Highly improved lifetimes of solar cells comprising post-additive-soaked PTB7-F20:PC71BM bulk heterojunction materials

Highlights: • Lifetimes of PSCs comprising PTB7-F20:PC₇₁BM were highly increased by using PAS. • Above increase resulted from improved carrier generation and transport dynamics. • Deactivation of burn-in loss also contribute to the long device lifetime. Herein, we demonstrate that the lifetimes of polymer-based solar cells comprising PTB7-F20:PC₇₁BM composites can be significantly increased by using post-additive-soaked bulk heterojunction (BHJ) films. Analyses of solar cell performance, film morphology, time-resolved photoluminescence, and photoconductivity revealed that the above increase resulted from the combined effects of the improved carrier generation and transport in post-additive-soaked BHJ films and the efficient deactivation of burn-in loss by using the photochemically stable PTB7-F20 polymer.