibited obviously higher mobility than those transferred by chemical method. We also constructed several artificial 2D crystals showing very strong interlayer coupling by the multiple transfer of CVD-grown 2D TMDCs monolayers with this approach. This transfer approach will make versatile CVD-grown 2D materials and their artificial stacks with pristine qualities easily accessible for both fundamental studies and practical applications.