Excess Charge in Small Semiconductor Particles

  • C. Luangdilok
  • D. Lawless
  • D. Meisel
Part of the NATO ASI Series book series (ASHT, volume 12)

Abstract

We address the question of the effect of excess charge on the spectroscopy of small semiconductor particles. A variety of reducing species was used to inject charge into small CdS particles. A blue-shift or broadening of the spectrum is often observed at the low energy edge of the absorption. The effect of the excess charges on the absorption spectra of the particles is independent of the source of the electrons or the pH of the solution. The spectral shifts are essentially independent of the loading of electrons into the particle. Time resolved conductivity measurements show that no protons are released to the bulk of the solution upon injection of electrons from H atoms below the point of zero charge. We infer that a dipole is created across the particle in that case.

To demonstrate the effect of excess charge at the particle surface we added electrons to capping molecules attached to the surface. The surface of the particles was modified to include various electron acceptors of known redox potentials. Injection of electrons into these acceptors at the surface generates the radical anion of the corresponding molecule and its absorption spectrum could easily be monitored. However, the same spectral effects on the absorption edge of the particles could be observed in this case as in the direct injection of the electrons into the particle. It is concluded that the effects result from the electric field associated with the excess charge.

Keywords

Difference Spectrum Excess Charge Free Thiol Mercaptopropionic Acid Electric Field Effect 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    Albery, J., Brown, G. T., Darwent, J.R., Saievar-Iranizad, E. (1986) J. Chem. Soc. Faraday Trans. 181, 1999.Google Scholar
  2. 2.
    Henglein, A., Kumar, A., Janata, E., Weller, H. (1986) Chem. Phys. Lett. 132, 133.CrossRefGoogle Scholar
  3. 3.
    Henglein, A. (1989) Chan. Rev. 89, 1861.Google Scholar
  4. 4.
    Hilinski, E. F., Luccas, P.A., Wang, Y. (1988) J. Chem. Phys. 89, 3435.CrossRefGoogle Scholar
  5. 5.
    Liu, C., Bard, A. J. (1989) J. Chem. Phys. 93, 3232.CrossRefGoogle Scholar
  6. 6.
    Liu, C., Bard, A. J. (1989) J. Chem. Phys. 93, 7047.CrossRefGoogle Scholar
  7. 7.
    Kamat, P. V., Dimitrijevic, N. M., Nozik, A. J. (1989) J. Phys. Chem. 93, 2873.CrossRefGoogle Scholar
  8. 8.
    Colvin, V. L., Alivisatos, A. P. (1992) J. Chem. Phys. 97, 730.CrossRefGoogle Scholar
  9. 9.
    Nosaka, Y., Yamaguchi, K., Miyama, H., Hayashi, H. (1988) Chan Lett. 605.Google Scholar
  10. 10.
    Nosaka, Y., Ohta, N., Fukuyama, T., Fujii, N. (1993) J. Coil. Interface Sci. 155, 23.CrossRefGoogle Scholar
  11. 11.
    Hayes, D., Micic, O. I., Nenadovic, M. T., Swayambunathan, V., Meisel, D. (1989) J. Phys. Chem. 93, 4603.CrossRefGoogle Scholar
  12. 12.
    Swayambunathan, V., Hayes, D., Schmidt, K.H., Liao, Y. X., Meisel, D. (1990) J. Am. Chem. Soc. 112, 3831.CrossRefGoogle Scholar
  13. 13.
    Asmus, K. (1990) Sulfur Centered Reactive Intermediates in Chem. and Bio. Plenum Press, New York and London, Vol. 197.Google Scholar
  14. 14.
    Borgarello, E., Pelizzetti, E., Mulac, W.A., Meisel, D. (1985) J. Chem. Soc., Faraday Trans. 1 81 143.Google Scholar
  15. Matheson, M. S., Lee, P. C., Meisel, D., Pelizzetti, E. (1983) J. Phys. Chem. 87, 394.CrossRefGoogle Scholar
  16. 15.
    Meisel, D., Neta, P. (1975) J. Am. Chem. Soc. 97, 5198.CrossRefGoogle Scholar

Copyright information

© Kluwer Academic Publishers 1996

Authors and Affiliations

  • C. Luangdilok
    • 1
  • D. Lawless
    • 1
  • D. Meisel
    • 1
  1. 1.Chemistry DivisionArgonne National LaboratoryArgonneUSA

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