Dark Ionic Liquid for Flexible Optoelectronics

Owing to a wide visual angle, few aberrations, and great depth of focus, flexible optoelectronics have become one subject of intense investigation for rescue equipment and endoscopy tools. Ionic liquids are rising as a kind of fluidic “semiconductor” with advantages of high flexibility and self-healing. However, challenges in the molecular design of photoresponsive ionic liquids impede the exploration of ionic liquids as intrinsic flexible liquid optoelectronics. This work demonstrated an imidazole-based ionic liquid covalently linked with a polypyrrole oligomer by alkyl chains. Such an ionic liquid has wide absorption from the visible light range to the near-infrared light range. The imidazole moiety acts as an electrical conductor which is thermally responsive. On the other hand, the polypyrrole segment serving as a light antenna is able to convert light energy to thermal heat. The alkyl linker tailors the energy transfer between polypyrrole and an imidazole cation. Negligible molecular aggregation and ...