Scalable fabrication of CuOx/NiOx composite hole transport layer via a sequential magnetron sputtering method for efficient and stable perovskite solar cells

Magnetron sputtering inorganic NiO x hole transport layer (HTL) has become a practical method in the industrial production of perovskite solar cells (PSCs), owing to its advantages of large-area fabrication and high process controllability. However, the relatively poor conductivity and high defect density of HTL hinder further improvements in device performance. In this work, to address the above issues of sputtered NiO x , the composite HTL of CuO x /NiO x was innovatively deposited by sequential sputtering of Cu and NiO targets with the easy industrial production. Subsequently, through the optimization of the sputtering process parameters (time, atmosphere, and annealing temperature), the composite HTL demonstrated superior photoelectric performance compared to the single NiO x . Meanwhile, the introduction of CuO x effectively reduced the defect density of the PSCs, thereby improving the carrier transport dynamics. Finally, this viable industrialization strategy boosted the PCE of MA 0.85 FA 0.15 PbI 3 PSCs from 15.3 % to 17.86 %, which was prepared without spin-coating fragile self-assembled monolayers (SAMs) under open-air conditions, demonstrating promising potential for commercial applications.