State of the Art in Flexible Electrochromic Devices for Shading Applications

Electrochromic devices based on inorganic materials are a consolidate market reality with applications ranging from smart windows, automotive, sunglasses to displays. Recent years witnessed an intense interest in the development of alternative all-solid-state devices, mostly on flexible substrates, featuring organic and hybrid electrochromic materials. Amongst the main advantages of such new technological solutions are: reduction in production cost, lightweight, color tunability and switching speed. The literature already reports a good selection of book chapters and review articles giving the state of the art for organic electrochromic materials, both polymeric and molecular, yet there is a lack of contributions including the implementation of the most performing materials in fully assembled devices. The latter is a task at least as important as the development of performing materials. Given the multilayer nature of solid state electrochromic devices, the correct assembly of all different materials in a suitable sandwich structure, proper sealing and contacting as well as a final integration in the working environment, all represent the next challenge for commercialization of this technology. In this contribution we will focus our attention on shading applications, where devices have to fulfill the most demanding set of performances in order to compete with well-established inorganic technologies.