Size and interface effects on thermal conductivity of superlattices and periodic thin-film structures
- Duke Univ., Durham, NC (United States). Dept. of Mechanical Engineering and Materials Science
Superlattices consisting of alternating layers of extremely thin films often demonstrate strong quantum size effects, which have been utilized to improve conventional devices and develop new ones. The interfaces in these structures also affect their thermophysical properties through reflection and transmission of heat carriers. This work develops models on the effective thermal conductivity of periodic thin-film structures in the parallel direction based on the Boltzmann transport equation. Different interface conditions including specular, diffuse, and partially specular and partially diffuse interfaces, are considered. Predictions obtained from the diffuse interface scattering model are in reasonable agreement with experimental results on GaAs/AlAs superlattices. The study suggests that interface roughness is the major cause for the measured reduction in the superlattice thermal conductivity. Results of this work are also applicable to other periodic structures used in optical coatings and optoelectronic devices.
- Sponsoring Organization:
- National Science Foundation, Washington, DC (United States)
- OSTI ID:
- 428095
- Report Number(s):
- CONF-960815--; ISBN 0-7918-1505-6
- Country of Publication:
- United States
- Language:
- English
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