THE ROLE OF GA-DROPLET FORMATION IN NANOMETER-SCALE GAAS CLUSTER SYNTHESIS FROM ORGANOMETALLIC PRECURSORS

Recently we demonstrated the formation of crystalline nanometer scale GaAs clusters from organometallic precursors using an aerosol process derived from organometallic vapor phase epitaxy (OMVPE) [P. C. Sercel et al., Appl Phys. Lett. 61, 696 (1992)]. Here, we explore the influen ce of precracking the Ga precursor (trimethyl-gallium), forming nanome ter scale Ga droplets, prior to introduction of AsH3 to the reaction. We find the GaAs clusters so formed have an entirely different morphol ogy than do those formed when the reactants are pre-mixed prior to rea ction. This data supports our earlier contention that homogeneous nucl eation is the dominant reaction mechanism for the formation of the clu sters.