The Effect of Photoanode TiO2/ZnO Ratio in Perovskite Solar Cell and Its Photosensitivity and Solar Cell Performance

Abstract

Perovskite Solar Cell (PSC) CH3NH3PbI3 has attracted interest due to a high potential for cheap and high-efficiency solar cell. The PSC mainly consists of three components that are an electron transporting material (ETM), perovskite layer, and hole transport material (HTM). The ETM layer quality plays an important role for electron transport, acts as a selective collection of electron and hole blocking layers that have an important influence on photovoltaic performance. TiO2 and ZnO are the most common materials used in ETM. TiO2 has a good photo activity, high stability, and non-toxicity. Meanwhile, ZnO has good anti-reflecting properties that make electron more easy to transfer from valence band to conduction band. In this research, the formation of TiO2 and ZnO was composited as ETM to combine the advantages of both with the variations of TiO2/ZnO mass ratio. The ETM films were synthesized by screen printing methods, whereas the perovskite layer and HTM of Cu2O were coated by spin coating and chemical bath deposition (CBD) respectively. The samples were characterized by XRD and UVVis spectrometer. The photosensitivity and solar cell performance were measured by electrometer and solar simulators. The TiO2/ZnO composition of ETM showed a different efficiency and photosensitivity. The sample with higher TiO2 indicated stable photosensitivity but less in the solar cell efficiency and vice versa.