Preparation And Optical Properties Of Layered Perovskites Materials

Organic inorganic hybrid perovskites are a new kind of material which consist of organic and inorganic components through self-assemble.Organic inorganic hybrid perovskites combine distinct properties of organic and inorganic components within a single molecular composite.The inorganic components constitute the octahedral frameworks by covalent bonds or ionic bonds,which provides good conductivity,electroluminescence and dielectric transition.The organic components facilitate the self-assembly and high photoluminescence quantum efficiency.These properties can be easily controlled by changing the organic ammonium,inorganic metal or halide,which makes them great candidates for applications in solar cells,electroluminescent devices and radiation detection.The development history,crystal structures,optical properties,synthesis methods and important applications of organic inorganic hybrid perovskites are summaried systematically in this manuscript.On the basis of the research at home and abroad,the investigations on organic inorganic hybrid perovskites have been carried out theoretically and experimentally.The main contents are as followed:（1）The structures and optical properties of three perovskites which contain different halogen are prepared and investigated.The perovskite（C₆H₅CH₂NH₃）₂Pb Cl₄、（C₆H₅CH₂NH₃）₂Pb Br₄ and（C₆H₅CH₂NH₃）₂Pb I₄ are prepared by solvent evaporation in the experiment.X Ray Diffraction,Transmission Electron Microscopy,Ultraviolet Visible spectrometer,photoluminescence spectrometer and optical confocal microscopy test system are used to investigate the crystal structures,morphology and optical properties.The results show that the three perovskites are well crystallized and oriented,but there are the differences in order-disorder behavior of the organic ammonium cations.The absorption peaks of three perovskites are located at 346nm,392nm,516nm,and PL peaks of Br-based and I-based perovskite are located at 415nm and 540nm.The PL intensity increases with increasing laser power,but the lifetime decreases with increasing laser power,which is attributed to the non-geminate recombination.（2）The structures and optical properties of two perovskites which contain different organic component are prepared and studied.The perovskites（C₄H₉NH₃）₂Pb Br₄ and（C₆H₅CH₂NH₃）₂Pb Br₄ are prepared by solvent evaporation in the experiment.X Ray Diffraction,Transmission Electron Microscopy,Ultraviolet Visible spectrometer,photoluminescence spectrometer and optical confocal microscopy test system are used to investigate the crystal structures,morphology and optical properties.The results show that the two perovskites are well crystallized,and the molecular layers prefer arrangement in specific direction.The absorption peaks of two perovskites are located at416 nm and 392nm,and PL peaks of two perovskites are located at 427nm and 415nm.The PL intensity increases with increasing laser power,but the lifetime decreases with increasing laser power,which is attributed to the non-geminate recombination.