A copper-doped nickel oxide bilayer for enhancing efficiency and stability of hysteresis-free inverted mesoporous perovskite solar cells

For developing inverted mesoporous perovskite solar cells and the future design of tandem devices, a p-type metal oxide with high surface area and good charge carrier mobility is of paramount importance. Here, we develop a bilayer structure of p-type Cu:NiOxnanoparticle-based mesoporous and Cu-doped NiOxblocking layers to achieve efficient charge collection at the NiOx/perovskite interface with minimized recombination loss. Our strategy enables the fabrication of centimeter-sized perovskite solar cells with a decent efficiency of 18.1%, significantly improved stability, and negligible hysteresis. The rational design of the p-type Cu-doped metal oxide bilayer provides an effective strategy for future development of inverted architecture based mesoporous solar cells.