(23d) Self-Assembly and Patterning of Transferrable Ultra-Thin Films of Monolayer Nanoparticles

We have developed a universal, facile and robust method to prepare supported and unsupported ultra-thin films of monolayer nanoparticles that can serve as fundamentally interesting model systems for catalytic evaluation, optical investigation and magnetic study of metal, semiconductor and bimetallic nanoparticles, and this process is technologically important for the fabrication of ultra-thin monolayer or sandwiched multilayer film materials for nanotechnology applications such as optical devices, photovoltaic device, sensors, nano-catalysis, and magnetic storage. This kind of film can be easily transferred onto various substrates, such as glass slides and silicon wafers. The nanoparticles are closely packed in a monolayer manner, and are strong and stable enough to have part of the film standing without support. This facile method can be extended to various kinds of hydrophobic nanopaticles, such as metallic Au nanocrystals, semiconductor CdSe nanorods and nanoparticles, and magnetic FePt nanoparticles. Furthermore, the ultra-thin nanoparticle films supported on substrates were successfully patterned by e-beam lithography.