Infrared electrochromic materials, devices and applications

As a color control technology, electrochromism has been rapidly developed in the past four decades, and be applied to various visible electrochromic applications such as smart windows, anti-glare rear-view mirrors and E-paper. With the comprehensive development of electrochromism, considerable interests have been extending into infrared electrochromism, which be exploitable for infrared electrochromic smart windows, optical communication, military camouflage and thermal control. In this review, the major classes of infrared electrochromic materials, namely organic small molecules, triphenylamine-based polymers, conducting polymers, metal complexes, metal oxides, plasmonic nanocrystals and emerging electrochromic materials are systematically described. Examples of prototype and commercial electrochromic devices are given. Finally, an outlook on the challenges and future trends of infrared electrochromism is also provided.