A dual-responsive smart window based on inorganic all-solid-state electro- and photochromic device

Dual-responsive smart windows combining electro- and photochromism (E/PC) represent a promising strategy to reduce building energy consumption and improve living comfort. These windows can adaptively adjust the indoor temperature as varying sunlight intensity, as well as actively regulating it by applying a low voltage. Unfortunately, their realization has been hampered by the scarcity of materials that can simultaneously respond to both electricity and light. Herein, we introduce the first inorganic all-solid-state devices capable of E/PC dual-response, which are constructed based on the composite of oxygen-vacancy WO3-x functionalized with ZnO nanoparticles (OV-WO3-x/ZnO). Benefiting from the synergistic effects of oxygen vacancies and OV-WO3-x/ZnO heterojunction at the a-c interface, the OV-WO3-x/ZnO films not only exhibit an advanced dual-band EC performance with high optical modulation (85.9% at 633 nm and 74.5% at 1000 nm) and fast response speed (tb/tc =3.1/5.5 s), but also deliver an enhanced PC response with a high optical modulation (86.1%) and remarkable reversibility. Furthermore, their smart window prototypes yield a significant temperature modulation of 5.3 °C and 4.7 °C through electro- and photochromism respectively, demonstrating their outstanding thermal regulation capabilities and energy-conserving potential. This work showcases a heretofore unexplored route for the design and development of energy-saving smart windows.