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 Na ₂C ₂O ₄ 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, NH ₃ and N(C ₂H ₅) ₃. The V _output 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 NH ₃ and N(C ₂H ₅) 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.