Structural Color Manipulation Using Tunable Photonic Crystals with Enhanced Switching Reliability




The tuning stability of an electrically tunable photonic crystal composed of long-range ordered crystalline colloidal arrays is significantly improved by modifying an ITO electrode with ion-exchange resins. The thin layer of over-coating on the ITO surface increases the number of cycles of stable color-tuning switching from red to green to over 800 times, which is the best result ever reported for a tunable photo­nic crystal whose stop-band position can be manipulated more than 100 nm.