The Composite Structure Modulates The Luminescence Properties And Mechanism Of CsPbBr₃ Perovskite Quantum Dots

All inorganic halide perovskite QDs(QDs)CsPbX₃(X=Cl,Br,I)have many excellent photoelectric properties,such as high absorption coefficient,narrow emission spectrum,high fluorescence quantum yield and tunable luminescent color by adjusting the halide proportion or morphology of QDs.As a result,CsPbX₃ perovskite QDs have great application potential in the fields of photoelectric display,laser devices,solar cells,light-emitting diodes and even piezoelectric devices,and also attracted the attention of many researchers.However,the researches of all inorganic halide CsPbX₃ perovskite QDs mainly focuses on the synthesis methods and the application fields of optoelectronic devices at present,while the performance expansion and improvement of perovskite QDs are still relatively lacking,including the green emitting CsPbBr₃ QDs in the up conversion domain and white light emission,or the storage stability of CsPbBr₃ QDs has been improved.In this paper,the composite structure material is formed by the combination of other materials and CsPbBr₃ perovskite QDs,so as to expand and improve the properties of CsPbBr₃ QDs.The main experimental results are as follows:(1)High quality green CsPbBr₃ perovskite QDs were synthesized by the heat injection method.The QDs were characterized by Transmission Electron Microscopy,X-ray diffraction and photoluminescence spectra.The cubic CsPbBr₃ perovskite QDs with regular arrangement,good dispersion and uniform size were obtained.(2)In the first study,up conversion NaYF₄ nanoparticles with hexagonal phase were prepared by coprecipitation method.The emission spectra with blue-band and red-band were obtained by doping Tm³⁺and Yb³⁺,and then they were combined to form a composite structure.Under the mechanism of energy transfer,the photoluminescence of CsPbBr₃ perovskite QDs were realized in near infrared,and the white light emission of QDs in the up conversion field is obtained.(3)The lead precursor solution of CsPbBr₃ perovskite QDs was treated with Dodecyl mercaptan.The emission efficiency and storage stability of the QDs were improved by adjusting the concentration of the auxiliary ligands,and the QDs could be kept at room temperature for 16 days or longer.Subsequently,the properties of CsPbBr₃ perovskite QDs were further improved by UV irradiation.