Thermal conductivity assessment in a low dimension structure

Abstract

The thermal conductivity of low dimensional structures remains critical for various applications. These structures can be formed from various thin films. and proper assessment of effective thermal conductivity becomes vital for the stable operation of such structures. Effective thermal conductivity of low dimension structure composing of silicon‑aluminum films is examined incorporating the thermal resistances generated in the structure. Frequency-depended phonon transfer in the structure is considered, and equivalent equilibrium temperature is adopted representing the phonon intensity. Thermal boundary resistance, resistance due to phonon scattering, and interfacial resistance are incorporated to evaluate the overall thermal resistance in the structure. The effective thermal conductivity predicted for the silicon film is compared to that of the results of the early formulation. The findings show that thermal conductivity predictions for the silicon film are in agreement with that presented in the early formulation. The slight differences in both results are because of the contribution of the ballistic phonons to thermal resistance. In addition, enlarging the silicon film thickness in the structure increases the thermal conductivity.