Electrical and Optical Properties of WOLEDs with a Hybrid EML Consisting of Small Molecules

Abstract

White organic light-emitting devices (WOLEDs) with a hybrid emitting layer (EML) consisting of blue-emitting small molecules and porous red-emitting polymers formed in a blended polymer layer by utilizing a phase separation process were fabricated. The hole injection efficiency from the hole injection layer to the blue EML was improved due to the formation of a partially connected junction between the hole injection layer and the blue EML. The spin-coating speed for the formation of a porous red-emitting polymer layer was optimized on the basis of the electroluminescence spectra for the WOLEDs and the atomic force microscopy images for the surface of the porous polymer layer. (C) 2011 The Electrochemical Society.