|
|
【答案】应助回帖
★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★
chtycool: 金币+20, 翻译EPI+1, ★★★很有帮助 2013-05-24 08:36:48
|
Abstract: CuO nanowires were grown on the Cu substrate by low-temperature chemical vapor thermal oxidation. The samples were prepared at the temperature of 400℃ for 3h under different humidity, i.e. 500 sccm dry air, and 500, 1500, 3000 and 4000sccm wet air flows. The surface morphology and crystal structure of the products were characterized by Scanning Electron Microscopy(SEM), Field Emission Transmission Electron Microscopy(FETEM) and X-ray Diffraction(XRD). It was found that thermal oxidation in the water vapour environment could increase the density of CuO nanowires. High-density and uniform nanowires were formed in wet air, while only a small amount nanowires were formed in dry air. The CuO nanowires formed in 3000 sccm wet vapour have a vertical orientation and an appropriate density, with the diameter in a range of 40-100 nm and length 0.5-8 μm. The field emission properties were evaluated by comparison. Experimental results show that lower turn-on field and higher field enhancement factor could be obtained for CuO nanowires that grew under wet environment in the same flows of 500 sccm dry air. The field emission properties of the CuO nanowires grown under 3000 sccm wet vapour were optimal, having a low turn-on field of 1.4 V·μm-1 and a high field enhancement factor of 5948. |
|
回复此楼