Luminescence and Resonance Raman Spectroscopy of Indirect Excitons in AgBr Nanocrystals


AgBr nanocrystals with radii R ≈ 2.5 to 5 nm comparable with the exciton Bohr radius are produced in inverse micelles. As compared with bulk AgBr, the exciton emission exhibits a substantial blue shift and enhanced intensity due to the spatial confinement. Besides luminescence, first- and second-order resonance Raman scattering is discovered the occurrence of a zero-phonon process clearly revealing mixing of L with Г point states. From time-resolved measurements, exciton lifetimes of the order of 500 μs are found. They are close to the radiative lifetime in the bulk demonstrating that nonradiative processes are negligible in these nanocrystals. In agreement with state mixing, the total decay rate is found proportional to R−2. A small shift of the TO(L) Raman line with excitation photon energy is analyzed in terms of the wavevector dependent interaction of the quantized exciton states with the dispersive phonon.

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  1. [1]

    L. Brus, Appl. Phys. A 53, 465 (1991).

    Article  Google Scholar 

  2. [2]

    T. Itoh, M. Furumiya, T. Ikehara, Y. Iwabuchi, T. Kirihara, and C. Gourdon, in Proc. Taiwan-Jap. Workshop on Solid Opt. Spectr. (World Scientific, Singapore, 1991).

    Google Scholar 

  3. [3]

    C. Flytzanis and J. Hutter, in Contemporary Nonlinear Optics edited by G.P. Agrawal and R.W. Boyd (Academic Press, London, 1992) p. 297.

  4. [4]

    D.J. Lockwood, Solid State Commun. 92, 101 (1994).

    CAS  Article  Google Scholar 

  5. [5]

    K.P. Johansson, G.L. McLendon, and A.P. Marchetti, Chem. Phys. Lett. 179, 321 (1991).

    CAS  Article  Google Scholar 

  6. [6]

    K.P. Johansson, A.P. Marchetti, and G.L. McLendon, J. Phys. Chem. 96, 2873 (1992).

    CAS  Article  Google Scholar 

  7. [7]

    A.P. Marchetti, K.P. Johansson, and G.L. McLendon, Phys. Rev. B 47, 4268 (1993-11).

    CAS  Article  Google Scholar 

  8. [8]

    H. Kanzaki and Y. Tadakuma, Solid State Commun. 80, 33 (1991)

    CAS  Article  Google Scholar 

  9. [9]

    U. Scholle, H. Stolz, and W. von der Osten, Solid State Commun. 86, 657 (1993).

    CAS  Article  Google Scholar 

  10. [10]

    S. Pawlik, U. Scholle, T. Weber, H. Stolz, and W. von der Osten, J. Physique IV, Coll. C5, suppl. J. Physique II, 151 (1993).

    Google Scholar 

  11. [11]

    W. von der Osten, in Topics in Applied Physics, Light Scattering in Solids VI, edited by M. Cardona and W. Güntherodt (Springer, Berlin, 1991), p. 361.

  12. [12]

    Y. Masumoto, T. Kawamura, T. Ohzeki, and S. Urabe, Phys. Rev. B 46, 1827 (1992-1).

    CAS  Article  Google Scholar 

  13. [13]

    Y. Kayanuma, Phys. Rev. B 38, 9797 (1988-1).

    CAS  Article  Google Scholar 

  14. [14]

    S. Pawlik, Diplomarbeit, Universität-GH Paderborn 1993

    Google Scholar 

  15. [15]

    Y. Toyozawa, private communication.

  16. [16]

    L.A. Banyai, Habilitationsschrift, Universität Frankfurt/Main (1991).

    Google Scholar 

  17. [17]

    M. Timme, E. Schreiber, H. Stolz and W. von der Osten, Solid State Commun. 55, 79 (1993).

    CAS  Google Scholar 

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Pawlik, S., Stolz, H. & Von Der Osten, W. Luminescence and Resonance Raman Spectroscopy of Indirect Excitons in AgBr Nanocrystals. MRS Online Proceedings Library 358, 289 (1994).

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