Fast exciton relaxation and multiple exciton ...
Document type :
Autre communication scientifique (congrès sans actes - poster - séminaire...): Communication dans un congrès avec actes
Title :
Fast exciton relaxation and multiple exciton generation (MEG) in semiconductor nanocrystals : the role of defects
Author(s) :
Delerue, Christophe [Auteur]
Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 [IEMN]
Allan, Guy [Auteur]
Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 [IEMN]
Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 [IEMN]
Allan, Guy [Auteur]
Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 [IEMN]
Conference title :
American Physical Society March Meeting, 2009 APS March Meeting, Focus Session : Nanomaterials for Energy Applications I
City :
Pittsburgh, PA
Country :
Etats-Unis d'Amérique
Start date of the conference :
2009-03-16
HAL domain(s) :
Sciences de l'ingénieur [physics]
English abstract : [en]
Recent works have concluded that a single high-energy photon could generate multiple excitons in semiconductor nanocrystals but these results are debated and are not well understood theoretically. More generally, the physics ...
Show more >Recent works have concluded that a single high-energy photon could generate multiple excitons in semiconductor nanocrystals but these results are debated and are not well understood theoretically. More generally, the physics of the relaxation of excitations in semiconductor nanocrystals receives growing interest. We show that surface defects must play an important role in these processes. We calculate the rate for the relaxation of hot carriers by impact ionization and we show that the presence of surface defects leads to an increase of the relaxation rate at lower excitation energy. We present simulations of the carrier multiplication in Si nanocrystals and we discuss the results of recent experiments in light of these results.Show less >
Show more >Recent works have concluded that a single high-energy photon could generate multiple excitons in semiconductor nanocrystals but these results are debated and are not well understood theoretically. More generally, the physics of the relaxation of excitations in semiconductor nanocrystals receives growing interest. We show that surface defects must play an important role in these processes. We calculate the rate for the relaxation of hot carriers by impact ionization and we show that the presence of surface defects leads to an increase of the relaxation rate at lower excitation energy. We present simulations of the carrier multiplication in Si nanocrystals and we discuss the results of recent experiments in light of these results.Show less >
Language :
Anglais
Peer reviewed article :
Oui
Audience :
Non spécifiée
Popular science :
Non
Source :