High-efficiency poly(p-phenylenevinylene)-based copolymers containing an oxadiazole pendant group for light-emitting diodes.
High-efficiency poly(p-phenylenevinylene)-based copolymers containing an oxadiazole pendant group for light-emitting diodes.
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DOI：
10.1021/ja036955
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发表时间：
2004-02
影响因子：
15
通讯作者：
Sung‐Ho Jin;Mock-Yeon Kim;J. Y. Kim;Kwanghee Lee;Y. Gal
中科院分区：
文献类型：
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作者：
Sung‐Ho Jin;Mock-Yeon Kim;J. Y. Kim;Kwanghee Lee;Y. Gal
新型高亮度发光效率多晶硅（对亚苯基亚乙烯基）（PPV）基电致发光（EL）聚合物，聚[2-[4-[5-（4-（3，7-二甲基辛氧基）苯基）-1，3，4-恶二唑-2-基]苯氧基]-1，4-亚苯基亚乙烯基]（Oxa-PPV），聚[2-[2-（（3，7-二甲基辛基）氧基）苯氧基]-1，4-亚苯基亚乙烯基]（DMOP-PPV），以及它们相应的无规共聚物，聚[[2-[4-[5-（4-甲基苯基）-2-氧代戊烯-2-基）-2-氧代戊烯-2-基]-2-氧代戊烯-2-基]-2-氧代戊烯-2-氧代戊烯-2-基]-2-氧代戊烯-2-氧代戊烯-（4-（3，7-二甲基辛氧基）苯基）-1，3，4-恶二唑-2-基]苯氧基]-1，4-亚苯基亚乙烯基]-co-[2-[2-通过Gilch聚合法合成了侧基上带有缺电子1，3，4-恶二唑结构单元的[（3，7-二甲基辛基）氧基）苯氧基]-1，4-亚苯基亚乙烯基]]（Oxa-PPV-co-DMOP-PPV）。新设计和合成的Oxa-PPV、DMOP-PPV和Oxa-PPV-co-DMOP-PPV分子结构不对称，在普通有机溶剂中完全溶解，在氧化铟锡（ITO）基底上容易旋涂出无缺陷的光学薄膜。Oxa-PPV显示出高的玻璃化转变温度（T（g）），这可能是聚合物发光二极管（PLED）长时间工作的优势。利用这些聚合物制备了ITO/PEDOT/polymer/Al结构的双层LED。通过在共聚物中引入Oxa-PPV的含量，可以调节共聚物的电光性能和器件性能。通过分子内能量转移，发光颜色可以从绿色调谐到黄橙色。Oxa-PPV相对于DMOP-PPV和Oxa-PPV-co-DMOP-PPV的改进的器件性能可能是由于更好的电子注入和空穴与电子之间的电荷平衡以及从1，3，4-恶二唑单元到PPV主链的有效分子内能量转移。Oxa-PPV的最大亮度和发光效率在14 V时达到19395 cd/m2，在5930 cd/m2时达到21.1 cd/A。Oxa-PPV的最大发光效率是迄今为止PPV衍生物中的最高值。
A new series of high brightness and luminance efficient poly(p-phenylenevinylene) (PPV)-based electroluminescent (EL) polymers, poly[2-[4-[5-(4-(3,7-dimethyloctyloxy)phenyl)-1,3,4-oxadiazole-2-yl]phenyloxy]-1,4-phenylenevinylene] (Oxa-PPV), poly[2-[2-((3,7-dimethyloctyl)oxy)phenoxy]-1,4-phenylenevinylene] (DMOP-PPV), and their corresponding random copolymers, poly[[2-[4-[5-(4-(3,7-dimethyloctyloxy)phenyl)-1,3,4-oxadiazole-2-yl]phenyloxy]-1,4-phenylenevinylene]-co-[2-[2-((3,7-dimethyloctyl)oxy) phenoxy]-1,4-phenylenevinylene]] (Oxa-PPV-co-DMOP-PPV), with an electron-deficient 1,3,4-oxadiazole unit on the side groups, were synthesized through the Gilch polymerization method. The newly designed and synthesized asymmetric molecular structures of Oxa-PPV, DMOP-PPV, and Oxa-PPV-co-DMOP-PPV were completely soluble in common organic solvents, and defect-free optical thin film was easily spin-coated onto the indium tin oxide (ITO) substrate. Oxa-PPV shows a high glass transition temperature (T(g)), which might be an advantage for long time operation of polymer light-emitting diodes (PLEDs). Double-layer LEDs with an ITO/PEDOT/polymer/Al configuration were fabricated by using those polymers. Electrooptical properties and device performance could be adjusted by introducing the Oxa-PPV content in the copolymers. The emission colors could be tuned from green to yellowish-orange via intramolecular energy transfer. The improved device performance of Oxa-PPV over DMOP-PPV and Oxa-PPV-co-DMOP-PPV may be due to better electron injection and charge balance between holes and electrons and also efficient intramolecular energy transfer from 1,3,4-oxadiazole units to PPV backbones. The maximum brightness and the luminance efficiency of Oxa-PPV were up to 19395 cd/m(2) at 14 V and 21.1 cd/A at 5930 cd/m(2). The maximum luminance efficiency of Oxa-PPV is ranked the highest value among the PPV derivatives to date.