全共轭聚合物共混体系可有效解决聚合物/富勒烯共混体系光吸收能力差及LUMO能级高等问题，是国内外关注热点。不同于富勒烯分子光电特性为各向同性，共轭聚合物为各向异性分子，其光电性质依赖于分子取向。全聚合物共混体系给受体分子均为face-on取向时，利于电荷转移态分离及载流子传输，可降低单分子复合、双分子复合几率及能量损失。然而，多数共混体系中给受体分子为face-on/edge-on或edge-on/edge-on取向。本项目围绕如何使给受体转变为face-on/face-on取向这一问题，开展三方面研究：（1）控制共轭聚合物结晶的成核方式，利用外延结晶、受限结晶等原理实现分子取向控制；（2）控制溶液中共轭聚合物共混体系固-液相分离类型，协同控制成膜动力学，实现分子取向控制；（3）揭示给受体取向方式对单分子复合、双分子复合及能量损失等影响，阐明分子取向与光物理过程间联系。

Weak absorption ability and energetic tenability which are two fatal weaknesses in polymer/fullerene solar cells are effectively solved by all-polymer solar cells. As well known, fullerene is isotropic and could delocalize electrons in the three-dimensional directions, while conjugated polymer is anisotropic, as a result, its molecular orientation influenced the photophysical processes. Both the donor and acceptor adopt face-on orientation is favorable for the separation of CT state, charge transport, leading to reduced geminate recombination, charge recombination and energy loss. Therefore, our work will focus on the following aspects in this project: (1) Adjusting molecular orientation by controlling the heterogeneous nucleation and extension growth of conjugated polymer. (2) Combining solid-liquid phase separation and film-forming kinetics to promote the face-on orientation for polymers in blended system. (3) Based on molecular orientation control, illuminating the influence of the molecular orientation on geminate recombination, charge recombination and energy loss, elucidating the relationship between molecular orientation and photophysical processes in all-polymer solar cells.