Thermal transport of defective β-Ga₂O₃ and B(In)GaO₃ alloys from atomistic simulations

β-Ga₂O₃ is a new generation of semiconductor material with a wide bandgap of 4.9 eV. However, the β-Ga₂O₃ devices inevitably produce defects within them after irradiation, leading to changes in their thermal conductivities. At present, the effect of radiation-damage-induced defects on thermal conductivity of β-Ga₂O₃ has not been carried out. Herein, we have employed molecular dynamics simulations to investigate the impact of defects on the thermal transport of β-Ga₂O₃, and the obtained thermal conductivity of non-defect β-Ga₂O₃ is in good agreement with recent reports. Our findings indicate that the thermal conductivity of β-Ga₂O₃ at room temperature exhibits a consistent decrease with an increase in the concentration of Ga vacancies, but shows a decreasing and then increasing trend as the number of O vacancies increases. In addition, doping/alloying is found to improve the irradiation resistance of β-Ga₂O₃ based on reported defect formation energy calculations, so the mechanism of alloying effect on the thermal conductivity is deeply analyzed through first-principles calculations. Moreover, the lattice thermal conductivities of ordered InGaO₃ and BGaO₃ alloys are predicted by solving the phonon Boltzmann transport equation. The obtained results that κ(Ga₂O₃) = κ(BGaO₃) > κ(InGaO₃) are attributed to the combined effect of volume, specific heat capacity, group velocity, and phonon lifetime of the three materials. This work can help to disclose the radiation damage influence on thermal properties of β-Ga₂O₃ semiconductors.