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Abstract: In this work organic light emitting devices (OLEDs) were fabricated implementing gratings, in order to extract waveguided electroluminescence (EL). The gratings were recorded by exposing thin films of the molecular azo glass N, N′-bis (4-phenyl)-N, N′-bis [(4-phenylazo)-phenyl] benzidine (AZOPD) to holographic light patterns. The photopatterned AZOPD serves as hole transport material for devices with aluminum-tris(8-hydroxyquinoline) doped with 1% of 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (Alq3:DCM) as emissive/electron transport layer. The corrugated devices showed enhanced emission in the forward direction. The emitted light is polarized preferably parallel to the grating lines. In addition, we have found a doubling in the total luminance with respect to the unstructured device. [Copyright &y& Elsevier]

A detailed analysis of the optical waveguide modes in organic light emitting diodes (OLEDs) is presented. The modes are compared with respect to their electric field profile, attenuation coefficient and optical confinement factor. The first transversal electric (TE) mode is best suited for an optimized energy transfer from emitting dipoles. The transversal magnetic (TM) modes are characterized by a large plasmon character with high absorption. The propagation constants of distinct modes have been measured in test devices by grating coupling. [Copyright &y& Elsevier]