Adhesion and Self-Healing between Monolayer Molybdenum Disulfide and Silicon Oxide

The adhesion interactions of two-dimensional (2D) materials are of importance in developing flexible electronic devices due to relatively large surface forces. Here, we investigated the adhesion properties of large-area monolayer MoS₂ grown on silicon oxide by using chemical vapor deposition. Fracture mechanics concepts using double cantilever beam configuration were used to characterize the adhesion interaction between MoS₂ and silicon oxide. While the interface between MoS₂ and silicon oxide was fractured under displacement control, force-displacement response was recorded. The separation energy, adhesion strength and range of the interactions between MoS₂ and silicon oxide were characterized by analytical and numerical analyses. In addition to the fundamental adhesion properties of MoS₂, we found that MoS₂ monolayers on silicon oxide had self-healing properties, meaning that when the separated MoS₂ and silicon oxide were brought into contact, the interface healed. The self-healing property of MoS₂ is potentially applicable to the development of new composites or devices using 2D materials.