The Study On The Performances Of Planar Perovskite Solar Cells With ZnO As Electron Transport Layer

The perovskite solar cells have received extensive attention in recent year due to the advantage of their excellent optoelectronic properties and easy fabrication process.The power conversion efficiency of the organic–inorganic hybrid halide perovskite solar cells rapidly raised from the initial 3.8%to the highest certified 25.5%,close to the silicon-based solar cells,which makes it a potential candidate for the next generation of photovoltaic system.However,due to the existence of volatile organic compounds in the organic-inorganic hybrid perovskite materials,it is unstable under humid and high temperature conditions.Inorganic perovskite materials with the superior thermal stability are demonstrated as an ideal choice for photovoltaic applications.The electron transport layer plays an crucial role in perovskite solar cells with the function of electron transport and hole blocking.Zinc oxide is an ideal electron transport material for its suitable energy level and high electron mobility.In this thesis,planar heterojunction organic–inorganic hybrid perovskite solar cells and inorganic perovskite solar cells with ZnO as electron transport layer were fabricated,and the research contents are as the following two aspects.(1)The localized surface plasmon resonance materials Au@Ag@SiO₂ core-shell nanocuboids are embedded into the two-step method prepared perovskite film of the organic–inorganic hybrid halide perovskite solar cells for promoting the device performances.The introduction of Au@Ag@SiO₂ effectively improved the perovskite film morphology and the device'ability of optical absorption and charge separation,dramatically increasing the power conversion efficiency and short-circuit photocurrent density.Compared to the control device,the average efficiency and short-circuit photocurrent density of the optimized device increase by about 11.10%and 7.12%,respectively.This method provides a new and promising optical engineering strategy to improve the performances of perovskite solar cells.(2)Low-temperature processed CsPbI₃ inorganic perovskite solar cells with ZnO as electron transport layer were fabricated.The phenomenon that the?-CsPbI₃ formation transition temperature decrease on ZnO surface was observed and studied.A lattices matching,low interfacial energy and nonexistent deprotonation interface can form between ZnO and CsPbI₃ interface,thus reduce the formation energy of the CsPbI₃ and enable enhance the electrical property of devices.The devices with high open circuit voltage were obtained for the favorable surface connection and the suitable energy level alignment between ZnO and the perovskite layer.These results provide a strategy to prepare the CsPbI₃ film at a low temperature and indicate the potential of ZnO as a promising electron transport material in inorganic perovskite solar cells.