Monodisperse colloidal CdSe nanocrystals (NCs) with different sizes were synthesized, and the time-resolved photoluminescence (PL) spectra were measured to explore the evolution of surface states during the NC’s growth. The PL quantum yield, fluorescence lifetime, and the surface-related emission had the identical size dependence. The role of the nonradiative/radiative surface states in the PL carrier dynamics was discussed.

Colloidal CdSe nanocrystals (NCs) were successively overcoated with CdS shells, and the X-ray diffraction and Raman measurements of the yielded CdSe/CdS core/shell NCs revealed that stress in the CdSe core was dramatically increased with the growth of the CdS shell but was released when the shell became thicker. The CdSe lattice contraction, photoluminescence (PL) quantum yield, and PL average lifetime exhibit similar dependences on the shell thickness. The PL lifetime undulation with temperature is indicative of the spatial distribution of trap states.

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