Preparation system of ZnO nanocrystalline

Abstract

A preparation system of ZnO nanocrystals belongs to the technical field of optical materials and comprises a preparation device of a ZnO seed crystal layer and a preparation device of a Co-doped ZnO nanorod array, the preparation device of the ZnO seed crystal layer is used for preparing the ZnO seed crystal layer firstly, then the prepared ZnO seed crystal layer is placed in the preparation device of the Co-doped ZnO nanorod array, and in the specific preparation process, the Co-doped ZnO nanorod array is prepared by using the preparation device of the ZnO seed crystal layer. A precursor solution is prepared under the mutual cooperation of a first chamber, a second chamber, a third chamber and a stirrer, then the precursor solution is introduced into a reaction kettle, the precursor solution and a ZnO seed crystal layer are subjected to a reaction in the high-pressure reaction kettle, a ZnO nanocrystal finished product is obtained, in the preparation mode, the preparation efficiency of the ZnO nanocrystal is improved, meanwhile, the yield of the ZnO nanocrystal is increased, and meanwhile the yield of the ZnO nanocrystal is increased. In a sealed environment, the purity of the ZnO crystal seed layer is ensured.

Description

Technical Field

[0001] The utility model belongs to the technical field of optical materials, and particularly relates to a preparation system of ZnO nanocrystals. Background Art

[0002] Zinc oxide (ZnO) is a new type of direct wide bandgap N-type semiconductor material with high exciton binding energy and good conductivity at room temperature. Due to its oxygen vacancy-specific electrical and optical properties, it has broad application prospects in light-emitting elements, optoelectronic devices, etc.

[0003] Doping is a simple and feasible method to improve the magnetic, optical and electrical properties of semiconductor materials. This is because the introduction of doping ions can change the specific surface area of ​​the material, produce lattice defects and change the bandgap width. By introducing appropriate amounts of magnetic elements (Fe, Mn, Ni, Co, etc.) into wide bandgap semiconductor materials, a diluted magnetic semiconductor material (DMS) can be formed. Co has a rich electronic state and its effect on the ZnO lattice is relatively weak. Therefore, Co is one of the ideal dopants for regulating optics. Among Co-doped II-VI ZnO-based diluted magnetic semiconductor materials, in DMS materials, Co-doped ZnO semiconductor materials have a rich electronic shell structure and have the ability to emit excitons at room temperature, so they have potential application value in the field of electronic spin device production.

[0004] However, in the actual preparation process, there are many interfering factors, such as air interference, doping of other substances in the seed layer, and the formation of an interference layer on the surface of the ZnO seed layer. This will cause the finished nanocrystal to fail to meet the requirements and have a low purity. Summary of the invention

[0005] In view of this, it is necessary to provide a preparation system of ZnO nanocrystals.

[0006] The utility model solves the technical problem by providing a system for preparing ZnO nanocrystals, comprising a device for preparing a ZnO seed layer and a device for preparing a Co-doped ZnO nanorod array, wherein the device for preparing the ZnO seed layer is used to prepare the ZnO seed layer, and the device for preparing the Co-doped ZnO nanorod array is used to prepare the ZnO seed layer into ZnO nanocrystals;

[0007] The ZnO seed layer preparation device comprises a reaction container, a vacuum pumping assembly, a sputtering assembly and a reaction base, wherein the vacuum pumping assembly is arranged on the reaction container and communicated with the interior of the reaction container, the sputtering assembly and the reaction base are arranged inside the reaction container, and the sputtering assembly is arranged above the reaction base;

[0008] The preparation device of the Co-doped ZnO nanorod array comprises a first chamber, a second chamber, a third chamber, a stirrer and a high-pressure reactor, wherein the first chamber, the second chamber and the third chamber are connected or closed to the stirrer, the stirrer is used to stir the solution, and the outlet of the stirrer is connected to the inlet of the high-pressure reactor for preparing ZnO nanocrystals.

[0009] Preferably, the vacuum pumping assembly includes a vacuum component and an inflator, both of which are arranged on the reaction container, the vacuum component is used to evacuate the air inside the reaction container, and the inflator is used to fill the reaction container with inert gas.

[0010] Preferably, the stirrer includes one of ultrasonic stirring or magnetic stirring.

[0011] Preferably, a bracket is provided in the high-pressure reactor, and the bracket comprises a polytetrafluoroethylene bracket.

[0012] Preferably, the ZnO nanocrystal preparation system further comprises a heating device, which is disposed between the ZnO seed layer preparation device and the Co-doped ZnO nanorod array preparation device and is used to heat the ZnO seed layer sample.

[0013] Beneficial effects: The ZnO nanocrystal preparation system comprises a ZnO seed layer preparation device and a Co-doped ZnO nanorod array preparation device. The ZnO seed layer is first prepared by using the ZnO seed layer preparation device, and then the prepared ZnO seed layer is placed in the Co-doped ZnO nanorod array preparation device. In a specific preparation process, a precursor solution is first prepared under the cooperation of a first chamber, a second chamber, a third chamber and a stirrer, and then the precursor solution is introduced into a reactor, so that the precursor solution and the ZnO seed layer react in a high-pressure reactor to obtain a ZnO nanocrystal finished product. In this preparation method, the preparation efficiency of the ZnO nanocrystal is improved, and at the same time, the purity of the ZnO seed layer is guaranteed in a sealed environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a device diagram of a ZnO nanocrystal preparation system of the utility model;

[0015] In the figure: a preparation device 10 for a ZnO seed layer, a reaction vessel 101, a vacuum assembly 102, a vacuum part 1021, an inflator 1022, a sputtering assembly 103, a reaction base 104, a preparation device 20 for a Co-doped ZnO nanorod array, a first chamber 201, a second chamber 202, a third chamber 203, a stirrer 204, a high-pressure reactor 205, and a heating device 30. DETAILED DESCRIPTION

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Please see Figure 1 , a system for preparing ZnO nanocrystals, comprising a ZnO seed layer preparation device 10 and a Co-doped ZnO nanorod array preparation device 20, wherein the ZnO seed layer preparation device 10 is used to prepare the ZnO seed layer, and the Co-doped ZnO nanorod array preparation device 20 is used to prepare the ZnO seed layer into ZnO nanocrystals;

[0018] The ZnO seed layer preparation device 10 comprises a reaction vessel 101, a vacuum assembly 102, a sputtering assembly 103 and a reaction base 104, wherein the vacuum assembly 102 is disposed on the reaction vessel 101 and communicated with the interior of the reaction vessel 101, the sputtering assembly 103 and the reaction base 104 are disposed inside the reaction vessel 101, and the sputtering assembly 103 is disposed above the reaction base 104;

[0019] The Co-doped ZnO nanorod array preparation device 20 includes a first chamber 201, a second chamber 202, a third chamber 203, a stirrer 204 and a high-pressure reactor 205. The first chamber 201, the second chamber 202 and the third chamber 203 are connected or closed to the stirrer 204. The stirrer 204 is used to stir the solution. The outlet of the stirrer 204 is connected to the inlet of the high-pressure reactor 205 for preparing ZnO nanocrystals.

[0020] When the ZnO seed layer preparation device 10 is used, a ZnO thin film is prepared on the reaction base 104. Before the sputtering assembly 103 is used for sputtering, the reaction container 101 is first evacuated by the vacuum assembly 102 to a vacuum of 1.33×10 -4Pa, then argon (Ar) is injected to ensure pressure balance. During sputtering, a 100% pure zinc oxide target is selected for pre-sputtering for 10 minutes to remove impurities on the surface. Secondly, the ZnO film is sputtered, and the temperature of the reaction base 104 is controlled at 30°C (the temperature control of the reaction base 104 can be selected according to the method in the conventional technology). The working pressure is controlled at 8.8Pa for sputtering for 30 minutes, and then a high-temperature heat treatment of 400°C is performed for 3 hours to obtain a ZnO seed layer film. After obtaining the ZnO seed layer film, a single crystal silicon wafer substrate sputtered with a ZnO seed layer is vertically placed in the Co-doped ZnO nanorod array preparation device 20, and a certain amount of Zn(CH3COO) 2 ·2H2O solution, analytically pure NaOH solution in the second chamber 202, and C4H6CoO4·4H2O dopant in the third chamber 203 are dissolved in deionized water and magnetically stirred until the solution becomes clear, and then the three mixed solutions are introduced into the stirrer 204, mixed and stirred for 2 hours to form a precursor solution, and the mixed solution is loaded into the high-pressure reactor 205, and reacted at 100°C for 3 hours. After the reaction is completed, until the sample is naturally cooled to room temperature, the single crystal silicon wafer is taken out with tweezers, washed with deionized water and filtered. Finally, the product is dispersed with anhydrous ethanol, and is dried at a constant temperature of 60°C, and the finished product is finally collected for characterization.

[0021] In a specific application scenario, a 100% pure ZnO zinc oxide target material is selected, and a ZnO seed layer thin film is prepared on a Si substrate using the sputtering assembly 103. Then, a Co / ZnO nanorod array with good dispersion is synthesized on the ZnO seed layer at a temperature of 100°C using a hydrothermal method.

[0022] Furthermore, the vacuum assembly 102 includes a vacuum component 1021 and a gas filling component 1022. Both the vacuum component 1021 and the gas filling component 1022 are arranged on the reaction container 101. The vacuum component 1021 is used to evacuate the air inside the reaction container 101, and the gas filling component 1022 is used to fill the reaction container 101 with inert gas.

[0023] In specific usage scenarios, in order to avoid other interfering factors and improve the quality of preparing the ZnO seed layer, the reaction container 101 is evacuated to a negative pressure. Under the action of pressure, in order to prevent the reaction container 101 from being subjected to excessive pressure, argon is filled into the reaction container 101 using the inflatable member 1022 to maintain the pressure difference between the inside and outside of the reaction container 101.

[0024] In a preferred embodiment, the stirrer 204 includes ultrasonic stirring or magnetic stirring.

[0025] In order to mix the solutions in the first chamber 201, the second chamber 202 and the third chamber 203 more evenly in the stirrer 204, ultrasonic stirring or magnetic stirring is selected to stir the solutions in the first chamber 201, the second chamber 202 and the third chamber 203 according to the specific application scenario.

[0026] In a specific embodiment, the high-pressure reactor 205 is provided with a support, and the support comprises a polytetrafluoroethylene support.

[0027] When preparing ZnO nanocrystals, the prepared ZnO seed layer is first placed on a bracket. In order to avoid the influence of the bracket on the preparation of ZnO nanocrystals, a polytetrafluoroethylene bracket is selected. The advantages of the polytetrafluoroethylene bracket are: a very wide operating temperature range (from -200 degrees Celsius to +260 degrees Celsius), corrosion resistance to basically all chemical substances except some fluorides and alkaline metal liquids, being classified as a flame retardant material in the air, excellent insulation properties (regardless of its frequency and temperature), extremely low water absorption, and a series of properties such as self-lubricity and non-stickiness, low friction coefficient and very good wear resistance. In this system, ZnO nanocrystals are prepared with the help of the polytetrafluoroethylene bracket.

[0028] In a preferred embodiment, the ZnO nanocrystal preparation system further includes a heating device 30, which is disposed between the ZnO seed layer preparation device 10 and the Co-doped ZnO nanorod array preparation device 20 and is used to heat the ZnO seed layer sample.

[0029] The ZnO seed layer preparation device 10 needs to perform high-temperature calcination to prepare the ZnO seed layer, so the heating device 30 is set between the ZnO seed layer preparation device 10 and the Co-doped ZnO nanorod array preparation device 20, and the ZnO seed layer is placed in a muffle furnace for treatment at a temperature of 400°C and a heating time of 3 hours.

[0030] The above disclosure is only a preferred embodiment of the present invention, and it certainly cannot be used to limit the scope of the present invention. A person skilled in the art can understand that all or part of the processes of the above embodiments and equivalent changes made according to the claims of the present invention still fall within the scope of the present invention.

Claims

1. A system for preparing ZnO nanocrystals, characterized in that: The invention comprises a ZnO seed layer preparation device and a Co-doped ZnO nanorod array preparation device, wherein the ZnO seed layer preparation device is used to prepare the ZnO seed layer, and the Co-doped ZnO nanorod array preparation device is used to prepare the ZnO seed layer into ZnO nanocrystals; the ZnO seed layer preparation device comprises a reaction container, a vacuum pumping component, a sputtering component and a reaction base, wherein the vacuum pumping component is arranged on the reaction container and is connected with the interior of the reaction container, the sputtering component and the reaction base are arranged inside the reaction container, and the sputtering component is arranged above the reaction base; The preparation device of the Co-doped ZnO nanorod array comprises a first chamber, a second chamber, a third chamber, a stirrer and a high-pressure reactor, wherein the first chamber, the second chamber and the third chamber are connected or closed to the stirrer, the stirrer is used to stir the solution, and the outlet of the stirrer is connected to the inlet of the high-pressure reactor for preparing ZnO nanocrystals.

2. The system for preparing ZnO nanocrystals according to claim 1, characterized in that: The vacuum pumping assembly includes a vacuum pump and a gas filling member, both of which are arranged on the reaction container. The vacuum pump is used to evacuate the air inside the reaction container, and the gas filling member is used to fill the reaction container with inert gas.

3. The system for preparing ZnO nanocrystals according to claim 1, characterized in that: The stirrer includes an ultrasonic stirrer or a magnetic stirrer.

4. The system for preparing ZnO nanocrystals according to claim 1, characterized in that: A support is arranged in the high-pressure reactor, and the support comprises a polytetrafluoroethylene support.

5. The system for preparing ZnO nanocrystals according to claim 1, characterized in that: The ZnO nanocrystal preparation system further comprises a heating device, which is arranged between the ZnO seed layer preparation device and the Co-doped ZnO nanorod array preparation device and is used to heat the ZnO seed layer sample.

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