Dry Assembly of van der Waals Heterostructures Using Exfoliated and CVD-Grown 2D Materials

Van der Waals (vdW) heterostructures are stacks of two-dimensional (2D) materials that can exhibit novel physical phenomena and open a door to new device applications. A common method to create such heterostructures is the dry transfer of mechanically cleaved 2D layers, which are usually small in size and limited in material diversity. Here, we propose a simple and clean dry assembly method using polydimethylsiloxane (PDMS) to construct heterostructures based on both mechanically exfoliated and chemically vapor deposited (CVD) 2D materials. This technique allows us to combine the advantages of both types of materials, such as large size, high quality, and a wide range of properties. We demonstrate the feasibility and versatility of our method by fabricating various heterostructures with different combinations of CVD and exfoliated 2D materials, such as graphene, hexagonal boron nitride, molybdenum disulfide, and tungsten diselenide. Our method opens new possibilities for exploring the physics and applications of van der Waals heterostructures.