Freestanding films of crosslinked gold nanoparticles prepared via layer-by-layerspin-coating

Abstract

A new, extremely efficient method for the fabrication of films comprised of goldnanoparticles (GNPs) crosslinked by organic dithiols is presented in this paper. Themethod is based on layer-by-layer spin-coating of both components, GNPs andcrosslinker, and enables the deposition of films several tens of nanometers in thicknesswithin a few minutes. X-ray diffraction and conductance measurements revealthe proper adjustment concentration of the crosslinker solution of the criticalis in order to prevent the destabilization and coalescence of particles. UV/visspectroscopy, atomic force microscopy, and conductivity measurements indicatethat films prepared via layer-by-layer spin-coating are of comparable quality tocoatings prepared via laborious layer-by-layer self-assembly using immersion baths.Because spin-coated films are not bound chemically to the substrate, they can belifted-off by alkaline underetching and transferred onto 3d-electrodes to produceelectrically addressable, freely suspended films. Comparative measurements of the sheetresistances indicate that the transfer process does not compromise the film quality.