Acoustic Mismatch Model for Thermal Contact Conductance of Van Der Waals Contacts Under Static Force

Van der Waals interfaces play a major role in technology today. Thermal transport in material systems with van der Waals interfaces is mainly limited by the contact conductance. Although the effects of static force, such as pressure or the electrostatic part of hydrogen bonds, on the thermal contact conductance of van der Waals interfaces have been examined in a few studies, the focus was either on numerical simulation using techniques such as molecular dynamics or on experimental investigation. In this article, an analytical model of thermal contact conductance that accounts for the effects of static force and adhesion energy is presented. The application of static forces is found to cause a decrease in the intermolecular distance, which leads to increased interatomic forces across the interfaces and thus higher thermal conductance. The model is in good agreement with experimental data on the effect of pressure on thermal conductance collected by Gotsmann and Lantz (Nature Materials, Vol. 12, p. 59–65, 2012).