Logan Kiefer1 Christian Robert1 Taylor Sparks1

1, University of Utah, Salt Lake City, Utah, United States

Transparent electrochromic materials darken with an applied voltage, making them useful in a variety of applications. The optical transitions of electrochromic materials vary with temperature, a phenomenon necessitating consideration when designing for applications with fluctuating temperatures such as variable tint ski goggles. This work explores how the kinetics of optical transitions of one organic electrochromic molecule, ethyl viologen diperchlorate, vary with temperature. Studies have been conducted on the kinetics of optical transitions of ethyl viologen diperchlorate electrochromic devices at room temperature, and they have also been conducted on other electrochromic molecules at different temperatures, however these studies do not contain findings about the temperature effects on the electrochromic transitions of ethyl viologen diperchlorate. This work aims to investigate these temperature effects by measuring the optical transitions of ethyl viologen diperchlorate electrochromic cells at a variety of temperatures and comparing the kinetics at each temperature. Testing reveals that temperature affects the darkness these electrochromic cells can achieve as well as the rate at which they reach this darkness. At lower temperatures the cells take a longer time to transition, yet they reach a darker state. With increasing temperature, these cells transition more quickly, and achieve a lighter fully-darkened state.