Formation of Au nanoparticles on Si bicrystals

Formation of Au nanoparticles on Si bicrystal has been investigated by transmission electron microscopy. The Au nanoparticles were found to form preferentially at the node points of the dislocation network to relieve the strains induced by the dislocations. Upon annealing at 150°C, the Au nanoparticles were found to be confined by the dislocation grids. Upon further annealing at 250°C, small nanoparticles shrank in favor of the large nanoparticles, with a size larger than the critical size, as a manifestation of the classical Oswald ripening process. The shrinkage of Au nanoparticles exhibited a stepped behavior in that clusters shrank by steps of dislocation grids. The effects of dislocation spacing on the morphology of Au nanoparticles were also observed and discussed.