Fluorene-Based Copolymers Containing Dinaphtho-s-indacene as New Building Blocks for High-Efficiency and Color-Stable Blue LEDs
✍ Scribed by Xin Guo; Yanxiang Cheng; Zhiyuan Xie; Yanhou Geng; Lixiang Wang; Xiabin Jing; Fosong Wang
- Book ID
- 102943076
- Publisher
- John Wiley and Sons
- Year
- 2009
- Tongue
- English
- Weight
- 719 KB
- Volume
- 30
- Category
- Article
- ISSN
- 1022-1336
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✦ Synopsis
Abstract
By incorporating a new building block, 7,7,15,15‐tetraoctyldinaphtho‐s‐indacene (NSI), into the backbone of poly(9,9‐dioctylfluorene) (PFO), a novel series of blue light‐emitting copolymers (PFO‐NSI) have been developed. The insertion of the NSI unit into the PFO backbone leads to the increase of local effective conjugation length, to form low‐energy fluorene–NSI–fluorene (FNF) segments that serve as exciton trapping sites, to which the energy transfers from the high‐energy PFO segments. This causes these copolymers to show red‐shifted emissions compared with PFO, with a high efficiency and good color stability and purity. The best device performance with a luminance efficiency of 3.43 cd · A^−1^, a maximum brightness of 6 539 cd · m^−2^, and CIE coordinates of (0.152, 0.164) was achieved.
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