651
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Wuister SF, de Mello Donega C, Meijerink A. Local-field effects on the spontaneous emission rate of CdTe and CdSe quantum dots in dielectric media. J Chem Phys 2004; 121:4310-5. [PMID: 15332980 DOI: 10.1063/1.1773154] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The refractive index dependence of the spontaneous emission rate is determined using organically capped CdSe and CdTe quantum dots as probes. The radiative lifetime of the exciton emission is measured in a variety of apolar solvents with refractive indices n between 1.37 and 1.50. It is demonstrated that quantum dots provide a model system for testing theories on the influence of local-field effects on the spontaneous emission rate. The experimentally observed influence of n on the radiative lifetime is smaller than predicted by well-known models for local-field corrections but is in good agreement with a recently developed fully microscopic model for the local-field enhancement of the spontaneous emission rate.
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Affiliation(s)
- Sander F Wuister
- Debye Institute, Chemistry of Condensed Matter, Utrecht University, P.O. Box 80 000, 3508 TA Utrecht, The Netherlands
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652
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Wuister SF, de Mello Donegá C, Meijerink A. Luminescence Temperature Antiquenching of Water-Soluble CdTe Quantum Dots: Role of the Solvent. J Am Chem Soc 2004; 126:10397-402. [PMID: 15315455 DOI: 10.1021/ja048222a] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Luminescence temperature antiquenching (LTAQ) is observed for water-soluble CdTe quantum dots (QDs) capped with aminoethanethiol (AET). The efficient exciton emission (quantum efficiency of approximately 40% at 300 K) is quenched almost completely as the QD solutions are cooled to below 230 K and is fully recovered around 270 K upon warming up to room temperature (LTAQ). Temperature-dependent lifetime measurements show that the quenching rate is high, resulting in an on/off behavior. No LTAQ is observed for CdTe QDs capped with aminoundecanethiol (AUT). The LTAQ is explained by the influence of solvent freezing on the surface of the QD core. Freezing of the solvation water molecules surrounding the QD will induce strain in the capping shell, due to the interaction between water and the charged heads of the capping molecules. Short carbon chains (AET) will propagate the strain to the QD surface, creating surface quenching states, whereas long and flexible chains (AUT) will dissipate the strain, thus avoiding surface distortion. Freezing-point depression by the addition of methanol results in a lowering of the transition temperature. Additional support is provided by the size dependence of the LTAQ: smaller particles, with higher local ionic strength due to a higher density of charged NH(3)(+) surface groups, experience a lower transition temperature due to stronger local freezing-point depression.
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Affiliation(s)
- Sander F Wuister
- Contribution from the Debye Institute, Condensed Matter and Interfaces, Utrecht University, Post Office Box 80 000, 3508 TA Utrecht, The Netherlands.
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653
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Castro SL, Bailey SG, Raffaelle RP, Banger KK, Hepp AF. Synthesis and Characterization of Colloidal CuInS2Nanoparticles from a Molecular Single-Source Precursor. J Phys Chem B 2004. [DOI: 10.1021/jp049107p] [Citation(s) in RCA: 375] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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654
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Müller F, Götzinger S, Gaponik N, Weller H, Mlynek J, Benson O. Investigation of Energy Transfer between CdTe Nanocrystals on Polystyrene Beads and Dye Molecules for FRET-SNOM Applications. J Phys Chem B 2004. [DOI: 10.1021/jp049183s] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Felix Müller
- Institute of Physics, Nano-Optics, Humboldt-University Berlin, Hausvogteiplatz 5-7, D-10117 Berlin, Germany, and Institute of Physical Chemistry, University of Hamburg, D-20146 Hamburg, Germany
| | - Stephan Götzinger
- Institute of Physics, Nano-Optics, Humboldt-University Berlin, Hausvogteiplatz 5-7, D-10117 Berlin, Germany, and Institute of Physical Chemistry, University of Hamburg, D-20146 Hamburg, Germany
| | - Nikolai Gaponik
- Institute of Physics, Nano-Optics, Humboldt-University Berlin, Hausvogteiplatz 5-7, D-10117 Berlin, Germany, and Institute of Physical Chemistry, University of Hamburg, D-20146 Hamburg, Germany
| | - Horst Weller
- Institute of Physics, Nano-Optics, Humboldt-University Berlin, Hausvogteiplatz 5-7, D-10117 Berlin, Germany, and Institute of Physical Chemistry, University of Hamburg, D-20146 Hamburg, Germany
| | - Jürgen Mlynek
- Institute of Physics, Nano-Optics, Humboldt-University Berlin, Hausvogteiplatz 5-7, D-10117 Berlin, Germany, and Institute of Physical Chemistry, University of Hamburg, D-20146 Hamburg, Germany
| | - Oliver Benson
- Institute of Physics, Nano-Optics, Humboldt-University Berlin, Hausvogteiplatz 5-7, D-10117 Berlin, Germany, and Institute of Physical Chemistry, University of Hamburg, D-20146 Hamburg, Germany
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655
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Kang EC, Ogura A, Kataoka K, Nagasaki Y. Preparation of Water-soluble PEGylated Semiconductor Nanocrystals. CHEM LETT 2004. [DOI: 10.1246/cl.2004.840] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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656
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Chen CY, Cheng CT, Yu JK, Pu SC, Cheng YM, Chou PT, Chou YH, Chiu HT. Spectroscopy and Femtosecond Dynamics of Type-II CdSe/ZnTe Core−Shell Semiconductor Synthesized via the CdO Precursor. J Phys Chem B 2004. [DOI: 10.1021/jp049177w] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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657
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Pinaud F, King D, Moore HP, Weiss S. Bioactivation and cell targeting of semiconductor CdSe/ZnS nanocrystals with phytochelatin-related peptides. J Am Chem Soc 2004; 126:6115-23. [PMID: 15137777 PMCID: PMC5715196 DOI: 10.1021/ja031691c] [Citation(s) in RCA: 362] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Synthetic phytochelatin-related peptides are used as an organic coat on the surface of colloidal CdSe/ZnS semiconductor nanocrystals synthesized from hydrophobic coordinating trioctyl phosphine oxide (TOPO) solvents. The peptides are designed to bind to the nanocrystals via a C-terminal adhesive domain. This adhesive domain, composed of multiple repeats of cysteines pairs flanked by hydrophobic 3-cyclohexylalanines, is followed by a flexible hydrophilic linker domain to which various bio-affinity tags can be attached. This surface coating chemistry results in small, buffer soluble, monodisperse peptide-coated nanoparticles with high colloidal stability and ensemble photophysical properties similar to those of TOPO-coated nanocrystals. Various peptide coatings are used to modulate the nanocrystal surface properties and to bioactivate the nanoparticles. CdSe/ZnS nanocrystals coated with biotinylated peptides efficiently bind to streptavidin and are specifically targeted to GPI-anchored avidin-CD14 chimeric proteins expressed on the membranes of live HeLa cells. This peptide coating surface chemistry provides a novel approach for the production of biocompatible photoluminescent nanocrystal probes.
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Affiliation(s)
- Fabien Pinaud
- Department of Chemistry & Biochemistry, University of California Los Angeles, Los Angeles, California 90095, USA.
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658
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Götzinger S, Menezes LDS, Benson O, Talapin DV, Gaponik N, Weller H, Rogach AL, Sandoghdar V. Confocal microscopy and spectroscopy of nanocrystals on a high-Qmicrosphere resonator. ACTA ACUST UNITED AC 2004. [DOI: 10.1088/1464-4266/6/2/005] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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659
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Wang H, Li X, Uehara M, Yamaguchi Y, Nakamura H, Miyazaki M, Shimizu H, Maeda H. Continuous synthesis of CdSe–ZnS composite nanoparticles in a microfluidic reactor. Chem Commun (Camb) 2004:48-9. [PMID: 14737326 DOI: 10.1039/b310644f] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
ZnS-coated CdSe composite particles have been continuously synthesized in a microfluidic reactor. By using this system, CdSe particles and a ZnS coating can be produced in sequence, and the particle size and layer thickness can be directly adjusted by the residence time. It demonstrated that the continuous synthesis in the microreactor was a simple and efficient way to prepare composite particles with different structures and determine the optimized experimental conditions.
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Affiliation(s)
- Hongzhi Wang
- Micro-space Chemistry Lab, National Institute of Advanced Industrial Science and Technology (AIST), 807-1 Shuku, Tosu, Saga 841-052, Japan
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660
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Ebenstein Y, Mokari T, Banin U. Quantum-Dot-Functionalized Scanning Probes for Fluorescence-Energy-Transfer-Based Microscopy. J Phys Chem B 2003. [DOI: 10.1021/jp036135j] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Y. Ebenstein
- Institute of Chemistry, the Farkas Center for Light Induced Processes, and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - T. Mokari
- Institute of Chemistry, the Farkas Center for Light Induced Processes, and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - U. Banin
- Institute of Chemistry, the Farkas Center for Light Induced Processes, and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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661
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Improved optical properties of CdS quantum dots by ligand exchange. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2003. [DOI: 10.1016/j.msec.2003.09.121] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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662
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Battaglia D, Li JJ, Wang Y, Peng X. Colloidal Two-Dimensional Systems: CdSe Quantum Shells and Wells. Angew Chem Int Ed Engl 2003. [DOI: 10.1002/ange.200352120] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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663
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Battaglia D, Li JJ, Wang Y, Peng X. Colloidal Two-Dimensional Systems: CdSe Quantum Shells and Wells. Angew Chem Int Ed Engl 2003; 42:5035-9. [PMID: 14595624 DOI: 10.1002/anie.200352120] [Citation(s) in RCA: 165] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- David Battaglia
- Dept. of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA
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664
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Li JJ, Wang YA, Guo W, Keay JC, Mishima TD, Johnson MB, Peng X. Large-Scale Synthesis of Nearly Monodisperse CdSe/CdS Core/Shell Nanocrystals Using Air-Stable Reagents via Successive Ion Layer Adsorption and Reaction. J Am Chem Soc 2003; 125:12567-75. [PMID: 14531702 DOI: 10.1021/ja0363563] [Citation(s) in RCA: 765] [Impact Index Per Article: 36.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Successive ion layer adsorption and reaction (SILAR) originally developed for the deposition of thin films on solid substrates from solution baths is introduced as a technique for the growth of high-quality core/shell nanocrystals of compound semiconductors. The growth of the shell was designed to grow one monolayer at a time by alternating injections of air-stable and inexpensive cationic and anionic precursors into the reaction mixture with core nanocrystals. The principles of SILAR were demonstrated by the CdSe/CdS core/shell model system using its shell-thickness-dependent optical spectra as the probes with CdO and elemental S as the precursors. For this reaction system, a relatively high temperature, about 220-240 degrees C, was found to be essential for SILAR to fully occur. The synthesis can be readily performed on a multigram scale. The size distribution of the core/shell nanocrystals was maintained even after five monolayers of CdS shell (equivalent to about 10 times volume increase for a 3.5 nm CdSe nanocrystal) were grown onto the core nanocrystals. The epitaxial growth of the core/shell structures was verified by optical spectroscopy, TEM, XRD, and XPS. The photoluminescence quantum yield (PL QY) of the as-prepared CdSe/CdS core/shell nanocrystals ranged from 20% to 40%, and the PL full-width at half-maximum (fwhm) was maintained between 23 and 26 nm, even for those nanocrystals for which the UV-vis and PL peaks red-shifted by about 50 nm from that of the core nanocrystals. Several types of brightening phenomena were observed, some of which can further boost the PL QY of the core/shell nanocrystals. The CdSe/CdS core/shell nanocrystals were found to be superior in comparison to the highly luminescent CdSe plain core nanocrystals. The SILAR technique reported here can also be used for the growth of complex colloidal semiconductor nanostructures, such as quantum shells and colloidal quantum wells.
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Affiliation(s)
- J Jack Li
- Department of Chemistry & Biochemistry, University of Arkansas, Fayetteville, Arkansas 72701, USA
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665
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Joo J, Na HB, Yu T, Yu JH, Kim YW, Wu F, Zhang JZ, Hyeon T. Generalized and facile synthesis of semiconducting metal sulfide nanocrystals. J Am Chem Soc 2003; 125:11100-5. [PMID: 12952492 DOI: 10.1021/ja0357902] [Citation(s) in RCA: 325] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report on the synthesis of semiconductor nanocrystals of PbS, ZnS, CdS, and MnS through a facile and inexpensive synthetic process. Metal-oleylamine complexes, which were obtained from the reaction of metal chloride and oleylamine, were mixed with sulfur. The reaction mixture was heated under appropriate experimental conditions to produce metal sulfide nanocrystals. Uniform cube-shaped PbS nanocrystals with particle sizes of 6, 8, 9, and 13 nm were synthesized. The particle size was controlled by changing the relative amount of PbCl(2) and sulfur. Uniform 11 nm sized spherical ZnS nanocrystals were synthesized from the reaction of zinc chloride and sulfur, followed by one cycle of size-selective precipitation. CdS nanocrystals that consist of rods, bipods, and tripods were synthesized from a reaction mixture containing a 1:6 molar ratio of cadmium to sulfur. Spherical CdS nanocrystals (5.1 nm sized) were obtained from a reaction mixture with a cadmium to sulfur molar ratio of 2:1. MnS nanocrystals with various sizes and shapes were synthesized from the reaction of MnCl(2) and sulfur in oleylamine. Rod-shaped MnS nanocrystals with an average size of 20 nm (thickness) x 37 nm (length) were synthesized from a 1:1 molar ratio of MnCl(2) and sulfur at 240 degrees C. Novel bullet-shaped MnS nanocrystals with an average size of 17 nm (thickness) x 44 nm (length) were synthesized from the reaction of 4 mmol of MnCl(2) and 2 mmol of sulfur at 280 degrees C for 2 h. Shorter bullet-shaped MnS nanocrystals were synthesized from a 3:1 molar ratio of MnCl(2) and sulfur. Hexagon-shaped MnS nanocrystals were also obtained. All of the synthesized nanocrystals were highly crystalline.
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Affiliation(s)
- Jin Joo
- National Creative Research Initiative Center for Oxide Nanocrystalline Materials and School of Chemical Engineering and the School of Materials Science and Engineering, Seoul National University, Seoul 151-744
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666
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Sharma SN, Pillai ZS, Kamat PV. Photoinduced Charge Transfer between CdSe Quantum Dots and p-Phenylenediamine. J Phys Chem B 2003. [DOI: 10.1021/jp034109f] [Citation(s) in RCA: 195] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Zeena S. Pillai
- Notre Dame Radiation Laboratory, Notre Dame, Indiana 46556-0579
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667
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Zhong X, Han M, Dong Z, White TJ, Knoll W. Composition-tunable Zn(x)Cd(1-x)Se nanocrystals with high luminescence and stability. J Am Chem Soc 2003; 125:8589-94. [PMID: 12848567 DOI: 10.1021/ja035096m] [Citation(s) in RCA: 252] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
High-quality Zn(x)Cd(1-x)Se nanocrystals have been successfully prepared at high temperature by incorporating stoichiometric amounts of Zn and Se into pre-prepared CdSe nanocrystals. With increasing Zn content, a composition-tunable emission across most of the visible spectrum has been demonstrated by a systematic blue-shift in emission wavelength. The photoluminescence (PL) properties for the obtained Zn(x)Cd(1-x)Se nanocrystals (PL efficiency of 70-85%, fwhm = 22-30 nm) are comparable to those for the best reported CdSe-based QDs. In particular, they also have good PL properties in the blue spectral range. Moreover, the alloy nanocrystals can retain their high luminescence (PL efficiency of over 40%) when dispersed in aqueous solutions and maintain a symmetric peak shape and spectral position under rigorous experimental conditions. A rapid alloying process was observed at a temperature higher than "alloying point". The mechanism of the high luminescence efficiency and stability of Zn(x)Cd(1-x)Se nanocrystals is explored.
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Affiliation(s)
- Xinhua Zhong
- Department of Materials Science, National University of Singapore, Singapore
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668
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Borchert H, Talapin DV, McGinley C, Adam S, Lobo A, de Castro ARB, Möller T, Weller H. High resolution photoemission study of CdSe and CdSe/ZnS core-shell nanocrystals. J Chem Phys 2003. [DOI: 10.1063/1.1580096] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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669
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Koberling F, Kolb U, Philipp G, Potapova I, Basché T, Mews A. Fluorescence Anisotropy and Crystal Structure of Individual Semiconductor Nanocrystals. J Phys Chem B 2003. [DOI: 10.1021/jp027800b] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Felix Koberling
- Institut für Physikalische Chemie, Universität Mainz, Mainz D-55099, Germany, and Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, Stuttgart D-70569, Germany
| | - Ute Kolb
- Institut für Physikalische Chemie, Universität Mainz, Mainz D-55099, Germany, and Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, Stuttgart D-70569, Germany
| | - Günther Philipp
- Institut für Physikalische Chemie, Universität Mainz, Mainz D-55099, Germany, and Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, Stuttgart D-70569, Germany
| | - Inga Potapova
- Institut für Physikalische Chemie, Universität Mainz, Mainz D-55099, Germany, and Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, Stuttgart D-70569, Germany
| | - Thomas Basché
- Institut für Physikalische Chemie, Universität Mainz, Mainz D-55099, Germany, and Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, Stuttgart D-70569, Germany
| | - Alf Mews
- Institut für Physikalische Chemie, Universität Mainz, Mainz D-55099, Germany, and Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, Stuttgart D-70569, Germany
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670
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Bailey RE, Nie S. Alloyed semiconductor quantum dots: tuning the optical properties without changing the particle size. J Am Chem Soc 2003; 125:7100-6. [PMID: 12783563 DOI: 10.1021/ja035000o] [Citation(s) in RCA: 405] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Alloyed semiconductor quantum dots (cadmium selenium telluride) with both homogeneous and gradient internal structures have been prepared to achieve continuous tuning of the optical properties without changing the particle size. Our results demonstrate that composition and internal structure are two important parameters that can be used to tune the optical and electronic properties of multicomponent, alloyed quantum dots. A surprising finding is a nonlinear relationship between the composition and the absorption/emission energies, leading to new properties not obtainable from the parent binary systems. With red-shifted light emission up to 850 nm and quantum yields up to 60%, this new class of alloyed quantum dots opens new possibilities in band gap engineering and in developing near-infrared fluorescent probes for in vivo molecular imaging and biomarker detection.
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Affiliation(s)
- Robert E Bailey
- Department of Biomedical Engineering and Chemistry, Emory University and Georgia Institute of Technology, 1639 Pierce Drive, Suite 2001, Atlanta, Georgia 30322, USA
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671
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Mekis I, Talapin DV, Kornowski A, Haase M, Weller H. One-Pot Synthesis of Highly Luminescent CdSe/CdS Core−Shell Nanocrystals via Organometallic and “Greener” Chemical Approaches. J Phys Chem B 2003. [DOI: 10.1021/jp0278364] [Citation(s) in RCA: 325] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ivo Mekis
- Institute of Physical Chemistry, University of Hamburg, Bundesstrasse 45, 20146 Hamburg, Germany
| | - Dmitri V. Talapin
- Institute of Physical Chemistry, University of Hamburg, Bundesstrasse 45, 20146 Hamburg, Germany
| | - Andreas Kornowski
- Institute of Physical Chemistry, University of Hamburg, Bundesstrasse 45, 20146 Hamburg, Germany
| | - Markus Haase
- Institute of Physical Chemistry, University of Hamburg, Bundesstrasse 45, 20146 Hamburg, Germany
| | - Horst Weller
- Institute of Physical Chemistry, University of Hamburg, Bundesstrasse 45, 20146 Hamburg, Germany
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672
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Barglik-Chory C, Münster A, Strohm H, Remenyi C, Müller G. Influence of synthesis parameters on the growth of CdS nanoparticles in colloidal solution and determination of growth kinetics using Karhunen–Loeve decomposition. Chem Phys Lett 2003. [DOI: 10.1016/s0009-2614(03)00706-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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673
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Borchert H, Dorfs D, McGinley C, Adam S, Möller T, Weller H, Eychmüller A. Photoemission Study of Onion Like Quantum Dot Quantum Well and Double Quantum Well Nanocrystals of CdS and HgS. J Phys Chem B 2003. [DOI: 10.1021/jp027485t] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Holger Borchert
- Institute of Physical Chemistry, University of Hamburg, Bundesstr. 45, 20146 Hamburg, Germany, and Hamburger Synchrotronstrahlungslabor HASYLAB at DESY, Notkestr. 85, 22603 Hamburg, Germany
| | - Dirk Dorfs
- Institute of Physical Chemistry, University of Hamburg, Bundesstr. 45, 20146 Hamburg, Germany, and Hamburger Synchrotronstrahlungslabor HASYLAB at DESY, Notkestr. 85, 22603 Hamburg, Germany
| | - Colm McGinley
- Institute of Physical Chemistry, University of Hamburg, Bundesstr. 45, 20146 Hamburg, Germany, and Hamburger Synchrotronstrahlungslabor HASYLAB at DESY, Notkestr. 85, 22603 Hamburg, Germany
| | - Sorin Adam
- Institute of Physical Chemistry, University of Hamburg, Bundesstr. 45, 20146 Hamburg, Germany, and Hamburger Synchrotronstrahlungslabor HASYLAB at DESY, Notkestr. 85, 22603 Hamburg, Germany
| | - Thomas Möller
- Institute of Physical Chemistry, University of Hamburg, Bundesstr. 45, 20146 Hamburg, Germany, and Hamburger Synchrotronstrahlungslabor HASYLAB at DESY, Notkestr. 85, 22603 Hamburg, Germany
| | - Horst Weller
- Institute of Physical Chemistry, University of Hamburg, Bundesstr. 45, 20146 Hamburg, Germany, and Hamburger Synchrotronstrahlungslabor HASYLAB at DESY, Notkestr. 85, 22603 Hamburg, Germany
| | - Alexander Eychmüller
- Institute of Physical Chemistry, University of Hamburg, Bundesstr. 45, 20146 Hamburg, Germany, and Hamburger Synchrotronstrahlungslabor HASYLAB at DESY, Notkestr. 85, 22603 Hamburg, Germany
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674
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Potapova I, Mruk R, Prehl S, Zentel R, Basché T, Mews A. Semiconductor nanocrystals with multifunctional polymer ligands. J Am Chem Soc 2003; 125:320-1. [PMID: 12517129 DOI: 10.1021/ja028641c] [Citation(s) in RCA: 128] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this letter, we describe the preparation of a versatile polymer ligand, which can be attached to CdSe/ZnS semiconductor nanocrystals via a phase transfer reaction. The ligand is based on a chain of reactive esters, which can, in principle, be substituted by any compound containing amino-functionalities. The polymer/nanocrystal complexes are characterized in terms of structure and photostability.
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Affiliation(s)
- Inga Potapova
- Institute of Physical Chemistry and Institute of Organic Chemistry, University of Mainz, Germany
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675
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676
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de Mello Donegá C, Hickey SG, Wuister SF, Vanmaekelbergh D, Meijerink A. Single-Step Synthesis to Control the Photoluminescence Quantum Yield and Size Dispersion of CdSe Nanocrystals. J Phys Chem B 2002. [DOI: 10.1021/jp027160c] [Citation(s) in RCA: 263] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Celso de Mello Donegá
- Debye Institute, Chemistry of Condensed Matter, Utrecht University, PO Box 80000, 3508TA Utrecht, The Netherlands
| | - Stephen G. Hickey
- Debye Institute, Chemistry of Condensed Matter, Utrecht University, PO Box 80000, 3508TA Utrecht, The Netherlands
| | - Sander F. Wuister
- Debye Institute, Chemistry of Condensed Matter, Utrecht University, PO Box 80000, 3508TA Utrecht, The Netherlands
| | - Daniel Vanmaekelbergh
- Debye Institute, Chemistry of Condensed Matter, Utrecht University, PO Box 80000, 3508TA Utrecht, The Netherlands
| | - Andries Meijerink
- Debye Institute, Chemistry of Condensed Matter, Utrecht University, PO Box 80000, 3508TA Utrecht, The Netherlands
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677
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Shevchenko EV, Talapin DV, Rogach AL, Kornowski A, Haase M, Weller H. Colloidal synthesis and self-assembly of CoPt(3) nanocrystals. J Am Chem Soc 2002; 124:11480-5. [PMID: 12236762 DOI: 10.1021/ja025976l] [Citation(s) in RCA: 279] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Reduction of platinum acetylacetonate and thermodecomposition of cobalt carbonyl in the presence of 1-adamantanecarboxylic acid were employed in different coordinating mixtures to produce monodisperse, highly crystalline CoPt(3) nanoparticles. The mean particle size can be varied from 1.5 to 7.2 nm by controlling the reaction conditions and the type of coordinating mixture. As-synthesized CoPt(3) particles represent single crystal domains and have chemically disordered face-centered cubic (fcc) structure. Nearly spherical CoPt(3) nanocrystals were found to assemble into two- (2D) and three-dimensional (3D) structures. An AB(5) type superlattice is observed by TEM after mixing two nanoparticle samples with different mean sizes. Slow precipitation led to the formation of facetted colloidal crystals with sizes up to 20 microm.
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Affiliation(s)
- Elena V Shevchenko
- Institute of Physical Chemistry, University of Hamburg, D-20146 Hamburg, Germany
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678
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Lebedkin S, Langetepe T, Sevillano P, Fenske D, Kappes MM. Novel Photophysical Properties of Gold Selenide Complexes: Photogeneration of Singlet Oxygen by [Au18Se8(dppe)6]Br2 and Near-Infrared Photoluminescence of [Au10Se4(dpppe)4]Br2. J Phys Chem B 2002. [DOI: 10.1021/jp021100p] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sergei Lebedkin
- Forschungszentrum Karlsruhe, Institut für Nanotechnologie, D-76021 Karlsruhe, Germany, Institut für Physikalische Chemie II, Universität Karlsruhe, D-76128 Karlsruhe, Germany, and Institut für Anorganische Chemie, Universität Karlsruhe, D-76128 Karlsruhe, Germany
| | - Timo Langetepe
- Forschungszentrum Karlsruhe, Institut für Nanotechnologie, D-76021 Karlsruhe, Germany, Institut für Physikalische Chemie II, Universität Karlsruhe, D-76128 Karlsruhe, Germany, and Institut für Anorganische Chemie, Universität Karlsruhe, D-76128 Karlsruhe, Germany
| | - Paloma Sevillano
- Forschungszentrum Karlsruhe, Institut für Nanotechnologie, D-76021 Karlsruhe, Germany, Institut für Physikalische Chemie II, Universität Karlsruhe, D-76128 Karlsruhe, Germany, and Institut für Anorganische Chemie, Universität Karlsruhe, D-76128 Karlsruhe, Germany
| | - Dieter Fenske
- Forschungszentrum Karlsruhe, Institut für Nanotechnologie, D-76021 Karlsruhe, Germany, Institut für Physikalische Chemie II, Universität Karlsruhe, D-76128 Karlsruhe, Germany, and Institut für Anorganische Chemie, Universität Karlsruhe, D-76128 Karlsruhe, Germany
| | - Manfred M. Kappes
- Forschungszentrum Karlsruhe, Institut für Nanotechnologie, D-76021 Karlsruhe, Germany, Institut für Physikalische Chemie II, Universität Karlsruhe, D-76128 Karlsruhe, Germany, and Institut für Anorganische Chemie, Universität Karlsruhe, D-76128 Karlsruhe, Germany
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679
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Gaponik N, Talapin DV, Rogach AL, Hoppe K, Shevchenko EV, Kornowski A, Eychmüller A, Weller H. Thiol-Capping of CdTe Nanocrystals: An Alternative to Organometallic Synthetic Routes. J Phys Chem B 2002. [DOI: 10.1021/jp025541k] [Citation(s) in RCA: 1347] [Impact Index Per Article: 61.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Nikolai Gaponik
- Institute of Physical Chemistry, University of Hamburg, Bundesstr. 45, 20146 Hamburg, Germany
| | - Dmitri V. Talapin
- Institute of Physical Chemistry, University of Hamburg, Bundesstr. 45, 20146 Hamburg, Germany
| | - Andrey L. Rogach
- Institute of Physical Chemistry, University of Hamburg, Bundesstr. 45, 20146 Hamburg, Germany
| | - Kathrin Hoppe
- Institute of Physical Chemistry, University of Hamburg, Bundesstr. 45, 20146 Hamburg, Germany
| | - Elena V. Shevchenko
- Institute of Physical Chemistry, University of Hamburg, Bundesstr. 45, 20146 Hamburg, Germany
| | - Andreas Kornowski
- Institute of Physical Chemistry, University of Hamburg, Bundesstr. 45, 20146 Hamburg, Germany
| | - Alexander Eychmüller
- Institute of Physical Chemistry, University of Hamburg, Bundesstr. 45, 20146 Hamburg, Germany
| | - Horst Weller
- Institute of Physical Chemistry, University of Hamburg, Bundesstr. 45, 20146 Hamburg, Germany
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680
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Talapin DV, Rogach AL, Shevchenko EV, Kornowski A, Haase M, Weller H. Dynamic distribution of growth rates within the ensembles of colloidal II-VI and III-V semiconductor nanocrystals as a factor governing their photoluminescence efficiency. J Am Chem Soc 2002; 124:5782-90. [PMID: 12010053 DOI: 10.1021/ja0123599] [Citation(s) in RCA: 440] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The distribution of properties within ensembles of colloidally grown II-VI and III-V semiconductor nanocrystals was studied. A drastic difference in the photoluminescence efficiencies of size-selected fractions was observed for both organometallically prepared CdSe and InAs colloids and for CdTe nanocrystals synthesized in aqueous medium, indicating a general character of the phenomenon observed. The difference in the photoluminescence efficiencies is attributed to different averaged surface disorder of the nanocrystals originating from the Ostwald ripening growth mechanism when larger particles in the ensemble grow at the expense of dissolving smaller particles. At any stage of growth, only a fraction of particles within the ensemble of growing colloidal nanocrystals has the most perfect surface and, thus, shows the most efficient photoluminescence. This is explained by a theoretical model describing the evolution of an ensemble of nanocrystals in a colloidal solution. In an ensemble of growing nanocrystals, the fraction of particles with the highest photoluminescence corresponds to the particle size having nearly zero average growth rate. The small average growth rate leads to the lowest possible degree of surface disorder at any given reaction conditions.
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Affiliation(s)
- Dmitri V Talapin
- Institute of Physical Chemistry, University of Hamburg, 20146 Hamburg, Germany.
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681
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Qu L, Peng X. Control of photoluminescence properties of CdSe nanocrystals in growth. J Am Chem Soc 2002; 124:2049-55. [PMID: 11866620 DOI: 10.1021/ja017002j] [Citation(s) in RCA: 768] [Impact Index Per Article: 34.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The photoluminescence (PL) quantum yield (QY) of CdSe nanocrystals during their growth under a given set of initial conditions increases monotonically to a certain maximum value and then decreases gradually. Such a maximum is denoted as a PL "bright point", which does not always overlap with the minimum point of the PL peak width for the same reaction. The experimental results suggest that the existence of the PL bright point is a general phenomenon during the growth of semiconductor nanocrystals and likely is a signature of an optimal surface structure/reconstruction of the nanocrystals grown under a given set of initial conditions. The position of the bright point, the highest PL QY, the types of the bright points (sharp or flat), the sharpness of the PL peak, etc., were all strongly dependent on the initial Cd:Se ratio of the precursors in the solution. A large excess of the selenium precursor, with 5-10 times more selenium precursor than the amount of the cadmium precursor, was found necessary to achieve a high PL QY value and a narrow emission profile. The existence of the PL bright point and the sensitive temporal variation of the PL QY during the growth of semiconductor nanocrystals can explain the unpredictable nature and poor reproducibility of the PL properties of the as-prepared semiconductor nanocrystals observed previously. Furthermore, the knowledge gained in this study enabled us to reproducibly synthesize highly luminescent CdSe nanocrystals through a relatively simple and safe synthetic scheme. In a traditionally weak emission window for CdSe nanocrystals, the orange-red optical window, the PL QY of the as-prepared CdSe nanocrystals reached as high as 85% at room temperature, and the full width at half-maximum of the corresponding PL peak was as narrow as 23 nm, about 65-80 meV depending on the emitting position. The PL properties of the as-prepared CdSe nanocrystals are stable upon aging for at least several months. These as-prepared nanocrystals represent a series of best emitters that are highly efficient, highly pure in emission color, stable, and continuously tunable by simply varying the size of the nanocrystals.
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Affiliation(s)
- Lianhua Qu
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas 72701, USA
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682
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Radovanovic PV, Gamelin DR. Electronic absorption spectroscopy of cobalt ions in diluted magnetic semiconductor quantum dots: demonstration of an isocrystalline core/shell synthetic method. J Am Chem Soc 2001; 123:12207-14. [PMID: 11734020 DOI: 10.1021/ja0115215] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This paper reports the application of ligand-field electronic absorption spectroscopy to probe Co(2+) dopant ions in diluted magnetic semiconductor quantum dots. It is found that standard inverted micelle coprecipitation methods for preparing Co(2+)-doped CdS (Co(2+):CdS) quantum dots yield dopant ions predominantly bound to the nanocrystal surfaces. These Co(2+):CdS nanocrystals are unstable with respect to solvation of surface-bound Co(2+), and time-dependent absorption measurements allow identification of two transient surface-bound intermediates involving solvent-cobalt coordination. Comparison with Co(2+):ZnS quantum dots prepared by the same methods, which show nearly isotropic dopant distribution, indicates that the large mismatch between the ionic radii of Co(2+) (0.74 A) and Cd(2+) (0.97 A) is responsible for exclusion of Co(2+) ions during CdS nanocrystal growth. An isocrystalline core/shell preparative method is developed that allows synthesis of internally doped Co(2+):CdS quantum dots through encapsulation of surface-bound ions beneath additional layers of CdS.
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Affiliation(s)
- P V Radovanovic
- Department of Chemistry, Box 351700, University of Washington, Seattle, WA 98195-1700, USA
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683
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Talapin DV, Rogach AL, Haase M, Weller H. Evolution of an Ensemble of Nanoparticles in a Colloidal Solution: Theoretical Study. J Phys Chem B 2001. [DOI: 10.1021/jp012229m] [Citation(s) in RCA: 415] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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