Polyfluorenes minimally doped with 1,4-bis(2-thienyl-2-cyanovinyl)benzene chromophore: Their synthesis, characterization, and application to white-light-emitting materials

Bar Yuan Hsieh, Yun Chen

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

Copolyfluorenes (PFR1 and PFR2), chemically doped with 0.1 and 0.025 mol % 2,5-dihexyloxy-1,4-bis(2-thienyl-2-cyanovinyl)benzene (MR chromophere) were synthesized by the Suzuki coupling reaction. The PFRs were used to fabricate white-light-emitting devices through incomplete energy transfer. Because of the low content of the MR chromophore, the optical, thermal, and electrochemical properties of the PFRs were almost identical to those of polyfluorene, except for their photoluminescent (PL) and electroluminescent (EL) properties. The copolymer films showed PL peaks at about 428 and 570 nm originating from fluorene segments and MR chromophores, respectively. Compared with the model compound (MR), the polymer chains extended the conjugation length of the MR chromophores and exhibited a 20-48 nm red-shift in the emission band. In addition, the lower LUMO level of the MR (-3.27 eV) was expected to improve the electron injection. The EL devices [ITO/PEDOT:PSS/ PFRs/Ca (50 nm)/Al (100 nm)] showed a broad emission band, covering the entire visible region, with chromaticity coordinates of (0.36, 0.35) and (0.32, 0.30) for PFR1 and PFR2 devices, respectively. The emission color of the PFR2 device was very similar to that of a pure white light (0.33, 0.33); and the maximal brightness and current efficiency were 3011 cd/m2 and 1.98 cd/A, respectively, which surpass those found for polyfluorene devices (1005 cd/m2, 0.28 cd/A).

Original languageEnglish
Pages (from-to)3703-3713
Number of pages11
JournalJournal of Polymer Science, Part A: Polymer Chemistry
Volume46
Issue number11
DOIs
Publication statusPublished - 2008 Jun 1

All Science Journal Classification (ASJC) codes

  • Polymers and Plastics
  • Organic Chemistry
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Polyfluorenes minimally doped with 1,4-bis(2-thienyl-2-cyanovinyl)benzene chromophore: Their synthesis, characterization, and application to white-light-emitting materials'. Together they form a unique fingerprint.

  • Cite this