Production method for CdSeS and CdSeS/ZnS core-shell type quantum point

Abstract

The present invention discloses a method for preparing CdSeS and CdSeS / ZnS core-shell quantum dots, belonging to the semiconductor nanometer luminescent material technical field. The method is to dissolves Cd0 or Cd salt with a long chain fatty acid to obtain a precursor solution of Cd; a Se powder and a S powder are respectively dissolved in liquid paraffin to form a precursor mixed solution of Se and S after mixing; the precursor solution of Cd is reacted with the precursor mixed solution of Se and S to give a CdSeS quantum dot solution; Zn salt is used as a precursor of Zn for incrustation, (TMS)2S is selected as a precursor of S for incrustation, and thus a ZnS shell precursor solution is obtained, which is reacted with the CdSeS quantum dot solution to give a CdSeS / ZnS quantum dot solution; the quantum dot solution is purified to obtain the CdSeS and CdSeS / ZnS core-shell quantum dots. The fluorescence quanta is high in yield, uniform in size distribution, and good in stability, and can be applied to creature tags, illuminator members and quantum dot lasers.

Description

technical field [0001] The invention relates to a preparation method in the technical field of semiconductor materials, in particular to a preparation method of CdSeS and CdSeS / ZnS core-shell quantum dots. Background technique [0002] Quantum dots are semiconductor nanoparticles composed of II-VI and III-V elements with a diameter of 1-10nm. Since their radius is smaller than or close to the excitonic Bohr radius, they can receive excitation light and generate fluorescence, and Compared with traditional fluorescent dye molecules, there are many advantages: the fluorescence emission wavelength can be adjusted by changing the size of quantum dots, so quantum dots of different sizes can be excited by a single wavelength of light to emit different colors of fluorescence, and has a high Fluorescence quantum yield, molar extinction coefficient, narrow and symmetrical fluorescence emission spectrum, large Stokes shift between excitation and emission spectra, and strong resistance ...

AI Technical Summary

Problems solved by technology

In practice, the applied quantum dots must have good luminescent properties, but so far, the performance of the synthesized binary quantum dots in the blue light region is not ideal

CdSe quantum dots whose fluorescence emission wavelength is in the blue light region have poor fluorescence performance due to their small grain size; while CdS and ZnSe quantum dots have strong luminescence performance in the blue light region, but in practical applications, the fluorescence performance is limited. poor stability

Moreover, since the optical properties of binary quantum dots can only be adjusted by the size of quantum dot grains, the difference in the size of quantum dot grains has become a disadvantage of its application to a certain extent. It can be seen that binary quantum dots have become gradually Does not meet the requirements of practical applications

[0003] Find that Swafford published "Homogeneously alloyed CdSeS nanocrystals: synthesis, characterization, and composition / size- dependent band gap"("homogeneous structure alloy quantum dot CdS x Se 1-x The preparation, characterization and calculation of forbidden band) papers, one-step synthesis of CdS with different fluorescence emission wavelengths in ODE (octadecene) with a purity of 90% x Se 1-x Ternary quantum dots, this kind of ternary alloy quantum dots can change the fluorescence emission wavelength of quantum dots by adjusting the composition ratio of Se and S under the condition that the particle size remains unchanged, so that the obtained quantum dots have adjustable size. properties and adjustable components, and has high quantum yield and good stability, but this method still uses expensive and toxic ODE and TBP (tributylphosphine) as reaction solvent and ligand, Moreover, the synthesis temperature is high (300°C), and the synthesis process needs to be carried out under the protection of nitrogen, which limits the large-scale preparation of quantum dots of this alloy.

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