中文摘要：

钙钛矿薄膜的制备条件和生长过程对其太阳电池性能有着至关重要的影响。基于两步旋涂法,采用4种不同的薄膜工艺制备了平面异质结型钙钛矿太阳电池,系统地研究了CH3NH3PbI3薄膜形貌对于太阳电池性能的影响。实验发现,PbI2溶液的溶剂成分以及CH3NH3I溶液的浓度对于生成的CH3NH3PbI3光活性层形貌和太阳电池性能有着显著影响。相比于纯的N,N-二甲基甲酰胺（DMF）,采用DMF/二甲基亚砜（DMSO）的混合溶剂配制PbI2溶液,获得的钙钛矿薄膜层更加平整致密,器件性能更高且性能的重现性更好。通过制备条件的优化,得到了14.2%的最佳能量转换效率。此外还分析了器件伏-安（J-V）特性测量中出现的回滞现象及其可能原因,并发现在空穴层传输层和金电极间插入6nm MoO3层能够显著地抑制J-V回滞效应。

英文摘要：

Controlling of film deposition and growth is critical to photovoltaic performance of perovskite solar cells.In this work,four kinds of two-step spin-coating processes were utilized for the preparation of planar heterojunction perovskite solar cells.The effect of the morphology of CH3NH3PbI3 on the performance of the solar cells was studied systemically.It is shown that solvent types of PbI2 solution and the concentration of CH3NH3 I solution have significant impacts on morphology of the CH3NH3PbI3 active layers as well as the performance of the solar cells.The PbI2 solutions using the mixture solvent of N,N-dimethylformamide（DMF）and dimethylsulfoxide（DMSO）,compared with those in DMF,enable extraordinarily compact and flat CH3NH3PbI3 films as well as higher photovoltaic performance and better performance reproducibility.Maximum power conversion efficiency of 14.2% has been achieved by optimizing the film processing.Furthermore,the possible origin for the J-Vcurve hysteresis on the devices was proposed.It is found that the introduction of a 6nm MoO3 layer between the hole transport layer and the Au electrode significantly suppresses such hysteresis effect.