Title : Durable surface-confined metal-terpyridine architectures for electrochromic applications
Abstract:
Electrochromic (EC) devices, including “smart” windows, are promising energy-saving technologies that can reduce building energy consumption by dynamically controlling the transmission of light and heat. These devices exploit electrochromism- the reversible change in colour or optical transparency induced by a small applied voltage. EC materials based on transition-metal complexes offer an attractive alternative to conventional inorganic systems because they provide low-cost, molecularly tunable optical properties without requiring noble metals. We developed multiple methodologies to create surface-confined, efficient, and robust EC materials based on monolayers or oligomers of late transition-metal complexes (Fe, Ru, and Os) covalently embedded on surface-enhanced, conductive, screen-printed metal-oxide supports.1 We demonstrated that molecular structures-including both the metal complexes and their anchoring linkers—can be tuned prior to deposition or modified directly on the surface to control the colour, switching behaviour, and stability of electrochromic monolayers.2 Our approach further enables the integration of different transition-metal complexes within a single conductive support, allowing selective electrochemical addressing of individual metal centres and enabling multiple colour-to-colour transitions within one film. Through controlled deposition strategies, we demonstrated sequential access to multiple coloured states and effective “colour mixing” directly on the surface.3 We also established that tailoring the composition, morphology, and porosity of the conductive support can substantially enhance colouration efficiency and provide exceptionally long-term operational stability.4 Beyond optical switching, we explored the energy-storage capabilities of hybrid electrochromic devices and investigated their electrochemical kinetics and plausible degradation pathways.5 Finally, we developed novel double-sided device architectures capable of operating in both unilateral and bilateral switching modes, demonstrating unprecedented durability (100,000+ cycles) while maintaining high electrochromic performance.6-7
