Interface engineering by using TiO2 nanocubic modifier in planar heterojunction perovskite solar cells

In this work we adopt a nanoscale TiO2 nanocubic particle as interfacial modifier between compact TiO2 layer and CH3NH3PbI3 layer. The TiO2 nanocubic modifier can passivate the defect states and suppress charge recombination at the TiO2/MAPbI(3) interface. As a result, the photovoltaic performances of planar heterojunction perovskite solar cells were effectively boosted. Under standard air-mass 1.5 global illumination, the open-circuit voltage of solar cells with TiO2 nanocubic modifier was increased from 0.93 V to 1.02 V, and achieved a maximum power conversion efficiency of 14.70% with average value of 13.36%, which is 1.3 times higher than the solar cells based on without modified TiO2 layer (10.44%).