Size and shape dependent level structure in CdSe quantum rods

Abstract

Optical spectroscopy and Scanning Tunneling Microscopy are used to study the size and shape dependence of the electronic states in CdSe quantum rods. The quantum rods were grown using colloidal chemistry synthesis methods, with good control over size and size distribution. Samples having average rod dimensions ranging from 10 to 60 nm in length and 3.5 to 7 nm in diameter, with aspect ratios varying between 3 to 12, were investigated. Both optical (at 10 K) and tunneling (at 4.2 K, on single rods) spectra show that the level structure depends primarily on the rod diameter and not on length. With increasing diameter, the band gap and the excited state level spacings shifted to the red. The level structure is assigned using a multi-band effective-mass model, showing relatively good agreement with experiment. We shall also discuss the effect of single electron charging on the tunneling spectra, possibly reflecting the quantum rod level degeneracy.

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References

  1. 1.

    A. P. Alivisatos, Science 271, 933 (1996).

    CAS  Article  Google Scholar 

  2. 2.

    O. Millo, D. Katz, Y. W. Cao, and U. Banin, Phys. Rev. Lett. 86, 5751 (2001).

    CAS  Article  Google Scholar 

  3. 3.

    V. Klimov, A. Mikhailovsky, S Xu, A Malko, J.A. Hollingsworth, C.A. Leatherdale, H.J. Eisler and M.G. Bawendi, Science 290, 314 (2000).

    CAS  Article  Google Scholar 

  4. 4.

    M. Kazes, D. Y. Lewis, Y. Ebenstein, T. Mokari, and U. Banin, Adv. Mater. 14, 317 (2002).

    CAS  Article  Google Scholar 

  5. 5.

    N. Tessler, V. Medvedev, M. Kazes, S. H. Kan, and U. Banin, Science 295, 1506 (2002).

    Article  Google Scholar 

  6. 6.

    M. Bruchez, M. Moronne, P. Gin, S. Weiss and A.P. Alivisatos, Science 281, 2013 (1998).

    CAS  Article  Google Scholar 

  7. 7.

    X.G. Peng, L. Manna, W.D. Yang, J. Wickham, E. Scher, A. Kadavanich and A.P. Alivisatos, Nature (London) 404, 59 (2000).

    CAS  Article  Google Scholar 

  8. 8.

    J. T. Hu, L.S. Li, W.D. Yang, L. Manna, L.W. Wang and A.P. Alivisatos, Science 291, 2060 (2001).

    Article  Google Scholar 

  9. 9.

    U. Banin, Y. W. Cao, D. Katz, and O. Millo, Nature (London) 400, 542 (1999).

    CAS  Article  Google Scholar 

  10. 10.

    D. J. Norris and M.G. Bawendi, Phys. Rev. B 53, 16338 (1996).

    CAS  Article  Google Scholar 

  11. 11.

    U. Banin, C.J. Lee, A.A. Guzelian, A.V. Kadavanich, A.P. Alivisatos, W. Jaskolski, G.W. Bryant, A.l. Efros and M. Rosen, J. Chem. Phys. 109, 2306 (1998).

    CAS  Article  Google Scholar 

  12. 12.

    E. P. A. M. Bakkers and D. Vanmaekelbergh, Phys. Rev. B 62, R7743 (2000).

    CAS  Article  Google Scholar 

  13. 13.

    E. P. A. M. Bakkers, Z. Hens, A. Zunger, A. Franceschetti, L.P. Kouwenhoven, L. Gurevich and D. Vanmaekelbergh, Nano Lett. 1, 551 (2001).

    CAS  Article  Google Scholar 

  14. 14.

    D. Katz, O. Millo, S. H. Kan, and U. Banin, Appl. Phys. Lett. 79, 117 (2001).

    CAS  Article  Google Scholar 

  15. 15.

    A. Franceschetti and A. Zunger, Phys. Rev. B 62, 2614 (2000).

    CAS  Article  Google Scholar 

  16. 16.

    Y. M. Niquet, C. Delerue, G. Allan and M. Lannoo, Phys. Rev. B 65, 165334 (2002).

    Article  Google Scholar 

  17. 17.

    A. I. Ekimov, F. Hache, M.C. Schanneklein, D. Ricard, C. Flytzanis, I.A. Kudryavtsev, T.V. Yazeva, A.V. Rodina and A.L. Efros, J. Opt. Soc. Am. B 10, 100 (1993).

    CAS  Article  Google Scholar 

  18. 18.

    X. Z. Li and J. B. Xia, Phys. Rev. B 66, 115316 (2002).

    Article  Google Scholar 

  19. 19.

    J. T. Hu, J. Phys. Chem. 106, 2447 (2002).

    CAS  Article  Google Scholar 

  20. 20.

    L. Manna, E. C. Scher, and A.P. Alivisatos, J. Am. Chem. Soc. 122, 12700 (2000).

    CAS  Article  Google Scholar 

  21. 21.

    Z. A. Peng and X. Peng, J. Am. Chem. Soc. 123, 1389 (2001).

    CAS  Article  Google Scholar 

  22. 22.

    M. Tews, and D. Pfannkuche, Phys. Rev. B 65, 073307 (2002).

    Article  Google Scholar 

  23. 23.

    L. S. Li, J. T. Hu, W. D. Yang, and A. P. Alivisatos, Nano Lett. 1, 349 (2001).

    CAS  Article  Google Scholar 

  24. 24.

    P. C. Sercel and K. J. Vahala, Phys. Rev. B 42, 3690 (1990).

    CAS  Article  Google Scholar 

  25. 25.

    D. Katz, T. Wizansky, O. Millo, E. Rothenberg, T. Mokari, and U. Banin, Phys. Rev. Lett. 89, 86801 (2002).

    Article  Google Scholar 

  26. 26.

    L. E. Brus, J. Chem. Phys. 9, 4403 (1984).

    Article  Google Scholar 

  27. 27.

    W. U. Huynh, J. J. Dittmer, and A. P. Alivisatos, Science 295, 2425 (2002).

    CAS  Article  Google Scholar 

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Acknowledgments

This work was supported in part by grants from the Bi-National Science Foundation, the DIP (Deutsche Israel Program) and the Israel Science Foundation.

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Correspondence to Eli Rothenberg.

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Rothenberg, E., Mokari, T., Banin, U. et al. Size and shape dependent level structure in CdSe quantum rods. MRS Online Proceedings Library 737, 171 (2002). https://doi.org/10.1557/PROC-737-E17.1

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