Recent Advances in Synthesis and Assembly of van der Waals Materials

After the discovery of graphene, other two-dimensional (2D) layered crystals have attracted extensive attention because of their fundamental physical properties. Semiconducting 2D solids, such as transition metal dichalcogenides (TMDCs), has superior benefits in terms of the ultra-thin body, high mechanical strength, and thermal stability. Most importantly, a new material platform could overcome the performance of graphene with a sizable electronic gap. As expected, the materials have a variety of device applications. Atomically thin TMDC layer preparation and assembly have been combined for generating a van der Waals layered material due to lack of robust techniques for epitaxial growth. In spite of significant research efforts on material growth, large-scale growth with defect-free film quality remains a challenge. Here, we provide an overview of the traditional approach and recent progress in top-down methods such as vapor phase growth and solution processes. Layer-by-layer stacking of diverse material toward the realization of complex heterostructured devices is discussed. State-of-the-art assembling techniques with alternative methods are described.