Enhancement in Electrical Conductivity of Transparent Single-Walled Carbon Nanotube Films

We have developed a simple and practical method to enhance the electrical conductivity of single-walled carbon nanotube (SWNT) films without loss of their transparency. In order to achieve an enhanced conductivity of transparent SWNT films, we carried out the formation of gold nanoparticles through the reduction of gold ions (Au³⁺) onto the SWNT films which manufactured by the vacuum filtration method. The electroless reduction of gold ions results from redox reactions between Au³⁺ and SWNT sidewalls just by immersion bare SWNT films into an ethanolic aqueous solution of gold salt (HAuCl₄) for several minutes. After the formation of gold nanoparticles, the electrical conductivity increased over two-fold of the initial conductivity and maintained the visible light transmittance ~80 %.