Electronic wavefunctions in semiconductor clusters: Experiment and theory.

This invited manuscript will appear as a "Feature Article" in the Journal of Physical Chemistry. A general discussion of the chemistry and physics of semiconductors clusters is given, assuming a familiarity with chemical valence theory but no knowledge of solid state physics. It has been discovered that liquid phase precipitation reactions can be controlled to make and stabilize crystalline semiconductor clusters in the size range ~ 15 to 100Angstroms. The cluster electronic properties can be studied optically in dilute colloidal solutions. The results indicate that the approach of cluster electronic wavefunctions to the bulk Bloch molecular orbitals is exceedingly slow as a function of cluster size. This result can be understood in terms of the intrinsic electron delocalization present in crystalline materials with strong, directional chemical bonding.