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

CeO 2 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 CeO 2 nanotubes (NTs) to meet the specific applications. Here, we report an approach to fabricating CeO 2 nanotubes (NTs) using ZnO nanowires, enabling precise control over nanotube geometry. The resulting CeO 2 NTs are infiltrated with MAPbI 3 to form confined MAPbI 3 nanowires in the CeO 2 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 CeO 2 NTs can serve as an efficient electron transport layer in a protective scaffold, highlighting the improved stability in perovskite nanowire solar cells.