- Title
- Optical properties of water-soluble L-cysteine-capped alloyed CdSeS quantum dot passivated with ZnSeTe and ZnSeTe/ZnS shells
- Creator
- Adegoke, Oluwasesan, Nyokong, Tebello, Forbes, Patricia B C
- Subject
- To be catalogued
- Date
- 2015
- Type
- text
- Type
- article
- Identifier
- http://hdl.handle.net/10962/193609
- Identifier
- vital:45352
- Identifier
- xlink:href="https://doi.org/10.1016/j.optmat.2015.05.024"
- Description
- Alloyed quantum dots (QDs) passivated with shell materials have valuable optical characteristics suitable for a wide array of applications. In this work, alloyed ternary CdSeS QDs passivated with ZnSeTe and ZnSeTe/ZnS shells have been synthesized via a hot-injection method and a ligand exchange reaction employing L-cysteine as a thiol ligand has been used to obtain these water-soluble nanocrystals for the first time. The photoluminescence (PL) quantum yield (QY) of alloyed L-cysteine-capped CdSeS was 71.2% but decreased significantly to 5.2% upon passivation with a ZnSeTe shell. The red shift in PL emission of the CdSeS/ZnSeTe QDs was attributed to be strain-induced whilst a lattice-induced process likely created defect states in the core/shell interface hence contributing to the decline in the PL QY. Nonetheless, the fluorescence stability of CdSeS/ZnSeTe QDs in aqueous solution was unperturbed. Further passivation with a ZnS shell (CdSeS/ZnSeTe/ZnS) improved the PL QY to a value of 58.7% and thus indicates that the defect state in the QDs core/shell/shell structure was reduced. PL lifetime exciton measurements indicated that the rates of decay of the QDs influenced their photophysical properties.
- Format
- computer, online resource, application/pdf, 1 online resource (7 pages), pdf
- Publisher
- Elsevier
- Language
- English
- Relation
- Optical Materials, Adegoke, O., Nyokong, T. and Forbes, P.B., 2015. Optical properties of water-soluble L-cysteine-capped alloyed CdSeS quantum dot passivated with ZnSeTe and ZnSeTe/ZnS shells. Optical Materials, 46, pp.548-554, Optical Materials volume 46 p. 548 2015 1873-1252
- Rights
- Publisher
- Rights
- Use of this resource is governed by the terms and conditions of the Elsevier Terms and Conditions Statement (https://www.elsevier.com/legal/elsevier-website-terms-and-conditions)
- Rights
- Open Access
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Collections
RU DST/NRF SARChI for Medicinal Chemistry and Nanotechnology
Nyokong, Tebello (Distinguished Professor)
RU Department of Chemistry
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