Lattice thermal conductivity of β-, α- and κ- Ga2O3: a first-principles computational study

Abstract The thermal transport properties of Ga2O3 of different phases remain inadequately explored. We employ first-principles calculations and the phonon Boltzmann equation to systematically study the lattice thermal conductivity of β-, α- and κ-Ga2O3. Our results reveal that κ-Ga2O3 exhibits pronounced phonon anharmonicity due to its complex polyhedral configurations and weak bonding, resulting in significantly lower lattice thermal conductivity compared to β- and α-Ga2O3. This work provides critical knowledge of the fundamental phonon thermal transport properties of different-phase Ga2O3, as well as helpful guidance for the thermal design of Ga2O3-based high-power devices.