Preparation and optical properties of capped-CdSe nanocrystals

Capped-CdSe nanocrystals were synthesized by colloidal method and almost mo nodisperse nanocrystals were obtained by size selective precipitation. Pers istent spectral hole-burning (PSHB) effects of the CdSe nanocrystals suspen ded in an organic solvent glass matrix were examined at liquid-Me temperatu re. Prominent spectral changes were not observed for the irradiation of the burning light of 15 mW/cm(2) at the peak position of the exciton absorptio n band. In single nanoparticle spectroscopy of dilute CdSe samples. the flu orescence emitted by small aggregates of the nanocrystals were observed and vanished continuously by the irradiation of strong laser beam. Detection o f the single dot itself is not realized, mainly due to the background noise . (C) 2000 Elsevier Science B.V. All rights reserved.