Site-specific self-assembly of Si/SiOx nanoparticles on micropatterned poly(dimethylsiloxane) thin films

Recent efforts have focused on the design of 2D and 3D assemblies with the goal of creating highly ordered supramolecular structures. Ultrathin films patterned with topologically different surface chemical functionality may be used as a template for such elaborate architectures. Surface functionalization can be used to impose site-specific assembly and can further lead to the fabrication of highly ordered structures, which have a great importance in the microelectronic and optoelectronic industry. Recently, we have demonstrated the fabrication of surface modified Si/SiOx nanoparticles and their self-assembly on various surfaces. We presently report the specific self-assembly of Si/SiOx nanoparticles on poly(dimethylsiloxane) (PDMS) spin-cast films. The desire to create regions of SiOx, which coexist with silicones in a two-dimensional film, is motivated by the difference in surface energies and affinity contrast between SiOx and PDMS. As presently reported, the selectivity of the deposition of Si/SiOx nanoparticles on PDMS versus UV/O3 converted SiOx offers a great opportunity for the fabrication of periodic structures with large modulation in refractive index.