Theoretical Insight into Molecular Orientation for Thermally Activated Delayed Fluorescence Emitters in Vacuum Deposition

2021 ◽  
Vol 125 (3) ◽  
pp. 1665-1672
Author(s):  
Kai Ren ◽  
Wanlin Cai ◽  
Rongxing He ◽  
Wei Shen ◽  
Ming Li
Keyword(s):  
Molecular Orientation ◽  
Delayed Fluorescence ◽  
Vacuum Deposition ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Theoretical Insight ◽  
Insight Into

scholarly journals Photoluminescence and Electrochemiluminescence of Thermally Activated Delayed Fluorescence (TADF) Emitters Containing Diphenylphosphine Chalcogenide-Substituted Carbazole Donors

2021 ◽  
Author(s):  
Shiv Kumar ◽  
Pauline Tourneur ◽  
Jonathan Adsetts ◽  
Michael Wong ◽  
Pachaiyappan Rajamalli ◽  
...  
Keyword(s):  
Emission Spectra ◽  
Delayed Fluorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Polar Media ◽  
Delay Times ◽  
Derivatives Of ◽  
Homo Lumo ◽  
Rising Time ◽  
Insight Into

Aiming to develop efficient blue-emitting thermally activated delayed fluorescence (TADF) compounds, we have designed and synthesized derivatives of the well-known sky-blue emitter 2CzPN that contain electron-accepting phosphine chalcogenide groups to stabilize the HOMO level relative to the pristine compound, thus increasing the HOMO-LUMO gap and blue-shifting the emission wavelength. By cyclic voltammetry, photophysical data and quantum-chemical calculations, it was found that polar solvents and matrices validated the proposed concept, but these trends were not recovered in non-polar media. The suitability of these 2CzPN derivatives in polar matrices for optoelectronic applications was explored with electrochemiluminescence (ECL) by measuring emission delays, radical stability, emission stabilities, emission efficiencies and emission spectra. Some of the 2CzPN derivatives showed an unprecedented delayed onset of the ECL, and delayed rising time to the ECL maximum, as well as long ECL emission decay. All of these mentioned delay times suggest that these luminophores primarily emit via organic long-persistent electrochemiluminescence (OLECL) mechanisms. The derivatization of the donor groups of the emitters affected both the radical stability and the predominant emission mechanism, providing important insight into their potential as emitters in solid-state electroluminescent devices.

Extended π-backbone for highly efficient near-infrared thermally activated delayed fluorescence with enhanced horizontal molecular orientation

2022 ◽  
Author(s):  
Jian-Li He ◽  
Yukun Tang ◽  
Kai Zhang ◽  
Yue Zhao ◽  
Yu-Ching Lin ◽  
...  
Keyword(s):  
Molecular Orientation ◽  
Near Infrared ◽  
Delayed Fluorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Highly Efficient ◽  
Donor Acceptor ◽  
Limited Choice

The near-infrared thermally activated delayed fluorescence (NIR-TADF) materials with emission over 700 nm were insufficiently investigated mainly due to the limited choice of strong donor/acceptor units for the molecular construction...

Sign in / Sign up

Export Citation Format

Share Document