Acid Solution Processed VO₂-Based Composite Films with Enhanced Thermochromic Properties for Smart Windows

Area of Science:

• Materials Science
• Nanotechnology
• Optics

Background:

• Thermochromic vanadium dioxide (VO2) coatings modulate near-infrared (NIR) light transmission for smart windows.
• Pure VO2 suffers from low luminous transmittance and insufficient solar modulation efficiency, limiting its practical use.

Purpose of the Study:

• To enhance the thermochromic performance of VO2 films for improved smart window applications.
• To develop a facile method for creating porous VO2-based composite films with superior optical properties.

Main Methods:

• Magnetron sputtering was used to deposit VO2 films.
• A subsequent acid solution process utilized Zn2V2O7 particles as sacrificial templates to create porosity.
• The structural and optical properties of the films were characterized.

Main Results:

• The porous VO2-based composite film exhibited excellent luminous transmittance (72.1%).
• An enhanced solar modulation efficiency (ΔTsol) of 10.7% was achieved compared to pure VO2 films.
• The porous structure improved luminous transmittance, while isolated VO2 nanoparticles showed localized surface plasmon resonance (LSPR) effects.

Conclusions:

• The developed porous structure significantly improves luminous transmittance.
• Localized surface plasmon resonance (LSPR) in isolated VO2 nanoparticles enhances solar modulation efficiency.
• This method offers a promising route for fabricating VO2 films with excellent thermochromic performance for smart windows.