Organoboron-based multiple-resonance emitters: synthesis, structure–property correlations, and prospects

Chemical Society Reviews, Journal Year: 2024, Volume and Issue: 53(3), P. 1624 - 1692

Published: Jan. 1, 2024

This review highlights organoboron-based multiple-resonance compounds’ synthetic strategies classified as one-pot borylation, one-shot and late-stage functionalisation, explores material structure–photophysical property correlations.

Language: Английский

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High‐Performance Multi‐Resonance Thermally Activated Delayed Fluorescence Emitters for Narrowband Organic Light‐Emitting Diodes

Advanced Functional Materials, Journal Year: 2023, Volume and Issue: 33(50)

Published: Aug. 7, 2023

Abstract Multi‐resonance thermally activated delayed fluorescence (MR‐TADF) emitters have drawn considerable attention because of their remarkable optoelectronic properties high emission efficiency and narrow profile, represent an active subject cutting‐edge research in the organic electroluminescence (EL). However, slow reverse intersystem crossing (RISC) rate MR‐TADF emitter caused by large energy gap (Δ E ST ) small spin‐orbit coupling (SOC) matrix elements between singlet triplet excited states limits further development EL devices. Currently, innovative molecular design strategies been developed including heavy atom integration, π‐extended MR framework metal perturbation, so on to improve RISC process for high‐performance Here, overview is presented recent progress with fast ( > 10 −5 s −1 ), particular design, properties, device performance light‐emitting diodes (OLEDs), which intends systematize knowledge this thriving highly efficient emitters. Finally, challenges future prospects materials are discussed comprehensively.

Language: Английский

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Deep‐Blue Narrowband Hetero[6]helicenes Showing Circularly Polarized Thermally Activated Delayed Fluorescence Toward High‐Performance OLEDs

Advanced Materials, Journal Year: 2023, Volume and Issue: 36(1)

Published: Nov. 14, 2023

Abstract Helicenes exhibit substantial potential as circularly polarized luminescence (CPL) active molecules. However, their application in organic light‐emitting diodes (CP‐OLEDs) is typically hindered by the challenge of integrating both high color purity and efficient triplet‐harvesting capability, particularly blue spectral region. Herein, a series hetero[6]helicene‐based emitters that strategically engineered through helical extension deep‐blue double‐boron‐based multiple resonance thermally activated delayed fluorescence (MR‐TADF) motif, introduced. Importantly, does not cause apparent structural deformation or perturb frontier molecular orbitals; thus, preserving emission MR‐TADF characteristics parent molecule. This approach also leads to reduced reorganization energy, resulting with narrower linewidth higher photoluminescence quantum yield. Further, motif enhances racemization barrier improved CPL performance dissymmetry factor values up 1.5 × 10 −3 . Exploiting these merits, devices incorporating chiral dopants demonstrate within Broadcast Service Television 2020 color‐gamut range, record external efficiencies (EQEs) 29.3%, have distinctive electroluminescence (CPEL) signals. Overall, authors’ findings underscore promising strategy for designing narrowband chiroptical materials advancing high‐definition displays.

Language: Английский

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A review of fused-ring carbazole derivatives as emitter and/or host materials in organic light emitting diode (OLED) applications

Materials Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 7(19), P. 4304 - 4338

Published: Jan. 1, 2023

This review focuses on fused-ring carbazole derivatives, their molecular design, electronic and photophysical properties, applications as the emitter and/or host material in organic light emitting diodes (OLEDs).

Language: Английский

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Highly efficient multi-resonance thermally activated delayed fluorescence material toward a BT.2020 deep-blue emitter

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: April 2, 2024

Abstract An ultrapure deep-blue multi-resonance-induced thermally activated delayed fluorescence material (DOB2-DABNA-A) is designed and synthesized. Benefiting from a fully resonating extended helical π-conjugated system, this compound has small ΔE ST value of 3.6 meV sufficient spin–orbit coupling to exhibit high-rate constant for reverse intersystem crossing ( k RISC = 1.1 × 10 6 s –1 ). Furthermore, an organic light-emitting diode employing DOB2-DABNA-A as emitter fabricated; it exhibits emission at 452 nm with full width half maximum 24 nm, corresponding Commission Internationale de l’Éclairage (CIE) coordinates (0.145, 0.049). The high reduces the efficiency roll-off, resulting in external quantum (EQE) 21.6% 1000 cd m –2 .

Language: Английский

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Deep-blue organic light-emitting diodes for ultrahigh-definition displays

Nature Photonics, Journal Year: 2024, Volume and Issue: 18(11), P. 1161 - 1169

Published: Aug. 19, 2024

Language: Английский

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B‒N covalent bond-involved π-extension of multiple resonance emitters enables high-performance narrowband electroluminescence

National Science Review, Journal Year: 2024, Volume and Issue: 11(6)

Published: March 23, 2024

ABSTRACT Multi-boron-embedded multiple resonance thermally activated delayed fluorescence (MR-TADF) emitters show promise for achieving both high color-purity emission and exciton utilization efficiency. However, their development is often impeded by a limited synthetic scope excessive molecular weights, which challenge material acquisition organic light-emitting diode (OLED) fabrication vacuum deposition. Herein, we put forward B‒N covalent bond-involved π-extension strategy via post-functionalization of MR frameworks, leading to the generation high-order B/N-based motifs. The structurally electronically extended π-system not only enhances rigidity narrow linewidth but also promotes reverse intersystem crossing mitigate efficiency roll-off. As illustrated examples, ultra-narrowband sky-blue (full-width at half-maximum as small 8 nm in n-hexane) have been developed with multi-dimensional improvement photophysical properties compared precursor emitters, enables narrowband OLEDs external quantum efficiencies (EQEmax) up 42.6%, company alleviated decline brightness, representing best reported single-host OLEDs. success these highlights effectiveness our design advanced MR-TADF confirms extensive potential high-performance optoelectronic devices.

Language: Английский

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Tetraborated Intrinsically Axial Chiral Multi‐resonance Thermally Activated Delayed Fluorescence Materials

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(32)

Published: May 23, 2024

Abstract Chiral multi‐resonance thermally activated delayed fluorescence (CP‐MR‐TADF) materials hold promise for circularly polarized organic light‐emitting diodes (CP‐OLEDs) and 3D displays. Herein, we present two pairs of tetraborated intrinsically axial CP‐MR‐TADF materials, R/S ‐ BDBF‐BOH BDBT‐BOH , with conjugation‐extended bidibenzo[ b,d ]furan ]thiophene as chiral sources, which effectively participate in the distribution frontier molecular orbitals. Due to heavy‐atom effect, sulfur atoms are introduced accelerate reverse intersystem crossing process increase efficiency molecules. manifest ultra‐pure blue emission a maximum at 458/459 nm full width half 27 nm, photoluminescence quantum yields 90 %/91 %, dissymmetry factors (| g PL |) 6.8×10 −4 /8.5×10 respectively. Correspondingly, CP‐OLEDs exhibit good performances an external 30.1 % | EL 1.2×10 −3 .

Language: Английский

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Orienting Group Directed Cascade Borylation for Efficient One‐Shot Synthesis of 1,4‐BN‐Doped Polycyclic Aromatic Hydrocarbons as Narrowband Organic Emitters

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(18)

Published: Feb. 22, 2024

Abstract 1,4‐BN‐doped polycyclic aromatic hydrocarbons (PAHs) have emerged as very promising emitters in organic light‐emitting diodes (OLEDs) due to their narrowband emission spectra that may find application high‐definition displays. While considerable research has focused on investigating the properties of these materials, less attention been placed synthetic methodology. Here we developed an efficient method for PAHs, which enables sustainable production emitting materials. By strategically introducing substituents, such methyl, tert ‐butyl, phenyl, and chloride, at C5 position 1,3‐benzenediamine substrates, achieved remarkable regioselective borylation para‐position substituted moiety. This approach facilitated synthesis a diverse range PAHs with good yields exceptional regioselectivity. The demonstrated excellent scalability large‐scale enabled late‐stage transformation borylated products. Mechanistic investigations provided valuable insights into pivotal roles electron effect steric hindrance achieving highly borylation. Moreover, outstanding device performance synthesized compounds 10 b 6 z , underscores practicality significance method.

Language: Английский

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Efficient Deep‐Blue Multiple‐Resonance Emitters Based on Azepine‐Decorated ν‐DABNA for CIE_y below 0.06

Advanced Materials, Journal Year: 2024, Volume and Issue: 36(30)

Published: May 2, 2024

Abstract Ultrapure deep‐blue emitters are in high demand for organic light‐emitting diodes (OLEDs). Although color coordinates serve as straightforward parameters assessing purity, precise control over the maximum wavelength and full‐width at half‐maximum is necessary to optimize OLED performance, including luminance efficiency luminous efficacy. Multiple‐resonance (MR) promising candidates achieving ideal luminescence properties; consequently, a wide variety of MR frameworks have been developed. However, most these experience displacement from color, which limits their practical applicability. Therefore, molecular design that compatible with modulating energy levels output particularly valuable. Here, it demonstrated azepine donor unit induces an appropriate blue‐shift emission while maintaining efficient characteristics, photoluminescence quantum yield, narrow emission, fast reverse intersystem crossing rate. OLEDs using newly developed based on ν ‐DABNA framework simultaneously exhibit ≈30%, efficacy ≈20 lm W −1 , exceptional purity Commission Internationale de l’Éclairage low (0.14, 0.06), notably operational stability. These results demonstrate unprecedentedly compared those observed previously reported emitters.

Language: Английский

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