Magnetron sputtered Al-doped NiOx films as a hole transport layer for perovskite solar cells

NiOx is an ideal replacement material for organic hole transport layers, due to its chemical stability and low cost. However, the inherent insulating properties of NiOx films and the post-processing process of solution preparation have been limiting their application and development. Herein, high-quality AlyNi1-yOx hole transport layers were prepared by magnetron sputtering at room temperature without further processing. Simulation and experimental results showed that Al atoms enhance the concentration of holes in NiOx films, thus improving the electrical conductivity. In addition, the AlyNi1-yOx films exhibited match band alignment with perovskite films, enabling the improved charge transfer and exaction. Furthermore, the perovskite film quality was improved by the AlyNi1-yOx passivation. These factors resulted in an improvement in the power conversion efficiency of 5.4%, compared with undoped NiOx-based perovskite solar cells. This work provides a prospective reference for the high-throughput production of perovskite solar cells.