Ultrafast dynamics of inter- and intraband transitions in semiconductor nanocrystals: Implications for quantum-dot lasers

Victor I Klimov, Ch J. Schwarz, D. W. McBranch, C. A. Leatherdale, M. G. Bawendi

Research output: Contribution to journalArticle

208 Citations (Scopus)

Abstract

Application of femtosecond transient absorption in the visible and near-IR spectral ranges and time-resolved photoluminescence allows us to separate electron and hole relaxation paths and to map the structure of interband and intraband optical transitions in CdSe and CdS nanocrystals (NC's) with a wide range of surface properties. In contrast to electron relaxation, which is controlled by NC surface passivation, depopulation of hole quantized states is extremely fast (sub-ps-to-ps time scales) in all types samples, independent of NC surface treatment (including NC's overcoated with a ZnS layer). Our results suggest that ultrafast hole dynamics are not due to trapping at localized surface defects such as a vacancy, but rather arise from relaxation into intrinsic NC states or intrinsically unpassivated interface states.

Original languageEnglish
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume60
Issue number4
Publication statusPublished - Jul 15 1999

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Quantum dot lasers
Nanocrystals
nanocrystals
quantum dots
Semiconductor materials
lasers
Optical transitions
Electrons
Interface states
Surface defects
surface defects
surface treatment
optical transition
Passivation
surface properties
passivity
Vacancies
Surface properties
Surface treatment
Photoluminescence

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

Ultrafast dynamics of inter- and intraband transitions in semiconductor nanocrystals : Implications for quantum-dot lasers. / Klimov, Victor I; Schwarz, Ch J.; McBranch, D. W.; Leatherdale, C. A.; Bawendi, M. G.

In: Physical Review B - Condensed Matter and Materials Physics, Vol. 60, No. 4, 15.07.1999.

Research output: Contribution to journalArticle

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