Solar-Powered Ambipolar Electrochromic Polyimidothioethers Via Perovskite Photovoltaics

In this work, we demonstrate for the first time the novel electrochromic devices based on a series of ambipolar polyimidothioethers (PITEs) driven by state-of-the-art solution-processed perovskite solar cells. These devices with high color contrast and fast response time can have a low operating voltage, less than one volt. The electrochromic PITEs were prepared from new triphenylamine-based bismaleimides and commercial dithiols via Michael polyaddition. These polymers were readily soluble in various organic solvents and showed thermal stability associated with high glass-transition temperatures. The perovskite solar cell developed in our lab has a power conversion efficiency greater than 15% and open circuit voltage of 0.8-0.9 V, rivals the efficiency and cost of silicon solar cells in converting sunlight to electricity. Combined the innovative developments of both perovskite photovoltaics and ambipolar electrochromic materials, we have achieved a novel design of smart materials devices with strong commercial implications.