Quelques illustrations du rôle de la surface dans des nanoparticules de ZnO

Abstract : This work presents an investigation of phonons and excitons in Zinc Oxide nanoparticles.
We show that two kinds of surface related effects can be illustrated via phonons. First we focus on size reduction. Linear elasticity theory fails to reproduce acoustic mode frequencies for nanoparticles less than 2.5 nm. Experiments confirm this point. Second, we show that ligands, organic molecules bonded ont the nanoparticles surface, are preferentially localized on the nanoparticles lateral surface. In addition, ligands slightly stretch ZnO crystal lattice.
Concerning excitonic properties, we show the UV emission is dominated by surface bound exciton. Moreover, the very fast recombination process suggests the recombination dynamics of the exciton is mainly dominated by non radiative processes.
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Contributor : Pierre-Marie Chassaing <>
Submitted on : Thursday, July 23, 2009 - 8:54:48 AM
Last modification on : Monday, April 29, 2019 - 4:39:33 PM
Long-term archiving on : Tuesday, June 15, 2010 - 9:12:09 PM

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  • HAL Id : tel-00406581, version 1

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Pierre-Marie Chassaing. Quelques illustrations du rôle de la surface dans des nanoparticules de ZnO. Physique [physics]. Université Paul Sabatier - Toulouse III, 2009. Français. ⟨tel-00406581⟩

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