Perovskite-Organic Tandem Solar Cells Via Mobile Defects Mitigation and Solution-Processed Interconnecting Layers

Perovskite and organic semiconductors exhibit analogous properties, including bandgap tunability, low-temperature solution processing, and high potential for lightweight applications. These similarities render them highly attractive for being integrated in multijunction architecture: perovskite-organic tandem solar cells (POTSCs). Nevertheless, the efficiency of POTSCs is limited by electrical losses, which stem from both the wide-bandgap (WBG) perovskite layers and the interconnecting layers (ICLs) between two subcells. These two essential components also constrain the tandem device stability. In this study, we identify the underlying cause of open-circuit voltage ( V _OC ) losses in WBG perovskites, which is ascribed to the presence of mobile defects distributed at surface region. We further employ effective passivation agent with functional chemical groups to facilitate the healing of the mobile defects, thereby enhancing the V _OC to 1.35 V for WBG perovskite solar cells with a bandgap of 1.81 eV. Subsequently, we develop a solution-processed graphene oxide layer ICLs for tandem application, which not only reduces electrical losses but also improves tandem device stability. The synergistic integration of these two strategies has enabled POTSCs to surpass 25% efficiency while simultaneously achieving enhanced operational stability.