CuO nanowire-based humidity sensors prepared on glass substrate

Abstract The authors report the growth of CuO nanowires (NWs) on glass substrate and the fabrication of CuO NW humidity sensors. It was found that average length of the CuO NWs increased from 0.4 μm to 2.8 and 6 μm, respectively, as we increased the initial copper film thickness from 0.5 μm to 1 and 2 μm after oxidation. It was also found that resistance of the CuO NWs increased as we increased the relative humidity due to the p-type nature of CuO. Furthermore, it was found that samples with a larger initial copper film thickness and thus a longer average CuO NW length could provide a larger sensor response.