Enabling Ultra‐Narrow‐Band Deep‐Blue Light‐Emitting Diode Via Trapping Injected Holes by Carbon Dots

Advanced Functional Materials, Год журнала: 2024, Номер unknown

Опубликована: Июль 28, 2024

Abstract Narrow‐band deep‐blue light‐emitting diodes (LEDs) (CIE y coordinate<0.08, full width at half maximum (FWHM)<20 nm) are important for the next generation of LED‐based displays. It remains a significant challenge design narrow‐band emitters. Herein, new strategy is proposed constructing LEDs that not dependent on emitter, but only need to dope n‐type carbon dots (n‐CDs) in active emission layer (EML) wide‐band blue LEDs. The n‐CDs‐LEDs show an ultra‐narrow 430 nm with color coordinates (0.15, 0.04) and FWHM 19 nm. Wherein EML constructed by doping n‐CDs Poly(9,9‐dioctylfluorene‐co‐N‐(4‐butylphenyl) diphenylamine) (TFB), which neither changes band structure TFB nor produces energy levels. Transient photovoltage (TPV) various photoelectrochemical characterizations jointly reveal can trap holes realize carrier injection into single level achieve light emission. This work provides brand‐new simple way

Язык: Английский

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Dual‐Core Engineering for Efficient Deep‐Blue Multiple Resonance Thermally Activated Delayed Fluorescent Materials

Advanced Functional Materials, Год журнала: 2024, Номер unknown

Опубликована: Сен. 9, 2024

Abstract Developing narrowband blue multiple resonance (MR) organic emitters with Commission Internationale de L'Eclairage (CIE) y coordinates <0.1 is essential for advanced display technologies. This study proposes a deep‐blue thermally activated delayed fluorescence (TADF) emitter, named 2BNO, which integrates two independent MR cores. Unlike many TADF materials single‐bonded dual emitting cores, 2BNO utilizes steric hindrance‐assisted fluorene bridge to achieve an orthorhombic molecular structure. The dual‐core MR‐TADF emitter shows enhanced light absorption and high photoluminescence quantum yield. Notably, the emission of not significantly redshifted compared single‐core compounds maintains narrow full width at half‐maximum (FWHM) 24 nm CIE (0.147, 0.041) in 2Me‐THF solution, nearing BT.2020 standard. Organic light‐emitting diodes (OLEDs) incorporating as exhibit 460 FWHM 29 (0.14, 0.09). core design improves device efficiency, achieving external efficiency (EQE) 19.8%. strategy this work demonstrated be effective promoting while preserving color purity.

Язык: Английский

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Efficient non-doped blue electrofluorescence with electric field dependence of electron mobility

Chemical Engineering Journal, Год журнала: 2024, Номер unknown, С. 156905 - 156905

Опубликована: Окт. 1, 2024

Язык: Английский

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Efficient and Multifunctional Electroluminescent Ultra Deep‐Blue Material with Hybrid Localization and Charge Transfer

Advanced Functional Materials, Год журнала: 2025, Номер unknown

Опубликована: Фев. 9, 2025

Abstract Hybrid local and charge transfer (HLCT) emitters have received much attention because they can utilize triplet exciton via hot channels. However, exploiting novel multifunctional deep‐blue HLCT materials capable of high color purity remains a great challenge. Herein, two with properties, PdCz‐2CN mPdCz‐2CN, aresynthesized. The non‐doped OLED based on or mPdCz‐2CN emitter EQE max Commission Internationale de l'Eclairage (CIE) coordinates Y values 5.42%@0.062 [email protected], respectively. More importantly, the doped‐OLEDs achieve ultra emission CIEy 5.10%@0.037 1.96%@0.050, respectively, which is close to BT.2020 standard. In addition, not only obtain ultra‐deep blue OLED, but also realize exciplex‐OLED as electron acceptor for realizing luminescence. As result, exciplex PdCz‐2CN: 15 wt.%TAPC luminescent layer achieves 15.44% forming green hole transport TAPC. Moreover, exciplex‐based host, red phosphor Ir(MDQ) 2 (acac) guest reaches emission, isup 20.14%. This study first using picolinonitrile an acceptor, having significant potential efficient applications.

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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High-Efficiency Deep-Blue Solution-Processed OLED Devices Enabled by New Dopant Materials

Materials, Год журнала: 2025, Номер 18(10), С. 2213 - 2213

Опубликована: Май 10, 2025

Two blue fluorescent dopants were designed and successfully synthesized, 5-(2,12-di-tert-butyl-5,9-dioxa-13b-boranaphtho [3,2,1-de]anthracen-7-yl)-5H-benzo[b]carbazole (TDBA-Bz) 9-(2,12-di-tert-butyl-5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracen-7-yl)-9H-carbazole (TDBA-Cz). Both in solution the film state, two emitters demonstrated deep-blue luminescence characteristics. In solution-processed organic light-emitting diodes (OLEDs), TDBA-Bz TDBA-Cz used as dopant materials showed electroluminescence peaks at 436 nm 413 nm, respectively. The corresponding CIE color coordinates determined to be (0.181, 0.114) for (0.167, 0.086) TDBA-Cz. device using a exhibited current efficiency (CE) of 7.25 cd/A an external quantum (EQE) 6.45%, demonstrating higher efficiencies compared with TDBA-Bz. particular, luminance 2000 cd/m2, maintained EQE 4.81%, only slight decrease from its maximum EQE.

Язык: Английский

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Deep blue OLEDs satisfying BT. 2020 standard enabled by a simple-structured multiple resonance emitter with CIEy coordinate of 0.02

Chemical Engineering Journal, Год журнала: 2025, Номер unknown, С. 164225 - 164225

Опубликована: Май 1, 2025

Язык: Английский

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B─N Covalent Bonds and Twin‐Spiro Fused Design Strategy for the Construction of Narrowband Multiple Resonance Emitters

Advanced Functional Materials, Год журнала: 2025, Номер unknown

Опубликована: Май 29, 2025

Abstract Developing the modified skeleton of multi‐resonance thermally activated delayed fluorescence (MR‐TADF) emitters can feasibly regulate their optoelectronic properties. However, research on MR‐TADF materials incorporating B─N covalent bonds remains relatively limited. Herein, a strategy is first proposed utilizing twin‐spiro conformation, dispirofluorene acridine (DSAF), via amine‐directed double borylation for framework fusion to construct emitters, DSAF‐TBDPA and DSAF‐TBCz. are employed enhance structural rigidity molecular framework. Furthermore, introduction structure imparts steric hindrance, thereby weakening π – interactions mitigating exciton quenching. As result, DSAF‐TBCz exhibit narrowband emission with full width at half maximum 20 19 nm. The doped organic light‐emitting diodes (OLEDs) based external quantum efficiencies (EQE max ) 27.2% 30.8%, respectively. These results underscore that design tactics not only expand diversity MR frameworks but also deliver critical insights high‐performance OLED emitters.

Язык: Английский

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Theoretical Investigation and Molecular Design: A Series of Tripod-Type Cu(I) Blue Light Thermally Activated Delayed Fluorescence Materials

Inorganic Chemistry, Год журнала: 2024, Номер 63(38), С. 17435 - 17448

Опубликована: Сен. 4, 2024

The photophysical properties and luminescent mechanism of a series tripod-type Cu(I) complexes in solution solids were comprehensively investigated through theoretical simulations. From microscopic perspective, the experimental phenomenon is explained: (1) intrinsic reason for quenching complex

Язык: Английский

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Asymmetric structural strategy enables efficient MR-TADF emitters with low efficiency roll-off and doping-concentration insensitivity

Chemical Engineering Journal, Год журнала: 2024, Номер 499, С. 155864 - 155864

Опубликована: Сен. 16, 2024

Язык: Английский

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