Berlin 2005 – wissenschaftliches Programm

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SYOO: Organic Optoelectronics and Photonics

SYOO 6: Poster

SYOO 6.57: Poster

Montag, 7. März 2005, 18:00–20:00, Poster TU A

Phosphorescence lifetime measurements of Ir-based phosphorescent dyes in PVK matrix — •Sönke Klinger, Xiao-Hui Yang, Frank Jaiser, and Dieter Neher — University of Potsdam, Am Neuen Palais 10, D-14469 Potsdam, Germany

Most light-emitting diodes based on PVK doped with phosphorescence dyes contain additional carrier-transporting components to improve the electroluminescence performance. We performed phosphorescence lifetime measurements to obtain information on how the phosphorescent dye interacts with these molecules. In particular PVK+Ir(ppy)3 or FIrPic doped with several charge trapping and transporting moieties such as PBD, OXD, TPD were studied with different concentrations of all components. The lifetime of the PVK+FIrPic+PBD sample is much longer than those of PVK+FIrPic and PVK+OXD+FIrPic. At the same time, photoluminescence efficiency of the former sample decreases when the dye is directly excited at 405nm. This can be explained by the fact of poor confinement of the triplet excited state on FIrPic due to the lower triplet energy of PBD. Consistent with lifetime measurements, LEDs with OXD showed much higher efficiency (12-14 cd per A) than that with PBD (4-6 cd per A).