Stabilizing color shift of tandem white organic light-emitting diodes

Abstract One drawback of white organic light-emitting diodes (WOLEDs) is the white angular dependence (WAD). Aimed to suppress the WAD of tandem WOLED to a negligible degree, we investigated the effect of optical resonance and probed various scattering structures. In a two-tandem configuration, the emissive layer physically remote from the reflective metal electrode is causing detrimental WAD. By combining an external nanoparticle based volumetric scattering film and an internal random nanostructure, it was possible to suppress the WAD of tandem WOLED to a value as low as 0.005, which is indistinguishable to human eyes.