Thermally Enhanced and Long Lifetime Red TADF Carbon Dots via Multi‐Confinement and Phosphorescence Assisted Energy Transfer

Advanced Materials, Journal Year: 2023, Volume and Issue: 35(20)

Published: March 9, 2023

Thermally activated delayed fluorescence (TADF) materials, which can harvest both singlet and triplet excitons for high-efficiency emission, have attracted widespread concern their enormous applications. Nevertheless, luminescence thermal quenching severely limits the efficiency operating stability in TADF materials devices at high temperature. Herein, a surface engineering strategy is adopted to obtain unique carbon dots (CDs)-based thermally enhanced with ≈250% enhancement from 273 343 K via incorporating seed CDs into ionic crystal network. The rigid network simultaneously boost reverse intersystem crossing process enhancing spin-orbit coupling between states suppressing non-radiative transition rate, contributing character. Benefiting efficient energy transfer of phosphorescence center CDs, emission ≈600 nm displays long lifetime up 109.6 ms, outperforming other red organic materials. Thanks variable decay rates centers, time temperature-dependent color has been first realized CDs-based time-/temperature-dependent one material system offer new opportunities information protection processing.

Language: Английский

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Room Temperature Phosphorescence Carbon Dots: Preparations, Regulations, and Applications

Small, Journal Year: 2023, Volume and Issue: 19(33)

Published: April 22, 2023

Abstract Room temperature phosphorescence (RTP) materials have drawn considerable attention by virtue of their outstanding features. Compared with organometallic complexes and pure organic compounds, carbon dots (CDs) emerged as a new type RTP materials, which show great advantages, such moderate reaction condition, low toxicity, cost, tunable optical properties. In this review, the important progress made in CDs is summarized, an emphasis on latest developments. The synthetic strategies will be comprehensively followed detailed introduction performance regulation potential applications anti‐counterfeiting, information encryption, sensing, light‐emitting diodes, biomedicine. Finally, remaining major challenges for are discussed opportunities future proposed.

Language: Английский

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Recent Advances of Carbon Dots with Afterglow Emission

Small, Journal Year: 2023, Volume and Issue: 19(31)

Published: Feb. 21, 2023

Abstract Carbon dots (CDs) have gradually become a new generation of nano‐luminescent materials, which received extensive attention due to excellent optical properties, wide source raw low toxicity, and good biocompatibility. In recent years, there are many reports on the luminescent phenomenon CDs, great progress has been achieved. However,there rarely systematic summaries CDs with persistent luminescence. Here, summary including luminous mechanism, synthetic strategies, property regulation, potential applications, is given. First, brief introduction given development materials. Then, mechanism afterglow from room temperature phosphorescence (RTP), delayed fluorescence (DF), long luminescence (LPL) discussed. Next, constructed methods materials summarized two aspects, matrix‐free self‐protected matrix‐protected CDs. Moreover, regulation properties color, lifetime, efficiency presented. Afterwards, applications such as anti‐counterfeiting, information encryption, sensing, bio‐imaging, multicolor display, LED devices, etc., reviewed. Finally, an outlook proposed.

Language: Английский

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Intense Circularly Polarized Fluorescence and Room-Temperature Phosphorescence in Carbon Dots/Chiral Helical Polymer Composite Films

ACS Nano, Journal Year: 2023, Volume and Issue: 17(7), P. 6912 - 6921

Published: March 31, 2023

Chiral carbon dots (C-dots) with a circularly polarized fluorescence (CPF) property have attracted tremendous attention due to their significant applications in chiral optoelectronics and theranostics. However, constructing room-temperature phosphorescent (CPRTP) C-dots remains great challenge. Herein, strategy is established achieve efficient CPF CPRTP emissions C-dots/chiral helical polymer bilayer composite film. Taking advantage of the filter effect polymer, intense large dissymmetric factors up 1.4 × 10-1 1.2 10-2 are respectively obtained, even though there only simple interface contact between layer layer. More importantly, white-color emission multiple information display encryption further realized based on prepared luminescent films.

Language: Английский

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Colorful Triplet Excitons in Carbon Nanodots for Time Delay Lighting

Advanced Materials, Journal Year: 2023, Volume and Issue: 35(21)

Published: Feb. 25, 2023

Time delay lighting offers an added period of buffer illumination for human eyes upon switching off the light. Long-lifetime emission from triplet excitons has outstanding potential, but forbidden transition property due to Pauli exclusion principle makes them dark, and it stays challenging develop full-color bright excitons. Herein, ultraviolet (UV) near infrared (NIR) in carbon nanodots (CNDs) is achieved by confining multicolor CNDs emitters NaCNO crystal. crystal can isolate CNDs, quenching caused excited state electrons aggregation induced energy transfer suppressed, confinement furthermore promote phosphorescence inhibiting dissipation non-radiative transition. The radiative recombination covers spectral region 300 nm 800 (NIR), corresponding lifetimes reach 15.8, 818.0, 239.7, 168.4, 426.4, 127.6 ms. Furthermore, eco-friendly luminescent lampshades are designed based on phosphorescent time light-emitting diodes thus demonstrated. findings will motivate new opportunities development UV NIR applications.

Language: Английский

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Polymer–Structure‐Induced Room‐Temperature Phosphorescence of Carbon Dot Materials

Small Structures, Journal Year: 2023, Volume and Issue: 4(5)

Published: Feb. 2, 2023

As emerging carbon‐based nanomaterials, carbon dots (CDs) are widely studied with regard to their luminescent properties. CDs obtained by the bottom‐up method exhibit polymeric characteristics after crosslinking, polymerization, and incomplete carbonization processes, herein referred as carbonized polymer (CPDs). In recent years, large progress has been achieved on room‐temperature phosphorescence (RTP) properties of CPDs. The developments synthesis strategies for RTP CPD materials reviewed. However, less attention devoted influence structures materials. Polymer a common feature extensive key factors facilitating Herein, effects emission self‐protective matrix‐assisted discussed. It is considered that can effectively immobilize subluminophores protect triplet excited states facilitate crosslink‐enhanced (CEE) effect proposed further explain materials, which provide an effective strategy Benefiting from CEE effect, efficient be applications then briefly summarized.

Language: Английский

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Room-temperature phosphorescent materials derived from natural resources

Nature Reviews Chemistry, Journal Year: 2023, Volume and Issue: 7(11), P. 800 - 812

Published: Sept. 25, 2023

Language: Английский

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Recent advancements of solid-state emissive carbon dots: A review

Coordination Chemistry Reviews, Journal Year: 2023, Volume and Issue: 498, P. 215469 - 215469

Published: Sept. 29, 2023

Language: Английский

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Tailored Fabrication of Full‐Color Ultrastable Room‐Temperature Phosphorescence Carbon Dots Composites with Unexpected Thermally Activated Delayed Fluorescence

Advanced Materials, Journal Year: 2024, Volume and Issue: 36(27)

Published: April 23, 2024

Abstract The development of single‐system materials that exhibit both multicolor room‐temperature phosphorescence (RTP) and thermally activated delayed fluorescence (TADF) with tunable after glow colors channels is challenging. In this study, four metal‐free carbon dots (CDs) are developed through structural tailoring, panchromatic high‐brightness RTP achieved via strong chemical encapsulation in urea. maximum lifetime quantum yield reaches 2141 ms 56.55%, respectively. Moreover, CDs‐IV@urea, prepared coreshell interaction engineering, exhibits a dual afterglow red green TADF. degree conjugation functional groups precursors affects the binding interactions nitrogen cladding on CDs, which turn stabilizes triplet energy levels gap between S 1 T (Δ E ST ) to induce RTP. enhanced wrapping lowers Δ , promoting reverse intersystem crossing, leads This fully state, thus stabilizing material water, even extreme environments such as acids oxidants. These tested multicolor, time, temperature multiencryption well vivo bioimaging. Hence, these have promising practical applications information security biomedical diagnosis treatment.

Language: Английский

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Machine learning-guided realization of full-color high-quantum-yield carbon quantum dots

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

Published: June 6, 2024

Abstract Carbon quantum dots (CQDs) have versatile applications in luminescence, whereas identifying optimal synthesis conditions has been challenging due to numerous parameters and multiple desired outcomes, creating an enormous search space. In this study, we present a novel multi-objective optimization strategy utilizing machine learning (ML) algorithm intelligently guide the hydrothermal of CQDs. Our closed-loop approach learns from limited sparse data, greatly reducing research cycle surpassing traditional trial-and-error methods. Moreover, it also reveals intricate links between target properties unifies objective function optimize like full-color photoluminescence (PL) wavelength high PL yields (PLQY). With only 63 experiments, achieve fluorescent CQDs with PLQY exceeding 60% across all colors. study represents significant advancement ML-guided synthesis, setting stage for developing new materials properties.

Language: Английский

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