Emission spectrum and spectral diffusion of a single CdSe/ZnS nanocrystal probed by photon-correlation Fourier spectroscopy (PCFS)

Colloidal nanocrystals are very bright stable fluorophores obtained by chemical synthesis. By use of a confocal microscope, they can be studied at the single-emitter level. This reveals some properties which were hidden in ensemble measurements such as homogeneous emission linewidth. However, as nanocrystal emission exhibits strong fast spectral diffusion, the emission measured on a nanocrystal is still broadened by time averaging over the duration of one measurement (typically 100 ms) and the measured linewidths are typically a few