Wide gamut, angle‐insensitive structural colors based on deep‐subwavelength bilayer media

Abstract

Abstract Wide gamut and angle‐insensitive structural colors are highly desirable for many applications. Herein, a new type of lithography‐free, planar bilayer nanostructures for generating structural colors is presented, which is basically composed of a deep‐subwavelength, highly absorbing dielectric layer on an opaque metallic substrate. Experimental results show that a galaxy of brilliant structural colors can be generated by our structures, and which can cover ∼50% of the standard red–green–blue color space by adjusting the nanostructure dimensions. The color appearances are robust with respect to the angle of vision. Theoretical partial reflected wave analyses reveal that the structural color effect is attributed to the strong optical asymmetric Fabry–Perot‐type (F–P‐type) thin‐film resonance interference. The versatility of the structural color properties as well as the simplicity of their fabrication processes make this bilayer structures very promising for various applications, such as security marking, information encryption, and color display, etc.