Development of an organic dye solution for laser cooling by anti-Stokes fluorescence

2001 ◽  
Vol 667 ◽  
Author(s):  
Jarett L. Bartholomew ◽  
Peter A. DeBarber ◽  
Bauke Heeg ◽  
Garry Rumbles
Keyword(s):  
Laser Cooling ◽  
Organic Dye ◽  
Quantum Yields ◽  
Long Wavelength ◽  
Fluorescence Quantum Yields ◽  
Optical Cooling ◽  
Doped Glasses ◽  
Anti Stokes ◽  
Rhodamine 101 ◽  
Dye Solutions

ABSTRACTSeveral independent groups have observed optical cooling by means of anti-Stokes luminescence in condensed media. The most promising materials are grouped into two categories: ion-doped glasses and organic dye solutions. It is this latter group that we focus our efforts on. Recent studies by our group show that irradiating a solution of rhodamine 101 in the long wavelength wing of the absorption spectrum results in the observation of optical cooling. To improve upon the initial observation of a few degree drop in temperature requires a better understanding of the conditions and phenomena leading to anti-Stokes luminescence in dye solutions. We develop a thermal lensing experiment to obtain fluorescence quantum yields of various dye solutions. The importance of concentration, choice of solvent, deuteration, and acidification are discussed.

scholarly journals Progress in laser cooling semiconductor nanocrystals and nanostructures

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Shubin Zhang ◽  
Maksym Zhukovskyi ◽  
Boldizsár Jankó ◽  
Masaru Kuno
Keyword(s):  
Condensed Phase ◽  
Laser Cooling ◽  
Semiconductor Nanocrystals ◽  
Critical Parameters ◽  
Quantum Yields ◽  
Charge Carrier Dynamics ◽  
Optical Cooling ◽  
Potential System ◽  
Two Parameters ◽  
Near Future

Abstract Over the past two decades, there have been sizable efforts to realize condensed phase optical cooling. To date, however, there have been no verifiable demonstrations of semiconductor-based laser cooling. Recently, advances in the synthesis of semiconductor nanostructures have led to the availability of high-quality semiconductor nanocrystals, which possess superior optical properties relative to their bulk counterparts. In this review, we describe how these nanostructures can be used to demonstrate condensed phase laser cooling. We begin with a description of charge carrier dynamics in semiconductor nanocrystals and nanostructures under both above gap and below-gap excitation. Two critical parameters for realizing laser cooling are identified: emission quantum yield and upconversion efficiency. We report the literature values of these two parameters for different nanocrystal/nanostructure systems as well as the measurement approaches used to estimate them. We identify CsPbBr3 nanocrystals as a potential system by which to demonstrate verifiable laser cooling given their ease of synthesis, near-unity emission quantum yields and sizable upconversion efficiencies. Feasibility is further demonstrated through numerical simulations of CsPbBr3 nanocrystals embedded in an aerogel matrix. Our survey generally reveals that optimized semiconductor nanocrystals and nanostructures are poised to demonstrate condensed phase laser cooling in the near future.

Long-Wavelength-Absorbing and -Emitting Carbostyrils with High Fluorescence Quantum Yields

1999 ◽  
Vol 82 (9) ◽  
pp. 1408-1417 ◽  
Author(s):  
Georg Uray ◽  
Karlheinz S. Niederreiter ◽  
Ferdinand Belaj ◽  
Walter M. F. Fabian
Keyword(s):  
Quantum Yields ◽  
Long Wavelength ◽  
Fluorescence Quantum Yields ◽  
High Fluorescence

Demonstration of Net Laser Cooling in a Semiconductor

2013 ◽  
Vol 02 (02) ◽  
pp. 27-28
Author(s):  
Dehui Li ◽  
Jun Zhang ◽  
Qihua Xiong
Keyword(s):  
Rare Earth ◽  
Laser Cooling ◽  
Energy Levels ◽  
Lattice Vibrations ◽  
High Crystalline Quality ◽  
Direct Band Gap ◽  
Doped Glasses ◽  
Direct Band ◽  
Anti Stokes ◽  
Rare Earth Doped

Laser cooling of solids was first proposed by Pringsheim in 1929, more than 30 years before the invention of laser. With the advantages of being compact and free of vibration and cryogen, the laser cooling of solids shows very promising applications such as all solid-state cryocoolers and atheraml lasers. The basic principle of laser cooling in solids is based on the anti-Stokes luminescence, during which the emitted photons carry more energy than the incident photons. The thermal energy contained in lattice vibrations in solids is carried away by the emitted photons during the anti-Stokes luminescence processes resulting in the cooling of solids. To achieve net laser cooling, there are very strict requirements for materials: high external quantum efficiency, high crystalline quality and properly spaced energy levels. So far, the materials suitable for laser cooling are confined to rare-earth doped glasses or direct band gap semiconductors due to those special requirements.

scholarly journals Arylisoquinoline-derived organoboron dyes with a triaryl skeleton show dual fluorescence

2019 ◽  
Vol 15 ◽  
pp. 2612-2622
Author(s):  
Vânia F Pais ◽  
Tristan Neumann ◽  
Ignacio Vayá ◽  
M Consuelo Jiménez ◽  
Abel Ros ◽  
...  
Keyword(s):  
Emission Band ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash ◽  
Quantum Yields ◽  
Triplet States ◽  
Dual Emission ◽  
Long Wavelength ◽  
Fluorescence Quantum Yields ◽  
Wavelength Emission

Four new dyes that derive from borylated arylisoquinolines were prepared, containing a third aryl residue (naphthyl, 4-methoxynaphthyl, pyrenyl or anthryl) that is linked via an additional stereogenic axis. The triaryl cores were synthesized by Suzuki couplings and then transformed into boronic acid esters by employing an Ir(I)-catalyzed reaction. The chromophores show dual emission behavior, where the long-wavelength emission band can reach maxima close to 600 nm in polar solvents. The fluorescence quantum yields of the dyes are generally in the range of 0.2–0.4, reaching in some cases values as high as 0.5–0.6. Laser-flash photolysis provided evidence for the existence of excited triplet states. The dyes form fluoroboronate complexes with fluoride anions, leading to the observation of the quenching of the long-wavelength emission band and ratiometric response by the build-up of a hypsochromically shifted emission signal.

ChemInform Abstract: Long-Wavelength-Absorbing and -Emitting Carbostyrils with High Fluorescence Quantum Yields.

ChemInform ◽  
2010 ◽  
Vol 31 (1) ◽  
pp. no-no
Author(s):  
Georg Uray ◽  
Karlheinz S. Niederreiter ◽  
Ferdinand Belaj ◽  
Walter M. F. Fabian
Keyword(s):  
Quantum Yields ◽  
Long Wavelength ◽  
Fluorescence Quantum Yields ◽  
High Fluorescence

Limiting the intensity of femtosecond pulses with anti-stokes excitation of organic dye solutions

2010 ◽  
Vol 53 (3) ◽  
pp. 270-275
Author(s):  
V. A. Svetlichnyi ◽  
Yu. P. Meshalkin ◽  
A. V. Kirpichnikov ◽  
E. V. Pestryakov
Keyword(s):  
Organic Dye ◽  
Femtosecond Pulses ◽  
Anti Stokes ◽  
Dye Solutions

Observation of anti-Stokes fluorescence in organic dye solutions

1972 ◽  
Vol 8 (6) ◽  
pp. 527-528 ◽  
Author(s):  
M. Chang ◽  
S. Elliott ◽  
T. Gustafson ◽  
C. Hu ◽  
R. Jain
Keyword(s):  
Organic Dye ◽  
Anti Stokes ◽  
Dye Solutions

scholarly journals Accelerated Design of Near-Infrared-II Molecular Fluorophores via First-Principles Understanding and Machine Learning

2021 ◽  
Author(s):  
Shidang Xu ◽  
Pengfei Cai ◽  
Jiali Li ◽  
Xianhe Zhang ◽  
Xianglong Liu ◽  
...  
Keyword(s):  
Near Infrared ◽  
Energy Gap ◽  
Recent Decade ◽  
Quantum Yields ◽  
Chemical Library ◽  
Practical Applications ◽  
Long Wavelength ◽  
Fluorescence Quantum Yields ◽  
Wide Range ◽  
Fundamental Research

Organic molecular fluorophores in the second near-infrared window (NIR-II) have attracted much attention in the recent decade due to their great potentials in both fundamental research and practical applications. This is especially true for biomedical research, owing to their deep light penetration depth and low bioluminescence background at the long wavelength. However, the fluorescence quantum yields (QY) of most NIR-II materials are very low, which are not ideal for practical applications. Although there is a growing need to discover new NIR-II fluorophores, most of them were designed based on experience, and the structures were limited to few molecular motifs. Herein, we report the design of high QY NIR-II fluorophores in solutions based on enhancing the rigidity of the conjugated backbones, which could be quantified by the Seminario method. A deep neural network was trained to predict the HOMO-LUMO energy gaps for a chemical library of NIR-II backbone structures. Hundreds of new NIR-II cores with low energy gap were discovered, and eight of them across different acceptor cores are found to have relatively rigid conjugated backbones. With further molecular processing or formulation, the proposed new fluorophores should boost the development of NIR-II materials for applications in a wide range of fields.

Conjugated-linker dependence of the photophysical properties and electronic structure of chlorin dyads

2021 ◽  
pp. A-Y
Author(s):  
Hyun Suk Kang ◽  
Andrius Satraitis ◽  
Adam Meares ◽  
Ganga Viswanathan Bhagavathy ◽  
James R. Diers ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Excited State ◽  
Photophysical Properties ◽  
Bathochromic Shift ◽  
Fluorescence Yield ◽  
Quantum Yields ◽  
Design Strategies ◽  
Long Wavelength ◽  
Fluorescence Quantum Yields ◽  
Wavelength Absorption

The synthesis, photophysical properties and electronic structure of seven new chlorin dyads and associated benchmark monomers are described. Each dyad contains two identical chlorins linked at the macrocycle [Formula: see text]-pyrrole 13-position. The extent of electronic communication between chlorin constituents depends on the nature of the conjugated linker. The communication is assessed by modification of prominent ground-state absorption and redox properties, rate constants and yields of excited-state decay processes, and molecular-orbital characteristics. Relative to the benchmark monomers, the chlorin dyads in toluene exhibit a substantial bathochromic shift of the long-wavelength absorption band (30 nm average), two-fold increased radiative rate constant [average (10 ns)[Formula: see text] vs. (22 ns)[Formula: see text]], reduced singlet excited-state lifetimes (average 5.0 ns vs. 8.2 ns), and increased fluorescence quantum yields (average 0.56 vs. 0.42). The excited-state lifetime and fluorescence yield for the chlorin dyad with a benzothiadiazole linker are reduced substantially in benzonitrile vs. toluene due largely to [Formula: see text]25-fold accelerated internal conversion. The results aid design strategies for molecular architectures that may find utility in solar-energy conversion and photomedicine.

The redox properties of ferrocenyl-substituted aryl azines

2002 ◽  
Vol 80 (3) ◽  
pp. 250-262 ◽  
Author(s):  
Vittorio A Sauro ◽  
Mark S Workentin
Keyword(s):  
Cyclic Voltammetry ◽  
Radical Anion ◽  
General Characteristic ◽  
Redox Properties ◽  
Quantum Yields ◽  
X Ray ◽  
Long Wavelength ◽  
Fluorescence Quantum Yields ◽  
Reduction Potentials ◽  
Reversible Reduction

A series of ferrocenyl substituted azines (1-Fc/Ar, where Ar = 4-NO2C6H4, 4-CNC6H4, 4-OCH3C6H4, C5H4N, ferrocene, anthracene, and pyrene) were investigated by electrochemical and photochemical techniques. All the 1-Fc/Ar exhibited oxidation waves within 60 mV of each other, consistent with the expected oxidation of the ferrocene moiety. The reduction properties of 1-Fc/Ar is governed by the nature of the Ar substituent. The standard reduction potentials suggest that ferrocene has comparable electron donating abilities as a 4-methoxyphenyl and 4-dimethyl aminophenyl group. The anthracenyl azines exhibit one-electron reversible reduction followed by dimerization of the radical anion resulting in dimerization rate constants (kd) between 5.1 × 104 and 1.5 × 105 M–1 s–1. 1-Fc/Anth and related azines undergo photochemical E/Z isomerization of the C=N bonds to produce E/Z and Z/Z isomers from the thermodynamically most stable E/E form. Fluorescence at 77 K, was observed for these compounds only after long- wavelength irradiation to produce a mixture of E/E, E/Z, and Z/Z isomers. Fluorescence quantum yields of 0.042, 0.090, and 0.176 were determined for 2-Anth/H, 2-Anth/Anth, and 1-Fc/Anth, respectively. The electrochemical, photochemical, and X-ray data suggest that the azine unit is a conjugation "limiter" and may be a general characteristic of azine molecules.Key words: azines, electrochemistry, cyclic voltammetry, reduction, electron transfer.

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