O2 and CO sensing of Ga2O3 multiple nanowire gas sensors

Gallium oxide nanowires were synthesized by a chemical thermal evaporation method using gallium metal as a source material. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy characterizations indicate that the obtained nanowires are well-crystallized single phase monoclinic Ga2O3. Multiple nanowire gas sensors were fabricated by dispensing the Ga2O3 nanowires on an interdigitated Pt-electrode. The Ga2O3 nanowire gas sensors show reversible response to O2 and CO gases in a working temperature range of 100–500 °C. A peak response is found at 300 °C for O2 gas and the peak response appears at 200 °C for CO gas. For both kinds of gases, the sensor response increases empirically with an increase of gas concentration. The results demonstrate the possibility of using the Ga2O3-based gas sensor at low working temperature field.