Large-scale preparation method of superhard material quantum dots
By sonicating the method of preparing quantum dots in solution of superhard material powder, the problem of difficulty in preparing high-chemical bond energy sub-dots in large quantum in the prior art is solved, and efficient preparation of small-particle-sized quantum dots is achieved, and it is used in photodetectors, solar cells and quantum communication technologies.
Patent Information
- Application Number
- CN202311783856.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-22
- Publication Date
- 2025-07-01
AI Technical Summary
It is difficult to efficiently prepare high-chemical bond energy superhard material quantum dots in large quantum, especially those of diamond, silicon carbide, boron nitride and other materials. The preparation method is complex and it is difficult to obtain quantum dots with small particle sizes.
By sonicating the ultra-hard material powder in solution, high-pressure collision occurs between the powder particles, breaking chemical bonds to form quantum dots, and then leaving the upper layer solution to obtain quantum dots.
Large-scale preparation of superhard material quantum dots has been achieved, with a particle size of up to 1 nm and has good luminescence characteristics. It is suitable for photodetectors, solar cells and quantum communication technologies.
Smart Images
Figure CN120229725A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a method for large-scale preparation of superhard material quantum dots, belonging to the technical field of semiconductor material preparation. Background Art
[0002] Superhard materials such as silicon carbide, cubic boron nitride, and diamond are all important semiconductors. In particular, diamond is called the ultimate semiconductor and has important applications in power electronics, energy information, integrated circuits, etc. In recent years, zero-dimensional quantum dot materials have been widely developed, but there is a lack of a simple and large-scale preparation method for quantum dots with high chemical bond energy. Most quantum dots are obtained through relatively complex chemical reaction methods under temperature control, and it is difficult to obtain quantum dots with strong chemical bond energy and high hardness such as diamond, silicon carbide, and boron nitride by these methods. If a large-scale preparation method for this type of quantum dot can be provided, it will provide a new path for the application development of quantum dots. From another perspective, we rarely think about turning large particles into small quantum dots. But in fact, if two fine powder balls collide with each other, one of the balls can be broken, and multiple mutual collisions can achieve a rapid reduction in the diameter of the small balls, which theoretically decreases sharply in a power-of-2 manner; based on this idea, the present invention proposes a method for large-scale preparation of superhard material quantum dots. Summary of the Invention
[0003] The purpose of the present invention is to provide a method for large-scale preparation of superhard material quantum dots in view of the deficiencies of the prior art.
[0004] The technical solution adopted by the present invention is as follows:
[0005] A method for large-scale preparation of superhard material quantum dots includes the following steps:
[0006] Put the superhard material powder into a solution;
[0007] Perform ultrasonic treatment;
[0008] Let the obtained solution stand still to obtain the upper-layer solution; that is, obtain the superhard material quantum dot solution.
[0009] In the above technical solution, further, the superhard material is one or more of silicon carbide, diamond, cubic boron nitride, and boron carbide.
[0010] Further, the solution is one or more of oleic acid, toluene, NMP, IPA, DMF, acetone, alcohol, and water.
[0011] Further, the frequency of the ultrasonic wave is not less than 10 KHz, the power is not less than 100 W, and the ultrasonic time is from 10 seconds to 10,000 hours.
[0012] The beneficial effects of the present invention compared with the prior art are as follows:
[0013] The preparation process of the present invention is simple, and the obtained quantum dots can reach 1 nm. Moreover, they can be used to prepare superhard quantum dots such as diamond and silicon carbide. These quantum dots have good luminescence properties. The birth of superhard quantum dots will provide new development paths for the fields of photodetectors, solar cells, integrated circuits, and quantum communication technologies. Brief Description of the Drawings
[0014] Figure 1 is the appearance of the quantum dot solution obtained in Example 1;
[0015] Figure 2a 、 2b 、2c are TEM images of silicon carbide quantum dots in Example 1;
[0016] Figure 3 is the Raman spectrum of silicon carbide quantum dots in Example 1.
[0017] Figure 4 is the luminescence performance spectrum of beta silicon carbide quantum dots in Example 2.
[0018] Figure 5a 、 5b is the TEM image of beta silicon carbide quantum dots in Example 2.
[0019] Figure 6 is the XPS spectrum of alpha silicon carbide quantum dots in Example 3.
[0020] Figure 7a 、 7b is the TEM image of alpha silicon carbide quantum dots in Example 3.
[0021] Figure 8 is the appearance of the diamond quantum dot solution obtained in Example 4.
[0022] Figure 9 is the TEM image of diamond quantum dots in Example 4.
[0023] Figure 10 is the Raman spectrum of diamond quantum dots in Example 4.
[0024] Figure 11 is the XPS spectrum of diamond quantum dots in Example 5.
[0025] Figure 12 is the TEM image of cubic boron nitride quantum dots in Example 6.
[0026] Figure 13 is the XPS spectrum of boron carbide quantum dots in Example 7.
[0027] Figure 14 It is the TEM image of the boron carbide quantum dots of Example 7.
[0028] Figure 15 It is the Raman spectrum of the boron carbide quantum dots of Example 7.
[0029] Figure 16 It is the optical photograph of the cubic boron nitride and diamond hybrid quantum dots of Example 8. Detailed implementation manners
[0030] The technical solution of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.
[0031] The present invention can realize the batch preparation of superhard material quantum dots by using a simple method of ultrasonic treatment in solution. The method is simple and suitable for large-scale production.
[0032] The preparation method of the quantum dots of the present invention includes the following steps:
[0033] 1) Obtain superhard material powders such as silicon carbide, diamond, cubic boron nitride, boron carbide, etc.; take one or more of them. In particular, some diamond powders can be further mixed in the selected superhard material powders, which is more conducive to improving the yield of quantum dots;
[0034] 2) Put the selected superhard material powders into solutions such as oleic acid, toluene, NMP, IPA, DMF, acetone, alcohol, water, etc., or a mixed solution of any multiple of them to form a mixed solution, and perform ultrasonic treatment; under the action of ultrasonic waves, violent collisions occur between the superhard material powder particles, thereby generating a huge pressure (up to dozens of GPa) impact between the extremely small contact surfaces of the powder particles, so that some chemical bonds of the powder particles are broken, and quantum dots are formed during the continuous collision and splitting process.
[0035] 3) Let the reactants stand for precipitation;
[0036] 4) Take the upper solution, and a liquid containing a large number of quantum dots is obtained.
[0037] In the method of the present invention, the dosage of the superhard material powder and the solution is usually not less than 0.01 mg / mL.
[0038] The ultrasonic wave used usually has a frequency of not less than 10 KHz and a power of not less than 100 W. The ultrasonic treatment time can be long or short, and can be from 10 seconds to 10,000 hours. When the ultrasonic frequency and power are high enough, the ultrasonic time can be shorter, and it can even be completed in a few seconds; this method does not require controlling the reaction temperature and can be prepared at room temperature or high temperature.
[0039] The superhard material powders and solutions used in the present invention can be directly purchased.
[0040] Example 1:
[0041] 1) Add 0.2 g of crystalline silicon carbide powder to 50 mL of NMP solution;
[0042] 2) Place it in an ultrasonic machine and ultrasonicate for half an hour at a power of 5 kW and a frequency of 20 KHz;
[0043] 3) Let it precipitate for 10 minutes, and pour the upper non-precipitate into a clean bottle;
[0044] Figure 1 is the appearance of the quantum dot solution obtained in this example, Figure 2a 、 2b 、2c is the TEM image of the quantum dots obtained in this example. It can be seen that a large number of quantum dots are prepared, and their particle sizes are in the range of 1 - 5 nm; Figure 3 is the Raman spectrum of the quantum dots obtained in this example. It can be clearly seen from the Raman spectrum that the peaks at 777 cm -1 and 957 cm -1 correspond to the Raman peak positions of silicon carbide in the TO and LO directions respectively.
[0045] Example 2:
[0046] 1) Add 200 g of beta crystalline silicon carbide powder to 50 mL of NMP solution;
[0047] 2) Place it in an ultrasonic machine and ultrasonicate for half an hour at a power of 2 kW and a frequency of 20 KHz;
[0048] 3) Let it precipitate for 60 minutes, and pour the upper non-precipitate into a clean bottle;
[0049] Figure 4 is the luminescence performance spectrum of the quantum dots obtained in this example. It can be seen that the luminescence peak position is significantly blue-shifted compared to the luminescence near 500 nm of the bulk, Figure 5a 、 5b is the TEM image of the quantum dots obtained in this example.
[0050] Example 3:
[0051] 1) Add 300 g of alpha crystalline silicon carbide powder to 50 mL of acetone solution;
[0052] 2) Place it in an ultrasonic machine and ultrasonicate for half an hour at a power of 1 kW and a frequency of 20 KHz;
[0053] 3) Let it precipitate for 30 minutes, and pour the upper non-precipitate into a clean bottle;
[0054] Figure 6The XPS spectrum of the quantum dots obtained in this example is shown. The carbon peaks are located at 284.3 eV and 281.7 eV, and the silicon peak is at 99.8 eV, indicating that the obtained quantum dots are silicon carbide quantum dots. Figure 7a 、 7b The TEM image of the quantum dots obtained in this example is shown.
[0055] Example 4:
[0056] 1) Add 100 g of diamond powder to 500 mL of IPA solution;
[0057] 2) Place it in an ultrasonic machine and ultrasonicate for half an hour at a power of 200 watts and a frequency of 50 KHz;
[0058] 3) Let it precipitate for 10 minutes, and pour the upper non-precipitate into a clean bottle;
[0059] Figure 8 The photo of the quantum dot solution obtained in this example is shown. Figure 9 The TEM image of the obtained diamond quantum dots is shown. Figure 10 The Raman spectrum of the quantum dots obtained in this example is shown. It can be seen that due to the lattice relaxation caused by collisions, the original two peaks of diamond degenerate to form a single peak with a relatively large full width at half maximum.
[0060] Example 5:
[0061] 1) Add 50 g of diamond powder to 20 mL of NMP solution;
[0062] 2) Place it in an ultrasonic machine and ultrasonicate for half an hour at a power of 3 kW and a frequency of 10 KHz;
[0063] 3) Let it precipitate for 20 minutes, and pour the upper non-precipitate into a clean bottle;
[0064] Figure 11 The XPS spectrum of the quantum dots obtained in this example is shown. The peak near 284.5 eV indicates that the sample is diamond.
[0065] Example 6:
[0066] 1) Add 10 g of cubic boron nitride powder to 100 mL of NMP solution;
[0067] 2) Place it in an ultrasonic machine and ultrasonicate for half an hour at a power of 200 watts and a frequency of 20 KHz;
[0068] 3) Let it precipitate for 10 minutes, and pour the upper non-precipitate into a clean bottle;
[0069] Figure 12 The TEM image of the quantum dots obtained in this example is shown. A large number of quantum dots can be found.
[0070] Example 7:
[0071] 1) Add 30 g of boron carbide powder to 1000 mL of aqueous solution;
[0072] 2) Place it in an ultrasonic machine and ultrasonicate for half an hour at a power of 1 kilowatt and a frequency of 20 KHz;
[0073] 3) Precipitate for 5 minutes and pour the upper non-precipitate into a clean bottle;
[0074] Figure 13 It is the XPS diagram of the quantum dots obtained in this example. The peak of boron element is located at 187 eV, and the carbon peak is located at 284.6 eV, proving that the obtained material is boron carbide. Figure 14 It is the TEM diagram of the quantum dots obtained in this example. Figure 15 It is the Raman spectrum of the quantum dots obtained in this example. The peaks near the wavenumbers of 476 and 528 are the characteristic peaks of boron carbide material.
[0075] Example 8:
[0076] 1) Add 30 g of cubic boron nitride and 5 mg of diamond mixed powder to 100 mL of DMF solution;
[0077] 2) Place it in an ultrasonic machine and ultrasonicate for half an hour at a power of 1 kilowatt and a frequency of 20 KHz;
[0078] 3) Precipitate for 30 minutes and pour the upper non-precipitate into a clean bottle;
[0079] Figure 16 It is the optical picture of the quantum dot solution obtained in this example. There is still a large amount of quantum dot solution after precipitation.
[0080] The above-described examples are only partial implementation schemes of the present invention, but they are not intended to limit the present invention. Those of ordinary skill in the relevant technical field can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all technical solutions obtained by means of equivalent replacement or equivalent transformation fall within the protection scope of the present invention.
Claims
1. A method for large-scale preparation of superhard material quantum dots, characterized in that, It includes the following: Put the superhard material powder into the solution; Perform ultrasonic treatment; Let the obtained solution stand still to obtain the upper-layer solution; namely, obtain the superhard material quantum dot solution.
2. The large-scale preparation method of the superhard material quantum dots according to claim 1, characterized in that The superhard material is one or more of silicon carbide, diamond, cubic boron nitride, and boron carbide.
3. The large-scale preparation method of the superhard material quantum dots according to claim 1, characterized in that, The solution is one or more of oleic acid, toluene, NMP, IPA, DMF, acetone, alcohol, and water.
4. The large-scale preparation method of the superhard material quantum dots according to claim 1, characterized in that, The frequency of the ultrasonic wave is not less than 10KHz, and the power is not less than 100W.