A Transparent Long-Term Cooling Green Plant-Like Window for Net-Zero Energy Buildings

We report a bioinspired, transparent green plant-like window that integrates passive cooling, thermal insulation, and solar-driven waste heat recovery to reduce building energy consumption. By mimicking leaf transpiration, the system uses a carbon quantum dot-doped CPPB hydrogel to achieve high visible transmittance (~92%) while blocking UV and NIR radiation. A self-powered water circulation layer repurposes solar heat for domestic water heating. Outdoor field tests and 168-h solar simulator exposure confirm long-term thermal stability and cooling up to 21.9°C. Simulations across 30 global cities show annual cooling energy savings up to 569.1 MJ/m 2 . This scalable, multifunctional window offers a sustainable path toward net-zero energy buildings.