High Surface Area Transparent Conducting Oxide Electrodes with a Customizable Device Architecture

Herein, we report the development of optically transparent high surface area electrodes (HSEs) made of indium tin oxide (ITO) using a facile, template-free, scalable wet chemical synthetic approach. The transparent HSEs are electronically conductive and physically robust, with tunable electrochemically accessible roughness factors from 1 through ∼100. These transparent HSEs can serve as a broadly functionalizable scaffold ideally suited to bridge the gap between the need to minimize ionic and electronic transport lengths within a device and the need to achieve high loadings of active material per surface area (e.g. for high capacity as needed for batteries or high optical density as required for electrochromics or photovoltaics). This gap currently stands as a major hurdle for the utilization of many nanomaterials in electronic and optoelectronic devices. The synthetic approach described here for ITO is transferable to other transparent conducting oxide (TCO) materials. This is the first report of a large-pore, tunable, high surface area TCO electrode with excellent optical and conductive properties.