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Title: Role of direct electron-phonon coupling across metal-semiconductor interfaces in thermal transport via molecular dynamics

Abstract

Motivated by significant interest in metal-semiconductor and metal-insulator interfaces and superlattices for energy conversion applications, we developed a molecular dynamics-based model that captures the thermal transport role of conduction electrons in metals and heat transport across these types of interface. Key features of our model, denoted eleDID (electronic version of dynamics with implicit degrees of freedom), are the natural description of interfaces and free surfaces and the ability to control the spatial extent of electron-phonon (e-ph) coupling. Non-local e-ph coupling enables the energy of conduction electrons to be transferred directly to the semiconductor/insulator phonons (as opposed to having to first couple to the phonons in the metal). We characterize the effect of the spatial e-ph coupling range on interface resistance by simulating heat transport through a metal-semiconductor interface to mimic the conditions of ultrafast laser heating experiments. Direct energy transfer from the conduction electrons to the semiconductor phonons not only decreases interfacial resistance but also increases the ballistic transport behavior in the semiconductor layer. These results provide new insight for experiments designed to characterize e-ph coupling and thermal transport at the metal-semiconductor/insulator interfaces.

Authors:
;  [1]
  1. School of Materials Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States)
Publication Date:
OSTI Identifier:
22490922
Resource Type:
Journal Article
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 143; Journal Issue: 3; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-9606
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CONTROL; DEGREES OF FREEDOM; ELECTRON-PHONON COUPLING; ELECTRONS; ENERGY CONVERSION; INTERFACES; LASER-RADIATION HEATING; LAYERS; METALS; MOLECULAR DYNAMICS METHOD; PHONONS; SEMICONDUCTOR MATERIALS; SUPERLATTICES; SURFACES

Citation Formats

Lin, Keng-Hua, and Strachan, Alejandro. Role of direct electron-phonon coupling across metal-semiconductor interfaces in thermal transport via molecular dynamics. United States: N. p., 2015. Web. doi:10.1063/1.4922893.
Lin, Keng-Hua, & Strachan, Alejandro. Role of direct electron-phonon coupling across metal-semiconductor interfaces in thermal transport via molecular dynamics. United States. https://doi.org/10.1063/1.4922893
Lin, Keng-Hua, and Strachan, Alejandro. Tue . "Role of direct electron-phonon coupling across metal-semiconductor interfaces in thermal transport via molecular dynamics". United States. https://doi.org/10.1063/1.4922893.
@article{osti_22490922,
title = {Role of direct electron-phonon coupling across metal-semiconductor interfaces in thermal transport via molecular dynamics},
author = {Lin, Keng-Hua and Strachan, Alejandro},
abstractNote = {Motivated by significant interest in metal-semiconductor and metal-insulator interfaces and superlattices for energy conversion applications, we developed a molecular dynamics-based model that captures the thermal transport role of conduction electrons in metals and heat transport across these types of interface. Key features of our model, denoted eleDID (electronic version of dynamics with implicit degrees of freedom), are the natural description of interfaces and free surfaces and the ability to control the spatial extent of electron-phonon (e-ph) coupling. Non-local e-ph coupling enables the energy of conduction electrons to be transferred directly to the semiconductor/insulator phonons (as opposed to having to first couple to the phonons in the metal). We characterize the effect of the spatial e-ph coupling range on interface resistance by simulating heat transport through a metal-semiconductor interface to mimic the conditions of ultrafast laser heating experiments. Direct energy transfer from the conduction electrons to the semiconductor phonons not only decreases interfacial resistance but also increases the ballistic transport behavior in the semiconductor layer. These results provide new insight for experiments designed to characterize e-ph coupling and thermal transport at the metal-semiconductor/insulator interfaces.},
doi = {10.1063/1.4922893},
url = {https://www.osti.gov/biblio/22490922}, journal = {Journal of Chemical Physics},
issn = {0021-9606},
number = 3,
volume = 143,
place = {United States},
year = {2015},
month = {7}
}