构建互穿网络结构中系带分子（tie chain）和缠结网络协同提升全聚合物太阳能电池力学与光伏性能

全共轭聚合物太阳能电池具备可同时实现高机械变形性和高光伏性能的潜力，适用于可穿戴电子设备的电源。然而，设计活性层形貌同步实现高力学性能和高光伏性能仍然面临较大挑战。增加互穿网络结构中非晶区域内的系带分子（tie chain）、缠结网络密度和降低结晶度是实现力学性能和光伏性能协同提升的关键科学问题。围绕这一问题，拟开展三方面研究：（1）聚合物给受体的分子量变化对共混薄膜力学性能的影响，临界分子量区间探索。（2）通过溶液晶核种，调控成核密度，协同成膜动力学控制结晶生长过程，增加tie chain与缠结网络含量，最终构筑相区逾渗网络结构。（3）探讨共混薄膜断裂机理，建立相区逾渗网络结构中tie chain和缠结网络密度与机械力学和电学性能间的关系。本项目研究结果可为同时兼备高力学和光伏性能的全聚合物太阳能电池活性层设计提供一定的指导。

All polymer solar cells have the potentials to realize high mechanical deformability and high photovoltaic performance simultaneously, making them suitable for power sources for wearable electronic devices. However, it is still a major challenge to design the morphologies of active layers to achieve high mechanical and photovoltaic properties simultaneously. Increasing the density of tie chain and entanglement network in the amorphous region of the interpenetrating network structure and decreasing crystallinity are key scientific issues to achieve the coordinated improvement of mechanical and photovoltaic properties. Three aspects of this research will be undertaken: (1) The influence of molecular weight change of donor and acceptor polymers on mechanical properties of blend films, and the range of critical molecular weight will be discovered. (2) The percolation network structure in the phase will be constructed by controlling the nucleation density through seed nucleation in the solution and film-forming kinetics. Some new methods will be established to increase the density of the tie chain and entanglement network. (3) The fracture mechanism of the blended films will be investigated, and the relationship between the density of tie chain and entanglement network in the percolation network structure in the phase and the mechanical and electrical properties will be established. This project will provide a certain research basis and theoretical basis for further improving all-polymer solar cells with both high mechanical and high photovoltaic properties.