Derivatives of Phenyl Pyrimidine and of the Different Donor Moieties as Emitters for OLEDs

Two derivatives of phenyl pyrimidine as acceptor unit and triphenylamino or 4,4'-dimethoxytriphenylamino donor groups were designed and synthesized as emitters for organic light-emitting diodes (OLEDs) aiming to utilize triplet excitons in the electroluminescence. Thermogravimetric analysis rev...

Full description

Saved in:
Bibliographic Details
Published in:Materials 2024-03, Vol.17 (6), p.1357
Main Authors: Starykov, Hryhorii, Bezvikonnyi, Oleksandr, Leitonas, Karolis, Simokaitiene, Jurate, Volyniuk, Dmytro, Skuodis, Eigirdas, Keruckiene, Rasa, Grazulevicius, Juozas Vidas
Format: Article
Language:English
Subjects:
Charge transfer
Chromatography
Emission
Emitters
Energy
Excitons
Light-emitting diodes
Optoelectronics industry
Organic light emitting diodes
Palladium
Phosphorescence
Potash
Potassium
Pyrimidines
Quantum efficiency
Room temperature
Sodium
Stability analysis
Thermal stability
Thermogravimetric analysis
Weight loss
Citations: Items that this one cites
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Two derivatives of phenyl pyrimidine as acceptor unit and triphenylamino or 4,4'-dimethoxytriphenylamino donor groups were designed and synthesized as emitters for organic light-emitting diodes (OLEDs) aiming to utilize triplet excitons in the electroluminescence. Thermogravimetric analysis revealed high thermal stability of the compounds with 5% weight loss temperatures of 397 and 438 °C. The theoretical estimations and photophysical data show the contributions of local excited and charge transfer states into emission. The addition of the methoxy groups led to the significant improvement of hole-transporting properties and the bathochromic shift of the emission from blue to green-blue spectral diapason. It is shown that mixing of the compounds with the organic host results in facilitation of the delayed emission. The singlet-triplet energy splitting was found to be too big for the thermally activated delayed fluorescence. No thermal activation of the long-lived emission was detected. No experimental evidence for triplet-triplet annihilation and room temperature phosphorescence were detected making the hot exciton mechanism the most probable one. The OLEDs based on the compounds reached the maximum external quantum efficiency of up to 10.6%.
ISSN:1996-1944
1996-1944
DOI:10.3390/ma17061357