Recent Progress of Thermally Activated Delayed Fluorescent Materials with Narrowband Red, Green, and Blue (RGB) Emission

ACS Materials Letters, Journal Year: 2024, Volume and Issue: 6(5), P. 1746 - 1768

Published: April 2, 2024

Narrowband thermally activated delayed fluorescence (TADF) materials have received widespread attention due to their promising applications in organic light-emitting diodes with high-definition displays. Great efforts been done achieve full-color narrowband emissions donor–acceptor (D–A) and multiple-resonance (MR) TADF materials. In comparison the D–A materials, MR-based basically showed smaller full width at half-maximum (fwhm) of spectra owing inherent structural vibration inhibition electronic transition characteristics. Herein, review summarizes current research progress on both MR blue, green red emission regions fwhm less than 70 nm concentrating molecular design strategies, photophysical properties corresponding device performance, proposes some possible future topic. This aims give physical insight structure–property relationship such offer guidance for further developing provide a structured database platform high-throughput or machine learning research.

Language: Английский

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Peripheral Selenium Modification of Multi‐Resonance Thermally Activated Delayed Fluorescence Molecules for High‐Performance Blue Organic Light‐Emitting Diodes

Advanced Optical Materials, Journal Year: 2024, Volume and Issue: 12(11)

Published: Feb. 28, 2024

Abstract Multi‐resonance thermally activated delayed fluorescence (MR‐TADF) molecules have attracted much attention in the academia owing to their unique photoelectrical properties. However, MR‐TADF emitters usually show slow reverse intersystem crossing (RISC) rate, resulting high efficiency roll‐off of organic light‐emitting diodes (OLEDs) and seriously limiting further development. Here, a peripheral selenium (Se) modification is presented for promote RISC process while keeping narrowband emission high‐performance blue OLEDs. Compared parent (NBN t BuNBN), SeNBN Se BuNBN exhibited narrower full‐width at half maximum (FWHM) value 23 nm more obvious properties with up 86%, shorter lifetime 2.4 µs as well faster rate 3.34×10 5 s −1 . Therefore, OLEDs based on these two modified are achieved external quantum (EQE) 25.5% extremely suppressed roll‐offs 3.9% 100 cd m −2 24.4% 1000 This work demonstrated that introduction atom can achieve semiconductors both fast constant optoelectronic devices.

Language: Английский

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Multiple‐resonance thermally activated delayed emitters through multiple peripheral modulation to enable efficient blue OLEDs at high doping levels

Aggregate, Journal Year: 2024, Volume and Issue: 5(5)

Published: May 13, 2024

Abstract Organic light‐emitting diodes (OLEDs) based on multiple resonance‐thermally activated delayed fluorescence (MR‐TADF) have the advantages of high exciton utilization and excellent color purity. However, large conjugated planarity general MR‐TADF emitters makes them easily aggregate in form π–π stacking, resulting aggregation‐caused quenching (ACQ) formation excimers, which reduce efficiency To address these issues, shielding units can be incorporated to prevent interchromophore interactions, whereas majority reported molecules are limited blue‐green light emissions. This work proposes a strategy incorporating steric hindrance groups at different sites B/N core suppress interactions between chromophore, contributing blue with photo‐luminance quantum yields (PLQYs ≥ 95%) narrow full width half maximum (FWHM), importantly, great suppression ACQ effect. Therefore, OLEDs achieve external efficiencies up 34.3% purity FWHM about 27 nm CIE around (0.12, 0.15), even doping concentration 20 wt%.

Language: Английский

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Efficient Ultra‐Narrowband OLEDs Based on Carbazole‐Fused Dual‐Boron Embedded Multi‐Resonance Thermally Activated Delayed Fluorescence Materials

Advanced Optical Materials, Journal Year: 2024, Volume and Issue: 12(15)

Published: Jan. 2, 2024

Abstract The development of efficient multi‐resonance thermally activated delayed fluorescence (MR‐TADF) materials with ultra‐narrowband emission presents an ongoing challenge. In this work, a carbazole‐fused dual‐boron embedded MR‐TADF framework is proposed, achieving three emitters, CFDBO, CFDBA, and CFDBCz, via one‐shot borylation very high yields over 70%. emitters display blue peaks ranging from 452 to 479 nm small full width at half maximum (FWHM) values only 16–18 in dilute toluene solutions. Furthermore, the organic light‐emitting diode (OLED) incorporating CFDBO exhibits pure‐blue peak 460 Commission International de l'Eclairage coordinates (0.14, 0.12). Meanwhile, OLEDs CFDBA/CFDBCz demonstrate remarkable performances external quantum efficiencies 30.9%/32.4% exceptionally slender FWHM 21/22 nm, representing outstanding among reported materials.

Language: Английский

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Phosphine oxide balanced charge transfer hybridization in multi-resonance emitters: towards ∼40% external quantum efficiency and preserved color purity

Chemical Engineering Journal, Journal Year: 2024, Volume and Issue: 489, P. 151517 - 151517

Published: April 22, 2024

Language: Английский

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Quantitative prediction of rate constants and its application to organic emitters

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

Published: June 3, 2024

Many phenomena in nature consist of multiple elementary processes. If we can predict all the rate constants respective processes quantitatively, comprehensively and understand various phenomena. Here, report that it is possible to quantitatively related quantum yields without conducting experiments, using multiple-resonance thermally activated delayed fluorescence (MR-TADF) as an example. MR-TADFs are excellent emitters because its narrow emission, high luminescence efficiency, chemical stability, but they have one drawback: slow reverse intersystem crossing (RISC), leading efficiency roll-off reduced device lifetime. show a calculation method for obtaining yields. This study reveals strategy improve RISC compromising other important factors: radiative decay constants, photoluminescence yields, emission linewidths. Our be applied wide range research fields, providing comprehensive understanding mechanism including time evolution excitons.

Language: Английский

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Recent Advances in Narrow Emission Bandwidth Materials for Application in Organic Light‐Emitting Diodes

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

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Quadrupling the PLQY of Tetraphenylethylene by Covalently Linking it with Isosteric Tetraarylaminoborane: A Potential Candidate for Multicolor Live Cell Imaging

Inorganic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: March 13, 2025

Applications of organic luminophores depend on their photoluminescence quantum yield (PLQY). Several strategies have been developed to improve the PLQY solids, and one such method is aggregation-induced emission (AIE). Herein, we disclose a comprehensive study two molecularly engineered covalently linked isosteric AIEgens, BNTPE-1 BNTPE-2. The independent isosteres tetraarylaminoborane (BN) tetraphenylethylene (TPE) showed poor PLQY; however, BNTPE-2 systems 4 times higher than (∼78 ∼92% for solids aggregates, respectively). Detailed optical, structural, computational studies revealed that BN TPE moieties adopt more coplanarity stronger donor (–NPh2)–acceptor (BMes2) interactions in do simple units. Despite having sterically demanding BMes2 units, these compounds are nonemissive solution state due presence flexible However, they strongly emissive condensed states, as aggregates solid state. excited structure analysis unit undergoes severe conformational distortion after photoexcitation, which activates nonradiative decay channels consequently quenches luminescence dispersed bioimaging potential was also explored. These high biocompatibility stained HeLa cells brighter molecules.

Language: Английский

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Marching Toward Long‐Wavelength Narrowband Emissive Multi‐Resonance Delayed Fluorescence Emitters for Organic Light Emitting Diodes

Advanced Optical Materials, Journal Year: 2023, Volume and Issue: 11(22)

Published: Oct. 4, 2023

Abstract Over the past decade, thermally activated delayed fluorescence (TADF) emitters have garnered tremendous impetus because of their ability to harvest 100% excitons for light emission in organic emitting diodes (OLEDs). However, despite superior external quantum efficiencies (> 35%), broad spectra with associated full‐width‐at‐half maximum (FWHM > 70 nm) present a limiting factor that must be solved. Recently, multiple‐resonance TADF (MR‐TADF) materials based on heteroatom doped polyaromatic hydrocarbons gained astonishing attention owing remarkable narrowband < 30 nm). majority reported MR‐TADF falls blue/green region, which inevitably jeopardizes application full‐color OLEDs. Therefore, there is an urgent need develop new molecular designs expanding color‐gamut emitters, i.e., λ em 550 nm without compromising emission. To best current knowledge, no detailed reviews focusing different design strategies producing long‐wavelength been date. this end, review highlighting recent advances constructing presented, and photophysics OLED performance discussed. Finally, status future prospects are

Language: Английский

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High‐Efficiency Ultraviolet Electroluminescence from Multi‐Resonance Phosphine Oxide Polycyclic Aromatics

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 63(5)

Published: Dec. 7, 2023

Abstract Efficient ultraviolet (UV) electroluminescent materials remain a great challenge, since short peak wavelength <400 nm and narrow full width at half maximum (FWHM) <50 are simultaneously required. In this sense, multi‐resonance (MR) thermally activated delayed fluorescence (TADF) emitters featuring narrow‐band emissions hold the promise for UV applications. Herein, novel MR‐TADF skeleton carbazole‐phosphine oxide (P=O) fused aromatics is developed to construct first two MR named CzP2PO tBCzP2PO . addition synergistic resonance effects of P=O N atom, sp 3 ‐hybrid P atom renders curved polycyclic planes , giving rise their narrowband with wavelengths <390 FWHM<35 nm. Besides configuration quasi‐planarization radiation enhancement quenching suppression, moiety further enhances singlet‐triplet coupling facilitate reverse intersystem crossing, resulting in state‐of‐the‐art photoluminescence quantum yield 62 % doped films. As consequence, endowed its organic light‐emitting diodes 382 FWHM 32 nm, especially record‐high external efficiency (EQE) 15.1 among all kinds devices. Our results demonstrate potential based practical applications including optoelectronics, biology medicine science.

Language: Английский

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