Directed assembly of one-dimensional nanostructures into functional networks

One-dimensional nanostructures, such as nanowires and nanotubes, represent the smallest dimension for efficient transport of electrons and excitons an d thus are ideal building blocks for hierarchical assembly of functional na noscale electronic and photonic structures. We report an approach for the h ierarchical assembly of one-dimensional nanostructures into well-defined fu nctional networks. We show that nanowires can be assembled into parallel ar rays with control of the average separation and, by combining fluidic align ment with surface-patterning techniques, that it is also possible to contro l periodicity. In addition, complex crossed nanowire arrays can be prepared with layer-by-layer assembly with different flow directions for sequential steps. Transport studies show that the crossed nanowire arrays form electr ically conducting networks, with individually addressable device function a t each cross point.