Cover Picture: Electronic Excitation Energy Migration in a Photonic Dye–Zeolite Antenna (ChemPhysChem 6/2003)

The cover picture shows a zeolite L crystal containing organized dye molecules that act as donors (green) and acceptors (red). The confocal fluorescence microscopy images of a cylindrical crystal, seen after selective excitation of the green dyes, visualize the organization of the donors and acceptors. These crystals behave as photonic antenna, in which excitation energy is transported by a Förster‐type mechanism until it reaches the acceptor, where the energy is emitted as red luminescence. The intensity decrease is faster in the presence of acceptors (solid green curve) than in their absence (dashed). But the main characteristic of the time evolution of the crystals is that the acceptor intensity is first built up before it starts to decay. Find out more in the article by Calzaferri et al. on pages 567–587.