Title :

Long-range transport in an assembly of ZnO quantum dots : the effects of quantum confinement, Coulomb repulsion and structural disorder

Author(s) :

Roest, Aarnoud L. [Auteur]
Utrecht University [Utrecht]
Germeau, Alexander [Auteur]
Utrecht University [Utrecht]
Kelly, John J. [Auteur]
Utrecht University [Utrecht]
Vanmaekelbergh, Daniel [Auteur]
Utrecht University [Utrecht]
Allan, Guy [Auteur]
Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 [IEMN]
Meulenkamp, Eric A. [Auteur]
Utrecht University [Utrecht]

Journal title :

ChemPhysChem

Pages :

959-966

Publisher :

Wiley-VCH Verlag

Publication date :

2003

ISSN :

1439-4235

HAL domain(s) :

Sciences de l'ingénieur [physics]

English abstract : [en]

We have studied the storage and long-range transport of electrons in a porous assembly of weakly coupled ZnO quantum dots permeated with an aqueous and a propylene carbonate electrolyte solution. The number of electrons ...
Show more >We have studied the storage and long-range transport of electrons in a porous assembly of weakly coupled ZnO quantum dots permeated with an aqueous and a propylene carbonate electrolyte solution. The number of electrons per ZnO quantum dot is controlled by the electrochemical potential of the assembly; the charge of the electrons is compensated by ions present in the pores. We show with optical and electrical measurements that the injected electrons occupy the S, P, and D type conduction electron levels of the quantum dots; electron storage in surface states is not important. With this method of three-dimensional charge compensation, up to ten electrons per quantum-dot can be stored if the assembly is permeated with an aqueous electrolyte. The screening of the electron charge is less effective in the case of an assembly permeated with a propylene carbonate electrolyte solution. Long-range electron transport is studied with a transistor set-up. In the case of ZnO assemblies permeated with an aqueous electrolyte, two quantum regimes are observed corresponding to multiple tunnelling between the S orbitals (at a low occupation) and P orbitals (at a higher occupation). In a ZnO quantum-dot assembly permeated with a propylene carbonate electrolyte solution, there is a strong overlap between these two regimes.Show less >

Language :

Anglais

Peer reviewed article :

Oui

Audience :

Non spécifiée

Popular science :

Non

Collections :

• Institut d'Électronique, de Microélectronique et de Nanotechnologie (IEMN) - UMR 8520

Source :

Harvested from HAL