Beilstein J Org Chem
State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Wushan Road 381, Tianhe District, Guangzhou 510640, Guangdong Province, P. R. China.
Published: March 2018
The design of orange-light emitting, thermally activated, delayed fluorescence (TADF) materials is necessary and important for the development and application of organic light-emitting diodes (OLEDs). Herein, two donor-acceptor-donor (D-A-D)-type orange TADF materials based on fluorenone and acridine, namely 2,7-bis(9,9-dimethylacridin-10(9)-yl)-9-fluoren-9-one (27DACRFT, ) and 3,6-bis(9,9-dimethylacridin-10(9)-yl)-9-fluoren-9-one (36DACRFT, ), were successfully synthetized and characterized. The studies on their structure-property relationship show that the different configurations have a serious effect on the photoluminescence and electroluminescence performance according to the change in singlet-triplet splitting energy (Δ) and excited state geometry. This indicates that a better configuration design can reduce internal conversion and improve triplet exciton utilization of TADF materials. Importantly, OLEDs based on exhibited a maximum external quantum efficiency of 8.9%, which is higher than the theoretical efficiency of the OLEDs based on conventional fluorescent materials.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5870154 | PMC |
http://dx.doi.org/10.3762/bjoc.14.55 | DOI Listing |
Angew Chem Int Ed Engl
January 2025
Shenzhen University, College of Materials Science and Engineering, Xueyuan Avenue, 518000, Shenzhen, CHINA.
The development of pure-green organic emitters with ideal emission peak and ultra-narrow full-widths at half-maximum (FWHMs) remains a formidable challenge. Herein, we report two new green emitters, CNBN and MCNBN, which achieve extremely narrow FWHMs by synergistic rigid π-extension and cyano-substitution for sky-blue multi-resonance thermally activated delayed fluorescence (MR-TADF) core. The introduction of cyano groups induces red-shifts of emission to green region and dramatically minimize the FWHMs.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Institute of Chemistry Chinese Academy of Sciences, CAS Key Laboratory of Molecular Recognition and Function, CHINA.
A pair of axially chiral thermally activated delayed fluorescent (TADF) enantiomers, R-TCBN-ImEtPF6 and S-TCBN-ImEtPF6, with intrinsic ionic characteristics were efficiently synthesized by introducing imidazolium hexafluorophosphate to chiral TADF unit. The TADF imidazolium salts exhibited a high photoluminescence quantum yield (PLQY) of up to 92%, a small singlet-triplet energy gap (∆EST) of 0.04 eV, as well as reversible redox properties.
View Article and Find Full Text PDFChemphyschem
January 2025
South China University of Technology School of Materials Science and Engineering, State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, 381 Wushan Road, 510640, Guangzhou, CHINA.
Multi-resonance thermally activated delayed fluorescence (MR-TADF) materials possess unique advantages of high-efficiency and narrowband emission, which have rapidly occupied an important position in the field of organic light-emitting diodes (OLEDs). In recent years, significant advancements have been made in the development of MR-TADF materials, particularly in achieving spectral narrowing for high-color-purity OLED applications. Based on diverse MR-TADF molecular skeletons, this review summarizes the primary molecular strategies to narrow spectrum by suppressing structural relaxation and intermolecular interactions.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
Mulliken Center for Theoretical Chemistry, Clausius Institute for Physical and Theoretical Chemistry, Rheinische Friedrich-Wilhelms Universität Bonn, Beringstraße 4, 53115 Bonn, Germany.
With their narrow-band emission, high quantum yield, and good chemical stability, multiresonance thermally activated delayed fluorescence (MR-TADF) emitters are promising materials for OLED technology. However, accurately modeling key properties, such as the singlet-triplet (ST) energy gap and fluorescence energy, remains challenging. While time-dependent density functional theory (TD-DFT), the workhorse of computational materials science, suffers from fundamental issues, wave function-based coupled-cluster (CC) approaches, like approximate CC of second-order (CC2), are accurate but suffer from high computational cost and unfavorable scaling with system size.
View Article and Find Full Text PDFAdv Mater
January 2025
Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, P. R. China.
Herein, a parallel "bifunctional group" modulation method is proposed to achieve controlled modulation of the emission wavelength and full-width at half-maximum (FWHM) values. As a result, three proof-of-concept emitters, namely DBNDS-TPh, DBNDS-DFPh, and DBNDS-CNPh, are designed and synthesized, with the first functional dibenzo[b,d]thiophene unit concurrently reducing the bandgap and elevate their triplet state energy. A second functional group 1,1':3',1″-triphenyl, and electron acceptors 1,3-difluorobenzene and benzonitrile, respectively, to deepen the HOMO and LUMO levels.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!
© LitMetric 2025. All rights reserved.