Blue OLEDs with narrow bandwidth using CF3 substituted bis((carbazol-9-yl)phenyl)amines as emitters: Structural regulation of linker between donor and acceptor in chromophores

Longzhi Zhu, Hongyang Zhang, Xiao Peng, Miao Zhang, Feifan Zhou, Shuming Chen, Jun Song, Junle Qu, Wai Yeung Wong

Research output: Journal article publicationJournal articleAcademic researchpeer-review

Abstract

Three new donor-acceptor (D-A) chromophores decorated with bis(trifluoromethyl)-substituted phenyl group as acceptor and bis(4-(9H-carbazol-9-yl)phenyl)amine as donor unit, namely 1,4-naphthyl-CF3 (1), 1,5-naphthyl-CF3 (2) and Ph-CF3 (3), were designed and synthesized. Their photophysical and electrochemical characteristics, and corresponding theoretical calculations were investigated. They showed blue emissions with high photoluminescence quantum yields (PLQY). Doped organic light-emitting diodes (OLEDs) based on them were fabricated, which exhibited strong blue electroluminescence with emission peaks at 453, 446 and 440 nm and full width at half maximum (FWHM) of 69, 65 and 65 nm, respectively. Their Commission International del'Eclairage (CIE) coordinates correspond to (0.169, 0.158), (0.176, 0.134) and (0.163, 0.099). Besides, the maximum current efficiencies (CEs) of 2.8, 5.0 and 4.9 cd A−1; power efficiencies (PEs) of 2.9, 5.4 and 5.2 lm W−1; external quantum efficiencies (EQEs) of 2.3, 2.3 and 3.4% were achieved for 1,4-naphthyl-CF3 (1), 1,5-naphthyl-CF3 (2) and Ph-CF3 (3) doped devices D1, D2 and D3, respectively. This study clearly showed that the optoelectronic properties of these organic small molecules can be regulated by rational design of molecular structures, and their emission wavelengths could be finely tuned within the blue region.

Original languageEnglish
Article number109627
JournalDyes and Pigments
Volume194
DOIs
Publication statusPublished - Oct 2021

Keywords

  • Blue OLEDs
  • Donor-acceptor structures
  • Narrow bandwidth
  • Structural regulation

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Process Chemistry and Technology

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