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CPP: Chemische Physik und Polymerphysik

CPP 23: POSTER Functional Organic Thin Films

CPP 23.36: Poster

Donnerstag, 30. März 2006, 17:00–19:00, P2

Distributed Feedback Structures in active OLED-Layers by Photolithography — •Matthias de la Rosa, Klaus Meerholz, and Jonas Kremer — Physical Chemistry Department II, Luxemburgerstr. 116, 50939 Köln

Waveguide losses often result in poor external efficiencies with thin-film organic light emitting diodes (OLEDs). Among other approaches distributed feedback (DFB) structures have been used to overcome this problem by applying additional structured layers underneath the emissive layers in the device. Correct choice of the DFB structure properties like amplitude and period of the grating can lead to enhanced directed emission. Furthermore, such periodic modulations are of great importance in amplified spontaneous emission (ASE) applications like organic polymer lasers. We introduced a lithographic pathway of direct structuring to the OLED fabrication process using cross-linkable emitter and hole-transport materials, respectively. The impact of the DFB gratings onto the performance and spectral emission of the OLEDs was examined and an increase in the efficiency [Cd/A] by a factor of 1.5 could be observed whilst the emission spectra of the corrugated devices hardly changed. Other experiments with DFB structures in ASE materials are in progress to achieve better understanding for further organic polymer laser applications.