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. 21, 2025
Abstract The preparation of narrow emission bandwidth materials is crucial for the development advanced organic light‐emitting diodes (OLEDs). In this review article, state‐of‐the‐art methodologies used emitters with high color purity are summarized, and favorable design strategies rationally organized. Currently OLEDs have some issues, such as device stabilization that must be resolved, should also considered. Given recent exponential growth in number types narrowband emissive organometallic complexes exhibiting multiple‐resonance thermally activated delayed fluorescence metal‐to‐ligand charge transfer characteristics, there an urgent need to establish key technology descriptors purity. review, developments boron, fused indolocarbazole, carbonyl, phosphine oxide, exhibit spectra described, future directions advance performance devices suggested.
Language: Английский
Citations
1
JACS Au, Journal Year: 2025, Volume and Issue: 5(2), P. 756 - 765
Published: Jan. 23, 2025
Carbazolocarbazole (CCz) represents a novel class of heterocycles in the carbazole family, distinguished by its unique structure and related properties. However, significant challenges associated with synthesis have constrained exploration studies recent years. Herein, we presented thorough reproducible method for synthesizing gram-sized helical CCz, extending functionalization to investigate both pristine CCz six derivatives various substituents. This work is debut compounds displaying afterglow characteristics solid state. The demonstrated impressive ultralong room-temperature phosphorescence (URTP) lifetimes, ranging from 0.52 0.72 s, which are considered relatively long among family. URTP series occurs due efficient intersystem crossing (ISC) process singlet triplet-excited states, facilitated enhanced spin–orbit coupling (SOC). Based on comprehensive investigation seven compounds, proposed strategy elevating photoluminescence quantum yield (PLQY) organic emitters. Notably, most rigid derivatives, SpiroCCz, exhibited highest total PLQY 79.9%, one carbazole-based emitters polymer matrix. Overall, innovative promising candidates applications optoelectronic devices, bioimaging, security printing.
Language: Английский
Citations
0
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
Published: Jan. 1, 2025
Language: Английский
Citations
0
Advanced Optical Materials, Journal Year: 2025, Volume and Issue: unknown
Published: March 4, 2025
Abstract An ultrapure deep‐blue multi‐resonance‐induced thermally activated delayed fluorescence (MR‐TADF) material ( DOB2‐DABNA‐C‐NP ) is synthesized as a promising emitter for organic light‐emitting diodes (OLEDs). The emission color precisely tuned by adopting the asymmetric structure, which modified from previously reported symmetric compounds. Notably, compound exhibits narrowband pure blue at 458 nm with small full width half maximum (FWHM) of 27 nm. In addition, large π‐extended structure enables high rate constants reverse intersystem crossing 8.0 × 10 5 s −1 . Theoretical calculations model compounds indicate that difference in position oxygen atoms significantly affects LUMO energy levels, rationalizing wavelength tuning. OLED employing an FWHM 23 This corresponds to Commission Internationale d’Éclairage (CIE) coordinates (0.137, 0.069), are close requirement emitters defined NTSC and Adobe RGB's standards. device excellent external quantum efficiencies 21.7% 20.8% 1000 cd m −2 , demonstrating highly suppressed efficiency roll‐off.
Language: Английский
Citations
0
Published: Jan. 1, 2025
Citations
0
Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: unknown
Published: July 19, 2024
Abstract Heteroatom‐embedded helical nanographenes (NGs) constitute an important and appealing class of intrinsically chiral materials. In this work, a series B,N‐embedded NGs (BN‐HNGs) bearing azepines was synthesized via stepwise regioselective cyclodehydrogenation. First, the phenyl‐ or nitrogen‐bridged dimers were efficiently clipped into highly congested model compounds 1 2 . Later, controllable Scholl reactions tetraphenyl‐tethered precursor generated 1, 7 8 new C−C bonds, thereby establishing robust method for preparation nonalternant BN‐HNGs with up to 31 fused rings. The bilayer nature unambiguously verified by X‐ray diffraction analysis. chirality transferred stereogenic boron centers upon fluoride coordination, concave‐concave structure comply skeleton. Notably, largest BN‐HNG ( 6 ) spontaneously resolved homochiral 4 helix as molecular spiral staircase during crystallization conglomerate formation at single‐crystal scale. large twisted C ‐symmetric π‐surface dynamic skeleton induced curved might have synergistic effects on self‐recognition enantiomers achieve intriguing spontaneous resolution behavior. chiroptical properties enantiomer further investigated, revealing that had strong response in visible range (400–700 nm).
Language: Английский
Citations
3
ACS Materials Letters, Journal Year: 2025, Volume and Issue: unknown, P. 1896 - 1904
Published: April 16, 2025
Language: Английский
Citations
0
Advanced Optical Materials, Journal Year: 2024, Volume and Issue: unknown
Published: Sept. 9, 2024
Abstract Multiple resonance thermally activated delayed fluorescence (MR‐TADF) emitters are promising for high‐definition organic light‐emitting diodes (OLEDs) due to their high exciton utilization and color purity. However, strong interchromophore interactions cause most MR‐TADF with planar structures aggregate at doping concentrations, leading degraded efficiencies. Herein, using benzenesulfonyl‐functionalized dibenzothiophene sulfoximine steric effects, three (2SBN, 3SBN, 4SBN) synthesized by coupling the classic DtBuCzB skeleton different sites. Three exhibit green or blue‐green emission full width half maximum (FWHM) values less than 29 nm photoluminescence quantum yields exceeding 90%. OLEDs based on 2SBN, 4SBN achieve external efficiency (EQE max ) of 30.1%, 27%, 33.8%, respectively, a 5 wt.% concentration. Notably, distorted conformation suppressed intermolecular interaction, OLED remains EQE 28.9% concentration 20 wt.%. These results demonstrate feasibility molecular design modulate spatial conformations via positional isomerism develop reduced quenching.
Language: Английский
Citations
2
Chemical Science, Journal Year: 2024, Volume and Issue: unknown
Published: Jan. 1, 2024
Spiro-acridine modified N/B/O type MR-TADF emitters realized deep blue fluorescence with an EQE max of 20.5% and CIE (0.147, 0.048), which is state-of-the-art efficiency for deep-blue MR y approaching the BT.2020 standard.
Language: Английский
Citations
2