Blue-green luminescent quantum dots and preparation method therefor

A technology of light-emitting quantum and quantum dots, which is applied in the fields of light-emitting materials, chemical instruments and methods, nano-optics, etc., can solve the problem of difficult to obtain blue-green light emission with quantum yield, and achieves reduction of toxicity, improvement of yield, and reduction of raw material costs. Effect

Active Publication Date: 2016-07-27
BYD CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] When preparing such quantum dots, only binary quantum dots can be obtained. When the size of this quantum dot is very small (less than 2nm), it is difficult to passivate its surface by epitaxiall

Method used

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  • Blue-green luminescent quantum dots and preparation method therefor
  • Blue-green luminescent quantum dots and preparation method therefor
  • Blue-green luminescent quantum dots and preparation method therefor

Examples

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preparation example Construction

[0025] The above-mentioned blue-green light-emitting quantum dots provided by the present invention can be produced by referring to existing conventional methods. In a preferred embodiment of the present invention, a method for preparing the above-mentioned blue-green light-emitting quantum dots is provided. The preparation method includes The following steps: prepare Cd precursor stock solution, S precursor stock solution, Se precursor stock solution, Zn-Cd precursor stock solution as raw material for standby; prepare CdS n Se 1-n Quantum dots; as CdS n Se 1-n Quantum dots as the core, in CdS n Se 1-nCdS buffer layer, Zn 0.5 Cd 0.5 The X buffer layer, and the ZnS shell, obtain blue-green luminescent quantum dots, wherein, 0

[0026] The preparation method of the blue-green light-emitting quantum dots provided by the present invention is prepared by using a phosphine-free method, which reduces the cost of raw materials and reduces the toxicity. At the ...

Embodiment 1

[0094] Preparation of CdS 0.5 Se 0.5 / CdS / Zn 0.5 CD 0.5 S / ZnS quantum dots, its preparation method comprises the following steps:

[0095] (1) Preparation of precursor

[0096] 1) Preparation of Cd precursor stock solution: 9mmolCdO, 27mmolOA, and 21ml of liquid paraffin were placed in a 50ml three-neck flask, heated to 100°C and exhausted for 30min under nitrogen protection, then heated to 260°C for 60min, then cooled to 130°C °C to obtain a Cd precursor stock solution for use.

[0097] 2) Preparation of Zn precursor stock solution: 3mmol ZnO, 25mmol OA, 22ml liquid paraffin were placed in a 50ml three-neck bottle, under the protection of nitrogen, heated to 100°C to exhaust for 30min, then heated to 300°C for 80min, cooled to 100°C °C to obtain the Zn precursor stock solution for future use.

[0098] 3) Preparation of Zn-Cd precursor stock solution: place 4.5mmol of ZnO, 4.5mmol of CdO, 27mmol of OA, and 21ml of liquid paraffin in a 50ml three-necked bottle, and heat t...

Embodiment 2-5

[0113] Quantum dots in Examples 2-5 are shown in Table 2.

[0114] The preparation method of Examples 2-5 refers to the method provided in Example 1.

[0115] Table 2.

[0116]

quantum dot

Example 1

CdS 0.5 Se 0.5 / CdS / Zn 0.5 CD 0.5 S / ZnS

Example 2

CdS 0.875 Se 0.125 / CdS / Zn 0.5 Cd 0.5 S / ZnS

Example 3

CdS 0.75 Se 0.25 / CdS / Zn 0.5 CD 0.5 S / ZnS

Example 4

CdS 0.25 Se 0.75 / CdS / Zn 0.5 Cd 0.5 S / ZnS

Example 5

CdS 0.125 Se 0.875 / CdS / Zn 0.5 Cd 0.5 S / ZnS

Comparative example 1

CdSe

[0117] (3), the CdS prepared by Examples 1 to 5 n Se 1-n Detection of nuclear quantum dots (fluorescence, absorption spectrum test):

[0118] Test instrument: PC2000-ISA spectrometer of OceanOptics is the fluorescence and absorption spectrometer, and the excitation light source is a 365nm portable ultraviolet lamp.

[0119] Test result: if figure 1 shown.

[0120] figure 1...

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Abstract

The invention discloses blue-green luminescent quantum dots and a preparation method therefor. Each quantum dot comprises a CdS(n)Se(1-n) core, a CdS buffer layer, a Zn(0.5)Cd(0.5)X buffer layer and a ZnS shell. In the CdS(n)Se(1-n) core, n is greater than 0 and is smaller than 1. The CdS buffer layer coats the outer periphery of the CdS(n)Se(1-n) core, the Zn(0.5)Cd(0.5)X buffer layer coats the outer periphery of the CdS buffer layer, and X is S or Se; and the ZnS shell coats the outer periphery of the Zn(0.5)Cd(0.5)X buffer layer. According to the blue-green luminescent quantum dots, through introducing the CdS buffer layer and the Zn(0.5)Cd(0.5)X buffer layer sequentially, the lattice mismatch degree of a core-shell structure is lowered, and the blue-green luminescent quantum dots in the wavelength range of 450nm to 550nm are formed, so that the maximum brightness of an QD-LED using the blue-green luminescent quantum dots can reach 4,700cd/m<2> or more.

Description

technical field [0001] The invention relates to the field of semiconductor materials, in particular to a blue-green luminescent quantum dot and a preparation method thereof. Background technique [0002] Quantum dots, also known as nanocrystals, are nanoparticles composed of II-VI or III-V elements. In quantum dots, electrons and holes are quantum-confined, and the continuous energy band structure becomes a discrete energy level structure with molecular characteristics, which can emit fluorescence after being excited. Based on quantum effects, quantum dots have broad application prospects in solar cells, light-emitting devices, optical biomarkers and other fields. [0003] With the rapid development of QD-LED device research, the performance parameters of red and green LEDs can meet the application needs, but the performance indicators of blue LEDs are still very low. At present, the status and problems of blue-green light-emitting quantum dots suitable for blue LEDs are a...

Claims

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Application Information

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IPC IPC(8): C09K11/88C09K11/02B82Y40/00B82Y20/00
Inventor 周维赵严帅
Owner BYD CO LTD
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