Session: 11-09-01: Thermal Transport Across Interfaces I

Paper Number: 76073

Start Time: Wednesday, 10:55 AM

76073 - Modulating the Thermal Transport Across Si/4h-Sic Interface via Nanopatterns 

Manipulating the interfacial thermal transport via nanostructures is crucial for the thermal management in electronics and the energy conversion process in thermoelectric.  On one hand, higher interfacial thermal conductance will benefit the heat dissipation in electronics. On the other hand, reducing the thermal conductivity by manipulating interfacial thermal conductance can improve the heat to electricity conversion efficiency largely. Fabricating controllable nanopatterns on the interface which affect the interfacial thermal transport, has been realized recently owing to the development of the advanced manufacturing technology [1, 2]. Here, by performing nonequilibrium molecular dynamics simulations, spectral transmission coefficient and lattice dynamics analysis, we find the interfacial thermal conductance of Si/4H-SiC can be increased to around 1000 MW/m²K from 887 MW/m²K, i.e., the interfacial thermal conductance of the bare interface, and decreased to ~100 MW/m²K via interfacial nanopatterns. We also find that the interfacial thermal conductance firstly decreased then increased when the pattern size becomes larger. Such a nonmonotonic nanopattern size dependence was caused by two competing mechanisms, i.e., phonon boundary scattering and phonon transmission channel improvement. The phonons are scattered strongly by the interface while the number of phonon transmission channel is increased moderately when the area of nanopattern is smaller than 10 nm². As a result, the interfacial thermal conductance will decrease to the minimal with the increase of nanopattern area.  Meanwhile, increasing the height of the nanopattern will further decrease the interfacial thermal conductance which is resulted from the enhanced intrinsic thermal resistance of the nanopattern. Consequently, the interfacial thermal conductance of Si/4H-SiC can be reduced to around 100 MW/m²K via designing the nanopattern. On the other side, the number of phonon transmission channel will increase dramatically when the area of nanopattern is further increased, and the interfacial thermal conductance will increase to around 1000 MW/m²K for the largest system we can handle.  Further increase of the nanopattern will make the interfacial thermal conductance reach the upper limit, i.e., the enhanced interfacial thermal conductance is related to the ratio of the increased area at the certain pattern areal density.

Our work here provides the comprehensive investigation on manipulating the thermal transport across the interfaces via controllable nanopatterns, which is important and meaningful for designing and optimizing the advanced thermal interface materials.

 

 

[1] Cheng, Z., Bai, T., Shi, J., Feng, T., Wang, Y., Mecklenburg, M., Li, C., Hobart, K. D., Feygelson, T. I., Tadjer, M. J., Pate, B. B., Foley, B. M., Yates, L., Pantelides, S. T., Cola, B. A., Goorsky, M., and Graham, S., 2019, "Tunable Thermal Energy Transport across Diamond Membranes and Diamond-Si Interfaces by Nanoscale Graphoepitaxy," ACS Appl Mater Interfaces, 11(20), pp. 18517-18527.

[2] Sakata, M., Hori, T., Oyake, T., Maire, J., Nomura, M., and Shiomi, J., 2015, "Tuning thermal conductance across sintered silicon interface by local nanostructures," Nano Energy, 13, pp. 601-608.

 

Presenting Author: Yixin XU Hongkong University of Science and Technology

Authors:

Yixin XU Hongkong University of Science and Technology
Yanguang Zhou Hongkong University of Science and Technology