Electrically Responsive Structural-Color Materials

Abstract

Electrochromic materials, modulating their optical properties in response to electric fields, have shown widespread potential applications in displays, e-papers, camouflage, and smart windows, and so forth. However, conventional electrochromic materials based on chemical coloration mechanism exhibit noncontinuous color tuning ability and nontailorable color change and require high working voltages, significantly limiting their advanced applications. Recently, electrically responsive structural-color (ERSC) materials capable of addressing the above issues are regarded as the next-generation electrochromic materials and have attracted growing scientific interests. In this review, we summarize recent advances in ERSC materials through a seven-section framework. After introducing the background and significance of ERSC materials, we first classify representative structural platforms, including colloidal photonic crystals, inverse opals, liquid-crystal photonic structures, and plasmonic nanostructures. We then discuss the major electrically responsive mechanisms responsible for structural-color modulation, followed by an overview of fabrication strategies. Subsequently, key performance parameters, including color tuning range, color saturation, working voltage, response speed, hue stability, and cycling durability, are critically compared to clarify the merits and limitations of different ERSC systems. Finally, emerging applications, current challenges, and future prospects are discussed, aiming to provide guidance for the rational design and practical development of high-performance ERSC materials. This review will be helpful for facilitating the design and fabrication of outstanding ERSC materials and extend their advanced applications in color display, smart windows, information security, anticounterfeiting, dynamic camouflage, and so forth.