Structural and transport properties of directly assembled nanowires

Abstract

Scope and Method of Study: In this work, we present a systematic study on the assembly and characterization of nanostructures. We employed self and directed assembly methods in order to organize nanostructures. Quantitative film balance studies of self-assembled semiconductor nanoparticles enabled the determination of their effective interparticle potential. As a directed-assembly method, dielectrophoresis was used in the fabrication of interconnects from dispersions of nanostructures between targeted points in external circuitry. Directed electrochemical nanowire assembly (DENA) was developed and used in the fabrication of metallic nanowires from simple salt solutions. The structural and charge transport properties of the assembled nanostructures and the DENA-grown nanowires were characterized.

Findings and Conclusions: The CdSe nanoparticles of a given diameter were found to behave like hard-disks with significantly smaller diameters. This behavior was attributed to an attractive contribution to the interparticle potential, such as the dipolar potential. We found that nanoparticulate CdS converts to bulk CdS during dielectrophoretic interconnect fabrication. We demonstrated that the dielectrophoretic interconnects fabricated from gold nanorods are nanostructured, limiting their conductivity. DENA technique enabled the single-step growth and low-resistance interconnecting of crystalline diameter-tunable metallic nanowires. The preliminary results of the diameter-dependent resistivity studies with the DENA-grown gold nanowires were consistent with the predicted behavior.