Zinc anode-based and plasmonic-based electrochromic devices for dynamic light modulation
Creators: Zhang, Wu
Publisher: name: University of Alberta Library
Year: 2024

<p>Electrochromism is the phenomenon where the optical transmittance or absorbance of a material changes under an applied electric potential. When a voltage is applied to an electrochromic material, the optical properties of the material are altered in a reversible fashion. Owing to their optical switching behavior, electrochromic materials provide great opportunities for a variety of energy-saving and color-tuning applications, including smart windows, multicolor displays, electronic skins and color-tunable optical elements.<br>
In this thesis, we developed a promising Zinc anode-based electrochromic device (ZECD) platform. The ZECD platform not only reduces the energy consumption during operation, via the energy retrieval functionality, but also exhibits a rapid spontaneous switching behavior due to the high value of redox potential difference between the metal anode and the electrochromic cathode. Furthermore, ZECDs enable independent operation of top and bottom electrochromic electrodes, thus providing additional operation flexibility of the devices through the utilization of dual electrochromic layers under the same or different color states. As such, the color overlay effect can greatly broaden the color palettes via altering the coordinates of the 2D Commission Internationale de l&#39;Eclairage (CIE) color space. Moreover, a dual-mode electrochromic device having both self-coloring and self-bleaching operations is demonstrated via coupling the ZECD platform into a rocking-chair type electrochromic device. By employing a hybrid electrolyte system, the rocking-chair type device is shown to be capable of spontaneously bleaching through the redox potential difference between the anodic and cathodic electrodes.<br>
Furthermore, the demonstrations of the manipulation of plasmonic silver adatoms through reversible metal deposition are presented for dynamic light modulation. The reversible silver metal deposition on Indium Tin Oxide (ITO) glasses, having tunable nanostructures, along with their localized surface plasmon resonance (LSPR), is considered as a promising strategy for dynamic color displays. The voltage-activated reversible silver nanoparticles deposition enables a wide range of dynamic plasmonic color change of 100 nm, and also facilitates a size and shape control of the grown silver nanoparticles. The silver nanoparticles interact with visible light through LSPR, the size and shape of the particles affect their optical properties. We further demonstrate a novel concept for solar-regulated dynamic windows by depositing thin films of gold on glass substrates to serve as transparent conductive electrodes. By employing a reversible silver metal deposition technique, we develop a dual-band dynamic window capable of independent regulation of visible light and near-infrared radiation. This technique, which permits the targeted adjustment of visible light and near-infrared radiation, opens possibilities for diverse operational modes – bright, light, and dark modes. The developed platform not only has the potential to reduce building energy consumption but also maintains optimal indoor lighting conditions.<br>
The outcomes of this thesis represent novel strategies for fabricating dynamic windows, provide indispensable building blocks for future generations of transparent multicolor displays, as well as open up new areas of research into the development of future electrochromic devices.</p>