Thermal oxidation CuO nanowire gas sensor for ozone detection applications

In this study, cupric oxide nanowires (CuO NWs) on patterned interdigitated electrodes (PIEs) used as ozone (O-3) gas sensors, were successfully fabricated using thermal oxidation and the microelectromechanical systems (MEMS) technique. After the thermal oxidation process, CuO NWs with different heights and densities were fabricated using a pure copper seed layer with a thickness ranging from 0.5 mu m to 2 mu m. In this experiment, a low temperature, low concentration, and repeatable CuO NWs gas sensor was fabricated, which can detect O-3 gas at a low concentration of 50 ppb and low temperature of 100 degrees C with a high sensor response (40%). The concentration response of this gas sensor shows an increasing linear trend, with an increase of O-3 concentration in the range of 50 ppb - 300 ppb. Additionally, the results indicated that this CuO NWs gas sensor is more selective for O-3 than CO, CO2, C2H5OH, C3H6O, NO2, or NH3. While CuO has been less studied in O-3 detection compared with other semiconducting metal oxide materials, CuO NWs show potential applications in gas sensing devices for low-temperature and low-concentration O-3 environmental monitoring.