Hostname: page-component-7c8c6479df-ws8qp Total loading time: 0 Render date: 2024-03-29T00:42:30.862Z Has data issue: false hasContentIssue false

Ultrafast Electron Dynamics in Ge Quantum Dots

Published online by Cambridge University Press:  10 February 2011

A. Stella
Affiliation:
Istituto Nazionale per la Fisica della Materia – Dipartimento di Fisica “A. Volta”, Università di Pavia, Via Bassi 6. 1-27100 Pavia, Italy
P. Tognini
Affiliation:
Istituto Nazionale per la Fisica della Materia – Dipartimento di Fisica “A. Volta”, Università di Pavia, Via Bassi 6. 1-27100 Pavia, Italy
S. De Silvestri
Affiliation:
Istituto Nazionale per la Fisica della Materia – Dipartimento di Fisica Politecnico di Milano, Centro di Elettronica Quantistica e Strumentazione Elettronica – CNR, Milano, Italy
M. Nisoli
Affiliation:
Istituto Nazionale per la Fisica della Materia – Dipartimento di Fisica Politecnico di Milano, Centro di Elettronica Quantistica e Strumentazione Elettronica – CNR, Milano, Italy
S. Stagira
Affiliation:
Istituto Nazionale per la Fisica della Materia – Dipartimento di Fisica Politecnico di Milano, Centro di Elettronica Quantistica e Strumentazione Elettronica – CNR, Milano, Italy
P. Cheyssac
Affiliation:
Laboratoire de Physique de la Matière Condensèe, URA 190, Université de Nice-Sophia Antipolis, 06108 Nice Cedex, France
R. Kofman
Affiliation:
Laboratoire de Physique de la Matière Condensèe, URA 190, Université de Nice-Sophia Antipolis, 06108 Nice Cedex, France
Get access

Abstract

An analysis of the ultrafast response of Ge quantum dots, with average radii of 4 nm and 16 nm, is reported here. Pump and probe experiments allowed investigation of the wavelength region between 450 and 750 nrm, characterized by the absorption peaks due to the E, and E11 interband transitions. Two different time regimes have been identified: a first one (τ ≤ 1 ps) associated with pump-induced conduction band filling in the τ-L direction in the Brillouin zone; a second one (τ up to 100 ps) associated with band gap renormalization caused by the carrier interaction in the conduction band. Quantum confinement effects show up in terms of sizedependent blueshift of the E11 spectral feature.

Type
Research Article
Copyright
Copyright © Materials Research Society 2000

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Kreibig, U. and Vollmer, M., Optical Properties of Metal Clusters (Springer-Verlag, Berlin, 1995); A. Stella, M. Nisoli, S. De Silvestri. O. Svelto, G. Lanzani, P. Cheyssac, R. Kofman, Phys. Rev. B 53, 15497 (1996).10.1007/978-3-662-09109-8Google Scholar
2. Woggon, U., Optical Properties of Semiconductor Quantum Dots (Springer-Verlag, Berlin Heidelberg, 1997), and references therein.Google Scholar
3. Mittleman, D.M., Schoenlein, R. W., Shiang, J. J. and Colvin, V. L., Alivisatos, A. P., and Shank, C. V., Phys. Rev. B 49, 14435 (1994), and references therein.10.1103/PhysRevB.49.14435Google Scholar
4. Banin, U., Cerullo, G., Guzelian, A. A., Bardeen, C. J., Alivisatos, A. P., and Shank, C. V., Phys. Rev. B 55, 7059 (1997).10.1103/PhysRevB.55.7059Google Scholar
5. Zhou, X.Q., Driel, H. M. van, and Mak, G., Phys. Rev. B 50, 5226 (1994); M. Woerner, W. Frey, M. T. Portella, C. Ludwig, T. Elsaesser, and W. Kaiser, Phys. Rev. B 49, 17007 (1994).10.1103/PhysRevB.50.5226Google Scholar
6. Zollner, S., Myers, K.D., Jensen, K.G., Dolan, J.M., Bailey, D.W., Stanton, C.J., Sol. St. Comm. 104, 51 (1997).10.1016/S0038-1098(97)00068-9Google Scholar
7. Rappen, T., Peter, U., Wegener, M., and Schafer, W., Phys. Rev. B 48, 4879 (1993); K. Tanaka, H. Ohtake, and T. Suemoto, Phys. Rev. Lett. 71, 1935 (1993).10.1103/PhysRevB.48.4879Google Scholar
8. Dowd, A., Elliman, R. G., Samoc, M. and Luther-Davies, B., Appl. Phys. Lett. 74, 239 (1999).10.1063/1.123267Google Scholar
9. Cohen, M.L. and Chelikowsky, J.R., Electronic Structure and Optical Properties of Semiconductors (Springer-Verlag, Berlin, 1988).10.1007/978-3-642-97080-1Google Scholar
10. Tognini, P., Andreani, L.C., Geddo, M., Stella, A., Cheyssac, P., Kofman, R. and Migliori, A., Phys. Rev. B 53, 6992 (1996); P. Tognini, L.C. Andreani, M. Geddo, A. Stella, P. Cheyssac and R. Kofman, I1 Nuovo Cimento D 18, 865 (1996).10.1103/PhysRevB.53.6992Google Scholar
11. Othonos, A., Driel, H.M. van, Young, J.F. and Kelly, P.J., Phys. Rev. B 43, 6682 (1991).10.1103/PhysRevB.43.6682Google Scholar
12. Shah, J., Ultrafast Spectroscopy of Semiconductors and Semiconductor Nanostructures (Springer-Verlag, Berlin, 1996).10.1007/978-3-662-03299-2Google Scholar
13. Haight, R., Baeumler, M., Phys. Rev. B 46, 1543 (1992).10.1103/PhysRevB.46.1543Google Scholar
14. Aspnes, D.E. and Studna, A.A., Phys. Rev. B 27, 985 (1983).10.1103/PhysRevB.27.985Google Scholar
15. Zimmermann, R., Phys. Stat. Sol. (b) 146, 371 (1988).10.1002/pssb.2221460140Google Scholar
16. Choo, H.R., Hu, X.F., Downer, M.C. and Kesan, V.P., Appl. Phys. Lett. 63, 1507 (1993).10.1063/1.109671Google Scholar
17. Genzel, L. and Martin, T.P., Surf. Sci. 34, 33 (1973).10.1016/0039-6028(73)90185-4Google Scholar