Frankfurt 2006 – scientific programme

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Q: Quantenoptik und Photonik

Q 64: Photonische Kristalle V

Q 64.6: Talk

Thursday, March 16, 2006, 15:15–15:30, HI

Preparation and Characterization of Carbon Opals — •Bettina Friedel and Siegmund Greulich-Weber — Universität Paderborn, Department Physik, Warburger Str.100, 33098 Paderborn

3D photonic crystals for the visible spectral range are preferably fabricated from silica or plastic submicrospheres via self-assembling. Due to their insufficient refractive index such opals do not reveal complete photonic bandgaps. Therefore contemporarily research is focused on investigation suitable high index materials for infiltration of the interparticle voids of opals, followed by removal of the spheres. Compared to present high interest in these inverted opals, there is relatively low activity in development of new spherical particles. Higher refractive index, thermal resistance or supplementary properties, such as electrical conductivity could result in colloidal crystals, which meet desired requirements. We propose carbon as suitable material, because of its optical, electric and thermal properties. We have prepared monodisperse, smooth surfaced, submicron-sized carbon spheres, via pyrolysis of melamine-formaldehyde. These are stable even above 1200^∘C, offering a suitable template for inverse opals that require high temperatures, e.g. special ceramics. We will present our results on carbon spheres properties as well as on optical characterization of colloidal crystals.