Dimensional perspectives on metal center associated electrochromism in metal-organic coordinated hybrid polymers: Unveiling electrochromic dynamics

Electrochromic devices (ECDs), which can alter their color hue by external bias, have been considered as the potential entrants for the applications in power-saving smart windows, high-performance dynamic digital displays for future generation, e-paper, wearable electronics, and electrochromic sensing technology owing to their advantages of low power utilization, eye-friendly approaches for displays, simple and adjustable redox chemistry, etc. Starting from the metal oxides to today’s metal plasmonic-based electrochromic materials (ECMs), metal–organic polymers are superior due to their ease of processability, cost-effectiveness, wide and vivid color range, and other EC parameters like switching time, durability and coloration efficiency. Even if the metal–organic hybrid polymers are superior, the EC parameters like durability, color modulation, switching fastness, coloration efficiency, and EC memory must be further improved to commercialize next-generation ECDs. In recent years, with the cooperative efforts of numerous outstanding researchers in the field of metal–organic coordinated hybrid polymers, these technical bottlenecks can be solved in some portion by introducing new kinds of strategies and materials to fabricate ECDs with excellent performances. This review reports exciting state-of-the-art results regarding the structure and EC property relationship of new and unique different dimensional metallo-organic hybrid polymers for ECDs where the electrochromism is associated with the metal center redox. Meanwhile, the review also probes the EC properties of hybrid polymers and correlates them with their structures, mechanisms, features, morphologies, etc. A critical conclusion regarding this field’s remaining challenges and outlook is also proposed. Expectantly, this review can stimulate more researchers to enrich the field of metal–organic coordinated polymer for ECDs to tune the performance of ECDs by improving the key EC parameters for future development.