Reversible Metal Electrodeposition for Modulating Light

Title: Reversible Metal Electrodeposition for Modulating Light

The project team is developing windows whose tinting can be adjusted by applying a voltage between two transparent electrodes to either electroplate metal or remove the metal. These windows could reduce heating, cooling and lighting costs in buildings by 20% and allow people to enjoy the views through their windows even when the window is partially tinted to control glare.

This technology is expected to enable people to have better moods and be more productive by optimizing the amount of natural daylight they have. The project team is distributing kits to high school teachers and helping them show students how to make the windows. Through the construction of these dynamic windows, high school students are learning valuable concepts in electrochemistry, optics and architectural engineering with a project that is easy to visualize and has a clear purpose.

The adoption of high-performing dynamic windows based on reversible metal electrodeposition will increase the energy efficiency and comfort of buildings. Dynamic windows in buildings result in an average of 20% energy savings and 2% increase in workplace productivity due to improved management of lighting and temperature. The large extinction coefficients and intrinsic robustness of metals make them ideal materials for dynamic thin films.

Compared to traditional materials such as electrochromics, reversible metal electrodeposition is an underexplored strategy for constructing switchable thin films. Over the last five years, the McGehee and Barile groups have designed new strategies that enable enhanced control over reversible metal electrodeposition on transparent electrodes. The underlying objective of this research is to determine the physical and chemical parameters that yield rapid and reversible metal electrodeposition on transparent conducting electrodes with tailored optical properties and outstanding durability for optoelectronically switchable thin films.

This work is applicable to energy-saving dynamic windows for buildings and automobiles, switchable eyewear, and cameras. The project team’s unique research strategies are enabling the development of dynamic thin films with an unprecedented control over device optical contrast, switching speed, scalability, and cycle life. The work is aiding the progress of metal-based switchable films through the development of alkaline and Zn electrolytes with enhanced voltage stabilities, polymer-modified electrodes that allow for uniform tinting on a large scale, pulsed electrodeposition techniques to control device optics, and systematic durability studies that are enhancing the cycle lives of the devices.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.