Elevated temperature dependence of the anisotropic visible-to-ultraviolet dielectric function of monoclinic β-Ga2O3

Authors

Alyssa Mock, University of Nebraska-LincolnFollow
Jeremy VanDerslice, J. A. Woollam Co.
Rafal Korlacki, University of Nebraska-LincolnFollow
John A. Woollam, University of Nebraska-LincolnFollow
Mathias Schubert, University of Nebraska - LincolnFollow

Document Type

Article

Date of this Version

2018

Citation

Applied Physics Letters 112, 041905 (2018)

DOI: 10.1063/1.5010936

Comments

Copyright 2018 AIP Publishing

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Applied Physics Letters 112, 041905 (2018) and may be found at https://doi.org/10.1063/1.5010936

Abstract

We report on the temperature dependence of the dielectric tensor elements of n-type conductive β-Ga2O3 from 22 °C to 550 °C in the spectral range of 1.5 eV–6.4 eV. We present the temperature dependence of the excitonic and band-to-band transition energy parameters using a previously described eigendielectric summation approach [A. Mock et al., Phys. Rev. B 96, 245205 (2017)]. We utilize a Bose-Einstein analysis of the temperature dependence of the observed transition energies and reveal electron coupling with average phonon temperature in excellent agreement with the average over all longitudinal phonon plasmon coupled modes reported previously [M. Schubert et al., Phys. Rev. B 93, 125209 (2016)]. We also report a linear temperature dependence of the wavelength independent Cauchy expansion coefficient for the anisotropic below-band-gap monoclinic dielectric tensor elements.