In situ growth of ZnO nanowires on Zn comb-shaped interdigitating electrodes and their photosensitive and gas-sensing characteristics

ZnO nanowires were grown in situ on Zn comb-shaped interdigitating electrodes by using a simple hydrothermal reaction of metallic Zn with Na2C2O4 in solution at 140 °C. ZnO nanowires were bridged across the trenched electrodes. In this process, the “pick and place” method of nanowire integration was avoided. The self-assembly grown ZnO nanowires had excellent performance as a sensor to ultraviolet (UV) light, NH3 and N(C2H5)3. The Voutput value was about 0.6 V in air, under UV illumination, however, it increased to 1.3 V. The sensitivities at 260 °C were 1.3 and 1.4 when the concentrations of NH3 and N(C2H5)3 gas were 0.5 and 0.9 ppm, respectively. The performance of this kind of sensors could be further improved by increasing the quantity of the Zn electrodes.