All-Dry Deterministic Transfer of Thin Gold Nanowires for Electrical Connectivity

Metallic nanowires (NWs) exhibit a number of interesting properties, such as high conductivity, flexibility, and cold-weldability, making them ideal for nanocircuits. They are usually adsorbed on substrates by depositing a colloidal solution of NWs on the surface. However, they remain randomly scattered and solvent residues may contaminate/ degrade the sample. This study presents a method for forming electrical contacts with gold nanowires based on all-dry deterministic transfer. The process begins with the adsorption of gold nanowires by drop casting the colloidal solution onto a viscoelastic substrate. These wires are transferred to selected locations on the substrate, minimizing manipulation with fabrication times a factor of 2 shorter than direct drop casting deposition, preserving surface and sample conditions, and improving the fabrication of nanocircuits. Atomic force microscopy is used to manipulate the NWs for the final connections, which have contact resistances of a few ohms. To illustrate the technique, three different examples of applicability are presented. This work is expected to be a starting point for expanding the potential of deterministic transfer that is successfully used in 2D materials. For example, to study local electrical transport in heterogeneous samples such as van der Waals heterostructures and twisted layers of 2D materials.

Automated summary

Metallic nanowires with high conductivity, flexibility, and cold-weldability are ideal for nanocircuits. This study presents a method for forming electrical contacts with gold nanowires based on all-dry deterministic transfer, which improves fabrication and preserves sample conditions. Atomic force microscopy is used for manipulating the nanowires, resulting in low contact resistances. The technique has potential applications in studying electrical transport in heterogeneous samples and twisted layers of 2D materials.