Low-indium ceramic target material, method for preparing same, and use thereof
By adding zinc oxide, tin, and various metal oxides to an indium oxide matrix, a high-density, low-indium ceramic target material was prepared, which solved the problem of high cost of indium oxide-based targets, improved the mobility of TCO thin films, and achieved cost reduction and performance improvement.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ZHONGSHAN ZL ADVANCED MATERIALS TECHNOLOGY
- Filing Date
- 2025-05-27
- Publication Date
- 2026-05-26
AI Technical Summary
Existing indium oxide-based targets are expensive and scarce. Reducing the indium content leads to increased resistivity and low mobility of the target, resulting in reduced photoelectric performance. It is difficult to reduce costs while ensuring the performance of TCO thin films.
Low-indium ceramic targets are prepared by using indium oxide, zinc oxide, and tin oxide as matrix materials and adding metal oxides such as praseodymium oxide, hafnium oxide, terbium oxide, dysprosium oxide, and cerium oxide through ball milling, cold isostatic pressing, and sintering. This improves the density, reduces the sintering temperature, enhances the crystal structure stability and doping efficiency, and reduces grain boundary scattering.
The prepared low-indium ceramic target material has high density, significantly improved TCO film mobility, and reduced raw material costs, thus achieving a reduction in solar cell production costs while ensuring photoelectric performance.
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Figure BDA0005420914850000041 
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Abstract
Description
Technical Field
[0001] This invention relates to the field of photovoltaic target technology, and in particular to a low-indium ceramic target, its preparation method, and its application. Background Technology
[0002] Heterojunction, perovskite, and tandem solar cells have high theoretical efficiency and simple fabrication processes, making them a hot topic in current solar cell research and industrialization. Transparent conductive oxide thin films (TCO films) are key materials in these cells, and their photoelectric properties have a significant impact on the cell's conversion efficiency.
[0003] On the other hand, industrially, indium oxide-based targets are mainly used as raw materials, and magnetron sputtering is employed to prepare TCO thin films. However, indium, as a rare and dispersed metal, is expensive and scarce, resulting in high costs for indium oxide-based targets. This undoubtedly increases the manufacturing costs of heterojunctions, perovskites, and their tandem cells. Cost reduction and efficiency improvement are perpetual themes in the development of solar cells, thus requiring the development of a high-efficiency and low-cost target material.
[0004] Currently, the main indium oxide (ICO)-based photoelectric targets used in the photovoltaic field are 90 / 10, 97 / 3, and 99 / 1, with corresponding ICO mass fractions of 90 wt.%, 97 wt.%, and 99 wt.%, and corresponding ICO contents of 74.4 wt.%, 80.2 wt.%, and 81.9 wt.%, respectively. Reducing the ICO content in the target material is one of the main ways to reduce production costs while ensuring the TCO thin film maintains superior photoelectric performance. However, reducing the ICO content increases the resistivity and decreases the mobility of the target material, thus reducing its photoelectric performance.
[0005] Therefore, it is necessary to develop a low-indium ceramic target with high target density and good photoelectric properties. Summary of the Invention
[0006] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the first aspect of the present invention provides a low-indium ceramic target material with high density, and the TCO thin film prepared from the ceramic target material has high film mobility.
[0007] A second aspect of the present invention also provides a method for preparing a low-indium ceramic target.
[0008] A third aspect of the present invention also provides an application of a low-indium ceramic target.
[0009] According to a first aspect of the present invention, a low-indium ceramic target material is provided, comprising the following components calculated by mass percentage:
[0010] The content of indium oxide is 50.2%–60.8%; the content of zinc oxide is 16.8%–25.3%; the content of tin oxide is 18.0%–28.3%; the content of metal oxide is 0.10%–2.5%; and the sum of the contents of all components is 100%.
[0011] The metal oxide includes at least three of the following: praseodymium oxide, hafnium oxide, terbium oxide, dysprosium oxide, and cerium oxide.
[0012] According to a preferred embodiment of the present invention, the low-indium ceramic target material comprises the following components calculated by mass percentage:
[0013] The content of indium oxide is 50.2%–60.8%; the content of zinc oxide is 19.2%–25%; the content of tin oxide is 18.0%–22.8%; the content of metal oxide is 1.60%–2.0%; and the sum of the contents of all components is 100%.
[0014] The metal oxide includes at least three of the following: praseodymium oxide, hafnium oxide, terbium oxide, dysprosium oxide, and cerium oxide.
[0015] The low-indium ceramic target material according to embodiments of the present invention has at least the following beneficial effects:
[0016] This invention uses indium oxide, tin oxide, and zinc oxide as the main matrix materials; and adds at least three metal oxides selected from praseodymium oxide, hafnium oxide, terbium oxide, dysprosium oxide, and cerium oxide. First, it has a good sintering aid effect, increases the density of the target material, and reduces the sintering temperature. In addition, the cations in indium tin zinc oxide have multiple crystallographic positions. Co-doping with these oxides can significantly improve the doping efficiency. Each cation occupies a different lattice position, increasing the stability and symmetry of the crystal structure and reducing the scattering of lattice distortion and defects overall. On the other hand, the combination of these metal oxides reduces the nucleation energy of the indium tin zinc oxide crystal. After heat treatment, the TCO thin film has a larger grain size, effectively reducing grain boundary scattering and thus improving mobility.
[0017] According to a second aspect of the present invention, a method for preparing a low-indium ceramic target is provided, comprising the following steps:
[0018] S1. Indium oxide, zinc oxide, tin oxide, metal oxide and water are mixed and ball-milled to obtain a slurry;
[0019] S2. Mix and stir the slurry, binder and plasticizer, and then spray granulate to obtain powder;
[0020] S3. The powder is subjected to cold isostatic pressing to obtain a green body;
[0021] S4. The raw blank is sintered to obtain the final product.
[0022] According to a preferred embodiment of the present invention, step S4, the sintering step includes:
[0023] First, raise the temperature to 600-800℃ and hold for heat preservation I; then raise the temperature to 1380-1460℃ and hold for heat preservation II.
[0024] According to a preferred embodiment of the present invention, the heat preservation time I is 2 to 6 hours. For example, it includes a sub-range of 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, or any two of these values.
[0025] According to a preferred embodiment of the present invention, the heat preservation time II is 5 to 20 hours. For example, it includes a sub-range of 5 hours, 8 hours, 10 hours, 12 hours, 15 hours, 18 hours, 20 hours, or any two of these values.
[0026] According to a preferred embodiment of the present invention, oxygen is introduced during heat preservation II.
[0027] According to a preferred embodiment of the present invention, the oxygen flow rate is 5 L / min to 50 L / min.
[0028] According to a preferred embodiment of the present invention, step S4, the sintering step includes:
[0029] First, heat the temperature to 600-800℃ at a rate of 0.3-1.2℃ / min and hold for temperature I; then heat the temperature to 1380-1460℃ at a rate of 1-3℃ / min and hold for temperature II.
[0030] According to a preferred embodiment of the present invention, in step S3, the pressure of the cold isostatic pressing is 150MPa to 350MPa.
[0031] According to a preferred embodiment of the present invention, in step S3, the cold isostatic pressing time is 10 min to 60 min.
[0032] According to a preferred embodiment of the present invention, the adhesive comprises at least one of polyvinyl alcohol, polyvinyl butyral, or polyvinylpyrrolidone.
[0033] According to a preferred embodiment of the present invention, the plasticizer includes at least one of polyethylene glycol, methylcellulose, or citrate.
[0034] According to a preferred embodiment of the present invention, the amount of binder added is 0.6% to 2.3% based on the total mass of the slurry.
[0035] According to a preferred embodiment of the present invention, the amount of plasticizer added is 0.2% to 1.0% based on the total mass of the slurry.
[0036] A third aspect of the present invention provides the application of the aforementioned low-indium ceramic target in the preparation of TCO thin films.
[0037] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Detailed Implementation
[0038] The following are specific embodiments of the present invention, and the technical solutions of the present invention will be further described in conjunction with the embodiments, but the present invention is not limited to these embodiments.
[0039] Unless otherwise specified, the reagents, methods and equipment used in this invention are all conventional reagents, methods and equipment in this technical field.
[0040] The raw materials used in the embodiments of this invention are as follows:
[0041] Indium oxide, zinc oxide, tin oxide, praseodymium oxide, hafnium oxide, terbium oxide, dysprosium oxide, and cerium oxide are all commercially available and have a purity of 4N or higher.
[0042] Example 1
[0043] This example provides a low-indium ceramic target material, the composition of which is shown in Table 1, and its preparation method is as follows:
[0044] S1. Mix the various oxide powders according to the proportion, add 1.5 times the total weight of the mixed powders of deionized water, and use a sand mill to ball mill to obtain a mixed slurry. Use a sand mill to sand mill for 10 hours so that the median particle size D50 of the powder in the slurry is ≤0.30μm.
[0045] S2. Add 0.80wt% polyvinyl alcohol and 0.30wt% methylcellulose to the slurry after sand milling, mix well, and then spray granulate to obtain granulated powder.
[0046] S3. Using a rotating target mold, inject the granulated powder into the mold, seal it, and place it in the hydraulic press chamber. The molding pressure is 200MPa, the holding time is 30min, and after cold isostatic pressing, demold to obtain the rotating target blank.
[0047] S4. Place the green blank in a sintering furnace and heat it to 700℃ at a heating rate of 0.5℃ / min. Hold it at this temperature for 3 hours to remove organic additives. After holding, start purging with oxygen at a rate of 35L / min and heat it to 1380℃ at a heating rate of 1.5℃ / min. Hold it at this temperature for 10 hours. After holding, stop purging with oxygen. Then cool it to room temperature at a cooling rate of 2℃ / min to obtain a high-density low-indium ceramic target.
[0048] This embodiment further provides a method for flaw detection and coating of the prepared low-indium target material, the specific method of which is as follows:
[0049] TCO thin film deposition: On a cleaned glass substrate, a TCO thin film is deposited using sputtering deposition with a deposition power of 5kW and a film thickness of 100nm.
[0050] Examples 2-10
[0051] Examples 2-10 provide a series of low-indium ceramic targets, the component amounts of which are shown in Table 1. The preparation methods are the same as in Example 1, and the maximum sintering temperatures are shown in Table 2.
[0052] Comparative Examples 1-4
[0053] Comparative Examples 1-4 provide a series of low-indium ceramic targets, the component amounts of which are shown in Table 1, and their preparation methods are the same as in Example 1.
[0054] Table 1 Examples 1-10 and Comparative Examples 1-4
[0055]
[0056] Performance testing
[0057] Density: The density of the target material was tested using the Archimedes displacement method.
[0058] Mobility testing of TCO thin films: TCO thin films were deposited on cleaned glass substrates using sputtering deposition with a deposition power of 1.0-10.0 kW and a film thickness of 100±10 nm. The mobility of the thin films was tested using a Hall effect meter. The results are shown in Table 2.
[0059] Table 2
[0060]
[0061] As shown in Table 2, the ceramic targets of the embodiments of the present invention all have high density (≥99.0%), and the TCO thin films prepared by magnetron sputtering have a mobility of 32.6-40.6 cm⁻¹. 2 / V·s, significantly higher than 25.6cm in Comparative Example 1. 2 / V·s. On the other hand, as shown in Table 1, the indium content in the raw materials of Examples 1-10 was 41.5-50.3 wt%, which was 24.1-32.9 wt% less than that of Comparative Example 1. Indium tin zinc oxide (InSnZnO) x It has an extremely light carrier effective mass (m * The TCO film exhibits a longer carrier relaxation time, and the addition of at least three of praseodymium oxide, hafnium oxide, terbium oxide, dysprosium oxide, and cerium oxide can further improve mobility. This is because the cations in indium tin zinc oxide have multiple crystallographic positions, and co-doping with multiple oxides can significantly improve doping efficiency. Each cation occupies a different lattice position, increasing the stability and symmetry of the crystal structure and reducing lattice distortion and defect scattering overall. On the other hand, the combination of these oxides reduces the nucleation energy of the indium tin zinc oxide crystal. After heat treatment, the TCO film has a larger grain size, effectively reducing grain boundary scattering and thus improving mobility.
[0062] In contrast, the ceramic target material of Comparative Example 1 has a matrix of Sn-doped In2O3 and a second crystal phase (mainly In4Sn3O). 12 The TCO films containing impurity scattering centers (such as In2SnO5, etc.) have relatively low mobility.
[0063] The low-indium ceramic targets of Comparative Examples 2-4 had low density, not reaching 99%; and the TCO films prepared from the low-indium ceramic targets of Comparative Examples 2-4 had low mobility.
[0064] Therefore, combining Tables 1 and 2, it can be seen that this patent prepared high-density, low-indium-content target materials, and the TCO thin films prepared by magnetron sputtering using these target materials as raw materials have high carrier mobility (≥32.6 cm⁻¹). 2 / V·s), while ensuring that TCO has a high mobility, the cost of raw materials is reduced by replacing indium oxide with cheaper raw materials, thereby helping to reduce the cost of solar cells.
[0065] The present invention has been described in detail above with reference to the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.
Claims
1. A low-indium ceramic target, characterized in that, Includes the following components calculated as a percentage by mass: The content of indium oxide is 50.2%~60.8%; the content of zinc oxide is 19.2%~25%; the content of tin oxide is 18.0%~22.8%; the content of metal oxide is 1.60%~2.0%; and the sum of the contents of indium oxide, zinc oxide, tin oxide and metal oxide is 100%. The metal oxide is at least three of the following: praseodymium oxide, hafnium oxide, terbium oxide, dysprosium oxide, and cerium oxide.
2. The method for preparing the low-indium ceramic target according to claim 1, characterized in that, Includes the following steps: S1. Indium oxide, zinc oxide, tin oxide, metal oxide and water are mixed and ball-milled to obtain a slurry; S2. Mix and stir the slurry, binder and plasticizer, and then spray granulate to obtain powder; S3. The powder is subjected to cold isostatic pressing to obtain a green body; S4. The raw blank is sintered to obtain the final product.
3. The method for preparing the low-indium ceramic target according to claim 2, characterized in that, In step S4, the sintering step includes: First, raise the temperature to 600~800℃ for heat preservation I; then raise the temperature to 1380~1460℃ for heat preservation II.
4. The method for preparing the low-indium ceramic target according to claim 3, characterized in that, The heat preservation time is 2-6 hours.
5. The method for preparing the low-indium ceramic target according to claim 3, characterized in that, The heat preservation time II is 5~20h.
6. The method for preparing the low-indium ceramic target according to claim 3, characterized in that, Oxygen was introduced while performing Insulation II.
7. The method for preparing the low-indium ceramic target according to claim 3, characterized in that, In step S3, the pressure of the cold isostatic pressing is 150 MPa ~ 350 MPa.
8. The method for preparing the low-indium ceramic target according to claim 3, characterized in that, The adhesive includes at least one of polyvinyl alcohol, polyvinyl butyral, or polyvinylpyrrolidone.
9. The application of the low-indium ceramic target as described in claim 1 in the preparation of TCO thin films.