Chemical Engineering Journal, Journal Year: 2024, Volume and Issue: unknown, P. 158958 - 158958
Published: Dec. 1, 2024
Language: Английский
Advanced Optical Materials, Journal Year: 2025, Volume and Issue: unknown
Published: Feb. 8, 2025
Abstract Organic light‐emitting diodes (OLEDs) exhibit significant advantages in the fields of ultra‐high‐definition (UHD) displays and wearable devices. However, developing low‐cost, high‐efficiency, high‐purity blue emission materials remains a challenge for academia industry. While thermally activated delayed fluorescence (TADF) meet low‐cost manufacturing needs achieve 100% internal quantum efficiency, their charge‐transfer excited states lead to broad spectra that don't BT.2020 standard. Fortunately, multiple resonance (MR) strategy offers an effective solution creating TADF with high color purity. Through careful structural design precise tuning state energy levels, MR‐TADF can easily full‐width at half‐maximum (FWHM) less than 30 nm. Nevertheless, it still faces challenges, such as severe aggregation‐induced quenching efficiency roll‐off. Herein, this work overviews recent progress devices, introduce representative molecular strategies aimed suppressing concentration quenching, enhancing reverse intersystem crossing rates, achieving deep emission, which will aid future endeavors develop more efficient, stable devices suitable UHD display applications.
Language: Английский
Citations
1
Chem, Journal Year: 2024, Volume and Issue: unknown
Published: Nov. 1, 2024
Language: Английский
Citations
4
Advanced Optical Materials, Journal Year: 2025, Volume and Issue: unknown
Published: Feb. 5, 2025
Abstract Introducing heavy atoms to enhance spin‐orbit coupling represents an effective strategy for boosting the reverse intersystem crossing (RISC) rate constants of Multi‐resonance thermally activated delayed fluorescence (MR‐TADF) emitters. Nevertheless, restricted diversity molecular structures obstructs a thorough investigation structure‐property relationships, thereby limiting improvement device performance, especially in case solution‐processed devices. Herein, alkylthio‐substituted carbazole building block is designed and developed two new MR‐TADF emitters, namely BNCz‐2S BNCz‐4S. Quantum simulations photophysical studies have revealed that as number sulfur increases, BNCz‐4S exhibits higher photoluminescence quantum yield (PLQY), smaller singlet‐triplet energy gap (Δ E ST ) reorganization energy, along with larger (SOC) constant ( k RISC compared BNCz‐2S. Consequently, solution‐processing devices based on exhibit external efficiency (EQE) 24.06%, which first tier reported organic light‐emitting diodes (OLED) date.
Language: Английский
Citations
0
ACS Materials Letters, Journal Year: 2025, Volume and Issue: unknown, P. 876 - 883
Published: Feb. 6, 2025
Language: Английский
Citations
0
Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown
Published: Feb. 26, 2025
Cycloarenes and heterocycloarenes, characterized by fused macrocyclic π-conjugated structures, hold significant promise in synthetic chemistry materials science. However, their further development remains constrained formidable challenges, particularly for those with contracted cavities. Inspired advances the synthesis of organoboron-based multiresonance thermally activated delayed fluorescence (TADF) emitters, we herein report convenient access detailed characterization a 1,4-azaborine-embedded cycloarene that features smallest cavity among known (hetero)cycloarenes. The induces bowl-shaped molecular geometry, as confirmed crystallographic analysis, while also triggering through-space conjugation delocalized π-electrons at site. Comparative studies between this compound its helical analogue reveal substantial topological impact on photophysical properties, including bathochromic-shifted broadened emission band, prolonged radiative decay process, more efficient triplet-to-singlet spin-flip. Capitalizing TADF remarkably high quantum yield, successfully fabricated first (hetero)cycloarene-based organic light-emitting diodes, achieving over 30% external efficiency minimal roll-off. These findings offer new insights into design topologically distinct compounds unique properties.
Language: Английский
Citations
0
Dyes and Pigments, Journal Year: 2025, Volume and Issue: unknown, P. 112752 - 112752
Published: March 1, 2025
Language: Английский
Citations
0
ACS Catalysis, Journal Year: 2025, Volume and Issue: unknown, P. 5694 - 5705
Published: March 24, 2025
Metal-loaded COF-based photocatalysts facilitate the conversion of CO2 and H2O into storable fuels through a photosynthesis-like mechanism, providing an efficient approach to addressing energy challenges. However, fundamental principles governing internal transfer reaction pathways remain insufficiently understood, posing significant barriers achieving photocatalytic reactions with high selectivity specificity. This study explores heavy-atom effect Pt on exciton-mediated by synthesizing single-atom dispersed PtSA-CTF nanoparticle-aggregated PtNP-CTF defective CTF substrates, thereby revealing selective preferences species their impact pathways. By combining exciton behavior characterization (fs-TA), photoreaction pathway validation (13CO2 isotope labeling) excited-state theoretical calculations (TD-DFT), it was demonstrated that excitons in undergo resonance intermediate during relaxation process from triplet state ground state. The *CO2 then reacts sequentially generated electrons protons, resulting performance CO yield 6.778 mmol·g–1·h–1, 98.2% selectivity, TOF 1102.68 h–1. work provides valuable insights photophysical properties induced excitonic effects, offering guidance for improving efficiency rational design advanced photocatalysts.
Language: Английский
Citations
0
Advanced Functional Materials, Journal Year: 2025, Volume and Issue: unknown
Published: April 21, 2025
Abstract This study explores the impact of regioisomerism a heavy chalcogen atom on photophysical properties multi‐resonant thermally activated delayed fluorescence (MR‐TADF) materials. Two pairs isomeric MR‐TADF emitters containing different benzothienocarbazole moieties, tDPABT1B/tDPABT2B and tCzBT1B/tCzBT2B, are synthesized. Theoretical calculations indicate that tDPABT2B tCzBT2B possess higher spin–orbital coupling values (0.27 0.60 cm⁻¹) compared to their respective isomers. The reveals have twofold faster reverse intersystem crossing rate constants 0.5 × 10⁵ 2.7 s⁻¹, respectively, than counterparts. sensitizer‐free organic light‐emitting diodes (OLEDs) with tCzBT1B exhibit green emissions [CIE coordinates (0.12, 0.54)] show high maximum external quantum efficiencies (EQE max ) 34.9 34.3%, respectively. Notably, device demonstrates reduced efficiency roll‐off (34% decrease at 1000 cd cm⁻ 2 (48% ), highlighting distinct benefits importance regiochemistry in contributing an enhancing performance.
Language: Английский
Citations
0
Chemical Reviews, Journal Year: 2025, Volume and Issue: unknown
Published: May 9, 2025
Fluorescence emitters with a multiple-resonant (MR) effect have become research hotspot. These MR mainly consist of polycyclic aromatic hydrocarbons boron/nitrogen, nitrogen/carbonyl, and indolocarbazole frameworks. The staggered arrangement the highest occupied molecular orbital lowest unoccupied facilitates MR, resulting in smaller internal reorganization energy narrower emission bandwidth. Optimal charge separation suppresses gap between singlet triplet excited states, favoring thermally activated delayed fluorescence (TADF). MR-TADF materials, due to color purity high efficiency, are excellent candidates for organic light-emitting diodes. Nevertheless, significant challenges remain; particular, limitation imposed by alternated core configuration hinders their diversity versatility. Most existing materials concentrated blue-green range, only few red near-infrared spectra. This review provides timely comprehensive screening from pioneering work present. Our goal is gain understandings structure-performance relationship both basic advanced perspectives. Special emphasis placed on exploring correlations chemical structure, photophysical properties electroluminescent performance depth breadth an aim promote future development emitters.
Language: Английский
Citations
0
The Journal of Physical Chemistry C, Journal Year: 2024, Volume and Issue: 128(34), P. 14538 - 14545
Published: Aug. 15, 2024
Significant achievements have been demonstrated with thermally activated delayed fluorescence (TADF) emitters through a spatial charge transfer (TSCT). However, due to the difficulty in synthesis, introducing multiple donor/acceptor units into TSCT-TADF remains continuous challenge. This work proposed material acceptor/donor/acceptor (A/D/A) structure based on 10,12-dihydroindeno[2,1-b]fluorene (indenofluorene) framework, named DSTO. We also synthesized molecule an A/D for comparison, STO. The introduction of acceptors effectively modulates excited-state properties, achieving rapid reverse intersystem crossing process rate 7.1 × 105 s–1. OLED device DSTO as emitter shows maximum external quantum efficiency (EQEmax) around 20%. study broadens design materials and deepens our further understanding structure–property relationship.
Language: Английский
Citations
3