Electrically tunable photonic crystals from long-range ordered crystalline arrays composed of copolymer colloids

Due to recent growing interest in mobile and e-book devices, new demand for a display with excellent outdoor readability, low power consumption, and reduced eye fatigue has led to research on reflective displays. The crystalline colloidal arrays (CCAs) composed of monodisperse copolymer colloids, investigated in this study, offer great potential for a tunable photonic crystal to be applied to the display technology, owing to its high reflectance and colour purity, as well as to the precise controllability of the photonic colour in a full visible regime. With the help of the manipulability of the particle size and the surface charge, structural colour with improved viewing angle was produced by mixing colloids with different particle sizes. In addition, the stop-band tuning mechanism under the electric field was systematically investigated.