Efficient and stable perovskite solar cells based on insulating polymer modified ZnO nanoparticles

Abstract

In recent years, perovskite solar cells (PSCs) have achieved significant advancements in power conversion efficiency (PCE), with zinc oxide (ZnO) commonly used as an electron transport layer (ETL) due to its favorable properties. However, ZnO nanoparticles (NPs) often lead to poor-quality films, affecting electronic transmission and perovskite film growth, thereby limiting device performance. To address these issues, this study proposes a straightforward, cost-effective, and widely applicable strategy. By incorporating polyvinyl alcohol (PVA) into ZnO NPs, we achieved a denser, smoother, and more uniform ETL. This modification also optimizes the interface contact between the perovskite active layer and the ZnO NPs ETL. As a result, the PCE, short-circuit current density (J_SC), and fill factor (FF) of PSCs with PVA-modified ETL improved significantly compared to the control devices, increasing from 17.59% to 19.89% and from 15.03% to 16.56% for CsFAPbI₃ and MAPbI₃ perovskite structures, respectively. Furthermore, the mixed ETL of PVA and ZnO NPs notably enhances the environmental stability of PSCs. This approach, combining an insulating polymer with ZnO NPs, offers a simple and economical pathway towards the commercialization of high-performance PSCs.