Manipulating Film Morphology of All-Polymer Solar Cells by Incorporating Polymer Compatibilizer

Morphology control in multiblend all-polymer solar cells is crucial for improving charge generation processes. Herein, it is demonstrated that the film morphology of the light-harvesting layer of all-polymer solar cells can be manipulated by incorporating a copolymer as the compatibilizer. Through in situ grazing-incidence wide-angle X-ray scattering characterization, the insights of the crystallization kinetics of the polymer blends from solution to thin-film state are provided. Of particular importance is that by kinetic and thermodynamic control of the film-processing conditions, an optimal morphology with appropriate nanoscale fibrillar structure in a well-mixed matrix is achieved. These findings indicate that the interplay between the crystalline regions and weakly/noncrystalline regions that are induced by the compatibilizer polymer plays a critical role in determining the morphology in multicomponent blend all-polymer solar cells.