Abstract
Femtosecond nonlinear transmission techniques are applied to study mechanisms for optical nonlinearities and ultrafast carrier dynamics in CdS nanocrystals (NC's). The obtained data indicate the change in a dominant hole relaxation channel at high pump levels where nonlinear recombination effects start to play a significant role. This is manifested as a distinct difference in nonlinear-optical responses measured at low and high pump intensities in quasiequilibrium at long times after excitation. The analysis of the wavelength and time dependence of the nonlinear transmission over a wide pump-intensity range shows clearly that this difference is due to an Auger-process-assisted trapping of holes at surface/interface-related states. This trapping leads to efficient charge separation and the generation of a dc electric field that modifies the nonlinear optical response in NC's at high pump intensities.
| Original language | English |
|---|---|
| Pages (from-to) | 13173-13179 |
| Number of pages | 7 |
| Journal | Physical Review B - Condensed Matter and Materials Physics |
| Volume | 55 |
| Issue number | 19 |
| Publication status | Published - May 15 1997 |
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ASJC Scopus subject areas
- Condensed Matter Physics
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Auger-process-induced charge separation in semiconductor nanocrystals. / Klimov, Victor I; McBranch, Duncan W.
In: Physical Review B - Condensed Matter and Materials Physics, Vol. 55, No. 19, 15.05.1997, p. 13173-13179.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Auger-process-induced charge separation in semiconductor nanocrystals
AU - Klimov, Victor I
AU - McBranch, Duncan W.
PY - 1997/5/15
Y1 - 1997/5/15
N2 - Femtosecond nonlinear transmission techniques are applied to study mechanisms for optical nonlinearities and ultrafast carrier dynamics in CdS nanocrystals (NC's). The obtained data indicate the change in a dominant hole relaxation channel at high pump levels where nonlinear recombination effects start to play a significant role. This is manifested as a distinct difference in nonlinear-optical responses measured at low and high pump intensities in quasiequilibrium at long times after excitation. The analysis of the wavelength and time dependence of the nonlinear transmission over a wide pump-intensity range shows clearly that this difference is due to an Auger-process-assisted trapping of holes at surface/interface-related states. This trapping leads to efficient charge separation and the generation of a dc electric field that modifies the nonlinear optical response in NC's at high pump intensities.
AB - Femtosecond nonlinear transmission techniques are applied to study mechanisms for optical nonlinearities and ultrafast carrier dynamics in CdS nanocrystals (NC's). The obtained data indicate the change in a dominant hole relaxation channel at high pump levels where nonlinear recombination effects start to play a significant role. This is manifested as a distinct difference in nonlinear-optical responses measured at low and high pump intensities in quasiequilibrium at long times after excitation. The analysis of the wavelength and time dependence of the nonlinear transmission over a wide pump-intensity range shows clearly that this difference is due to an Auger-process-assisted trapping of holes at surface/interface-related states. This trapping leads to efficient charge separation and the generation of a dc electric field that modifies the nonlinear optical response in NC's at high pump intensities.
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UR - http://www.scopus.com/inward/citedby.url?scp=0001476267&partnerID=8YFLogxK
M3 - Article
VL - 55
SP - 13173
EP - 13179
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 1098-0121
IS - 19
ER -