A STRAIGHTFORWARD, NEW METHOD FOR THE SYNTHESIS OF NANOCRYSTALLINE GAAS AND GAP

A new, low-temperature method has been established for solution-phase synthesis of nanocrystalline III-V semiconductors, namely, gallium arsenide and gallium phosphide. This new approach consists of in situ synthesis of the pnictides, (Na/K)3E (E = P, As), in toluene and their subsequent metathetical reactions with gallium halide solutions in coordinating solvents such as monoglyme and diglyme. The effect of solvent on the particle size is clearly evident. The reactions in which gallium halides were dissolved in toluene, a noncoordinating solvent, and 1,4-dioxane, a coordinating solvent, produced larger crystallites while the use of gallium halide solutions in monoglyme and diglyme solvents, known to cause dissociation of gallium halides and form chelate complexes, led to reduction in particle size by a factor of 2 or more. The nature of the gallium halide employed also influenced the particle size of the resultant materials. The III-V semiconductor quantum particles have been characterized by XRD, TEM, XPS, UV-vis, and elemental analysis. The blue-shifted UV-vis absorption spectra are clear evidence of quantum confinement in these nanoparticles.