N-type SAM Interlayer Phthalimide naphthalenediimide (PANDI) on Zinc Oxide for Effective Passivation and Enhanced Electron Transport in Organic Photovoltaics
In this study, we propose a strategy to overcome interface problems by introducing an n-type self-assembled monolayer (SAM) between the electron transport layer and the active layer of an organic solar cell (OSC). Zinc oxide (ZnO) is a key electron transport layer in inverted OSC structures, but the ZnO layer typically contains a large number of oxygen vacancies. These vacancies can trap electrons from the active layer, degrading device performance and stability. Introducing PANDI as a passivation interlayer can effectively reduce oxygen vacancies, lower the work function of ZnO layer, improving charge recombination and energy level alignment. This strategy can enhance power conversion efficiency through more efficient charge transport and improve stability in the OSC.