Düsseldorf 2007 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 31: Poster Laserspektroskopie
Q 31.1: Poster
Dienstag, 20. März 2007, 16:30–18:30, Poster C
Photodynamics of OLED Triplet Emitters Ir(ppy)-0.7ex3 and PtOEP — •Ashu Kumar Bansal1, Alfons Penzkofer1, Wolfgang Holzer1, and Taiju Tsuboi2 — 1Institut II - Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany — 2Faculty of Engineering, Kyoto Sangyo University, Kamigamo, Kita-ku, Kyoto 603-8555, Japan
The absorption behaviour and the emission dynamics of the triplet emitters Ir(ppy)-0.7ex3 and PtOEP in the singlet emitters polystyrene (PS) and dicarbazole-biphenyl (CBP) are studied. Thin films are prepared by spin-coating. The host (PS, CBP) - guest (Ir(ppy)-0.7ex3, PtOEP) interaction is investigated. The luminescence behaviour in the case of guest excitation (excitation frequency in transparency region of hosts) is compared with the luminescence behaviour in the case of host excitation (excitation frequency in absorption region of hosts). Efficient host to guest energy transfer is observed. It is thought to be due to Förster-type energy transfer from the excited singlet system of the host to the excited singlet system of the guest [S-0.7ex1(host) + S-0.7ex0(guest) → S-0.7ex0(host) + S-0.7ex1(guest)] followed by singlet - triplet intersystem-crossing in the guest system and subsequent guest phosphorescence emission). Phosphorescence quantum yields of 0.9 for 4 wt-% Ir(ppy)-0.7ex3 in PS and of 0.1 for 4 wt-% PtOEP in PS were obtained.