Related Experiment Video
Updated: Jul 14, 2025
Production and Characterization of Vacuum Deposited Organic Light Emitting Diodes
Published on: November 16, 2018
Alignment of Heptagonal Diimide and Triazine Enables Narrowband Pure-Blue Organic Light-Emitting Diodes with Low
Weiguo Han1, Junjie Liu1, Chunhao Ran1
1Key Laboratory of Green Chemistry, Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, People's Republic of China.
Abstract:
The endeavor to develop high-performance narrowband blue organic light-emitting diodes (OLEDs) with low efficiency roll-off represents an attractive challenge. Herein, we introduce a hetero-acceptor design strategy centered around the heptagonal diimide (BPI) building block to create an efficient thermally activated delayed fluorescence (TADF) sensitizer. The alignment of a twisted BPI unit and a planar diphenyltriazine (TRZ) fragment imparts remarkable exciton dynamic properties to 26tCz-TRZBPI, including a fast radiative decay rate (kR ) of 1.0×107 s-1 and a swift reverse intersystem crossing rate (kRISC ) of 1.8×106 s-1 , complemented by a slow non-radiative decay rate (kNR ) of 6.0×103 s-1 . Consequently, 26tCz-TRZBPI facilitates the fabrication of high-performance narrowband pure-blue TADF-sensitized fluorescence OLEDs (TSF-OLEDs) with a maximum external quantum efficiency (EQEmax ) of 24.3 % and low efficiency roll-off even at a high brightness level of 10000 cd m-2 (EQE10000 : 16.8 %). This showcases a record-breaking external quantum efficiency at a high luminance level of 10000 cd m-2 for narrowband blue TSF-OLEDs.
