A tungsten-doped indium oxide target material and its preparation method and application

Abstract

The present invention discloses a tungsten-doped indium oxide target material, its preparation method, and application. Ammonia gas is introduced into an indium metal salt solution to cause a gas-liquid precipitation reaction to produce an indium hydroxide precursor slurry. Solid-liquid separation is then performed to produce indium hydroxide powder. The indium hydroxide powder is calcined to produce indium oxide powder. The indium hydroxide powder, indium oxide powder, and tungsten oxide powder are wet-ball milled to produce a ball mill material. The ball mill material is granulated to produce a granulated powder. The granulated powder is pressed into a green body. The green body is sintered in an oxygen atmosphere to produce an IWO target material with a relative density of 60-64%. The preparation method of the present invention eliminates the need for dispersants and binders and a degreasing step, simplifying the preparation process while facilitating quality control of the target material product. The resulting IWO target material exhibits a uniform porous structure, is resistant to cracking, and exhibits excellent coating properties. The preparation process of the present invention is simple, low-cost, low-carbon, environmentally friendly, and has controllable product performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of solar photovoltaic cell material preparation, and relates to a tungsten-doped indium oxide target material, a preparation method thereof, and an application thereof. Background Art

[0002] To achieve the 1.5°C climate goal, renewable energy must grow faster than energy demand. New data released by the International Renewable Energy Agency (IRENA) shows that despite global uncertainty, renewable energy continues to grow and gain momentum. By the end of 2021, global installed renewable energy capacity reached 3,064 GW, with solar power generation exceeding wind power capacity for the first time. As the mainstream development of third-generation solar cells, the photovoltaic industry's massive market will inevitably drive the development of heterojunction (HIT) cells, enabling them to secure greater policy and capital support.

[0003] As an electrode material, indium tin oxide (ITO) thin film is the most critical component of the HIT cell structure. ITO thin film's free carrier absorption problem in the near-infrared band restricts the spectral response of HIT cells in the long-wave region. Indium tungsten oxide (IWO) thin film has higher carrier mobility and near-infrared transmittance than ITO thin film, effectively solving these problems and becoming an ideal alternative to ITO thin film. Therefore, IWO, which can improve the efficiency of HJT cells, has naturally attracted significant attention from the industry and researchers.

[0004] At present, IWO targets for HIT batteries are mainly imported. "Cost reduction" and "efficiency improvement" are the eternal pursuits of the photovoltaic industry. Therefore, the localization of IWO targets has become a barrier facing the domestic HIT battery industry. 3 Taking IWO targets as an example, the price of domestic targets is about 60% of that of imported targets. Therefore, the localization of IWO targets is expected to reduce the target cost of HIT batteries by more than 40%.

[0005] IWO targets have a porous microstructure, and their preparation process primarily involves powder preparation, ball milling, and debinding and sintering. Powder preparation and ball milling are the core components of IWO target production technology. Conventional powder preparation uses ammonia as a precipitant, producing oxide powders through a liquid-liquid reaction between ammonia and a metal salt solution. While this technique is suitable for large-scale, rapid production of nanopowders, severe powder agglomeration is an inherent drawback. Furthermore, severe agglomeration significantly impacts the subsequent ball milling dispersion process, reducing milling efficiency and slurry quality. Conventional ball milling processes require the addition of organic substances such as dispersants and forming agents. These organic substances degrade and volatilize during the subsequent debinding and sintering process, significantly polluting the IWO target production environment. Furthermore, due to the porous structure of IWO targets, they absorb some of the emitted organic substances, contaminating the IWO film production process and impacting its quality.

[0006] Therefore, how to prepare nanopowders with good dispersibility and develop molding technology with little or no organic additives are technical problems that need to be solved urgently in the preparation of high-quality IWO targets. Summary of the Invention

[0007] In view of the shortcomings of the prior art, the first object of the present invention is to provide a method for preparing a tungsten-doped indium oxide target. The raw oxide powder prepared by the preparation method provided by the present invention has good dispersibility, no additives need to be added during the molding process, the preparation process is simple, controllable, pollution-free, and suitable for industrial production.

[0008] The second object of the present invention is to provide a tungsten-doped indium oxide target prepared by the above preparation method, wherein the tungsten-doped indium oxide target has uniform particle size, narrow distribution, uniform porous structure, is not easy to crack and has good coating properties.

[0009] The third object of the present invention is to provide an application of the tungsten-doped indium oxide target prepared by the above preparation method, and to use the tungsten-doped indium oxide target as a raw material for preparing IWO thin films in heterojunction (HIT) batteries.

[0010] In order to achieve the above object, the present invention adopts the following technical solutions:

[0011] The invention discloses a preparation method of a tungsten-doped indium oxide target material, comprising the following steps: introducing ammonia into an indium metal salt solution to carry out a gas-liquid precipitation reaction to obtain an indium hydroxide precursor slurry, performing solid-liquid separation to obtain indium hydroxide powder, calcining the indium hydroxide powder to obtain indium oxide powder, wet-ball-milling the indium hydroxide powder, indium oxide powder and tungsten oxide powder to obtain a ball milling material, granulating the ball milling material to obtain a granulated powder, pressing the granulated powder to obtain a green compact, and sintering the green compact in an oxygen atmosphere to obtain the tungsten-doped indium oxide target material.

[0012] The preparation method of the present invention adopts a gas-liquid precipitation reaction between ammonia and a metal salt solution, utilizes the boiling effect of the gas in the metal salt solution to obtain an indium hydroxide precursor, and calcines to prepare highly dispersible nano indium oxide powder. Then, utilizing the high viscosity of the indium hydroxide slurry, wet ball milling is performed using indium hydroxide powder, indium oxide powder and tungsten oxide powder as raw materials and water as a ball milling medium without any organic additives. Then, spray granulation is performed to obtain granulated powder. Finally, a green body is obtained through a near-net-shape forming technology, and the green body is placed in a flowing pure oxygen atmosphere for sintering to obtain an IWO target.

[0013] In a preferred embodiment, the indium metal salt solution is selected from at least one of an indium chloride solution, an indium nitrate solution, and an indium sulfate solution.

[0014] In a preferred embodiment, in the indium metal salt solution, In 3+ The concentration of indium is 0.5~2.0mol / L. 3+ When the concentration of is controlled within this range, the resulting indium hydroxide precursor has the best crystal form and the best particle size distribution.

[0015] In a preferred embodiment, the flow rate of ammonia gas introduced into the indium metal salt solution is 2 to 10 L / min. The inventors have discovered that controlling the flow rate of ammonia gas into the indium metal salt solution within this range ultimately yields a uniformly sized indium hydroxide precursor. However, if the ammonia gas flow rate is too high, the reaction may be incomplete, the instantaneous heat may be too high, and the temperature field in the solution may vary greatly, all of which may affect the particle size and crystal form of the indium hydroxide precursor and hinder the preparation of a uniformly sized powder. If the ammonia gas flow rate is too low, the reaction continuity may be poor, the powder from the early reaction may grow abnormally, and the high temperature in the reactor may cause ammonia to volatilize, all of which are also detrimental to the preparation of the indium hydroxide precursor.

[0016] In a preferred embodiment, the initial pH value of the indium metal salt solution is controlled to be ≤0.5, ammonia gas is introduced into the indium metal salt solution at 70-80°C for gas-liquid precipitation reaction until the pH value reaches 8-9, the introduction of ammonia gas is stopped, and the temperature is maintained for 60-240 minutes to obtain an indium hydroxide precursor slurry.

[0017] In the present invention, the initial pH value of the gas-liquid precipitation reaction is first controlled to be below 0.5. The inventors found that although the initial pH value of the metal salt solution is 3+ There is no direct relationship between the concentration, but controlling the initial pH value below 0.5 can obtain higher In 3+ concentration, and in 3+ Under conditions where the concentration is essentially the same, the starting point of the precipitation reaction is controlled; when precipitation begins, the precipitant preferentially reacts with the acid to generate heat, thereby obtaining a better particle size and crystal form of the indium hydroxide precursor. In addition, the inventors have discovered that when the introduction of ammonia is stopped and the temperature is maintained for 60 to 240 minutes, the indium hydroxide precursor can be given time to continue growing, thereby obtaining a powder with a consistent crystal form and facilitating the acquisition of a powder with a good particle size distribution.

[0018] In the actual operation process of the present invention, the gas-liquid precipitation reaction between ammonia gas and metal salt solution is carried out in a stainless steel reactor with a tetrafluoroethylene lining on the inner wall. The reaction bottom liquid temperature is 75±5°C. The metal salt solution is first added, and then ammonia gas is introduced into the metal salt solution at a flow rate of 2 to 10 L / min. The pH value at the reaction termination point is controlled at 8.5±0.5. After the reaction is completed, the mixture is stirred for 60 to 240 minutes under heat preservation to obtain an indium hydroxide precursor slurry.

[0019] In actual operation, the indium hydroxide precursor slurry is subjected to membrane separation washing and spray drying to obtain indium hydroxide powder.

[0020] In a preferred embodiment, the particle size D of the indium hydroxide powder is 50 2~10μm.

[0021] In a preferred embodiment, the calcination temperature is 600-1100° C., and the calcination time is 0.5-6 hours.

[0022] In a preferred embodiment, the BET of the indium oxide powder is 4 to 12 m 2 / g, particle size is 70~210nm.

[0023] The nano-indium oxide powder prepared by the invention has uniform particle size and excellent dispersibility.

[0024] In a preferred embodiment, the mass ratio of the indium hydroxide powder, indium oxide powder, and tungsten oxide powder is 5-20:79-85:1-10.

[0025] The inventors found that the slurry containing indium hydroxide powder has high viscosity. Therefore, the present invention uses indium hydroxide powder to replace the organic binder. At the same time, the indium hydroxide powder will dehydrate during the sintering process. Water is gaseous at high temperatures, which hinders the sintering densification process, thereby obtaining a porous IWO target. Of course, to obtain an IWO target with excellent performance, the mass ratio of indium hydroxide powder, indium oxide powder, and tungsten oxide powder needs to be controlled within the scope of the present invention. If too much indium hydroxide powder is added, the porosity of the IWO target is too high, the dehydration reaction is violent during the sintering process, and the target is prone to cracking; if too little indium hydroxide powder is added, it will not have a bonding effect, the dehydration reaction has a weak anti-densification effect on the sintering, and it is difficult to obtain the required porous IWO target. The addition of tungsten oxide powder is intended to make W 6+ Alternative In 3+ , generating excess free electrons in the target or film, and obtaining a high carrier concentration. 6+ Alternative In 3+ There is a limit to how much tungsten oxide powder can be added. Adding too much or too little tungsten oxide powder will deteriorate the conductivity of the IWO film and reduce the carrier concentration in the film. Furthermore, adding too much tungsten oxide powder will have an anti-densification effect, reducing the density of the IWO film.

[0026] In a preferred embodiment, the ball milling medium is water, and during the wet ball milling, the ratio of the mass of the added ball milling medium to the total mass of the indium hydroxide powder, indium oxide powder and tungsten oxide powder is 30-60:40-70.

[0027] During the actual operation, the water added is pure water or deionized water.

[0028] The amount of ball milling media is controlled within the above range to obtain the solid content of the ball mill. At this time, spherical powder with uniform particle size is obtained through granulation. If too much water is added, the solid content of the slurry will be too low, the slurry viscosity will be too low, the granulated powder particles will be non-spherical and the particle size will be too fine, and the production energy consumption will be too high. If the amount of water is too little, the solid content of the slurry will be too high, the slurry viscosity will be too high, the fluidity will be poor, granulation will not be possible, and the powder will not be dispersed, resulting in serious agglomeration.

[0029] In a preferred embodiment, the rotation speed of the wet ball milling is 30 to 100 r / min, and the wet ball milling time is 12 to 48 hours.

[0030] In a preferred embodiment, the particle size D of the granulated powder is 50 The particle size D of the granulated powder is 40 to 60 μm. 50Controlling within this range results in the ultimate tungsten-doped indium oxide target material with optimal performance. Furthermore, the granulated powder of the present invention exhibits a normal particle size distribution, with particles varying in size, resulting in excellent filling efficiency and the ability to produce green compacts with the highest bulk density. However, if the particle size of the granulated powder is too large, numerous small pores will form during the molding process, reducing the density of the green compact. If the particle size of the granulated powder is too small, the gap between the male and female molds of the mold will create a gap, and the powder will be too fine and prone to leakage. This will also hinder degassing during the molding process, and the molded green compact will be prone to delamination and cracking.

[0031] In a preferred embodiment, the pressing pressure is 20 to 30 MPa, and the holding time is 10 to 30 seconds.

[0032] In the actual operation process, the granulated powder obtained after granulation is placed in a steel mold or a cemented carbide mold for compression molding.

[0033] In a preferred embodiment, the sintering process is as follows: first, the temperature is raised to 600-900°C at a heating rate of 10-200°C / h for the first sintering stage, the holding time during the first sintering stage is controlled to be 30-100min, and the flow rate of oxygen introduced is 5-20L / min; then, the temperature is raised to 1100-1350°C at a heating rate of 60-200°C / h for the second sintering stage, the holding time during the second sintering stage is controlled to be 30-120min, and the flow rate of oxygen introduced is 10-30L / min; then, the temperature is raised to 1400-1500°C at a heating rate of 200-300°C / h for the third sintering stage, the holding time during the third sintering stage is controlled to be 240-480min, and the oxygen flow rate is 20-50L / min.

[0034] In the present invention, a tungsten-doped indium oxide target is obtained through three-step sintering. In the first step, a low temperature and a low heating rate are used to dehydrate the indium hydroxide to form a porous body without cracking the green body. In the second step, the heating rate, the sintering temperature and the O2 flow rate are increased to form a sintering neck in the green body, thereby improving the green body strength and density. In the third step, the temperature is rapidly increased and the sintering temperature is increased to further stabilize the density and allow the grains to grow. The most important thing is to allow the tungsten oxide to dissolve into the indium oxide lattice at high temperature to form a single phase.

[0035] In actual operation, the green body is placed in a common sintering furnace for sintering, and after the highest temperature is maintained, the temperature is naturally cooled down with the furnace.

[0036] The present invention also provides a tungsten-doped indium oxide target prepared by the above preparation method.

[0037] In the tungsten-doped indium oxide target, the mass fraction of tungsten oxide is 1 to 10 wt.%.

[0038] The tungsten-doped indium oxide target has an indium oxide single-phase structure, wherein tungsten is completely dissolved in the indium oxide lattice, the grain size is 5 to 20 μm, and the relative density is 60 to 64% (theoretical density 7.18 g / cm 3 ), purity ≥99.9%.

[0039] In this invention, the specific relative density range is achieved by coordinating the addition of indium hydroxide and the sintering process. The IWO thin film used in HIT cells is produced using evaporation, unlike the magnetron sputtering method used for ITO thin films. Given the characteristics of evaporation and industrial production practices, a target density of 60% to 64% is optimal.

[0040] The present invention also provides an application of a tungsten-doped indium oxide target prepared by the above preparation method, wherein the tungsten-doped indium oxide target is used as a raw material for preparing an IWO thin film in a heterojunction (HIT) battery.

[0041] Compared with the prior art, the advantages of the present invention are:

[0042] (1) A gas-liquid precipitation reaction between ammonia and a metal salt solution is used to prepare highly dispersed nanopowders by utilizing the boiling effect of the gas in the metal salt solution.

[0043] (2) Taking advantage of the high viscosity of indium hydroxide slurry, indium hydroxide powder, indium oxide powder and tungsten oxide powder are weighed according to the mass ratio, and then ball milling + spray granulation is performed to obtain granulated powder. Without any organic additives, the green blank is directly formed and then placed in an oxygen atmosphere for high-temperature sintering. The decomposition reaction of indium hydroxide is used to obtain an IWO target with a porous structure with uniform pore distribution.

[0044] Overall, the IWO particle preparation method of the present invention innovatively uses ammonia gas instead of aqueous ammonia as a precipitant, utilizing a gas-liquid precipitation reaction to facilitate the production of highly dispersible nanopowders. Furthermore, no dispersant or binder is added during the ball milling process, eliminating the need for a degreasing step. This simplifies the preparation process while also facilitating quality control and environmental protection for the target product. This method represents a first for IWO target preparation in China and is suitable for industrial production. Furthermore, the IWO target prepared by this method meets the technical requirements of reactive ion plating, exhibiting a uniform porous structure, resistance to cracking, and excellent coating properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0046] Figure 1 This is a flow chart of the preparation process of the IWO target material in the present invention.

[0047] Figure 2 This is a morphology diagram of indium hydroxide powder prepared by ammonia in Example 1 of the present invention.

[0048] Figure 3 This is a comparison of the morphologies of indium oxide powders prepared in Example 1 and Comparative Example 1 of the present invention; Figure 3 (a) The morphology of indium oxide powder prepared using ammonia in Example 1, Figure 3 (b) is the morphology of indium oxide powder prepared using ammonia water in comparative example 1.

[0049] Figure 4 This is a SEM image of the fracture surface of the IWO target prepared in Example 1 of the present invention.

[0050] Figure 5 This is a SEM image of the fracture surface of the IWO target prepared in Comparative Example 2 of the present invention. DETAILED DESCRIPTION

[0051] To facilitate understanding of the present invention, the present invention will be described in more comprehensive and detailed form below in conjunction with the accompanying drawings and preferred embodiments. However, the scope of protection of the present invention is not limited to the following specific embodiments.

[0052] Unless otherwise defined, all technical terms used hereinafter have the same meanings as those generally understood by those skilled in the art. The technical terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0053] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0054] In the present invention, the powder particle size distribution is detected by a Mastersizer 3000 particle size analyzer, the specific surface area of ​​the powder is measured by BET using a nitrogen adsorption method, the microstructure and grain size of the IWO target are detected by a scanning electron microscope, the phase structure is detected by an X-ray diffractometer, the size is measured by a micrometer, and the density of the target is determined by a size method.

[0055] Example 1:

[0056] The reaction vessel used is a stainless steel reactor with a PTFE-lined inner wall and a capacity of 500L. 3+The concentration is 1 mol / L, the initial pH value is controlled below 0.5, and the initial temperature is 75°C; ammonia is introduced for precipitation reaction, and the ammonia flow rate is 10 L / min; the pH is terminated at 8.5 after the reaction; after the precipitation reaction is completed, the mixture is kept warm and stirred for 120 minutes to obtain In(OH)3 precursor slurry, and the In(OH)3 precursor slurry is subjected to membrane separation washing and spray drying to obtain indium hydroxide powder. Figure 2 This is the morphology of indium hydroxide powder prepared by ammonia. The original morphology is a long rod with a diameter of 30-50nm and a length of about 200nm.

[0057] The indium hydroxide powder was calcined at 1000℃ for 120min to obtain nano-scale In2O3 powder. Figure 3 (a). Figure 3 (a) It can be seen that the indium oxide powder particles are uniform in size and well dispersed, with a diameter of about 2 to 3 μm, and the measured BET is 12 m 2 / g (original particle size is about 70nm).

[0058] Weigh 50 g of In(OH)3 powder, 850 g of In2O3 powder, 100 g of WO3 powder and 1000 g of pure water into a high-energy ball mill for ball milling. The ball milling speed is controlled at 60 r / min and the ball milling time is 24 h. No organic additives are required. Then, IWO granulated powder is obtained by spray granulation. The particle size of the granulated powder is D 50 The granulated powder is pressed into a steel or carbide mold at a pressure of 25 MPa for 20 seconds to obtain an IWO green body. The green body is then sintered in an oxygen atmosphere furnace. The sintering process is as follows: heating to 800°C at a heating rate of 60°C / h, holding for 60 minutes, and an oxygen flow rate of 10 L / min; then heating to 1200°C at a heating rate of 100°C / h, holding for 60 minutes, and an oxygen flow rate of 20 L / min; then heating to 1450°C at a heating rate of 200°C / h, holding for 300 minutes, and an oxygen flow rate of 30 L / min. After the maximum temperature is reached, the furnace is cooled naturally to obtain IWO particles. The IWO target obtained by this method has a good shape and a dark green color. The relative density, as determined by the dimensional method, is 60.7%. XRD detection shows that the phase structure is a single-phase indium oxide structure with a purity of 99.95%. The cross-sectional SEM shows that the grain size is about 5μm and the pores are evenly distributed. Figure 4 shown.

[0059] Comparative Example 1:

[0060] The reaction vessel used is a stainless steel reactor with a PTFE-lined inner wall and a capacity of 500L. 3+The concentration is 1 mol / L, the initial pH value is controlled below 0.5, and the initial temperature is 75°C; ammonia water is used for precipitation reaction, and the pH value is terminated at 8.5 after the reaction; after the precipitation reaction is completed, the temperature is kept and stirred for 120 minutes to obtain In(OH)3 precursor slurry. After washing, drying, and calcination, nano-scale In2O3 powder is obtained, such as Figure 3 (b) is shown. Figure 3 (b) It can be seen that the indium oxide powder particles are of different sizes and are severely agglomerated. The diameter of the powder particles is about 1 to 20 μm, and the measured BET is 20 m 2 / g (original particle size is about 42nm).

[0061] IWO particles were obtained by mixing, ball milling, granulation, molding, and sintering according to the method described in Example 1. The resulting IWO target material had a well-defined shape and a light green color. The relative density, as determined by the sizing method, was 55.3%. XRD analysis revealed a single-phase indium oxide structure, and cross-sectional SEM analysis revealed a grain size of approximately 5 μm.

[0062] Example 2:

[0063] The reaction vessel used is a stainless steel reactor with a PTFE-lined inner wall and a capacity of 500L. 3+ The concentration is 1 mol / L, the initial pH value is controlled below 0.5, and the initial temperature is 75°C; ammonia gas is introduced for precipitation reaction, and the ammonia gas flow rate is 2L / min; the pH is terminated at 8.5 after the reaction; after the precipitation reaction, the temperature is kept warm and stirred for 120 minutes to obtain In(OH)3 precursor slurry. After washing, drying, and calcination, nano-scale In2O3 powder is obtained. The indium oxide powder has a uniform particle size and good dispersion, with a diameter of about 2 to 5μm, and a BET of 4m 2 / g (original particle size is about 210nm).

[0064] IWO particles were obtained by mixing, ball milling, granulation, molding, and sintering according to the method described in Example 1. The resulting IWO target material had a well-defined shape and a light green color. The relative density, as determined by the sizing method, was 63.8%. XRD analysis revealed a single-phase indium oxide structure, and cross-sectional SEM analysis revealed a grain size of approximately 5 μm.

[0065] Example 3:

[0066] In(OH)3 powder and In2O3 powder were prepared according to Example 1.

[0067] 200 g of In(OH)3 powder, 790 g of In2O3 powder, 10 g of WO3 powder, and 1000 g of pure water were mixed, ball-milled, granulated, molded, and sintered according to the method described in Example 1 to produce IWO particles. The resulting IWO target material had a well-defined shape and a light green color. The relative density, as determined by the sizing method, was 60.9%. XRD analysis revealed a single-phase indium oxide structure, and cross-sectional SEM analysis revealed a grain size of approximately 5 μm.

[0068] Comparative Example 2:

[0069] In(OH)3 powder and In2O3 powder were prepared according to Example 1.

[0070] 300 g of In(OH)3 powder, 693 g of In2O3 powder, 7 g of WO3 powder, and 1000 g of pure water were weighed and mixed, ball-milled, granulated, molded, and sintered according to the method in Example 1 to obtain IWO particles. The IWO target material obtained by this method has a good shape and a light green color. The relative density obtained by the size method is 53.7%. XRD analysis shows that the phase structure is a single-phase structure of indium oxide; cross-sectional SEM shows that the grain size is 5-10 μm and there are a large number of through pores, such as Figure 5 shown.

[0071] Comparative Example 3:

[0072] In(OH)3 powder and In2O3 powder were prepared according to Example 1.

[0073] 20 g of In(OH)3 powder, 882 g of In2O3 powder, 98 g of WO3 powder and 1000 g of pure water were weighed and mixed, ball-milled and granulated according to the method in Example 1. However, a complete IWO green body could not be obtained by dry molding.

[0074] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for preparing a tungsten-doped indium oxide target, characterized in that: The initial pH value of the indium metal salt solution is controlled to be ≤0.5, ammonia gas is introduced into the indium metal salt solution at 70-80° C. to carry out a gas-liquid precipitation reaction until the pH value is 8-9, the introduction of ammonia gas is stopped, and the solution is kept warm for 60-240 minutes to obtain an indium hydroxide precursor slurry, solid-liquid separation is performed to obtain indium hydroxide powder, the indium hydroxide powder is calcined to obtain indium oxide powder, the indium hydroxide powder, indium oxide powder, and tungsten oxide powder are wet-ball-milled to obtain a ball mill material, the ball mill material is granulated to obtain a granulated powder, the granulated powder is compacted to obtain a green compact, and the green compact is sintered in an oxygen atmosphere to obtain a tungsten-doped indium oxide target material. The flow rate of the ammonia gas into the indium metal salt solution is 2 to 10 L / min; The particle size D of the indium hydroxide powder 50 2~10 μm; The mass ratio of the indium hydroxide powder, indium oxide powder and tungsten oxide powder is 5-20: 79-85: 1-10; The particle size D of the granulated powder 50 40~60 μm; The sintering process is as follows: first, heating the temperature to 600-900°C at a heating rate of 10-200°C / h for a first-stage sintering, controlling the holding time during the first-stage sintering to be 30-100 min, and introducing an oxygen flow rate of 5-20 L / min; then, heating the temperature to 1100-1350°C at a heating rate of 60-200°C / h for a second-stage sintering, controlling the holding time during the second-stage sintering to be 30-120 min, and introducing an oxygen flow rate of 10-30 L / min; and then heating the temperature to 1400-1500°C at a heating rate of 200-300°C / h for a third-stage sintering, controlling the holding time during the third-stage sintering to be 240-480 min, and introducing an oxygen flow rate of 20-50 L / min.

2. The method for preparing a tungsten-doped indium oxide target according to claim 1, wherein: The indium metal salt solution is selected from at least one of an indium chloride solution, an indium nitrate solution, and an indium sulfate solution; In the indium metal salt solution, In 3+ The concentration is 0.5~2.0 mol / L.

3. The method for preparing a tungsten-doped indium oxide target according to claim 1 or 2, wherein: The calcination temperature is 600-1100°C and the calcination time is 0.5-6h; The BET of the indium oxide powder is 4~12 m 2 / g, particle size is 70~210 nm.

4. The method for preparing a tungsten-doped indium oxide target according to claim 1 or 2, wherein: The ball milling medium is water, and during the wet ball milling, the ratio of the mass of the added ball milling medium to the total mass of the indium hydroxide powder, the indium oxide powder and the tungsten oxide powder is 30-60:40-70; The rotation speed of the wet ball milling is 30 to 100 r / min, and the wet ball milling time is 12 to 48 hours.

5. The method for preparing a tungsten-doped indium oxide target according to claim 1 or 2, wherein: The pressing pressure is 20-30 MPa, and the holding time is 10-30 s.

6. A tungsten-doped indium oxide target prepared by the preparation method according to any one of claims 1 to 5.

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