First principles investigation of electron mobility enhancement of β-Ga₂O₃ doped with indium

β-Ga₂O₃ is one of the new-generation wide-bandgap semiconductor materials that has attracted much attention in recent years. However, the reported room-temperature electron mobility of β-Ga₂O₃ is much lower than GaN and SiC. Alloying Ga₂O₃ is expected to endow the material with superior carrier transport properties. Herein, we mainly investigate the electron mobility of pure Ga₂O₃, In-doped Ga₂O₃, and Al-doped Ga₂O₃ from first-principles considering acoustic deformation potential (ADP) scattering, polar optical phonon (POP) scattering and ionized impurity (IMP) scattering. The structure optimization, electronic band structure, and temperature-dependent and concentration-dependent electron mobility are investigated. The results show that the mobility of In-Ga₂O₃ is always the highest at 105-650 K, and POP scattering is the dominant factor limiting the electron mobility from 150-650 K. The mobility enhancement by In-doping is attributed to the smaller effective mass caused by the In 5s state despite its slightly increased electron-phonon coupling strength. The predicted electron mobilities for Ga₂O₃, Al-Ga₂O₃ and In-Ga₂O₃ at an electron concentration of 1.0 × 10¹⁷ cm^-3 are 151.5 cm² V^-1 s^-1, 137.8 cm² V^-1 s^-1 and 184.9 cm² V^-1 s^-1 at room temperature, respectively. This work provides an alternative route to enhance the electron mobility of Ga₂O₃ and guides in engineering their electronic transport properties for high-power electronics.