Embedding SnO 2 Thin Shell Protected Ag Nanowires in SnO 2 ETL to Enhance the Performance of Perovskite Solar Cells.

The energy level mismatching between SnO 2 and perovskite and the nonradiative recombination at SnO 2 -perovskite interface severely degrade the extraction of carriers, reducing the power conversion efficiency (PCE) and stability of planar perovskite solar cells (PSCs) based on SnO 2 electron transfer layer (ETL). In the present work, a reinforced SnO 2 ETL was successfully developed by embedding SnO 2 thin shell protected Ag nanowires (Ag/SnO 2 NWs) in traditional planar SnO 2 film, which was proved to not only lower the conduction band of SnO 2 to adjust the energy level matching, but also significantly reduce the interfacial carrier recombination. Moreover, Ag/SnO 2 NWs improved the electrical conductivity of SnO 2 ETL, and effectively promoted carrier transport. Benefiting from the use of Ag/SnO 2 NWs, our newly designed PSC achieved a significantly increased champion PCE of 19.78%, which is 7% higher than the traditional PSC without Ag/SnO 2 NWs embedding, indicating its great application potential in PSCs.