Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5190719 | Polymer | 2005 | 5 Pages |
A blue electroluminescent polymer, random copolymer of fluorenylstilbene and fluorene, was prepared by the nickel catalyzed coupling reaction. The structure and properties of the copolymer were analyzed by various spectroscopic methods. The obtained polymer had good solubility and thermal stability with high Tg. The polymer in thin film emits strong blue luminance (max=468Â nm) with narrow bandwidth upon photoexcitation. PL spectrum of the polymer in the film is almost consistent with that of solution one as well as the EL spectrum, indicating that the aggregation and the excimer fluorescence are suppressed by the introduction of fluorenylstilbene comonomer. Moreover, the introduction of fluorenylstilbene comonomer lowered the oxidation potential to lead feasible hole injection, when the compared with poly(fluorene) homopolymer. The ITO/PEDOT/polymer/LiF/Al device showed the maximum brightness of 3500Â cd/m2 with a turn on voltage of 4.4, the maximum efficiency of 0.878Â lm/W and blue emission with CIE chromaticity coordinates of ((x,y)=(0.17, 0.25)).