Center for Functional Nanomaterials Colloquium

Heterostructures obtained from layered assembly of 2D materials such as graphene and hexagonal boron nitride have potential in the development of new electronic devices. Whereas various materials techniques can now produce macroscopic scale graphene, the construction of similar size heterostructures with atomically clean interfaces is still unrealized. A primary barrier has been the inability to remove polymeric residues from the interfaces that arise between layers when fabricating heterostructures. In this talk, we will first introduce a polymer-assisted exfoliation technique [1] for high-yield exfoliation of large size 2D materials such as graphene and MoS2. Next, we introduce a simplified picture that describes the interface cleaning mechanism of polymer-contaminated 2D heterostructures [2]. We conclude the talk by demonstrating excellent carrier transport properties in these 2D heterostructures obtained from polymer-contaminated graphene and discussing their applications in realizing state-of-the-art gate-tunable Josephson junction devices [3,4].