【Device Papers】Oxygen sensitivity of Ga₂O₃ nanosheet field-effect transistor

      Researchers from the Tianjin University have published a dissertation titled "Oxygen sensitivity of Ga₂O₃ nanosheet field-effect transistor" in Applied Surface Science.

Abstract

      The (100)-oriented Ga₂O₃ nanosheet is grown on the GaAs by a thermal oxidation method, and then transferred to SiO₂/n⁺-Si substrate by van der Waals forces. Afterwards, the Ga₂O₃ nanosheet with contamination-free surface is made to field effect transistors (FET), showing a high current on/off ratio of > 10⁷ by backgate modulation. As oxygen pressure PO₂ increases from 0.01 to 100 Pa, the threshold voltage V_T of the nanosheet FET presents an evident negative shift from −20.3 V to −28.0 V. Moreover, the FET shows high photoresponse controllability with pulsed 254 nm illumination. The higher PO₂ is found to induce the lower light current under illumination and the faster decay process when the illumination is interrupted. The oxygen sensitivity of Ga₂O₃ nanosheet FET can be well explained by the interactions between oxygen adsorption and unsaturated dangling bonds on its surface.

DOI：

https://doi.org/10.1016/j.apsusc.2025.162391