ИСТИНА

Toward efficient polymer solar cells several key challenges have to be resolved, including improvement of light absorbance, managment of transport properties of free charge carriers, and nanomorphology of bulk heterojunction. Ternary systems, including the D1:D2:A system and D:A1:A2 system, is regarded as prospective approach to address these issues. We previously reported novel highly soluble double-caged fullerene acceptors (dFR) providing inhanced charge transport and molecular ordering in binary systems with P3HT as a donor component. Here we report fabrication, optimization, and testing of related photovoltaic devices with ternary active layer based on P3HT, dFR, and third component comprising a low band gap donor polymer or small-molecule/fullerene acceptors. Optimization of the fabrication protocol for ternary solar cells includes variation of donor/acceptor/third component ratio, thickness of photoactive layer, annealing temperature, and used solvent(s). Electronic properties of individual compounds as well as the active layer, including the HOMO and LUMO levels, the charge carrier mobility as well as the nanomorphology of photoactive layer will be discussed. The experimental composition-structure-property relationships for a representative series of ternary photovoltaic devices makes possible to reveal correlation between the molecular and electronic features of components of the active layer and its photovoltaic characteristics. This work was supported by RFBR (project № 18-33-00670).