A wearable alternating current electroluminescent device based on imidazole chloride ionogel films with high conductivity, stretchability and transmittance

Abstract

Ionogels combine the advantages of gel polymers and ionic liquids (ILs), and not only have high ionic conductivity but also have favorable flexibility and are suitable for wearable electroluminescent devices. Aiming at solving the problems of low conductivity, low transmittance and poor tensile properties of conductive hydrogels, a new ionogel with attractive properties is presented. The results show that 1-ethyl-3-methylimidazolium chloride (EmimCl) incorporated in polyvinyl alcohol (PVA) not only improves the conductivity of the gel as an ion providing agent, but also improves the mobility and self-healing rate of the polymer chain as a plasticizer. When the EmimCl content is 100 wt%, the ionogel has an ionic conductivity of 3.4 × 10⁻³ S cm⁻¹, an elongation at break value of 240%, and a light transmission of 94%. Based on the favorable flexibility, conductivity and light transmission of ionogels (PBE), flexible electroluminescent devices have been prepared with sandwich structures. The tested devices simultaneously exhibit high flexibility, high stability and considerable luminous intensity (3 V input, 114 cd m⁻², drive assist 50 V, 400 Hz), showing their potential application in the field of wearable devices.