CO2-Expanded Liquid Deposition of Ligand-Stabilized Nanoparticles as Uniform, Wide-Area Nanoparticle Films

Deposition of nanoparticles into uniform, wide-area thin films using CO2 as an antisolvent is presented. Ligand-stabilized silver particles are controllably precipitated from organic solvents by pressurizing and expanding the solution with carbon dioxide. Subsequent addition of carbon dioxide as a dense supercritical fluid provides for removal of the organic solvent while avoiding the surface tensions common to evaporating solvents that are detrimental to nanoscale assemblies and structures. This brand new CO2-expanded liquid particle deposition technique allows for the targeted deposition of particles and results in more uniform and lower defect metal nanoparticle thin films than are provided by conventional solvent evaporation techniques.