Engineering interlayer hybridization in van der Waals bilayers

In the decade since the introduction of van der Waals (vdW) heterostructures for designer devices, there has been an abundance of studies on the artificial assembly of vdW heterostructures for light-matter interactions, charge and energy transport, and other condensed matter phenomena. The interlayer interactions or hybridization in these systems non-trivially impact their physical characteristics and are sensitive to a complex set of interdependent, externally tunable parameters. There lacks a coherent perspective on how these external stimuli can be used together to engineer materials with desired properties. Here, we systematically address how interlayer hybridization in semiconducting vdW bilayers can be controlled for the realization of different properties in vertically stacked structures. We also discuss new research directions to engineer the interactions beyond bilayers and highlight opportunities that arise when different tuning parameters are simultaneously coupled. Interlayer hybridization in van der Waals stacks is key to understanding their physical properties. This Perspective article discusses the various parameters influencing interlayer hybridization and how they can be controlled, providing a comprehensive guide for designing materials with desired properties.