Fabrication of 1D-Confined MAPbI ₃ in Cerium Oxide Nanotubes for Nanowire Solar Cells

CeO2 is an n-type semiconductor and an excellent candidate as an electron transport layer for perovskite solar cells. However, it is challenging to fabricate high-quality CeO2 nanotubes (NTs) to meet the specific applications. Here, we report an approach to fabricating CeO2 nanotubes (NTs) using ZnO nanowires, enabling precise control over nanotube geometry. The resulting CeO2 NTs are infiltrated with MAPbI3 to form confined MAPbI3 nanowires in the CeO2 NTs structure for nanowire-based perovskite solar cells. Devices based on the confined perovskite achieve power conversion efficiencies of 11.5% and exhibit significantly improved air stability compared to planar thin-film counterparts. These results demonstrate that CeO2 NTs can serve as an efficient electron transport layer in a protective scaffold, highlighting the improved stability in perovskite nanowire solar cells.