Proton‐Assisted Assembly of Colloidal Nanoparticles into Wafer‐Scale Monolayers in Seconds

Abstract Underwater adhesion processes in nature promise controllable assembly of functional nanoparticles for industrial mass production; However, their artificial strategies have faced challenges to uniformly transfer nanoparticles into a monolayer, particularly those below 100 nm in size, over large areas. Here a scalable “one‐shot” self‐limiting nanoparticle transfer technique is presented, enabling the efficient transport of nanoparticles from water in microscopic volumes to an entire 2‐inch wafer in a remarkably short time of 10 seconds to reach near‐maximal surface coverage (≈40%) in a 2D mono‐layered fashion. Employing proton engineering in electrostatic assembly accelerates the diffusion of nanoparticles (over 50 µm 2 /s), resulting in a hundredfold faster coating speed than the previously reported results in the literature. This charge‐sensitive process further enables “pick‐and‐place” nanoparticle patterning at the wafer scale, with large flexibility in surface materials, including flexible metal oxides and 3D‐printed polymers. As a result, the fabrication of wafer‐scale disordered plasmonic metasurfaces in seconds is successfully demonstrated. These metasurfaces exhibit consistent resonating colors across diverse material and geometrical platforms, showcasing their potential for applications in full‐color painting and optical encryption devices.