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

The thermal transport properties of Ga2O3 in different phases remain inadequately explored. We employ first-principles calculations and the phonon Boltzmann equation to systematically study the lattice thermal conductivity of beta-, alpha- and kappa-Ga2O3 . Our results reveal that kappa-Ga2O3 exhibits pronounced phonon anharmonicity due to its complex polyhedral configurations and weak bonding, resulting in significantly lower lattice thermal conductivity compared to beta- and alpha-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.