Electrophoretic Plasmonic Ink for Dynamic Color Display

Abstract Plasmonic metal nanostructures generate vivid colors with high spatial resolution. Active control of plasmonic pixels by electrical means, which is compatible with integrated circuit technologies, is a promising technique for dynamic full color reflective display. However, the development of electrical plasmonic display is still limited by the difficulties in cost‐effective construction of active plasmonic pixels over large areas. This study demonstrates the achievement of electrical plasmonic display in full color by electrophoretic movement control of plasmonic noble metal nanocrystals in an organic electrolyte solvent. The persistent issues of nanoparticle aggregation and irreversible deposition in electrophoresis are addressed through appropriate surface modifications of the plasmonic nanocrystals, enabling them as advantageous nanoscale colorful pigments with long‐term durability. A weak electric field therefore allows color display with high contrast, high saturation, and electrical reconfigurability. The ink containing plasmonic pigments is further assembled into microfluidic chips to display different characters. The strategy will pave the way towards the development of plasmonic electronic paper in full color.