Stable Organic Solar Cells Enabled by Simultaneous Hole and Electron Interlayer Engineering

The development of high-performance organic solar cells(OSCs)with high operational stability is essential to accelerate their commercialization.Unfortunately,our understanding of the origin of instabilities in state-of-the-art OSCs based on bulk heterojunction(BHJ)featuring non-fullerene acceptors(NFAs)remains limited.Herein,we developed NFA-based OSCs using different charge extraction interlayer materials and studied their storage,thermal,and operational stabilities.Despite the high power conversion efficiency(PCE)of the OSCs(17.54%),we found that cells featuring self-assembled monolayers(SAMs)as hole-extraction interlayers exhibited poor stability.The time required for these OSCs to reach 80%of their initial performance(T_(80))was only 6h under continuous thermal stress at 85℃in a nitrogen atmosphere and 1 h under maximum power point tracking(MPPT)in a vacuum.Inserting MoO_(x)between ITO and SAM enhanced the T_(80)to 50 and~15 h after the thermal and operational stability tests,respectively,while maintaining a PCE of 16.9%.Replacing the organic PDINN electron transport layer with ZnO NPs further enhances the cells'thermal and operational stability,boosting the T_(80)to 1000 and 170 h,respectively.Our work reveals the synergistic roles of charge-selective interlayers and device architecture in developing efficient and stable OSCs.