Low-Energy Consumed Switchable Windows with Ultralong Optical Memory via Semiconductor-Enabled Reversible Zinc...

Area of Science:

• Materials Science
• Energy Science
• Building Technology

Background:

• Electro-response switchable windows (ERSWs) are crucial for zero-energy buildings but suffer from poor bistability and parasitic heat re-emission.
• Existing ERSWs have limitations in energy efficiency and thermal management due to their operational characteristics.

Purpose of the Study:

• To design and prepare a bistable reflectance-modulated electroreflective device (ZERD) for ultra-low-power heat management.
• To overcome the limitations of conventional ERSWs regarding energy efficiency and thermal control.

Main Methods:

• Developed a ZERD utilizing reversible zinc electrodeposition with a dynamic balancing strategy for redox reactions.
• Achieved excellent bistability (28 days) and fast switching speeds (4s colored, 8s bleached).
• Characterized reflectance modulation, solar reflectance (R_sol), and solar heat gain coefficient (SHGC).

Main Results:

• The ZERD demonstrated high R_sol (64.25%) and low SHGC (0.066), significantly reducing parasitic heat re-emission.
• Outdoor tests showed enhanced cooling performance compared to transmittance-modulated ERSWs, with a maximum temperature reduction of 8.4°C.
• Calculations revealed ZERD consumes only 0.8% of energy savings, enabling up to 57.9% annual energy savings.

Conclusions:

• The bistable reflectance-modulated ZERD offers a high-performance, ultra-low-power solution for heat management in buildings.
• This technology represents a significant advancement for ERSWs and contributes to the development of zero-energy buildings.