Enhancement of Gas Sensitivity For MoO3 Nanobelt Sensor by Thermionic Field Emission

Nanostructures are at the forefront of transition metal oxide gas sensors due to their unique sensing properties enabled by a large surface-to-volume ratio. This paper presents a sensitivity enhancement technique for MoO₃ nanobelt based hydrogen sensing via surface treatment using a high-κ dielectric. A Pt/Ta₂O₅/MoO₃-nanobelt device has been fabricated and experimentally characterized, achieving a 6× sensitivity improvement compared to a reference device without the enhancement. The prototype also achieves the highest sensitivity and power efficiency among similar devices. Analysis shows that carrier transport can no longer be modeled by field emission but is instead thermionic field emission dominant.