High-field electron transport properties of <b> <i>α</i> </b> -Ga2O3

The high-field electron transport properties of alpha-phase gallium oxide (α-Ga2O3) under electric fields up to 1 MV/cm have been investigated using an integrated approach combining full-band first-principles calculations and Monte Carlo simulations. The electron–phonon scattering rates show strong temperature dependence at low electron energy, whereas at higher electron energy, the scattering rates become nearly temperature independent. At room temperature, the peak drift velocity reaches 2.5 × 107 cm/s at 400 kV/cm along x and y directions, decaying to 1.0 × 107 cm/s at 1 MV/cm. A drift velocity anisotropy emerges above roughly 200 kV/cm, with the drift velocity along the z direction consistently lower than that along x and y. Mode-resolved momentum relaxation analysis shows that Ag and Eg phonon modes are identified as the primary drivers of this anisotropy due to enhanced momentum randomization along the z direction. These results provide a comprehensive understanding of high-field electron transport in α-Ga2O3, offering valuable insights for optimizing high-power electronic devices.