Photoenhancement of luminescence in colloidal CdSe quantum dot solutions

Marcus Jones, Jovan Nedeljkovic, Randy J. Ellingson, Arthur J. Nozik, Gary Rumbles

Research output: Contribution to journalArticle

284 Citations (Scopus)

Abstract

Enhancement of the photoluminescence (PL) of colloidal CdSe and (core)shell (CdSe)ZnS quantum dots has been observed when the dots are illuminated above the band-gap energy. The effect occurs in dots suspended in a variety of organic or aqueous environments. During periods of constant illumination, the exciton PL quantum yield was found to reach a value of up to 60 times that of the solution of as-prepared quantum dots and, if illumination continued, subsequently declined slowly because of photooxidation. When returned to the dark, the PL reverted to near its original value. The rate and magnitude of photoenhancement are found to depend on the illumination wavelength, the presence of a ZnS shell, the solvent environment, and the concentration of surfactant molecules. Time-resolved measurements of the fluorescence decay reveal multiexponential kinetics and an average lifetime that lengthens during the illumination period and shortens when quantum dots are returned to darkness. It is postulated that the stabilization of surface trap states, lengthening their average lifetime, could occur by a light-activated rearrangement of surfactant molecules, thus increasing the probability of thermalization back to the lowest emitting exciton state and enhancing the quantum dot PL.

Original languageEnglish
Pages (from-to)11346-11352
Number of pages7
JournalJournal of Physical Chemistry B
Volume107
Issue number41
Publication statusPublished - Oct 16 2003

Fingerprint

Semiconductor quantum dots
Luminescence
Photoluminescence
Lighting
illumination
quantum dots
luminescence
photoluminescence
Surface-Active Agents
Excitons
Surface active agents
surfactants
excitons
darkness
life (durability)
Molecules
Photooxidation
photooxidation
Quantum yield
Time measurement

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

Cite this

Jones, M., Nedeljkovic, J., Ellingson, R. J., Nozik, A. J., & Rumbles, G. (2003). Photoenhancement of luminescence in colloidal CdSe quantum dot solutions. Journal of Physical Chemistry B, 107(41), 11346-11352.

Photoenhancement of luminescence in colloidal CdSe quantum dot solutions. / Jones, Marcus; Nedeljkovic, Jovan; Ellingson, Randy J.; Nozik, Arthur J.; Rumbles, Gary.

In: Journal of Physical Chemistry B, Vol. 107, No. 41, 16.10.2003, p. 11346-11352.

Research output: Contribution to journalArticle

Jones, M, Nedeljkovic, J, Ellingson, RJ, Nozik, AJ & Rumbles, G 2003, 'Photoenhancement of luminescence in colloidal CdSe quantum dot solutions', Journal of Physical Chemistry B, vol. 107, no. 41, pp. 11346-11352.
Jones M, Nedeljkovic J, Ellingson RJ, Nozik AJ, Rumbles G. Photoenhancement of luminescence in colloidal CdSe quantum dot solutions. Journal of Physical Chemistry B. 2003 Oct 16;107(41):11346-11352.
Jones, Marcus ; Nedeljkovic, Jovan ; Ellingson, Randy J. ; Nozik, Arthur J. ; Rumbles, Gary. / Photoenhancement of luminescence in colloidal CdSe quantum dot solutions. In: Journal of Physical Chemistry B. 2003 ; Vol. 107, No. 41. pp. 11346-11352.
@article{d666afab7e1c4632a301a10160059539,
title = "Photoenhancement of luminescence in colloidal CdSe quantum dot solutions",
abstract = "Enhancement of the photoluminescence (PL) of colloidal CdSe and (core)shell (CdSe)ZnS quantum dots has been observed when the dots are illuminated above the band-gap energy. The effect occurs in dots suspended in a variety of organic or aqueous environments. During periods of constant illumination, the exciton PL quantum yield was found to reach a value of up to 60 times that of the solution of as-prepared quantum dots and, if illumination continued, subsequently declined slowly because of photooxidation. When returned to the dark, the PL reverted to near its original value. The rate and magnitude of photoenhancement are found to depend on the illumination wavelength, the presence of a ZnS shell, the solvent environment, and the concentration of surfactant molecules. Time-resolved measurements of the fluorescence decay reveal multiexponential kinetics and an average lifetime that lengthens during the illumination period and shortens when quantum dots are returned to darkness. It is postulated that the stabilization of surface trap states, lengthening their average lifetime, could occur by a light-activated rearrangement of surfactant molecules, thus increasing the probability of thermalization back to the lowest emitting exciton state and enhancing the quantum dot PL.",
author = "Marcus Jones and Jovan Nedeljkovic and Ellingson, {Randy J.} and Nozik, {Arthur J.} and Gary Rumbles",
year = "2003",
month = "10",
day = "16",
language = "English",
volume = "107",
pages = "11346--11352",
journal = "Journal of Physical Chemistry B Materials",
issn = "1520-6106",
publisher = "American Chemical Society",
number = "41",

}

TY - JOUR

T1 - Photoenhancement of luminescence in colloidal CdSe quantum dot solutions

AU - Jones, Marcus

AU - Nedeljkovic, Jovan

AU - Ellingson, Randy J.

AU - Nozik, Arthur J.

AU - Rumbles, Gary

PY - 2003/10/16

Y1 - 2003/10/16

N2 - Enhancement of the photoluminescence (PL) of colloidal CdSe and (core)shell (CdSe)ZnS quantum dots has been observed when the dots are illuminated above the band-gap energy. The effect occurs in dots suspended in a variety of organic or aqueous environments. During periods of constant illumination, the exciton PL quantum yield was found to reach a value of up to 60 times that of the solution of as-prepared quantum dots and, if illumination continued, subsequently declined slowly because of photooxidation. When returned to the dark, the PL reverted to near its original value. The rate and magnitude of photoenhancement are found to depend on the illumination wavelength, the presence of a ZnS shell, the solvent environment, and the concentration of surfactant molecules. Time-resolved measurements of the fluorescence decay reveal multiexponential kinetics and an average lifetime that lengthens during the illumination period and shortens when quantum dots are returned to darkness. It is postulated that the stabilization of surface trap states, lengthening their average lifetime, could occur by a light-activated rearrangement of surfactant molecules, thus increasing the probability of thermalization back to the lowest emitting exciton state and enhancing the quantum dot PL.

AB - Enhancement of the photoluminescence (PL) of colloidal CdSe and (core)shell (CdSe)ZnS quantum dots has been observed when the dots are illuminated above the band-gap energy. The effect occurs in dots suspended in a variety of organic or aqueous environments. During periods of constant illumination, the exciton PL quantum yield was found to reach a value of up to 60 times that of the solution of as-prepared quantum dots and, if illumination continued, subsequently declined slowly because of photooxidation. When returned to the dark, the PL reverted to near its original value. The rate and magnitude of photoenhancement are found to depend on the illumination wavelength, the presence of a ZnS shell, the solvent environment, and the concentration of surfactant molecules. Time-resolved measurements of the fluorescence decay reveal multiexponential kinetics and an average lifetime that lengthens during the illumination period and shortens when quantum dots are returned to darkness. It is postulated that the stabilization of surface trap states, lengthening their average lifetime, could occur by a light-activated rearrangement of surfactant molecules, thus increasing the probability of thermalization back to the lowest emitting exciton state and enhancing the quantum dot PL.

UR - http://www.scopus.com/inward/record.url?scp=0242270654&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0242270654&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0242270654

VL - 107

SP - 11346

EP - 11352

JO - Journal of Physical Chemistry B Materials

JF - Journal of Physical Chemistry B Materials

SN - 1520-6106

IS - 41

ER -