Mechanisms for intraband energy relaxation in semiconductor quantum dots: The role of electron-hole interactions

Victor I Klimov, A. A. Mikhailovsky, D. W. McBranch, C. A. Leatherdale, M. G. Bawendi

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206 Citations (Scopus)

Abstract

To evaluate the role of nonphonon energy relaxation mechanisms in quantum dots and in particular the role of electron-hole (e-h) interactions, we have studied femtosecond carrier dynamics in CdSe colloidal nanoparticles in which the e-h separation (coupling) is controlled using different types of surface Iigands. In dots capped with hole accepting molecules, the e-h coupling is strongly reduced after the hole is transferred to a capping group. By re-exciting an electron within the conduction band at different stages of hole transfer and monitoring its relaxation back into the ground state, we observe a more than tenfold increase in the electron relaxation time (from 250 fs to 3 ps) after the completion of the hole transfer to the capping molecule. This strongly indicates that electron relaxation in quantum dots is dominated not by phonon emission but by the e-h energy transfer.

Original languageEnglish
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume61
Issue number20
Publication statusPublished - May 15 2000

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Semiconductor quantum dots
quantum dots
Electrons
interactions
energy
Molecules
electrons
Conduction bands
Relaxation time
Energy transfer
Ground state
molecules
conduction bands
Nanoparticles
relaxation time
energy transfer
Monitoring
nanoparticles
ground state

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

Mechanisms for intraband energy relaxation in semiconductor quantum dots : The role of electron-hole interactions. / Klimov, Victor I; Mikhailovsky, A. A.; McBranch, D. W.; Leatherdale, C. A.; Bawendi, M. G.

In: Physical Review B - Condensed Matter and Materials Physics, Vol. 61, No. 20, 15.05.2000.

Research output: Contribution to journalArticle

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