Performance of polymer light-emitting diodes with saturated red-emitting poly(fluorine-co-4,7-dithien-2-yl-2,1,3-benzothiadiazole-carbazole or triphenylamine)
三元共聚物饱和红色电致发光研究

Since electron or hole injection is a limiting factor for most electroluminescent polymers, a matching of the work function of cathodes and anodes and the LUMO\HOMO energy level of polymers is one of the important factors for high performance polymer light emitting devices. In this paper, we report the effect of the cathodes on the performance of the device based on saturated red emitter, three-component copolymer poly (fluorine-co-4, 7-dithien-2-yl-2, 1,3-benzothiadiazole-carbazole or triphenylamine) copolymers. By thermal deposition in combination with spin-coating of electron injection layer, we investigated the influence of various cathode meterials with different ionization potentials in order to optimize the balance of the electron and hole injection. The external quantum efficiency reached 1.49% with luminance 466cd/m2,the EL spectrum peak is located at 657nm with the color coordinate: x=0.69, y=0.30 for PFO-5Cz-15DBT.