Method for preparing nano-crystal with core-shell structure

A technology of core-shell structure and nanocrystals, which is applied in the field of synthesis of high-quality core-shell structure nanocrystals by a phosphorus-free method, can solve the problems of harsh reaction conditions, complicated preparation process, and high synthesis cost, and achieve simplified synthesis procedures, simple procedures, and convenient The effect of the operation

Inactive Publication Date: 2008-09-10
王小萍
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a low-cost, simple and convenient method for synthesizing nanocrystals with a core-shell structure, which solves the problems of complicated preparation process, harsh reaction conditions and high synthesis cost

Method used

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  • Method for preparing nano-crystal with core-shell structure
  • Method for preparing nano-crystal with core-shell structure
  • Method for preparing nano-crystal with core-shell structure

Examples

Experimental program
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Embodiment 1

[0025] Synthesis of CdSe / ZnS core-shell nanocrystals. Take 0.4×10 -7 mol dot-like particles of CdSe nanocrystals (2.4nm in diameter) were injected into a 50mL three-path bottle, 3mL of liquid paraffin and 1g of octadecylamine were added, and the mixed solution was heated to 100°C under nitrogen for 30 minutes to exclude oxygen, and then heated to 140°C. ℃; heat and dissolve 1mmol ZnO and 3mmol oleic acid into 10ml liquid paraffin to obtain Zn(OA) 2 Solution, dissolve 1mmol sulfur in 10ml liquid paraffin to obtain a sulfur solution, mix 0.19ml zinc oleate and 0.19ml sulfur solution, add dropwise to a three-necked flask and raise the temperature to 160°C. After 10 minutes, add a mixed solution of 0.35ml zinc oleate solution and 0.35ml sulfur solution, raise the temperature to 200°C, and operate sequentially to obtain CdSe / ZnS nanocrystals with different thicknesses. Sampling and observation before each addition. In this process, core-shell structure nanocrystals with differen...

Embodiment 2

[0027] Synthesis of CdSe / CdS core-shell nanocrystals. Wherein, 1mmol cadmium oxide and 3mmol oleic acid are dissolved in 10ml liquid paraffin and thermally dissolved until the oleic acid cadmium solution obtained by clarification replaces the oleic acid zinc solution in the embodiment 1, and others are the same as the embodiment 1. The fluorescence absorption spectrum of CdSe / ZnS core-shell nanocrystals coated with three layers of CdS is shown in Figure 4 .

Embodiment 3

[0029] Synthesis of CdSe / CdS / ZnS core-shell nanocrystals. Take 0.21×10 -7 mol dot-like particles of CdSe nanocrystals (3.4nm in diameter) were injected into a 50mL three-path bottle, 3mL of liquid paraffin and 1g of octadecylamine were added, and the mixed solution was heated to 100°C under nitrogen for 30 minutes to exclude oxygen, and then heated to 160°C. ℃; heat and dissolve 1mmol CdO and 3mmol oleic acid into 10ml liquid paraffin to obtain Cd(OA) 2 Solution, heat and dissolve 1mmol ZnO and 3mmol oleic acid into 10ml liquid paraffin to obtain Zn(OA) 2Solution, dissolve 1mmol of sulfur in 10ml of liquid paraffin to obtain a sulfur solution, mix 0.67ml of cadmium oleate and 0.67ml of sulfur solution, add it dropwise into a three-necked flask and raise the temperature to 180°C to form a layer of CdS; After 10 minutes, add a mixed solution of 0.93ml zinc oleate solution and 0.93ml sulfur solution, raise the temperature to 200°C, and operate sequentially to obtain CdSe / CdS / Zn...

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Abstract

The invention relates to a preparation method for a core-shell structure nanocrystal, wherein a nanocrystal in the shape of a spot particle containing selenium compound is dissolved in a solvent added with an additive, then the oxygen contained in the solution is eliminated in an environment of inertia gas to obtain a solution 1, then sulfur and the precursor of 12th group of elements are respectively dissolved in solutions with the same solvent and mixed so as to obtain a solution 2, which is dripped into the solution 1, then the mixed solution is heated up to 120-280 DEG C to make the nanocrystal to grow, so as to obtain the core-shell structure nanocrystal with the nanocrystal containing the selenium compound as the core and with the sulfide as the shell; the additive is an organic amine or an organic acid, each of which contains the carbons not less than 10; and the solvent is a non-coordinate solvent with the boiling point no higher than 60 DEG C; and the molecular ratio between the sulfur and the 12th group of elements is 1:1-1.5. The invention is characterized in simplified procedures, easy operation, environment-friendly solvent, low cost which can be saved by more than 50percent, and great application value on both laboratorial and industrial synthesis.

Description

(1) Technical field [0001] The invention relates to a method for preparing nanocrystals with core-shell structure, in particular to a method for synthesizing high-quality nanocrystals with core-shell structure without phosphorus. (2) Background technology [0002] Semiconductor nanoparticles are also called semiconductor quantum dots. Due to their relatively small size, ranging from a few to a dozen nanometers, they will produce many physical and chemical properties that bulk materials do not have, such as quantum size effects and dielectric confinement effects. , surface effects, etc., making it have broad application prospects in optoelectronic devices, solar cells, and laser biomarkers. Core-shell structure nanocrystals are composite structure nanocrystals formed by coating one or more than two other materials on the basis of a single nanocrystal. A nanocrystal with a semiconductor as the core, a nanocrystal with a semiconductor with a narrow bandgap as the shell and a s...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09K11/02
Inventor 李林松申怀彬
Owner 王小萍
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