A5018465488- Quantum Dots Synthesis And Properties
- Perovskite Materials and Applications
- Luminescence and Fluorescent Materials
- Luminescence Properties of Advanced Materials
- Chalcogenide Semiconductor Thin Films
- Catalytic C–H Functionalization Methods
- Organic Light-Emitting Diodes Research
- Metal-Organic Frameworks: Synthesis and Applications
- Radical Photochemical Reactions
- Organic Electronics and Photovoltaics
- Catalytic Cross-Coupling Reactions
- Oxidative Organic Chemistry Reactions
- Advanced Synthetic Organic Chemistry
- Covalent Organic Framework Applications
- Nonlinear Optical Materials Studies
- Photochromic and Fluorescence Chemistry
- Advanced biosensing and bioanalysis techniques
- Synthetic Organic Chemistry Methods
- Molecular Junctions and Nanostructures
- Sulfur-Based Synthesis Techniques
- Synthesis and Catalytic Reactions
- Lanthanide and Transition Metal Complexes
- Asymmetric Hydrogenation and Catalysis
- Advanced Photocatalysis Techniques
- Photochemistry and Electron Transfer Studies
Chinese Academy of Sciences
1997-2024
University of Chinese Academy of Sciences
2024
Technical Institute of Physics and Chemistry
1997-2024
Dalian Maritime University
2024
Lawrence Berkeley National Laboratory
2023
National Renewable Energy Laboratory
2020-2022
King Abdullah University of Science and Technology
2021
University of California, Riverside
2014-2020
Lafayette College
2018-2019
Wuhan University
2015-2018
The ability to upconvert two low energy photons into one high photon has potential applications in solar energy, biological imaging, and data storage. In this Letter, CdSe PbSe semiconductor nanocrystals are combined with molecular emitters (diphenylanthracene rubrene) both the visible near-infrared spectral regions. Absorption of by is followed transfer triplet states, which then undergo triplet–triplet annihilation create singlet states that emit upconverted light. By using conjugated...
Third generation photovoltaics are inexpensive modules that promise power conversion efficiencies exceeding the thermodynamic Shockley-Queisser limit, perhaps by using up- or down-converters, intermediate band solar cells, tandem hot carrier devices, multiexciton generation. Here, we report efficient upconversion of infrared to visible light at excitation densities below flux. Colloidally synthesized core-shell lead sulfide-cadmium sulfide nanocrystals in combination with tetracene...
Molecular control of energy transfer is an attractive proposition because it allows chemists to synthetically tweak various kinetic and thermodynamic factors. In this Perspective, we examine between semiconductor nanocrystals (NCs) π-conjugated molecules, focusing on the transmitter ligand at organic–inorganic interface. Efficient triplet excitons across interface photons be directed for effective use entire solar spectrum. For example, a photon upconversion system composed NCs as...
Herein we report the first example of nanocrystal (NC) sensitized triplet–triplet annihilation based photon upconversion from visible to ultraviolet (vis-to-UV).
Optical energy can be transformed into electricity, photons, and chemical bonds using colloidal quantum dots as the scaffold.
We investigate the parameters affecting upconversion of visible light in a hybrid organic–inorganic system based on CdSe nanocrystal (NC) sensitizers, 9-anthracene carboxylic acid (9-ACA) transmitter, and diphenylanthracene (DPA) annihilator. Seven wurtzite NCs ranging photoluminescence quantum yield (PLQY) from 2.0% to 11%, diameter 2.7 5.1 nm, were used combination with 9-ACA DPA molecules. Using nm NCs, we show that has quadratic linear dependence NC sensitizer concentration....
We investigate triplet energy transfer (TET) across variable-length aromatic oligo-p-phenylene and aliphatic bridges in a covalently linked CdSe nanocrystal (NC)–bridge–anthracene hybrid system. Photon upconversion measurements saturated 9,10-diphenylanthracene hexane solutions under air-free conditions at room temperature provided the steady-state rate of TET (ket) this interface. For flexible transmitters, ket is similar for different lengths bridges, suggesting that ligands bend backward....
Abstract A sub‐monolayer CdS shell on PbS quantum dots (QDs) enhances triplet energy transfer (TET) by suppressing competitive charge from QDs to molecules. The increases the linear photon upconversion yield (QY) 3.5 % for 5.0 PbS/CdS when functionalized with a tetracene acceptor, 5‐CT . While transient absorption spectroscopy reveals that both and show formation of (with rates 5.91±0.60 ns −1 1.03±0.09 respectively), ultrafast hole occurs only Although decreases TET rate, it efficiency...
We designed and synthesized a tetracene derivative 4-(tetracen-5-yl)benzoic acid (CPT) as transmitter ligand used in PbS/PbSe nanocrystal (NC) sensitized upconversion of near infrared (NIR) photons. Under optimal conditions, comparing CPT functionalized NCs with unfunctionalized sensitizers, the quantum yield (QY) was enhanced 81 times for 2.9 nm PbS from 0.021% to 1.7%, 11 2.5 PbSe 0.20% 2.1%. The surface density controls solubility QY. By increasing concentration exchange solution, number...
Photon upconversion has attracted enormous attention due to its wide range of applications in biological imaging, photocatalysis, and especially photovoltaics. Here, the effect quantum confinement on efficiency Dexter energy transfer from PbS PbSe nanocrystals (NCs) a rubrene acceptor is studied. A series experiments exploring relationship between NC size yield (QY) this hybrid platform show that occurs Marcus normal regime. By decreasing diameter 3.5 2.9 nm for 3.2 2.5 PbSe, relative QY...
Semiconductor nanocrystals (NCs) can initiate energy and charge transfer in multiple applications with their unique optical electronic properties. In particular, NCs are excellent light absorbers for initiating triplet (TET) to organic molecules, a key step triplet-fusion-based photon upconversion. Triplet across this inorganic-organic interface is one of the bottlenecks that currently limits overall upconversion quantum yield. Perspective, we summarize progress made past three years on...
Photon upconversion employing semiconductor nanocrystals (NCs) makes use of their large and tunable absorption to harvest light in the near-infrared (NIR) wavelengths as well small gap between singlet triplet excited states reduce energy losses. Here, we report highest QY (11.8%) thus far for conversion NIR yellow photons by improving quality PbS NC. This high was achieved using highly purified lead thiourea precursors. is 2.6 times higher than from NCs prepared with commercially available...
Quantum dot (QD)-sensitized photon upconversion follows a multi-step energy transfer process from the QD to transmitter ligand soluble annihilator. Using novel 10-R-anthracene-1,8-diphosphoric acid (R = octyl, 2-hexyldecyl, phenyl) with high binding affinity for CdSe surfaces, we demonstrate that is limited by annihilator efficiency. 1H NMR spectroscopy, these bidentate diphosphate ligands rapidly and irreversibly displace two carboxylate ligands. These mediate photoexcited QDs triplet...
ConspectusThe semiconductor-nanocrystal-sensitized, three-component upconversion system has made great strides over the past 5 years. The three components (i.e., triplet photosensitizer, mediator, and emitter) each play critical roles in determining input output photon energy overall quantum efficiency (QE). nanocrystal photosensitizer converts absorbed into singlet excitons then via intersystem crossing. mediator accepts exciton either direct Dexter-type transfer (TET) or sequential charge...
ConspectusThe Nobel Prize in Chemistry 2023 was awarded to Moungi G. Bawendi, Louis E. Brus, and Aleksey Ekimov for the discovery synthesis of quantum dots (QDs). Since QDs 1980s, endeavors have been put improve synthetic strategies with controllable sizes, crystal structures, surfaces. With development about half a century, used multiple optoelectronic applications, which are based on conversion between one photon exciton. In this case, photons energies lower than bandgap cannot be absorbed...
Two new UiO-68 type of Zr-MOFs featuring redox non-innocent catechol-based linkers different activities have been synthesized through a de novo mixed-linker strategy. Metalation the MOFs with Cu(II) precursors triggers reduction by phenyl-catechol groups to Cu(I) concomitant formation semiquinone radicals as evidenced EPR and XPS characterization. The MOF-supported catalysts are selective toward allylic oxidation cyclohexene it is found that presence in situ-generated species exhibits...
The first example of DMSO serving not only as a solvent but also an oxidant to promote the oxidation Cu(I) Cu(II) has been demonstrated. X-ray absorption and electron paramagnetic resonance evidence revealed single-electron redox process where could oxidize Cu(II). novel discovery guided rational design copper-catalyzed oxidative cyclization aryl ketones with styrenes furans, providing new method for synthesis multiaryl-substituted furans from cheap readily available starting materials.
A stable and structurally well-defined titanium alkoxide catalyst supported on a metal–organic-framework (MOF) of UiO-67 topology (ANL1-Ti(OiPr)2) was synthesized fully characterized by variety analytical spectroscopic techniques, including BET, TGA, PXRD, XAS, DRIFT, SEM, DFT computations. The Ti-functionalized MOF demonstrated active for the catalytic hydroboration wide range aldehydes ketones with HBpin as boron source. Compared to traditional homogeneous catalysts, ANL1-Ti(OiPr)2 is...
Efficient energy transfer is particularly important for multiexcitonic processes like singlet fission and photon upconversion. Observation of the transition from short-range tunneling to long-range hopping during triplet exciton CdSe nanocrystals anthracene reported here. This firmly supported by steady-state upconversion measurements, a direct proxy efficiency (TET), as well transient absorption measurements. When phenylene bridges are initially inserted between nanocrystal donor acceptor,...
Abstract Owing to the difficulty in comprehensively characterizing nanocrystal (NC) surfaces, clear guidance for ligand design is lacking. In this work, a series of bidentate bis(pyridine) anthracene isomers (2,3‐PyAn, 3,3‐PyAn, 2,2‐PyAn) that differ their binding geometries were designed find best complementary fit NC surface. The efficiency triplet energy transfer (TET) from CdSe donor diphenylanthracene (DPA) acceptor mediated by these was used as proxy efficacy orbital overlap and...
The combination of CdSe semiconductor nanocrystals with 9-anthracene carboxylic acid ligands can sensitize triplet–triplet annihilation on the emitter molecule diphenylanthracene. This hybrid system has recently been shown to upconvert visible light (532 nm) ultraviolet (420 (Huang, Z., et al. Nano Lett. 2015, 15, 5552–5557). In current paper, time-resolved photoluminescence measurements are used characterize kinetics energy transfer from exciton state triplet anthracene ligand. We find that...