Dresden 2011 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
DS: Fachverband Dünne Schichten
DS 42: Poster I: Progress in Micro- and Nanopatterning: Techniques and Applications (jointly with O); Spins in Organic Materials; Ion Interactions with Nano Scale Materials; Organic Electronics and Photovoltaics; Plasmonics and Nanophotonics (jointly with HL and O); High-k and Low-k Dielectrics (jointly with DF); Organic Thin Films; Nanoengineered Thin Films; Layer Deposition Processes; Layer Properties: Electrical, Optical, and Mechanical Properties; Thin Film Characterisation: Structure Analysis and Composition; Application of Thin Films
DS 42.55: Poster
Mittwoch, 16. März 2011, 15:00–17:30, P1
Second-Harmonic Generation Spectroscopy of Magnesium Tetraphenylporphyrin Films — •Jan Metje1,2, Gerhard Lilienkamp1, and Winfried Daum1,2 — 1Institute for Energy Research and Physical Technologies, TU Clausthal, Leibnizstr. 4, 38678 Clausthal-Zellerfeld — 2NTH School for Contacts in Nanosystems
Porphyrins such as magnesium tetraphenylporphyrin (MgTPP) are widely known as energy harvester in biological energy cycles. More recently, their efficient conversion of photonic energy has triggered their use as sensitizers in solar cells. The strong absorption of light by porphyrin molecules in the blue-to-violet spectral range is due to the molecular S0 → S2 excitation which gives rise to so-called Soret bands in absorption experiments. While the spectral position and width of these bands are rather insensitive to a substitution of the central atom (Mg, Zn, 2H), the spectra strongly depend on the local environment of the molecule. In this contribution we report on second-harmonic generation (SHG) experiments performed with MgTPP films evaporated on SiO2 under ultra-high vacuum conditions. SHG spectra of MgTPP films in the spectral range of the Soret band show two bands with energies at 2.94 eV (422 nm) and 2.7 eV (460 nm). The spectral position of the former band agrees with that of individual MgTPP molecules dissolved in solutions whereas the large red shift of the latter band indicates strong intermolecular interactions. Results of SHG experiments with MgTPP films of different thicknesses will be presented to verify the surface and bulk character, respectively, of these molecular excitations.