A tunable color filter using a hybrid metasurface composed of ZnO nanopillars and Ag nanoholes

Abstract

We propose the design of symmetrical and asymmetrical tunable color filters (TCFs) by using hybrid metasurface nanostructures in the visible wavelength range. They are composed of circular zinc oxide (ZnO) nanopillars and silver (Ag) nanoholes on a silica substrate. These TCFs exhibit ultrahigh transmission intensity over 90%, different tuning ranges, and polarization-dependent/independent characteristics. By changing the distance between the ZnO nanopillars and silica substrate, the resonant wavelength of TCFs could be tuned remarkably. Moreover, we also demonstrate the stability of TCFs under different disturbances and angles of incident light. Furthermore, the resonant wavelengths are red-shifted by increasing the ambient refraction index. TCFs exhibit great tunability and ultrahigh transmission intensity up to 100%. This design opens up an avenue to widespread optoelectronic applications, such as ultrahigh resolution color displays, high-efficiency biosensors, pressure sensors, and selective color filters.