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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Dual Cocatalysts Loaded Type I CdS/ZnS Core/Shell Nanocrystals as Effective and Stable Photocatalysts for H2 Evolution
TL;DR: In this paper, a combined method to promote the photocatalytic activity as well as the stability of CdS/ZnS nanocrystals for photocatalysis H2 evolution was reported.
Journal ArticleDOI
Silica-coated CdTe quantum dots functionalized with thiols for bioconjugation to IgG proteins.
Abraham Wolcott,Daniele Gerion,Micah P. Visconte,Jia Sun,Adam M. Schwartzberg,Shaowei Chen,Jin Z. Zhang +6 more
TL;DR: A simple aqueous synthesis of silica-capped, highly fluorescent CdTe quantum dots has been developed, which are potentially useful for a number of applications in biolabeling and imaging.
Journal ArticleDOI
Origin of the Substitution Mechanism for the Binding of Organic Ligands on the Surface of CsPbBr3 Perovskite Nanocubes.
Vikash Kumar Ravi,Pralay K. Santra,Niharika Joshi,Jeetender Chugh,Sachin Kumar Singh,Håkan Rensmo,Prasenjit Ghosh,Angshuman Nag +7 more
TL;DR: The authors' experimental results confirm that oleylammonium ions act as capping ligands by substituting Cs+ ions from the surface of CsPbBr3 NCs, and DFT calculations shows that the substitution mechanism does not require much energy for surface reconstruction and stabilizes the nanocrystal by the formation of three hydrogen bonds.
Patent
Quantum dots of Group IV semiconductor materials
TL;DR: The quantum dot as discussed by the authors is a core including a semiconductor material Y selected from the group consisting of Si and Ge and also comprises a shell surrounding the core, which is substantially defect free such that the quantum dot exhibits photoluminescence with a quantum efficiency that is greater than 10 percent.
Journal ArticleDOI
Crystal structure control of zinc-blende CdSe/CdS core/shell nanocrystals: synthesis and structure-dependent optical properties.
TL;DR: Although the wurtzite counterparts grown under the same conditions showed optical properties similar to those reported in the literature, zinc-blende CdSe/CdS core/shell nanocrystals demonstrated surprisingly different optical properties, with ensemble single-exponential photoluminescence decay, significant decrease of photolumscence peak width by the shell growth, and comparatively high photolUMinescence quantum yields.
References
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Journal ArticleDOI
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.