Chromogenic WO3 toward smart windows: Bibliometric insights, film fabrication, and energy performance

Smart windows based on tungsten trioxide with chromogenic properties (WO-SWs) can dynamically regulate solar irradiance, offering great potential for energy-efficient buildings and carbon neutrality. This work conducts a bibliometric analysis of 457 publications (2014-2025) to outline the research status of WO-SWs, alongside a technical review of film fabrication and energy performance. Bibliometric findings reveal that electrochromism has attracted greater research attention than photochromism. This paper discusses mainstream WO-SWs fabrication techniques, including magnetron sputtering, electron beam evaporation, electrodeposition, solvothermal/hydrothermal, sol-gel, and inkjet printing. The relationship between processing parameters and achievable device performance is analyzed, with attention to the working principle and large-area manufacturing restrictions. State-of-the-art lab-scale performances include an optical modulation of up to 90.8%, cycling durability reaching 20000 cycles, switching time below 5 s, and a thermal regulation of 5-42.7°C. Cross-climate building-energy simulations predict annual HVAC energy savings of 10-51%, while life-cycle assessment demonstrates CO 2 emission reductions up to 14.4 kg m −2 ·a −1 . Nevertheless, these promising metrics face real-world barriers inherited from high manufacturing cost, long-term operational stability degradation, and poor compatibility with building systems. Future research priorities include operando ion-trapping characterization, scalable low-cost manufacturing, standardized testing protocols, and integration with energy storage and sensing. This review bridges the manufacturing and building application to facilitate practical technology selection.