Azepine Modulation in Thermally Activated Delayed Fluorescence Emitters for OLEDs Achieving Nearly 40% EQE
Year: 2025
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide Thermally activated delayed fluorescence (TADF) emitters play a crucial role in advancing the use of OLED technologies to meet the increasing demands of full-color displays and solid-state lighting. In this work, we present two azepine-pyridine-carbonitrile-based compounds named ISBmPPC and IDBmPPC. Compared to ISBmPPC with a donor iminostilbene (ISB), IDBmPPC with a donor iminodibenzyl (IDB) displays an excellent photoluminescence quantum yield of 95.8%. IDBmPPC with a single bond in a seven-membered nitrogen-containing heterocycle obtains a Δ E ST of 0.03 eV, a reverse intersystem crossing rate of 2.85 × 10 6 s –1, and a horizontal dipole orientation (Θ // ) of 85% in the solid state. Consequently, the IDBmPPC-based OLED device achieved a maximum external quantum efficiency of 39.6%, a maximum current efficiency of 130.1 cd A –1, and a maximum power efficiency of 136.2 lm W –1 with a CIE color coordinate of (0.31, 0.57). This IDB-based molecular design is expected to be applicable to other systems for improving OLED performance.
Source: ACS Materials Letters
Authors: Jian Lei, Yi-Kuan Chen, Min-Jie Wang, Chang-Lun Ko, Wen-Yi Hung, Liang-Yan Hsu, Tien-Lin Wu, Chien-Hong Cheng
Institutions: National Tsing Hua University, Institute of Atomic and Molecular Sciences, Academia Sinica, Chongqing Three Gorges Medical College, Academia Sinica, National Taiwan Ocean University, National Taiwan University, National Center for Theoretical Sciences, National Center for Theoretical Sciences, Physics Division, National Sun Yat-sen University
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
OpenAlex ID: W4409497012