Electron-Field-Emission Enhancement of CuO Nanowires by UV Illumination

The authors report the successful growth of CuO nanowires by thermal oxidation of Cu film deposited on CuO/glass template. It was found that we could achieve a higher nanowire density, longer average nanowire length by increasing the Cu film thickness. It was also found that turn-on fields were 14.1, 11.4 and 8.3 V/μm, while the field enhancement factors were 378, 493 and 552, for sample A with 0.5-μm-thick Cu film, sample B with 1-μm-thick Cu film and sample C with 2-μm-thick Cu film, respectively. Furthermore, it was found that we could improve the field emission ability and reduce the turn-on field from by simply illuminating the samples with ultraviolet light.