Evaporation material and method for producing the same

Abstract

The application belongs to the technical field of semiconductor materials, and discloses a preparation method of an evaporation material, which comprises the following steps: mixing indium oxide powder and tungsten trioxide powder, primary sintering, adding water, pressing to obtain a blank, burying the blank by using a coating material, and secondary sintering, so that the evaporation material is obtained. The preparation method provided by the application is simple in process, low in energy consumption and production cost compared with the prior art, and is beneficial to popularization and marketization. The blank is buried by using the coating material before calcination, so that the color difference of IWO material in the sintering process caused by the loss of oxygen of tungsten trioxide is avoided. In addition, the application further provides the evaporation material prepared by the above preparation method.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor materials technology, and relates to the preparation of a vapor deposition material, specifically to a vapor deposition material and its preparation method. Background Technology

[0002] Among various thin film materials, transparent conductive films are widely used in solar cells, energy-saving building glass, various sensors, and flat panel displays. Indium oxide (ICO) is an n-type semiconductor material widely used in solar cells due to its near-metallic conductivity and high visible light transmittance. Transparent conductive oxide (TCO) films require high transmittance and high conductivity in the visible light spectrum. Indium oxide doped with tungsten oxide (IWO) exhibits both high transmittance and conductivity.

[0003] CN105374901A discloses a method for preparing IWO material for transparent electrodes in thin-film solar cells. The method involves mixing In₂O₃ powder and WO₃ powder, adding water, organic additives, and organic binders, ball milling, spray drying granulation, removing organic additives, and sintering to achieve densification, thereby obtaining the IWO ceramic semiconductor material. The prepared IWO ceramic semiconductor material exhibits good electrical conductivity, with a bulk resistivity of less than 7 × 10⁻³ Ω·cm.

[0004] However, the above-mentioned process for preparing IWO materials is cumbersome, and it is also necessary to keep the blank at 300-600℃ for 2-5 hours to remove organic additives, and then sinter it at 1300-1580℃ in an oxygen atmosphere furnace or an air furnace to make it dense. The preparation process is cumbersome, energy-intensive, and has high production costs, which is not conducive to promotion and marketization. Summary of the Invention

[0005] In view of the problems existing in the prior art, firstly, the present invention provides a method for preparing vapor deposition materials; secondly, the present invention provides a vapor deposition material.

[0006] In a first aspect, the present invention provides a method for preparing a vapor deposition material, comprising the following steps: Step 1: Mix indium oxide powder and tungsten trioxide powder to obtain mixed powder A; Step 2: Sinter the mixed powder A once, add water, and obtain the intermediate product; Step 3: Press the intermediate product to obtain the embryo; Step 4: Use a coating material to cover the preform and sinter it a second time to obtain the IWO vapor-deposited material.

[0007] Preferably, in step 1, the mass ratio of indium oxide powder to tungsten trioxide powder is 1:0.005~0.1.

[0008] Preferably, in step 1, after mixing indium oxide powder and tungsten trioxide powder, the mixture is sand-milled and spray-granulated to obtain mixed powder A.

[0009] Further preferred, the particle size of the mixed powder A is D50≤5μm.

[0010] Preferably, the secondary sintering temperature is lower than the primary sintering temperature.

[0011] Preferably, in step 2, the temperature of the first sintering is 1200~1350℃, and the sintering time is 3~5h.

[0012] Preferably, in step 2, after the powder A is sintered once, it is ball-milled and sieved to obtain coarse particles and fine particles; the coarse particles and fine particles are mixed at a mass ratio of 1:1 to 9, homogenized, and water is added to obtain an intermediate product.

[0013] Further optimization is achieved by having a D50 of 40-60 μm for coarse particles and a D50 of 5-10 μm for fine particles.

[0014] Further optimization yields an intermediate product with a solid-liquid ratio of 20-50:1 kg / L.

[0015] Preferably, in step 4, the coating material is one or more of indium oxide powder and IWO powder.

[0016] Further optimization suggests that the coating material can be recycled back to step 1 as a raw material for production.

[0017] Further optimization yields a coating thickness of 3-5 mm.

[0018] Secondly, the present invention provides a vapor deposition material prepared by the above-described preparation method.

[0019] Preferably, the vapor-deposited material has no color difference on its surface and inside, and both are yellow.

[0020] Compared with the prior art, one or more technical solutions provided by the present invention have the following significant advantages: (1) The preparation method provided by the present invention is simple in process, and compared with the prior art, it has low energy consumption and low production cost, which is conducive to promotion and marketization.

[0021] (2) Before calcining the green body, use a coating material to cover the green body to avoid the loss of oxygen of tungsten trioxide, which would cause color difference in IWO during sintering.

[0022] (3) By setting up two sintering stages, the powder is sintered first, and then the powder is pressed into a blank and sintered again, which can reduce the possibility of the blank cracking. Detailed Implementation

[0023] The present invention provides the following specific technical solutions.

[0024] In a first aspect, a method for preparing a vapor deposition material includes the following steps: Step 1: Mix indium oxide powder and tungsten trioxide powder to obtain mixed powder A; Step 2: Sinter the mixed powder A once, add water, and obtain the intermediate product; Step 3: Press the intermediate product to obtain the embryo; Step 4: Use a coating material to cover the preform and sinter it a second time to obtain the IWO vapor-deposited material.

[0025] In existing technologies, when preparing IWO materials using indium oxide powder and tungsten trioxide, tungsten trioxide may lose oxygen during calcination. In this oxygen-deprived state, tungsten trioxide is prone to developing blue and purple tungsten, causing discoloration of the IWO vapor-deposited material surface and affecting its performance. The inventors discovered that using a coating material to bury the preform during calcination can prevent oxygen loss from tungsten trioxide during sintering, ensuring the quality of the finished IWO vapor-deposited material.

[0026] Further research by the inventors revealed that during the sintering of the indium oxide and tungsten trioxide mixed powder, the powder particles undergo a reaction shrinkage. If the powder is pressed into a blank before sintering, it easily leads to cracking of the blank. The preparation method provided by this invention, by incorporating a two-stage sintering process—first sintering the powder, then pressing it into a blank, and finally sintering it again—reduces the likelihood of blank cracking. Preferably, in step 1, the mass ratio of indium oxide powder to tungsten trioxide powder is 1:0.005~0.1.

[0027] In practical applications, the mass ratio of indium oxide powder to tungsten trioxide powder can be selected according to actual needs. In specific embodiments of the present invention, the mass ratio of indium oxide powder to tungsten trioxide powder can be 1:0.005, 1:0.03, or 1:0.1.

[0028] Preferably, the temperature of the secondary sintering is lower than that of the primary sintering.

[0029] The inventors discovered through research that the lower temperature of the secondary sintering results in less bonding force between particles inside the preform, which can further prevent cracking caused by stress generated by heat during the evaporation coating process.

[0030] Preferably, in step 2, the temperature of the first sintering is 1200~1350℃, and the sintering time is 3~5h.

[0031] Preferably, in step 4, the temperature of the secondary sintering is 900~1100℃, and the time of the secondary sintering is 5~8h.

[0032] Preferably, in step 1, after mixing indium oxide powder and tungsten trioxide powder, the mixture is sand-milled and spray-granulated to obtain mixed powder A.

[0033] In practice, the amount of water added during sand milling and spray granulation can be selected according to the actual situation.

[0034] Preferably, in step 2, after the powder A is sintered once, it is ball-milled and sieved to obtain coarse particles and fine particles; the coarse particles and fine particles are mixed at a mass ratio of 1:1 to 9, water is added, and homogenization is carried out to obtain an intermediate product.

[0035] The inventors discovered that by mixing coarse and fine particles, with the fine particles filling the pores of the coarse particles, the density of the embryo can be controlled by adjusting the ratio of coarse to fine particles. In practical applications, the mass ratio of coarse to fine particles can be adjusted according to actual needs.

[0036] Further optimization is achieved by having a D50 of 40-60 μm for coarse particles and a D50 of 5-10 μm for fine particles.

[0037] Further optimization yields an intermediate product with a solid-liquid ratio of 20-50:1 kg / L.

[0038] In practice, the D50 of coarse particles, the D50 of fine particles, and the solid-liquid ratio of intermediate products can be adjusted according to actual conditions. In specific embodiments of the present invention, the D50 of coarse particles can be 40 μm, 50 μm, or 60 μm; the particle size of fine particles can be 5.12 μm, 6.25 μm, or 9.86 μm; and the solid-liquid ratio of intermediate products can be 20:1 Kg / L, 35:1 Kg / L, or 50:1 Kg / L.

[0039] Preferably, in step 4, the coating material is one or more of indium oxide powder and IWO powder.

[0040] The inventors discovered through research that using indium oxide powder and IWO powder as coating materials can avoid introducing other impurities and improve product quality.

[0041] Further optimization suggests that the coating material can be recycled back to step 1 as a raw material for production.

[0042] Further optimization yields a coating thickness of 3-5 mm.

[0043] In practical applications, the coating thickness can be selected according to actual needs. In specific embodiments of the present invention, the coating thickness can be 3mm, 4mm, or 5mm.

[0044] Secondly, a vapor deposition material is prepared by the above-mentioned preparation method.

[0045] Preferably, the vapor-deposited material has no color difference between its surface and interior, and the vapor-deposited material is yellow.

[0046] To make the technical problems to be solved, the technical solutions and the technical advantages of the present invention clearer, a detailed description will be given below with reference to specific examples. However, the scope of protection of the present invention is not limited to the following specific embodiments.

[0047] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0048] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0049] Example 1: A method for preparing a vapor deposition material includes the following steps: Step 1: Mix 30 kg of indium oxide and 0.9 kg of tungsten trioxide, add deionized water, sand mill, and spray granulate to obtain mixed powder A.

[0050] Step 2: Mixed powder A is sintered at 1275℃ for 4 hours. After ball milling, the mixed powder A is sieved to obtain fine particles (undersize) and coarse particles (oversize). The D50 of the fine particles is 6.25 μm and the D50 of the coarse particles is 50 μm. The fine and coarse particles are mixed at a mass ratio of 1.5:1, and water is added at a solid-liquid ratio of 35:1 kg / L. The mixture is homogenized for 0.5 hours to obtain an intermediate product.

[0051] Step 3: Pour the intermediate product into the mold and press it into a 30*30mm blank.

[0052] Step 4: Spread a 4mm thick layer of indium oxide powder at the bottom of the crucible, place the blank in the crucible, and continue adding indium oxide. Spread another 4mm thick layer of indium oxide powder on the surface of the blank, ensuring the indium oxide powder completely coats the blank. Sinter at 1000℃ for 6 hours. After sintering, recover the indium oxide to obtain a yellow IWO vapor-deposited material with a density of 4.0 g / cm³. 3 Upon cutting it open, both the inside and the surface are yellow, with consistent color throughout and no color difference.

[0053] Example 2: A method for preparing a vapor deposition material includes the following steps: Step 1: Mix 30 kg of indium oxide powder and 0.3 kg of tungsten trioxide powder, add deionized water, sand mill, and spray granulate to obtain mixed powder A.

[0054] Step 2: Sinter the mixed powder A at 1200℃ for 2 hours. After ball milling and sintering, sieve the mixed powder A to obtain fine particles (undersize) and coarse particles (oversize). The D50 of the fine particles is 40 μm and the D50 of the coarse particles is 5.12 μm. Mix the fine particles (undersize) and coarse particles (oversize) at a mass ratio of 1:1, add water at a solid-liquid ratio of 50:1 kg / L, and homogenize for 0.5 hours to obtain the intermediate product.

[0055] Step 3: Pour the intermediate product into the mold and press it into a 30*30mm blank.

[0056] Step 4: Spread a 3mm thick layer of indium oxide powder at the bottom of the crucible, place the blank in the crucible, continue adding indium oxide, and spread a 3mm thick layer of IWO powder on the surface of the blank, ensuring the indium oxide powder completely coats the blank. Sinter at 900℃ for 5 hours. After sintering, recover the indium oxide to obtain a yellow IWO vapor-deposited material with a density of 4.03 g / cm³. 3 When cut open and observed, both the inside and the surface are yellow, with a consistent color.

[0057] Example 3: A method for preparing a vapor deposition material includes the following steps: Step 1: Mix 30 kg of indium oxide powder and 3 kg of tungsten trioxide powder, add deionized water, sand mill, and spray granulate to obtain mixed powder A.

[0058] Step 2: Mixed powder A is sintered at 1350℃ for 4 hours. After ball milling and sintering, mixed powder A is sieved through a 200-mesh sieve to obtain fine particles (undersize) and coarse particles (oversize). The D50 of the coarse particles is 60μm, and the particle size of the fine particles is 9.86μm. The fine particles (undersize) and coarse particles (oversize) are mixed at a mass ratio of 9:1, and water is added at a solid-liquid ratio of 20:1 kg / L. The mixture is homogenized for 1 hour to obtain the intermediate product.

[0059] Step 3: Pour the intermediate product into the mold and press it into a 30*30mm blank.

[0060] Step 4: Spread a 5mm thick layer of IWO powder at the bottom of the crucible, place the blank in the crucible, add indium oxide, and spread a 5mm thick layer of IWO powder on the surface of the blank, ensuring the indium oxide powder completely coats the blank. Sinter at 1100℃ for 8 hours. After sintering, recover the indium oxide to obtain a yellow IWO vapor-deposited material with a density of 3.96 g / cm³. 3 When cut open and observed, both the inside and the surface are yellow, with a consistent color.

[0061] Comparative Example 1: The difference from Example 1 is that in step 5, indium oxide powder was not used to embed the preform; instead, the preform was directly sintered to obtain the IWO vapor-deposited material with a density of 4.05 g / cm³. 3 When cut open, the inside is yellow and the surface is blue.

[0062] As can be seen from Examples 1-3 and Comparative Example 1, calcination after coating the preform with coating material can prevent the surface of the IWO vapor-deposited material from being oxidized, thus making the color of the inside and the surface of the IWO vapor-deposited material consistent.

[0063] Comparative Example 2: A method for preparing a vapor deposition material includes the following steps: Step 1: Pour the mixed powder A obtained in Example 1 into a mold and press it into a 30*30mm blank.

[0064] Step 2: Place a 4mm thick layer of indium oxide powder at the bottom of the crucible, place the blank in the crucible, and continue adding indium oxide. Then, place another 4mm thick layer of indium oxide powder on the surface of the blank, ensuring the powder completely coats the blank. Sinter at 1000℃ for 4 hours. After sintering, remove the indium oxide to obtain the IWO vapor-deposited material with a density of 3.5 g / cm³. 3 Cracks appeared in the target material.

[0065] As can be seen from Examples 1-3 and Comparative Example 2, by setting a two-stage sintering process to produce vapor-deposited materials, cracking of vapor-deposited materials can be avoided, yield can be improved, and subsequent use can be avoided.

[0066] The above description is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a vapor deposition material, characterized in that, Includes the following steps: Step 1: After mixing indium oxide powder and tungsten trioxide powder, the mixture is sand-milled and spray-granulated to obtain mixed powder A; Step 2: Sinter the mixed powder A once, then ball mill and sieve it to obtain coarse and fine particles; mix the coarse and fine particles at a mass ratio of 1:1 to 9, homogenize, add water to obtain an intermediate product; the temperature of the first sintering is 1200 to 1350℃, and the time of the first sintering is 3 to 5 hours. The D50 of coarse particles is 40~60μm; the D50 of fine particles is 5~10μm. Step 3: Press the intermediate product to obtain the embryo; Step 4: Use a coating material to cover the preform and sinter it a second time to obtain the IWO vapor-deposited material; the temperature of the second sintering is 900~1100℃ and the time of the second sintering is 5~8h.

2. The method for preparing the vapor-deposited material according to claim 1, characterized in that, In step 1, the mass ratio of indium oxide powder to tungsten trioxide powder is 1:0.005~0.

1.

3. The method for preparing the vapor-deposited material according to claim 1, characterized in that, In step 2, the solid-liquid ratio of the intermediate product is 20~50:1Kg / L.

4. The method for preparing the vapor-deposited material according to claim 1, characterized in that, In step 4, the coating material is one or both of indium oxide powder and IWO powder.

5. The method for preparing the vapor-deposited material according to claim 1 or 4, characterized in that, The coating material can be recycled back to step 1 as a raw material for production.

6. The method for preparing the vapor-deposited material according to claim 1 or 4, characterized in that, The coating thickness is 3~5mm.

7. A vapor deposition material, characterized in that, The material is prepared by the method described in any one of claims 1 to 6; the surface and interior of the vapor-deposited material have no color difference and are both yellow.