Hostname: page-component-7c8c6479df-24hb2 Total loading time: 0 Render date: 2024-03-28T10:07:16.676Z Has data issue: false hasContentIssue false

Photoluminescence Properties and Zeta Potential of Water-Dispersible CdTe Nanocrystals

Published online by Cambridge University Press:  01 February 2011

Masanori Ando
Affiliation:
Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Kansai Center, 1–8–31 Midorigaoka, Ikeda, Osaka 563–8577, JAPAN
Chunliang Li
Affiliation:
Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Kansai Center, 1–8–31 Midorigaoka, Ikeda, Osaka 563–8577, JAPAN
Norio Murase
Affiliation:
Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Kansai Center, 1–8–31 Midorigaoka, Ikeda, Osaka 563–8577, JAPAN
Get access

Abstract

The photoluminescent (PL) properties and zeta potential of green-emitting CdTe nanocrystals (diameter: 3 nm) capped with a stabilizing surfactant, thioglycolic acid (TGA), have been investigated as a function of pH of the aqueous solution. The green PL intensity reached the maximum at pH5.1 and was somewhat lower in the pH range of 6–10, which was similar to the previously reported result. However, when the pH was at and below 4, the green PL intensity decreased drastically. The relative ratio of the dissociation form of the carboxyl group of TGA showed a large diminution at and below pH5 accompanied by a significant decrease of the absolute value of zeta potential. Since the absolute value of zeta potential reflects the stability of nanocrystals, the results obtained shows that the TGA-capped CdTe nanocrystals are stable only in basic to neutral regions and that the agglomeration of the nanocrystals in acidic range reflects the transition from the dissociated (charged) form to the non-dissociated (non-charged) form of a carboxyl group in TGA. Encapsulation of nanocrystals in glass is a promising way to further improve the long-term photostability of nanocrystals. Therefore, we chose an alkoxide having an amino group for a matrix for the encapsulation. The amino group has a good affinity to TGA as well as promotes the sol-gel reaction. As the result, the CdTe nanocrystals have been dispersed finely in the glass matrix without a deterioration of PL intensity.

Type
Research Article
Copyright
Copyright © Materials Research Society 2004

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Dabbousi, B. O., Viejo, J. R.-, Mikulec, F. V., Heine, J. R., Mattoussi, H., Ober, R., Jensen, K. F. and Bawendi, M. G., J. Phys. Chem. B 101, 9463 (1997).Google Scholar
2. Gao, M., Kirstein, S., Möhwald, H., Rogach, A. L., Kornowski, A., Eychmüller, A. and Weller, H., J. Phys. Chem. B 102, 8360 (1998).Google Scholar
3. Rogach, A. L., Katsikas, L., Kornowski, A., Su, D., Eychmüller, A. and Weller, H., Ber. Bunsen-Ges. Phys. Chem. 100, 1772 (1996).Google Scholar
4. Klimov, V. I., Mikhailovsky, A. A., Xu, S., Malko, A., Hollingsworth, J. A., Leatherdale, C. A., Eisler, H.-J. and Bawendi, M. G., Science 290, 314 (2000).Google Scholar
5. Gaponik, N. P., Talapin, D. V., Rogoch, A. L. and Eychmüller, A., J. Mater. Chem. 10, 2163 (2000).Google Scholar
6. Bruchez, M. J., Moronne, M., Gin, P., Weiss, S. and Alivisatos, A. P., Science 281, 2013 (1998).Google Scholar
7. Murray, C. B., Norris, D. J. and Bawendi, M. G., J. Am. Chem. Soc. 115, 8706 (1993).Google Scholar
8. Rajh, T., Micic, O. I. and Nozik, A. J., J. Phys. Chem. 97, 11999 (1993).Google Scholar
9. Selvan, S. T., Bullen, C., Ashokkumar, M. and Mulvaney, P., Adv. Mater. 13, 985 (2001).Google Scholar
10. Li, C. L., Ando, M. and Murase, N., Phys. Status Solidi C (4), 1250 (2003).Google Scholar
11. Brinker, C. J. and Scherer, G. W., Sol-Gel Science (Academic Press, San Diego, 1990).Google Scholar