Self-Assembly of Gold Nanoparticles on Nanometre-PatternedSurface

Abstract

The self-assembly processes of gold nanoparticles onnanometre-step-patterned Si surface and polished Si surface areinvestigated by the convective self-assembly method. The convectiveself-assembly method is used to deposit the colloids dispersed inbenzene onto the substrates. The SEM results show that theconfigurations of the gold arrays depend on the surface morphology ofthe substrates. On the nanometre-step-patterned Si surface, thenanoparticles self assemble into parallel lines, and the distancebetween the neighbouring lines is around 35 nm. On the polished Sisurface the nanoparticles form compact domains. In each domain theparticles are close-packed in a two-dimensional hexagonal superlatticeand are separated by uniform distances. The analysis shows that on thenanometre-step-patterned Si surface, the steps play critical roles inthe self-assembly process of gold nanoparticles. The capillary forcefrom the steps drives the particles to lines along the steps.Therefore, the particles tend to self-assemble into one-dimensionalline structures when the solvent evaporates. For the polished Sisubstrate there is a little difference that the particles formtwo-dimensional hexagonal superlattices without the directionalconfinement.