Surface Property Regulation of a Magnetron-Sputtered NiOx Hole Transport Layer for High-Performance Inverted Perovskite Solar Cells

The inverted perovskite solar cells (PSCs) are gaining increasing attention recently for their unprecedented advantages, such as better integration with tandem and flexible designs, negligible hysteresis, good operational stability, and compatibility with commercially scalable fabrication approaches. Nickel oxide (NiOx) films prepared by magnetron sputtering technology exhibit excellent scalability and reproducibility, which could well meet the requirements of the large-scale production of inverted PSCs. However, NiOx prepared by vacuum methods generally has fewer surface hydroxyl groups, deteriorating the wettability and damaging the interface contact with the perovskite. Particularly, the Ni