White organic light-emitting diodes based on improved polyfluorene derivative

We proposed a white light-emitting diode based on a dendritic polyfluorene derivative poly((9,9-dibutyl-2,7-diiodo-9H-fluorene)trisphenylamine) (PDFA) as blue-green emitter and doped it with a fluorescent dye 4-dicyanomethylene-2-methyl-6-(p-dimethyl-aminostyryl)-4H-pyran (DCM) as red emitter. White light was achieved by the incoherent superposition of blue-green emission produced from PDFA and red emission from DCM. The Commission Internationale d’Énclairage chromaticity coordinates of the devices varied from (0.19, 0.22) to (0.39, 0.55) with the increase of DCM concentration (from 0 to 0.2 wt.%).