Preparation method of low-resistance high-transmittance low-indium target material

Abstract

The invention relates to the field of target material manufacturing, and provides a preparation method of a low-resistance, high-permeability and low-indium target material, nanoscale powder is adopted as a raw material, the diameter of the powder is 100-500 nm, the purity of the powder is larger than or equal to 99.99%, the density of the target material can be further improved, the sanding time is shortened, the efficiency is improved, and the cost is saved. And the ratio of the raw material powder is as follows: indium oxide: zinc oxide: tin oxide: cerium oxide = (1-20%): (10-30%): (60-80%): (1-2%), so that high transmittance and low resistance can be realized. The high-density target material can be obtained by firstly sanding powder, adding a dispersing agent, a binding agent and a defoaming agent in the sanding process, then granulating the powder, then carrying out cold press molding twice, and finally carrying out high-temperature and high-pressure sintering.

Description

Technical Field

[0001] The invention relates to the field of target material manufacturing, and in particular to a method for preparing a low-resistance, high-transmittance, low-indium target material. Background Art

[0002] In modern science and technology industries, such as electronic displays, thin-film solar cells and other fields, the performance requirements for target materials are getting higher and higher. Traditional target materials are often difficult to meet the evolving technological needs in terms of performance such as resistance and transmittance, and indium is a rare and expensive metal, and reducing its content in target materials has important economic and resource significance. In order to reduce costs, heterojunction batteries prepared by indium-based + low-indium-based stacking are used, and their conversion efficiency is already on par with all-indium-based batteries. At present, the existing target material preparation methods have problems such as complex processes, high costs, and unsatisfactory performance. At the same time, the heterojunction battery industry has relatively high requirements for resistance and transmittance. Therefore, it is of great practical significance to develop a method for preparing a target material with low resistance, high transmittance, and low indium. Summary of the invention

[0003] In view of this, the purpose of the present invention is to provide a method for preparing a low-resistance, high-transmittance, low-indium target material to solve the problems of high resistance, low transmittance and high indium content in existing target materials.

[0004] Based on the above purpose, the present invention provides a method for preparing a low-resistance, high-transmittance, low-indium target material, comprising the following steps:

[0005] Step 1: Slurry sanding:

[0006] The mixing ratio of powder is "indium oxide: zinc oxide: tin oxide: cerium oxide = 1-20%: 10-30%: 60-80%: 1-2%", and the amount of deionized water added is 30-50% of the total mass of the raw materials. After the powder mixing is completed, the powder slurry is sanded with a sand mill. During the grinding process, dispersant BLJ-3359, binder BD25, BD20, and defoamer MOK-6026 are added to finally obtain a slurry particle size of D10≤0.1μm, D50≤0.2μm, and D90≤0.9μm;

[0007] Step 2: Powder granulation:

[0008] After the sand-milled slurry reaches the required particle size, it is granulated by a high-temperature spray granulator;

[0009] Step 3: Cold Pressing:

[0010] Put the granulated powder into a 4-inch flat target mold, first use a hydraulic press to perform a pressure molding, use a vacuum machine to evacuate the flat target in a PE film bag, and then put it into cold isostatic pressing for secondary pressure molding;

[0011] Step 4: Target sintering:

[0012] The formed target material blank is placed in a sintering furnace for sintering. First, the temperature is increased to 650°C at a heating rate of 0.5-2°C / min for dehydration and degreasing, and then the temperature is increased from 650 to 900°C at a heating rate of 3-6°C / min, and then the temperature is increased from 900°C to 1500°C at 4-8°C / min and kept at this temperature for 10-20h. Finally, a low-resistance, high-transmittance, low-indium target material is obtained.

[0013] Preferably, in the step 1, indium oxide, zinc oxide, tin oxide and cerium oxide are selected from nano-powders with a particle size of 100nm to 500nm and a purity of ≥99.99%.

[0014] Preferably, in the step 1, the added amount of the dispersant BLJ-3359 is 0.1% to 0.6% wt, the added amount of the binders BD25 and BD20 is 1% to 5% wt, and the added amount of the defoamer MOK-6026 is 0.05 to 0.1% wt.

[0015] Preferably, in step 1, the sanding speed of the sand mill is 2000-3000 r / min, the number of grinding times is 3-5 times, and the grinding time is 5-10 hours.

[0016] Preferably, in step 2, the high-temperature spray granulator has an air inlet temperature of 190-240°C, an air outlet temperature of 90-130°C, and a spray granulation speed of 7000-9000 r / min.

[0017] Preferably, the molding pressure in step three is 100-200 MPa, and the molding time is 5-10 minutes.

[0018] Preferably, in step three, the secondary molding pressure is 180-210 MPa, and the molding time is 40-60 minutes.

[0019] Preferably, in step 4, the sintering pressure is 5-25 MPa; and the sintering atmosphere is a mixed gas of oxygen and nitrogen.

[0020] Preferably, in step 4, air is passed during the early stage of sintering from room temperature to 900°C, nitrogen and oxygen mixed gas is passed during the stage of 900 to 1500°C, i.e. the highest temperature insulation stage, and no air is passed in the later stage.

[0021] Beneficial effects of the present invention: The present invention uses nano-grade powder as raw material, the powder diameter is 100nm to 500nm, and the purity is ≥99.99%, which can further improve the density of the target material, reduce the sanding time, improve the efficiency, and save costs. And the raw material powder ratio is indium oxide: zinc oxide: tin oxide: cerium oxide = 1-20%: 10-30%: 60-80%: 1-2%, so that high transmittance and low resistance can be achieved. The powder is first sand-milled, dispersants, binders and defoamers are added during the sand-milling process, the powder is granulated, and then cold-pressed twice. Finally, high-temperature and high-pressure sintering is performed. The sintering temperature is increased to 650°C at a heating rate of 0.5-2°C / min for dehydration and degreasing; the heating rate is continued from 650 to 900°C at a heating rate of 3-6°C / min, and then the temperature is increased from 900°C to 1500°C at 4-8°C / min for 10-20h, and the target material is obtained by combining the early air atmosphere sintering and the later nitrogen-oxygen mixed atmosphere sintering. DETAILED DESCRIPTION

[0022] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0023] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0024] A method for preparing a low-resistance, high-transmittance, low-indium target material comprises the following steps:

[0025] S1, Slurry sanding:

[0026] The mixed powder ratio is "indium oxide: zinc oxide: tin oxide: cerium oxide = 1-20%: 10-30%: 60-80%: 1-2%", the amount of deionized water added is 30-50% of the total mass of the raw materials, indium oxide, zinc oxide, tin oxide, cerium oxide are selected from nano-grade powders, the powder particle size is 100nm ~ 500nm, the purity is ≥ 99.99%;

[0027] After the powder mixing is completed, the powder slurry is sanded with a sand mill, the sand mill speed is 2000-3000r / min, the grinding number is 3-5 times, and the grinding time is 5-10 hours; during the grinding process, dispersant BLJ-3359 0.1%~0.6%wt, binder BD25, BD20 1%~5%wt, defoamer MOK-6026 0.05~0.1%wt are added. Finally, the slurry particle size D10≤0.1μm, D50≤0.2μm, D90≤0.9μm is obtained;

[0028] S2, powder granulation:

[0029] After the sand-milled slurry reaches the particle size requirement, it is granulated by a high-temperature spray granulator. The inlet temperature of the high-temperature spray granulator is 190-240°C, the outlet temperature is 90-130°C, and the spray granulation speed is 7000-9000r / min.

[0030] Step 3: Cold Pressing:

[0031] Put the granulated powder into a 4-inch flat target mold, and first use a hydraulic press to perform a pressure molding, the molding pressure is 100-200MPa, and the molding time is 5-10 minutes; use a vacuum machine to evacuate the flat target in a PE film bag, and then put it into cold isostatic pressing for secondary pressure molding, the molding pressure is 180-210MPa, and the molding time is 40-60 minutes;

[0032] Step 4: Target sintering:

[0033] Place the formed target body into the sintering furnace, and sinter at a pressure of 5-25MPa.

[0034] First, the temperature is raised to 650°C at a heating rate of 0.5-2°C / min for dehydration and degreasing, and then the temperature is raised from 650-900°C at a heating rate of 3-6°C / min, and then the temperature is raised from 900°C to 1500°C at 4-8°C / min and kept warm for 10-20h; air is passed from room temperature to 900°C in the early stage of sintering, nitrogen and oxygen mixed gas is passed from 900-1500°C, which is the highest temperature insulation stage, and no air is passed in the later stage. Finally, a low-resistance, high-transmittance, low-indium target is obtained.

[0035] The process methods of Examples 1-4 are as above. The proportions of indium oxide, zinc oxide, oxide, and cerium oxide in Examples 1-4 are shown in the table below. The relative density, resistivity, and transmittance of the target materials finally obtained in Examples 1-4 are also shown in the table below. It can be seen that Example 3 has the highest relative density, the lowest resistivity, and the highest transmittance.

[0036]

[0037] It should be understood by those skilled in the art that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the present invention is limited to these examples; under the concept of the present invention, the technical features in the above embodiments or different embodiments may also be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity. Any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A method for preparing a low-resistance, high-transmittance, low-indium target material, characterized in that: The following steps are included: Step 1: Slurry sanding: The mixing ratio of powder is "indium oxide: zinc oxide: tin oxide: cerium oxide = 1-20%: 10-30%: 60-80%: 1-2%", and the amount of deionized water added is 30-50% of the total mass of the raw materials. After the powder mixing is completed, the powder slurry is sanded with a sand mill. During the grinding process, dispersant BLJ-3359, binder BD25, BD20, and defoamer MOK-6026 are added to finally obtain a slurry particle size of D10≤0.1μm, D50≤0.2μm, and D90≤0.9μm; Step 2: Powder granulation: After the sand-milled slurry reaches the required particle size, it is granulated by a high-temperature spray granulator; Step 3: Cold Pressing: Put the granulated powder into a 4-inch flat target mold, first use a hydraulic press to perform a pressure molding, use a vacuum machine to evacuate the flat target in a PE film bag, and then put it into cold isostatic pressing for secondary pressure molding; Step 4: Target sintering: The formed target material blank is placed in a sintering furnace for sintering. First, the temperature is increased to 650°C at a heating rate of 0.5-2°C / min for dehydration and degreasing, and then the temperature is increased from 650 to 900°C at a heating rate of 3-6°C / min, and then the temperature is increased from 900°C to 1500°C at 4-8°C / min and kept at this temperature for 10-20h. Finally, a low-resistance, high-transmittance, low-indium target material is obtained.

2. The method for preparing a low-resistance, high-transmittance, low-indium target material according to claim 1, characterized in that: In the step 1, indium oxide, zinc oxide, tin oxide and cerium oxide are selected from nanometer-grade powders with a particle size of 100nm to 500nm and a purity of ≥99.99%.

3. The method for preparing a low-resistance, high-transmittance, low-indium target material according to claim 2, characterized in that: In the step 1, the added amount of the dispersant BLJ-3359 is 0.1% to 0.6% wt, the added amount of the binders BD25 and BD20 is 1% to 5% wt, and the added amount of the defoamer MOK-6026 is 0.05 to 0.1% wt.

4. The method for preparing a low-resistance, high-transmittance, low-indium target material according to claim 3, characterized in that: In the step 1, the sand mill has a sand grinding speed of 2000-3000 r / min, the number of grinding times is 3-5 times, and the grinding time is 5-10 hours.

5. The method for preparing a low-resistance, high-transmittance, low-indium target material according to claim 1, characterized in that: In step 2, the air inlet temperature of the high-temperature spray granulator is 190-240°C, the air outlet temperature is 90-130°C, and the spray granulation speed is 7000-9000r / min.

6. The method for preparing a low-resistance, high-transmittance, low-indium target material according to claim 1, characterized in that: The first molding pressure in step three is 100-200 MPa, and the molding time is 5-10 minutes.

7. A method for preparing a low-resistance, high-transmittance, low-indium target material according to claim 6, characterized in that: The secondary molding pressure in step three is 180-210 MPa, and the molding time is 40-60 minutes.

8. The method for preparing a low-resistance, high-transmittance, low-indium target material according to claim 1, characterized in that: The sintering pressure in step 4 is 5-25 MPa; the sintering atmosphere is a mixed gas of oxygen and nitrogen.

9. The method for preparing a low-resistance, high-transmittance, low-indium target material according to claim 8, characterized in that: In the step 4, air is passed during the early stage of sintering from room temperature to 900° C., nitrogen and oxygen mixed gas is passed during the stage of 900 to 1500° C., i.e. the highest temperature insulation stage, and no air is passed in the later stage.

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