Aryl-Annulated [3,2- a] Carbazole-Based Deep-Blue Soluble Emitters for High-Efficiency Solution-Processed Thermally Activated Delayed Fluorescence Organic Light-Emitting Diodes with CIE y <0.1

Jinhyo Hwang, Chang Woo Koh, Jung Min Ha, Han Young Woo, Sungnam Park, Min Ju Cho, Dong Hoon Choi

Research output: Contribution to journalArticlepeer-review

24 Citations (Scopus)

Abstract

In this study, we demonstrated two deep-blue TADF emitters, BO-tCzPhICz and BO-tCzDICz, for solution-processable thermally activated delayed fluorescence organic light-emitting diodes (TADF-OLEDs). They were synthesized by employing an organoboron acceptor and 9-(3,6-di-tert-butyl-9H-carbazol-9-yl)-5-phenyl-5,12-dihydroindolo[3,2-a]carbazole (tCzPhICz) and 12-(3,6-di-tert-butyl-9H-carbazol-9-yl)-15H-diindolo[2,3-b:1′,2′,3′-lm]carbazole (tCzDICz) as bulky aryl-annulated [3,2-a] carbazole donors, respectively. Both emitters showed sufficient solubility in organic solvents, narrow deep-blue emission, and small energy difference (ΔEST) between singlet and triplet states, which can be applied to solution-processable deep-blue TADF-OLEDs. Solution-processed OLEDs exploiting these TADF emitters displayed deep-blue electroluminescence with CIEy <0.1, and high external quantum efficiencies of 17.8 and 14.8% were observed for BO-tCzPhICz and BO-tCzDICz, respectively. The emitter bearing bulky ICz-based donating units shows highly promising potential for high-efficiency solution-processable deep-blue TADF-OLEDs.

Original languageEnglish
Pages (from-to)61454-61462
Number of pages9
JournalACS Applied Materials and Interfaces
Volume13
Issue number51
DOIs
Publication statusPublished - 2021 Dec 29

Bibliographical note

Funding Information:
This work was supported by the National Research Foundation of Korea (NRF2019R1A2C2002647 and NRF2019R1A6A1A11044070) and LG Display Co. Limited (Q1830291). The authors acknowledge the Institute for Basic Science (IBS, Korea) for allowing us to obtain nuclear magnetic resonance data (NMR; Ascend 500, Bruker).

Publisher Copyright:
© 2021 American Chemical Society.

Keywords

  • deep-blue emitter
  • donor engineering
  • organic light-emitting diode
  • solution-process
  • thermally activated delayed fluorescence

ASJC Scopus subject areas

  • General Materials Science

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