Achieving Narrowband and Stable Pure Blue Organic Light‐Emitting Diodes by Employing Molecular Vibration Limited Strategies in the Extended π‐Conjugated Indolocarbazole Skeleton

Advanced Science, Год журнала: 2025, Номер unknown

Опубликована: Янв. 13, 2025

Abstract B‐ and N‐heterocyclic fluorophores have reveal promising efficiency in blue organic light‐emitting diodes (OLEDs) with small full‐width‐at‐half‐maximum (FWHM). However, their structural determinants for spectral broadening operating stability are still needed to be investigated further. Herein, a novel multi‐N‐heterocycles Diindolo[3,2,1jk:3′,2′,1′jk]dicarbazole[1,2‐b:4,5‐b] (DIDCz) is proposed manipulate the emission color toward pure region by extending π‐conjugation of N‐π‐N bridge. By utilizing computed technique, interrelationships between indolocarbazole (ICz)‐cyclization sites defined. Molecular backbone modifications involving optimized 2,3,6,7‐ICz cyclization steric hindrance substituents conducive restricting swing peripheral bonds stretching resonances polycyclic aromatic hydrocarbon (PAH) frameworks, thereby contributing reduction shoulder peaks. Consequently, DIDCz‐based chromophore exhibited narrowband FWHM only 15 nm, achieving highly efficient (external quantum efficiencies 8.87% triplet–triplet fusion fluorescence 22.3% sensitized fluorescence) long‐term (95% initial luminance 1000 cd m −2 , T95 = 1545 h) electroluminescence performances, showing one most stable OLEDs among reported PAH chromophores. The current achievements offer new perspective manage precisely based on molecular vibration limiting technique.

Язык: Английский

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High-Efficiency, Long-Lived, Multicolor Tunable Pure Organic Materials for Dual Fluorescent-Phosphorescent Emission at Room Temperature

ACS Applied Optical Materials, Год журнала: 2025, Номер unknown

Опубликована: Янв. 10, 2025

Currently, numerous afterglow materials often suffer from low phosphorescence quantum yields (ΦPh) and are confined to a singular luminescent color. In this study, we devised an approach by incorporating four distinct carbazole derivative guest molecules, featuring varying degrees of halogen substitution naphthalene group sites, into β-estradiol host molecules through high-temperature melt doping create exceptional organic composites. Remarkably, all exhibit characteristics, including prolonged lifetimes ultrahigh yields, with the pinnacle lifetime soaring 904.76 ms peak yield achieving remarkable 40.0%. Notably, even without heavy atom incorporation, phosphors managed attain ΦPh 18.0%, underscoring their unique properties. Furthermore, our experiments unveiled intriguing phenomenon: rather than single fluorescence or emission, these dual-emission encompassing both phosphorescence. The versatility in luminescence color manipulation was further demonstrated adjusting temperature excitation wavelength, offering unparalleled flexibility. Moreover, hues could be finely tuned number atoms, adding another layer tunability. Theoretical calculations provided valuable insights, showing that changes bromine substitutions positions significantly affect molecule's spin–orbit coupling constants nature its excited states. This understanding not only highlights molecular mechanisms behind observed properties but also provides roadmap for future design optimization such advanced materials.

Язык: Английский

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Intramolecular-Locking Modification Enables Efficient Asymmetric Donor-Acceptor-Donor’ Type Ultraviolet Emitters for High-Performance OLEDs with Reduced Efficiency Roll-Off and High Color Purity

Chemical Science, Год журнала: 2025, Номер unknown

Опубликована: Янв. 1, 2025

Developing high-performance ultraviolet organic light-emitting diodes with low efficiency roll-off and high color purity remains challenging due to their inherent wide-bandgap characteristics. In this work, we present an intramolecular noncovalent bond locking strategy modulate donor-acceptor-donor' (D-A-D') type fluorophores (mPImCZ2F, mPIoCZ2F mPImCP2F) a hot-exciton mechanism. Notably, these asymmetric emitters exhibit significantly enhanced bipolar transport capacity fluorescence compared counterparts. Among them, exhibits more remarkable effect multiple C-H⋯F interactions ortho-substitution-induced steric hindrance, which endows it higher radiation rate, narrower emission spectrum, balanced charge transport. Consequently, the mPIoCZ2F-based non-doped device achieves electroluminescence (EL) peak at 393 nm maximum external quantum (EQE) of 6.62%. Moreover, in doped device, emits stable light EL 391 full width half (FWHM) 40 nm, corresponding coordinates (0.167, 0.025). It also exceptionally EQE 8.71% minimal (7.95% 1000 cd m-2), ranking among best efficiencies reported for UV-OLEDs brightness levels.

Язык: Английский

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Switching between TADF and HLCT emissions by connecting different donors based on theoretical calculations

New Journal of Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Янв. 1, 2025

Significantly, the benzofuran-modified polycyclic molecules by regulating donor ability, which achieved a switch between thermally activated delayed fluorescence (TADF) and hybrid local charge transfer (HLCT) emissions.

Язык: Английский

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Simultaneous Emission Spectral Narrowing and Spin‐Flip Acceleration in Multi‐Resonance Organoboron Emitters via Sequential Indolo‐Fusion π‐Extension

Advanced Optical Materials, Год журнала: 2025, Номер unknown

Опубликована: Март 17, 2025

Abstract Advanced cutting‐edge organic light‐emitting diode (OLED) technologies require narrowband electroluminescence (EL) with high quantum efficiency to growing performance demand. Here, sequential indolo‐fusion π‐extension as a rational design strategy further narrow the emission bandwidth of multi‐resonance thermally activated delayed fluorescence (MR‐TADF) is introduced. By fusing one or two additional indole moieties periphery Cz‐B, typical MR‐TADF motif, gradual spectra narrowing, and accelerated triplet–singlet exciton spin conversion are concurrently achieved. Suppressing vibronic couplings induced by high‐frequency vibrational modes vital for achieving extreme spectral narrowing. OLEDs based on doubly indolo‐fused emitter, IDCz‐B‐II, exhibited ultra‐narrowband sky‐blue EL full width at half maximum 21 nm (0.11 eV), external 25.9%, reduced roll‐off, significantly outperforming Cz‐B‐based device. The present provides simple yet promising approach developing isomeric materials different positions orientations.

Язык: Английский

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Application of Organic Light-Emitting Diodes and Photodiodes in Optical Control and Detection of Neuronal Activity

Photonics, Год журнала: 2025, Номер 12(3), С. 281 - 281

Опубликована: Март 18, 2025

Optical techniques to study neuronal activity have greatly advanced the field of neuroscience over recent decades. Multichannel silicon-based recording probes combined with optical fibers allow for simultaneous and manipulation that underpins cognitive processes behavior. The development neural incorporating organic light-emitting diodes (OLEDs) photodiode-based photodetectors (OPDs) offer additional advantages biocompatibility, ultra-small footprint, multifunctionality, low cost. These developments are ushering in a new generation devices ideal interrogation vitro vivo. In this review, we discuss progress OLED- OPD-based probes, their applications control function, current challenges prospects future.

Язык: Английский

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Recent Progress in Molecular Design of Boron/Nitrogen‐Based Multi‐Resonance Materials for Narrowband Organic Light‐Emitting Diodes

Advanced Optical Materials, Год журнала: 2025, Номер unknown

Опубликована: Апрель 11, 2025

Abstract Luminescent boron‐nitrogen (BN)‐type multi‐resonance (MR) materials have been first reported by Hatakeyama and co‐workers in 2016. BN‐type MR attracted a lot of attention, because their unique photophysical properties, including narrowband emissions, high photoluminescent quantum yields, thermally activated delayed fluorescent (TADF) properties. MR‐TADF are considered as the next‐generation luminescent for efficient, stable, narrow‐emission organic light‐emitting diodes (OLEDs). Herein, comprehensive review recent progress is provided highlighting structures, device performances. Moreover, future perspective development will be discussed.

Язык: Английский

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Advancing Fully Solution‐Processed Blue OLEDs with Low‐Temperature Cross‐Linkable Single‐Component Polymeric Emitters

Advanced Optical Materials, Год журнала: 2025, Номер unknown

Опубликована: Май 6, 2025

Abstract The development of fully solution‐processed organic light‐emitting diodes (fs‐OLEDs) remains a significant challenge, primarily due to the lack low‐temperature cross‐linkable materials for emissive layer (EML). In this study, novel material design strategy is reported blue fs‐OLEDs, where single framework can be adapted as cross‐linked hole transport ( X‐HTL ), polymer hosts, or single‐component EML P27 , X‐P33 with minor structural modifications. Particularly, ) demonstrates remarkably low cross‐linking temperature T CL 135 °C, showing no reduction in photoluminescence quantum yield EML. A fs‐OLED comprising achieves comparable efficiency partial device, demonstrating its promised application. rationally designed pyrene‐based emitting small molecule, 3,8‐DI‐DAP‐C7 additionally introduced. Employing dopant, current ≈4.7 cd −1 and external 3.2% achieved.

Язык: Английский

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Comprehensive Review on the Structural Diversity and Versatility of Multi-Resonance Fluorescence Emitters: Advance, Challenges, and Prospects toward OLEDs

Chemical Reviews, Год журнала: 2025, Номер unknown

Опубликована: Май 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.

Язык: Английский

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Excited-State Engineering toward Accelerated Reverse Intersystem Crossing in Diindolocarbazole-Embedded Multiple-Resonance Emitters for High-Performance Blue OLEDs

ACS Applied Materials & Interfaces, Год журнала: 2025, Номер unknown

Опубликована: Май 16, 2025

Simultaneously achieving a narrow emission band, high efficiency, and excellent color purity remains formidable challenge in the development of blue organic light-emitting diodes (OLEDs). Diindolocarbazole-embedded multiple-resonance emitters show great potential owing to their extremely but practical applications are severely limited by slow reverse intersystem crossing rate (kRISC) with order magnitude value 102. Herein, we present an effective strategy accelerate RISC process acceptor decoration regulate excited state. Through modulating electron-withdrawing ability from TFB TPT, long-range charge transfer state is successfully induced, which leads decreased ΔEST increased spin-orbital coupling (SOC) matrix elements, contributing dramatically accelerated kRISC up 1.11 × 104 s-1 for pICz-TPT. Moreover, narrowband basically retained proof-of-concept pICz-TPT peak at 449 nm, full width half-maximum 44 CIE coordinates (0.15, 0.10). Impressively, nonsensitized OLEDs based on emitter exhibit highest maximum external quantum efficiency (EQEmax) 14.4% among all reported basis pICz derivatives (which typically remained below 5%), further boost EQEmax 24.2% realized hyperfluorescent OLEDs. This work provides powerful design tool toward highly efficient good purity.

Язык: Английский

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