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Synthesis and Characterization of CdSe/CdS Core-Shell and CdSe/CdS Composites

Published online by Cambridge University Press:  21 February 2011

M. Azad Malika ,
Paul O'Brien  and
N. Revaprasaduac
M. Azad Malika
Affiliation:
Department of Chemistry, Imperial College of Science, Technology and Medicine, Exhibition Road, London, W7 2AZ, UK
Paul O'Brien
Affiliation:
Manchester Materials Science Centre and Department of Chemistry, Manchester University, Oxford Rd, Manchester M13 9PL. E-mail:p.obrien@ic.ac.uk
N. Revaprasaduac
Affiliation:
Department of Chemistry, Imperial College of Science, Technology and Medicine, Exhibition Road, London, W7 2AZ, UK Department of Chemistry, University of Zululand, Private Bag X1001, Kwadlangezwa, 886., South Africa
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Abstract

Highly mono-dispersed CdSe/CdS core-shell and CdSe/CdS composites have been prepared by a novel route involving thermolysis in TOPO using Cd(Se2CNMe(nHex))2 and Cd(S2CNMe(nHex))2. The absorption band edge (652 nm, 1.90 eV) of the CdSe-CdS core-shell structure is red shifted (22 nm, 0.0 17 eV) as compared to the CdSe nanoparticles (630 nm, 1.96 eV) whereas the absorption spectrum of the CdSe-CdS composites shows the absorption band edge at (584 nm, 2.12 eV), blue shifted (46 nm, 0.037 eV) as expected. Photoluminescence (PL, λex = 400 nm) of both the core-shell (622 nm) and the composites (588 nm) show values close to band edge emission. A sharper emission maximum with a considerable increase of intensity is observed for core-shell structure as compared to that of CdSe whereas the composite showed a broader emission maximum. The TEM images of the CdSe/CdS core-shell nanoparticles show crystalline, spherical particles with the average size of 53 Å (±7 %), a increase of 8 Å than the average size of CdSe (45 Å) nanoparticles, with a narrow size distribution. The High Resolution Transmission Electron Microscopy (HRTEM) showed lattice spacing intermediate between those for CdSe and CdS as is observed by Selected Area Electron Diffraction (SAED) and X-ray patterns (hexagonal phase). As expected no interface can be observed by HRTEM between CdSe core and CdS shell. The TEM image of the CdSe-CdS composites show particles with an average size of 48.7 Å (±10%).

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 581: Symposium F – Nanophase & Nanocomposite Materials II , 1999 , 291
Copyright
Copyright © Materials Research Society 2000

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References

REFERENCES

1. Henglein, A., Chem. Rev., 89, 1861 (1989).Google Scholar
2. Weller, H., Adv. Mater., 5, 88 (1993).Google Scholar
3. Steigerwald, M. L. and Brus, L. E., Acc. Chem. Rev., 23, 183 (1990).Google Scholar
4. Noglik, H. and Pietro, W.J., Chem. Mater.,6, 1593(1994).Google Scholar
5. Katari, J. E., Colvin, V. L. and Alivisatos, A. P., J. Phys. Chem., 98, 4109 (1994).Google Scholar
6. Trindade, T., Zhang, X., O'Brien, P., Chem. Mater., 9, 523 (1997).Google Scholar
7. Danek, M., Jensen, K. F., Murray, C. B., and Bawendi, M. G., Chem. Mater., 8, 173 (1996).Google Scholar
8. Hines, M. A. and Guyot-Sionnest, P., J. Phys. Chem., 100, 468 (1996).Google Scholar
9. Kortan, A. R., Hull, R., Opila, R. L., Bawendi, M. G., Steigerwald, M. L., Carrol, P. J. and Brus, L. E., J. Am. Chem. Soc., 112, 1327 (1990).Google Scholar
10. Peng, X., Schlamp, M. C., Kadavanich, A. V. and Alivisatos, A. P., J. Am. Chem. Soc., 119, 7019 (1997).Google Scholar
11. Tian, Y., Newton, T., Kotov, N. A., Guldi, D. M., and Fendler, J. H., J. Phys. Chem. 100, 8927 (1996).Google Scholar
12. Banin, U., Bruchez, M., Alivisatos, A. P., Ha, T., Weiss, S. and Chemla, D. S., J. Chem. Phys., 110, 1195 (1999).Google Scholar
13. Ludolph, B., Malik, M. A., Revaprasadu, N. and O'Brien, P., J. Chem. Soc. Chem,. Commun., 1849 (1998).Google Scholar