Efficient hole-conductor-free printable mesoscopic perovskite solar cells based on SnO^sub 2^ compact layer

TiO2 compact layer (c-TiO2) is generally applied for high-efficiencies perovskite solar cells (MPSCs), but it shows a relatively low electron mobility, which may restrict some performance of the MPSCs. Herein, we demonstrated SnO2 compact layer (c-SnO2), which prepared by spray pyrolysis using a solution of dibutyltin bisacetylacetonate in ethanol, could be an excellent alternative compact layer for efficient hole-conductor-free printable MPSCs. The best device with such a c-SnO2 has achieved an efficiency of 13.77%, which is very comparable to that obtained by the device based on c-TiO2. Furthermore, the device with c-SnO2 showed less pronounced hysteresis effect, probably because of the higher electron mobility of SnO2 and less charge accumulation at the interfaces. The simple preparation process and improved hysteretic behavior pave the way for industrialization of PSCs.