Chemical Primary Color Pixels for Full‐Color Image Encoding and Decoding

Reflective displays use eye-compatible ambient light to showcase the image, thus featuring better readability and higher energy efficiency over the emissive displays. Primary colors suitable for reflective display can be easily produced via various chemical chromogenic reactions, but from primary colors to color pixels, assigning and instruction of binary data is essential, which in turn guide the generation of colorful images via encoding and decoding. Herein, we proposed a chemical primary color pixel strategy using Rose Bengal (RB, a derivative of the well-known logic gate molecule fluorescein), together with a chromogenic substrate 3,3',5,5'-tetramethylbenzidine (TMB), to achieve chemical primary color pixels. Specificall Yey, the pH-dependent photosensitization activity of RB was explored (oxidation of TMB) and combined with the pH-modulated refreshable TMB-based chromogenic reaction, which allowed the use of pH and light to dually modulate the chromogenic reaction for CMY primary color output. Meanwhile, such system could perform binary logic gates, and was capable of decoding and encoding the binary data of images. The resultant chemical primary color pixels featured a full-color gamut and facile refreshing, which permitted image display in a full-color reflective mode with a resolution of 51 PPI and extreme visual comfort.