Positioning and finding quantum dots in silicon nanostructures

Control over the interaction between light and matter will have far-ranging consequences in chemistry, material science, physics, and biology. An important tool for the advanced control of light is offered by 3D photonic crystals with a photonic band gap, a range of frequencies for which light is forbidden to exist. We have developed methods to precisely control the location of lead sulfide quantum dots on silicon surfaces by attaching the dots to functionalized polymer brushes. Encouraged by successes on planar silicon wafers, we introduced quantum dots with polymer brushes in the nanopores of 2D and even 3D photonic band gap crystals. By synchrotron X-ray fluorescence tomography, we obtain detailed information on the positioning of the brushes and the dots. Notably, the quantum dot signal correlates very strongly with the brush signal, validating our approach. In optical experiments we find evidence for considerable emission inhibition in the 3D photonic band gap.