Spectroscopy of the two lowest exciton zero-phonon lines in single CdSe/ZnS nanocrystals

Abstract

We study the optical properties of the lowest-energy exciton states in highly photostable individual CdSe/ZnS nanocrystals at low temperatures. We observe two sharp zero-phonon lines which we attribute to the radiative recombination from the two lowest-energy levels of the band-edge exciton fine structure. By using resonant laser excitation on these two lines we measure a spectral broadening of 10 μeV over integration times of 100 ms. © 2010 IOP Publishing Ltd.