Low-temperature ZnO films as electron transporting layers for perovskite-based solar cells

In this study, a low-temperature sol-gel deposited ZnO thin film was used as the electron-transport layer in planar type CH₃NH₃PM₃ perovskite-based solar cells. The CH₃NH₃PM₃ films was prepared via a two-step spin-coating method and the relationship of the concentration of methylammonium iodide (CH₃NHI) was discussed. Devices fabricated based on the ZnO coated on glass and with flexible substrates are discussed. The results show that we can achieve a record efficiency of 13.5% (glass) and 10.2% (PET) under AM1.5G irradiation for the low-temperature prepared ZnO based planar type perovskite solar cell.