Preparation And Properties Study Of Novel Perovskite Solar Cells With High Stability

Organic-inorganic halide perovskite has sparked enormous research attention in the past few years since it features diverse advantages involving high absorption coefficient,low-temperature solution processibility,excellent carrier mobility,tunable direct energy band,and low exciton binding energy.The researchers improve the quality of perovskite film,promote interface charge transmission,and improve the photoelectronic property by solvent engineering,interface engineering,additive engineering or component engineering.Thanks to this promising material,perovskite solar cells(PSCs)have made tremendous progress,as evidenced by the rapidly rising power conversion efficiency(PCE)from the initial value of 3% in 2009 to the certified record of 25.5%.However,PSCs still have to adjust the carrier recombination to increase PCE,and PSCs are currently not commercialized due to their stability.Therefore,a lot of work is still needed to improve the photoelectric property and stability of PSCs.The main work of this paper includes the following two aspects:1:The fumaric acid(FMAC) is added into the perovskite precursor solution,using its acidic and organic functional group to change the size of the colloidal particle in the precursor solution,to regulate crystallization process.Thus we obtain pervoskite film with higher crystallization and less crystalline boundary.At the same time,there is a strong interaction between FMAC and the perovskite lattice,which enables FMAC not only to stabilize the octagon frame of the perovskite crystal,greatly blunting defects,but also to interlink the grains,which facilitates the carrier transport.As a result,we increased the PCE from 19.18% to 20.48%.FMAC also enhances the stability of PSCs,after aging in dry air for 400 h the devices with FMAC retain 83% of the initial PCE,whereas for the control devices,the PCE dropped 33%.This work provides a simple and effective strategy,that we add food-grade FMAC as additive to the perovskite precursor solution,which improves photoelectric property and stability of PSCs,and will further accelerate the development of high-efficiency PSCs.2:We fabricate a simpler FA_0.92Cs_{0 08}PbI₃ PSCs,by changing the composition of perovskite materials.The device not only had better stability,but also attains higher PCE of 21.7%.Then we evaporate polyvinylidene fluoride(PVDF)film on the back of PSCs as a protective layer,and fabricate devices with the structure FTO/TiO₂/FACs/Sprio-OMe TAD/Au/PVDF.Improving the stability of the device through the hydrophobicity of the polymer.After aging at 25? and RH=35?50% for 1000 h,the PCE of the control devices retain 80% of the initial PCE,whereas for the devices with PVDF,the PCE stay the same upon aging,higher than that of the standard sample device.Then,on this basis,we found a more appropriate polymer material PX as the protective layer of PSCs,which can improve the stability of PSCs to a greater extent.This work provides a very simple and effective strategy to improve the stability of PSCs and promotes the process of industrialization of PSCs.