Research On The Photophysical Properties Of CsPbX₃ Perovskite Quantun Dot

In recent years,due to their excellent properties,pure inorganic perovskite quantum dots have attracted the attention of researchers all over the world.For example,the band gap can be changed by adjusting the halogen component,and the size of the quantum dots can be changed by controlling the temperature of the synthesis.Although many years ago,the organic-inorganic hybrid quantum dots have been widely studied.Compared with pure inorganic quantum dots,organic inorganic hybrid quantum dots are unstable,and they are easy to deteriorate when they meet water and oxygen.Therefore,the pure inorganic perovskite quantum dots have also been applied in light emitting devices with excellent physical properties.Some people use it to create light-emitting diodes,photodetectors,and even use it to produce a laser.However,there is still a great deal of research on its photophysical properties.In this thesis,we present a comprehensive spectroscopic study of the time-resolved fluorescence quenching kinetics of pure inorganic perovskite quantum dots.We use ultrafast transient absorption spectroscopy and time-resolved Single photon technology carefully study the photophysical properties of pure inorganic perovskite quantum dots,and it shows the specific charge transfer process of CbPbX₃-quencher,the main contents of this article are as follows:Firstly,this article mainly introduced the research of the pure inorganic perovskite?CbPbX₃?quantum dots,and give a simple introduction about ectronic quenching agent?TCNE?and hole quencher?PTZ?properties.The second part is a detailed introduction to the technology used in our test,which is a time correlated single photon counting?TCSPC?device system,femtosecond time-resolved transient absorption spectroscopy.The third part of this thesis is to give two kinds of different halogen perovskite quantum dots,two different sizes of the sample preparation method,respectively;In addition,the characterization methods of samples are also introduced.Such as,steady-state absorption spectroscopy,fluorescence spectroscopy,transmission electron microscopy?TEM?images and X ray diffraction image.In fourth part,we compared the dynamics of CsPbBr₃ quantum dots,Cs Pb I3 quantum dots and in two sizes and CsPbX₃-quencher complexes.We conclude that the charge transfer rate of CsPbBr₃-quencher complexes is faster than that of CsPbBr₃-quencher complexes;this is due to the difference of energy level;Similarly,in term of the CsPbBr₃ quantum dots.The smaller size of the quantum dots has a faster electron transfer kinetics comparing with the large size quantum dots because of the defects of quantum dots on the surface.Generally speaking,the research on the optical properties of perovskite quantum dots can make us have a better understanding about the photoelectric properties.A more accurate calculation of the absolute level provides a theoretical basis for a very powerful in order to improve the performance of optoelectronic devices.