Tunable conductive nanoparticle wire arrays fabricated by convective self-assembly on nonpatterned substrates

Area of Science:

• Materials Science
• Nanotechnology
• Surface Science

Background:

• Ordered nanoparticle arrays are crucial for advanced electronic devices.
• Bottom-up fabrication methods offer cost-effective and scalable production pathways.
• Controlling nanoparticle assembly at interfaces presents a significant challenge.

Purpose of the Study:

• To develop a method for fabricating centimeter-long ordered nanoparticle wires.
• To investigate the self-assembly mechanism of gold nanoparticles into wires.
• To control the orientation and geometry of nanoparticle wire arrays.

Main Methods:

• Convective self-assembly of 18 nm gold colloids from aqueous suspensions.
• Utilizing flat silicon dioxide on silicon (SiO(2)/Si) substrates.
• Controlling substrate temperature and meniscus translation speed during assembly.

Main Results:

• Fabrication of centimeter-long, ordered arrays of gold nanoparticle wires without prepatterning.
• Switchable orientation of wires (parallel or perpendicular to the contact line) controlled by substrate temperature.
• Tunable wire geometry (width, thickness, spacing) via meniscus speed.
• Achieved metallic resistive behavior with resistivity values as low as 5 × 10(-6) Ωm for multilayer wires.

Conclusions:

• A simple, low-cost bottom-up strategy for fabricating conductive nanoparticle wire arrays has been established.
• The study elucidates distinct mechanisms governing parallel and perpendicular wire formation.
• These conductive nanoparticle arrays hold promise for the development of novel nanoparticle-based functional devices.