Heterostructure WSe₂-Ga₂O₃ Junction Field-Effect Transistor for Low-Dimensional High-Power Electronics

Layered materials separated from each bulk crystal can be assembled to form a strain-free heterostructure by using the van der Waals interaction. We demonstrated a heterostructure n-channel depletion-mode β-Ga₂O₃ junction field-effect transistor (JFET) through van der Waals bonding with an exfoliated p-WSe₂ flake. Typical diode characteristics with a high rectifying ratio of ∼10⁵ were observed in a p-WSe₂/n-Ga₂O₃ heterostructure diode, where WSe₂ and β-Ga₂O₃ were obtained by mechanically exfoliating each crystal. Layered JFETs exhibited an excellent I_DS-V_DS output as well as I_DS-V_GS transfer characteristics with a high on/off ratio (∼10⁸) and low subthreshold swing (133 mV/dec). Saturated output currents were observed with a threshold voltage of -5.1 V and a three-terminal breakdown voltage of +144 V. Electrical performances of the fabricated heterostructure JFET were maintained at elevated temperatures with outstanding air stability. Our WSe₂-Ga₂O₃ heterostructure JFET paves the way to the low-dimensional high-power devices, enabling miniaturization of the integrated power electronic systems.