A facile approach to directed assembly of patterns of nanoparticles using interference lithography and spin coating

We present a facile approach to the directed assembly of silica nanoparticles (less than or similar to 100-nm diameter) into periodic arrays on flat surfaces using interference lithography and spin coating. Periodic photoresist patterns, used as templates for the spin-coating process, were prepared using interference lithography. Silica nanoparticle dispersions were spin coated on these patterned surfaces, and the resist was removed, leaving periodic nanoparticle patterns on flat surfaces. Parallel arrays and continuous cross networks of particles were fabricated successfully with periods between hundreds of nanometers and several microns over areas of several square centimeters. The morphology (period, layer width and thickness, etc.) of the particle patterns can be controlled by varying the process conditions.