Recent advances in the design of afterglow materials: mechanisms, structural regulation strategies and applications

Chemical Society Reviews, Год журнала: 2023, Номер 52(22), С. 8005 - 8058

Опубликована: Янв. 1, 2023

Afterglow materials have attracted widespread attention owing to their distinctive and long-lived optical emission properties which create exciting opportunities in various fields.

Язык: Английский

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Metal‐Perturbed Multiresonance TADF Emitter Enables High‐Efficiency and Ultralow Efficiency Roll‐Off Nonsensitized OLEDs with Pure Green Gamut

Advanced Materials, Год журнала: 2022, Номер 35(6)

Опубликована: Ноя. 22, 2022

Abstract Multiresonance (MR)‐induced thermally activated delayed fluorescence (TADF) emitters based on B‐ and N‐embedded polycyclic aromatics are desirable for ultrahigh‐definition organic light‐emitting diodes (OLEDs) due to their high photoluminescence quantum yield (PLQY) narrow bandwidth. But the reverse intersystem crossing (RISC) rates of MR‐TADF usually small, resulting in severe device efficiency roll‐off at brightness. To solve this issue, a sensitizer emitter has been required. Herein, new is developed through coordination Au with B/N‐embedded ligand. Benefitting from perturbation, RISC rate dramatically accelerated 2.3 × 10 7 s −1 , leading lifetime as short 4.3 µs. Meanwhile, PLQY 95% full width half maximum 39 nm (0.18 eV) essentially unchanged after metal coordination. Therefore, PLQY, lifetime, color purity concurrently realized single TADF emitter. Accordingly, vacuum‐deposited OLEDs exhibit high‐performance electroluminescence external (EQE) 35.8% without sensitization. The EQE maintained 32.3% 000 cd m −2 . Furthermore, solution‐processed OLED also achieves excellent performance 25.7% small roll‐off.

Язык: Английский

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Two-Coordinate Thermally Activated Delayed Fluorescence Coinage Metal Complexes: Molecular Design, Photophysical Characters, and Device Application

Chemical Reviews, Год журнала: 2024, Номер 124(7), С. 4332 - 4392

Опубликована: Март 28, 2024

Since the emergence of first green light emission from a fluorescent thin-film organic emitting diode (OLED) in mid-1980s, global consumer market for OLED displays has flourished over past few decades. This growth can primarily be attributed to development noble metal phosphorescent emitters that facilitated remarkable gains electrical conversion efficiency, broadened color gamut, and vibrant image quality displays. Despite these achievements, limited abundance metals Earth's crust spurred ongoing efforts discover cost-effective electroluminescent materials. One particularly promising avenue is exploration thermally activated delayed fluorescence (TADF), mechanism with potential fully harness excitons OLEDs. Recently, investigations have unveiled TADF series two-coordinate coinage (Cu, Ag, Au) complexes. These organometallic materials exhibit distinctive behavior comparison their counterparts. They offer benefits such as tunable emissive colors, short lifetimes, high luminescent quantum yields, reasonable stability. Impressively, both vacuum-deposited solution-processed OLEDs incorporating achieved outstanding performance. review encompasses various facets on complexes, including molecular design, photophysical characterizations, elucidation structure–property relationships, applications.

Язык: Английский

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Acceleration of reverse intersystem crossing in multi-resonance TADF emitter

Chem, Год журнала: 2024, Номер 10(5), С. 1485 - 1501

Опубликована: Фев. 15, 2024

Язык: Английский

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The Golden Age of Thermally Activated Delayed Fluorescence Materials: Design and Exploitation

Chemical Reviews, Год журнала: 2024, Номер unknown

Опубликована: Дек. 12, 2024

Since the seminal report by Adachi and co-workers in 2012, there has been a veritable explosion of interest design thermally activated delayed fluorescence (TADF) compounds, particularly as emitters for organic light-emitting diodes (OLEDs). With rapid advancements innovation materials design, efficiencies TADF OLEDs each primary color points well white devices now rival those state-of-the-art phosphorescent emitters. Beyond electroluminescent devices, compounds have also found increasing utility applications numerous related fields, from photocatalysis, to sensing, imaging beyond. Following our previous review 2017 (

Язык: Английский

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Energy‐Efficient Stable Hyperfluorescence Organic Light‐Emitting Diodes with Improved Color Purities and Ultrahigh Power Efficiencies Based on Low‐Polar Sensitizing Systems

Advanced Materials, Год журнала: 2023, Номер 35(22)

Опубликована: Март 9, 2023

Multi-resonance (MR) molecules with thermally activated delayed fluorescence (TADF) are emerging as promising candidates for high-definition displays because of their narrow emission spectra. However, the electroluminescence (EL) efficiencies and spectra MR-TADF highly sensitive to hosts sensitizers when applied organic light-emitting diodes (OLEDs), polar environments in devices often lead significantly broadened EL In this study, a proof-of-concept TADF sensitizer (BTDMAC-XT) low polarity, high steric hindrance, concentration-quenching free feature is constructed, which acts good emitter doped non-doped OLEDs external quantum (ηext s) 26.7% 29.3%, respectively. By combining BTDMAC-XT conventional low-polarity hosts, sensitizing systems small carrier injection barrier full exciton utilization constructed molecule BN2. Hyperfluorescence (HF) employing low-polar successfully improve color quality BN2 afford an excellent ηext 34.4%, record-high power efficiency 166.3 lm W-1 long operational lifetime (LT50 = 40309 h) at initial luminance 100 cd m-2 . These results provide instructive guidance design device optimization energy-efficient stable HF-OLEDs high-quality light.

Язык: Английский

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Au(I)‐TADF Emitters for High Efficiency Full‐Color Vacuum‐Deposited OLEDs and TADF‐Sensitized Fluorescent OLEDs with Ultrahigh Brightness and Prolonged Operational Lifetime

Advanced Optical Materials, Год журнала: 2023, Номер 11(23)

Опубликована: Июль 14, 2023

Abstract Herein a class of structurally simple and operationally stable Au(I)‐TADF (TADF = thermally activated delayed fluorescence) materials, based on carbene–metal–amide (CMA) molecular scaffold comprised sterically bulky N ‐heterocyclic carbene ligands with π ‐annulation, are reported. These CMA(Au) emitters stable, adopt coplanar or orthogonal geometry between the amide ligands, show strong blue to deep red TADF emissions (466–666 nm) from equilibrated singlet ligand‐to‐ligand‐charge‐transfer excited states emission quantum yields 0.63–0.99 radiative decay rate constants 0.68–3.2 × 10 6 s −1 in thin film samples at room temperature. The effects increasing ‐extension similarly manifested reduction both singlet–triplet energy gap S 1 transition dipole moment. vacuum‐deposited Au(I) organic light‐emitting diodes (OLEDs) display superior electroluminescence characterized by ultrahigh brightness up 300 000 cd m −2 external efficiencies (EQEs) 26.2% roll‐offs down 2.6% 1000 alongside record‐setting device lifetimes (LT 95 ) 2082 h. Ultrapure‐green TADF‐sensitized fluorescent OLEDs employing emitter as sensitizer multiresonance terminal achieve EQEs 25.3%.

Язык: Английский

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Indolocarbazole Derivatives for Highly Efficient Organic Light‐Emitting Diodes

Advanced Energy Materials, Год журнала: 2024, Номер unknown

Опубликована: Март 12, 2024

Abstract Since the discovery of organic light‐emitting diode (OLED), scientists worldwide have dedicated extensive efforts to enhance efficiency and reliability devices, striving for superior performance. Various molecular structures undergone structural modifications assess their suitability in achieving desired outcomes. This review focuses on indolo[3,2,1‐ jk ]carbazole (ICz), a building block that has garnered considerable attention within OLED community. The rigid fused ICz core induces multiresonance effect through an alternating distribution frontier orbitals. Notably, ICz‐based thermally activated delayed fluorescence emitters exhibit full width at half maximum below 20 nm, ensuring high color purity, boast external quantum above 30%, comparable state‐of‐the‐art narrow‐emitting boron–nitrogen‐type materials. Furthermore, is host metal complexes, enhancing stability, efficiency, purity. Consequently, promising as central component emitters, improving device aims succinctly summarize studies materials field, offering insights into future perspectives regarding developing applying ICz‐derived compounds.

Язык: Английский

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Highly Efficient Copper(I) Emitters Supported by Secondary Metal‐Ligand Interactions

Advanced Optical Materials, Год журнала: 2024, Номер 12(17)

Опубликована: Март 14, 2024

Abstract The most prominent way of tuning optoelectronic properties copper(I) emitters is primary‐sphere ligand engineering, but little attention placed on noncovalent interactions. Here, an effective strategy demonstrated to introduce secondary metal‐ligand interactions into two‐coordinate Cu(I) with the goals optimizing conformations and improving optical properties. As a proof concept, panel complexes developed via chalcogen‐heterocyclic engineering 1,2‐positions carbazole ligand. S‐embedded have distinct originating from S···Cu orbital contacts, verified by single‐crystal structure theoretical simulation. Thanks flattened stabilized interactions, optimized afford high emission quantum yields up 93% short radiative lifetimes down 0.8 µs. Cu‐12BT Cu‐12BF support resultant organic light‐emitting diodes (OLEDs) delivering outstanding maximum external efficiencies (EQEs) 24.3% 28.6%, respectively, among best performance for emitters. optimal devices based also achieve 18.7% EQE at practical luminance 100 nits. This work unlocks large potential in developing excellent cost‐effective high‐efficiency OLEDs.

Язык: Английский

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A Configurationally Confined Thermally Activated Delayed Fluorescent Two‐Coordinate Cu^I Complex for Efficient Blue Electroluminescence

Angewandte Chemie International Edition, Год журнала: 2022, Номер 62(7)

Опубликована: Дек. 21, 2022

Abstract Thermally activated delayed fluorescence (TADF) from linear two‐coordinate coinage metal complexes is sensitive to the geometric arrangement of ligands. Herein we realize tuning configuration coplanar orthogonal gradually by variation substituents. In a complex with confined twist configuration, its blue emission peaking at 458 nm presents high Φ PL 0.74 and short τ TADF 1.9 μs, which indicates fast enough k r,TADF 3.9×10 5 s −1 depressed nr 1.4×10 . Such outstanding luminescent properties are attributed proper overlap HOMO LUMO on Cu I d orbitals that guarantees not only small Δ E ST but also sufficient transition oscillator strength for Vacuum‐deposited OLEDs either doped or host‐free emissive layer present external quantum efficiencies over 20 % 10 %, respectively, demonstrating practicality configurationally strategy efficient emitters.

Язык: Английский

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