Design of independent and radiation modulation enhanced electrochromic windows in visible and infrared ranges

Electrochromic windows regulate the transmission and absorption of sunlight according to environmental conditions and personal preferences, resulting in energy conservation. However, developing smart windows that can independently modulate visible and infrared (IR) radiation remains a significant challenge. This paper presents a multilayer film structure for electrochromic windows based on the electro-optic dielectric material of 4-dimethyl-amino-N-methyl-4-stilbazoliumtosylate (DAST), and the film modulates visible and IR light individually. The refractive indices of multilayer DAST films change when different bias voltages are applied, which alters the structure's impedance and selectively modulates electromagnetic wave transmission. Simulation results indicate that the smart window can independently modulate the integrated visible transmittance (Tvis) and integrated infrared transmittance (TIR) at four different bias voltages (-20 V to + 20 V). The modulation ranges for Tvis and TIR are 72.5% to 92.3% and 46.1% to 95.2%, respectively, and the theoretical results surpass those of recent works. A fully-connected network with position coding is employed here, and simulation time is reduced based on truth prediction data. The multilayer structure proposed enables independent modulation of visible and IR light, making it a promising candidate for smart windows since it is lithography-free, large-area compatible, and polarization-independent.