Porous silicon-based polymer replicas formed by bead patterning

Monodisperse, micrometer-sized polymer beads can be imparted with a porous nanostructure by softening them into a porous silicon photonic crystal template. Infiltration of the polymer and replication of the photonic spectral properties is verified by optical reflectivity measurements of the beads as they infuse into the nanostructure. The polymer beads can be removed from the porous Si template by dissolution of the template with a basic solution. This treatment destroys the photonic properties, although scanning electron microscopy (SEM) reveals that some nanotexturing remains in the polymer beads. This simple, solvent-free process provides a means to produce nanotextured particles of controllable size and shape. (c) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.