Locally Resolved Thermally Induced Degradation of PM6:Y6-Based Organic Solar Cells

The limited thermal stability of organic solar cells has hampered their commercialization. Therefore, it is crucial to gain in-depth insight into the underlying causes of thermal device instability and to develop practical approaches to reduce its impact. In this study, we examine thermal degradation processes of the donor/acceptor system PBDB-T-2F:BTP-4F (alias PM6:Y6) in bulk heterojunction polymer/nonfullerene acceptor (NFA) solar cells, considered as a state-of-the-art system of the organic photovoltaics (OPV) technology. More specifically, this study investigates the effects of varying postproduction annealing temperatures on the performance of solar cells and locally resolves the thermally induced impact on these solar cells using a set of advanced imaging techniques, including photoluminescence imaging (PLI), electroluminescence imaging (ELI), and light beam-induced current (LBIC) measurements.