Spectroscopy of neutral and charged exciton states in single CdSe/ZnS nanocrystals
نویسندگان
چکیده
We report a low temperature spectroscopic study of the lowest-energy exciton states in single CdSe/ZnS colloidal nanocrystals. In their neutral charge state, the zero-phonon lines of the lowest two levels of the band-edge exciton fine structure are directly observed in the photoluminescence spectrum. The attribution of these lines is confirmed by polarization-resolved studies of the photoluminescence spectrum and decay. We also identified the emission from charged nanocrystals which displays a single zero-phonon line ~17 meV red-shifted with respect to the neutral nanocrystal emission lines. This bright trion state has a lifetime which ranges from 1.5 to 4.5 ns.
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