Wafer-scale plasmonic metal–dielectric–metal structural color featuring high saturation and low angular dependence

Abstract

Structural color has been studied through various methods due to its distinguished features of stability, durability, high information storage density and high integration. However, the artificial structural color samples do not exhibit superior performance in color saturation and low angular dependence. Here, we present an approach to acquire additive reflective color based on a metal–dielectric–metal (MDM) stack. The upper layer composed of Ag particles is perforated in a hexagonal arrangement which profits from the dielectric anodic aluminium oxide (AAO) membrane. The size and shape of the Ag particles are getting inhomogeneous as the deposition thickness of the upper layer increasing, which expands the desired absorption range of surface plasmons. The residual non-anodized Al foil serves as a highly reflective substrate for efficient color presenting through the thin-film interference in this plasmonic MDM system. As a result, the color gamut area of this MDM stack is extended 8 times in CIE chromaticity coordinates. Finally, a wafer-scale (diameter of 83 mm) badge of Harbin Engineering University (HEU) with highly saturated colors and a pattern characterized with low angle-dependent property (up to 60°) are presented, which exhibit promising prospects in commercial coloring and imaging.