Condensation of ordered nanocrystal thin films

45 Angstrom diameter dodecanethiol capped gold nanocrystals self-organize during solvent evaporation on a carbon substrate, with the final thickness of the nanocrystal film depending on solvent polarity. A quantitative model for the film thickness is presented, showing the film structure (thickness) to depend on the balance of van der Waals attraction between the particles themselves and between the particles and the substrate. This attraction influences the film thickness while permitting nanocrystal self-organization into hexagonal close-packed structures. Model predictions and measured film thicknesses agree well.