Electrochromics for printed displays and smart windows

This chapter reviews the basic principles, recent developments and preparation of electrochromic (EC) materials for applications in energy-saving smart windows and printed display. Smart windows are simply dynamic tintable glass that can change properties such as the solar heat gain coefficient (SHGC) and light transmittance in response to an electrical current/voltage. Display applications require different colors and/or at least three primary colors, which can result in other colors after mixing in order to obtain a wide range of colors. Recent advances in cost effective solution-processable coating techniques provide new opportunities for next-generation EC device owing to their simple process, low cost, and facile industrialization. One embodiment of particular interest is the availability of various printing techniques, such as screen printing, inkjet printing, flexographic printing, roll-to-roll printing press, slot die etc. This chapter also discusses the importance of attractive features such as mechanical flexibility, stretchability, and foldability in EC devices. The innovative EC devices in their soft form hold promises for the next-generation electronics especially for the stretchable, wearable, implantable and foldable display applications.