Greater miscibility and energy level alignment of conjugated polymers enhance the optoelectronic properties of ternary blend films in organic photovoltaics

摘要

In this study, we examined the effects of using the p-type conjugated polymers J51 and FATZ as the third component in PM6:Y6-based donor:donor:acceptor (D:D:A) ternary organic photovoltaics (OPVs). We used UV-Vis spectroscopy, photoluminescence spectroscopy, atomic force microscopy, and grazing-incidence wideangle X-ray scattering to investigate the optoelectronic and morphological properties of the resulting ternary blend films. We evaluated the carrier transport properties of these OPVs to identify the mechanism governing their power conversion efficiencies (PCEs). Of our two tested polymers, FTAZ had more suitable energy levels and miscibility; therefore, its presence increased the open-circuit voltage of the resulting ternary device. The embedded FTAZ facilitated the molecular packing of Y6 and improved the charge transport in the ternary blend, thereby improving the PCE of the device from 14.3% (binary) to 15.3% (ternary).