CAREER: Prediction and understanding of thermal transport across successive interfaces

University Of Utah, Salt Lake City UT

Investigators

Abstract

Many cutting-edge applications require heat flow management across successive layers of materials. For example, in the power electronics and radiofrequency electronics used in radars, 5G stations, satellite communications, adapters, inverters, and chargers, the extensive heat generated in the modules needs to be dissipated rapidly through multiple layers of semiconductors in the transistors. In the thermal barrier coatings, hypersonic aircraft thermal protection, and thermoelectrics, the extensive heat needs to be blocked by several layers of different materials. However, heat transport through successive layers and interfaces has not been well understood, impeding the rational design of next-generation chips, electronics, engines, hypersonic vehicles, and other applications. Therefore, the principal aim of this project is to provide an accurate prediction and a deep understanding of thermal transport across successive layers and interfaces of different materials. The project will also encompass significant educational activities, including hands-on science kits and lectures for K-12 students in various local communities, online videos for kids, research internship opportunities for high school students, and a free online graduate course. The goal of this project is to establish a comprehensive understanding of phonon thermal transport across two or more successive solid interfaces, build a formalism and a simulation framework for successive interfacial thermal transport, accurately predict the thermal transport across several technologically important wide-bandgap semiconductor heterostructures, and enhance modern science and engineering education from kindergarten to graduate levels using diverse methods. The project will (1) establish high-accuracy machine learning interatomic potential-based molecular dynamics simulations for successive interfacial thermal transport predictions; (2) develop new Landauer’s formalisms capable of double and multiple interfacial thermal transport; (3) develop a new phonon Boltzmann transport framework for successive interfacial thermal transport; and (4) reveal how the interfacial thermal conductance, thermal conductivity, mode-resolved phonon transmission, reflection, temperature, and heat flux are affected by (i) the presence of and distance from a second interface, (ii) the roughness of the interfaces, (iii) the materials comprising the interfaces, (iv) the phonon excitations in the external heat source, (v) the conditions far from the interface such as the impurities inside the film and the roughness of edges, and (vi) the presence of more interfaces. The results will be integrated into educational programs to enhance learning from kindergarten to graduate levels. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.