Substrate contribution to van der Waals interaction on surface of monolayer boron nitride

Interfacial van der Waals interactions are ubiquitous and play pivotal roles in diverse fields, ranging from microelectromechanical systems to atomic manufacturing. Clarifying its penetration depth and sub-surface contributions is crucial for revealing the structure–property relationship and its potential on-demand design. Taking inert monolayer boron nitride as a model system, we demonstrated that substrate notably contribute to its van der Waals adhesion with objects in contact with it. Atomic force microscopy spectrum and density functional theory calculations consistently indicate that the critical adhesion pressure exerted on the tip by copper-supported monolayer BN is stronger than that by bulk BN. Decoupling BN from copper through oxygen intercalation results in a notable reduction in surface adhesion. These results shed light on ways to modulating interfacial van der Waals interactions.