Achieving the high charge mobility of conjugated polymers under cyclic stretching by changing the interaction parameter between solvent and sidechain. (9th May 2023) - Zhang, Lu
Abstract: Conjugated polymers have been well-known as a critical candidate for stretchable electronics applications. However, further research is still needed to fully understand what kind of film morphology is beneficial to keep the charge mobility under cycling deformation. Herein, we proposed that the co-deformation of crystalline domains and amorphous regions can effectively dissipate strain energy. To verify our idea, we developed three kinds of the morphology of a diketopyrrolopyrrole-based polymer (DPP-TVT) with different crystallinity by changing the interaction parameter between solvent and sidechain ( R a solvent-sidechain ). The films cast from TCB with medium crystallinity exhibited 100% mobility retention (0.42 cm 2 V −1 s −1 ) under 100% strain and after 100 stretch-release cycles at 50% strain. However, the mobility of CN films with high crystallinity decreased from 0.45 to 0.23 cm 2 V −1 s −1 under a single stretch at 100% strain, while the performance of CF films with low crystallinity decreased from 0.34 to 0.052 cm 2 V −1 s −1 after 100 stretch-release cycles at 50% strain. The optimized performance of TCB films stems from the fact that the dispersed crystallites embedded in the amorphous matrix provide an efficient and robust charge transport network under single and repeating deformation. This research would aid in manipulating the mechanical and electrical properties of conjugated polymers. Graphical abstract: Image 1 Highlights: Simply solvent processing. High fatigue resistance. Crystallinity-stretchability relation.