Embedding SnO₂ Thin Shell Protected Ag Nanowires in SnO₂ ETL to Enhance the Performance of Perovskite Solar Cells

The energy level mismatching between SnO₂ and perovskite and the nonradiative recombination at SnO₂-perovskite interface severely degrade the extraction of carriers, reducing the power conversion efficiency (PCE) and stability of planar perovskite solar cells (PSCs) based on SnO₂ electron transfer layer (ETL). In the present work, a reinforced SnO₂ ETL was successfully developed by embedding SnO₂ thin shell protected Ag nanowires (Ag/SnO₂ NWs) in traditional planar SnO₂ film, which was proved to not only lower the conduction band of SnO₂ to adjust the energy level matching, but also significantly reduce the interfacial carrier recombination. Moreover, Ag/SnO₂ NWs improved the electrical conductivity of SnO₂ ETL, and effectively promoted carrier transport. Benefiting from the use of Ag/SnO₂ NWs, our newly designed PSC achieved a significantly increased champion PCE of 19.78%, which is 7% higher than the traditional PSC without Ag/SnO₂ NWs embedding, indicating its great application potential in PSCs.