Synergistic Titanium Intercalation in WO3 Architectures to Enhance Electrochromic Performance for Smart Windows

We report the successful synthesis of amorphous titanium-engineered tungsten oxide (WTi) films via a facile and cost-effective electrodeposition method. Unlike conventional high-temperature or vacuum-based techniques, our approach enables a scalable, all-solution process, ensuring efficiency and sustainability. X-ray diffraction (XRD) confirmed the amorphous nature of all films, a key factor in enhancing ion diffusion for superior electrochromic (EC) performance. Field-emission scanning electron microscopy (FESEM) revealed that an optimized nanoparticle network facilitates rapid charge transport and ion intercalation, while uncontrolled nucleation and grain growth hinder EC efficiency. By precisely tuning the Ti concentration, the optimized 3 at% WTi-3 film achieved outstanding EC properties, including an impressive optical modulation of 85% at 600 nm, exceptional reversibility of 95.61%, and a high coloration efficiency of 51.55 cm2/C. This study underscores the pivotal role of amorphous engineering and dopant concentrations in advancing high-performance EC materials, paving the way for next-generation smart windows and energy-efficient displays. Our findings highlight a transformative strategy for low-cost, high-efficiency EC devices, demonstrating unprecedented performance through precision-engineered material design.