Solution processed, flexible, and low cost transparent electrodes are highly desirable as a replacement for the increasingly expensive and brittle ITO. Singlewalled carbon nanotubes (SWNTs) should be an excellent material for such applications since they possess an excellent combination of superior electrical and mechanical properties. However, sufficient SWNT based transparent electrodes are lacking due to the presence of SC-SWNT, inducing poor tube/tube contacts and high sheet resistance. We have recently developed a method in which SWNTs are absorbed from regular bulk solutions onto surfaces with different functionalization leading to surfaces possessing either SC-SWNT or MET-SWNT enrichment. The relatively recent ability to observe how specific functional groups interact with an isolated SWNT through various spectroscopic methods is allowing for key breakthroughs in fields such as nanotube separation and SWNT based electronics. Taking advantage of these previous results, this work shows how to absorb only MET-SWNT on surfaces, ideal for electrodes since a lower sheet resistance will result. Additionally, this work has important implications for solar cell technology that requires thin transparent electrodes. Because the approach here can demonstrate networks of robust MET-SWNTs fabricated at room temperature that could serve as electrodes, it would also be compatible with lexible organic solar cells.
© 2008 Optical Society of AmericaPDF Article