Transparent and Mechanically Resistant Silver-Nanowire-Based Low-Emissivity Coatings.

Area of Science:

• Materials Science
• Nanotechnology
• Optics

Background:

• Transparent conductive films are crucial for energy-efficient applications like smart windows.
• Silver nanowire (AgNW) networks offer a promising route to transparent low-emissivity (low-E) coatings.
• Poor mechanical adhesion of AgNWs has limited their practical implementation.

Purpose of the Study:

• To fabricate and investigate transparent low-emissivity coatings based on silver nanowire networks.
• To develop effective encapsulation methods to enhance the mechanical durability of AgNW coatings.
• To evaluate the optical and mechanical performance of the improved low-E coatings.

Main Methods:

• Fabrication of random networks of silver nanowires (AgNWs).
• Development of encapsulation techniques: spatial atomic layer deposition of alumina and solution processing of polysiloxane varnish.
• Characterization of optical transmittance and emissivity, alongside mechanical resistance testing.

Main Results:

• Achieved low emissivity (as low as 0.21) with high transparency (78%) for bare AgNW films.
• Developed mechanically robust AgNW coatings with low emissivity (0.34) and high transparency (74%) after encapsulation.
• Demonstrated a physical model explaining the relationship between emissivity and transparency in AgNW networks.

Conclusions:

• Encapsulated AgNW coatings exhibit excellent optical properties and enhanced mechanical resistance.
• The developed fabrication and encapsulation processes are cost-effective and scalable.
• These robust low-E coatings are highly suitable for applications such as energy-saving smart windows.