Regensburg 2010 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 8: Organic Electronics and Photovoltaics I (Joint Session with DS/CPP/O)

HL 8.3: Talk

Monday, March 22, 2010, 10:45–11:00, H8

Analysis of Chemical Degradation Mechanism of Phosphorescent Organic Light Emitting Devices by Laser-Desorption/Ionization Time-of-Flight Mass Spectrometry — •Ines Rabelo de Moraes, Sebastian Scholz, Björn Lüssem, and Karl Leo — Institut für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Str. 1, 01062 Dresden, Germany

Phosphorescent Organic Light Emitting diodes (OLEDs) have attracted much interest for their potential application in full color flat-panel displays and as an alternative lighting source. However, low efficiency, and the short operation lifetime, in particular in the case of blue emitting devices, are the major limitations for the current OLEDs commercialization. In order to overcome these limitations, a deep knowledge about the aging and the degradation mechanism is required [1]. Our work focuses on the chemical degradation mechanism of different iridium based emitter materials like FIrpic (light blue) and Ir(ppy)3 (green), commonly used in OLEDs. For this purpose, the devices were aged by electrical driving until the luminance reached 6% of the initial luminance. The laser-desorption/ionization time-of-flight mass spectrometry was used to determine specific degradation pathways.

[1] Hany Aziz, and Zoran D. Popovic, Chem. Mater. 16, 4522 (2004).