High‐Chroma Color Coatings Based on Ag/SiO2/Ti/SiO2 Structures

Abstract

A four‐layer metal–dielectric–metal–dielectric (MDMD) stack design for color control is demonstrated. This stack incorporates Ag, SiO2, and Ti as materials, enabling wide absorbance bands, high reflectance peaks, and a strongly tunable color. A wide gamut is obtained by varying the thickness of the SiO2 cavity layer, and the resulting colors exhibit outstanding luminance and chroma. Coatings of red, green, and blue colors are designed and deposited. These coatings demonstrate a very close agreement between the simulated and experimental results. The chroma of the coatings is found to be similar to or exceeded the limits of the Pointer gamut, an empirical gamut of colors in reflectance. This shows that, in the generation of surface color, even for a simple four‐layer stack, the performance of thin‐film coatings can rival or exceed that of traditional paints and dyes.