@article {1146,
	title = {Ultrafast electronic relaxation and charge-carrier localization in CdS/CdSe/CdS quantum-dot quantum-well heterostructures},
	journal = {Nano Letters},
	volume = {6},
	number = {9},
	year = {2006},
	note = {Schill, Alexander W. Gaddis, Christopher S. Qian, Wei El-Sayed, Mostafa A. Cai, Ye Milam, Valeria T. Sandhage, Kenneth},
	month = {Sep},
	pages = {1940-1949},
	abstract = {The relaxation and localization times of excited electrons in CdS/CdSe/CdS colloidal quantum wells were measured using subpicosecond spectroscopy. HRTEM analysis and steady-state PL demonstrate a narrow size distribution of 5-6 nm epitaxial crystallites. By monitoring the rise time of the stimulated emission as a function of pump intensity, the relaxation times of the electron from the CdS core into the CdSe well are determined and assigned. Two-component rise times in the stimulated emission are attributed to intraband relaxation of carriers generated directly within the CdSe well ( fast component) and charge transfer of core-localized carriers across the CdS/CdSe interface ( slow component). This is the first reported observation of simultaneous photon absorption in the core and well of a quantum-dot heterostructure. With increasing pump intensity, the charge-transfer channel between the CdS core CdSe well contributes less to the stimulated emission signal because of filling and saturation of the CdSe well state, making the interfacial charge-transfer component less efficient. The interfacial charge-transfer time of the excited electron was determined from the slow component of the stimulated emission build-up time and is found to have a value of 1.2 ps.},
	isbn = {1530-6984},
	doi = {10.1021/nl061054v},
	author = {Schill, A. W. and Gaddis, C. S. and Qian, Wei and El-Sayed, Mostafa A and Cai, Y. and Milam, V. T. and Sandhage, K.}
}
