Abstract
We report changes in the photophysical properties of core-shell type CdSe/ZnS quantum dots (QDs) under optical irradiation. QDs either in aqueous solution or immobilized in a silica sol gel matrix have been excited at different wavelengths and fluxes. Illumination of the sample with 140 fs 700 nm Ti:sapphire laser pulses of the peak power of the order of 4 GW/cm(2) caused gradual increase in the luminescence lifetime from an initial value of 3.5 increasing to 4.5 ns and an increase in luminescence intensity by similar to 8%. Using about 16 GW/cm(2) peak power resulted in a shortening of the luminescence lifetime to 3 ns and a decrease in intensity by similar to 75%. Both photobrightening and photodarkening were fully reversible. We discuss the kinetics of photobrightening and photodarkening and investigate the suitability of QDs as luminescence lifetime sensors with tunable parameters.
| Language | English |
|---|---|
| Article number | 021108 |
| Number of pages | 3 |
| Journal | Applied Physics Letters |
| Volume | 98 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 11 Jan 2011 |
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Keywords
- live cells
- in-vivo
- nanoparticles
- anisotropy
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The effect of intensity of excitation on CdSe/ZnS quantum dots : opportunities in luminescence sensing. / Sutter, Jens U.; Birch, David J. S.; Rolinski, Olaf J.
In: Applied Physics Letters, Vol. 98, No. 2, 021108 , 11.01.2011.Research output: Contribution to journal › Article
TY - JOUR
T1 - The effect of intensity of excitation on CdSe/ZnS quantum dots
T2 - Applied Physics Letters
AU - Sutter, Jens U.
AU - Birch, David J. S.
AU - Rolinski, Olaf J.
PY - 2011/1/11
Y1 - 2011/1/11
N2 - We report changes in the photophysical properties of core-shell type CdSe/ZnS quantum dots (QDs) under optical irradiation. QDs either in aqueous solution or immobilized in a silica sol gel matrix have been excited at different wavelengths and fluxes. Illumination of the sample with 140 fs 700 nm Ti:sapphire laser pulses of the peak power of the order of 4 GW/cm(2) caused gradual increase in the luminescence lifetime from an initial value of 3.5 increasing to 4.5 ns and an increase in luminescence intensity by similar to 8%. Using about 16 GW/cm(2) peak power resulted in a shortening of the luminescence lifetime to 3 ns and a decrease in intensity by similar to 75%. Both photobrightening and photodarkening were fully reversible. We discuss the kinetics of photobrightening and photodarkening and investigate the suitability of QDs as luminescence lifetime sensors with tunable parameters.
AB - We report changes in the photophysical properties of core-shell type CdSe/ZnS quantum dots (QDs) under optical irradiation. QDs either in aqueous solution or immobilized in a silica sol gel matrix have been excited at different wavelengths and fluxes. Illumination of the sample with 140 fs 700 nm Ti:sapphire laser pulses of the peak power of the order of 4 GW/cm(2) caused gradual increase in the luminescence lifetime from an initial value of 3.5 increasing to 4.5 ns and an increase in luminescence intensity by similar to 8%. Using about 16 GW/cm(2) peak power resulted in a shortening of the luminescence lifetime to 3 ns and a decrease in intensity by similar to 75%. Both photobrightening and photodarkening were fully reversible. We discuss the kinetics of photobrightening and photodarkening and investigate the suitability of QDs as luminescence lifetime sensors with tunable parameters.
KW - live cells
KW - in-vivo
KW - nanoparticles
KW - anisotropy
UR - http://www.scopus.com/inward/record.url?scp=78751484540&partnerID=8YFLogxK
U2 - 10.1063/1.3534784
DO - 10.1063/1.3534784
M3 - Article
VL - 98
JO - Applied Physics Letters
JF - Applied Physics Letters
SN - 0003-6951
IS - 2
M1 - 021108
ER -