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Title: Electron-phonon coupling and thermal conductance at a metal-semiconductor interface: First-principles analysis

The mechanism of heat transfer and the contribution of electron-phonon coupling to thermal conductance of a metal-semiconductor interface remains unclear in the present literature. We report ab initio simulations of a technologically important titanium silicide (metal)–silicon (semiconductor) interface to estimate the Schottky barrier height, and the strength of electron-phonon and phonon-phonon heat transfer across the interface. The electron and phonon dispersion relations of TiSi{sub 2} with C49 structure and the TiSi{sub 2}-Si interface are obtained using first-principles calculations within the density functional theory framework. These are used to estimate electron-phonon linewidths and the associated Eliashberg function that quantifies coupling. We show that the coupling strength of electrons with interfacial phonon modes is of the same order of magnitude as coupling of electrons to phonon modes in the bulk metal, and its contribution to electron-phonon interfacial conductance is comparable to the harmonic phonon-phonon conductance across the interface.
Authors:
;  [1] ;  [2]
  1. Department of Mechanical Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States)
  2. Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064 (India)
Publication Date:
OSTI Identifier:
22399399
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 13; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; COMPARATIVE EVALUATIONS; COMPUTERIZED SIMULATION; DENSITY FUNCTIONAL METHOD; DIFFUSION BARRIERS; DISPERSION RELATIONS; ELECTRON-PHONON COUPLING; ELECTRONS; HEAT TRANSFER; INTERFACES; LINE WIDTHS; PHONONS; SEMICONDUCTOR MATERIALS; SILICON; THERMAL CONDUCTIVITY; TITANIUM SILICIDES