The anisotropic quasi-static permittivity of single-crystal β-Ga₂O₃ measured by terahertz spectroscopy

Authors

Prashanth Gopalan, University of Utah
Sean Knight, Linkoping University
Ashish Chanana, University of Utah
Megan Stokey, University of Nebraska-Lincoln
Praneeth Ranga, University of Utah
Michael A. Scarpulia, University of Utah
Sriram Krishnamoorthy, University of Utah
Vanya Darakchieva, Linkoping University
Zbigniew Galazka, Leibniz-Institut für Kristallzüchtung
Klaus Irmscher, Leibniz-Institut für Kristallzüchtung
Andreas Fiedler, Leibniz-Institut für Kristallzüchtung
Steve Blair, University of Utah
Mathias Schubert, University of Nebraska-LincolnFollow
Berardi Sensale-Rodriguez, University of UtahFollow

ORCID IDs

Prashanth Gopalan https://orcid.org/0000-0002-5201-1700

Sean Knight https://orcid.org/0000-0002-2758-6967

Ashish Chanana https://orcid.org/0000-0002-1374-0652

Megan Stokey https://orcid.org/0000-0003-0701-2218

Praneeth Ranga https://orcid.org/0000-0001-9002-1523

Michael A. Scarpulla https://orcid.org/0000-0002-6084-6839

Sriram Krishnamoorthy https://orcid.org/0000-0002-4682-1002

Vanya Darakchieva https://orcid.org/0000-0002-8112-7411

Zbigniew Galazka https://orcid.org/0000-0003-0812-2873

Klaus Irmscher https://orcid.org/0000-0001-9859-4465

Andreas Fiedler https://orcid.org/0000-0003-3404-0804

Mathias Schubert https://orcid.org/0000-0001-6238-663X

Document Type

Article

Date of this Version

2021

Citation

Appl. Phys. Lett. 117, 252103 (2020); doi: 10.1063/5.0031464

Comments

Published under license by AIP Publishing

Abstract

The quasi-static anisotropic permittivity parameters of electrically insulating beta gallium oxide (β-Ga₂O₃) were determined by terahertz spectroscopy. Polarization-resolved frequency domain spectroscopy in the spectral range from 200 GHz to 1 THz was carried out on bulk crystals along different orientations. Principal directions for permittivity were determined along crystallographic axes c and b and reciprocal lattice direction a*. No significant frequency dispersion in the real part of dielectric permittivity was observed in the measured spectral range. Our results are in excellent agreement with recent radio frequency capacitance measurements as well as with extrapolations from recent infrared measurements of phonon mode and high-frequency contributions and close the knowledge gap for these parameters in the terahertz spectral range. Our results are important for applications of β-Ga₂O₃ in high-frequency electronic devices.