Preparation method of dimension-controllable CsPbX3 perovskite nanometer crystals

Abstract

The present invention relates to a preparation method of dimension-controllable CsPbX3 perovskite nanometer crystals, and belongs to the technical field of preparation of a semiconductor nanomaterial.The method comprises: firstly, adding a cesium carboxylate solution to a lead bromide solution in N2 protection for a reaction, thereby obtaining CsPbBr3 perovskite nanometer crystal seeds; then, dispersing CsPbBr3 perovskite nanometer crystal seeds in hexane, injecting the obtained product to octadecene at different temperature to obtain CsPbBr3 perovskite nanometer crystals with different sizes; and finally, dispersing CsPbBr3 perovskite nanometer crystals in hexane, and gradually adding a lead chloride solution or a lead iodide solution drop by drop for a reaction to obtain other CsPbX3 (X=Cl, Ir) perovskite nanometer crystals. The method is simple to operate, the size of products is easy to adjust, and the components are controllable.

Description

technical field [0001] The invention belongs to the technical field of semiconductor nanomaterial preparation, in particular to a high-quality CsPbX with controllable size 3 (X=Cl, Br, I) Synthetic method of perovskite nanocrystals. Background technique [0002] After the semiconductor material is gradually reduced from the bulk phase to a certain critical size (1-20 nanometers), the volatility of the carriers becomes significant, and the movement will be limited, resulting in an increase in kinetic energy. The corresponding electronic structure is continuous from the bulk phase to The energy level structure becomes a quasi-split discontinuity, a phenomenon known as the quantum size effect. The more common semiconductor nanoparticles, that is, quantum dots, mainly include II-VI, III-V and IV-VI groups. These types of quantum dots are well obeyed by the quantum size effect, and their properties change regularly with the size, for example, the absorption and emission wavelen...

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Problems solved by technology

However, the perovskite nanocrystals prepared by this method are hot injected at high temperature and there are a large number of unreacted inorganic salts and organic ligands, which makes the whole reaction uncontrollable. Therefore, the synthesized by this method Halogen-lead-cesium perovskite nanocrystals have a certain size distribution

When the size of the nanocrystal is not very uniform, it will show a broadening of its absorption and emission spectrum, and its absorption and emission half-peak width will increase, that is to say, the emitted fluorescence is not very pure. , which will limit the application of pure inorganic perovskite nanocrystals in display and imaging

However, the xie group can obtain a series of single-size CsPbX by adjusting the ratio of oleylamine through room temperature reaction. 3 Perovskite nanocrystals, although this kind of perovskite nanocrystals have extremely narrow emission half-peak width and fluorescence purity, but because they are synthesized at room temperature, the particle size is very small (no more than 4nm), so the particles are not very Stable, prone to self-decomposition

[0004] In summary, the existing inorganic perovskite nanocrystals have certain limitations, there are unresolved problems and defects, and the technology needs to be innovated and improved.

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