Multi-Component Collaborative Step-by-Step Coloring Strategy to Achieve High-Performance Light-Responsive Color-Switching.

Light-responsive color-switching materials (LCMs) are long-lasting hot fields. However, non-ideal comprehensive performance (such as color contrast and retention time cannot be combined, unsatisfactory repeatability, and non-automated coloring mode) significantly hinder their development toward high-end products. Herein, the development of LCMs that exhibit long retention time, good color contrast, repeatability, and the property of automatic coloring is reported. The realization of this goal stems from the adoption of a bio-inspired multi-component collaborative step-by-step coloring strategy. Under this strategy, a conventional one-step photochromic process is divided into a "light+heat" controlled multi-step process for the fabrication of the desired LCMs. The obtained LCMs can effectively resist the long-troubled ambient-light interference and avoid its inherent yellow background, thereby achieving the longest retention time and good repeatability. Multiple colors are generated and ultra-fast imaging compatible with the laser-printing technology is also realized. The application potential of the materials in short-term reusable identity cards, absorptive readers, billboards, and shelf labels is demonstrated. The results reported herein can potentially help in developing and designing various high-performance, switchable materials that can be used for the production of high-end products.