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Green preparation method of cadmium selenide quantum dots with specific sizes

A specific size, cadmium selenide technology, applied in chemical instruments and methods, binary selenium/tellurium compounds, metal selenide/telluride, etc. Passivation of surface defects, reproducible, cost-effective results

Inactive Publication Date: 2020-01-07
DALIAN NATIONALITIES UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in the prior art, the method for regulating the size of quantum dots is complicated, and there are few reports on specific sizes.

Method used

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  • Green preparation method of cadmium selenide quantum dots with specific sizes
  • Green preparation method of cadmium selenide quantum dots with specific sizes
  • Green preparation method of cadmium selenide quantum dots with specific sizes

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] Example 1: Preparation of 3.6nm CdSe quantum dots.

[0027] The preparation steps are as follows:

[0028] (1) Weigh 1.284g (10mmol) of cadmium oxide, measure 15ml of oleic acid, measure 10ml of liquid paraffin, put it into a 250ml three-neck flask, feed nitrogen for 30 minutes to exhaust the air, heat and stir to 150°C under nitrogen atmosphere, After the cadmium oxide is completely dissolved, light yellow transparent cadmium oleate is generated, which is used as a cadmium precursor solution for subsequent use;

[0029] (2) Weigh 0.079g (1mmol) of selenium powder, measure 50ml of liquid paraffin, put it into another three-neck flask, pass in nitrogen for 30 minutes to exhaust the air, heat and stir to 220°C under nitrogen atmosphere, and wait for the selenium powder to completely dissolve , to generate a transparent bright orange selenium precursor solution;

[0030] (3) Measure 10ml of oleylamine and add it to the resulting selenium precursor solution, and then add ...

Embodiment 2

[0035] Example 2: Preparation of 3.1nm CdSe quantum dots.

[0036] The method is the same as in Example 1, except that the amount of cadmium precursor added in step (3) is 10ml, the molar ratio of cadmium and selenium in the solution is 4:1, and the holding time is 1 minute.

[0037] The prepared cadmium selenide quantum dots showed green fluorescence under the irradiation of 365nm ultraviolet lamp. Such as image 3 As shown, it is measured that the absorption peak in the ultraviolet-visible region is at 551nm, and when excited with 405nm excitation light, the fluorescence emission peak is at 578nm.

[0038] According to E.Valcheva et al. / Colloids and Surfaces A:Physicochem.Eng.Aspects 461, (2014), the cadmium selenide quantum dot size empirical estimation formula given in 158-166, by the prepared cadmium selenide The size of the quantum dot is estimated to be 3.1 nm from the position of the absorption peak, and the size is estimated to be 3.1 nm from the position of the flu...

Embodiment 3

[0039] Example 3: Preparation of 4.2nm CdSe quantum dots.

[0040] The method is the same as that in Example 1, except that the amount of cadmium precursor added in step (3) is 2.5ml. At this time, the molar ratio of cadmium and selenium in the solution is 1:1, and the holding time is 10 minutes.

[0041]The prepared cadmium selenide quantum dots exhibit orange fluorescence under the irradiation of 365nm ultraviolet lamp. Such as Figure 4 As shown, the absorption peak in the ultraviolet-visible region is measured at 591nm, and the fluorescence emission peak is at 613nm when excited with 405nm excitation light.

[0042] According to E.Valcheva et al. / Colloids and Surfaces A:Physicochem.Eng.Aspects 461, (2014), the cadmium selenide quantum dot size empirical estimation formula given in 158-166, by the prepared cadmium selenide The size of the quantum dot is estimated to be 4.2nm from the position of the absorption peak, and the size is estimated to be 4.2nm from the position ...

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Abstract

The invention discloses a green preparation method of cadmium selenide quantum dots with specific sizes, and belongs to the technical field of quantum dot synthesis methods. The preparation method comprises the following steps: firstly, stirring and heating cadmium oxide, oleic acid and liquid paraffin to obtain a cadmium precursor solution, then stirring and heating selenium powder and liquid paraffin to obtain a selenium precursor solution, and finally, mixing, separating and purifying the selenium precursor solution and the cadmium precursor solution according to a molar ratio to obtain a final product. The cadmium selenide quantum dots are synthesized through an oleic acid / liquid paraffin system, synthesis raw materials are economical and low in cost, operation is easy, environment friendliness is achieved, repeatability is high, and the growth process is easy to control; introduced surfactant oleylamine not only can obtain large-size quantum dots in a short time, but also can effectively passivate surface defects of the quantum dots; meanwhile, the synthesized cadmium selenide quantum dot with the specific size is relatively good in fluorescence property, and a certain preparation basis is provided for subsequent application of the cadmium selenide quantum dot.

Description

technical field [0001] The invention belongs to the technical field of synthesis methods of quantum dots, and in particular relates to a green preparation method of cadmium selenide quantum dots with a specific size. Background technique [0002] Cadmium selenide (CdSe) quantum dots are a kind of semiconductor nano-fluorescent material. Compared with the corresponding bulk materials, they have special quantum effects, good photostability, long fluorescence lifetime, and good biocompatibility. It is favored by people in many fields such as optoelectronic devices and biomedicine. [0003] The organometallic preparation method of cadmium selenide quantum dots is first reported by Bawendi et al. Trioctylphosphine oxide (TOPO) and tri-n-octylphosphine (TOP) are used as surfactants, and group II-IV semiconductor quantum dots such as CdSe and CdS are synthesized in the absence of oxygen, water and high temperature (T=300°C). These materials are costly, highly toxic, and the prepa...

Claims

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Application Information

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IPC IPC(8): C09K11/88C01B19/04B82Y20/00B82Y40/00
CPCC09K11/883C01B19/007B82Y20/00B82Y40/00C01P2004/64
Inventor 王利马楚芳陆峥林翔赵海燕
Owner DALIAN NATIONALITIES UNIVERSITY
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