ChemInform Abstract: Triplet-Triplet Annihilation Based Upconversion: From Triplet Sensitizers and Triplet Acceptors to Upconversion Quantum Yields.

ChemInform ◽  
2012 ◽  
Vol 43 (12) ◽  
pp. no-no
Author(s):  
Jianzhang Zhao ◽  
Shaomin Ji ◽  
Huimin Guo
Keyword(s):  
Quantum Yields ◽  
Triplet Triplet Annihilation

Highly efficient deep-blue fluorescent OLEDs based on anthracene derivatives with a triplet–triplet annihilation mechanism

2021 ◽  
Author(s):  
Zilong Wu ◽  
Shaoxin Song ◽  
Xiangyu Zhu ◽  
Hao Chen ◽  
Jiajin Chi ◽  
...  
Keyword(s):  
Quantum Yields ◽  
Carbazole Derivatives ◽  
Highly Efficient ◽  
Deep Blue ◽  
Anthracene Derivatives ◽  
Triplet Triplet Annihilation

New deep-blue molecules compromised of tert-butyl modified anthracene, p-benzonitrile, and carbazole derivatives provide external quantum yields of 7.03% and 7.28% in non-doped and doped deep-blue OLEDs, respectively.

H2O2-activated triplet–triplet annihilation upconversion via modulation of the fluorescence quantum yields of the triplet acceptor and the triplet–triplet-energy-transfer efficiency

2015 ◽  
Vol 51 (62) ◽  
pp. 12403-12406 ◽  
Author(s):  
Renjie Tao ◽  
Jianzhang Zhao ◽  
Fangfang Zhong ◽  
Caishun Zhang ◽  
Wenbo Yang ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Energy Transfer Efficiency ◽  
Transfer Efficiency ◽  
Quantum Yields ◽  
Fluorescent Product ◽  
Triplet Energy ◽  
Fluorescence Quantum Yields ◽  
Triplet Energy Transfer ◽  
Triplet Triplet Annihilation

H2O2-activatable TTA upconversion was achieved with non-fluorescent 9,10-bis(diphenylphosphino)anthracene as a triplet acceptor/emitter, which can be oxidized to a fluorescent product by H2O2.

scholarly journals Approaching the Spin-Statistical Limit in Visible-to-UV Photon Upconversion

2021 ◽  
Author(s):  
Axel Olesund ◽  
Jessica Johnsson ◽  
Fredrik Edhborg ◽  
Shima Ghasemi ◽  
Kasper Moth-Poulsen ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Transient Absorption ◽  
High Energy ◽  
Delayed Fluorescence ◽  
Photochemical Reactions ◽  
Quantum Yields ◽  
Great Promise ◽  
Time Resolved ◽  
Statistical Limit ◽  
Triplet Triplet Annihilation

Triplet-triplet annihilation photon upconversion (TTA-UC) is a process in which triplet excitons combine to form emissive singlets, and holds great promise to improve the spectral match in solar energy and biological applications. While high TTA-UC quantum yields has been reported for e.g., red-to-green TTA-UC systems there are only a few examples of visible-to-UV transformations in which the quantum yield reaches 10%. In this study we investigate the performance of six annihilators when paired with the sensitizer 2,3,5,6-tetra(9H-carbazol-9-yl)benzonitrile (4CzBN), a purely organic compound that exhibits thermally activated delayed fluorescence (TADF). We report a record-setting TTA-UC quantum yield of 16.8% (out of a 50% maximum) for 1,4-bis((triisopropylsilyl)ethynyl)naphthalene (TIPS-Naph), demonstrating the first example of a visible-to-UV TTA-UC system approaching the classical spin-statistical limit of 20%. Three other annihilators, of which 2,5-diphenylfuran (PPF) has never been used for TTA-UC previously, also showed impressive performances with TTA-UC quantum yields above 12%. In addition, a new method to determine the rate constant of triplet-triplet annihilation is proposed in which only time-resolved emission measurements are needed, circumventing the need for more challenging transient absorption measurements. The results reported herein represent an important step towards highly efficient visible-to-UV TTA-UC systems which hold great potential for driving high-energy photochemical reactions.

Absolute Method to Certify Quantum Yields of Photon Upconversion via Triplet–Triplet Annihilation

2019 ◽  
Vol 123 (46) ◽  
pp. 10197-10203 ◽  
Author(s):  
Nobuhiro Yanai ◽  
Kengo Suzuki ◽  
Taku Ogawa ◽  
Yoichi Sasaki ◽  
Naoyuki Harada ◽  
...  
Keyword(s):  
Quantum Yields ◽  
Absolute Method ◽  
Triplet Triplet Annihilation

Low-Power Triplet-Triplet Annihilation Upconversion with a New Anthracene Derivatives

2016 ◽  
Vol 852 ◽  
pp. 1265-1270
Author(s):  
Sai Jiang Zhu ◽  
Chang Qing Ye ◽  
Yan Fu ◽  
Zuo Qing Liang ◽  
Xiao Mei Wang
Keyword(s):  
Quantum Yield ◽  
Low Power ◽  
Power Density ◽  
High Efficiency ◽  
Excitation Power ◽  
Quantum Yields ◽  
Excitation Power Density ◽  
High Quantum ◽  
Anthracene Derivatives ◽  
Triplet Triplet Annihilation

Two new anthracene derivatives were synthesized as emitter for low power triplet-triplet annihilation upconversion. Compared with anthracene, the emitter exhibits high quantum yields up to 85%. Pd (II) tetraphenylporphyrin which was selected as the sensitizer with the existence of BBA in DMF, We find a pretty high efficiency (Φuc=21.9%) of the upconversion fluorescence at 532nm with a low excitation power density of 0.5w/cm2.With the comparison of Anthracene, BBA and BTPA systems, quantum yield of the emitter is very important to the improving of the efficiency of upconversion.

Highly Luminescent 4-Pyridyl-Extended Dithieno[3,2-b:2′,3′-d]phospholes

2020 ◽  
Author(s):  
Thomas Baumgartner ◽  
Paul Demay-Drouhard
Keyword(s):  
Electrochemical Properties ◽  
Quantum Yields

The unexpectedly challenging synthesis of 4-pyridyl-extended dithienophospholes is reported. The optical and electrochemical properties of the phosphoryl-bridged species were studied experimentally and computationally, and their properties compared to their non-<i>P</i>-bridged congeners. The 4-pyridyl-extended dithieno-phospholes display quantitative luminescence quantum yields in solution.<br><br>

Highly Luminescent 4-Pyridyl-Extended Dithieno[3,2-b:2′,3′-d]phospholes

2020 ◽  
Author(s):  
Thomas Baumgartner ◽  
Paul Demay-Drouhard
Keyword(s):  
Electrochemical Properties ◽  
Quantum Yields

The unexpectedly challenging synthesis of 4-pyridyl-extended dithienophospholes is reported. The optical and electrochemical properties of the phosphoryl-bridged species were studied experimentally and computationally, and their properties compared to their non-<i>P</i>-bridged congeners. The 4-pyridyl-extended dithieno-phospholes display quantitative luminescence quantum yields in solution.<br><br>

High-Temperature Synthesis of CdSe-Based Core/Shell, Core/Shell/Shell, and Core/Graded-Shell Nanoplatelets for Stable and Efficient Narrowband Emitters

2019 ◽  
Author(s):  
Aurelio A. Rossinelli ◽  
Henar Rojo ◽  
Aniket S. Mule ◽  
Marianne Aellen ◽  
Ario Cocina ◽  
...  
Keyword(s):  
Quantum Dots ◽  
High Temperature ◽  
Equilibrium Shape ◽  
Size Variation ◽  
Crystal Defects ◽  
Atomic Scale ◽  
Quantum Yields ◽  
Core Shell ◽  
Compositional Gradient ◽  
High Quality

<div>Colloidal semiconductor nanoplatelets exhibit exceptionally narrow photoluminescence spectra. This occurs because samples can be synthesized in which all nanoplatelets share the same atomic-scale thickness. As this dimension sets the emission wavelength, inhomogeneous linewidth broadening due to size variation, which is always present in samples of quasi-spherical nanocrystals (quantum dots), is essentially eliminated. Nanoplatelets thus offer improved, spectrally pure emitters for various applications. Unfortunately, due to their non-equilibrium shape, nanoplatelets also suffer from low photo-, chemical, and thermal stability, which limits their use. Moreover, their poor stability hampers the development of efficient synthesis protocols for adding high-quality protective inorganic shells, which are well known to improve the performance of quantum dots. <br></div><div>Herein, we report a general synthesis approach to highly emissive and stable core/shell nanoplatelets with various shell compositions, including CdSe/ZnS, CdSe/CdS/ZnS, CdSe/Cd<sub>x</sub>Zn<sub>1–x</sub>S, and CdSe/ZnSe. Motivated by previous work on quantum dots, we find that slow, high-temperature growth of shells containing a compositional gradient reduces strain-induced crystal defects and minimizes the emission linewidth while maintaining good surface passivation and nanocrystal uniformity. Indeed, our best core/shell nanoplatelets (CdSe/Cd<sub>x</sub>Zn<sub>1–x</sub>S) show photoluminescence quantum yields of 90% with linewidths as low as 56 meV (19.5 nm at 655 nm). To confirm the high quality of our different core/shell nanoplatelets for a specific application, we demonstrate their use as gain media in low-threshold ring lasers. More generally, the ability of our synthesis protocol to engineer high-quality shells can help further improve nanoplatelets for optoelectronic devices.</div>

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