Spectroscopy of size-selected neutral silicon clusters: Remarkably similar spectra for clusters containing between ∼15 and 70 atoms

Absorption spectra have been recorded for gas phase, size-selected neutral silicon clusters using resonant one- and two-color photodissociation spectroscopy. We now have spectra between 0.94 – 5.58 eV for clusters containing up to 70 atoms. Starting at ～15 atoms, the spectra are all amazingly identical. Comparisons of the silicon cluster spectra to those of various forms of bulk silicon show that the cluster spectra have much in common with the spectrum of the most stable diamond structure of bulk crystalline silicon.