Dark Ionic Liquid for Flexible Optoelectronics

Abstract

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 phase separation are attributed to the preservation of the fluidic nature at room temperature. This photoresponsive ionic liquid is successfully exploited as a flexible light detector that is adaptable to special sensing tests in bending states.

Ionic Liquid‐Based Stimuli‐Responsive Functional Materials

“…However, the synthetic procedures for such IL-based photo-responsive materials are relatively complicated and tedious. [121][122][123][124] The physicochemical properties of IL-based photo-responsive materials, such as melting points, [125] conductivities, [126] and fluorescence [127][128][129] could also be modulated by the light. For example, the photo-responsive PILs based on diarylethene units have been designed to achieve light-mediated conductivity changes, using imidazolium-containing diarylethene as ionic pendants covalently attached to a poly(ethylene oxide) backbone (Figure 20a-c).…”

“…An imidazole‐based IL covalently linked with a polypyrrole oligomer by alkyl chains have been demonstrated. [ 129 ] The resultant ILs had wide absorption from the visible light range to the near‐infrared light range. The imidazole unit served as an electrical conductor which was thermally responsive and the polypyrrole unit acted as a light antenna, which was able to convert light energy to thermal heat.…”

Research progress in ionic liquid-based multifunctional green electronic devices

“…Society 许可) Figure 6 Polypyrrole grafted near-infrared light-responsive ionic liquids [38] . 7 Liquid logic circuits based on ionic liquids [39] .…”

Soft Electronics Based on Liquid Conductors

“…As illustrated in Figure 17e, the pyrrole group on the ionic liquid of [C 6 MIm]Br could be polymerized into oligomers in the presence of oxidants. [ 110 ] The ionic liquid became a NIR light‐sensitive material without losing its fluidic performance. It output remarkable electrical responses and also had wonderful stability against repeated light illumination.…”