An international research team has proposed using a thin aluminum oxide (AlOx) buffer layer in inverted perovskite solar cells to improve efficiency and operational stability. The layer, deposited via atomic layer deposition (ALD), sits between the electron transport layer (ETL) and the contact, allowing efficient charge-carrier extraction across the interface. The optimized AlOx layer performed similarly to a conventional 20 nm SnOx layer, achieving high power conversion efficiencies in both semi-transparent perovskite cells and perovskite-silicon tandem devices. The use of thin AlOx as a sputter-resistant buffer layer offers advantages such as a dense and uniform ALD process, lower material consumption, and faster fabrication of future perovskite devices. Researchers from various institutions including Stuttgart, Forschungszentrum Jülich, Solarlab Aiko Europe, and Portugal's INL contributed to the study and plan to conduct follow-up studies based on the research findings.