Photonic crystals are new functional materials with periodic dielectric constants and photonic bandgaps and they can control the transmission of light. Responsive photonic crystals can be prepared by introducing external stimuli -sensitive materials into the interspace of photonic crystals. Electrically responsive photonic crystals are formed by combining electroactive materials with photonic crystal structure. They can be applied to reflective full color display exhibiting unique advantages over other display technologies. In this review, the structure and the responsive mechanism of electrically responsive photonic crystal device are mainly introduced. Besides, according to different kinds of electroactive materials which are introduced into photonic crystals, the electrically responsive photonic crystals can be classified into liquid crystal-based, polyelectrolyte hydrogel-based, organometallic polymer gel-based, conductive polymer-based and core-shell electrically responsive photonic crystals. The development in recent years of all kinds of them are summarized. The application, existing problems and outlook in the field of reflective full color display device are presented.

Contents
1 Introduction
2 Responsive mechanism of responsive photonic crystals
3 Device structure of electrically responsive photonic crystals
3.1 Conductive substrate and electrolyte
3.2 Opal and inverse opal photonic crystal electroactive materials
4 Classification of electrically responsive photonic crystals
4.1 Liquid crystal-based electrically responsive photonic crystals
4.2 Polyelectrolyte hydrogel-based electrically responsive photonic crystals
4.3 Organometallic polymer gel-based electrically responsive photonic crystals
4.4 Conductive polymer-based electrically responsive photonic crystals
4.5 Core-shell electrically responsive photonic crystals
5 Application of electrically responsive photonic crystals
6 Existing problems and outlook