New Exciplex‐forming Cohost Systems Harnessing Acceptors With Phenanthrene and Phenanthroline Core for Near‐Infrared OLEDs
Journal
Chemistry – An Asian Journal
ISSN
1861-4728
1861-471X
Date Issued
2025-06-05
Author(s)
Abstract
Two new acceptors, C-BPhCN and N-BPhCN, with 2,3-dicyanopyrazinophenanthrene and pyrazino[2,3-f][1,10]phenanthroline-2,3-dicarbonitrile core and ortho-linked biphenyl peripherals were synthesized and characterized. The exciplex formation of C-BPhCN and N-BPhCN as acceptor (A) and SBFC-G1 as donor (D) was examined. Through optimization, the device using a D:A (2:1) blend in emitting layer (EML) exhibited maximum external quantum efficiency (EQEmax) of 8.26% and 5.25% with electroluminescence peak (EL λmax) centered at 581 and 595 nm, respectively. A new D–A–D configured near-infrared (NIR) fluorescent emitter DMACBBT was introduced as a dopant in the exciplex-forming cohost system. By tuning the thickness of the electron transporting layer (ETL), the EQEmax of the device employing SBFC-G1:C-BPhCN (2:1): 9 wt % DMACBBT as the EML reached 1.03% with EL λmax at 808 nm. The counterpart device utilizing SBFC-G1:N-BPhCN (2:1): 9 wt % DMACBBT as the EML exhibited an EQEmax of 1.01% and EL λmax at 817 nm. The stability of the NIR OLED device was measured, yielding lifetimes (T60) of 182 and 126 h for SBFC-G1:C-BPhCN and SBFC-G1:N-BPhCN cohost-based devices, respectively. This work highlights the high efficiency of NIR OLEDs that can be practically realized by using the exciplex cohost systems with a tailor-made NIR fluorescent emitter.
Subjects
Energy transfer
Exciplex
Intermolecular charge transfer
Near infrared emission
Thermally activated delayed fluorescence
SDGs
Publisher
Wiley
Type
journal article