Journal ArticleDOI
(CdSe)ZnS Core-Shell Quantum Dots - Synthesis and Characterization of a Size Series of Highly Luminescent Nanocrystallites
B. O. Dabbousi,Javier Rodríguez-Viejo,F. V. Mikulec,Jason Heine,Hedi Mattoussi,R. Ober,K. F. Jensen,‡,§ and,Moungi G. Bawendi +7 more
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TLDR
In this paper, a synthesis of highly luminescent (CdSe)ZnS composite quantum dots with CdSe cores ranging in diameter from 23 to 55 A was reported.Abstract:
We report a synthesis of highly luminescent (CdSe)ZnS composite quantum dots with CdSe cores ranging in diameter from 23 to 55 A. The narrow photoluminescence (fwhm ≤ 40 nm) from these composite dots spans most of the visible spectrum from blue through red with quantum yields of 30−50% at room temperature. We characterize these materials using a range of optical and structural techniques. Optical absorption and photoluminescence spectroscopies probe the effect of ZnS passivation on the electronic structure of the dots. We use a combination of wavelength dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, small and wide angle X-ray scattering, and transmission electron microscopy to analyze the composite dots and determine their chemical composition, average size, size distribution, shape, and internal structure. Using a simple effective mass theory, we model the energy shift for the first excited state for (CdSe)ZnS and (CdSe)CdS dots with varying shell thickness. Finally, we characterize the...read more
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Core−Shell Quantum Dots of Lattice-Matched ZnCdSe2 Shells on InP Cores: Experiment and Theory
TL;DR: In this article, lattice-matched ZnCdSe2 concentric epilayer shells up to 50 A in thickness have been grown on InP core quantum dots (QDs) and the quality of epitaxially grown shells was monitored by absorption and emission spectra and transmission electron microscopy (TEM).
Journal ArticleDOI
One-step hydrothermal preparation strategy for nanostructured WO3/Bi2WO6 heterojunction with high visible light photocatalytic activity
TL;DR: In this paper, the WO 3 /Bi 2 WO 6 hierarchical heterojunction was successfully prepared by a facile hydrothermal preparation strategy, and the as-prepared sample consists of WO-3 nanoparticles growing on the primary Bi 2WO 6 nanoplatelets.
Journal ArticleDOI
Interactions between Redox Complexes and Semiconductor Quantum Dots Coupled via a Peptide Bridge
Igor L. Medintz,Thomas Pons,Scott A. Trammell,Amy F. Grimes,Doug S. English,Juan B. Blanco-Canosa,Philip E. Dawson,Hedi Mattoussi +7 more
TL;DR: It is found that quenching of the QD emission is highly dependent on the relative position of the oxidation levels of QDs and metal complex used; it also traces the number of metal complexes brought in close proximity of the nanocrystal surface.
Journal ArticleDOI
“Flash” Synthesis of CdSe/CdS Core–Shell Quantum Dots
Marco Cirillo,Tangi Aubert,Raquel Gomes,Rik Van Deun,Philippe Emplit,Amelie Biermann,Holger Lange,Christian Thomsen,Edouard Brainis,Zeger Hens +9 more
TL;DR: In this paper, the authors report on the flash synthesis of CdSe/CdS core-shell quantum dots (QDs) based on a seeded growth approach and using an excess of a carboxylic acid, leading to an isotropic and epitaxial growth of a CdS shell on a wurtzite core.
Journal ArticleDOI
Nanoparticle-based environmental sensors
Libing Wang,Wei Ma,Wei Ma,Liguang Xu,Liguang Xu,Wei Chen,Wei Chen,Yingyue Zhu,Yingyue Zhu,Chuanlai Xu,Nicholas A. Kotov +10 more
TL;DR: Nanoparticle (NP)-based environmental sensors have the potential to detect toxins, heavy metals, and organic pollutants in air, water, and soil, and are expected to play an increasingly important role in environmental monitoring as mentioned in this paper.
References
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Synthesis and characterization of nearly monodisperse CdE (E = sulfur, selenium, tellurium) semiconductor nanocrystallites
TL;DR: In this paper, a simple route to the production of high-quality CdE (E=S, Se, Te) semiconductor nanocrystallites is presented, based on pyrolysis of organometallic reagents by injection into a hot coordinating solvent.