Excimer formation by electric field induction and side chain motion assistance in polyfluorenes

被引:68
作者
Lu, HH [1 ]
Liu, CY [1 ]
Jen, TH [1 ]
Liao, JL [1 ]
Tseng, HE [1 ]
Huang, CW [1 ]
Hung, MC [1 ]
Chen, SA [1 ]
机构
[1] Natl Tsing Hua Univ, Dept Chem Engn, Hsinchu 30013, Taiwan
关键词
D O I
10.1021/ma051594z
中图分类号
O63 [高分子化学(高聚物)];
学科分类号
070305 ; 080501 ; 081704 ;
摘要
For poly(9,9-di(6-(2-(3-oxetanyl)butoxyl)hexyl)-2,7-fluorene) (POBOHF), measurements on field induction-thermally stimulated current (FI-TSC) and electroluminescence (EL) under a wide temperature range demonstrate that electric field induction (FI) accompanied by side chain motion can lead to a formation of excimers, which contribute to a growth of a green component in the EL spectrum. This phenomenon also happens to poly(9,9-di-n-octyl-2,7-fluorene) (PFO), especially under long-term operations with higher electric fields (1 x 10(6) V/cm), copolymers of OBOHF and FO (PF-1/1 and PF-1/3), and even cross-linked POBOHF. The higher polarity of the side chain in the polyfluorenes (PFs) can cause a more pronounced FI effect. For POBOHF, the green component can even dominate after a few cycles of device operation. Lowering the content of cross-linkable commoner in the copolymers from 50 to 25 mol % only moderately suppresses the formation of FI excimers.
引用
收藏
页码:10829 / 10835
页数:7
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