@article {852,
	title = {The pump power dependence of the femtosecond relaxation of CdSe nanoparticles observed in the spectral range from visible to infrared},
	journal = {The Journal of chemical physics},
	volume = {116},
	year = {2002},
	pages = {3828},
	abstract = {The pump power dependence of the relaxation dynamics of CdSe nanoparticles (NPs) was studied with femtosecond pump probe spectroscopy at observation wavelengths of the first exciton transition at 560 nm, the near infrared (NIR) absorption at 2 μm, and the transient mid-infrared (IR) absorption at 4.5 μm. Excitation with less than one photon per particle leads to bleaching of the excitonic transitions, and the bleach intensity is initially linear to the pump power. At higher pump power the bleach intensity levels off, when complete saturation of the excitonic transition is reached. At the same time, increasing pump power causes an acceleration of the bleach decay, which is due to additional Auger processes when multiple excitons are formed in the NPs. In addition, the pump power effect was investigated for the NIR and IR regions, at 2 and 4.5 μm wavelength, respectively. Whereas the IR transients are very similar to the ones observed for the bleach, the NIR transients behave completely different. No pump power dependence was found for the transients at 2 μm when pumped in a power range from 0.5 to 5 μJ per pulse. The results show that the fs transients in the visible (bleach) and IR (absorption) regions are due to electron relaxation in the conduction band and the NIR transients are due to the relaxation of the hole. Furthermore, it suggests that in the investigated CdSe NPs, Auger processes act much more efficiently on the electrons than for the holes. },
	doi = {10.1063/1.1446851},
	url = {http://link.aip.org/link/doi/10.1063/1.1446851},
	author = {Burda, Clemens and Link, Stephan and Mohamed, MB and El-Sayed, Mostafa A}
}
@article {1215,
	title = {Photoluminescence of CdSe nanoparticles in the presence of a hole acceptor: n-butylamine},
	journal = {Journal of Physical Chemistry B},
	volume = {105},
	number = {15},
	year = {2001},
	note = {Landes, C Burda, C Braun, M El-Sayed, MA},
	month = {Apr},
	pages = {2981-2986},
	abstract = {Addition of butylamine to a solution of colloidal CdSe nanoparticles (NPs) caused a decrease in fluorescence intensity, with no effect on the picosecond bleach recovery of the exciton formation or on the luminescence dynamics. The relative fluorescence quantum yield was found to decrease with increasing butylamine concentration and to level off at high concentrations, but the fluorescence lifetimes were not influenced. The nonlinear concentration dependence of the fluorescence quantum yield did not follow the Stern-Volmer equation. This is in agreement with the observation that the CdSe luminescence lifetime was not affected by the addition of butylamine. A mechanism is proposed in which the emission observed in CdSe is assumed to result from the combination of surface-trapped electrons and holes. n-Butylamine occupies hole sites, thus blocking the recombination process, which results in decreasing the density of luminescent centers. These results will be discussed in terms of the nature of the binding sites of the amine on the nanoparticle surface.},
	isbn = {1089-5647},
	doi = {10.1021/jp0041050},
	author = {Landes, Christy F. and Burda, Clemens and Braun, Markus and El-Sayed, Mostafa A}
}
