Lee Yang Doo, Lee Hyeon Jae, Han Jong Hun, Yoo Jae Eun, Lee Yun-Hi, Kim Jai Kyeong, Nahm Sahn, Ju Byeong-Kwon
Department of Materials Science and Engineering, Korea University, Anam-dong, Seongbuk-gu, Seoul 136-713, Republic of Korea.
J Phys Chem B. 2006 Mar 23;110(11):5310-4. doi: 10.1021/jp0548624.
Double-walled carbon nanotubes (DWCNTs) were synthesized by catalytic chemical vapor deposition using Fe-Mo/MgO as a catalyst at 1000 degrees C under the mixture of methane and hydrogen gas. The nanotubes were purified by acid but were not damaged. Thermogravimetric analysis revealed the purity of the tubes to be about 90%. The high-resolution transmission electron microscopy image showed that DWCNTs have inner tube diameters of 1.4-2.6 nm and outer tube diameters of 2.3-3.4 nm. We observed radial breathing modes in Raman spectra, which are related to the diameter of inner nanotubes. The purified DWCNTs were mixed with organic vehicles and glass frit, and then they were screen-printed on glass substrate coated with indium tin oxide. The field emission properties of the screen-printed DWCNT films were examined by varying the amount of glass frit ingredient within the DWCNT paste. The results showed that DWCNT emitters had good emission properties such as turn-on field of 1.33-1.78 V/microm and high brightness. When the applied anode voltage was gradually increased, current density and brightness became saturated. We also observed DWCNTs adsorbed on the anode plate; they were DWCNTs peeled off from the cathode plate for field emission measurement.
采用催化化学气相沉积法，以Fe-Mo/MgO为催化剂，在1000℃、甲烷与氢气混合气体环境下合成了双壁碳纳米管（DWCNTs）。这些纳米管经酸纯化但未受损。热重分析表明，这些碳纳米管的纯度约为90%。高分辨率透射电子显微镜图像显示，DWCNTs的内管直径为1.4 - 2.6nm，外管直径为2.3 - 3.4nm。我们在拉曼光谱中观察到了径向呼吸模式，其与内部纳米管的直径相关。将纯化后的DWCNTs与有机载体和玻璃料混合，然后丝网印刷在涂有氧化铟锡的玻璃基板上。通过改变DWCNT糊剂中玻璃料成分的含量，研究了丝网印刷的DWCNT薄膜的场发射特性。结果表明，DWCNT发射体具有良好的发射特性，如开启场为1.33 - 1.78V/μm且亮度高。当施加的阳极电压逐渐增加时，电流密度和亮度趋于饱和。我们还观察到阳极板上吸附有DWCNTs；它们是从用于场发射测量的阴极板上剥离下来的DWCNTs。
