Vanadium dioxide - Perovskite tandem smart windows achieve full-spectrum modulation via plasmonic Fabry-Pérot engineering

Conventional thermochromic windows are limited by their single-band modulation, which restricts their ability to simultaneously manage solar light and mid-infrared heat radiation. This study introduces a novel Full-spectrum Modulated Perovskite-based Smart Window (FMPSW) that can simultaneously regulate solar light transmittance and mid-infrared emissivity in response to thermal changes while maintaining high luminous transmittance. By integrating optical simulations with experimental validation, the optimized FMPSW design demonstrates exceptional energy-saving potential through the incorporation of Fabry-Pérot resonance and surface plasmon polaritons (SPPs). The optimized design achieves remarkable solar modulation (16 %) and emissivity modulation (33.4 %) simultaneously, with a cold-state luminous transmittance exceeding 40 %. Experimental results also show a maximum emissivity adjustment of 46 % without compromising high luminous transmittance levels. Furthermore, EnergyPlus simulations confirm the practical applicability of FMPSW, demonstrating significant energy savings across cold (Beijing), temperate (Shanghai), and sub-tropical (Hong Kong) climates. Specifically, the proposed window system achieves a 22.66 % annual cooling energy reduction in tropical climates compared to conventional glass, addressing critical urbanization challenges. This research not only advances the development of adaptive thermochromic windows but also establishes a pioneering material integration paradigm for sustainable architecture, particularly targeting energy-intensive urbanization in tropical regions. © 2025 The Authors.