Core-shell quantum dot and preparation method thereof

A technology of core-shell quantum dots and nuclear quantum, which is applied in the field of core-shell quantum dots and its preparation, can solve the problems of quantum dot fluorescence efficiency and stability reduction, lattice strain, and shell lattice faults, etc. The effect of good monodispersity, uniform composition and few influencing factors

Active Publication Date: 2020-04-03
NANJING TECH CORP LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

In addition, during the epitaxial growth process, the lattice mismatch will lead to lattice strain, the formation of defect states at the core-shell interface or the shell layer, and lattice faults in the shell layer, which will reduce the fluorescence efficiency and stability of quantum dots.

Method used

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  • Core-shell quantum dot and preparation method thereof

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[0031] The present invention also provides a method for preparing core-shell quantum dots, including the following steps:

[0032] S1, providing CdSe nuclear quantum dots; it should be noted that the preparation of CdSe nuclear quantum dots can be any method in the prior art, and after the reaction is purified and dissolved in a solvent, CdSe nuclear quantum dots are obtained;

[0033] S2, adding the CdSe nuclear quantum dots to the first zinc precursor solution, and then adding the mixed solution of the first cadmium precursor and the first selenium precursor, so as to coat the CdSe nuclear quantum dots with Cd x Zn (1-x) Se shell, 0

[0034] Or S2, adding the above CdSe nuclear quantum dots to the mixed solution of the first zinc precursor and the first cadmium precursor, and then adding the first selenium precursor solution, so as to coat the CdSe nuclear quantum dots with Cd x Zn (1-x) Se shell, 0

[0035] In some embodiments, the CdSe nuclear quantum dots are added t...

Embodiment 1

[0069] Synthesis of CdSe / CdZnSe / ZnSe / CdZnS / ZnS core-shell quantum dots:

[0070] Take 4mmol zinc acetate, 4.2g oleic acid, and 10mL ODE in a 100mL three-necked flask. At 200℃, pass inert gas and exhaust for 30 minutes, and inject the purified CdSe quantum dot solution with the first exciton absorption peak absorbance of 50 , Raise the temperature to 310℃; add 1mL 0.5mmol / mL Se-TOP (first selenium precursor) and 0.5mL 0.2mmol / mL cadmium oleate (first cadmium precursor) at a rate of 5mL / h The solution, after dripping, react for 10 minutes, then inject 0.2mL 2mmol / mL Se-TBP (second selenium precursor) solution, react for 10 minutes, stop the reaction to obtain CdSe / CdZnSe / ZnSe core-shell quantum dots; bring to room temperature , Purified and dissolved in 1mL ODE.

[0071] Weigh basic zinc carbonate (0.66g, 1.2mmol), 2.8g oleic acid, 5g ODE in a 100mL three-necked flask, exhaust with inert gas for 10 minutes; raise the temperature to 280℃ to obtain a clear solution; inject and purify ...

Embodiment 2

[0073] The preparation method of this embodiment differs from embodiment 1 only in:

[0074] The dosage of the 0.2mmol / mL cadmium oleate solution of the first cadmium precursor was 2mL, and the dosage of the 0.2mmol / mL cadmium oleate solution of the second cadmium precursor was 3mL.

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Abstract

The invention discloses a core-shell quantum dot and a preparation method thereof, wherein the core-shell quantum dot comprises a CdSe core, a CdxZn(1-x)Se shell layer, a ZnSezS(1-z) shell layer, a CdyZn(1-y)S shell layer and a ZnS shell layer, wherein the CdSe core is sequentially coated with the CdxZn(1-x)Se shell layer, the ZnSezS(1-z) shell layer, the CdyZn(1-y)S shell layer and the ZnS shelllayer from inside to outside, x is more than 0 and less than 1, y is more than 0 and less than 1, and z is more than 0 and less than or equal to 1. According to the invention, the core-shell quantum dot has the layer-by-layer progressive energy level structure, is small in the lattice mismatching degree between layers, uniform in the components of the alloy shell, good in size, morphology and monodispersity, narrow in fluorescence half-peak width, high in fluorescence quantum yield, high in stability, simple in whole synthesis process, few in influence factor and good in repeatability.

Description

Technical field [0001] The invention relates to the field of quantum dot materials, in particular to a core-shell quantum dot and a preparation method thereof. Background technique [0002] Quantum dots have attracted people's attention because of their high fluorescence efficiency, narrow half-peak width, and good stability. Compared with single-component nuclear quantum dots, core-shell quantum dots have higher optical and chemical stability, and can remain stable for a long time. The surface of the nuclear quantum dots is covered with a layer of shell material, so that during the excitation process, both electrons and holes are confined in the core material or only a small part of it will delocalize to the shell. Although there are still surface defects on the surface of the shell, the probability of excitons being trapped by the surface defects is reduced. The shell isolates the excitons from the external environment, so that the luminous efficiency and fluorescence stabili...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09K11/02C09K11/88
CPCC09K11/02C09K11/883
Inventor 周健海
Owner NANJING TECH CORP LTD
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