Blue Polarized Electroluminescence from a Liquid Crystalline Polyfluorene

Highly polarized electroluminescence from a liquid-crystal polymer device, based on a branched polyfluorene with a branched side chain, is demonstrated here as a further step towards the use of organic electroluminescent (EL) devices as backlights in conventional liquid-crystal displays. The modification of a polyimide (PI) for hole conduction by addition of a suitable filler at moderate concentration is reported and the performance of a device containing such a rubbed, hole-conductor-filled PI layer as the alignment layer is compared with that of a device with a PI-only alignment layer.