A new regime of nanoscale thermal transport: Collective diffusion increases dissipation efficiency
| Autor: | Henry C. Kapteyn, Kathleen Hoogeboom-Pot, Travis Frazer, Jorge N. Hernandez-Charpak, Weilun Chao, Margaret M. Murnane, Erik H. Anderson, Ronggui Yang, Xiaokun Gu, Roger Falcone, Damiano Nardi |
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| Rok vydání: | 2015 |
| Předmět: |
Condensed Matter - Materials Science
Work (thermodynamics) Multidisciplinary Materials science Condensed Matter - Mesoscale and Nanoscale Physics Condensed matter physics Mean free path Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences Mechanical engineering Dissipation mean free path spectroscopy ultrafast X-rays Thermal conduction nanoscale thermal transport high harmonic generation Thermal conductivity Affordable and Clean Energy nondiffusive transport Thermal radiation Mesoscale and Nanoscale Physics (cond-mat.mes-hall) Physical Sciences Heat transfer Thermoelectric effect |
| Zdroj: | Proceedings of the National Academy of Sciences of the United States of America, vol 112, iss 16 |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.1503449112 |
| Popis: | Understanding thermal transport from nanoscale heat sources is important for a fundamental description of energy flow in materials, as well as for many technological applications including thermal management in nanoelectronics, thermoelectric devices, nano-enhanced photovoltaics and nanoparticle-mediated thermal therapies. Thermal transport at the nanoscale is fundamentally different from that at the macroscale and is determined by the distribution of carrier mean free paths in a material, the length scales of the heat sources, and the distance over which heat is transported. Past work has shown that Fourier's law for heat conduction dramatically over-predicts the rate of heat dissipation from heat sources with dimensions smaller than the mean free path of the dominant heat-carrying phonons. In this work, we uncover a new regime of nanoscale thermal transport that dominates when the separation between nanoscale heat sources is small compared with the dominant phonon mean free paths. Surprisingly, the interplay between neighboring heat sources can facilitate efficient, diffusive-like heat dissipation, even from the smallest nanoscale heat sources. This finding suggests that thermal management in nanoscale systems including integrated circuits might not be as challenging as projected. Finally, we demonstrate a unique and new capability to extract mean free path distributions of phonons in materials, allowing the first experimental validation of differential conductivity predictions from first-principles calculations. Main text: 18 pages, 4 figures. Supplementary Information: 13 pages, 9 figures |
| Databáze: | OpenAIRE |
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