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

Journal Article · Mon Aug 15 04:00:00 EDT 2016 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4961308· OSTI ID:22590547

Ghosh, Krishnendu; Singisetti, Uttam ^[1]

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1. Electrical Engineering Department, University at Buffalo, Buffalo, New York 14260 (United States)

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.

• OSTI ID: 22590547
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 7 Vol. 109; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

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