咪唑添加剂对钙钛矿太阳能电池性能的影响

Effects of imidazole additive on the performance of perovskite solar cells

为钝化钙钛矿薄膜中的缺陷并改善薄膜质量,将咪唑(Imidazole,IM)添加到钙钛矿前驱体中,并通过旋涂法制备钙钛矿薄膜;采用X射线光电子能谱仪、扫描电子显微镜、X射线衍射仪、紫外-可见分光光度计和稳态-瞬态荧光寿命光谱仪对钙钛矿薄膜形貌、结构和性能进行表征。结果表明:IM同时具有路易斯酸性与路易斯碱性,能够有效调控钙钛矿晶体生长,增大钙钛矿晶粒,改善钙钛矿薄膜质量;IM与钙钛矿中未配位的Pb2+和I-形成络合,协同钝化薄膜表面与晶界处的Pb2+和I-缺陷;经过IM修饰的电池器件,其光电转化效率从15.43%提高到17.02%;具有较大晶粒以及较低缺陷态密度的高质量钙钛矿薄膜,可以有效阻挡水分子的入侵,提高电池器件的稳定性。基于IM添加剂成功制备了低缺陷的高质量钙钛矿薄膜,为钙钛矿太阳能电池的商业化生产提供了理论指导。

To passivate the defects in perovskite films and improve the quality of the films,imidazole(IM)was added to the perovskite precursor.The perovskite films were prepared by spin-coating method.The morphology,structure and properties of the perovskite films were characterized by X-ray photoelectron spectrometer,scanning electron microscope,X-ray diffractometer,ultraviolet-visible spectrophotometer and steady-transient fluorescence lifetime spectrometer.The results show that IM is both Lewis acidic and Lewis basic,can effectively regulate the growth of perovskite crystals,increase the grain size of perovskite,and improve the quality of perovskite films.IM can also simultaneously form complexation with uncoordinated Pb2+and I-in perovskite,and collaboratively passivate Pb2+and I defects at the film surface and grain boundaries.The photoelectric conversion efficiency(PCE)of the IM-modified cell device increases from 15.43%to 17.02%.The high-quality perovskite films with large grain size and low density of defect states effectively block the invasion of water molecules and improve the stability of the battery device.The successful preparation of high quality perovskite films with low defects based on the IM additive provides theoretical guidance for the commercial production of perovskite solar cells.