Berlin 2005 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 37: Photonische Kristalle I

HL 37.8: Vortrag

Montag, 7. März 2005, 11:45–12:00, TU P270

Light-emitting biological photonic crystals — •Melanie El Rharbi-Kucki and Thomas Fuhrmann-Lieker — Makromolekulare Chemie und Molekulare Materialien, FB Naturwissenschaften, Universität Kassel, Heinrich-Plett-Str. 40, 34109 Kassel

Biological nanostructures are widespread in nature. They are extremely diverse in material composition, structural complexity and function. In many animal phyla photonic crystal structures in the range of the wavelength of visible light are used to produce brilliant structural colours. Here we present one of the few examples of photonic crystal structures in plants. The silica cell wall of the centric diatoms Coscinodiscus granii and Coscinodiscus wailesii can be regarded as slab waveguide photonic crystals with hexagonal and square structure. The lattice constants of the photonic structures are in the dimension of the UV to NIR range. Light is the main energy source for diatoms and an essential factor giving information about the environment they are living in. We investigate the optical properties of the diatom shell with respect to the biological function and the possibility for technological application. To explore the control of absorption and emission of light by the photonic structures, various laser dye molecules were incorporated into the diatom shell by the use of an in vivo-technique. We give an overview on dye classes that are incorporated into the photonic crystal structure and present recent results on the microscopically resolved emission behaviour. This project is part of the DFG priority program on photonic crystals.