@article {1160,
	title = {Observation of optical gain in solutions of CdS quantum dots at room temperature in the blue region},
	journal = {Applied Physics Letters},
	volume = {88},
	number = {26},
	year = {2006},
	note = {Darugar, Q Qian, W El-Sayed, MA},
	month = {Jun},
	abstract = {The optical gain dynamics has been studied for two CdS quantum dot samples dispersed in toluene at room temperature. This was carried out by using femtosecond transient absorption technique with an excitation at 400 nm and gain measurement was studied at the fluorescence maxima (440 and 460 nm). The optical gain lifetime was found to be as long as 20 ps under pump fluence as low as 0.77 mJ/cm(2). The low threshold is the result of long lifetime of electrons and holes and narrow emission bandwidth. These results suggest that CdS quantum dots in solution are excellent gain media for optically pumped high power blue lasers.},
	isbn = {0003-6951},
	doi = {10.1063/1.2217138},
	author = {Darugar, Q. and Qian, Wei and El-Sayed, Mostafa A}
}
@article {1159,
	title = {Size-dependent ultrafast electronic energy relaxation and enhanced fluorescence of copper nanoparticles},
	journal = {Journal of Physical Chemistry B},
	volume = {110},
	number = {1},
	year = {2006},
	note = {Darugar, Q Qian, W El-Sayed, MA Pileni, MP},
	month = {Jan},
	pages = {143-149},
	abstract = {The energy relaxation of the electrons in the conduction band of 12 and 30 nm diameter copper nanoparticles in colloidal solution was investigated using femtosecond time-resolved transient spectroscopy. Experimental results show that the hot electron energy relaxation is faster in 12 nm copper nanoparticles (0.37 ps) than that in 30 nm copper nanoparticles (0.51 ps), which is explained by the size-dependent electron-surface phonon coupling. Additional mechanisms involving trapping or energy transfer processes to the denser surface states (imperfection) in the smaller nanoparticles are needed to explain the relaxation rate in the 12 nm nanoparticles. The observed fluorescence quantum yield from these nanoparticles is found to be enhanced by roughly 5 orders of magnitude for the 30 nm nanoparticles and 4 orders of magnitude for the 12 nm nanoparticles (relative to bulk copper metal). The increase in the fluorescence quantum yield is attributed to the electromagnetic enhancement of the radiative recombination of the electrons in the s-p conduction band below the Fermi level with the holes in the d bands due to the strong surface plasmon oscillation in these nanoparticles.},
	isbn = {1520-6106},
	doi = {10.1021/jp0545445},
	author = {Darugar, Q. and Qian, Wei and El-Sayed, Mostafa A and Pileni, Marie-Paule}
}
@article {1189,
	title = {Why is the thermalization of excited electrons in semiconductor nanoparticles so rapid? Studies on CdSe nanoparticles},
	journal = {Chemical Physics Letters},
	volume = {373},
	number = {3-4},
	year = {2003},
	note = {Darugar, Q Landes, C Link, S Schill, A El-Sayed, MA},
	month = {May},
	pages = {284-291},
	abstract = {Quantum confinement of electronic motion in semiconductor nanoparticles leads to quantization of its band continua of the bulk. The relaxation between the resulting quantized levels by electron phonon coupling was expected, but not found, to be slow due to the small phonon frequencies (phonon bottleneck). Studying the electronic relaxation from the band gap and a higher excited state in CdSe dots and rods under different perturbations suggest the importance of coupling the excited electron to the surface. The surface species act as an efficient heat bath or as electron trapping sites in the linear or nonlinear (Auger) relaxation processes. (C) 2003 Elsevier Science B.V. All rights reserved.},
	isbn = {0009-2614},
	doi = {10.1016/s0009-2614(03)00213-6},
	author = {Darugar, Q. and Landes, Christy F. and Link, Stephan and Schill, A. W. and El-Sayed, Mostafa A}
}
