Oxide target, method of manufacturing the same, and use thereof

Abstract

The application provides an oxide target material and a preparation method and application thereof, and the preparation method comprises the following steps: mixing a metal oxide, a lithium source and a solvent to obtain a lithium-containing metal oxide; and performing primary sintering, briquetting and secondary sintering on the lithium-containing metal oxide to obtain the oxide target material; the preparation method can successfully dope lithium ions in the preparation process, and the lithium-containing oxide target material is prepared, the lithium ions are not easy to be doped due to the activity, and the defects of low conductivity and low photoelectrochemical property of the oxide film prepared by magnetron sputtering are solved, and the conductivity and the photoelectrochemical property of the oxide film are significantly improved.

Description

Technical Field

[0001] This invention belongs to the field of target technology, and relates to an oxide target, its preparation method and application. Background Technology

[0002] Currently, oxide targets are mainly prepared using the photodispatch coating (PVD) method. Specifically, this method involves bombarding the target surface with ions to eject atoms from the target, and then depositing the sputtered atoms onto the substrate surface to form a film, which is called photodispatch coating.

[0003] Currently, oxide targets deposited by PVD are mostly prepared using pure metal targets or pure metal oxide targets. For example, nickel oxide targets are prepared using pure nickel targets or pure nickel oxide targets. For instance, CN 109402565A discloses a method for growing nickel oxide thin films, using a metallic nickel target as the coating target, argon as the sputtering gas, and oxygen as the reaction gas to achieve the preparation of nickel oxide thin films. However, reactive sputtering of nickel oxide targets still faces the following problems for the uniform and rapid deposition of large-area thin films in the industry: the target surface is easily "poisoned" when sputtering in a high oxygen atmosphere, it is difficult to increase the sputtering voltage and power, and the sputtering rate also decreases significantly. Furthermore, the conductivity of oxide thin films prepared with pure metal targets or pure metal oxide targets is relatively low, and the photoelectrochemical properties of the oxide film layer are not good.

[0004] To address the poor photoelectrochemical properties of oxide thin films, although lithium ions can promote the ion mobility of oxide thin films and thus improve the photoelectrochemical properties of nickel oxide thin films, lithium ions are extremely reactive and sensitive, making it difficult to dope them during the reaction process.

[0005] Based on the above research, there is a need to provide a method for preparing oxide targets. This method can successfully dope lithium, significantly improve the conductivity and photoelectrochemical performance of oxide films, and avoid the defects of manipulating sputtering methods for preparing oxide targets. Summary of the Invention

[0006] The purpose of this invention is to provide an oxide target material, its preparation method and application, particularly a lithium-containing metal oxide target material, its preparation method and application. The preparation method can successfully dope lithium ions during the preparation process to obtain a lithium-containing oxide target material, which solves the problems of lithium ions being active and difficult to incorporate, and the defects of low conductivity and photoelectrochemical properties of oxide films prepared by magnetron sputtering, and significantly improves the conductivity and photoelectrochemical properties of oxide films.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a method for preparing an oxide target, the method comprising the following steps:

[0009] (1) Mix metal oxide, lithium source and solvent to obtain lithium-containing metal oxide;

[0010] (2) The lithium-containing metal oxide described in step (1) is subjected to a first sintering, pressing and a second sintering to obtain the oxide target material.

[0011] This invention uses a mixed sintering method to prepare the target material and successfully incorporates lithium during the preparation process. The entire preparation process is simple and the reaction conditions are easy to control, avoiding the problem that lithium ions cannot be incorporated during the reaction due to their high activity. This significantly improves the conductivity of the oxide target material, thereby enhancing its photochemical performance. Furthermore, in step (1) of this invention, the oxide, lithium source, and solvent are directly mixed and sintered before pressing, which promotes the incorporation of lithium ions, improves the lithium ion doping effect, and results in high uniformity and stability of the doping.

[0012] Preferably, the mixing in step (1) includes: adding a solvent to a mixture of metal oxide and lithium source to obtain a wet mixture, grinding the wet mixture to dry, and obtaining the lithium-containing metal oxide.

[0013] Preferably, the addition of solvent yields a wet mixture, and the wet mixture is ground to dryness 3-5 times, for example, 3, 4 or 5 times.

[0014] The present invention employs a solvent-assisted grinding method to mix metal oxides and lithium sources. Adding solvent to the grinding process can result in a finer particle size distribution and higher grinding efficiency. The liquid in the wet grinding process can act as a lubricant and coolant, which helps to reduce friction and heat accumulation during grinding, thereby improving grinding efficiency and grinding quality. Furthermore, by repeatedly wet grinding to dry, lithium incorporation can be promoted, the mixing uniformity can be improved, and the metallic lithium can be passivated, thus enabling the successful incorporation of lithium during the preparation process.

[0015] Preferably, the mass ratio of the solvent added each time to the metal oxide is (0.5-2):10, for example, it can be 0.5:10, 1:10, 1.5:10 or 2:10, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0016] The amount of solvent added in this invention, within a reasonable range, can further promote lithium doping. If too much solvent is added, it will reduce particle dispersibility and stability, thereby affecting the grinding effect. In addition, too much solvent will also increase the consumption of grinding fluid and increase production costs. If too little solvent is added, the viscosity of the grinding fluid will become very high, which will easily lead to particle aggregation and a poor grinding effect. At the same time, too little solvent will also raise the temperature of the grinding fluid, accelerating particle wear and breakage, thereby affecting the quality of the material.

[0017] Preferably, the mass ratio of lithium source to metal oxide in step (1) is (0.0005-0.005):10, for example, it can be 0.0005:10, 0.001:10 or 0.005:10, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0018] Preferably, the lithium source includes lithium powder.

[0019] This invention directly uses lithium powder for doping. Lithium is a highly active metal with high doping efficiency in materials, which can effectively change the electrical properties of materials. Furthermore, lithium powder is a common metal powder with a relatively low price. Directly using lithium powder for doping can reduce the material preparation cost. Compared with other doping methods, direct doping with lithium powder does not require complex equipment, is simple and quick to operate, and is suitable for small-batch preparation. By controlling parameters such as the amount of lithium powder added and the doping temperature, uniform doping of materials can be achieved, thereby improving the stability and performance of the materials.

[0020] Preferably, the metal oxide in step (1) includes nickel oxide and / or tungsten oxide.

[0021] Preferably, the solvent in step (1) includes any one or a combination of at least two of ethanol, acetone or tetrahydrofuran, with ethanol being the most preferred.

[0022] The preferred solvent for grinding in this invention is ethanol. Compared with other organic solvents, ethanol has lower toxicity and lower volatility, posing less harm to operators and is safer. Moreover, as a mild solvent, ethanol will not cause excessive damage to the surface of the grinding material, effectively protecting the properties of the grinding material. Finally, ethanol can be quickly removed by heating and evaporation, without causing significant environmental pollution.

[0023] Preferably, the purity of the metal oxide in step (1) is >99.9%, for example, it can be 99.91%, 99.95% or 99.99%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0024] Preferably, the purity of the lithium source in step (1) is >99.9%, for example, it can be 99.91%, 99.95% or 99.99%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0025] Preferably, the purity of the solvent in step (1) is >99.9%, for example, it can be 99.91%, 99.95% or 99.99%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0026] Preferably, after the first sintering in step (2) and before pressing, grinding is also performed.

[0027] The present invention further involves thorough grinding after sintering, so that the lithium-containing metal oxide after the first sintering is in powder form, which promotes the subsequent preparation of thin films.

[0028] Preferably, the temperature of the first sintering in step (2) is 200-400℃, for example, 200℃, 300℃ or 400℃, the time is 0.5-1.5h, for example, 0.5h, 1h or 1.5h, and the heating rate is 4-6℃ / min, for example, 4℃ / min, 5℃ / min or 6℃ / min, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0029] Preferably, the atmosphere for the first sintering includes an air atmosphere.

[0030] Preferably, the pressing block in step (2) includes pre-pressing and hydraulic pressing performed sequentially.

[0031] Before hydraulicing, the present invention performs pre-compression, which can improve the sealing performance of the powder object by pre-compressing it into a block shape. This is because the powder object can form a denser structure during the pre-compression process, and its shape and size can be adjusted as needed, which can improve the photochemical performance of the obtained oxide target film.

[0032] Preferably, the pre-compression pressure is 15-35 kPa, for example, 15 kPa, 20 kPa, 30 kPa or 35 kPa, and the time is 0.5-2 min, for example, 0.5 min, 1 min, 1.5 min or 2 min, but not limited to the listed values, other unlisted values ​​within the range are also applicable.

[0033] Preferably, the hydraulic pressure includes vacuum sealing the pre-pressed module under a pressure of 40-60 kPa, for example, 40 kPa, 50 kPa or 60 kPa, for 1-3 minutes, for example, 1 minute, 2 minutes or 3 minutes, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0034] Preferably, the secondary sintering temperature in step (2) is 800-1000℃, for example, 800℃, 900℃ or 1000℃, the time is 8-12h, for example, 8h, 9h, 10h, 11h or 12h, and the heating rate is 3-8℃ / min, for example, 3℃ / min, 4℃ / min, 5℃ / min, 6℃ / min, 7℃ / min or 8℃ / min, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0035] Preferably, the atmosphere for the secondary sintering includes an air atmosphere.

[0036] As a preferred method of the preparation method described in this invention, the preparation method includes the following steps:

[0037] (1) Add solvent to the mixture of metal oxide and lithium source to obtain a wet mixture. Grind the wet mixture until dry. Repeat the addition of solvent and grinding of the wet mixture until dry 3-5 times to obtain a lithium-containing metal oxide.

[0038] The mass ratio of the solvent added each time to the metal oxide is (0.5-2):10, and the mass ratio of the lithium source to the metal oxide is (0.0005-0.005):10.

[0039] The lithium source includes lithium powder, the metal oxide includes nickel oxide and / or tungsten oxide, and the solvent includes any one or a combination of at least two of ethanol, acetone or tetrahydrofuran.

[0040] (2) The lithium-containing metal oxide described in step (1) is sintered in air at a temperature of 200-400°C for 0.5-1.5 hours with a heating rate of 4-6°C / min. After cooling, it is ground to obtain a sintered material.

[0041] (3) The sintering material described in step (2) is pre-pressed at a pressure of 15-35KPa for 0.5-2min, and the resulting module is vacuum-sealed. Then, it is hydraulically compressed at a pressure of 40-60KPa for 1-3min to obtain the formed module.

[0042] (4) In an air atmosphere, at a heating rate of 3-8℃ / min and a temperature of 800-1000℃, the module formed in step (3) is sintered for 8-12 hours to obtain the oxide target material.

[0043] In a second aspect, the present invention provides an oxide target material, which is prepared by the preparation method described in the first aspect.

[0044] Thirdly, the present invention provides an application of the oxide target as described in the second aspect, the application including its use in the field of electrochromism.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] This invention uses a mixed sintering method to prepare the target material. Compared with the magnetron sputtering method, it can successfully incorporate lithium during the preparation process. The entire preparation process is simple and the reaction conditions are easy to control. It avoids the problem that lithium ions cannot be incorporated during the reaction process due to their high reactivity. This significantly improves the conductivity of the oxide target material, thereby enhancing its photochemical performance. Detailed Implementation

[0047] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0048] Example 1

[0049] This embodiment provides a method for preparing a nickel oxide target, the method comprising the following steps:

[0050] (1) Grind and mix 10g of nickel oxide with a purity of 99.99% and 1mg of lithium source with a purity of 99.99% to obtain a mixture. Add solvent to the obtained mixture to obtain a wet mixture. Grind the wet mixture until dry. Repeat adding solvent and grinding the wet mixture until dry 3 times to obtain nickel oxide containing lithium.

[0051] The solvent is ethanol with a purity of 99.99%, and the mass ratio of the solvent added each time to nickel oxide is 1:10; the lithium source is lithium powder, and the mass ratio of the lithium source to nickel oxide is 0.001:10.

[0052] (2) The lithium-containing nickel oxide described in step (1) is sintered in air at a temperature of 300°C for 1 hour at a heating rate of 5°C / min. After cooling, it is ground to obtain a sintered material.

[0053] (3) The sintering material described in step (2) is pre-pressed at 25 kPa for 1 min, the resulting module is placed in a plastic bag, vacuum sealed, sealed with two layers of plastic bags, placed in a hydraulic cylinder, hydraulic oil is added, the hydraulic mold is assembled, and hydraulic pressure is applied at 50 kPa for 2 min to obtain the formed module.

[0054] (4) In an air atmosphere, at a heating rate of 5℃ / min and a temperature of 900℃, the module formed in step (3) is sintered for 10 hours to obtain the nickel oxide target.

[0055] Example 2

[0056] This embodiment provides a method for preparing a nickel oxide target, the method comprising the following steps:

[0057] (1) Grind and mix nickel oxide with a purity of 99.99% and lithium source with a purity of 99.95% to obtain a mixture. Add solvent to the obtained mixture to obtain a wet mixture. Grind the wet mixture until dry. Repeat adding solvent and grinding the wet mixture until dry twice to obtain nickel oxide containing lithium.

[0058] The solvent is ethanol with a purity of 99.95%, and the mass ratio of the solvent added each time to nickel oxide is 0.5:10; the lithium source is lithium powder, and the mass ratio of the lithium source to nickel oxide is 0.0005:10.

[0059] (2) The lithium-containing nickel oxide described in step (1) is sintered in air at a heating rate of 4℃ / min and a temperature of 400℃ for 0.5h. After cooling, it is ground to obtain a sintered material.

[0060] (3) The sintering material described in step (2) is pre-pressed at 15KPa for 2 minutes. The resulting module is placed in a plastic bag, vacuum sealed, sealed with two layers of plastic bags, placed in a hydraulic cylinder, hydraulic oil is added, the hydraulic mold is assembled, and hydraulic pressure is applied at 60KPa for 1 minute to obtain the formed module.

[0061] (4) In an air atmosphere, at a heating rate of 8℃ / min and a temperature of 1000℃, the module formed in step (3) is sintered for 8 hours to obtain the nickel oxide target.

[0062] Example 3

[0063] This embodiment provides a method for preparing a nickel oxide target, the method comprising the following steps:

[0064] (1) Grind and mix nickel oxide with a purity of 99.91% and lithium source with a purity of 99.91% to obtain a mixture. Add solvent to the obtained mixture to obtain a wet mixture. Grind the wet mixture until dry. Repeat adding solvent and grinding the wet mixture until dry 5 times to obtain nickel oxide containing lithium.

[0065] The solvent is acetone with a purity of 99.91%, and the mass ratio of the solvent added each time to nickel oxide is 2:10; the lithium source is lithium powder, and the mass ratio of the lithium source to nickel oxide is 0.005:10.

[0066] (2) The lithium-containing nickel oxide described in step (1) is sintered in air at a heating rate of 6°C / min and a temperature of 200°C for 1.5 hours. After cooling, it is ground to obtain a sintered material.

[0067] (3) The sintering material described in step (2) is pre-pressed at 35KPa for 0.5min, the resulting module is placed in a plastic bag, vacuum sealed, sealed with two layers of plastic bags, placed in a hydraulic cylinder, hydraulic oil is added, the hydraulic mold is assembled, and hydraulic pressure is applied at 40KPa for 3min to obtain the formed module.

[0068] (4) In an air atmosphere, at a heating rate of 3℃ / min and a temperature of 800℃, the module formed in step (3) is sintered for 12 hours to obtain the nickel oxide target.

[0069] Example 4

[0070] This embodiment provides a method for preparing tungsten oxide target material. The preparation method is the same as in Example 1, except that nickel oxide is replaced by tungsten oxide.

[0071] Example 5

[0072] This embodiment provides a method for preparing a nickel oxide target. Except for the lithium source in step (1) being lithium carbonate, the preparation method is the same as in Example 1.

[0073] Example 6

[0074] This embodiment provides a method for preparing a nickel oxide target. Except for the lithium source in step (1) being lithium hydroxide, the preparation method is the same as in Example 1.

[0075] Example 7

[0076] This embodiment provides a method for preparing a nickel oxide target. Except for step (1), where the mass ratio of the solvent added each time to nickel oxide is 0.1:10, the preparation method is the same as in Example 1.

[0077] Example 8

[0078] This embodiment provides a method for preparing a nickel oxide target. Except for step (1), where the ratio of the amount of solvent added each time to the mass of nickel oxide is 4:10, the preparation method is the same as in Example 1.

[0079] Example 9

[0080] This embodiment provides a method for preparing a nickel oxide target. Except for the solvent in step (1), which is acetone, the preparation method is the same as in Example 1.

[0081] Example 10

[0082] This embodiment provides a method for preparing a nickel oxide target. Except for the solvent in step (1) being tetrahydrofuran, the preparation method is the same as in Example 1.

[0083] Example 11

[0084] This embodiment provides a method for preparing a nickel oxide target. Except for step (3), which does not involve pre-pressing, the preparation method is the same as in Example 1.

[0085] Comparative Example 1

[0086] This comparative example provides a method for preparing a nickel oxide target. The preparation method is the same as that in Example 1, except that no solvent is added in step (1).

[0087] Comparative Example 2

[0088] This comparative example provides a method for preparing a nickel oxide target, which is the same as that in Example 1 except that step (2) is not performed.

[0089] The conductivity of the target material obtained in the above embodiments and comparative examples was tested, and the electrochromic coloring and fading time were tested under applied voltages of +3V and -2V.

[0090] The test results are shown in the table below:

[0091] Table 1

[0092]

[0093]

[0094] As can be seen from the table above:

[0095] The oxide target material prepared by the method described in this invention has high electrical conductivity and photochemical properties. As can be seen from Example 1 and Comparative Examples 1-2, the solvent-assisted grinding and mixing, and the single sintering after grinding, can promote the incorporation of lithium and avoid the problem that lithium ions are too active and difficult to incorporate during the preparation process. As can be seen from Example 1 and Examples 5-10, the type of lithium source, the amount of solvent added during grinding, and the type of solvent all affect the incorporation of lithium. As can be seen from Example 1 and Example 11, the pre-pressing treatment performed before hydraulic preparation of the target material can further improve the photochemical properties of the target material.

[0096] In summary, this invention provides an oxide target material, its preparation method, and its application. The preparation method can successfully dope lithium ions during the preparation process to obtain a lithium-containing oxide target material, which solves the problems of lithium ions being active and difficult to incorporate, as well as the defects of low conductivity and photoelectrochemical properties of oxide films prepared by magnetron sputtering, and significantly improves the conductivity and photoelectrochemical properties of oxide films.

[0097] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method of producing an oxide target material, characterized by, The preparation method includes the following steps: (1) Mix metal oxide, lithium source and solvent to obtain lithium-containing metal oxide; (2) The lithium-containing metal oxide described in step (1) is subjected to a first sintering, pressing, and a second sintering to obtain the oxide target material; The mixing in step (1) includes: adding a solvent to the mixture of metal oxide and lithium source to obtain a wet mixture, grinding the wet mixture to dry, and obtaining the lithium-containing metal oxide; the number of times the solvent is added to obtain a wet mixture and the wet mixture is ground to dry is 3-5 times; the mass ratio of the amount of solvent added each time to the mass of the metal oxide is (0.5-2):10; The metal oxide in step (1) includes nickel oxide and / or tungsten oxide; The lithium source mentioned in step (1) is lithium powder; The purity of the lithium source mentioned in step (1) is >99.9%; The solvent in step (1) is ethanol; The pressing block in step (2) includes pre-pressing and hydraulic pressing performed sequentially.

2. The production method according to claim 1, characterized by, The mass ratio of lithium source and metal oxide in step (1) is (0.0005-0.005):

10.

3. The preparation method according to claim 1, characterized in that, The purity of the metal oxide in step (1) is >99.9%.

4. The preparation method according to claim 1, characterized in that, The purity of the solvent in step (1) is >99.9%.

5. The preparation method according to claim 1, characterized in that, After the first sintering described in step (2), grinding was also performed before pressing the blocks.

6. The preparation method according to claim 1, characterized in that, The temperature of the first sintering in step (2) is 200-400℃, the time is 0.5-1.5h, and the heating rate is 4-6℃ / min.

7. The preparation method according to claim 1, characterized in that, The atmosphere for the first sintering in step (2) includes an air atmosphere.

8. The preparation method according to claim 1, characterized in that, The pre-compression pressure is 15-35 kPa, and the time is 0.5-2 min.

9. The preparation method according to claim 1, characterized in that, The hydraulic process includes vacuum sealing the pre-compressed module and applying hydraulic pressure for 1-3 minutes at a pressure of 40-60 kPa.

10. The preparation method according to claim 1, characterized in that, The secondary sintering temperature in step (2) is 800-1000℃, the time is 8-12h, and the heating rate is 3-8℃ / min.

11. The preparation method according to claim 1, characterized in that, The atmosphere for the secondary sintering in step (2) includes an air atmosphere.

12. The preparation method according to claim 1, characterized in that, The preparation method includes the following steps: (1) Add solvent to the mixture of metal oxide and lithium source to obtain a wet mixture. Grind the wet mixture until dry. Repeat the addition of solvent and grinding of the wet mixture until dry 3-5 times to obtain a lithium-containing metal oxide. The mass ratio of the solvent added each time to the metal oxide is (0.5-2):10, and the mass ratio of the lithium source to the metal oxide is (0.0005-0.005):

10. (2) The lithium-containing metal oxide described in step (1) is sintered in air at a temperature of 200-400°C for 0.5-1.5 hours with a heating rate of 4-6°C / min. After cooling, it is ground to obtain a sintered material. (3) The sintering material described in step (2) is pre-pressed at a pressure of 15-35KPa for 0.5-2min, and the resulting module is vacuum-sealed. Then, it is hydraulically compressed at a pressure of 40-60KPa for 1-3min to obtain the formed module. (4) In an air atmosphere, at a heating rate of 3-8℃ / min and a temperature of 800-1000℃, the shaped module formed in step (3) is sintered for 8-12 hours to obtain the oxide target material.

13. An oxide target material, characterized in that, The oxide target material is prepared by the preparation method described in any one of claims 1-12.

14. An application of the oxide target material as described in claim 13, characterized in that, The applications include those for electrochromic applications.

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