First principles study on the lattice thermal conductivity of a-phase Ga2O3

In this article, lattice thermal conductivity of alpha-phase Ga2O3 is investigated in a way of combining the first principles calculation and iterative solving the Boltzmann transport equation. Real-space displacement approach is employed in order to obtain both second- and third-order force constants. The effect of the microstructure on lattice thermal conductivity of alpha-phase Ga2O3 has been extensively studied and widely discussed. The results indicate that alpha-phase Ga2O3 exhibit a lower thermal conductivity compared with beta-phase Ga2O3 in a temperature range from 30 to 800 K. At room temperature, 300 K, the calculated thermal conductivities of alpha-phase Ga2O3 are 11.61, 9.38, and 8.94 Wm(-1) K-1 in the directions [100], [010], and [001], respectively. The lower thermal conductivity of alpha-phase Ga2O3 can be attributed to the mass difference and bond strength between Ga and O atoms. As for the phonon transport analysis, it is related to the three phonon scattering mechanism. Compared with beta-phase Ga2O3, alpha-phase Ga2O3 exhibits a higher anharmonic phonon scattering rate. Our study aims to help to understand the thermal transport mechanism of alpha-phase Ga2O3 material and provide useful guidance for the future device applications and enrich the existing state of the art. (C) 2022 Author(s).All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY)license (http://creativecommons.org/licenses/by/4.0/).

Automated summary

This article investigates the lattice thermal conductivity of alpha-phase Ga2O3 through first principles calculations and iterative solutions of the Boltzmann transport equation. The study explores the effect of microstructure on thermal conductivity and compares it with beta-phase Ga2O3. The results show that alpha-phase Ga2O3 has lower thermal conductivity due to mass difference and bond strength. The study provides valuable insights into the thermal transport mechanisms of alpha-phase Ga2O3 and its potential applications in future devices.