Optoelectronic Properties Of Quasi Two-Dimensional Perovskite （PEA）₂（MA）_n-1Pb_nI_3n+1 And Applications Of Lateral Photodetectors

With the development of lightweight,flexible and intelligent electronic products,especially the rapid development of printed electronics and wearable electronics,two-dimensional organic-inorganic hybrid perovskites have excellent optical and electrical properties and possess inorganic materials.The self-assembly,film-forming properties,and low temperature,low cost,and easy processing of organic materials can be realized in the field of optoelectronic devices,and can be widely used due to their flexibility.At present,there are many researches on the photoelectric properties of these materials,but there are few researches on planar photodetectors.The new properties and phenomena brought by the two-dimensional perovskite through the adjustment of inorganic layers and the research on the lateral photodetectors are of great significance.This dissertation focuses on the photoelectric properties of two-dimensional perovskite and the application of lateral photodetectors.The main contents include three parts:（1）A one-step solution deposition method was used to prepare a two-dimensional three-dimensional perovskite film having the formula（PEA）₂（MA）_n-1Pb_nI_3n+1,where n is 1,3,5,10 and ∞.Through SEM,XRD,UV-visible absorption,Fluorescence Spectrum,Time-Resolved Photoluminescence Spectrum and other characterization methods to study it.The results show that the two-dimensional and three-dimensional perovskite is a multi-phase system and is a multi-quantum well structure.Within its multiphase system,electrons move from the small n-phase to the large n-phase.（2）A two-dimensional perovskite film with different thickness was prepared by one-step solution deposition method by adjusting the concentration.The chemical formula was（PEA）₂PbI₄.The film thicknesses were 54 nm,132 nm,151 nm,259 nm,635 um,and 1000 nm,respectively.SEM,XRD,UV-Vis absorption,Fluorescence Spectrum,Time-Resolved Photoluminescence Spectrum and other characterization methods were used to study the characteristics of the film.The results show that the quality of the two-dimensional perovskite film is best when the thickness is 259 nm,and the crystal orientation is the best.（3）A two-dimensional perovskite（PEA）₂PbI₄ thin film was used as a photosensitive layer and applied to a lateral photodetector to develop a high-performance photodetector with a fast response speed,a wide detection wavelength range,and high sensitivity under weak light.The normalized detection rate is as high as 1.83×10¹³ cm·Hz^1/2W^-1.Our results show that two-dimensional layered perovskite（PEA）₂PbI₄ materials have great application prospects in the field of photodetectors.