(741e) Fabrication of Au Network Structure by Convective Self-Assembly for Transparent Conductive Films

Au network patterns are promising for transparent conductive materials because void spaces in the structures give transparency and Au particulate lines produce conductivity. Bottom-up approaches can offer a route to establishing a fabrication technique that is robust and cost-effective, and what is especially required is a template-free technique that can control the colloidal pattern. We have been studying the convective self-assembly (CSA) method, and successfully fabricated stripe, grid, and dot array patterns without any template. To further control the periodicity of the pattern, we recently modified the technique by incorporating a liquid-level manipulation (LLM) scheme in which the suspension is periodically pumped in or out. By using the modified technique, which we call CSA-LLM, we prepared stripe and grid networks of silica particles with controlled line width and spacing. In the present study, we fabricated grid patterns of Au nanoparticles by the CSA-LLM technique, and measured the transparency and conductivity of the patterns to clarify the relation between the periodicity of the pattern and the property as the transparent conductive films. We demonstrated superior performance of our technique to control the Au particulate line width and spacing. Furthermore we found out that the wettability of substrates varies the line thickness. Our technique can thereby produce transparent conductive films with a desired transparency and conductivity.