Gallium Oxide Heterojunction Diodes for Improved High-Temperature Performance

Abstract

-Ga_2O_3 based semiconductor devices are expected to have significantly improved high-power and high-temperature performance due to its ultra-wide bandgap of close to 5 eV. However, the high-temperature operation of these ultra-wide-bandgap devices is usually limited by the relatively low 1-2 eV built-in potential at the Schottky barrier with most high-work-function metals. Here, we report heterojunction p-NiO/n--Ga_2O_3 diodes fabrication and optimization for high-temperature device applications, demonstrating a current rectification ratio of more than 10^6 at 410 C. The NiO heterojunction diode can achieve higher turn-on voltage and lower reverse leakage current compared to the Ni-based Schottky diode fabricated on the same single crystal -Ga_2O_3 substrate, despite charge transport dominated by interfacial recombination. Electrical characterization and device modeling show that these advantages are due to a higher built-in potential and additional band offset. These results suggest that heterojunction p-n diodes based on -Ga_2O_3 can significantly improve high-temperature electronic device and sensor performance.

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Reproductions