Studies On Interface Materials And Film Formaton Evolution Mechanism For Perovskite Solar Cells

In this paper,the interface materials of perovskite solar cells including electron transport layer,hole transport layer,and interfacial insertion layer were prepared.The device interface characteristics and stability were optimized.The perovskite film formaton evolution and phase transiton mechanism were systematically studied.Firstly,we optimized the preparation technology to promote the application and development of tin dioxide electron transport materials for perovskite solar cells.A new type of tin dioxide electron transport material prepared by the solution method was employed in planar structure perovskite solar cell to replace traditional electron transport materials which benefiting for reducing the preparation temperature and cost.Wide band gap magnesium oxide as interface materials was introduced which can effectively suppress carrier recombination and improve device performance.We further developed tin dioxide electron transport layer based on the electron beam evaporation technology with low-temperature preparation processs which is suitable for industrialized mass production.Secondly,we pave efforts to improve the performance and environment stability of the inverted structure perovskite solar cells.A hydrophobic wide band gap inorganic protective layer（Ga₂O₃）was introduced at the metal electrode interface for the first time,which can effectively mitigate moisture and metal electrode diffusion.The heterjunction passivation strategy was proposed.The organic molecular IDIC passivation material was introduced into the perovskite film to improve the quality and stability of the perovskite film.Thirdly,our works effectively improved the stability of all-inorganic perovskite solar cells.All-inorganic perovskite suffer from the problem of the unwanted phase transition.We demonstrate an effective route to simultaneously stabilize the cubic phase and lower the fabrication temperature of perovskite solar cells with the doping of large size guanidinium cations（GA）.Spiro-OMe TAD as a common hole transport material is not suitable for all-inorganic perovskite solar cells,because the complex doping and oxidation process could cause instability of device.Organic photovoltaic polymers including J71,PBDB-T,PM6 were employed in the perovskite solar cells as hole transport layer for the first time,avoiding device instability caused by complex doping and oxidation process and improving stability and reprodictivity of the device.Lastly,the phase transition mechanism and film formation process of all-inorganic perovskite solar cells was reavealed via in-situ synchrotron radiation technology.Synchrotron-based in-situ GIWAXS technology was employed to probe the real-time evolution of perovskite microstructures,in order to undersand the role of the halide element in crystallization evolution,phase transition dynamics along with their photovoltaic performances.Our works provide an important guidance for the preparation of high quality all-inorganic perovskite films.