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Unlike boron, nitrogen-containing multi-resonance emitters with thermally activated delayed fluorescence, here we report boron, sulfur (B, S)-based multi-resonance emitters with room-temperature phosphorescence (RTP) by inserting thiophene into a 5,9-dithia-13-boranaphtho[3,2,1-]anthracene skeleton that simultaneously realizes large singlet-triplet energy splitting and strong spin-orbital coupling, leading to efficient room-temperature phosphorescence in an amorphous state. Unlike most RTP emitters with ultraviolet excitation, the multi-resonance RTP emitters exhibit strong phosphorescence under daily-use blue/white LED lamps owing to their intense absorption in the visible-light region (400-486 nm). Meanwhile, such RTP behavior can be tuned by the number and fusing pattern of the thiophene moieties, with the emitters containing thiophene linked to boron atoms α-positions exhibiting bathochromatically shifted emissions and longer phosphorescence lifetimes (47.7-119.4 ms) than those with β-position linkages. Given these features, amorphous RTP films with different emission colors and lifetimes are fabricated by dispersing the emitters in a poly(methyl methacrylate) matrix, and their applications in multi-color anti-counterfeiting are presented. These findings thus open a way to develop multi-resonance emitters as a new family of pure organic RTP materials that can work in an amorphous state and under visible-light excitation.
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http://dx.doi.org/10.1039/d4sc05383d | DOI Listing |
Phys Chem Chem Phys
September 2025
Institute of Physical Chemistry, RWTH Aachen University, 52074 Aachen, Germany.
This work investigates the performance of the density functional theory multireference configuration interaction (DFT/MRCI) method for the donor-acceptor and multi-resonance thermally activated delayed fluorescence (TADF) emitters of the recent STGABS27 benchmark set [L. Kunze, A. Hansen, S.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
August 2025
Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P.R. China.
The organic light-emitting diode (OLED) performance of multi-resonance thermally activated delayed fluorescence (MR-TADF) emitters is fundamentally constrained by their slow reverse intersystem crossing (RISC) and pronounced aggregation-caused quenching (ACQ). Herein, through regioselective borylation, we design and synthesize a series of blue MR-TADF emitters. The regioisomerization-directed twist configuration synergistically enhances RISC while suppressing ACQ, without compromising spectral purity.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
August 2025
Organic Optoelectronic Device Lab. (OODL), Department of Information Display, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea.
The development of efficient and stable ultra-narrowband pure-blue multi-resonance thermally activated delayed fluorescence (MR-TADF) emitters is critical for next-generation wide-gamut OLED displays. Herein, we present a molecular design strategy that enhances emitter stability and efficiency by reinforcing the weak C─N bonds through selective incorporation of heterocyclic carbazole (Cz) units into the MR framework. Two proof-of-concept emitters, m-Cz-DABNA and tBu-Cz-DABNA, were synthesized via high-yield, lithium-free borylation.
View Article and Find Full Text PDFAdv Mater
August 2025
Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China.
Blue-emitting multiple-resonance thermally activated delayed fluorescence (MR-TADF) emitters with high photoluminescence quantum yield (PLQY), high robustness with short-lived emission lifetime is particularly desired for the development of organic light-emitting diodes (OLEDs). In this study, a series of MR-TADF molecules featuring fused boron/nitrogen (B/N) and C ═ O/N frameworks is reported. These emitters namely BNO, BNDO, and BNTO are systematically designed and synthesized to investigate the impact of molecular rigidity or planarity toward their excited-state dynamics through stepwise intramolecular electrophilic acylation reactions.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
August 2025
State Key Laboratory of Supramolecular Structure and Materials, Department of Chemistry, Jilin University, Changchun, 130012, P.R. China.
Strategies that produce OLEDs that simultaneously achieve outstanding electroluminescence efficiency, small efficiency roll-off, good stability, and high color purity remain in strong demand. Herein, we report how judicious decoration of a benzochalcogenophene onto the BCzBN core leads to an acceleration of reverse intersystem crossing (k) without sacrificing either color fidelity and photoluminescence quantum yield (Φ). Compared with BCzBN, the k of BN-S and BN-Se are accelerated to 2.
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