High-Efficiency Fiber-Shaped Perovskite Solar Cells with TiO 2 /SnO 2 Double-Electron Transport Layer Materials

The electron transport layer (ETL) of fiber perovskite solar cells ( f PSCs) is involved in transporting electrons and blocking holes. In this work, we added a SnO 2 film on the TiO 2 surface to form a double-layered TiO 2 /SnO 2 ETL to improve electron mobility and device performance. The resulting double ETL results in more uniform surface morphology and the pores in the perovskite film are greatly reduced, which increases the size of perovskite crystal particles. The resulting power conversion efficiency (PCE) increased from 2.46% to 3.81% on adding the SnO 2 layer to TiO 2 , resulting in a 54.8% improvement. Thus, this double-layered ETL structure facilitates the development of smart textiles woven from f PSCs for portable electronics.