Angle-robust plasmonic color printing of deep subwavelength nanopixelated sodium metasurfaces

Plasmonic colors are attracting attention for their subwavelength small size, vibrant hues, and environmental sustainability beyond traditional pigments while suffering from angular and/or polarization dependency due to distinct excitations of lattice resonances and/or surface plasmon polaritons (SPPs). Here, we demonstrate the sodium metasurface-based plasmonic color palettes with polarization-independent wide-view angle (approximately >±60 deg in experiment and up to ±90 deg in theory) and single-particle-level pixel size (down to ~60 nm) that integrate both pigment-like and structure coloring advantages, fabricated by the templated nanorod-pixelated solidification of wetted liquid metals. Such intriguing performances are mainly attributed to the particle plasmon dominant spectral response by steering the filling profile and thus the interplay between localized surface plasmons and SPPs. Combining low material cost, potentially scalable manufacturing process, and pronounced optical performance, the proposed sodium-based metasurfaces will provide a promising route for advanced color information technology.