Reported by Dr. Huajing Fang

    Electrochromic devices with reversible modulation of transmittance hold great potential for optoelectronic applications. However, the complicated internal structure not only increases the cost of production but also seriously limits the flexibility of design. In particular, the contents of the traditional electrochromic displays are predetermined by the patterns of the electrode and electrochromic layers and cannot be updated at will.

    Under this circumstance, Prof. Hong Wang group in XJTU developed a novel electrochromic layered-structure with greatly simplified configuration prepared by directly stacking the multifunctional ionic hydrogel onto tungsten oxide film. By applying a periodic bias, the ionic hydrogel based electrochromic device exhibits significant color change with large modulation of transmittance up to 70% and superior coloration efficiency, which is among the best overall performance when compared to the current electrochromic devices with much complicated structures. Moreover, we demonstrate, for the first time, an electrochromic device-based erasable and rewritable ionic writing board that can be driven by a bias as low as ~1 V. We anticipate that this work will enable completely new applications of hydrogels and electrochromic devices in smart windows and displays.

    The work is recently published as an article entitled “Multifunctional hydrogel enables extremely simplified electrochromic devices for smart window and ionic writing board” on Materials Horizons. Dr. Huajing Fang conducted the work as the first author. Prof. Hong Wang and Dr. Huajing Fang are the corresponding authors.

    The paper is accessed by

    http://pubs.rsc.org/en/content/articlelanding/2018/mh/c8mh00856f#!divAbstract