CN112159652A - Preparation method of CdSe/CdS core-shell structure quantum dot - Google Patents
Preparation method of CdSe/CdS core-shell structure quantum dot Download PDFInfo
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- 239000002096 quantum dot Substances 0.000 title claims abstract description 76
- UHYPYGJEEGLRJD-UHFFFAOYSA-N cadmium(2+);selenium(2-) Chemical compound [Se-2].[Cd+2] UHYPYGJEEGLRJD-UHFFFAOYSA-N 0.000 title claims abstract description 67
- 239000011258 core-shell material Substances 0.000 title claims abstract description 28
- 238000002360 preparation method Methods 0.000 title claims abstract description 11
- BUGBHKTXTAQXES-UHFFFAOYSA-N Selenium Chemical compound [Se] BUGBHKTXTAQXES-UHFFFAOYSA-N 0.000 claims abstract description 45
- 239000000243 solution Substances 0.000 claims abstract description 42
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- 229910052711 selenium Inorganic materials 0.000 claims abstract description 29
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- 239000011550 stock solution Substances 0.000 claims abstract description 29
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- AUIZLSZEDUYGDE-UHFFFAOYSA-L cadmium(2+);diacetate;dihydrate Chemical compound O.O.[Cd+2].CC([O-])=O.CC([O-])=O AUIZLSZEDUYGDE-UHFFFAOYSA-L 0.000 claims abstract description 9
- 229940057995 liquid paraffin Drugs 0.000 claims abstract description 9
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 9
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 claims abstract description 6
- 239000000843 powder Substances 0.000 claims abstract description 6
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 claims description 19
- 238000003756 stirring Methods 0.000 claims description 16
- 238000000034 method Methods 0.000 claims description 13
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 10
- 229910052804 chromium Inorganic materials 0.000 claims description 10
- 239000011651 chromium Substances 0.000 claims description 10
- 238000000926 separation method Methods 0.000 claims description 10
- 229940048181 sodium sulfide nonahydrate Drugs 0.000 claims description 7
- WMDLZMCDBSJMTM-UHFFFAOYSA-M sodium;sulfanide;nonahydrate Chemical compound O.O.O.O.O.O.O.O.O.[Na+].[SH-] WMDLZMCDBSJMTM-UHFFFAOYSA-M 0.000 claims description 7
- CXKCTMHTOKXKQT-UHFFFAOYSA-N cadmium oxide Inorganic materials [Cd]=O CXKCTMHTOKXKQT-UHFFFAOYSA-N 0.000 claims description 6
- CFEAAQFZALKQPA-UHFFFAOYSA-N cadmium(2+);oxygen(2-) Chemical compound [O-2].[Cd+2] CFEAAQFZALKQPA-UHFFFAOYSA-N 0.000 claims description 6
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- 229910000423 chromium oxide Inorganic materials 0.000 claims description 5
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- 229910052979 sodium sulfide Inorganic materials 0.000 abstract 1
- GRVFOGOEDUUMBP-UHFFFAOYSA-N sodium sulfide (anhydrous) Chemical compound [Na+].[Na+].[S-2] GRVFOGOEDUUMBP-UHFFFAOYSA-N 0.000 abstract 1
- 239000011257 shell material Substances 0.000 description 16
- RMZAYIKUYWXQPB-UHFFFAOYSA-N trioctylphosphane Chemical compound CCCCCCCCP(CCCCCCCC)CCCCCCCC RMZAYIKUYWXQPB-UHFFFAOYSA-N 0.000 description 6
- ZMBHCYHQLYEYDV-UHFFFAOYSA-N trioctylphosphine oxide Chemical compound CCCCCCCCP(=O)(CCCCCCCC)CCCCCCCC ZMBHCYHQLYEYDV-UHFFFAOYSA-N 0.000 description 6
- 239000000463 material Substances 0.000 description 5
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- 239000012299 nitrogen atmosphere Substances 0.000 description 4
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- 229910052698 phosphorus Inorganic materials 0.000 description 4
- 239000011574 phosphorus Substances 0.000 description 4
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 3
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- 239000001301 oxygen Substances 0.000 description 1
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- 238000000859 sublimation Methods 0.000 description 1
- 230000008022 sublimation Effects 0.000 description 1
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Abstract
A preparation method of CdSe/CdS core-shell structure quantum dots belongs to the technical field of semiconductors and luminescent nano materials. The invention firstly adds chromic oxide, paraffin and oleic acid into a flask, selenium powder and paraffin are added into another flask for nitrogen protection and heating to obtain a precursor solution, then oleylamine is added into a selenium precursor, then cadmium precursor is added, cadmium acetate dihydrate is dissolved into liquid paraffin as a shell cadmium precursor solution of a CdS shell, sodium sulfide powder nonahydrate is added into a 4CdSe quantum dot stock solution and is dripped into the (shell cadmium precursor solution, and uniform CdSe/CdS nuclear shell structure quantum dot stock solution is generated by reaction.
Description
Technical Field
The invention relates to the technical field of semiconductors and luminescent nano materials, in particular to a background technology for preparing CdSe/CdS nuclear shell structure quantum dots
Background
The quantum dot optical semiconductor technology is a novel optical semiconductor at nanometer quantum level, generally, the optical semiconductor is a sphere or a sphere with similar shape, and the diameter of the quantum dot is usually between 2 and 20 nm. When the semiconductor quantum dot is excited by energy to emit light, after certain energy is obtained, excited-state electrons in the quantum dot and the empty band jump to a conduction band, and an excited-state hole corresponding to the quantum dot is left between the quantum dot and the empty band. When the electrons in the excited state are unstable again in the conduction band, the electrons are transited back to the empty band again to be recombined with one hole state electron on the empty band, and another form of energy obtaining and releasing is quantum dot luminescence. This approach is the dominant electroluminescent material approach for semiconductor quantum luminescent dots. Among the luminescent quantum dots, the II-VI group semiconductor quantum dots, such as CdSe, CdS, ZnS and the like, are the most studied and play an important role in numerous research fields such as biomedicine, genetics and the like. The cladding made of the wide band gap material can reduce and eliminate the phenomenon of fluorescence efficiency reduction caused by the surface state of the core quantum dots and unsaturated dangling bonds.
Currently, the preparation methods of CdSe/CdS are divided into aqueous phase synthesis methods and organic synthesis methods. Although the quantum dots prepared by the aqueous phase synthesis method have the characteristics of low cost and good water solubility, the quantum dots have low fluorescence intensity and imperfect crystallization, and the quantum dots synthesized by the organic synthesis method have the characteristics of uniform size distribution, good fluorescence performance, high yield and the like. In the process of nucleation, it is very important to select a suitable shell material, both to realize epitaxial growth on the surface of the core quantum dot and to ensure that the core quantum dot does not independently nucleate at a specific temperature. In the traditional method, trioctylphosphine oxide (TOPO) and tri-n-octylphosphine (TOP) are often used as surfactants (such as patent CN104910918A, a core-shell quantum dot material and a preparation method thereof), sublimed sulfur is used for providing a sulfur precursor, and CdSe/CdS synthesis is carried out at high temperature (300 ℃) in the absence of oxygen and water. Organic phosphorus is expensive and toxic, has great environmental pollution, requires too high temperature for sulfur sublimation, is difficult to control experiments, and is not beneficial to the growth of quantum dots.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides another method for preparing the quantum dots with the CdSe/CdS core-shell structure. The preparation method adopts solvents such as paraffin, oleic acid and the like to replace organic phosphorus reagents such as trioctylphosphine oxide (TOPO), tri-n-octylphosphine (TOP) and the like which are commonly used in the past, and aims to cover a CdS core layer with proper thickness on the surface of the CdSe core layer to prepare the CdSe/CdS core-shell structure quantum dot.
The experimental reagent of the method for preparing the CdSe/CdS nuclear shell structure quantum dot comprises the following steps: cadmium oxide, selenium powder, oleic acid, liquid paraffin, n-hexane, methanol, chloroform, sodium sulfide nonahydrate, oleylamine, cadmium acetate dihydrate and the like.
In order to achieve the purpose, the technical scheme of the invention comprises the following steps:
(1) sequentially adding 1.285g of chromium oxide, 5-10ml of paraffin and 10-25ml of oleic acid into a three-neck flask, wherein the three-neck flask is called a chromium bottle; 0.789g of selenium powder and 30-50ml of paraffin were added to another three-necked flask, which was called a selenium bottle. Connecting a condensation pipe; inserting a temperature detector; connecting a nitrogen pipe to remove air from the two flasks; stir at room temperature for 20-40 minutes to fully evacuate the air from the flask.
(2) The two flasks were heated with continuous nitrogen gas introduction and stirring; heating the chromium bottle to 140-160 ℃ and maintaining for 30-50 minutes until the solution is light yellow, indicating that the cadmium oxide is completely dissolved and is used as a cadmium precursor solution for later use; the selenium bottle is heated to 230 ℃ and maintained for 40-60 minutes, and the selenium powder is bright orange after being completely dissolved and is used as a selenium precursor solution.
(3) Continuously introducing nitrogen, stirring and heating to maintain the temperature of 210-230 ℃, adding oleylamine into the selenium precursor solution according to the proportion of adding 2-10ml of oleylamine into each 1mmol of selenium powder, adding the cadmium precursor into the selenium precursor solution according to the molar ratio of cadmium to selenium of 1:1-10 after 1-10 minutes to form core CdSe quantum dot stock solution, and cooling to 40-50 ℃ for later use.
(4) Taking a small amount of CdSe quantum dot stock solution, centrifugally separating and storing the CdSe quantum dot stock solution in n-hexane for analyzing and comparing the nuclear CdSe quantum dots.
(5) 0.2668g of cadmium acetate dihydrate is dissolved in 10-30ml of liquid paraffin to be used as a shell cadmium precursor solution of the CdS shell;
(6) adding 0.48g of sodium sulfide nonahydrate powder into CdSe quantum dot stock solution at the temperature of 40-50 ℃, stirring and heating to 150 ℃ at the temperature of 130-; and (3) uniformly dripping the shell cadmium precursor solution obtained in the step (6) within 1-5 minutes, and reacting to generate uniform CdSe/CdS core-shell structure quantum dot stock solution.
(7) And (4) purifying the CdSe/CdS core-shell structure quantum dot stock solution obtained in the step (6) by adopting a centrifugal separation method. After separation and purification, the extract is dissolved in n-hexane for characterization and preservation.
Has the advantages that: according to the preparation method of the CdSe/CdS core-shell structure quantum dot, solvents such as paraffin and oleic acid are adopted to replace organic phosphorus reagents such as trioctylphosphine oxide (TOPO) and tri-n-octylphosphine (TOP) which are commonly used in the past, so that the reaction temperature is lower, and the method is more environment-friendly; after the CdSe shell is coated by the core CdSe quantum dot, the oxidation of the core CdSe can be prevented, so that the surface defects of the quantum dot are repaired, the phenomenon that the quantum yield absorption peak and the fluorescence emission peak of the quantum dot have obvious red shift is improved, the half-peak width of the emission peak is obviously reduced, the size of the quantum dot can be increased after the quantum dot is coated, the size distribution is uniform, the performance is good, and the quantum dot has a good prospect in photoluminescence and electroluminescence materials or applied to the biological field. The preparation method of the CdSe/CdS core-shell structure quantum dot has the advantages of simple and feasible process and good repeatability.
Drawings
FIG. 1(a)/(b)/(c) is an absorption/fluorescence spectrum, a transmission electron microscope spectrum and a distribution spectrum of particle size sites of 3.6nmcdSe quantum dots, respectively.
FIG. 2 is a fluorescence photograph of CdSe quantum dots with different sizes obtained by the present invention, wherein the particle diameters of the labels 1-10 are from 3.0nm to 4.5nm, the particle diameter of the label 1 is 3.0nm, and the particle diameter of the label 10 is 4.5 nm.
FIG. 3 is the absorption spectrum and fluorescence picture of 3.6nm core CdSe quantum dots and CdSe/CdS core-shell structure quantum dots formed on the basis of the core CdSe quantum dots.
Detailed Description
In order that the objects, technical solutions and advantages of the present invention will become more apparent, the present invention will be further described in detail with reference to the accompanying drawings in conjunction with the following specific embodiments.
Example 1
(1) 1.285g of chromium oxide, 6ml of paraffin and 25ml of oleic acid are added in sequence to a three-necked flask, referred to as a chromium bottle; 0.789g of selenium powder and 30ml of paraffin were added to another three-necked flask, which was referred to as a selenium bottle. Connecting a condensation pipe; inserting a temperature detector; connecting a nitrogen pipe to remove air from the two flasks; stir at room temperature for 25 minutes to fully evacuate the air from the flask.
(2) The two flasks were heated with continuous nitrogen gas introduction and stirring; heating the chromium bottle to 150 ℃ and maintaining the temperature for more than 30 minutes, and when the solution is light yellow, indicating that the cadmium oxide is completely dissolved and is used as a cadmium precursor solution for later use; and heating the selenium bottle to 220 ℃ and maintaining for 50 minutes, wherein the selenium powder is bright orange after being completely dissolved and is used as a selenium precursor solution.
(3) Continuously introducing nitrogen, stirring and heating to maintain the temperature at 230 ℃, adding oleylamine into the selenium precursor solution, adding a cadmium precursor into the selenium precursor solution after 5 minutes according to the molar ratio of cadmium to selenium of 1:1-10 to form a core CdSe quantum dot stock solution, and cooling to 40-50 ℃ for later use.
(4) Taking a small amount of CdSe quantum dot stock solution, centrifugally separating and storing the CdSe quantum dot stock solution in n-hexane for analyzing and comparing the nuclear CdSe quantum dots.
(5) 0.2668g of cadmium acetate dihydrate is dissolved in 20ml of liquid paraffin to be used as a shell cadmium precursor solution of the CdS shell;
(6) adding 0.48g of sodium sulfide nonahydrate powder into CdSe quantum dot stock solution at 40 ℃, stirring and heating to 130 ℃; and (3) uniformly dripping the shell cadmium precursor solution obtained in the step (5) within 1-5 minutes, and reacting to generate uniform CdSe/CdS core-shell structure quantum dot stock solution.
(7) And (4) purifying the CdSe/CdS core-shell structure quantum dot stock solution obtained in the step (6) by adopting a centrifugal separation method. After separation and purification, the extract is dissolved in n-hexane for characterization and preservation.
Example 2
(1) 1.285g of chromium oxide, 10ml of paraffin and 15ml of oleic acid are added into a three-neck flask (chromium bottle); 0.789g of selenium powder and 50ml of paraffin were put into another three-necked flask (selenium bottle). Connecting a condensation pipe; inserting a temperature detector; connecting a nitrogen pipe to remove air from the two solutions; stirred for 30 minutes.
(2) The two flasks were heated with continuous nitrogen gas introduction and stirring; heating the chromium bottle to 150 ℃, and taking the solution as a cadmium precursor solution for later use when the cadmium oxide is completely dissolved and the solution is light yellow; and heating the selenium bottle to 220 ℃ and maintaining for 40 minutes, wherein the selenium powder is bright orange after being completely dissolved and is used as a selenium precursor solution.
(3) Continuously introducing nitrogen, stirring, heating and maintaining at 220 ℃, adding oleylamine into the selenium precursor solution according to the proportion of adding 2-10ml of oleylamine into each 1mmol of selenium powder, and adding the cadmium precursor into the selenium precursor solution according to the molar ratio of cadmium to selenium of 1:1-10 after 1-10 minutes to form the core CdSe quantum dot stock solution.
(4) Taking a small amount of CdSe quantum dot stock solution, centrifugally separating and storing the CdSe quantum dot stock solution in n-hexane for analyzing and comparing the nuclear CdSe quantum dots.
(5) Dissolving cadmium acetate dihydrate into liquid paraffin by the method (1) to be used as a shell cadmium precursor solution of the CdS shell;
(6) uniformly adding sodium sulfide nonahydrate powder into the prepared CdSe quantum dot stock solution, and heating to 140 ℃ while rapidly stirring; and (5) uniformly dripping the shell cadmium precursor solution obtained in the step (5) to react to generate uniform CdSe/CdS core-shell structure quantum dot stock solution.
(7) And (4) purifying the CdSe/CdS core-shell structure quantum dot stock solution obtained in the step (6) by adopting a centrifugal separation method. After separation and purification, the extract is dissolved in n-hexane for characterization and preservation.
Example 3
1. Synthesizing CdSe quantum dots with specific sizes as cores;
(a) in two flasks, selenium powder is dissolved in liquid paraffin, and cadmium oxide is dissolved in a paraffin/oleic acid mixed system; respectively heating to 220 ℃ and 150 ℃ in a nitrogen atmosphere, and respectively obtaining a selenium precursor solution and a cadmium precursor solution after full dissolution;
(b) adding a certain amount of oleylamine into the selenium precursor solution in the nitrogen atmosphere; maintained at 220 ℃;
(c) in a nitrogen atmosphere, maintaining the temperature, adding a certain amount of cadmium precursor solution into the selenium precursor solution added with oleylamine, and reacting for a period of time to obtain CdSe quantum dot stock solution; the CdSe quantum dot size can be adjusted by changing the material ratio, the reaction time and the temperature;
(d) a small amount of CdSe quantum dot stock solution can be taken and subjected to centrifugal separation to obtain normal hexane, and CdSe quantum dots with specific sizes are obtained for characterization and analysis;
2. coating a shell material CdS with a specific thickness;
dissolving cadmium acetate dihydrate in liquid paraffin to serve as a shell cadmium precursor solution; uniformly adding sodium sulfide nonahydrate powder into the synthesized CdSe quantum dot stock solution, stirring and heating in a nitrogen atmosphere, maintaining the temperature at 140 ℃, adding a certain amount of shell cadmium precursor solution, and reacting for a period of time to generate CdSe/CdS core-shell structure quantum dots; and purifying the synthesized CdSe/CdS core-shell structure quantum dots by a centrifugal separation method.
In conclusion, the preparation method of the quantum dot with the CdSe/CdS core-shell structure effectively solves the safety problem of the quantum dot caused by using an organic phosphorus reagent and reduces the reaction temperature. The CdSe/CdS quantum dots with the core-shell structure are prepared by covering proper CdS on the surface of CdSe, so that CdSe can be effectively prevented from being corroded and oxidized, the core-shell surface structure defect of the quantum dots is effectively repaired, and the quantum yield of the quantum dots is greatly improved.
While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (6)
1. A preparation method of CdSe/CdS core-shell structure quantum dots is characterized by comprising the following steps:
(1) sequentially adding chromium oxide, paraffin and oleic acid into a three-neck flask, wherein the three-neck flask is called a chromium bottle; adding selenium powder and paraffin into another three-neck flask, connecting a condenser tube, inserting a thermometer, connecting a nitrogen tube to remove air from the two flasks, and stirring at room temperature for 20-40 min to sufficiently remove air in the flasks;
(2) the two flasks were heated with continuous nitrogen gas introduction and stirring; heating the chromium bottle, and when the solution is light yellow, indicating that the cadmium oxide is completely dissolved, and using the solution as a cadmium precursor solution for later use; heating the selenium bottle, wherein the selenium powder is bright orange after being completely dissolved and is used as a selenium precursor solution;
(3) continuously introducing nitrogen, stirring and heating to maintain the temperature of 210-230 ℃, adding oleylamine into the selenium precursor solution according to the proportion of adding 2-10ml of oleylamine into each 1mmol of selenium powder, adding the cadmium precursor into the selenium precursor solution according to the molar ratio of cadmium to selenium of 1:1-10 after 1-10 minutes to form core CdSe quantum dot stock solution, and cooling to 40-50 ℃ for later use.
(4) Taking a small amount of CdSe quantum dot stock solution, centrifugally separating and storing the CdSe quantum dot stock solution in n-hexane for analyzing and comparing the nuclear CdSe quantum dots.
(5) Dissolving cadmium acetate dihydrate in liquid paraffin to serve as a shell cadmium precursor solution of the CdS shell;
(6) adding sodium sulfide nonahydrate powder into CdSe quantum dot stock solution, stirring and heating to 130-150 ℃; and (3) uniformly dripping the shell cadmium precursor solution obtained in the step (5) within 1-5 minutes, and reacting to generate uniform CdSe/CdS core-shell structure quantum dot stock solution.
(7) And (4) purifying the CdSe/CdS core-shell structure quantum dot stock solution obtained in the step (6) by adopting a centrifugal separation method. After separation and purification, the extract is dissolved in n-hexane for characterization and preservation.
2. The preparation method of the CdSe/CdS core-shell structure quantum dot as claimed in claim 1, wherein in step (1), 5-10ml of paraffin and 10-25ml of oleic acid are added to each 1.285g of chromium oxide in the chromium bottle; 30-50ml of paraffin is added into each 0.789g of selenium powder in the selenium bottle.
3. The method for preparing the quantum dot with the CdSe/CdS core-shell structure as claimed in claim 1, wherein the heating temperature of the chromium bottle in step (2) is 140-160 ℃, and the time is 30-50 min; the heating temperature of the selenium bottle is 210-230 ℃, and the time is 40-60 minutes.
4. The method for preparing CdSe/CdS core-shell quantum dots as claimed in claim 1, wherein the amount of oleylamine added in step (3) is 8ml per 1mmol of selenium powder.
5. The method for preparing CdSe/CdS core-shell quantum dots as claimed in claim 1, wherein in step (5), 10-30ml of liquid paraffin is added per 0.2668g of cadmium acetate dihydrate for dissolution.
6. The method for preparing CdSe/CdS core-shell quantum dots as claimed in claim 1, wherein in step (6), 0.48g of sodium sulfide nonahydrate is added per 0.2668g of cadmium acetate dihydrate.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112939822A (en) * | 2021-02-09 | 2021-06-11 | 浙江理工大学 | Quantum dot and method for preparing sulfonamide derivative by using same |
| CN115608382A (en) * | 2022-10-24 | 2023-01-17 | 上海科技大学 | Semiconductor nanocrystalline aggregate and preparation method and application thereof |
| CN115651638A (en) * | 2022-12-10 | 2023-01-31 | 福州大学 | PN junction CdSe/PbS/CdS quantum well material with one-dimensional core-shell heterostructure and preparation method thereof |
| CN115763615A (en) * | 2022-12-13 | 2023-03-07 | 常熟理工学院 | Self-driven photoelectric detector based on quantum dots and preparation method thereof |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110655923A (en) * | 2019-11-13 | 2020-01-07 | 大连民族大学 | Green preparation method of cadmium selenide quantum dots with specific size |
-
2020
- 2020-09-18 CN CN202010983001.8A patent/CN112159652A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110655923A (en) * | 2019-11-13 | 2020-01-07 | 大连民族大学 | Green preparation method of cadmium selenide quantum dots with specific size |
Non-Patent Citations (2)
| Title |
|---|
| XIEBING WANG等: "Stable efficient CdSe/CdS/ZnS core/multi-shell nanophosphors fabricated through a phosphine-free route for white light-emitting-diodes with high color rendering properties", 《JOURNAL OF MATERIALS CHEMISTRY》, vol. 21, 14 April 2011 (2011-04-14), pages 8558 - 8565 * |
| 朱莎: "在油酸-石蜡体系下CdS/CdSe量子点的制备及其光学性能研究", 《中国优秀硕士学位论文全文数据库 工程科技I辑》, no. 10, 15 October 2012 (2012-10-15), pages 014 - 95 * |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112939822A (en) * | 2021-02-09 | 2021-06-11 | 浙江理工大学 | Quantum dot and method for preparing sulfonamide derivative by using same |
| CN115608382A (en) * | 2022-10-24 | 2023-01-17 | 上海科技大学 | Semiconductor nanocrystalline aggregate and preparation method and application thereof |
| CN115651638A (en) * | 2022-12-10 | 2023-01-31 | 福州大学 | PN junction CdSe/PbS/CdS quantum well material with one-dimensional core-shell heterostructure and preparation method thereof |
| CN115763615A (en) * | 2022-12-13 | 2023-03-07 | 常熟理工学院 | Self-driven photoelectric detector based on quantum dots and preparation method thereof |
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