研究了聚乙烯吡络烷酮( PVP) 作为添加剂对CH3NH3PbI3钙钛矿基太阳能电池光电性能的影响。通过SEM、XRD和UV-Vis等手段, 研究了不同浓度PVP掺杂CH3NH3PbI3钙钛矿前驱体对薄膜的表面形貌、结晶度和光学性能的影响。结果表明, 少量的PVP添加可以调控钙钛矿薄膜的质量, 添加了PVP的钙钛矿薄膜的吸收性能明显得到提高, 且吸收峰红移了20 nm; 同时, 不仅增加了CH3NH3PbI3的结晶度, 而且还明显提高了钙钛矿薄膜的覆盖率, 减少了钙钛矿薄膜中的针孔结构。在CH3NH3PbI3前驱体溶液中添加质量分数为1%的PVP, 得到的钙钛矿太阳能电池的能量转换效率达到8.38%。与未加PVP 的标准电池器件效率(1.30%)相比, 效率提高了544%。这些结果表明, 通过添加剂来调控一步法CH3NH3PbI3的晶体生长和薄膜形貌来获取高性能的钙钛矿太阳能电池是很有前途的。

We demonstrate a new one-step solution approach to prepare perovskite CH3NH3PbI3 films by adding polyvinylpyrrolidone (PVP) to the standard CH3NH3PbI3 precursor solution. The film morphologies, crystallinities, and optical properties of CH3NH3PbI3 perovskite layers are carefully studied by SEM, XRD, and UV-Vis. The results reveal that the perovskite film properties can be manipulated by incorporating a small amount of PVP. The absorbance of the film with PVP additive is significantly higher than the pristine film and the absorption peak is red shift by 20 nm, indicating the perovskite film with additive possessing better crystal structures. The use of PVP strongly affects the crystallization process of forming pure CH3NH3PbI3 and helps the formation of smooth film, leading not only to enhanced crystallization of CH3NH3PbI3 but also to significantly improved coverage of CH3NH3PbI3 on a planar substrate. The optimized power conversion efficiency (PCE) of CH3NH3PbI3 solar cells improved from 1.30% to 8.38% for the planar cell structure after the addition of 1% mass fraction of PVP. These results suggest that this new one-step solution approach is promising for controlling CH3NH3PbI3 growth to achieve high-performance perovskite solar cells.