Residue-Free Fabrication of 2D Materials Using van der Waals Interactions

2D materials have garnered considerable attention due to their distinctive properties, prompting diverse applications across various domains. Beyond their inherent qualities, the significance of 2D materials extends into the fabrication processes that can lead to the degradation of intrinsic performance through undesirable mechanical defects and surface contaminations. Herein, a novel fabrication technique to achieve residue-free 2D materials using van der Waals (vdW) interactions, primarily employing molybdenum disulfide (MoS₂) is proposed. Optical and electrical characterizations confirm the absence of residues, mechanical defects, oxidation, and strain, along with a prominent field-effect mobility of up to 60 cm² V^-1 s^-1 and an on/off ratio of ≈10⁸. Furthermore, the utilization of residue-free material as a stamp enables various manipulations of flakes transferred on substrates in advance, including pick-up and release, stacking, exfoliation, wiping-out, flipping, and smoothing-out processes. Additionally, the manipulation techniques also facilitate the fabrication of vdW heterostructures with precise positioning and the desired stacking order. In this regard, the feasibility of applying this method to hexagonal boron nitride and graphite is demonstrated. It is expected that this method will offer a versatile and effective approach to enhancing the qualities of 2D material-based electronic and optoelectronic devices.