Tetra-Fish-Inspired aesthetic thermochromic windows toward Energy-Saving buildings

The development of architectural windows with adaptive solar modulation is promising to reduce the energy consumption of heating, ventilation, and air conditioning (HVAC). In the work, we report a Tetra-fish-inspired aesthetic thermochromic window based on phase-changed materials to meet both energy-saving and aesthetic demands. We demonstrate the glasses coated with photonic co-doped vanadium dioxides, which exhibit the angle-dependent vivid colors mimicking the skin of tetra fishes with high transmittance, a practical transition temperature, and an acceptable solar modulation property. The glasses give superior energy-saving performances in representative cities in the Asia Pacific, resulting in annual energy savings of up to ~ 35.9 kWh/m2 for a typical office building. The work may inspire the future development of novel materials in building envelopes.