Acoustic phonon characteristics of (001) and (2¯01) β-Ga2O3 single crystals investigated with Brillouin–Mandelstam light scattering spectroscopy

D Dylan Wright (Department of Materials Science and Engineering, University of California 1 , Los Angeles, California 90095,) E Erick Guzman (Department of Materials Science and Engineering, University of California 1 , Los Angeles, California 90095,) M Md Sabbir Hossen Bijoy (Materials Research and Education Center, Department of Mechanical Engineering, Auburn University 3 , Auburn, Alabama 36849,) R Richard B. Wilson (Department of Mechanical Engineering, Materials Science and Engineering, University of California 4 , Riverside, California 92521,) D Dinusha Herath Mudiyanselage (School of Electrical, Computer, Energy Engineering, Arizona State University 1 , Tempe, Arizona 85281,) H Houqiang Fu (School of Electrical, Computer, Energy Engineering, Arizona State University 1 , Tempe, Arizona 85281,) F Fariborz Kargar (Materials Research and Education Center, Department of Mechanical Engineering, Auburn University 3 , Auburn, Alabama 36849,) A Alexander A. Balandin

Abstract

We report an investigation of the bulk acoustic phonons of (001) and (2¯01) β-Ga2O3 ultra-wide bandgap single crystals using Brillouin–Mandelstam spectroscopy. Pronounced anisotropy in the acoustic phonon dispersion and velocities was observed across different crystal directions. The measured, polarization-branch averaged, acoustic phonon velocities for the crystallographic directions of interest suggest that the difference in phonon velocities contributes to the anisotropy of the reported thermal conductivity of β-Ga2O3, in addition to possible variations in phonon lifetimes. The obtained information for acoustic phonons can be used for developing accurate theoretical models of phonon scattering and optimization of thermal and electrical transport in this technologically important ultra-wide bandgap semiconductor.

Article Details

Volume / Issue Vol. 127, Issue 5
Published August 04, 2025
ISSN 0003-6951
Publisher American Institute of Physics

Journal Info

Applied Physics Letters

American Institute of Physics

ISSN: 0003-6951 Physical Sciences

Authors (8)

D

Dylan Wright

Department of Materials Science and Engineering, University of California 1 , Los Angeles, California 90095,

E

Erick Guzman

Department of Materials Science and Engineering, University of California 1 , Los Angeles, California 90095,

M

Md Sabbir Hossen Bijoy

Materials Research and Education Center, Department of Mechanical Engineering, Auburn University 3 , Auburn, Alabama 36849,

R

Richard B. Wilson

Department of Mechanical Engineering, Materials Science and Engineering, University of California 4 , Riverside, California 92521,

D

Dinusha Herath Mudiyanselage

School of Electrical, Computer, Energy Engineering, Arizona State University 1 , Tempe, Arizona 85281,

H

Houqiang Fu

School of Electrical, Computer, Energy Engineering, Arizona State University 1 , Tempe, Arizona 85281,

F

Fariborz Kargar

Materials Research and Education Center, Department of Mechanical Engineering, Auburn University 3 , Auburn, Alabama 36849,

A

Alexander A. Balandin