High Contrast Molecular Electrochromism
Abstract
The Reynolds (Georgia Tech) and Tomlinson (University of North Georgia) groups propose a joint theory and experimental research program seeking to understand the fundamental redox and optical properties of vibrantly colored molecular electrochromes, which switch to a fully clear state with high optical contrast. The program encompasses both anodically coloring electrochromes (ACE), and cathodically coloring electrochromes (CCE), while exploring chemistries that will lay the foundation for a new electrochromic color palette. To accomplish this, we propose to develop 3 separate classes of organic electrochromes, correlate the optoelectronic properties with single crystal structures, adsorb them onto high surface area nanoITO electrodes as a platform for materials characterization, and incorporate them into absorption/transmission electrochromic devices allowing us to collaborate with AFRL researchers. To accomplish this, the new classes of organic electrochromes includes two- and three-ring ACE heterocycle-phenylene systems where we probe aromaticity, steric, and heteroatom effects. Subsequently, we propose to explore a family of 3,4-dioxypyrrole based ACE molecules due to their even higher HOMO and LUMO, which simultaneously bring ease of oxidation and neutral molecule optical transitions into the UV. Finally, we propose a new concept in our electrochromism program studying CCEs by employing heterocycles with strong electron affinities, allowing access to anion radicals absorbing in the visible. By incorporate our new ACE and CCE molecules onto high surface area electrodes, and into high contrast electrochromic devices (ECDs) as platforms for materials characterization, we will probe electrochromic contrast, possibilities of electrochrome molecule interactions on the electrode surface, redox switching stability, and the ability to mix colors for both color depth and vibrancy, and for attaining neutral brown and black electrochromic materials potentially useful in the AF Dimmable visor program, along with color switchable windows and surfaces, in terrestrial, aircraft, and space-based applications. Having these electrodes and devices in hand will allow us to collaborate with others, especially interfacing with scientists at AFRL. Through all of this, our combined theory-synthesis-characterization approach empowers us to focus our experimental studies on those systems having the highest likelihood of success.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 21, 2022
- Source ID
- FA95502110420XX0
Entities
People
- John Reynolds
Organizations
- Air Force Office of Scientific Research
- Georgia Tech Research Corporation
- United States Air Force