Ab initio calculation of electron–phonon coupling in monoclinic βGa{sub 2}O{sub 3} crystal
Abstract
The interaction between electrons and vibrational modes in monoclinic βGa{sub 2}O{sub 3} is theoretically investigated using abinitio calculations. The large primitive cell of βGa{sub 2}O{sub 3} gives rise to 30 phonon modes all of which are taken into account in transport calculation. The electronphonon interaction is calculated under density functional perturbation theory and then interpolated using Wannier–Fourier interpolation. The longrange interaction elements between electrons and polar optical phonon (POP) modes are calculated separately using the Born effective charge tensor. The direction dependence of the longrange POP coupling in a monoclinic crystal is explored and is included in the transport calculations. Scattering rate calculations are done using the Fermi golden rule followed by solving the Boltzmann transport equation using the Rode's method to estimate low field mobility. A room temperature mobility of 115 cm{sup 2}/V s is observed. Comparison with recent experimentally reported mobility is done for a wide range of temperatures (30 K–650 K). It is also found that the POP interaction dominates the electron mobility under low electric field conditions. The relative contribution of the different POP modes is analyzed and the mode 21 meV POP is found to have the highest impact on low field electron mobility at room temperature.
 Authors:
 Electrical Engineering Department, University at Buffalo, Buffalo, New York 14260 (United States)
 Publication Date:
 OSTI Identifier:
 22590547
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Applied Physics Letters; Journal Volume: 109; Journal Issue: 7; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BOLTZMANN EQUATION; CRYSTALS; DENSITY FUNCTIONAL METHOD; EFFECTIVE CHARGE; ELECTRIC FIELDS; ELECTRON MOBILITY; ELECTRONPHONON COUPLING; GALLIUM OXIDES; MONOCLINIC LATTICES; PHONONS; SCATTERING; TEMPERATURE RANGE 02730400 K
Citation Formats
Ghosh, Krishnendu, Email: kghosh3@buffalo.edu, and Singisetti, Uttam, Email: uttamsin@buffalo.edu. Ab initio calculation of electron–phonon coupling in monoclinic βGa{sub 2}O{sub 3} crystal. United States: N. p., 2016.
Web. doi:10.1063/1.4961308.
Ghosh, Krishnendu, Email: kghosh3@buffalo.edu, & Singisetti, Uttam, Email: uttamsin@buffalo.edu. Ab initio calculation of electron–phonon coupling in monoclinic βGa{sub 2}O{sub 3} crystal. United States. doi:10.1063/1.4961308.
Ghosh, Krishnendu, Email: kghosh3@buffalo.edu, and Singisetti, Uttam, Email: uttamsin@buffalo.edu. 2016.
"Ab initio calculation of electron–phonon coupling in monoclinic βGa{sub 2}O{sub 3} crystal". United States.
doi:10.1063/1.4961308.
@article{osti_22590547,
title = {Ab initio calculation of electron–phonon coupling in monoclinic βGa{sub 2}O{sub 3} crystal},
author = {Ghosh, Krishnendu, Email: kghosh3@buffalo.edu and Singisetti, Uttam, Email: uttamsin@buffalo.edu},
abstractNote = {The interaction between electrons and vibrational modes in monoclinic βGa{sub 2}O{sub 3} is theoretically investigated using abinitio calculations. The large primitive cell of βGa{sub 2}O{sub 3} gives rise to 30 phonon modes all of which are taken into account in transport calculation. The electronphonon interaction is calculated under density functional perturbation theory and then interpolated using Wannier–Fourier interpolation. The longrange interaction elements between electrons and polar optical phonon (POP) modes are calculated separately using the Born effective charge tensor. The direction dependence of the longrange POP coupling in a monoclinic crystal is explored and is included in the transport calculations. Scattering rate calculations are done using the Fermi golden rule followed by solving the Boltzmann transport equation using the Rode's method to estimate low field mobility. A room temperature mobility of 115 cm{sup 2}/V s is observed. Comparison with recent experimentally reported mobility is done for a wide range of temperatures (30 K–650 K). It is also found that the POP interaction dominates the electron mobility under low electric field conditions. The relative contribution of the different POP modes is analyzed and the mode 21 meV POP is found to have the highest impact on low field electron mobility at room temperature.},
doi = {10.1063/1.4961308},
journal = {Applied Physics Letters},
number = 7,
volume = 109,
place = {United States},
year = 2016,
month = 8
}

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Linearresponse calculation of electronphonon coupling parameters
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