Europhys. Lett.
Volume 65, Number 6, March 2004
Page(s) 809 - 815
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 01 March 2004
Europhys. Lett., 65 (6) , pp. 809-815 (2004)
DOI: 10.1209/epl/i2003-10130-3

Evolution of the density of states on going from a two- to a zero-dimensional semiconductor

Z. Hens1, B. Grandidier2, D. Deresmes2, G. Allan2, C. Delerue2, D. Stiévenard2 and D. Vanmaekelbergh3

1  Physical Chemistry Laboratory, Ghent University Krijgslaan 281-S12, B-9000 Gent, Belgium
2  IEMN (CNRS, UMR 8520), Département ISEN 41 bd Vauban, 59046, Lille Cédex, France
3  Debye Institute, Utrecht University P.O. Box 80000, 3508 TA Utrecht, The Netherlands

(Received 13 October 2003; accepted in final form 22 January 2004)

Lead selenide nanocrystals have been electrodeposited on gold(111) with a high degree of control over their dimensions, giving rise to isolated nanocrystals with different edge-to-height aspect ratio. The electron density of states (DOS) of individual nanocrystals as a function of their aspect ratio is studied in the regime of strong quantum confinement by electron tunnelling spectroscopy. We find a broad transition regime, spanning the two- and zero-dimensional geometry, where the DOS function has a rich and variable structure, featuring steps and peaks. The experimental results are supported by electronic-structure calculations.

73.22.-f - Electronic structure of nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals.
73.63.Hs - Quantum wells.
73.63.Kv - Quantum dots.

© EDP Sciences 2004