Enhanced Efficiency and Excellent Thermostability in Organic Photovoltaics via Ternary Strategy with Twisted conjugated Compound

The thermal stability of high-efficiency organic photovoltaics (OPVs) is critical to the manufacturing of this technology. Therefore, targeted strategies and approaches shall be developed to improve efficiency and stability, simultaneously. Herein, a seleno twisted benzodiperylenediimides (TBD-PDI-Se) acceptor-doping strategy is taken advantage of to demonstrate the ternary bulk heterojunction OPVs with excellent stability, achieving outstanding power conversion efficiency of 14.43% and 17.25% based on PM6:IT-4F and PM6:Y6 ternary blend devices, respectively, which are superior to the corresponding binary devices. As evidenced by the active layer morphology, exciton dynamic study and the characterizations of the enabled device, the ternary blend device keeps nearly 90% original efficiency (t = 1000 h) under continuous constant heating at 140 degrees C. Furthermore, the application of acceptor as the third component in PBDB-T:ITIC, J71:ITIC, and PBDB-T:PC71BM systems is also verified, proving the good universality of acceptor-doping ternary strategy.

Automated summary

The study demonstrates the fabrication of high-efficiency and stable ternary bulk heterojunction organic photovoltaic devices using a seleno twisted benzodiperylenediimides acceptor-doping strategy. The devices achieved outstanding power conversion efficiency and maintained nearly 90% of the original efficiency under continuous heating. This ternary strategy was also shown to be universally applicable in various systems.