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 aluminum 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.

Optical Steganography Strategy Benefiting from Structural Color Cycling Based on Anodic Aluminum Oxide Membranes

“…The schematic profile of the multilayer stack is shown in Figure a; an AAO membrane is sandwiched between an ultrathin Ag layer and a reflective Al substrate. It is featured as high saturation and low angular dependence due to the thin-film interference in this plasmonic multilayer system . The porous AAO membrane in a hexagonal arrangement is generated from an Al foil by a lithography-free technology of electrochemical anodization; the hole pitch ( P AAO ) is 100 nm and the hole diameter ( D AAO ) is 30 nm.…”

“…It is featured as high saturation and low angular dependence due to the thin-film interference in this plasmonic multilayer system. 26 The porous AAO membrane in a hexagonal arrangement is generated from an Al foil by a lithography-free technology of electrochemical anodization; the hole pitch (P AAO ) is 100 nm and the hole diameter (D AAO ) is 30 nm. The thickness of the AAO membrane (T AAO ), as a key parameter in color rendering, can be precisely adjusted by the anodization time.…”

“…Meanwhile, a wafer-scale multilayer sample with structural color information can be obtained by employing the template-assisted method. The color is generated by the film interference between layers, the upper plasmonic surface promises high color saturation, and the middle AAO membrane offers large area coloring . Although this facile fabrication process becomes more practical, effective, and economical than the former lithographic cases, the smaller Δ E of this encryption strategy is still challenging.…”