Luminescent Copoly(aryl ether)s Consisting of Alternate Emitting and Electron-Transporting Segments Derivatives: Synthesis and Characterization

• Main Authors: Yun-Hao Yu, 余昀澔
• Other Authors: Yun Chen
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/36185182632346997350

碩士 === 國立成功大學 === 化學工程學系碩博士班 === 91 === PLED have attracted much interest in recent years due to their potential application in large-area flat panel displays. To achieve high EL efficiency, it is necessary to balance the injection rates of opposite charges and decrease the barriers of charge injection from the opposite contacts. To achieve balanced charge injection, metal electrode with low work function and additional electron transporting layer have been widely employed. Besides, introducing electron transporting units in polymer structure can also be employed to balance charge injection. In this work, four isolated copolymers including emitting segments (distyrylbenzene derivatives) and electron-transporting segments (1,3,4-oxadiazole derivatives) were synthesized and characterized. The ether spacers limited the π-conjugation length to allow the polymers to emit the fixed light color. The emission and the PL quantum yield of the polymers were dominated by the fluorophores with longer emissive wavelength via energy transfer from electron-transporting segments. The HOM and LUMO energy levels of these polymers have been estimated from their cyclic voltammograms. The electron affinity can be enhanced by introducing isolated electron-transporting segments that lead to charges injection balance. In single layer LED devices [Al/polymers (P1~P5)/ITO glass], incorporation of bis-oxadiazole unit increases the electron affinity and reduces the turn-on electric field better than one oxadiazole unit and the optoelectronic properties were better than P5 without electron-transporting segment. Moreover, incorporation of electron transporting segment in P2 leads to better optoelectronic properties than other methods such as blending and double layer devices.