Temperature-dependent electrical properties of β-Ga ₂ O ₃ Schottky barrier diodes on highly doped single-crystal substrates

Beta-phase gallium oxide (β-Ga ₂ O ₃ ) Schottky barrier diodes were fabricated on highly doped single-crystal substrates, where their temperature-dependent electrical properties were comprehensively investigated by forward and reverse current density - voltage and capacitance - voltage characterization. Both the Schottky barrier height and the ideality factor showed a temperature-dependence behavior, revealing the inhomogeneous nature of the Schottky barrier interface caused by the interfacial defects. With a voltage-dependent Schottky barrier incorporated into thermionic emission theory, the inhomogeneous barrier model can be further examined. Furthermore, the reverse leakage current was found to be dominated by the bulk leakage currents due to the good material and surface quality. Leakage current per distance was also obtained. These results can serve as important references for designing efficient β-Ga ₂ O ₃ electronic and optoelectronic devices on highly doped substrates or epitaxial layers.