Electrophoretic Deposition of MultifunctionalNanoparticle Films

Even though the properties of individualnanoparticles are fascinating and technologicallypromising, to harness these properties, however, theparticles need to be assembled in an array to form asuperlattice. While there are ways of forming smallordered monolayers and crystals of nanoparticlesthere is no satisfactory method to deposit largeareas of ordered multilayers films ofnanoparticles. Dry casting and spin coating resultin films that are typically not uniform and bynature, unpatterned. Multilayer, ordered andpatterned films of nanoparticles are essential fordevice fabrication. We have developed a method toelectrophoretically deposit nanoparticles to formmultilayer films with remarkable topographical,optical, mechanical, and electrical properties. Wehave shown how the surface defects of nanoparticlescan be used as an advantage to form almost defectfree arrays with average roughness less than thediameter of the individual particles! Preliminarystudies on the electrical, thermal,and mechanicalproperties of these films are reported.