Dynamics within the exciton fine structure of colloidal CdSe quantum dots

Vanessa Margaret Huxter, Vitalij Kovalevskij, Gregory D. Scholes

Research output: Contribution to journalArticle

37 Citations (Scopus)

Abstract

Evidence for an interaction between the quantum dot exciton fine structure states F = ±1 is obtained by measuring the dynamics of transitions among those states, exciton spin relaxation or flipping. An ultrafast transient grating experiment based on a crossed-linear polarization grating is reported. By using the quantum dot selection rules for absorption of circularly polarized light, it is demonstrated that it is possible to detect transitions between nominally degenerate fine structure states, even in a rotationally isotropic system. The results for colloidal CdSe quantum dots reveal a strong size dependence for the exciton spin relaxation rate from one bright exciton state (F = ±1) to the other in CdSe colloidal quantum dots at 293 K, on a time scale ranging from femtoseconds to picoseconds, depending on the quantum dot size. The results are consistent with an interaction between those states attributed to a long-range contribution to the electron-hole exchange interaction.

Original languageEnglish (US)
Pages (from-to)20060-20063
Number of pages4
JournalJournal of Physical Chemistry B
Volume109
Issue number43
DOIs
StatePublished - Nov 3 2005
Externally publishedYes

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Excitons
Semiconductor quantum dots
fine structure
quantum dots
excitons
gratings
Exchange interactions
interactions
Light polarization
Electron transitions
linear polarization
polarized light
LDS 751
Polarization
Electrons
Experiments

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

Cite this

Dynamics within the exciton fine structure of colloidal CdSe quantum dots. / Huxter, Vanessa Margaret; Kovalevskij, Vitalij; Scholes, Gregory D.

In: Journal of Physical Chemistry B, Vol. 109, No. 43, 03.11.2005, p. 20060-20063.

Research output: Contribution to journalArticle

Huxter, Vanessa Margaret ; Kovalevskij, Vitalij ; Scholes, Gregory D. / Dynamics within the exciton fine structure of colloidal CdSe quantum dots. In: Journal of Physical Chemistry B. 2005 ; Vol. 109, No. 43. pp. 20060-20063.
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