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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The use of heat transfer fluids in the synthesis of high-quality CdSe quantum dots, core/shell quantum dots, and quantum rods
Subashini Asokan,Karl M. Krueger,Ammar S. Alkhawaldeh,Ammar S. Alkhawaldeh,Alessandra R. Carreon,Zuze Mu,Zuze Mu,Vicki L. Colvin,Nikos V. Mantzaris,Michael S. Wong +9 more
TL;DR: Heat transfer fluids, a class of organic liquids commonly used in chemical process industries to transport heat between unit operations, are identified as alternative solvents for quantum dot synthesis and it is shown that two heat transfer fluids can be used successfully in the synthesis of CdSe quantum dots with uniform particle sizes.
Journal ArticleDOI
Polymer-coated quantum dots
TL;DR: This work reviews the coating methods, including multidentate and amphiphilic polymeric coatings, and graft-to and grafting-from approaches, and highlights the most commonly used polymers and discusses how their chemical structure influences the coating properties.
Journal ArticleDOI
Materialien für den resonanten Fluoreszenzenergietransfer (FRET): jenseits klassischer Donor‐Acceptor‐Kombinationen
TL;DR: The resonante Forster- oder Fluoreszenzenergietransfer (FRET) wird seit uber 50 Jahren als Grundlage spektroskopischer Techniken genutzt.
Journal ArticleDOI
Surface effects on quantum dot-based energy transfer.
Smita Dayal,Clemens Burda +1 more
TL;DR: The energy transfer efficiency does not follow a linear dependence on spectral overlap integrals as predicted by the Förster theory for molecules, and is found to be due to the involvement of QD surface states in the energy transfer process from the photoexcited QDs to the molecular energy acceptor.
Patent
Quantum dots, nanocomposite materials with quantum dots, optical devices with quantum dots, and related fabrication methods
TL;DR: In this article, a quantum dot is described as a core consisting of a semiconductor material Y selected from the group consisting of Si and Ge, and the quantum dot also comprises a shell surrounding the core.
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.