Preparation And Photoelectric Properties Of Perovskite Quantum Dots And MOF Composites

Perovskite quantum dots containing MAPbX₃ show great potential in the fields of illumination,display,optical inspection and solar power generation.However,in light-emitting diodes,solar cells and other applications,we need to face the problems of poor stability and low luminous efficiency.This kind of problem is usually solved by doping other ions or wrapping quantum dots into other materials.Because of its unique structure,MOFs can improve the luminous efficiency or improve the stability by making other ions grow in the frame to achieve functional combination.Therefore,the thesis first studies the basic properties of perovskite in MAPbX₃ with the change of ligand materials,and grows perovskite quantum dots in the metal organic framework,and studies the properties of perovskite quantum dots and metal organic frame composites.The specific content of the article is as follows:(1)Synthesis of organic perovskite MaPbBr₃ quantum dots.In this paper,organic perovskite MaPbBr₃ quantum dots were prepared by microemulsion method.A series of different MaPbBr₃ perovskite quantum dots were prepared by changing the content of n-octylamine(OLAM).It is found that with the increase of n-octylamine,the main luminescence peak of the as prepared organic perovskite MaPbBr₃ quantum dots gradually shifts from 530nm to 430nm,and the luminescence gradually changes from green to blue violet,and the high efficiency is gradually reduced,and the average lifetime gradually shortens.When too much n-octylamine is added,the size distribution of perovskite quantum dots becomes uneven,the surface passivation of quantum dots and the increase of defect states affect the luminescence efficiency.(2)Preparation of organic perovskite MaPbBr₃/MOFs composites.In this paper,the composite of MAPbBr₃ quantum dots and MOFs was synthesized by hydrothermal method.A series of different polymer materials have been prepared based on changing the composition of lead positive ions.Through the comparison of XRD and IR spectra of Eu-MOF,Eu-MOF-Pb precursor and MAPbBr₃-MOFs composite,it is found that MAPbBr₃-MOFs composite has the same structure as Eu-MOF and organic perovskite MaPbBr₃at the same time.Through the measurement of luminescence spectra,it is found that MAPbBr₃-MOFs composite not only has red light at 591nm and 617nm under 365nm laser excitation Therefore,the MAPbBr₃-MOFs composite can have excellent properties of both metal organic framework and perovskite quantum dots.