Semiconductors

, 45:474 | Cite as

Percolation and excitonic luminescence in SiO2/ZnO two-phase structures with a high density of quantum dots randomly distributed over a spherical surface

Semiconductor Structures, Low-Dimensional Systems, and Quantum Phenomena

Abstract

The results of studies of structures formed of silica (SiO2) nanospheres and ZnO quantum dots randomly distributed over the nanosphere surface to cover an ∼0.45 fraction of the surface area are given. Because of the large surface energy of the spheres, the quantum dots formed on their surface are shaped as disks, wherein charge carriers are influenced by the quantum-confinement effect despite the large disk radii. The disk height is calculated by the effective mass method. The height is found to be comparable with the diameter of excitons in bulk ZnO. Analysis of the optical spectra shows that, at the above-indicated surface area covered with quantum dots, excitons in the array of quantum dots are above the percolation level. The use of some concepts of the percolation theory and knowledge of the topological arrangement of the samples make it possible to obtain quantitative parameters that describe this phenomenon.

References

  1. 1.
    A. N. Gruzintsev, G. A. Emel’chenko, V. M. Masalov, E. E. Ekimov, K. Bartkhou, and A. Maitre, Fiz. Tekh. Poluprovodn. 43, 209 (2009) [Semiconductors 43, 197 (2009)].Google Scholar
  2. 2.
    G. A. Emel’chenko, A. N. Gruzintsev, M. N. Koval’chuk, V. M. Masalov, E. N. Samarov, E. E. Ekimov, K. Bartkhou, and I. I. Zver’kova, Fiz. Tekh. Poluprovodn. 39, 1375 (2005) [Semiconductors 39, 1328 (2005)].Google Scholar
  3. 3.
    A. N. Gruzintsev, G. A. Emel’chenko, and V. M. Masalov, Fiz. Tekh. Poluprovodn. 43, 1054 (2009) [Semiconductors 43, 1017 (2009)].Google Scholar
  4. 4.
    Yingling Yanga, Hongwei Yana, Zhengping Fua, Beifang Yanga, Linsheng Xiaa, Zhen Wanda, Jian Zuob, Shijun Yub, Shengquan Fub, and Fanqing Li, J. Luminecs. 124, 228 (2007).CrossRefADSGoogle Scholar
  5. 5.
    O. C. Monteiro, A. Catarina, C. Esteves, and T. Trindade, Chem. Mater. 14, 2900 (2002).CrossRefGoogle Scholar
  6. 6.
    Yu-Yun Penga, Tsung-Eong Hsieh, and Chia-Hung Hsu, App. Phys. Lett. 89, 2111 (909) (2006).Google Scholar
  7. 7.
    Y. V. Yermolayeva, Y. N. Savin, and A. V. Tolmachev, Solid State Phenom. 151, 264 (2009).CrossRefGoogle Scholar
  8. 8.
    N. Johner, C. Grimaldi, I. Balberg, and P. Ryser, Phys. Rev. B 77, 174204 (2008).CrossRefADSGoogle Scholar
  9. 9.
    N. V. Bondar and M. S. Brodyn, Physica E 42, 1549 (2010).CrossRefADSGoogle Scholar
  10. 10.
    N. V. Bondar, Low Temp. Phys. 35, 232 (2009).CrossRefADSGoogle Scholar
  11. 11.
    V. A. Fonoberov, K. A. Alim, A. A. Balandin, Faxian Xiu, and Jianlin Liu, Phys. Rev. B 73, 165317 (2006).CrossRefADSGoogle Scholar
  12. 12.
    S. Le. Goff and B. Stebe, Phys. Rev. B 47, 1383 (1993).CrossRefADSGoogle Scholar
  13. 13.
    E. A. Muljarov, E. A. Zhukov, V. S. Dneprovskii, and Y. Masumoto, Phys. Rev. B 62, 7420 (2000).CrossRefADSGoogle Scholar
  14. 14.
    N. V. Bondar’, V. V. Tishchenko, and M. S. Brodin, Fiz. Tekh. Poluprovodn. 34, 588 (2000) [Semiconductors 34, 568 (2000)].Google Scholar
  15. 15.
    J. Quintanilla, Phys. Rev. B 43, 061108 (2001).Google Scholar
  16. 16.
    Ch. D. Lorenza and R. M. Ziff, Physica A 296 1 (2001).CrossRefADSGoogle Scholar
  17. 17.
    S. Torquato, Phys. Rev. E 51, 3170 (1995).CrossRefADSGoogle Scholar
  18. 18.
    D. Scott and Ch. A. Tout, Mon. Not. R. Astron. Soc. 241, 109 (1989).ADSGoogle Scholar
  19. 19.
    F. Rajadell, J. L. Movilla, M. Royo, and J. Planelles, Phys. Rev. B 76, 115312 (2007).CrossRefADSGoogle Scholar

Copyright information

© Pleiades Publishing, Ltd. 2011

Authors and Affiliations

  1. 1.Institute of PhysicsNational Academy of Sciences of UkraineKyivUkraine

Personalised recommendations