Production method of large-size nickel oxide planar target

Abstract

The invention belongs to the technical field of target materials, and particularly relates to a production method of a large-size nickel oxide planar target, which comprises the following steps: S1, injecting slurry containing nickel oxide into a mold, and drying to obtain a primary blank; s2, degumming the primary green body, and pre-sintering the primary green body in an oxygen-free atmosphere; s3, crushing and sieving the pre-sintered primary green body to obtain powder, adding a binder, uniformly mixing, granulating, sieving, and carrying out cold isostatic pressing to obtain a secondary green body; s4, the secondary blank is heated and sintered, and the large-size nickel oxide planar target is obtained; the large-size nickel oxide planar target prepared by the preparation method disclosed by the invention has relatively low resistivity and relatively high relative density.

Description

Technical Field

[0001] The invention belongs to the technical field of target materials, and in particular relates to a production method of a large-size nickel oxide planar target. Background Art

[0002] Currently, perovskite solar cells are one of the important directions of the future photovoltaic industry. Due to their high theoretical conversion efficiency and their ability to be stacked with crystalline silicon solar cells, they have become a research hotspot in the photovoltaic field. Perovskite solar cells are usually composed of multiple functional layers, among which the hole transport layer plays a vital role. Nickel oxide film has become an ideal material for preparing the hole transport layer due to its good electrical properties, chemical stability and compatibility with perovskite materials.

[0003] Magnetron sputtering is an efficient physical vapor deposition technology used in thin film preparation and surface modification. Through this method, the desired thin film can be accurately deposited on the substrate using nickel oxide targets. The quality of the sputtering target plays a vital role in the quality of the film. In order to achieve the desired film properties, factors such as the density and grain size of the target must be precisely adjusted.

[0004] A Chinese patent application document with publication number CN116768606A discloses a method for preparing a composite nickel-magnesium oxide target. The application document prepares a composite nickel-magnesium oxide target using NiO powder and MgO powder as raw materials. The process of ball milling and molding in the preparation of the target is mainly adjusted. The preparation method is simple and the composite nickel-magnesium oxide target is relatively uniform; however, the maximum relative density of the obtained target is only 98.5%. At the same time, this method dopes a relatively high magnesium element in the target, which is likely to cause lattice expansion and may cause the target to crack. Summary of the invention

[0005] The existing nickel oxide target material has the problems of low density and easy cracking. In order to solve this problem, the present invention provides a method for producing a large-size nickel oxide planar target.

[0006] In order to achieve the purpose of the present invention, the present invention adopts the following technical solutions: The present invention provides a method for producing a large-size nickel oxide planar target, comprising the following steps: S1: injecting a slurry containing nickel oxide into a mold and drying it to obtain a primary green body; S2: After the primary green body is debonded, it is pre-sintered in an oxygen-free atmosphere; S3: crushing the pre-sintered primary green body, sieving to obtain powder, adding a binder and mixing evenly, granulating, sieving, and cold isostatic pressing to obtain a secondary green body; S4: The secondary green body is heated and sintered to obtain a large-sized nickel oxide planar target.

[0007] Preferably, in step S1, the method for preparing the slurry containing nickel oxide comprises the following steps: (1) Mix the organic monomer, cross-linking agent and water evenly, and adjust the pH to 8-10 to obtain a mixed solution A; (2) uniformly mixing nickel oxide, sintering aid, additives and water to obtain a mixed solution B; (3) Mix the mixed solution A and the mixed solution B to obtain a premix, add an initiator and a catalyst and mix them to obtain a slurry containing nickel oxide.

[0008] Preferably, the mass ratio of the organic monomer to the nickel oxide is (0.015-0.04):1.

[0009] By adopting the above technical solution, under this ratio, the gel forms a uniform network structure around the nickel oxide, tightly fixes the nickel oxide together during the polymerization process, so that the shape of the green body is well maintained and the damage of the green body during demoulding is reduced.

[0010] Preferably, in step (1), the mass ratio of the organic monomer to the cross-linking agent is 1:(0.1-0.2).

[0011] By adopting the above technical solution, under this ratio, the three-dimensional network structure formed by cross-linking of organic monomers can maintain the size and shape of large-sized targets, making the blank less likely to deform during demolding, drying and subsequent processing.

[0012] Preferably, in step (1), the organic monomer is one of methacrylamide and ethyl methacrylate, and the cross-linking agent is N,N'-methylenebisacrylamide.

[0013] Preferably, in step (2), the mass ratio of nickel oxide to sintering aid is 1:(0.01-0.03).

[0014] Preferably, in step (2), the sintering aid is composed of cadmium oxide and samarium oxide in a mass ratio of (2-4):1.

[0015] By adopting the above technical solution, under this ratio, the sintering aid can form a liquid phase, reduce the sintering temperature, increase the diffusion and sintering speed, and help achieve densification at a relatively low temperature.

[0016] Preferably, in step (2), the amount of the additive is 0.5%-1.5% of the mass of nickel oxide.

[0017] Preferably, in step (2), the additive is polyvinyl pyrrolidone, diglycolamine and hydroxymethyl cellulose in a mass ratio of (5-8) : 1 : (2-4).

[0018] By adopting the above technical solution, the dispersion stability of nickel oxide is optimized under this ratio of the three, and the sedimentation and agglomeration of nickel oxide are effectively prevented.

[0019] Preferably, in step (2), the uniform mixing includes ultrasonic dispersion and ball milling, as follows: The ultrasonic dispersion time is 20-30 min.

[0020] By adopting the above technical solution, within this time range, ultrasonic dispersion can fully play its role, effectively break up the agglomeration between nickel oxides, and make the nickel oxide evenly dispersed.

[0021] The ball milling speed is 400-800 rpm, and the ball milling time is 10-15 h.

[0022] By adopting the above technical solution, within the time range, the nickel oxide is sufficiently crushed and refined, the nickel oxide particle size distribution is uniform, and the dispersion effect is good.

[0023] Preferably, in step (3), the initiator is benzoyl peroxide; and the catalyst is N,N-dimethylacetamide.

[0024] Preferably, in step S1, the specific steps of drying are as follows: drying in a vacuum oven at 40-50°C for 5-8h, demoulding, and further drying in a vacuum oven at 70-80°C for 8-12h.

[0025] Preferably, in step S2, the specific steps of the degumming treatment are as follows: sintering at 500-600°C under normal pressure, with a heating rate of 1-2°C / min, a heat preservation time of 5-8h, and cooling to room temperature with the furnace.

[0026] Preferably, in step S2, the specific steps of pre-sintering are as follows: sintering the primary green body at normal pressure at a temperature of 850-900°C, a heating rate of 3-5°C / min, a holding time of 3-5h, and cooling to room temperature with the furnace.

[0027] Preferably, in step S3, the binder is selected from polyvinyl alcohol and polyethylene glycol.

[0028] Preferably, in step S4, the temperature rising sintering includes first stage sintering and second stage sintering, which are specifically as follows: during the first stage sintering process, neon gas is introduced, the sintering temperature is 500-800°C, the heating rate is 0.5-1.5°C / min, the insulation time is 3-8h, and the sintering pressure is 20-80Pa; during the second stage sintering process, oxygen is introduced, the sintering temperature is 1250-1400°C, the heating rate is 3-5°C / min, the sintering time is 8-20h, the sintering pressure is 200-500Pa, and the insulation time is 2-8h; the heating rate from the first stage sintering temperature to the second stage sintering temperature is 2°C / min.

[0029] By adopting the above-mentioned technical means, the introduction of oxygen during the second stage of sintering can enable the grains to grow more evenly, reduce the difference in grain size, and make the structure of the target material more uniform and dense; at the same time, it can promote the uniform growth of grains and reduce lattice defects, making the electron transmission channel inside the target material smoother, thereby improving conductivity.

[0030] In summary, the beneficial effects of the present invention are: (1) The present invention adopts gel injection molding for the first time, so that the raw material powder can be evenly dispersed in the gel system to form a primary green body with a relatively uniform internal structure; isostatic pressing is used as a secondary molding method, which can apply isotropic pressure to the green body, so that the green body is evenly compacted in all directions, which can effectively improve the density and density uniformity of the green body; the primary green body has a faster densification rate after pre-sintering, and its grain size is more uniform; (2) The present invention uses polyvinyl pyrrolidone, diglycolamine and hydroxymethyl cellulose to modify the surface of nickel oxide, and generates an isolation layer on the surface of nickel oxide particles, which is beneficial to improving the uniformity of the internal structure of the target material, and utilizing steric hindrance to avoid local density differences and defects caused by powder agglomeration, thereby improving the performance stability of the target material; (3) The present invention uses nickel oxide as the main component, and cadmium oxide and samarium oxide as sintering aids. A small amount of liquid phase can be formed during the sintering stage, which promotes particle rearrangement and pore filling, reduces defects such as pores and cracks, and improves the density and hardness of the target material; cadmium oxide can improve the carrier mobility after adjustment of the coating, reduce resistance, and improve electrical properties; (4) The large-sized nickel oxide planar target prepared by the present invention has a single piece length of 500-1000 mm, a width of 100-200 mm, and a thickness of 5-10 mm, and has a lower resistivity and a higher relative density. DETAILED DESCRIPTION

[0031] The technical solution of the present invention is explained in detail below with reference to several representative embodiments of the present invention.

[0032] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, etc. used in the following examples are all commercially available unless otherwise specified.

[0033] The nickel oxide used in the present invention has an average particle size of 250nm and a purity of ≥99.99%; The average particle size of the cadmium oxide used in the present invention is 200nm, and the purity is ≥99.99%; The average particle size of the samarium oxide used in the present invention is 200nm, and the purity is ≥99.99%.

[0034] Example 1 The production method of a large-size nickel oxide planar target in this embodiment has the following specific steps: S1: injecting the slurry containing nickel oxide into the mold, drying it in a vacuum oven at 40°C for 6 hours, demoulding, and further drying it in a vacuum oven at 70°C for 8 hours to obtain a primary green body; S2: In a neon atmosphere, the primary green body is sintered at 550°C under normal pressure, the heating rate is 1°C / min, the holding time is 8 hours, and the green body is cooled to room temperature with the furnace to obtain a primary green body after debinding treatment; In a neon atmosphere, the primary green body after debinding treatment is sintered under normal pressure at a temperature of 900°C, the heating rate is 4°C / min, the holding time is 5 hours, and the green body is cooled to room temperature with the furnace to obtain a primary green body after pre-sintering; S3: The pre-sintered primary green body was crushed and passed through a 100-mesh sieve to obtain powder, 10% polyvinyl alcohol by mass was added and ball-milled in a ball mill at 400 rpm for 6 h, granulated using a spray dryer, passed through a 150-mesh sieve, and pressed into shape using a cold isostatic press at 200 MPa to obtain a secondary green body; S4: The secondary green body is transferred to a sintering furnace for sintering. During the first stage of sintering, neon gas is introduced. The sintering temperature is 800°C, the heating rate is 1.5°C / min, the holding time is 4 hours, and the sintering pressure is 80Pa. The heating rate from the first stage sintering temperature to the second stage sintering temperature is 2°C / min. During the second stage of sintering, oxygen is introduced. The sintering temperature is 1250°C, the heating rate is 5°C / min, the sintering time is 20 hours, the sintering pressure is 500Pa, and the holding time is 5 hours. The green body is cooled to room temperature with the furnace to obtain a large-sized nickel oxide flat target.

[0035] The method for preparing the slurry containing nickel oxide in this embodiment comprises the following specific steps: (1) Mix 3 g of methacrylamide, 0.3 g of N,N'-methylenebisacrylamide and 90 g of water, stir for 30 min, and adjust the pH to 8 to obtain a mixed solution A; (2) Mix 100 g of nickel oxide, 1.5 g of cadmium oxide, 0.5 g of samarium oxide, 1 g of polyvinyl pyrrolidone, 0.125 g of diglycolamine, 0.375 g of hydroxymethyl cellulose and 60 g of water, disperse by ultrasonic for 25 min, transfer to a ball mill and mill at 600 rpm for 12 h to obtain a mixed solution B; (3) Mixing the mixed solution A and the mixed solution B, ultrasonically dispersing for 30 minutes to obtain a premix, adding 0.5 g of benzoyl peroxide and 0.08 g of N,N-dimethylacetamide and ultrasonically dispersing for 10 minutes to obtain a slurry containing nickel oxide.

[0036] Example 2 The production method of a large-size nickel oxide planar target in this embodiment has the following specific steps: S1: injecting the slurry containing nickel oxide into the mold, drying it in a vacuum oven at 40°C for 8 hours, demoulding, and further drying it in a vacuum oven at 80°C for 12 hours to obtain a primary green body; S2: In a neon atmosphere, the primary green body is sintered at 600°C under normal pressure, with a heating rate of 1.5°C / min and a holding time of 8h, and then cooled to room temperature with the furnace to obtain a primary green body after debonding treatment; In a neon atmosphere, the primary green body after debonding treatment is sintered under normal pressure at a temperature of 850°C, a heating rate of 3°C / min and a holding time of 4h, and then cooled to room temperature with the furnace to obtain a primary green body after pre-sintering; S3: The pre-sintered primary green body is crushed and passed through a 100-mesh sieve to obtain powder, polyvinyl alcohol is added and ball-milled in a ball mill at 400 rpm for 6 h, granulated using a spray dryer, passed through a 150-mesh sieve, and pressed into shape using a cold isostatic press at 200 MPa to obtain a secondary green body; S4: The secondary green body is transferred to a sintering furnace for sintering. During the first stage of sintering, neon gas is introduced, the sintering temperature is 500°C, the heating rate is 1°C / min, the holding time is 6 hours, and the sintering pressure is 20Pa; the heating rate from the first stage sintering temperature to the second stage sintering temperature is 2°C / min; during the second stage of sintering, oxygen is introduced, the sintering temperature is 1300°C, the heating rate is 3°C / min, the sintering time is 10 hours, the sintering pressure is 300Pa, the holding time is 2 hours, and the green body is cooled to room temperature with the furnace to obtain a large-sized nickel oxide flat target.

[0037] The method for preparing the slurry containing nickel oxide in this embodiment comprises the following specific steps: (1) Mix 1.5 g of methacrylamide, 0.3 g of N,N'-methylenebisacrylamide and 90 g of water, stir for 30 min, and adjust the pH to 9 to obtain a mixed solution A; (2) 100 g nickel oxide, 2 g cadmium oxide, 1 g samarium oxide, 0.5 g polyvinyl pyrrolidone, 0.1 g diglycolamine, 0.2 g hydroxymethyl cellulose and 60 g water were mixed, ultrasonically dispersed for 30 min, and transferred to a ball mill for ball milling at 800 rpm for 15 h to obtain a mixed solution B; (3) Mixing the mixed solution A and the mixed solution B, ultrasonically dispersing for 30 minutes to obtain a premix, adding 0.5 g of benzoyl peroxide and 0.08 g of N,N-dimethylacetamide and ultrasonically dispersing for 10 minutes to obtain a slurry containing nickel oxide.

[0038] Example 3 The production method of a large-size nickel oxide planar target in this embodiment has the following specific steps: S1: injecting the slurry containing nickel oxide into the mold, drying it in a vacuum oven at 45°C for 5 hours, demoulding, and further drying it in a vacuum oven at 75°C for 12 hours to obtain a primary green body; S2: In a neon atmosphere, the primary green body is sintered at 500°C under normal pressure, with a heating rate of 2°C / min and a holding time of 5h, and then cooled to room temperature with the furnace to obtain a primary green body after debonding treatment; In a neon atmosphere, the primary green body after debonding treatment is sintered under normal pressure at a temperature of 880°C, a heating rate of 3.5°C / min and a holding time of 3h, and then cooled to room temperature with the furnace to obtain a primary green body after pre-sintering; S3: The pre-sintered primary green body is crushed and passed through a 100-mesh sieve to obtain powder, polyethylene glycol is added and ball-milled in a ball mill at a speed of 400 rpm for 6 h, granulated using a spray dryer, passed through a 150-mesh sieve, and pressed into shape using a cold isostatic press at 200 MPa to obtain a secondary green body; S4: The secondary green body is transferred to a sintering furnace for sintering. During the first stage of sintering, neon gas is introduced, the sintering temperature is 600°C, the heating rate is 0.5°C / min, the holding time is 3h, and the sintering pressure is 50Pa; the heating rate from the first stage sintering temperature to the second stage sintering temperature is 2°C / min; during the second stage of sintering, oxygen is introduced, the sintering temperature is 1400°C, the heating rate is 4°C / min, the sintering time is 8h, the sintering pressure is 200Pa, the holding time is 6h, and the green body is cooled to room temperature with the furnace to obtain a large-sized nickel oxide flat target.

[0039] The method for preparing the slurry containing nickel oxide in this embodiment comprises the following specific steps: (1) Mix 2 g of ethyl methacrylate, 0.4 g of N,N'-methylenebisacrylamide and 90 g of water, stir for 30 min, and adjust the pH to 10 to obtain a mixed solution A; (2) 100 g of nickel oxide, 0.75 g of cadmium oxide, 0.25 g of samarium oxide, 0.6 g of polyvinyl pyrrolidone, 0.1 g of diglycolamine, 0.3 g of hydroxymethyl cellulose and 60 g of water were mixed, ultrasonically dispersed for 30 min, and transferred to a ball mill and ball milled at 400 rpm for 10 h to obtain a mixed solution B; (3) Mixing the mixed solution A and the mixed solution B, ultrasonically dispersing for 30 minutes to obtain a premix, adding 0.5 g of benzoyl peroxide and 0.08 g of N,N-dimethylacetamide and ultrasonically dispersing for 10 minutes to obtain a slurry containing nickel oxide.

[0040] Example 4 The production method of a large-size nickel oxide planar target in this embodiment has the following specific steps: S1: injecting the slurry containing nickel oxide into the mold, drying it in a vacuum oven at 50°C for 8 hours, demoulding, and further drying it in a vacuum oven at 75°C for 10 hours to obtain a primary green body; S2: In a neon atmosphere, the primary green body is sintered at 600°C under normal pressure, with a heating rate of 1.5°C / min and a holding time of 7h, and then cooled to room temperature with the furnace to obtain a primary green body after debonding treatment; In a neon atmosphere, the primary green body after debonding treatment is sintered under normal pressure at a temperature of 900°C, a heating rate of 5°C / min and a holding time of 5h, and then cooled to room temperature with the furnace to obtain a primary green body after pre-sintering; S3: The pre-sintered primary green body is crushed and passed through a 100-mesh sieve to obtain powder, polyethylene glycol is added and ball-milled in a ball mill at a speed of 400 rpm for 6 h, granulated using a spray dryer, passed through a 150-mesh sieve, and pressed into shape using a cold isostatic press at 200 MPa to obtain a secondary green body; S4: The secondary green body is transferred to a sintering furnace for sintering. During the first stage of sintering, neon gas is introduced. The sintering temperature is 700°C, the heating rate is 1°C / min, the holding time is 8 hours, and the sintering pressure is 40Pa. The heating rate from the first stage sintering temperature to the second stage sintering temperature is 2°C / min. During the second stage of sintering, oxygen is introduced. The sintering temperature is 1350°C, the heating rate is 3°C / min, the sintering time is 15 hours, the sintering pressure is 350Pa, and the holding time is 8 hours. The green body is cooled to room temperature with the furnace to obtain a large-sized nickel oxide flat target.

[0041] The method for preparing the slurry containing nickel oxide in this embodiment comprises the following specific steps: (1) Mix 4 g of ethyl methacrylate, 0.6 g of N,N'-methylenebisacrylamide and 90 g of water, stir for 30 min, and adjust the pH to 10 to obtain a mixed solution A; (2) 100 g nickel oxide, 2.4 g cadmium oxide, 0.6 g samarium oxide, 0.35 g polyvinyl pyrrolidone, 0.05 g diglycolamine, 0.1 g hydroxymethyl cellulose and 60 g water were mixed, ultrasonically dispersed for 20 min, and transferred to a ball mill for ball milling at 600 rpm for 15 h to obtain a mixed solution B; (3) Mixing the mixed solution A and the mixed solution B, ultrasonically dispersing for 30 minutes to obtain a premix, adding 0.5 g of benzoyl peroxide and 0.08 g of N,N-dimethylacetamide and ultrasonically dispersing for 10 minutes to obtain a slurry containing nickel oxide.

[0042] Comparative Example 1 The difference from Example 1 is that the mass ratio of the organic monomer to the cross-linking agent in this comparative example is 1:1.

[0043] Comparative Example 2 The difference from Example 1 is that in this comparative example, the mass ratio of nickel oxide to sintering aid is 1:0.4.

[0044] Comparative Example 3 The difference from Example 1 is that the mass ratio of cadmium oxide to samarium oxide in this comparative example is 1:5.

[0045] Comparative Example 4 The difference from Example 1 is that no samarium oxide is added in this comparative example.

[0046] Comparative Example 5 The difference from Example 1 is that no cadmium oxide is added in this comparative example.

[0047] Comparative Example 6 The difference from Example 1 is that in this comparative example, an equal amount of zinc oxide is used instead of cadmium oxide.

[0048] Comparative Example 7 The difference from Example 1 is that in this comparative example, the mass ratio of polyvinyl pyrrolidone, diglycolamine and hydroxymethyl cellulose is 1:2:5.

[0049] Comparative Example 8 The difference from Example 1 is that no additive is used in this comparative example.

[0050] Comparative Example 9 The difference from Example 1 is that ultrasonic dispersion is not performed in step (2) of this comparative example.

[0051] Comparative Example 10 The difference from Example 1 is that the temperature of the second stage sintering in this comparative example is 1700°C.

[0052] Comparative Example 11 The difference from Example 1 is that in this comparative example, the mixed solution B is directly granulated using a spray dryer, passed through a 150-mesh sieve, and pressed into shape using a cold isostatic press at 200 MPa. The resulting green body is sintered at a high temperature, and the temperature sintering parameters are set the same as step S4 of Example 1.

[0053] The large-size nickel oxide planar targets prepared in Examples 1 to 4 and Comparative Examples 1 to 11 were subjected to relevant performance tests, and the test results are shown in Table 1.

[0054] Table 1 Test results

[0055] From the comparison between Comparative Example 1 and Example 1, it can be seen that excessive use of the cross-linking agent leads to the formation of a large number of cross-linking points, increased slurry viscosity, poor fluidity, and defects such as local uneven density, which affect the performance of the target material.

[0056] From the comparison between Comparative Example 2 and Example 1, it can be seen that the increase in the amount of sintering aid leads to excessive lattice distortion, decreased lattice stability, and increased defect density inside the crystal.

[0057] By comparing Comparative Examples 3, 4 and 5 with Example 1, it can be seen that the ratio of cadmium oxide to samarium oxide changes, and the performance of the planar target decreases, which proves that the ratio of cadmium oxide to samarium oxide in the present invention reaches the optimal ratio.

[0058] By comparing Comparative Example 6 with Example 1, it can be seen that zinc oxide can also make the relative density of the planar target reach more than 99%, but the improvement of the electrical properties of the planar target by zinc oxide is slightly worse than that of cadmium oxide; when nickel oxide is used as a sintering aid, the improvement of the carrier concentration and mobility by the energy band interaction between the two is greater than the interaction when zinc oxide is used as a sintering aid.

[0059] By comparing Comparative Examples 7 and 8 with Example 1, it can be seen that the addition of hydroxymethyl cellulose increases the viscosity of the system, reduces the dispersion performance of powders such as nickel oxide, and easily makes the target material locally uneven, affecting the performance of the film in the subsequent sputtering process; the presence of additives can significantly improve the dispersion stability of powders such as nickel oxide and improve the performance of the planar target.

[0060] From the comparison between Comparative Example 9 and Example 1, it can be seen that ultrasonic dispersion can promote the dispersion of nickel oxide and sintering aid powders to avoid agglomeration.

[0061] From the comparison between Comparative Example 10 and Example 1, it can be seen that a higher sintering temperature easily leads to abnormal growth of grains inside the planar target and reduced density.

[0062] By comparing Comparative Example 11 with Example 1, it can be seen that the densification rate of the ceramic after the initial use of gel injection molding and pre-sintering is faster, which can reduce the shrinkage of the green body during subsequent isostatic pressing and temperature sintering, reduce the internal stress caused by uneven shrinkage, and make the grain size more uniform; subsequent isostatic pressing can make the green body reach a higher density and uniformity in a shorter time; therefore, the present invention uses gel injection molding for pre-sintering for the first time, and uses cold isostatic pressing for segmented sintering to prepare the target material for the second time.

[0063] The large-size nickel oxide plane target prepared by the invention has lower resistivity and higher relative density.

[0064] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any equivalent changes or modifications made according to the essence of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for producing a large-size nickel oxide planar target, characterized in that: The steps include: S1: injecting a slurry containing nickel oxide into a mold and drying it to obtain a primary green body; S2: After the primary green body is debonded, it is pre-sintered in an oxygen-free atmosphere; S3: crushing the pre-sintered primary green body, sieving to obtain powder, adding a binder and mixing evenly, granulating, sieving, and cold isostatic pressing to obtain a secondary green body; S4: The secondary green body is heated and sintered to obtain a large-sized nickel oxide planar target.

2. The method for producing a large-size nickel oxide planar target according to claim 1, characterized in that: In step S1, the method for preparing the slurry containing nickel oxide comprises the following steps: (1) Mix the organic monomer, cross-linking agent and water evenly, and adjust the pH to 8-10 to obtain a mixed solution A; (2) uniformly mixing nickel oxide, sintering aid, additives and water to obtain a mixed solution B; (3) Mix the mixed solution A and the mixed solution B to obtain a premix, add an initiator and a catalyst and mix them to obtain a slurry containing nickel oxide.

3. The method for producing a large-size nickel oxide planar target according to claim 2, characterized in that: The mass ratio of the organic monomer to nickel oxide is (0.015-0.04):1, and the organic monomer is one of methacrylamide and ethyl methacrylate.

4. The method for producing a large-size nickel oxide planar target according to claim 2, characterized in that: In the step (2), the mass ratio of nickel oxide to sintering aid is 1:(0.01-0.03).

5. The method for producing a large-size nickel oxide planar target according to claim 2, characterized in that: In the step (2), the sintering aid is composed of cadmium oxide and samarium oxide in a mass ratio of (2-4):

1.

6. The method for producing a large-size nickel oxide planar target according to claim 2, characterized in that: In the step (2), the amount of the additive is 0.5%-1.5% of the mass of the nickel oxide.

7. The method for producing a large-size nickel oxide planar target according to claim 2, characterized in that: In the step (2), the additive is polyvinyl pyrrolidone, diglycolamine and hydroxymethyl cellulose in a mass ratio of (5-8) : 1 : (2-4).

8. The method for producing a large-size nickel oxide planar target according to claim 2, characterized in that: In the step (2), the uniform mixing includes ultrasonic dispersion and ball milling, which is specifically as follows: The ultrasonic dispersion time is 20-30min; The ball milling speed is 400-800 rpm, and the ball milling time is 10-15 h.

9. The method for producing a large-size nickel oxide planar target according to claim 1, characterized in that: In step S2, the specific steps of pre-sintering are as follows: sintering the primary green body at normal pressure at a temperature of 850-900°C, a heating rate of 3-5°C / min, a holding time of 3-5h, and cooling to room temperature with the furnace.

10. The method for producing a large-size nickel oxide planar target according to claim 1, characterized in that: In the step S4, the temperature rising sintering includes the first stage sintering and the second stage sintering, which are specifically as follows: during the first stage sintering process, neon gas is introduced, the sintering temperature is 500-800°C, the heating rate is 0.5-1.5°C / min, the insulation time is 3-8h, and the sintering pressure is 20-80Pa; during the second stage sintering process, oxygen is introduced, the sintering temperature is 1250-1350°C, the heating rate is 3-5°C / min, the sintering time is 8-20h, the sintering pressure is 200-500Pa, and the insulation time is 2-8h; the heating rate from the first stage sintering temperature to the second stage sintering temperature is 2°C / min.

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