Аннотация:Solar energy is currently considered as a promising environmentally friendly technology. It is believed that the development of new polymeric materials for use as the basis of photoactive layers will allow to the create high-tech plastic solar cells (PSC) capable to generate cheap electric power. Since PSC efficiency has already exceeded 10%, their commercialization is becoming more and more attractive. However, a significant obstacle to PSE introduction into everyday practice is the extremely low durability of such devices due to the gradual phase separation of the initial components (usually, it is fullerenes blended with conjugated polymers) occurring in them under the influence of sunlight. Thus, finding the critical factors for controlling the nanocomposites thermal stability based on conjugated polymers is a significant problem.It is assumed that the mixtures of conjugated polymers (CPs), with a sufficiently large distance between side chains, filled with fullerenes, can form co-crystals, which can be highly stable and withstand many repeated heating/cooling cycles. We expect that the revealing the conditions for the formation of the co-crystals in mixtures of CPs with fullerenes can significantly increase the duration of operation of photocells based on polymers due to the formation of sterically stabilized structures.The report discusses mesoscale simulations of a nanocomposite based on poly- (2,5-bis (3-hexadecylthiophen-2-yl) thieno [3,2-b] thiophene) (PBTTT) filled with modified PC61BM and PC71BM fullerenes. All calculations were performed using the method of dissipative particle dynamics. We use a poly (3-hexyl-thiophene) / PC61BM-based nanocomposite as a reference system. We have chosen the ratio of polymer/fullerene volume fractions as the main parameter of the model. Additionally, we vary the solubility parameters of the main chain, side chains, and the functional group of fullerenes to check the effect of errors in determining these parameters on the evolution of systems under investigation.