Controlling Kinetic Quenching Depth Toward High-Performance and Photo-Stable Organic Solar Cells Printed from a Non-Halogenated Solvent

The investigation of drying dynamics and kinetic quenching depth related degradation of high-performance photoactive materials with scalable coating techniques demands significant research attention. Herein, film formation kinetics regulated crystallinity, preferential orientation and vertical phase separation of the active layers is revealed, which then further affects exciton diffusion, dissociation, charge-transport and recombination processes. By suppressing over aggregation/crystallization in slow drying process and overcoming quenching of disordered liquid phase in fast-dried films, the optimized PM6:BTP-eC9-based organic solar cells obtain power conversion efficiencies up to 16.81%. In addition, photoluminescence lifetime distribution is found to be an alternative probe for kinetic quenching depth that governs the degradation rate. This study provides valuable insights into the control of thin film formation kinetics during scalable processing and develops an effective way to associate the kinetic quenching depth with morphological degradation for mechanistic understanding of long-term stability.