Berlin 2005 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
SYOO: Organic Optoelectronics and Photonics
SYOO 6: Poster
SYOO 6.50: Poster
Montag, 7. März 2005, 18:00–20:00, Poster TU A
A quantum-chemical study on excited state absorption spectra of perylene derivatives — •K. Schmidt1, D. Beljonne1, J.-L. Brédas1, E. Engel2, K. Leo2, and M. Hoffmann2 — 1School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA — 2Institut für Angewandte Photophysik, Technische Universität Dresden, D-01062 Dresden, www.iapp.de
Analysis of spectroscopic data or absorption-loss-mechanisms at high exciton densities requires detailed knowledge about optical transitions from the lowest exciton states to higher excited states. We consider such transitions in isolated molecules of the widely investigated perylene derivatives 3,4,9,10-perylene-tetracarboxylic dianhydride (PTCDA) and N,N’-dimethylperylene-3,4,9,10-dicarboximide (MePTCDI). A highly correlated quantum chemical method, i.e., intermediate neglect of differential overlap (INDO) multireference double-configuration-interaction (MRD-CI) technique, provides all excited states and the transition dipole moments between them. The excited state absorption spectra calculated for the fully relaxed excited state geometries are compared to experimental transient absorption spectra of matrix isolated molecules. The experimental spectra in the energy range between 1.2 eV and 2.1 eV (onset of linear absorption) can be clearly assigned to the calculated transitions.