The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics

, Volume 6, Issue 2, pp 255–267

Tight-binding studies of surface effects on electronic structure of CdSe nanocrystals: the role of organic ligands, surface reconstruction, and inorganic capping shells


  • S. Pokrant
    • Department of Chemistry, University of California at Berkeley, Berkeley, CA 94720, USA
  • K.B. Whaley
    • Department of Chemistry, University of California at Berkeley, Berkeley, CA 94720, USA

DOI: 10.1007/s100530050307

Cite this article as:
Pokrant, S. & Whaley, K. Eur. Phys. J. D (1999) 6: 255. doi:10.1007/s100530050307


We utilize a tight-binding model to study the effects of surface structure on electronic properties of CdSe clusters. The model takes into account experimental information about structure and shape of the nanocrystals, as well as the nature and distribution of capping ligands. The effects of both organic capping ligands and inorganic capping shells on the densities of states (DOS) and on the single-particle absorption spectra of the clusters are calculated for various cluster shapes and sizes, and are compared to results for clusters with truncated surfaces. For organic capping ligands, the effect of ligand hybridization is investigated and a simple model of surface reconstruction is developed. Both ligand hybridization and surface reconstruction are seen to have a major influence on the band edge electronic and optical properties. Inorganic capping shells give rise to differential localization of valence and conduction band edge states, with the hole primarily confined to the core region and the electron more evenly distributed over both core and shell.

PACS. 71.24.+q Electronic structure of clusters and nanoparticles 71.55.Gs II-VI semiconductors 73.20.Dx Electron states in low-dimensional structures (superlattices, quantum well structures and multilayers)

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© EDP Sciences, Springer-Verlag 1999