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Title: Electron-phonon interaction and thermal boundary resistance at the crystal-amorphous interface of the phase change compound GeTe

Phonon dispersion relations and electron-phonon coupling of hole-doped trigonal GeTe have been computed by density functional perturbation theory. This compound is a prototypical phase change material of interest for applications in phase change non-volatile memories. The calculations allowed us to estimate the electron-phonon contribution to the thermal boundary resistance at the interface between the crystalline and amorphous phases present in the device. The lattice contribution to the thermal boundary resistance has been computed by non-equilibrium molecular dynamics simulations with an interatomic potential based on a neural network scheme. We find that the electron-phonon term contributes to the thermal boundary resistance to an extent which is strongly dependent on the concentration and mobility of the holes. Further, for measured values of the holes concentration and electrical conductivity, the electron-phonon term is larger than the contribution from the lattice. It is also shown that the presence of Ge vacancies, responsible for the p-type degenerate character of the semiconductor, strongly affects the lattice thermal conductivity of the crystal.
Authors:
;  [1] ;  [2] ;  [3] ;  [4]
  1. Dipartimento di Scienza dei Materiali, Università di Milano-Bicocca, Via R. Cozzi 55, I-20125, Milano (Italy)
  2. Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz (Germany)
  3. Computational Science, Department of Chemistry and Applied Biosciences, ETH Zurich, USI Campus, via Giuseppe Buffi 13, CH-6900 Lugano (Switzerland)
  4. Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, Universitätsstrasse 150, D-44780 Bochum (Germany)
Publication Date:
OSTI Identifier:
22399234
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 1; 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; AMORPHOUS STATE; COMPUTERIZED SIMULATION; CONCENTRATION RATIO; CRYSTALS; DENSITY FUNCTIONAL METHOD; DISPERSION RELATIONS; DOPED MATERIALS; ELECTRIC CONDUCTIVITY; ELECTRON-PHONON COUPLING; ELECTRONS; GERMANIUM TELLURIDES; HOLES; INTERFACES; MOLECULAR DYNAMICS METHOD; PHASE CHANGE MATERIALS; PHONONS; SEMICONDUCTOR MATERIALS; THERMAL BOUNDARY RESISTANCE; THERMAL CONDUCTIVITY; VACANCIES