Dynamic smart window over the entire solar spectrum using a dry deposited device for sustainable architecture

Abstract

We developed a dynamic smart window capable of demonstrating transparent, black, and mirror modes across the entire solar spectrum. We demonstrated that the surface-roughness-controlled WO3 film deposited by nano particle deposition system (NPDS) can achieve the black mode with almost zero solar heat transmittance (Tsol). In the Reversible Metal Electrodeposition (RME), device can block heat similar to the mirror mode. NPDS is a unique dry deposition method to enhance the light scattering effect. As a result, the transmittance was measured in the range of the entire solar spectrum (λ ∼ 300 nm–2500 nm), obtaining 0.81% and 0.56% of Tsol for the black and mirror modes, respectively. However, 61% of Tsol was obtained for the transparent mode, confirming stark differences in Tsol. Furthermore, a dynamic smart window of 4 cm2 in size was fabricated to study the temperature change within the model house upon exposure to an infrared lamp to monitor any increase in temperature during transparent, black, and mirror modes. As a result, the temperature increases within the model house during transmittance mode increased by 19.2 °C, while the temperature increases during black and mirror modes slightly by 4.1 °C and 3.8 °C, respectively. The dynamic smart window was able to reduce the indoor temperature by more than 4.7 folds during the black/mirror modes. These findings confirmed that we developed an RME device capable of completely blocking sunlight to minimize indoor temperature change across the entire solar spectrum.