Core-type polyfluorene-based copolymers for low-cost light-emitting technologies

Single layer white organic light emitting diodes (WOLED) are obtained with a polymeric blend, whose constituents are three polyfluorene (PF) based materials emitting in the three fundamental colours thanks to the insertion of a single monomeric unit with different chemical nature at the core of the PF chain. The peculiar choice of three fully compatible polymers allows us to obtain stable and homogeneous active layers for highly performing WOLEDs. The high quality white electroluminescence with chromaticity coordinates (0.32; 0.33), correlated colour temperature of 5893 K and colour rendering index of 90, makes these compounds good candidates for low-cost solid-state lighting technologies. (C) 2010 Elsevier B. V. All rights reserved.