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

초록

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 (T80) was only 6 h under continuous thermal stress at 85 °C in a nitrogen atmosphere and 1 h under maximum power point tracking (MPPT) in a vacuum. Inserting MoOx between ITO and SAM enhanced the T80 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 T80 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. © 2024 The Authors. Energy & Environmental Materials published by John Wiley & Sons Australia Ltd on behalf of Zhengzhou University.

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