Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.


Issue 46, 2019
Previous Article Next Article

Blue thermally activated delayed fluorescence emitters incorporating acridan analogues with heavy group 14 elements for high-efficiency doped and non-doped OLEDs

Author affiliations

Abstract

Deep-blue thermally activated delayed fluorescence (TADF) emitters are promising alternatives for conventional fluorescence and phosphorescence materials for practical application in organic light-emitting diodes (OLEDs). However, as appropriate bipolar hosts for deep-blue TADF-OLEDs are scarce, the development of efficient deep-blue TADF emitters that are applicable to both doped and non-doped systems is an urgent task. In this study, we developed a new family of blue TADF emitters that demonstrated high photoluminescence (PL) and electroluminescence (EL) quantum efficiencies in both doped and non-doped (neat) systems. Four new donor–acceptor (D–A)-type TADF molecules incorporating phenazasiline, phenazagermine, and tetramethylcarbazole as weak D units and phenothiaborin as a weak A unit were designed and synthesized. By varying the structural rigidity/flexibility as well as the electron-donating ability of the D units, the resulting photophysical and TADF properties of the D–A molecules could be systematically regulated. A comprehensive photophysical investigation revealed that phenazasiline and phenazagermine-based emitters concurrently exhibit blue TADF emissions (464–483 nm), high PL quantum efficiencies (∼100%), extremely fast spin-converting reverse intersystem crossing rates (>107 s−1), and suppressed concentration quenching. These fascinating features in conjunction produced high-performance doped and non-doped blue TADF-OLEDs. The doped and non-doped TADF-OLEDs using the phenazasiline-based emitter demonstrated extremely high maximum external EL quantum efficiencies (ηext) of 27.6% and 20.9%, with CIE chromaticity coordinates of (0.14, 0.26) and (0.14, 0.20), respectively. Further, ultra-low efficiency roll-off behavior for both the doped and non-doped devices was demonstrated by their ηext as high as 26.1% and 18.2%, respectively, measured at a practically high luminance of 1000 cd m−2.

Graphical abstract: Blue thermally activated delayed fluorescence emitters incorporating acridan analogues with heavy group 14 elements for high-efficiency doped and non-doped OLEDs

Back to tab navigation

Supplementary files

Article information


Submitted
06 Sep 2019
Accepted
21 Oct 2019
First published
29 Oct 2019

This article is Open Access
All publication charges for this article have been paid for by the Royal Society of Chemistry

Chem. Sci., 2019,10, 10687-10697
Article type
Edge Article

Blue thermally activated delayed fluorescence emitters incorporating acridan analogues with heavy group 14 elements for high-efficiency doped and non-doped OLEDs

K. Matsuo and T. Yasuda, Chem. Sci., 2019, 10, 10687
DOI: 10.1039/C9SC04492B

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. Material from this article can be used in other publications provided that the correct acknowledgement is given with the reproduced material.

Reproduced material should be attributed as follows:

  • For reproduction of material from NJC:
    [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the Centre National de la Recherche Scientifique (CNRS) and the RSC.
  • For reproduction of material from PCCP:
    [Original citation] - Published by the PCCP Owner Societies.
  • For reproduction of material from PPS:
    [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the European Society for Photobiology, the European Photochemistry Association, and RSC.
  • For reproduction of material from all other RSC journals:
    [Original citation] - Published by The Royal Society of Chemistry.

Information about reproducing material from RSC articles with different licences is available on our Permission Requests page.


Social activity

Search articles by author

Spotlight

Advertisements