This award is made in the Advanced Materials and Processing Program by the Chemistry Division in support of Dr. Andrew Barron's research on gallium and indium chalcogenide molecules, phases and applications. Specifically, Group III/VI complexes will be prepared with geometries which will transform into predictable solid phases upon thermal chemical vapor deposition. Additionally, deposition of these new solid phases on gallium arsenide semiconductor surfaces will provide lattice-matched films that will passivate the surface. As an example, gallium sulfide precursors have been prepared which form a new cubic phase of gallium sulfide. The goal of the research is to extend these results, including the electronic characterization of, and development of applications for, the new cubic phase. New metalorganic chalcogenide compounds of indium and gallium will be synthesized and used for growth of indium and gallium chalcogenide thin films, both of known and new phases. An ultimate goal is the fabrication and testing of actual devices based on these films. %%% This research will extend both the fundamental chemistry and the practical photovoltaic and optoelectronic applications of new III/VI solid state materials.