Impurity band conduction in Si-doped β -Ga₂O₃films

By combining temperature-dependent resistivity and Hall effect measurements, we investigate donor state energy in Si-doped β-Ga2O3 films grown using metal-organic vapor phase epitaxy. High-magnetic field (H) Hall effect measurements (-90 kOe ≤ H ≤ +90 kOe) showed non-linear Hall resistance for T < 150 K, revealing two-band conduction. Further analyses revealed carrier freeze out characteristics in both bands yielding donor state energies of ∼33.7 and ∼45.6 meV. The former is consistent with the donor energy of Si in β-Ga2O3, whereas the latter suggests a residual donor state. This study provides critical insight into the impurity band conduction and the defect energy states in β-Ga2O3 using high-field magnetotransport measurements.