Stacking of Exfoliated Two-Dimensional Materials: A Review

In recent years, two-dimensional (2D) atomic crystals represented by graphene have opened up new fields of 2D physics. Layered materials with atomic layer thickness are self-assembled into van der Waals heterostructures by weak van der Waals forces without considering lattice matching. Van der Waals heterostructures can not only enhance the performance of its constituent materials but also show new characteristics. High-quality heterostructures require mechanically cleaved intrinsic 2D materials and flexible 2D material stacking techniques. Here, we summarize in detail the reliable exfoliation methods for large-area single-layer 2D materials and the dry and wet stacking techniques with high success rates. The twisted bilayer graphene is used as an example to briefly introduce the single-crystal tearing method, which is currently the most practical method for preparing isotropic twisted heterostructures with high-precision rotation angles. We hope to provide a valuable reference for researchers of 2D materials.