Narrowband Near-Infrared Multiple-Resonance Thermally Activated Delayed Fluorescence Emitters towards High-Performance and Stable Organic Light-Emitting Diodes.
Angew Chem Int Ed Engl
; 63(7): e202318433, 2024 Feb 12.
Article
in En
| MEDLINE
| ID: mdl-38148704
ABSTRACT
Multiple-resonance thermally activated delayed fluorescence (MR-TADF) materials are highly coveted for their high efficiency and narrowband emission in organic light-emitting diodes (OLEDs). Nevertheless, the development of near-infrared (NIR) MR-TADF emitters remains a formidable challenge. In this study, we design two new NIR MR-TADF emitters, PXZ-R-BN and BCz-R-BN, by embedding 10H-phenoxazine (PXZ) and 7H-dibenzo[c,g]carbazole (BCz) fragments to increase the electron-donating ability or extending π-conjugation on the framework of para-boron fusing polycyclic aromatic hydrocarbons (PAHs). Both compounds emit in the NIR region, with a full-width at half-maximum (FWHM) of 49â
nm (0.13â
eV) for PXZ-R-BN and 43â
nm (0.11â
eV) for BCz-R-BN in toluene. To sensitize the two NIR MR-TADF emitters in OLEDs, a new platinum complex, Pt-1, is designed as a sensitizer. The PXZ-R-BN-based sensitized OLEDs achieve a maximum external quantum efficiency (EQEmax ) of nearly 30 % with an emission band at 693â
nm, and exceptional long operational stability with an LT97 (time to 97 % of the initial luminance) value of 39084â
h at an initial radiance of 1000â
mW sr-1 m-2 . The BCz-R-BN-based OLEDs reach EQEmax values of 24.2 % with an emission band at 713â
nm, which sets a record value for NIR OLEDs with emission bands beyond 700â
nm.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Angew Chem Int Ed Engl
/
Angew. Chem. (Int. ed., Internet)
/
Angewandte Chemie (International ed. Internet)
Year:
2024
Document type:
Article
Country of publication:
Alemania