Achieving 21% External Quantum Efficiency for Nondoped Solution-Processed Sky-Blue Thermally Activated Delayed Fluorescence OLEDs by Means of Multi-(Donor/Acceptor) Emitter with Through-Space/-Bond Charge Transfer

© 2020 The Authors. Published by WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim..

Although numerous thermally activated delayed fluorescence (TADF) organic light-emitting diodes (OLEDs) have been demonstrated, efficient blue or even sky-blue TADF-based nondoped solution-processed devices are still very rare. Herein, through-space charge transfer (TSCT) and through-bond charge transfer (TBCT) effects are skillfully incorporated, as well as the multi-(donor/acceptor) characteristic, into one molecule. The former allows this material to show small singlet-triplet energy splitting (ΔE ST) and a high transition dipole moment. The latter, on the one hand, further lights up multichannel reverse intersystem crossing (RISC) to increase triplet exciton utilization via degenerating molecular orbitals. On the other hand, the nature of the molecular twisted structure effectively suppresses intermolecular packing to obtain high photoluminescence quantum yield (PLQY) in neat flims. Consequently, using this design strategy, T-CNDF-T-tCz containing three donor and three acceptor units, successfully realizes a small ΔE ST (≈0.03 eV) and a high PLQY (≈0.76) at the same time; hence the nondoped solution-processed sky-blue TADF-OLED displays record-breaking efficiency among the solution process-based nondoped sky-blue OLEDs, with high brightness over 5200 cd m-2 and external quantum efficiency up to 21.0%.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:7

Enthalten in:

Advanced science (Weinheim, Baden-Wurttemberg, Germany) - 7(2020), 7 vom: 09. Apr., Seite 1902087

Sprache:

Englisch

Beteiligte Personen:

Zheng, Xujun [VerfasserIn]
Huang, Rongjuan [VerfasserIn]
Zhong, Cheng [VerfasserIn]
Xie, Guohua [VerfasserIn]
Ning, Weimin [VerfasserIn]
Huang, Manli [VerfasserIn]
Ni, Fan [VerfasserIn]
Dias, Fernando B [VerfasserIn]
Yang, Chuluo [VerfasserIn]

Links:

Volltext

Themen:

Journal Article
Multi‐(donor/acceptor)
Nondoped solution‐processed OLEDs
Sky‐blue
Thermally activated delayed fluorescence
Through‐space/‐bond charge transfer

Anmerkungen:

Date Revised 13.11.2023

published: Electronic-eCollection

Citation Status PubMed-not-MEDLINE

doi:

10.1002/advs.201902087

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM308594398