Electrochromic Conjugated Polymers for Multifunctional Smart Windows with Integrative Functionalities

In the advent of next-generation smart windows, materials play a multifunctional role, providing not only a pleasant environment for humans but also energy-efficient buildings and transportation. To this ends, smart windows tend to integrate multiple functions with the purpose of controlling external or sunlight input, self-power functionality, and display functionality. Among the several chromogenic mechanisms, electrochromic methods are fast and simple to control. Here, the recent electrochromic research on the integration of different functionalities is reviewed. Efforts toward the combination of functionalities have led to synergetic and technical breakthroughs over the years. These include development of new electrochromic polymers by main chain, as well as, side chain engineering, morphology and assembly control, and nanostructurization. In this context, electrochemical principles for smart windows offer easier integration of functionalities due to the integrative principles in common working mechanisms for color, energy, and information carrier controls. Some examples of multifunction devices are electrochromic capacitive windows, self-powered smart windows, and electrochromic-luminescent windows. Herein, discussed are the electrochromism from polymers and the electrochemically driven smart windows with two or more functionalities, which give rise to an innovative material with cooperative functions, featuring energy storage, energy generation, or light emission.