Highly transparent light-harvesting window film

Area of Science:

• Materials Science
• Optics
• Renewable Energy

Background:

• Electrochromic glass requires dedicated power sources, complicating installation.
• Efficient solar energy capture in transparent windows is a significant challenge.

Purpose of the Study:

• To simulate novel textured window films for transparent solar energy harvesting.
• To enable self-powered electrochromic windows.

Main Methods:

• Simulated unique textured window films with embedded 35° cones.
• Coated cones with a five-layer SiO2-Ag stack to scatter infrared light.
• Analyzed light scattering, power generation, visible transmittance, and haze.

Main Results:

• Simulated design directs 1.4% of incident light to edge photovoltaic strips.
• Generated 1 W of power under specific solar conditions for a 1m x 1m window.
• Achieved 95% internal visible transmittance at normal incidence, maintaining >85% up to 60° viewing angles.
• Reported low haze (0.6% at normal incidence, 3.9% at 60°).

Conclusions:

• Textured window films offer a viable solution for transparent solar power generation.
• The simulated SiO2-Ag coated cones effectively harvest solar energy while preserving window aesthetics.
• This technology can lead to self-powered smart windows and improved building energy efficiency.