An efficient interface modification material for improved efficiency and stability in inverted organic solar cells

Interface engineering is a reliable strategy to simultaneously enhance the efficiency and stability of organic solar cells (OSCs). In this study, a molecule named NMA-C0 is designed and used as a modifying material on ZnO in inverted OSCs. With this modification, the organic-inorganic interface in the ZnO-based inverted OSCs was fine-tuned, achieving a reduced surface roughness, better energy level alignment, improved electron extraction and transport abilities. As a result, with PM6:L8-BO as the active layer, a significantly enhanced power conversion efficiency (PCE) of 18.31% for the ZnO/NMA-C0-modified device was realized compared to 17.51% for the control device with bare ZnO. Furthermore, compared to the control device, an obvious boost in both thermal stability and illumination stability was achieved for the NMA-C0 modified device. These results indicate that NMA-series ETLs could act as excellent molecular platforms of modifying ZnO to simultaneously improve the inverted OSC performance and stability. A hybrid ETL is reported for inverted structure OSCs by modifying ZnO with a molecule named NMA-C0. With the hybrid ETL, the device based on PM6:L8-BO achieves an efficiency of 18.31% with good thermal and photo stabilities.