- Title
- Fluorescence properties of alloyed ZnSeS quantum dots overcoated with ZnTe and ZnTe/ZnS shells
- Creator
- Adegoke, Oluwasesan, Mashazi, Philani N, Nyokong, Tebello, Forbes, Patricia B C
- Subject
- To be catalogued
- Date
- 2016
- Type
- text
- Type
- article
- Identifier
- http://hdl.handle.net/10962/240754
- Identifier
- vital:50868
- Identifier
- xlink:href="https://doi.org/10.1016/j.optmat.2016.02.024"
- Description
- Fluorescent alloyed ternary ZnSeS quantum dots (QDs) have been synthesized via the pyrolysis of organometallic precursors. The effects of passivation of ZnTe and ZnTe/ZnS shells on the optical properties of the ternary alloyed ZnSeS core have been studied. A ligand exchange reaction using L-cysteine as a capping ligand was used to obtain water-soluble nanocrystals. The nanocrystals were each characterized by UV/vis absorption and fluorescence spectroscopy, transmission electron microscopy, X-ray diffractometry (XRD) and X-ray photoelectron spectroscopy (XPS). The photoluminescence (PL) quantum yield (QY) of alloyed ZnSeS QDs was 14% and this value increased to 27% when ZnTe was overcoated around the surface but further coating with a ZnS shell decreased the PL QY slightly to 24%. This implies that ZnTe shell suppressed non-radiative recombination exciton states in the alloyed core while further layering with a ZnS shell offered no further improvement in suppressing the defect states. XPS analysis confirmed the presence of the first shell layering but showed a weakened intensity signal of S (2p) and Se (3d) for the ZnSeS/ZnTe/ZnS QDs. Our work demonstrates for the first time that shell passivation of alloyed Zn-based QDs can offer improved optical properties. We hope the optical information presented in this work will be useful in the selection of alloyed Zn-based QDs appropriate for the intended application.
- Format
- computer, online resource, application/pdf, 1 online resource (7 pages), pdf
- Publisher
- Elsevier
- Language
- English
- Relation
- Optical Materials, Adegoke, O., Mashazi, P., Nyokong, T. and Forbes, P.B., 2016. Fluorescence properties of alloyed ZnSeS quantum dots overcoated with ZnTe and ZnTe/ZnS shells. Optical Materials, 54, pp.104-110, Optical Materials volume 54 p. 104 2016 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
- Closed Access
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Mashazi, Philani N (Associate Prof)
RU DST/NRF SARChI for Medicinal Chemistry and Nanotechnology
Nyokong, Tebello (Distinguished Professor)
RU Department of Chemistry
SDG 03. Good Health and Well-Being
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| View Details Download | SOURCE1 | Fluorescence properties of alloyed ZnSeS quantum dots.pdf | 746 KB | Adobe Acrobat PDF | View Details Download |