18.63% Efficiency of Ternary Organic Solar Cells Achieved via Nonhalogenated Solvent and Hot Spin-Coating Process

The solubility problem of conjugated polymers in nonhalogenated solvents limits the application of nonhalogenated solvents in Organic solar cells (OSCs). By combining with a hot spin-coating process, efficient PM6:BTP-BO-4F:GS-ISO ternary OSCs are prepared by employing o-xylene as a solvent. After adding 10 wt% content of GS-ISO to PM6:BTP-BO-4F, the surface morphology in the active layers is improved and the charge extraction, transport, and collection in OSCs are enhanced. Compared with the efficiency of PM6:BTP-BO-4F OSCs (16.25%), an efficiency of 18.63% is achieved for PM6:BTP-BO-4F:GS-ISO ternary OSCs. Moreover, PM6:BTP-BO-4F:GS-ISO ternary OSCs with an efficiency of 14.13% are prepared in air. The work provides a new strategy for preparing efficient and environmentally friendly OSCs using green solvents. Addition of 10 wt% GS-ISO to PM6:BTP-BO-4F improves the surface morphology of the active layer by employing a green solvent (O-xylene) and a hot spin-coating process, resulting in enhanced charge extraction, transport, and collection. The final result is the simultaneous enhancement of VOC, JSC, and FF as well as the realization of 18.63% efficiency. image