Appearance of polar optical modes in raman scattering in semiconductor nanocrystals

  • A. Yu. Boikov
  • S. V. KarpovEmail author
  • S. V. Mikushev


The Raman spectra of nine samples of glasses with different content of CdSe semiconductor nanocrystals of different dimensions obtained by annealing samples are studied. It is established that, in the spectra of nanocrystals of all samples, there appears a line of the fundamental polar vibration whose frequency is close to that of the longitudinal optical mode of the CdSe bulk crystal. In this case, the asymmetry of this line essentially depends on the sample, the semiconductor concentration, and the local excitation place. To analyze the obtained results, a factor analysis method is used to separate linearly independent components from the data set. It is established that three or four contributions with frequencies near 180, 190, 208, and, probably, 210 cm−1 can be singled out in the contour of the line under consideration. A comparison of the obtained results with the conclusions made by using microscopic models demonstrates a significant difference between the experimental data and the results obtained by using mechanical and dielectrical continuum models. It is possible that the real picture of quantum dot vibrations is more complicated and can be described better within the microscopic model. Moreover, for a CdS nanocrystal, the experimental spectra agree satisfactorily with results of calculation of vibrations, in which 3–4 bands with a frequency difference of 10-15 cm−1 exist in the region of the LO mode for crystals with dimensions of 5 × 5 × 5 unit cells (1000 atoms).


Raman Spectrum Surface Investigation Neutron Technique Raman Line Fundamental Vibration 
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  1. 1.
    A. I. Ekimov and A. A. Onushchenko, Fiz. Tekh. Poluprovodn. 16 (7), 1215 (1982) [Semiconductors 16, 775 (1982)].Google Scholar
  2. 2.
    Al. L. Efros and A. A. Efros, Fiz. Tekh. Poluprovodn. 16 (7), 1209 (1982) [Semiconductors 16, 772 (1982)].Google Scholar
  3. 3.
    A. I. Ekimov, F. Hache, and M. C. Shanne-Klein, J. Opt. Soc. Am. B 10, 100 (1993).Google Scholar
  4. 4.
    P. Lefebvre, T. Richard, J. Allégre, et al., Phys. Rev. B 53, 15440 (1996).Google Scholar
  5. 5.
    D. J. Norris and M. J. Bavendi, J. Chem. Phys. 103, 5260 (1995).Google Scholar
  6. 6.
    D. J. Norris and M. G. Bawendi, Phys. Rev. B 53, 16 338 (1996).Google Scholar
  7. 7.
    E. Roca, C. Trallero-Giner, and M. Cardona, Phys. Rev. B 49 (13), 704 (1994).Google Scholar
  8. 8.
    E. Duval, Phys. Rev. B 46, 5795 (1992).Google Scholar
  9. 9.
    E. P. Denisov, S. V. Karpov, and E. V. Kolobkova, Fiz. Tverd. Tela 41 (7), 1306 (1999) [Phys. Solid State 41, 1194 (1999)].Google Scholar
  10. 10.
    B. Champagnon, B. Andrianasolo, and A. Ramos, J. Appl. Phys. 73 (6), 2775 (1993).Google Scholar
  11. 11.
    V. S. Gorelik, A. V. Igo, and S. N. Minkov, Zh. Eksp. Teor. Fiz. 109 (6), 2141 (1996) [JETP 82, 1154 (1996)].Google Scholar
  12. 12.
    S. V. Karpov, G. K. Muzafarova, and M. A. Yastrebova, Fiz. Tverd. Tela 43 (6), 1126 (2001) [Phys. Solid State 43, 1169 (2001)].Google Scholar
  13. 13.
    I. H. Campbell and P. M. Faucet, Solid State Commun. 58, 739 (1986).Google Scholar
  14. 14.
    M. C. Klein, F. Hache, and D. Ricard, Phys. Rev. 42 (17), 11123 (1990).Google Scholar
  15. 15.
    H. Richter, Z. P. Wang, and L. Ley, Solid State Commun. 39, 625 (1981).Google Scholar
  16. 16.
    I. H. Campbell and P. M. Fauchet, Solid State Commun. 58, 739 (1986).Google Scholar
  17. 17.
    R. Purlys and J. Jakimavicius, Sol. Phys. Collet (USA) 25 (3), 40 (1985).Google Scholar
  18. 18.
    M. Ferrari, B. Champagnon, and M. Borland, J. Non- Cryst. Solids 151, 95 (1992).Google Scholar
  19. 19.
    I. H. Campbell and P. M. Fauchet, Solid State Commun. 58 (10), 739 (1986).Google Scholar
  20. 20.
    H. Richter, Z. P. Wang, and L. Ley, Solid State Commun. 39, 625 (1981).Google Scholar
  21. 21.
    E. Duval, A. Boukenter, and B. Champagnon, Phys. Rev. Lett. 56, 2052 (1986).Google Scholar
  22. 22.
    A. Tamura, K. Higeta, and T. Ichinokawa, J. Phys. C: Solid State Phys. 15, 4975 (1982).Google Scholar
  23. 23.
    F. Comas, C. Trallero-Giner, and S. Nelson, Phys. Rev. B 65, 073 303 (2001).Google Scholar
  24. 24.
    W. Ledermann, Proc. R. Soc. London, Ser. A: Mathem. Phys. Sci. 182, 362 (1944).CrossRefGoogle Scholar
  25. 25.
    S. Karpov, I. Kozakina, and M. Smirnov, in Proc. of Nanoparticles, Nanostructures, Nanocomposites-NNN-2004, Topical Meeting of the European Society, 5–7 July 2004, Saint-Petersburg, Russia (, St. Petersburg, 2004), p. 28.Google Scholar
  26. 26.
    M. V. Volkenshtein, M. A. Eljashevich, and B. I. Stepanov, Molecular Optics (Fizmatlit, Moscow, 1951) [in Russian].Google Scholar
  27. 27.
    M. Kardona, The Base of Semiconductor Physics (Fizmatlit, Moscow, 2002) [in Russian].Google Scholar
  28. 28.
    K. Esbensen, Multidimension Data Analysis: Selected Sections, Ed. by O. E. Rodionova (Altaiskii Gos. Univ., Barnaul, 2003) [in Russian].Google Scholar

Copyright information

© Pleiades Publishing, Ltd. 2008

Authors and Affiliations

  • A. Yu. Boikov
    • 1
  • S. V. Karpov
    • 1
    Email author
  • S. V. Mikushev
    • 1
  1. 1.Fock Research Institute of PhysicsSt. Petersburg State UniversitySt. PetersburgRussia

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