Method for improving fluorescence yield and stability of bi-based perovskite nano material and product

Abstract

The invention discloses a method for improving the fluorescence yield and the stability of a bi-based perovskite nano material and a product. The method comprises the following steps: introducing long chain amine and a chloride source into a precursor raw material required by preparation of a quantum dot MA3Bi2Br9, and by regulating and controlling the adding ratios of the long chain amine and the chloride source which are introduced, finally obtaining a product shaped like (MAxOLA1-x)3Bi2ClyBr9-y. According to the method, under the intercalation action of the long chain amine, the shape and the appearance of the product can be changed from the quantum dot into a nano sheet, so that the stronger exciton confinement effect is achieved, and the fluorescence quantum yield can be increased; by the use of the high bond energy of a bismuth-chloride bond, the stability of the quantum dot MA3Bi2Br9 is improved, and surface defects are passivated, therefore, the fluorescence quantum yield of the final product is increased. After the improvement on constituents and the structure of the quantum dot MA3Bi2Br9, compared with the prior art, the method has the advantage of effectively improving the fluorescence yield and the stability of the bi-based perovskite nano material.

Description

technical field [0001] The invention belongs to the field of photoelectric material preparation, in particular to a method and product for improving the fluorescence yield and stability of bismuth-based perovskite nanomaterials. Background technique [0002] As a new generation of light-emitting semiconductor materials, perovskite nanomaterials not only have a simple preparation method (it can be obtained by solution processing at low temperature), but also have excellent optical properties such as high quantum yield, narrow half-peak width, and adjustable emission wavelength. The field of LED lighting and display shows great application value. [0003] In order to solve the stability and toxicity problems of this material, in recent years, the research on perovskite based on new non-toxic elements (such as Sn, Bi, Ge, etc.) has attracted more and more attention. However, due to factors such as high defect density or poor stability of bulk materials, the fluorescence proper...

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Problems solved by technology

However, due to factors such as high defect density or poor stability of bulk materials, the fluorescence properties of the obtained nanomaterials are poor.

Currently reported Bi-based perovskite quantum dots (MA 3 Bi 2 Br 9 ) has a quantum yield of 4% to 12%; CsSnX synthesized by Tom C.Jellicoe et al. 3 The highest yield of quantum dots is only 0.14%; Deng Zhengtao's research group used tetravalent Sn to prepare Cs with different morphologies 2 SnI 6 Nanoparticles, but their fluorescence yields are all below 1% (0.48% for quantum dots, 0.11% for nanorods, 0.08% for nanowires, 0.054% for nanobelts, and 0.046% for nanosheets), which is far from the high-yield fluorescence required for QLED devices. Performance conditions are still far from

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