Fluorescence Spectroscopy on Single CdS Nanocrystals

Abstract

By use of low-temperature (20 K) confocal microscopy, fluorescence spectra of isolated single CdS nanocrystals have been recorded. The narrowest measured line width of the main fluorescence band has been determined to be about 5 meV at the lowest excitation intensities. At higher intensities at least three additional observations are made: the main fluorescence band broadens, a line to the blue of the main peak evolves, and a peak due to the coupling to a longitudinal optical phonon appears.