Gallium-cerium co-doped ITO target material and preparation method thereof

Abstract

The invention discloses a gallium-cerium co-doped ITO target material and a preparation method thereof, and belongs to the field of transparent conductive oxide ceramic target materials, and the preparation method comprises the following steps: weighing indium oxide powder raw materials, tin oxide powder raw materials, gallium oxide powder raw materials and cerium oxide powder raw materials in proportion, and performing pretreatment; the raw material powder is subjected to independent ball milling till the raw materials reach the preset particle size; mixing the four kinds of slurry, and continuously performing ball milling to obtain uniform mixed slurry; adding a binder into the mixed slurry, and carrying out ball milling and mixing to form stable formed slurry; carrying out spray granulation on the formed slurry to obtain spherical precursor powder; pressing and forming the precursor powder to obtain a biscuit, then putting the biscuit into a sintering furnace, carrying out stepped sintering in an oxygen atmosphere, and naturally cooling to obtain the gallium-cerium co-doped ITO target material. According to the gallium-cerium co-doped ITO target material prepared by the method, the relative density is greater than or equal to 99.4%, the resistivity is less than or equal to 99.4%, and the three-point bending strength is greater than or equal to 230MPa.

Description

Technical Field

[0001] This invention relates to the field of functional ceramic materials and transparent conductive oxides (TCOs), and in particular to a gallium-cerium co-doped ITO target and its preparation method. Background Technology

[0002] Indium tin oxide (ITO) is a ternary composite n-type semiconductor functional material composed of indium, tin, and oxygen. Due to its excellent optical transparency and electrical conductivity, it has become an indispensable transparent electrode material in high-end optoelectronic devices such as liquid crystal displays (LCDs), organic light-emitting diodes (OLEDs), touchscreens, and solar cells. In the ITO material system, indium oxide (… The indium site is the main component, with tin (Sn) acting as a dopant, occupying the indium sites and providing free electrons, which is the main source of its high conductivity. In addition, during the sintering process of the target material, a certain concentration of oxygen vacancies is inevitably generated, and these oxygen vacancies can also contribute charge carriers (electrons).

[0003] However, this traditional doping and defect control mechanism has inherent limitations: ITO itself is a highly doped degenerate semiconductor with a already high carrier (electron) concentration, and further increasing the carrier concentration has little effect on reducing resistivity. Conversely, excessive oxygen vacancies form high-density lattice defects, significantly increasing electron scattering and leading to a decrease in carrier mobility, which in turn hinders further reduction in resistivity. Therefore, the key to optimizing the conductivity of ITO lies in controlling the oxygen vacancy concentration to improve carrier mobility, rather than simply increasing the number of carriers. Meanwhile, ITO targets are prone to abnormal grain growth during high-temperature sintering, forming coarse grain structures. This results in uneven material density and insufficient mechanical strength, making them susceptible to cracking or fracture during subsequent transportation, installation, and sputtering, affecting production yield and target lifespan. Traditional single-element doping strategies cannot effectively solve the contradictory problem of optimizing electrical performance and improving mechanical strength simultaneously.

[0004] To address the aforementioned issues, various improvement solutions have been proposed within the industry, primarily focusing on multi-element doping and process control. For example, Chinese invention patent CN117285343A discloses a method for preparing ITO targets using ternary co-doping with lanthanum (La), erbium (Er), and cerium (Ce). This technology aims to optimize the microstructure by introducing multiple rare earth elements, ultimately achieving high optical transmittance and low resistivity. The target material demonstrates the potential of multi-component doping in performance regulation.

[0005] Another Chinese invention patent, CN119774982A, focuses on single doping, employing cerium (Ce) single doping to improve the resistivity and porosity of indium oxide targets. The design goal of this technology is clearly aimed at meeting the specific requirements of physical vapor deposition (such as evaporation) processes for the resistivity and density of the target material, rather than primarily aiming to improve the mechanical strength of the target material or reduce its resistivity.

[0006] Despite some progress in existing technologies, there are still significant shortcomings:

[0007] First, as disclosed in Chinese invention patent CN117285343A, even with ternary co-doping, the target resistivity obtained is ( For advanced optoelectronic devices that currently pursue higher performance and lower energy consumption, there is still considerable room for improvement. More importantly, this approach mainly relies on rare earth elements to regulate the pinning and scattering effects on grain boundaries, without effectively introducing or utilizing elements with unique electronic structures and bonding properties, such as gallium (Ga), to synergistically enhance the conductivity mechanism. In particular, its potential in optimizing carrier mobility has not been fully explored.

[0008] Secondly, the functional orientation of existing technical solutions is relatively singular. For example, the technical solution disclosed in Chinese invention patent CN119774982A aims to improve resistivity and porosity, which runs counter to the mainstream sputtering process's requirement for highly conductive and dense targets. Its goal is to meet specific process requirements rather than to resolve the contradiction between the "strength and conductivity" of conventional ITO targets. Overall, existing technologies lack a doping strategy and preparation scheme that can systematically and synergistically control carrier mobility and grain growth to simultaneously achieve high conductivity (low resistivity) and high mechanical strength. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to provide a gallium-cerium co-doped ITO target and its preparation method, which effectively suppresses abnormal grain growth, improves the density and strength of the target, and significantly optimizes carrier mobility and reduces resistivity.

[0010] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0011] A method for preparing a gallium-cerium co-doped ITO target includes the following steps:

[0012] Step 1: Raw material preparation and pretreatment: Weigh indium oxide, tin oxide, gallium oxide and cerium oxide powder raw materials according to the proportion, and perform drying pretreatment;

[0013] Step 2, Step-by-step ball milling process:

[0014] 2.1 Single ball milling: Indium oxide, tin oxide, gallium oxide and cerium oxide powders are mixed with dispersion media and ball milled separately until each raw material slurry reaches the predetermined particle size;

[0015] 2.2 Secondary ball milling: Mix the four slurries obtained in step 2.1 and continue ball milling for 1-5 hours to obtain a uniform mixed slurry;

[0016] 2.3 Three-stage ball milling: Add a 10% polyvinyl alcohol (PVA) solution as a binder to the mixed slurry, and ball mill for 4-10 hours to form a stable molding slurry;

[0017] Step 3, spray granulation: The molded slurry is fed into a spray drying equipment for spray granulation to obtain spherical precursor powder with good flowability;

[0018] Step 4, Forming and Sintering: The precursor powder is pressed into a blank, and then the blank is placed in a sintering furnace and sintered in a stepwise manner under an oxygen atmosphere to obtain the gallium-cerium co-doped ITO target.

[0019] A further improvement of the technical solution of the present invention is that, in step 1, the amount of each raw material used is as follows by weight: 100 parts of indium oxide, 8-12 parts of tin oxide, 0.2-3 parts of gallium oxide, and 0.1-0.5 parts of cerium oxide.

[0020] A further improvement to the technical solution of this invention is that, in step 2.1, the D50 particle size ranges of each raw material slurry after one ball milling are as follows:

[0021] Indium oxide slurry: 0.1μm~0.15μm;

[0022] Tin oxide paste: 0.17μm~0.25μm;

[0023] Gallium oxide paste: 0.25μm~0.3μm;

[0024] Cerium oxide slurry: 0.1μm~0.15μm.

[0025] A further improvement of the technical solution of the present invention is that, in step 2.1, the mass ratio of balls to material in the separate ball mill is 2:1 to 5:1, and the rotation speed is 200 to 400 r / min.

[0026] A further improvement of the technical solution of the present invention is that, in step 3, the process conditions for spray granulation are: inlet temperature of 180~220℃ and spray pressure of 0.1~0.2 MPa.

[0027] A further improvement to the technical solution of the present invention is that, in step 4, the pressing and molding specifically includes:

[0028] First, the precursor powder is pre-compressed under a pressure of 20–40 MPa to obtain a pre-compressed preform.

[0029] Then, the pre-pressed green blank is placed in a cold isostatic press and densified under a pressure of 150–300 MPa to obtain the final green blank.

[0030] A further improvement of the technical solution of the present invention is that, in step 4, the specific procedure of the stepped sintering is as follows: sintering is carried out in an oxygen atmosphere by a programmed temperature increase, and the temperature is held at least in the following temperature ranges: First temperature range: 900-1100 ℃, held for 1-3 hours; Second temperature range: 1200-1300 ℃, held for 1-3 hours; Third temperature range: 1450-1600 ℃, held for 2-10 hours.

[0031] A further improvement of the technical solution of the present invention is that: in step 4, the oxygen volume concentration in the oxygen atmosphere is 100%.

[0032] A further improvement to the technical solution of the present invention is that: after the stepped sintering is completed, the gallium-cerium co-doped ITO target material is naturally cooled down.

[0033] A gallium-cerium co-doped ITO target, wherein the physical properties of the gallium-cerium co-doped ITO target satisfy the following: relative density ≥ 99.4%, resistivity ≤ Three-point bending strength ≥230MPa.

[0034] The technological advancements achieved by this invention due to the adoption of the above technical solutions are as follows:

[0035] 1. This invention, through co-doping with Ga and Ce in a specific ratio and coupled with a refined preparation process, successfully overcomes the challenge of the inherent trade-off between reducing resistivity and increasing strength in traditional doping techniques. The resulting target material achieves high levels of key performance indicators: relative density ≥ 99.4%, resistivity ≤ With a three-point bending strength ≥230 MPa, the overall performance is significantly improved, achieving an excellent balance between low resistivity and high mechanical strength for the first time.

[0036] 2. Gallium oxide in this invention ( The introduction of ) because of its The large bond energy with oxygen effectively suppresses the excessive generation of oxygen vacancies, reduces carrier trapping, and thus significantly improves carrier mobility, playing a dominant role in reducing the resistivity of the target material; cerium oxide ( The addition of ) can effectively pin the grain boundaries and strongly suppress the abnormal growth of grains during high-temperature sintering, thereby refining the microstructure. This is the fundamental reason why the mechanical strength of the target material can be greatly improved. By precisely controlling the addition ratio of the two dopants, their positive effects are optimized and the potential negative effects (such as the increase in resistance caused by excessive Ce) are suppressed.

[0037] 3. The "stepwise ball milling-mixing" slurry treatment method provided by the present invention ensures the uniform dispersion of each component, especially the trace dopants; the spray granulation process obtains spherical precursor powder with good flowability, which is beneficial to subsequent molding to obtain high-density green blanks; the step-by-step sintering system under pure oxygen atmosphere provides ideal conditions for uniform grain growth and densification.

[0038] 4. The preparation method provided by this invention has a clear process route and controllable parameters, which can effectively remove pores and improve the density of the target material, providing a reliable technical solution for the stable preparation of high-performance co-doped ITO targets. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a flowchart of a method for preparing a gallium-cerium co-doped ITO target provided by the present invention. Detailed Implementation

[0041] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification, claims and accompanying drawings of this invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such processes, methods, products or devices.

[0042] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0043] like Figure 1 As shown, a method for preparing a gallium-cerium co-doped ITO target includes the following steps:

[0044] Step 1: Raw material preparation and pretreatment: Weigh indium oxide, tin oxide, gallium oxide and cerium oxide powder raw materials according to the proportion, and perform drying pretreatment;

[0045] The amounts of each raw material, expressed in parts by weight, are as follows:

[0046] 100 parts of indium oxide; indium oxide is the matrix material, providing basic optoelectronic properties.

[0047] 8-12 parts of tin oxide; tin oxide provides charge carriers and ensures basic conductivity.

[0048] Gallium oxide 0.2 to 3 parts; gallium oxide controls the generation of oxygen vacancies, reduces lattice defects, and improves electron mobility, which is the key to high conductivity.

[0049] Cerium oxide 0.1-0.5 parts; Cerium oxide inhibits grain growth and refines the structure, which is the key to improving strength.

[0050] Synergistic effect mechanism:

[0051] (1) Ga 3+ The bond energy with oxygen is relatively large, which can suppress the generation of oxygen vacancies, thereby controlling gallium oxide (GaN) The addition ratio of gallium oxide (GaN) controls the generation of excess oxygen vacancies, reduces carrier traps and defect energy levels, thereby improving carrier mobility. Although the addition of ) reduces the carrier concentration, it increases the carrier mobility. Overall, the increase in carrier mobility has the main effect on the resistivity of the target material, ultimately achieving the effect of reducing the resistivity of the target material.

[0052] (2) The presence of Ce can effectively pin grain boundaries, inhibit grain migration and growth at high temperatures, refine grains, and increase strength. However, excessive Ce will increase the resistivity of the material. By controlling the amount of cerium oxide (Ce), The addition ratio of [specific ingredient] allows the target material to achieve a strength of over 230 MPa while meeting the resistivity requirements.

[0053] (3) The combined effect of gallium oxide and cerium oxide (Ce) achieves low resistivity (≤ () and the unity of high intensity.

[0054] Step 2, Step-by-step ball milling process:

[0055] 2.1 Single ball milling: Indium oxide, tin oxide, gallium oxide and cerium oxide powders are mixed with dispersion media and ball milled separately until each raw material slurry reaches the predetermined particle size;

[0056] The ball-to-material mass ratio for ball milling is (2~5):1, and the rotation speed is 200~400 r / min.

[0057] The D50 particle size ranges of each raw material slurry after one ball milling are as follows:

[0058] Indium oxide slurry: 0.1μm~0.15μm;

[0059] Tin oxide paste: 0.17μm~0.25μm;

[0060] Gallium oxide paste: 0.25μm~0.3μm;

[0061] Cerium oxide slurry: 0.1μm~0.15μm.

[0062] 2.2 Secondary ball milling: Mix the four slurries obtained in step 2.1 and continue ball milling for 1-5 hours to obtain a uniform mixed slurry;

[0063] 2.3 Three-stage ball milling: Add a 10t% polyvinyl alcohol (PVA) solution as a binder to the mixed slurry, and ball mill for 4-10 hours to form a stable molding slurry;

[0064] Step 3, spray granulation: The molded slurry is fed into a spray drying equipment for spray granulation to obtain spherical precursor powder with good flowability;

[0065] The process conditions for spray granulation are: inlet temperature is... The spray pressure is 0.1~0.2 MPa.

[0066] Step 4, Forming and Sintering: The precursor powder is pressed into a blank, and then the blank is placed in a sintering furnace and sintered in a stepwise manner under an oxygen atmosphere (oxygen volume concentration of 100%) to finally obtain gallium-cerium co-doped ITO target.

[0067] (1) Press molding specifically includes:

[0068] First, the precursor powder is pre-compressed under a pressure of 20–40 MPa to obtain a pre-compressed green body.

[0069] Then, the pre-pressed green blank is placed in a cold isostatic press and densified under a pressure of 150–300 MPa to obtain the final green blank.

[0070] (2) The specific procedure for stepped sintering is as follows: sintering is carried out in an oxygen atmosphere (oxygen volume concentration of 100%) using a programmed temperature increase method, and the temperature is maintained at least in the following temperature ranges: First temperature range: Keep warm for 1-3 hours; Second temperature range: Keep warm for 1-3 hours; Third temperature range: Keep warm for 2 to 10 hours.

[0071] After the stepped sintering is completed, the gallium-cerium co-doped ITO target is allowed to cool down naturally.

[0072] The prepared gallium-cerium co-doped ITO target material meets the following physical properties: relative density ≥ 99.4%, resistivity ≤ Three-point bending strength ≥230MPa.

[0073] Example 1

[0074] A method for preparing a gallium-cerium co-doped ITO target includes the following steps:

[0075] Step 1, Raw material preparation and pretreatment: Weigh 9 kg of indium oxide, 1 kg of tin oxide, 100 g of gallium oxide, and 30 g of cerium oxide powder raw materials, and perform drying pretreatment;

[0076] Step 2, Step-by-step ball milling process:

[0077] 2.1 Single ball milling: The four raw materials were ground separately using a planetary ball mill in a single ball milling process to grind the indium oxide slurry to a particle size of D50=0.145μm, the gallium oxide slurry to a particle size of D50=0.261μm, the tin oxide slurry to a particle size of D50=0.203μm, and the cerium oxide slurry to a particle size of D50=0.124μm.

[0078] 2.2 Secondary ball milling: The four slurries obtained in step 2.1 are mixed together and ball milled a second time using a rolling mill for 3 hours to ensure uniform mixing and obtain a homogeneous mixed slurry;

[0079] 2.3 Three-stage ball milling: Add 101.3g of 10% polyvinyl alcohol (PVA) solution as a binder to the mixed slurry, and mix by rolling ball milling for 5 hours to form a stable molding slurry;

[0080] Step 3, spray granulation: The molded slurry is fed into a spray drying equipment for spray granulation to obtain spherical precursor powder with good flowability;

[0081] Step 4, Molding and Sintering: The precursor powder is dry-pressed at 30MPa and then cold isostatically pressed at 200MPa to form a target blank with a diameter of 200mm.

[0082] The green blanks are then placed in a sintering furnace and sintered in a 100% oxygen atmosphere. Gallium-cerium co-doped ITO target material was obtained.

[0083] Example 2

[0084] A method for preparing a gallium-cerium co-doped ITO target includes the following steps:

[0085] Step 1, Raw material preparation and pretreatment: Weigh 9 kg of indium oxide, 1 kg of tin oxide, 18 g of gallium oxide, and 9 g of cerium oxide powder raw materials, and perform drying pretreatment;

[0086] Step 2, Step-by-step ball milling process:

[0087] 2.1 Single ball milling: The four raw materials were ground separately using a planetary ball mill in a single ball milling process to grind the indium oxide slurry to a particle size of D50=0.1μm, the gallium oxide slurry to a particle size of D50=0.25μm, the tin oxide slurry to a particle size of D50=0.17μm, and the cerium oxide slurry to a particle size of D50=0.14μm.

[0088] 2.2 Secondary ball milling: The four slurries obtained in step 2.1 are mixed together and ball milled a second time using a rolling mill for 1 hour to make the slurries uniformly mixed and obtain a uniform mixed slurry;

[0089] 2.3 Three-stage ball milling: Add 101.3g of 10% polyvinyl alcohol (PVA) solution to the mixed slurry as a binder, and mix by rolling ball milling for 4 hours to form a stable molding slurry;

[0090] Step 3, spray granulation: The molded slurry is fed into a spray drying equipment for spray granulation to obtain spherical precursor powder with good flowability;

[0091] Step 4, Molding and Sintering: The precursor powder is dry-pressed at 20MPa and then cold isostatically pressed at 150MPa to form a target blank with a diameter of 200mm.

[0092] The green blanks are then placed in a sintering furnace and sintered in an oxygen atmosphere. Keep warm for 1 hour. Keep warm for 2 hours. After holding at the temperature for 2 hours and then naturally cooling, gallium-cerium co-doped ITO target material is obtained.

[0093] Example 3

[0094] A method for preparing a gallium-cerium co-doped ITO target includes the following steps:

[0095] Step 1, Raw material preparation and pretreatment: Weigh 9 kg of indium oxide, 1 kg of tin oxide, 270 g of gallium oxide, and 45 g of cerium oxide powder raw materials, and perform drying pretreatment;

[0096] Step 2, Step-by-step ball milling process:

[0097] 2.1 Single ball milling: The four raw materials were ground separately using a planetary ball mill to achieve a particle size of D50=0.15μm for indium oxide, D50=0.3μm for gallium oxide, D50=0.25μm for tin oxide, and D50=0.15μm for cerium oxide.

[0098] 2.2 Secondary ball milling: The four slurries obtained in step 2.1 are mixed together and ball milled a second time using a rolling mill for 5 hours to ensure uniform mixing and obtain a homogeneous mixed slurry;

[0099] 2.3 Three-stage ball milling: Add 101.3g of 10% polyvinyl alcohol (PVA) solution as a binder to the mixed slurry, and ball mill for 10 hours to form a stable molding slurry;

[0100] Step 3, spray granulation: The molded slurry is fed into a spray drying equipment for spray granulation to obtain spherical precursor powder with good flowability;

[0101] Step 4, Molding and Sintering: The precursor powder is dry-pressed at 40MPa and then cold isostatically pressed at 300MPa to form a target blank with a diameter of 200mm.

[0102] The green blanks are then placed in a sintering furnace and sintered in an oxygen atmosphere. Keep warm for 3 hours. Keep warm for 3 hours. After holding at a temperature for 10 hours and then naturally cooling, gallium-cerium co-doped ITO target material is obtained.

[0103] Comparative Example 1

[0104] A method for preparing a gallium-cerium co-doped ITO target includes the following steps:

[0105] (1) Ingredients: Weigh out 9 kg of indium oxide, 1 kg of tin oxide, 100 g of gallium oxide and 30 g of cerium oxide.

[0106] (2) Stepwise ball milling: The four raw materials were ground separately using a planetary ball mill to perform a first ball milling, grinding the indium oxide slurry to D50=0.221μm, the gallium oxide slurry to D50=0.355μm, the tin oxide slurry to D50=0.273μm, and the cerium oxide slurry to D50=0.222μm; the four slurries were mixed together and ball milled a second time using a rolling mill for 3 hours to make the slurry uniform; 101.3g of 10% PVA solution was added to the mixed slurry and ball milled for 5 hours.

[0107] (3) Granulation and molding: After spray granulation, the slurry is dry-pressed at 30MPa and then cold isostatically pressed at 200MPa to form a target blank with a diameter of 200mm.

[0108] (4) Step sintering: The green blank is sintered in an oxygen atmosphere. Keep warm for 2 hours. Keep warm for 1 hour. Keep warm for 5 hours.

[0109] Comparative Example 2

[0110] A method for preparing a gallium-cerium co-doped ITO target includes the following steps:

[0111] (1) Ingredients: Weigh out 9 kg of indium oxide, 1 kg of tin oxide, 100 g of gallium oxide and 30 g of cerium oxide.

[0112] (2) Stepwise ball milling: The four raw materials were ground separately using a planetary ball mill. The particle size of the indium oxide slurry was ground to D50=0.145μm, the gallium oxide slurry to D50=0.261μm, the tin oxide slurry to D50=0.203μm, and the cerium oxide slurry to D50=0.124μm. The four slurries were mixed together and ball milled a second time using a rolling mill for 3 hours to make the slurry uniform. 101.3g of 10% PVA solution was added to the mixed slurry and ball milled for 5 hours.

[0113] (3) Granulation and molding: After spray granulation, the slurry is dry-pressed at 30MPa and then cold isostatically pressed at 200MPa to form a target blank with a diameter of 200mm.

[0114] (4) Direct sintering: The green blank is sintered in an oxygen atmosphere. Previously, there was no insulation section. Keep warm for 5 hours.

[0115] Comparative Example 3

[0116] A method for preparing a gallium-cerium co-doped ITO target includes the following steps:

[0117] (1) Ingredients: Weigh out 9 kg of indium oxide and 1 kg of tin oxide.

[0118] (2) Stepwise ball milling: The two raw materials were ground separately using a planetary ball mill to grind the indium oxide to D50=0.141μm and the tin oxide to D50=0.209μm. The two slurries were mixed together and then ball milled a second time using a rolling mill for 3 hours to make the slurry uniform. 1000g of 10% PVA solution was added to the mixed slurry and the mixture was ball milled for 5 hours.

[0119] (3) Granulation and molding: After spray granulation, the slurry is dry-pressed at 30MPa and then cold isostatically pressed at 200MPa to form a target blank with a diameter of 200mm.

[0120] (4) Stage sintering: The green blank is sintered in an oxygen atmosphere. Keep warm for 2 hours. Keep warm for 1 hour. Keep warm for 5 hours.

[0121] The gallium-cerium co-doped ITO target samples prepared in Examples 1-3 and Comparative Examples 1-3 were tested, and their relative density, three-point bending strength, and resistivity were compared. The results are shown in Table 1 below:

[0122] Table 1. Detection results of gallium-cerium co-doped ITO target samples prepared in Examples 1-3 and Comparative Examples 1-3.

[0123]

[0124] As can be seen from the experimental data comparison in Table 1 above, ITO targets prepared using traditional methods (such as Comparative Examples 1-3) cannot simultaneously achieve low resistivity, high mechanical strength, and high density when key process parameters deviate from the design range of this invention (including raw material particle size not being within a specific range after one ball milling, the sintering process not using a step-by-step procedure, or the absence of gallium oxide and cerium oxide in the raw materials). Only by using the gallium-cerium co-doping formulation, step-by-step ball milling process, and step-by-step sintering method provided by this invention (such as Examples 1-3) can the prepared ITO targets achieve excellent comprehensive performance: resistivity lower than The flexural strength is not less than 230 MPa, and the relative density is higher than 99.4%. This indicates that the technical solution of the present invention has a synergistic optimization effect on each key process and is a necessary condition for obtaining high-performance target materials.

[0125] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a gallium-cerium co-doped ITO target, characterized in that, Includes the following steps: Step 1: Raw material preparation and pretreatment: Weigh indium oxide, tin oxide, gallium oxide and cerium oxide powder raw materials according to the proportion, and perform drying pretreatment; Step 2, Step-by-step ball milling process: 2.1 Single ball milling: Indium oxide, tin oxide, gallium oxide and cerium oxide powders are mixed with dispersion media and ball milled separately until each raw material slurry reaches the predetermined particle size; 2.2 Secondary ball milling: Mix the four slurries obtained in step 2.1 and continue ball milling for 1-5 hours to obtain a uniform mixed slurry; 2.3 Three-stage ball milling: Add a 10% polyvinyl alcohol solution as a binder to the mixed slurry, and ball mill for 4-10 hours to form a stable molding slurry; Step 3, spray granulation: The molded slurry is fed into a spray drying equipment for spray granulation to obtain spherical precursor powder with good flowability; Step 4, Forming and Sintering: The precursor powder is pressed into a blank, and then the blank is placed in a sintering furnace and sintered in a stepwise manner under an oxygen atmosphere to obtain the gallium-cerium co-doped ITO target.

2. The preparation method according to claim 1, characterized in that, In step 1, the amounts of each raw material are as follows by weight: 100 parts indium oxide, 8-12 parts tin oxide, 0.2-3 parts gallium oxide, and 0.1-0.5 parts cerium oxide.

3. The preparation method according to claim 1, characterized in that, In step 2.1, the D50 particle size ranges of each raw material slurry after one ball milling are as follows: Indium oxide slurry: 0.1μm~0.15μm; Tin oxide paste: 0.17μm~0.25μm; Gallium oxide paste: 0.25μm~0.3μm; Cerium oxide slurry: 0.1μm~0.15μm.

4. The preparation method according to claim 1, characterized in that, In step 2.1, the ball-to-material mass ratio of the individual ball mill is 2:1 to 5:1, and the rotation speed is 200 to 400 r / min.

5. The preparation method according to claim 1, characterized in that, In step 3, the process conditions for spray granulation are: inlet temperature of 180~220℃ and spray pressure of 0.1~0.2MPa.

6. The preparation method according to claim 1, characterized in that, In step 4, the pressing and molding specifically includes: First, the precursor powder is pre-compressed under a pressure of 20–40 MPa to obtain a pre-compressed preform. Then, the pre-pressed green blank is placed in a cold isostatic press and densified under a pressure of 150–300 MPa to obtain the final green blank.

7. The preparation method according to claim 1, characterized in that, In step 4, the specific procedure for the stepped sintering is as follows: sintering is carried out in an oxygen atmosphere using a programmed temperature increase method, and the temperature is maintained at least in the following temperature ranges: First temperature range: 900-1100 ℃, maintained for 1-3 hours; Second temperature range: 1200-1300 ℃, maintained for 1-3 hours; Third temperature range: 1450-1600 ℃, maintained for 2-10 hours.

8. The preparation method according to claim 1 or 7, characterized in that, In step 4, the oxygen volume concentration in the oxygen atmosphere is 100%.

9. The preparation method according to claim 1 or 7, characterized in that, After the stepped sintering is completed, the gallium-cerium co-doped ITO target is naturally cooled down.

10. A gallium-cerium co-doped ITO target, prepared by the method according to any one of claims 1-9, characterized in that, The physical properties of the gallium-cerium co-doped ITO target satisfy the following: relative density ≥ 99.4%, resistivity ≤ Three-point bending strength ≥230MPa.

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