Thermophysical study of surface phonon polaritons in multilayer systems for heat dissipation

Heat dissipation is an important concern for micro devices which could be overheated in their working process. In the present work, aiming to find new methods for heat dissipation, the thermophysical properties induced by surface phonon polaritons in multilayer systems were probed. The specific heat capacity, expansion coefficient, thermal conductivities along in-plane and also cross-plane directions in a multilayer system which is composed of SiC films separated by vacuum gaps were all calculated and discussed. Results turn out that: The polariton-induced specific heat is much smaller than that contributed by phonons because of the large difference of the density of states. The thermal conductivity along in-plane direction could be as high as about 10(4) W m(-1) K-1 for the SiC film with a thickness of 0.1 mm, which is almost 10(12) times larger than that along cross-plane direction. This large difference of thermal conductivities suggests a potential application of the multilayer systems for heat dissipation and also a long-distance thermal energy transport. Additionally, the expansion coefficient caused by polaritons is several orders of magnitude lower than that caused by phonons, which will benefit the method by utilizing polaritons to enhance heat transfer.

Automated summary

In this study, the focus was on exploring new methods for heat dissipation in micro devices by investigating the thermophysical properties induced by surface phonon polaritons in multilayer systems. Results showed that the specific heat induced by polaritons was much smaller than that contributed by phonons, while the thermal conductivity along the in-plane direction could be significantly higher, suggesting potential applications in heat dissipation and long-distance thermal energy transport. The expansion coefficient caused by polaritons was also found to be much lower than that caused by phonons, which could benefit the enhancement of heat transfer using polaritons.