School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459.
Nanoscale. 2011 Apr;3(4):1845-9. doi: 10.1039/c0nr00986e. Epub 2011 Mar 8.
Single-walled carbon nanotube (SWCNT) thin films, containing a high-density of semiconducting nanotubes, were obtained by a gel-centrifugation method. The agarose gel concentration and centrifugation force were optimized to achieve high semiconducting and metallic nanotube separation efficiency at 0.1 wt% agarose gel and 18,000g. The thickness of SWCNT films can be precisely controlled from 65 to 260 nm with adjustable transparency. These SWCNT films were applied in photoelectrochemical devices. Photocurrents generated by semiconducting SWCNT enriched films are 15-35% higher than those by unsorted SWCNT films. This is because of reducing exciton recombination channels as a result of the removal of metallic nanotubes. Thinner films generate higher photocurrents because charge carriers have less chances going in metallic nanotubes for recombination, before they can reach electrodes. Developing more scalable and selective methods for high purity semiconducting SWCNTs is important to further improve the photocurrent generation efficiency by using SWCNT-based photoelectrochemical devices.
单壁碳纳米管 (SWCNT) 薄膜，含有高密度的半导体纳米管，通过凝胶离心法获得。优化琼脂糖凝胶浓度和离心力，以在 0.1wt%琼脂糖凝胶和 18000g 下实现高的半导体和金属纳米管分离效率。SWCNT 薄膜的厚度可以从 65nm 到 260nm 精确控制，具有可调的透明度。这些 SWCNT 薄膜应用于光电化学器件中。富半导体 SWCNT 薄膜产生的光电流比未经分类的 SWCNT 薄膜高 15-35%。这是因为去除金属纳米管减少了激子复合通道。较薄的薄膜产生更高的光电流，因为载流子在到达电极之前进入金属纳米管进行复合的机会更少。开发更具规模化和选择性的高纯度半导体 SWCNT 方法，对于提高基于 SWCNT 的光电化学器件的光电流产生效率非常重要。
