Tin oxide nanosheets as efficient electron transporting materials for perovskite solar cells

Organolead halide perovskite solar cells with mesoporous metal oxide films as support layers have made great achievements in the field of solar cells in recent years. Here, tin oxide (SnO2) nanosheets are prepared by hydrothermal method. The as-synthesized SnO2 nanosheet layer is used as electron-transporting material to replace traditional TiO2 mesoporous layer in perovskite solar cells. The crystallizing time of CH3NH3PbI3 on SnO2 is investigated and optimized as 10 min. The surface of SnO2 nanosheets is treated with TiCl4 aqueous solution, which improves the photovoltaic performance of the perovskite solar cells. The SnO2 nanosheet-based perovskite solar cell achieves excellent photovoltaic parameters: short-circuit current density of 17.58 mA cm−2, open-circuit voltage of 1.01 V, and power conversion efficiency of 7.81%.