Employing structurally similar acceptors as crystalline modulators to construct high efficiency ternary organic solar cells

Abstract

Two structurally similar acceptors ITIC and IT-4F with complementary absorption spectra were employed to construct high-performance ternary blend polymer solar cells (PSCs) by combining a new polymer donor PBTA-PS. The ternary blend solar cell exhibits an outstanding power conversion efficiency of 13.27% with an enhanced short circuit current density (J_SC) of 19.60 mA cm⁻² and an excellent fill factor of 74.45%, which is higher than that of PBTA-PS:ITIC (IT-4F) binary solar cells. A wide photoresponse resulting in large J_SC, and good miscibility and compatibility of the three components guarantee the desired morphology and molecular packing in the ternary blend film, which improved the charge transport properties. Our results demonstrated that employing structurally similar acceptors is a promising strategy to enhance the molecular packing and realize high-performance ternary solar cells.