Experimental observation of localized interfacial phonon modes.

Autor: Cheng Z; George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA.; Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA., Li R; Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, IN, 46556, USA., Yan X; Department of Materials Science and Engineering, University of California, Irvine, CA, 92697, USA.; Irvine Materials Research Institute, University of California, Irvine, CA, 92697, USA., Jernigan G; U.S. Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, DC, 20375, USA., Shi J; George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA., Liao ME; Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA., Hines NJ; George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA., Gadre CA; Department of Physics and Astronomy, University of California, Irvine, CA, 92617, USA., Idrobo JC; Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA., Lee E; Department of Electronic Engineering, Kyung Hee University, Yongin-si, Gyeonggi-do, 17104, South Korea., Hobart KD; U.S. Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, DC, 20375, USA., Goorsky MS; Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA., Pan X; Department of Materials Science and Engineering, University of California, Irvine, CA, 92697, USA. xiaoqinp@uci.edu.; Irvine Materials Research Institute, University of California, Irvine, CA, 92697, USA. xiaoqinp@uci.edu.; Department of Physics and Astronomy, University of California, Irvine, CA, 92617, USA. xiaoqinp@uci.edu., Luo T; Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, IN, 46556, USA. tluo@nd.edu., Graham S; George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA. sgraham@gatech.edu.
Jazyk: angličtina
Zdroj: Nature communications [Nat Commun] 2021 Nov 25; Vol. 12 (1), pp. 6901. Date of Electronic Publication: 2021 Nov 25.
DOI: 10.1038/s41467-021-27250-3
Abstrakt: Interfaces impede heat flow in micro/nanostructured systems. Conventional theories for interfacial thermal transport were derived based on bulk phonon properties of the materials making up the interface without explicitly considering the atomistic interfacial details, which are found critical to correctly describing thermal boundary conductance. Recent theoretical studies predicted the existence of localized phonon modes at the interface which can play an important role in understanding interfacial thermal transport. However, experimental validation is still lacking. Through a combination of Raman spectroscopy and high-energy-resolution electron energy-loss spectroscopy in a scanning transmission electron microscope, we report the experimental observation of localized interfacial phonon modes at ~12 THz at a high-quality epitaxial Si-Ge interface. These modes are further confirmed using molecular dynamics simulations with a high-fidelity neural network interatomic potential, which also yield thermal boundary conductance agreeing well with that measured in time-domain thermoreflectance experiments. Simulations find that the interfacial phonon modes have an obvious contribution to the total thermal boundary conductance. Our findings significantly contribute to the understanding of interfacial thermal transport physics and have impact on engineering thermal boundary conductance at interfaces in applications such as electronics thermal management and thermoelectric energy conversion.
(© 2021. The Author(s).)
Databáze: MEDLINE
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