Surficial And Interfacial Structure Manipulation Of Perovskite Solar Cells By Porphyrin Complexes

Owing to the simple preparation process and high photoelectric conversion efficiency,perovskite solar cells have attracted wide attention and are expected to be applied in industrial application.After continuous optimization of perovskite components,device structure,preparation technology,modification control and so on,the efficiency of perovskite solar cells has increased to 25.8%.Although the efficiency of perovskite solar cells has been able to meet the commercial application,the longterm stability of perovskite solar cells still restricts their large-scale commercial application.In order to improve the efficiency of solar cells and enhance the stability of perovskite solar cells,porphyrin modifiers were rational designed and introduced into the bulk and interfacial of perovskite film to regulate the structure of perovskite,in order to reduce the defects of perovskite,improve the efficiency of perovskite solar cells and enhance the operating stability of devices.The main research work is as follows:1.The simple tetra-ammonium zinc porphyrin molecules were introduced into the perovskite layer,the stable two-dimensional perovskite structure was formed in the perovskite grain boundary,and the grain boundary suture and defect passivation were carried out on the surface of perovskite,further stabilizes the perovskite grain boundary structure,and finally significantly improves the stability of perovskite solar cells.2.In this chapter,alkyl chains are introduced in the periphery of di-ammoniumzinc porphyrin to enhance the solubility of porphyrin.Through surface treatment strategy,di-ammonium zinc porphyrin was introduced into perovskite grain boundary,the stable two-dimensional perovskite structure was formed at perovskite grain boundary,further passivate the surface defects and regulating perovskite surface.Finally,the efficiency and stability of perovskite solar cells are significantly improved.3.The strategy of perovskite surface self-encapsulation was developed based on the coordination of the porphyrin amine group with the neighboring porphyrin metal center to form a coordination polymer.The post-treatment of di-amino zinc porphyrin was introduced into the surface of perovskite,and the surface of perovskite was passivated by solvent-induced spontaneous assembly to generate two-dimensional structure,further reduced defects of perovskite film and improve efficiency and stability of perovskite solar cells.4.It is essential to further improve the performance and stability of perovskite cells by passivation of defects located at the buried surface of perovskite films.Two kinds of ammonium metalloporphyrin with solubility differences were introduced into perovskite precursor solution.During the crystallization process of perovskite,porphyrin molecules were distributed unevenly in the vertical direction of perovskite to the upper and buried surfaces of perovskite film and formed two-dimensional perovskite structure,which passivated the upper surface of perovskite and buried interface at the same time.Finally,obtained efficient and stable perovskite devices.