Formation Mechanism, Patterning, and Physical Properties of Gold-Nanoparticle Films Assembled by an Interaction-Controlled Centrifugal Method

Gold nanoparticle (AuNP) films Stacked with individual AuNPs have been shown to exhibit novel electric, plasmonic, and photoelectric properties for wide applications. Here, we developed an efficient centrifugal method to assemble desirable large area monolayer, multilayer, and three-dimensional (3D) patterned AuNP films. The formation mechanism of AuNP films under different colloidal interactions was studied. The optimal energy barrier is about 10 k(B)T for assembling high quality monolayer AuNP films. The shift of localized surface plasmon resonance bands of the films follows a near-exponential distance decay with interparticle spacing s. A red-shift of about 190 nm reveals the strong near-field coupling at s similar to 0.9 nm. The electrical resistance exponentially increases with s, and exhibits Coulomb charging behavior at low temperature. Furthermore, patterning of AuNP films based on the lift-off technique was achieved and yielded 2D/3D complex structures with submicrometer critical dimension. This assembly method provides a feasible approach in developing future nanodevices and functional nanostructures.