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Title: Ab initio calculation of electron–phonon coupling in monoclinic β-Ga{sub 2}O{sub 3} crystal

Abstract

The interaction between electrons and vibrational modes in monoclinic β-Ga{sub 2}O{sub 3} is theoretically investigated using ab-initio calculations. The large primitive cell of β-Ga{sub 2}O{sub 3} gives rise to 30 phonon modes all of which are taken into account in transport calculation. The electron-phonon interaction is calculated under density functional perturbation theory and then interpolated using Wannier–Fourier interpolation. The long-range interaction elements between electrons and polar optical phonon (POP) modes are calculated separately using the Born effective charge tensor. The direction dependence of the long-range 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:
;  [1]
  1. 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; ELECTRON-PHONON COUPLING; GALLIUM OXIDES; MONOCLINIC LATTICES; PHONONS; SCATTERING; TEMPERATURE RANGE 0273-0400 K

Citation Formats

Ghosh, Krishnendu, E-mail: kghosh3@buffalo.edu, and Singisetti, Uttam, E-mail: uttamsin@buffalo.edu. Ab initio calculation of electron–phonon coupling in monoclinic β-Ga{sub 2}O{sub 3} crystal. United States: N. p., 2016. Web. doi:10.1063/1.4961308.
Ghosh, Krishnendu, E-mail: kghosh3@buffalo.edu, & Singisetti, Uttam, E-mail: uttamsin@buffalo.edu. Ab initio calculation of electron–phonon coupling in monoclinic β-Ga{sub 2}O{sub 3} crystal. United States. doi:10.1063/1.4961308.
Ghosh, Krishnendu, E-mail: kghosh3@buffalo.edu, and Singisetti, Uttam, E-mail: uttamsin@buffalo.edu. Mon . "Ab initio calculation of electron–phonon coupling in monoclinic β-Ga{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 β-Ga{sub 2}O{sub 3} crystal},
author = {Ghosh, Krishnendu, E-mail: kghosh3@buffalo.edu and Singisetti, Uttam, E-mail: uttamsin@buffalo.edu},
abstractNote = {The interaction between electrons and vibrational modes in monoclinic β-Ga{sub 2}O{sub 3} is theoretically investigated using ab-initio calculations. The large primitive cell of β-Ga{sub 2}O{sub 3} gives rise to 30 phonon modes all of which are taken into account in transport calculation. The electron-phonon interaction is calculated under density functional perturbation theory and then interpolated using Wannier–Fourier interpolation. The long-range interaction elements between electrons and polar optical phonon (POP) modes are calculated separately using the Born effective charge tensor. The direction dependence of the long-range 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 = {Mon Aug 15 00:00:00 EDT 2016},
month = {Mon Aug 15 00:00:00 EDT 2016}
}