Organic-inorganic hybrid perovskite solar cells(PSCs) were first reported in 2009. After ten years of development, the certification efficiency of PSCs has reached 25.5%. The electron transport layers is the key part of the PSCs, which can block the holes and transfer electrons to reduce the recombination. Compared with TiO2, which was the most widely used electron transport layer, SnO2 has the advantages of higher electron mobility, and energy level matching with other parts of the solar cell devices, etc. Furthermore, SnO2 is a semiconductor with large energy gap, and shows little degradation under light, which is beneficial for its stability. Meanwhile, the preparation process for SnO2 based electron layer is simple and needs no high temperature sintering. In 2015, the device using SnO2 as the electron transport layer was reported for the first time, and the photoelectric conversion efficiency reached 17.21%. Subsequently, many research groups also reported high-performance PSCs based on SnO2 electron transport layer. At present, the planar PSCs with SnO2 as the electron transport layer shows a photoelectric conversion efficiency as high as 25.2%. The main problem for applying SnO2 based electron transport layer is that when SnO2 is calcined at high temperature, the crystal grains will become larger, and generates cracks in the film owing to the expansion of grain. Additional, compared with perovskite, the conduction band of SnO2 is much lower, which may cause the voltage loss of PSCs. This article systematically reviews the development of SnO2-based perovskite cells in recent years, and summarizes the effects of the preparation methods, the doping of the electron transportation layer and interface passivation on the performance. Furthermore, research trends of SnO2 based PSCs are prospected for hoping to provide a reference for the preparation of high performance PSCs. © 2022, Materials Review Magazine. All right reserved.
