可拉伸大面积共轭聚合物薄膜微结构调控

可拉伸共轭聚合物薄膜光电器件是可穿戴柔性光电器件的重要组成部分。以往研究聚焦于化学结构改性或刚柔共混手段构建薄膜晶区堆叠和非晶区缠结，从而实现薄膜可拉伸性。然而，由于缺乏对共轭聚合物分子构象的系统性研究，薄膜晶区刚性链堆叠↔非晶区分子间缠结的平衡机制、有效的调控策略及其对薄膜机械性能和电子性能的影响存在大量的研究空白。本项目将以可拉伸大面积共轭聚合物薄膜为目标，以新型高迁移率共轭聚合物为研究载体，深入探究溶液初始构象的记忆效应和溶液成膜过程中相转变动力学对薄膜晶区堆积↔非晶区缠结等凝聚态结构的影响规律，揭示晶区堆积↔非晶区缠结平衡机制及其对薄膜机械性能和电子性能的影响，建立溶液状态—成膜动力学—薄膜晶区/非晶区性质—电子/机械性能之间的关联规律，实现共轭聚合物薄膜本征拉伸和高迁移率，并进一步开发出大面积可拉伸共轭聚合物薄膜印刷制备方法，为可拉伸大面积共轭聚合物薄膜光电器件的发展提供理论。

Stretchable devices based on conjugated polymers stand in the heart of the wearable organic optoelectronics. Previous work focuses on chemical tailoring or blending rigid and flexible materials for co-existence of π-π stacking and chain entanglement, with a consequence of stretchable film. However, due to lack of systematic and thorough theory on molecular conformation in stretchable films, there remains mysterious for the equilibrium mechanism between π-π stacking and chain entanglement, as well as the its influence on mechanical and electronic properties. This project will focus on microstructure design of conjugated polymer for mechanically, electrically stretchable and large area thin film. The applicant will thoroughly investigate the influences of pre-aggregation in solution and dynamical phase transformation during solution-processing on the morphological properties of conjugated polymer film, especially on π-π stacking and chain entanglement. Trade-off between mechanical and conductive properties will be investigated and its equilibrium mechanism will be revealed. Relationships between pre-aggregation, film formation dynamics, π-π stacking/chain entanglement, and mechanical/conductive properties will be established. Mechanically, electrically stretchable film and its large-scale fabrication will be demonstrated. These results will clearly provide quantitative insight into fabrication of high-performance large-area stretchable optoelectronics, and will greatly accelerate the industrial processes of organic optoelectronics.