The Fabrication Of Efficient And Stable Perovskite Solar Cells By Modification Of Ammonium Phthalocyanine/Porphyrin

Organic-inorganic metal halide perovskite(OIHP)shows great commercialization potential because of its excellent photoelectric properties and ultralow preparation cost.The photoelectric conversion efficiency(PCE)of perovskite solar cells(PSCs)has been rapidly improved from 3.8%to 25.5%in just over a decade,which is close to the PCE of commercial silicon-based solar cells.However,the commercialization of PSCs still suffers the impede from the devices long-term stability under operation environment and the preparation of large area devices.To solve these problems,this thesis focused on the perovskite surface modification and interior doping by ammonium phthalocyanine/porphyrin macrocyclic plane conjugate molecules.Finally,the high performance and stable PSCs was prepared by passivation grain boundary and surface defects.Furthermore,we achieve the preparation of high-quality large area perovskite films,which provide a new method for industrialization mass produce of PSCs.Chapter 1.Firstly,we introduce the chemical composition and crystal structure of OIHP,and further discuss the source of the rapid increase of PCE according to the perovskite band-gap,photoelectric properties and the solar cells structure.In addition,we introduce the problem and challenges in the development of perovskite solar cells,and put forward the research significance,research ideas and research schemes of this thesis according to the reported solutions.Chapter 2.We synthesize tetra-ammonium Zinc Phthalocyanine(Zn Pc)complexe as passivator to modify the surface of perovskite films by post-treatment.Phthalocyanine is a large ring complexe of aromatic conjugated system with multiple?electrons.Phthalocyanine is a suitable defect passivator for OIHP films because of its broader light absorption,excellent charge transfer properties and excellent thermal stability.In this chapter,the more stable(Zn P_C)_0.5MA_n-1Pbn I_3n+1 two-dimensional(2D)perovskite was formed at the perovskite grain boundaries(GBs)by modifying the surface of the perovskite film by Zn Pc,which effectively suture the GBs and passivating the defects.The experimental results show that a passivation protective layer is formed at the GBs of the post-treated perovskite film,and the hydrothermal stability of the PSCs is greatly improved on the precondition of improving the PCE.Chapter 3.In order to effectively modify and stabilize the GBs in perovskite interior,Zn Pc were spin-coated on the surface of perovskite intermediate.During the annealing process of perovskite intermediates,a large number of 2D(Zn Pc)_0.5MA_n-1Pb_nI_3n+1 perovskite was formed at the GBs by Zn Pc participat in the perovskite crystal growth process.More importantly,the 2D and the 3D perovskite form a graded 2D-3D structure at the top of perovskite films,which can improvement the ability of perovskite to resist the erosion from the external environment(such as humidity and thermal)and reduce component loss to increase the stability of perovskite films.Finally,the PSCs based on Zn Pc intermediate treatment shows a great hydrothermal stability.Chapter 4.We designed and synthesized monoammonium zinc porphyrin(Zn P)complexe with better solubility and as similar structure as Zn Pc as an additive to passivating the surface and interior GBs.The experimental results show that Zn P is beneficial to charge transfer in the perovskite interior,and the PCE of corresponding PSCs were improved obviously.In addition,Zn P can regulate the perovskite crystalization and inhibit the escape of MA⁺during annealing results in the low defect density and the high-quality perovskite film.Moreover,Zn P is anchored at the GBs via ammonium group to effectively passivate the surface and internal defects,thus realize the anticipatory molecular encapsulation.Finally,the high efficiency and stable PSCs were fabricated by doping Zn P.Furthermore,based on the function of Zn P regulating perovskite crystallization,the high quality large-area perovskite films and high efficiency(>18%)large-area PSCs were fabricated by blade-coated.Our strategy provides a new development direction for the production of large-area perovskite solar cells.Chapter 5.Finally,we summarize the results of interface modification and additive doping in this thesis,and prospect the future development of perovskite solar cells.