A general strategy via charge transfer sensitization to achieve efficient NIR luminescence in lanthanide-doped NaGdS2 nanocrystals

2021 ◽  
Vol 9 (15) ◽  
pp. 5148-5153
Author(s):  
Shiteng Wang ◽  
Chunguang Zhang ◽  
Wei Zheng ◽  
Zhongliang Gong ◽  
Ping Huang ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Quantum Yields ◽  
General Strategy ◽  
Nir Luminescence ◽  
Co Doped

A strategy based on S2−-to-Yb3+ charge transfer sensitization is developed to achieve efficient NIR luminescence in Yb3+ singly-doped and Yb3+/Er3+ co-doped NaGdS2 nanocrystals with quantum yields up to 21.2% and 25.0%, respectively.

scholarly journals Solution-Processed OLEDs Based on Thermally Activated Delayed Fluorescence Copper(I) Complexes with Intraligand Charge-Transfer Excited State

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1125
Author(s):  
Teng Teng ◽  
Jinfan Xiong ◽  
Gang Cheng ◽  
Changjiang Zhou ◽  
Xialei Lv ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Density Functional ◽  
Delayed Fluorescence ◽  
Quantum Yields ◽  
Functional Theory ◽  
Solution Processed ◽  
Thermally Activated Delayed Fluorescence ◽  
Light Emitting ◽  
Thermally Activated ◽  
Wide Range

A new series of tetrahedral heteroleptic copper(I) complexes exhibiting efficient thermally-activated delayed fluorescence (TADF) in green to orange electromagnetic spectral regions has been developed by using D-A type N^N ligand and P^P ligands. Their structures, electrochemical, photophysical, and electroluminescence properties have been characterized. The complexes exhibit high photoluminescence quantum yields (PLQYs) of up to 0.71 at room temperature in doped film and the lifetimes are in a wide range of 4.3–24.1 μs. Density functional theory (DFT) calculations on the complexes reveal the lowest-lying intraligand charge-transfer excited states that are localized on the N^N ligands. Solution-processed organic light emitting diodes (OLEDs) based on one of the new emitters show a maximum external quantum efficiency (EQE) of 7.96%.

scholarly journals Tuning Multicolor Emission from a Single Fluorophore via Controlled Radical Polymerization-Mediated Charge Transfer

2020 ◽  
Author(s):  
Suiying Ye ◽  
Tian tian ◽  
Andrew J. Christofferson ◽  
Sofia Erikson ◽  
Jakub Jagielski ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Radical Polymerization ◽  
Molecular Design ◽  
Controlled Radical Polymerization ◽  
General Strategy ◽  
Fundamental Interest ◽  
Solid States ◽  
Emission Color ◽  
Theoretical Investigations ◽  
Practical Implications

<p>Tuning emission color of molecular fluorophores is of fundamental interest as it directly reflects the manipulation of excited states at the quantum-mechanical level. Despite recent progress in molecular design and engineering on single fluorophores, a systematic methodology to obtain multicolor emission in aggregated or solid states, which gives rise to practical implications in different fields, remains scarce. This is due to the complex interplay between the charge-transfer (CT) and singlet excitons. In this study, we present a general strategy to tune the emission color of a single-fluorophore aggregate by controlled radical polymerization-mediated charge transfer. Using a library of well-defined styrenic donor (D) polymers grown from an acceptor (A) fluorophore by atom transfer radical polymerization (ATRP), we found that the solid-state emission color can be fine-tuned by varying three molecular parameters: (i) the monomer substituent, (ii) the end-groups of the polymer, and (iii) the polymer chain length. Experimental and theoretical investigations reveal that the color tunability originates from the structurally dependent through-space charge transfer (TSCT) process that regulates CT energy. We further demonstrate that the polymer systems can be processed into thin films enabling versatile photolithography.</p>

scholarly journals Tuning Multicolor Emission from a Single Fluorophore via Controlled Radical Polymerization-Mediated Charge Transfer

2020 ◽  
Author(s):  
Suiying Ye ◽  
Tian tian ◽  
Andrew J. Christofferson ◽  
Sofia Erikson ◽  
Jakub Jagielski ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Radical Polymerization ◽  
Molecular Design ◽  
Controlled Radical Polymerization ◽  
General Strategy ◽  
Fundamental Interest ◽  
Solid States ◽  
Emission Color ◽  
Theoretical Investigations ◽  
Practical Implications

<p>Tuning emission color of molecular fluorophores is of fundamental interest as it directly reflects the manipulation of excited states at the quantum-mechanical level. Despite recent progress in molecular design and engineering on single fluorophores, a systematic methodology to obtain multicolor emission in aggregated or solid states, which gives rise to practical implications in different fields, remains scarce. This is due to the complex interplay between the charge-transfer (CT) and singlet excitons. In this study, we present a general strategy to tune the emission color of a single-fluorophore aggregate by controlled radical polymerization-mediated charge transfer. Using a library of well-defined styrenic donor (D) polymers grown from an acceptor (A) fluorophore by atom transfer radical polymerization (ATRP), we found that the solid-state emission color can be fine-tuned by varying three molecular parameters: (i) the monomer substituent, (ii) the end-groups of the polymer, and (iii) the polymer chain length. Experimental and theoretical investigations reveal that the color tunability originates from the structurally dependent through-space charge transfer (TSCT) process that regulates CT energy. We further demonstrate that the polymer systems can be processed into thin films enabling versatile photolithography.</p>

scholarly journals Tetraphenylethenyl-Modified 1,8-Naphthalimide Dye with Efficient Aggregation-Enhanced Emisssion, Solvatochromism and Intramolecular Charge Transfer Characteristics

2021 ◽  
Vol 2109 (1) ◽  
pp. 012025
Author(s):  
Qiuli Zhao ◽  
Qinghao Yang
Keyword(s):  
Charge Transfer ◽  
Intramolecular Charge Transfer ◽  
Quantum Yields ◽  
Transfer Property ◽  
Organic Luminophores ◽  
Emission Color ◽  
High Fluorescence ◽  
Photo Stability ◽  
Chemical Fields ◽  
Naphthalimide Dye

Abstract 1,8-naphthalimide (NI) dyes are one class of important organic luminophores with good photo-stability, high fluorescent quantum yields and broad emission color-tunability, which are widely used in biological and chemical fields. However, they exhibit bad ACQ property, which heavily limits their application in real word. Contrary to ACQ, tetraphenylethene (TPE) is an AIE luminogen. To eliminate the ACQ effect of NI, TPE was used as core and NI chromophores was used as peripheries to obtain a new dye TPEDNI. TPEDNI dye demonstrates typical aggregation-enhanced emission (AEE) characteristic with high fluorescence Φ>F, solid up to 100% in the film state, which is 24 times of that for its THF solution. Besides, TPEDNI exhibits marked solvatochromism, and the emission peak red-shifts from 505 nm in hexane to 610 nm in acetonitrile. TPENI also displays evident intramolecular charge transfer property in THF/water mixtures

Quantum yields of [W(CN)8]4? formation in charge-transfer photochemistry of octacyanotungstate (V)

1982 ◽  
Vol 7 (3) ◽  
pp. 131-134 ◽  
Author(s):  
Barbara Sieklucka ◽  
Aleksandra Kanas ◽  
Alina Samotus
Keyword(s):  
Charge Transfer ◽  
Quantum Yields

Colour-optimized quantum yields of Yb, Tm Co-doped upconversion nanocrystals

2019 ◽  
Vol 7 (2) ◽  
pp. 024001 ◽  
Author(s):  
Marco Kraft ◽  
Christian Würth ◽  
Emilia Palo ◽  
Tero Soukka ◽  
Ute Resch-Genger
Keyword(s):  
Quantum Yields ◽  
Upconversion Nanocrystals ◽  
Co Doped

Ag+-sensitized lanthanide luminescence in Ln3+ post-functionalized metal–organic frameworks and Ag+ sensing

2015 ◽  
Vol 3 (9) ◽  
pp. 4788-4792 ◽  
Author(s):  
Ji-Na Hao ◽  
Bing Yan
Keyword(s):  
Energy Transfer ◽  
Metal Organic Frameworks ◽  
Intramolecular Energy Transfer ◽  
Lanthanide Luminescence ◽  
New Class ◽  
Metal Organic ◽  
Nir Luminescence ◽  
Co Doped

A new class of lanthanide luminescent MOFs was constructed by encapsulating Ln3+ into the pores of MIL-121 (Ln3+@MIL-121). Ag+ was found to be able to greatly enhance the weak visible or NIR luminescence of Ln3+@MIL-121 since it can induce more efficient intramolecular energy transfer from the ligand to Ln3+ in Ag–Ln co-doped MOFs.

Influence of protonation of peripheral substituents on photophysical and photochemical properties of tetrapyrazinoporphyrazines

2010 ◽  
Vol 14 (07) ◽  
pp. 582-591 ◽  
Author(s):  
Veronika Novakova ◽  
Eva H. Mørkved ◽  
Miroslav Miletin ◽  
Petr Zimcik
Keyword(s):  
Charge Transfer ◽  
Sulfuric Acid ◽  
Singlet Oxygen ◽  
Electron Pair ◽  
Intramolecular Charge Transfer ◽  
Quantum Yields ◽  
Considerable Decrease ◽  
Fluorescence Quantum Yields ◽  
Photochemical Properties ◽  
Free Electron Pair

Octasubstituted zinc tetrapyrazinoporphyrazines with four N,N-dimethylaminophenyls and four phenyl or pyridin-3-yl substituents were synthesized and fully characterized. Their fluorescence quantum yields in DMF or pyridine were very low, almost undetectable, as a consequence of ultrafast intramolecular charge transfer. Titration of their DMF solutions with sulfuric acid led to increase of the fluorescence quantum yields by two orders of magnitude when the full protonation of peripheral substituents was achieved. Intramolecular charge transfer is no longer a favorable way of excited-state relaxation at full protonation of N,N-dimethylaminophenyl substituents because of loss of donor centers (free electron pair on its nitrogen). Similarly, singlet oxygen quantum yields also increased by two orders of magnitude when sulfuric acid was added to tetrapyrazinoporphyrazine solutions in DMF. Protonation at azomethine nitrogens of tetrapyrazinoporphyrazine macrocycle was observed at higher acid concentrations and it led to considerable decrease of fluorescence quantum yields. Octaphenyl zinc tetrapyrazinoporphyrazine and octa(pyridin-3-yl) zinc tetrapyrazinoporphyrazine were used as controls without intramolecular charge transfer. Their fluorescence and singlet oxygen quantum yields were high in DMF and decreased at higher concentrations of sulfuric acid due to protonation of azomethine nitrogens. The results suggest that the photophysical and photochemical properties of studied compounds may be controlled by changes of pH of medium.

UV and VUV Spectroscopy of ns2-type Ions Co-doped YBO3:Eu3+ Red Phosphor

2006 ◽  
Vol 916 ◽  
Author(s):  
L.L. Wang ◽  
Y.H. Wang ◽  
W.X. Hua
Keyword(s):  
Charge Transfer ◽  
Solid State ◽  
Absorption Band ◽  
Excitation Spectrum ◽  
Solid State Reaction ◽  
Vacuum Ultraviolet ◽  
Host Lattice ◽  
Red Phosphor ◽  
Vuv Spectroscopy ◽  
Co Doped

AbstractYBO3:5% Eu3+ co-doped with some ns2-type ions were synthesized by solid-state reaction and their luminescence properties under ultraviolet (UV) and vacuum ultraviolet (VUV) region were investigated. The results indicated that in the excitation spectrum of YBO3:5%Eu3+, the strong charge transfer (CT) band of Eu3+ was located in the UV region and the absorption band of the host lattice lay in the VUV region. When the ns2-type ions, such as Sn2+ and Sb3+(n=5), Tl+, Pb2+ and Bi3+(n=6) were co-doped into the host lattice of YBO3:5%Eu3+, the CTS band of Eu3+ was shifted. The intensity of the host lattice absorption band was improved with the incorporation of Tl+, Pb2+ or Bi3+, while decreased with Sn2+ or Sb3+. These luminescent phenomena were analyzed in detail and possible reasons were given.

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