Photonic crystals are materials patterned with a periodic variation of the refractive index creating a range of forbidden optical frequencies called a photonic band gap- A photonic band gap modifies fundamentally the propagation and emission processes of light. Based upon these effects novel integrated-photonic materials can be designed, opening various new areas of applications. We propose to synthesize photonic crystals, composed of colloidal magnetic spheres with mono- and bimodal sphere size. For this purpose monodisperse magnetic spheres will be produced in a first Step and than assembled to large 3D crystals through a novel magnetic field assisted crystallization process via two different routes. 1. Crystallization of large defect-free 2D crystals in a magnetic field and the following arrangement of these layers to a 3D crystals. 2. One Step crystallization of 3D crystals in a magnetic field. Structure and optical properties of the photonic crystals will be investigated by confocal and electron microscopy, UV-VIS spectroscopy and measurements of the excited-state, lifetime of inserted dye molecules.
Photonic crystals are materials patterned with a periodic variation of the refractive index creating a range of forbidden optical frequencies called a photonic band gap- A photonic band gap modifies fundamentally the propagation and emission processes of light. Based upon these effects novel integrated-photonic materials can be designed, opening various new areas of applications. We propose to synthesize photonic crystals, composed of colloidal magnetic spheres with mono- and bimodal sphere size. For this purpose monodisperse magnetic spheres will be produced in a first Step and than assembled to large 3D crystals through a novel magnetic field assisted crystallization process via two different routes. 1. Crystallization of large defect-free 2D crystals in a magnetic field and the following arrangement of these layers to a 3D crystals. 2. One Step crystallization of 3D crystals in a magnetic field. Structure and optical properties of the photonic crystals will be investigated by confocal and electron microscopy, UV-VIS spectroscopy and measurements of the excited-state, lifetime of inserted dye molecules.