Primary and Secondary Reflective Color Realized by Full‐Solution‐Processed Multi‐Layer Structures

A full solution-based method is reported to fabricate multilayer thin film stacks for structural color applications. This in contrast the conventional fabrication methods that require high vacuum processes such as physical vapor deposition and magnetron sputtering, which significantly limits their practical use due cost long processing time. Copper/silicon dioxide/copper (Cu/SiO2/Cu) copper/titanium (Cu/TiO2/Cu) are chosen model system simple structure wide tunability. systematic investigation carried out each layer ensure good quality well its compatibility with all previous layers. Especially, a particulate Cu having optical properties distinct from of bulk obtained through solution deposition, where refractive index can be continuously tuned Both primary secondary colors achieved continuous manipulation both dielectric thickness top morphology on different substrates (e.g., silicon, glass, plastics, etc.).