Electronic spectroscopy of neutral indium phosphide clusters.

Electronic spectroscopy has been successfully applied for the first time to a broad distribution of small neutral clusters. Electronic predissociation and two-color resonant two-photon ionization spectroscopic techniques are used to investigate clusters containing between 3 and 12 atoms of the III-V semiconductor, InP. Both techniques provide intense signals which display marked wavelength dependence with cluster composition. These techniques promise to provide a variety of critical spectroscopic results for the entire series of small In sub x P sub y clusters entrained in the molecular beam, and can be extended to permit the study of many other types of clusters. This work addresses the critical need for experimental information about cluster structures in this size regime.