Mie resonant structural colors based on ZnO spheres and their application in multi-color Pattern: Especially realization of red color

Mie resonant structural colors have recently emerged as a promising approach for large-scale and high-precision material appearance design to replace plasmonic structures. However, Mie resonant structural colors are still limited in the gamut of red because high-order multipoles such as electric and magnetic quadrupoles (EQ, MQ) usually exist in blue band when the electric dipole (ED) and magnetic dipole (MD) located in red band. Here we achieved pure red Mie resonant structural color based on ZnO spheres. Both simulation and experimental results proved that the dipole resonance and quadrupole resonance can be separated effectively by decreasing the refractive index of the resonator. By comparing different materials, ZnO is the most suitable material to generate a pure red color. Further, by controlling the distance of ZnO spheres on the substrate, high-order multipole resonance was inhibited completely and pure red Mie resonant structural color was achieved. In addition, by tuning the size of ZnO spheres, bright purple, blue, green, yellow, orange, and red colors were also realized. Finally, complex patterns can be easily made by the spraying method. This work opens new perspectives on full-color Mie resonant structural colors.