標題: Synthesis, characterization, and photophysics of electroluminescent fluorene/dibenzothiophene- and fluorene/dibenzothiophene-S,S-dioxide-based main-chain copolymers bearing benzimidazole-based iridium complexes as backbones or dopants
作者: Huang, Wei-Sheng
Wu, Ying-Hsien
Hsu, Ying-Chan
Lin, Hong-Cheu
Lin, Jiann T.
材料科學與工程學系
Department of Materials Science and Engineering
關鍵字: Phosphorescence;Iridium complex;Charge carrier mobilities
公開日期: 27-Nov-2009
摘要: A series of electroluminescent copolymers containing fluorene-2,8-disubstituted dibenzothiophene (PFD), fluorene-2,8-disubstituted dibenzothiophene-SS-dioxide (PFDo) and phosphorescent benzimidazole-based iridium (Ir) complexes in the backbones were synthesized by the Suzuki coupling reaction. The thermal stabilities, HOMO/LUMO levels and triplet energy gap (ET) values were enhanced with increasing contents of dibenzothiophene ( D) or dibenzothiophene-S,S-dioxide (Do) segments in the copolymers. The relative intensities of phosphorescence and fluorescence were affected by the energy transfer and back transfer efficiencies between the polymer backbones and iridium units as evidenced by solid state PL and EL spectra. PLED devices with a configuration of ITO/PEDOT:PSS (50 nm)/metal-free copolymers (P1-P5), Ir-copolymers (P7-P13) and Ir-doped copolymers (P3 doped with Ir-complexes 6 and 8) (60-80 nm)/TPBI (40 nm)/LiF (1 nm)/Al (120 nm) were fabricated, and the electroluminescence (EL) efficiencies depended on the chemical constituents and triplet energies of the copolymers. The space-charge-limited current (SCLC) flow technique was used to measure the charge carrier mobilities of these copolymers, where both hole and electron mobilities were in the following order: the metal-free copolymers (P2, P3 and P5) > Ir-doped copolymers (P3+3 or 10 mol% Ir-complex 6) > Ir-copolymers (P7, P8, P12 and P13). (C) 2009 Elsevier Ltd. All rights reserved.
URI: http://dx.doi.org/10.1016/j.polymer.2009.10.011
http://hdl.handle.net/11536/6408
ISSN: 0032-3861
DOI: 10.1016/j.polymer.2009.10.011
期刊: POLYMER
Volume: 50
Issue: 25
起始頁: 5945
結束頁: 5958
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