Transparent radiative cooling cover window for flexible and foldable electronic displays

Area of Science:

• Materials Science
• Nanotechnology
• Optics

Background:

• Transparent radiative cooling is crucial for passive thermal management in electronic devices.
• Flexible electronics require cover windows with advanced optical, mechanical, and moisture-barrier properties.
• Existing solutions fail to meet the stringent criteria for foldable and flexible display applications.

Purpose of the Study:

• To develop transparent radiative cooling metamaterials for foldable and flexible display cover windows.
• To achieve efficient passive cooling without compromising optical transparency and device durability.
• To address the limitations of previous radiative cooling technologies in real-world applications.

Main Methods:

• Rational design and synthesis of optically-modulating microstructures embedded in clear polyimide.
• Fabrication of 50-micron thick transparent radiative cooling metamaterials.
• Integration of metamaterials as cover windows for electronic devices and displays.

Main Results:

• Achieved excellent light emission within the atmospheric window while maintaining high optical transparency.
• Demonstrated enhanced mechanical strength and superior moisture-impermeable properties.
• Substantially mitigated temperature rise in devices under solar irradiance and improved thermal management in dark conditions.
• Enhanced the light output performance of light-emitting diodes by suppressing thermalization-induced degradation.

Conclusions:

• The developed transparent radiative cooling metamaterials meet the demanding requirements for foldable and flexible display cover windows.
• This technology offers a viable solution for passive thermal management in outdoor electronic devices.
• The metamaterials significantly improve device performance and longevity by controlling thermal conditions.