Abstract: The perovskite solar cells with structure of glass/FTO/compact TiO2/mesoporous TiO2/CH3NH3PbI3 film/carbon electrode were prepared, and the photovoltaic performance of solar cells was studied.The perovskite CH3NH3PbI3 layers were prepared by two-step method.First, PbI2 thin films were deposited by spin coating method.Second, to grow perovskite layers, PbI2 films were dipped into 0.044 mol/L of MAI/IPA solution for 0.5 h, 2.5 h, 3.5 h and 4.0 h, respectively.The effect of dipping time on structure and morphology of perovskite layers, as well as photovoltaic performance of perovskite solar cells were studied.The results indicate that the full conversion of PbI2 to perovskite carry out and the average grain size of CH3NH3PbI3 is the largest when dipping time is 3.5 h.The perovskite solar cells prepared at dipping time of 3.5 h exhibited an optimal photovoltaic performance, which demonstrate the open circuit voltage of 0.881 V, short-circuit current density of 22.17 mA/cm2, power conversion efficiency of 6.79;, and the efficiently of incident photons converting to the electrons (IPCE) of close to 50; in visible range.

Key words: The perovskite solar cells with structure of glass/FTO/compact TiO2/mesoporous TiO2/CH3NH3PbI3 film/carbon electrode were prepared, and the photovoltaic performance of solar cells was studied.The perovskite CH3NH3PbI3 layers were prepared by two-step method.First, PbI2 thin films were deposited by spin coating method.Second, to grow perovskite layers, PbI2 films were dipped into 0.044 mol/L of MAI/IPA solution for 0.5 h, 2.5 h, 3.5 h and 4.0 h, respectively.The effect of dipping time on structure and morphology of perovskite layers, as well as photovoltaic performance of perovskite solar cells were studied.The results indicate that the full conversion of PbI2 to perovskite carry out and the average grain size of CH3NH3PbI3 is the largest when dipping time is 3.5 h.The perovskite solar cells prepared at dipping time of 3.5 h exhibited an optimal photovoltaic performance, which demonstrate the open circuit voltage of 0.881 V, short-circuit current density of 22.17 mA/cm2, power conversion efficiency of 6.79;, and the efficiently of incident photons converting to the electrons (IPCE) of close to 50; in visible range.