Fabry-Pérot cavity-engineered smart windows with enhanced dynamic radiative cooling and solar modulation

The passive dynamic radiative cooling (PDRC) smart window passively modulates long-wave infrared (LWIR) radiation intensity in response to ambient temperature, enabling passive cooling in summer and thermal insulation in winter. Nevertheless, significant challenges remain in simultaneously optimizing solar transmittance (T_sol), LWIR emissivity modulation (Δɛ_LWIR), and daylight harvesting. Herein, we constructed an adaptive bifunctional anti-reflection or high-reflection layer integrated with a Fabry-Pérot (F-P) cavity architecture comprising a top W_xV_1-xO₂ lay, a porous SiO₂ spacer, and a bottom FTO layer on a glass substrate. This design enables a remarkable improvement of ΔT_sol from 1.96 % to 6.45 % between high- and low-temperature states while maintaining strong LWIR emissivity modulation (Δɛ_LWIR = 0.48) within the atmospheric window (8–13 μm). The rough surface morphology of W_xV_1-xO₂ plays a critical role in enhancing both luminous transmittance (T_lum) and ΔT_sol. T_lum = 0.50 meets the minimum requirement for lighting in residential and office buildings, without generating additional lighting energy consumption during the day. Furthermore, energy consumption simulation verifies the application potential of the designed smart windows under diverse global climatic conditions. These design strategies broaden the spectral regulation range of PDRC smart windows and pave the way for their practical applications.