Virzbickas, K, Rimkute, L, Harvie, AJ orcid.org/0000-0002-7840-6639 et al. (1 more author) (2017) Surfactant-dependent photoluminescence of CdTe/CdS nanocrystals. Journal of Experimental Nanoscience, 12 (1). pp. 94-103. ISSN 1745-8080
Abstract
The photoluminescence of aqueously synthesised core/shell CdTe/CdS quantum dots (QDs) was investigated. Two molar ratios (2.4 and 1.3) of thioglycolic acid (TGA) to Cd2+ were compared to determine the best synthesis conditions for high photoluminescent quantum yield (PLQY) and photostability. A difference in the PLQY of the CdTe/CdS QDs was observed when CdS shells were grown with different TGA/Cd2+ ratios. The difference in the observed PLQY was attributed to the quality of the passivation of the CdTe during the CdS shell growth. At TGA/Cd2+ ratio of 1.3, the CdS shell forms through homogeneous nucleation, which is limited by diffusion of growth material from the solution onto the QDs surface. Due to the lattice mismatch of CdTe and CdS, the core will experience coherence strain resulting in dislocation sites and surface defects between nucleation sites which can result in non-radiative trap states. When the TGA/Cd2+ ratio is 2.0, the CdS shell grows epitaxially, minimising the number of surface trap states. Finally, we observed that the fluorescence intermittency was supressed for CdTe QDs after UV light illumination, attributed to annealing of deep surface trap states by UV light.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2017 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
Keywords: | CdTe/CdS, photoluminescence, TGA, blinking, photostability |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Physics and Astronomy (Leeds) > Molecular & Nanoscale Physics |
Depositing User: | Symplectic Publications |
Date Deposited: | 03 Mar 2017 16:47 |
Last Modified: | 23 Jun 2023 22:25 |
Published Version: | https://doi.org/10.1080/17458080.2016.1273553 |
Status: | Published |
Publisher: | Taylor & Francis |
Identification Number: | 10.1080/17458080.2016.1273553 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:113132 |