Thermally Activated Delayed Fluorescent Dendrimers that Underpin High-Efficiency Host-Free Solution-Processed Organic Light-Emitting Diodes

Thermally Activated Delayed Fluorescent Dendrimers that Underpin High-Efficiency Host-Free Solution-Processed Organic Light-Emitting Diodes

© 2022 The Authors. Advanced Materials published by Wiley-VCH GmbH.

Bibliographische Detailangaben
Veröffentlicht in:Advanced materials (Deerfield Beach, Fla.). - 1998. - 34(2022), 23 vom: 01. Juni, Seite e2110344
1. Verfasser: Sun, Dianming (VerfasserIn)
Weitere Verfasser: Duda, Eimantas, Fan, Xiaochun, Saxena, Rishabh, Zhang, Ming, Bagnich, Sergey, Zhang, Xiaohong, Köhler, Anna, Zysman-Colman, Eli
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2022
Zugriff auf das übergeordnete Werk:Advanced materials (Deerfield Beach, Fla.)
Schlagworte:Journal Article carbazole external quantum efficiency host-free organic light-emitting diodes solution-processing thermally activated delayed fluorescence dendrimers
Beschreibung
Zusammenfassung:© 2022 The Authors. Advanced Materials published by Wiley-VCH GmbH.
The development of high-performance solution-processed organic light-emitting diodes (OLEDs) remains a challenge. An effective solution, highlighted in this work, is to use highly efficient thermally activated delayed fluorescence (TADF) dendrimers as emitters. Here, the design, synthesis, density functional theory (DFT) modeling, and photophysics of three triazine-based dendrimers, tBuCz2pTRZ, tBuCz2mTRZ, and tBuCz2m2pTRZ, is reported, which resolve the conflicting requirements of achieving simultaneously a small ΔEST and a large oscillator strength by incorporating both meta- and para-connected donor dendrons about a central triazine acceptor. The solution-processed OLED containing a host-free emitting layer exhibits an excellent maximum external quantum efficiency (EQEmax ) of 28.7%, a current efficiency of 98.8 cd A-1 , and a power efficiency of 91.3 lm W-1 . The device emits with an electroluminescence maximum, λEL , of 540 nm and Commission International de l'Éclairage (CIE) color coordinates of (0.37, 0.57). This represents the most efficient host-free solution-processed OLED reported to date. Further optimization directed at improving the charge balance within the device results in an emissive layer containing 30 wt% OXD-7, which leads to an OLED with the similar EQEmax of 28.4% but showing a significantly improved efficiency rolloff where the EQE remains high at 22.7% at a luminance of 500 cd m-2
Beschreibung:Date Revised 09.06.2022
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1521-4095
DOI:10.1002/adma.202110344