摘要
Recent studies have demonstrated that significantly low sheet resistance (Rs) (<100 Ω/sq; comparable to ITO) were achieved in single-walled carbon nanotube (SWCNT) films treated with HNO <sub>3</sub> followed by thionyl chloride. Here we show that H <sub>2</sub> SO <sub>4</sub> can effectively reduce the Rs of SWCNT electrodes. H <sub>2</sub> SO <sub>4</sub> treatment generates defects (COOH and SO <sub>3</sub> H functionalities) on SWCNTs and the produced chemical functionalities are beneficial for enhancing the electrical conductivity in SWCNT electrodes. It is plausible that the H <sub>2</sub> SO <sub>4</sub> p-dopes the SWCNTs and the attachment of chemical functionalities helps to stabilize p-doping owing to their electron-deficient property. © 2009 Elsevier Ltd. All rights reserved.