【Device Papers】P-type β-Ga₂O₃ films room-temperature NH₃ gas sensors with fast gas sensing and low limitation of detection

      Researchers from the Fudan University have published a dissertation titled "P-type β-Ga₂O₃ films room-temperature NH₃ gas sensors with fast gas sensing and low limitation of detection" in Journal of Materials Chemistry C.

Abstract

      The ammonia (NH₃) gas sensing is critical for practical applications in the environmental monitor of food, chemical and agricultural industry. It is hard to achieve room-temperature (RT) ammonia gas sensors fabricated on n-type Ga₂O₃ materials due to the weak exchange of carriers between NH₃ gas and surface-adsorbed oxygen ion species for n-type semiconductors. Good sensing performance is expected to be achieved by p-type Ga₂O₃ gas sensors due to the special gas adsorption and chemisorbed reactions of the surface hole accumulation layer. In this study, the p-type N-doped β-Ga₂O₃ films gas sensors with RT NH₃ gas sensing have been fabricated with wide hole accumulation layers of 44.5 nm at 300 K. The p-type β-Ga₂O₃ gas sensors exhibit a response and short response/recovery time of 219.1% and 42.3/60 s to 50 ppm NH₃. The good response linearity with a linearity factor of 0.33, and a low limitation of detection of 1 ppm are observed for the p-type β-Ga₂O₃ gas sensors. The good RT NH₃ sensing performance originates from the wide hole accumulation layer with the good gas adsorption and chemisorbed reactions. This work opens a horizon for the fabrication of the RT NH₃ gas sensors on p-type oxides films, lays the foundation for p-type β-Ga₂O₃ gas sensing, and paves the way for the evolution of the RT gas sensors fabricated on the p-type oxides.

DOI：

https://doi.org/10.1039/D4TC03313B