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

Abstract The thermal transport properties of Ga 2 O 3 in 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 -Ga 2 O 3 . Our results reveal that κ -Ga 2 O 3 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 -Ga 2 O 3 . This work provides critical knowledge of the fundamental phonon thermal transport properties of different-phase Ga 2 O 3 , as well as helpful guidance for the thermal design of Ga 2 O 3 -based high-power devices.