【Device Papers】High responsive ethylene glycol gas sensor based on CuO@Ga₂O₃ p-n hetero-junctions materials

      Researchers from the Northwestern Polytechnical University have published a dissertation titled "High responsive ethylene glycol gas sensor based on CuO@Ga₂O₃ p-n hetero-junctions materials" in Journal of Alloys and Compounds.

Abstract

      As an emerging semiconductor material, Ga₂O₃ boasts a broader n-type band gap compared to SiC and GaN, the cornerstones of third-generation semiconductor technology. Its exceptional affinity for ethylene glycol (EG) makes it an ideal candidate for gas sensing research. However, the high operating temperatures required for Ga₂O₃ sensors have hindered its practical application. This study introduces CuO to form a p-n hetero-junction with Ga₂O₃ via a facile two-step solvothermal process. The resulting composite material establishes a space charge layer (SCL) that facilitates electron flow, enhancing the interaction between the sensing material and target gases, and significantly lowering the operational temperature. The synthesized CuO@Ga₂O₃ composite was meticulously characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). In addition, the correlation between gas response and operating temperature was further explored by changing the molar ratio of CuO/Ga₂O₃, and the gas-sensitive mechanism was analyzed. These results indicate that the study of CuO@Ga₂O₃ materials provides a new way to develop high-performance glycol sensors.

DOI：

https://doi.org/10.1016/j.jallcom.2025.182693