High-mobility indium-oxide-based target material, and preparation method therefor and use thereof

Abstract

The present application belongs to the technical field of target materials for photovoltaic cells, and particularly discloses a high-mobility indium-oxide-based target material, and a preparation method therefor and the use thereof. Raw materials for the preparation of the indium-oxide-based target material of the present application comprise indium oxide, an oxide X, an oxide Y and an oxide Z, wherein the oxide X comprises at least one of Y2O3, Dy2O3 and Gd2O3; the oxide Y comprises at least one of B2O3 and Bi2O3; and the oxide Z comprises at least one of Ta2O5, MoO3 and WO3. The indium-oxide-based target material has a relatively low maximum sintering temperature and a relatively high density. In the present application, the indium-oxide-based target material having a high density and a relatively low grain size is obtained under the conditions of a relatively low doping amount and a relatively low sintering temperature. A TCO film obtained from coating using the indium-oxide-based target material has high light transmittance and a high carrier mobility, can be used in an HJT battery, and improves the photoelectric conversion efficiency.

Description

A high-mobility indium oxide-based target, its preparation method and application Technical Field

[0001] This application relates to the field of photovoltaic cell target technology, and in particular to an indium oxide-based target with high mobility, its preparation method and application. Background Technology

[0002] Silicon heterojunction solar cells (HJT cells) possess high theoretical efficiency, simple fabrication processes, and significant potential for cost reduction, making them a current research hotspot and a key area for large-scale industrialization in the solar cell field. Transparent conductive oxide (TCO) films, with their excellent conductivity and high light transmittance, are the core material for HJT cells and crucial for ensuring high photoelectric conversion efficiency.

[0003] Currently, TCO thin films used in HJT batteries are mainly prepared by magnetron sputtering deposition using In2O3-based targets. The In2O3 content in these targets is mostly 90wt%-99wt%. By controlling the type and content of doping elements, TCO thin films with different photoelectric properties can be obtained. With the development of the HJT battery industry, higher technical indicators for the carrier mobility and transmittance of TCO thin films have been proposed to achieve higher conversion efficiency in HJT batteries. The carrier mobility of TCO thin films prepared with pure In2O3 targets can reach 150 cm⁻¹. 2 The per-v·s ratio of In₂O₃ is significantly higher than that of currently commercially available TCO thin films. However, the high melting point of In₂O₃ (2000℃) necessitates a sintering temperature exceeding 1800℃ for its target material, drastically increasing energy consumption, production costs, and equipment requirements. Traditional In₂O₃-based targets are typically doped with SnO₂ to aid sintering, lowering the sintering temperature and increasing carrier concentration. However, SnO₂'s sintering aid effect is generally limited, requiring higher doping levels to achieve a better effect. Furthermore, in TCO thin films, carrier mobility is affected by scattering between electrons and dopant ions. Increasing the doping level increases scattering during carrier movement, significantly reducing carrier mobility and negatively impacting light transmittance. Currently, there is a lack of commercially available solutions for low-doped In₂O₃-based targets that possess both high carrier mobility and high light transmittance, and can be sintered densely at relatively low temperatures (≤1600℃).

[0004] Therefore, there is an urgent need to develop an In2O3-based target material with high carrier mobility, high transmittance, low doping, and high density that can be sintered at a lower temperature. At the same time, it is necessary to solve the problem of the difficulty in uniformly and efficiently incorporating low-doped oxides into the matrix, so as to further improve the performance of TCO thin films and HJT batteries, and expand the application scope and prospects of TCO thin films. Summary of the Invention

[0005] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application provides an indium oxide-based target material. The indium oxide-based target material of this application has a low sintering temperature and high density. By doping with multiple oxides, this application achieves a highly dense target material with a small grain size at a low doping amount and sintering temperature. The TCO thin film obtained by coating using this indium oxide-based target material achieves high transmittance and high carrier mobility, improving the performance of the TCO thin film, and can be used in HJT cells to further improve the photoelectric conversion efficiency.

[0006] This application also provides a method for preparing an indium oxide-based target.

[0007] This application also provides a TCO film.

[0008] This application also provides a method for preparing a TCO thin film.

[0009] This application also provides applications of indium oxide-based targets.

[0010] In a first aspect, this application provides an indium oxide-based target material, the raw materials for which include indium oxide, X oxide, Y oxide and Z oxide;

[0011] Among them, the oxide X includes at least one of Y2O3, Dy2O3 and Gd2O3;

[0012] Y oxides include at least one of B2O3 and Bi2O3;

[0013] Z oxides include at least one of Ta2O5, MoO3 and WO3.

[0014] According to specific embodiments of this application, the indium oxide-based target provided by this application has at least the following beneficial effects:

[0015] The maximum sintering temperature of the indium oxide-based target material in this application does not exceed 1600℃, which can reduce energy consumption, production costs, and equipment requirements, making it more suitable for large-scale industrial production. The density of the indium oxide-based target material prepared in this application reaches over 98.5%, and the average grain size of the target material ranges from 6.3μm to 8.5μm. This application obtains highly dense target materials with low grain size by using various doping oxide additives. The TCO film obtained by coating the indium oxide-based target material prepared using the method of this application exhibits excellent performance, achieving high carrier mobility of 60cm³ while maintaining a relatively low carrier concentration. 2 With a transmittance of over / V·S and a transmittance of over 89% in the wavelength range of 400nm-1200nm, it can be used in HJT cells to further improve photoelectric conversion efficiency.

[0016] According to some embodiments of this application, the X oxide includes at least two of Y2O3, Dy2O3 and Gd2O3.

[0017] According to some embodiments of this application, the X oxide includes Y2O3, Dy2O3 and Gd2O3.

[0018] According to some embodiments of this application, the Y oxide includes B2O3 and Bi2O3.

[0019] This application uses X oxide and Z oxide as doping agents, utilizing their higher content than In. 3+ rare earth metal ions Y with radius 3+ Dy 3+ and Gd 3+ With the small-radius, high-valence element Ta in the Z oxide doping agent 5+ Mo 6+ and W 6+ Co-doping can effectively improve doping efficiency and the stability of the doped crystal, ensuring that the scattering centers of impurities are reduced with less doping, thereby improving carrier mobility.

[0020] Specifically, oxide X has higher doping activity. When incorporated into indium oxide, it causes lattice distortion, increases defects, and enlarges the cell volume. This makes it easier for smaller, high-valence ions in oxide Z to enter the indium oxide lattice and replace indium ions, thereby improving the doping efficiency. The two different types of doping oxides occupy different crystallographic positions of In in the cell, making the doping more symmetrical. Their effects on the cell volume are opposite, resulting in a smaller overall change in cell volume. The combined effect of the two oxides results in a smaller strain in the cell volume after doping, thereby improving the stability of the doped crystal.

[0021] In the cubic In₂O₃ unit cell, In has two crystallographic positions: the 8b position and the 24d position. The In atom at the 8b position has the same bond length as the six surrounding O atoms, but lacks two oxygen atoms along its body diagonal. The In atom at the 24d position has a different bond length than the six surrounding O atoms, and its missing oxygen atoms are distributed along its face diagonal. (Six-coordinated In) 3+ The radius is 0.094 nm, but the radius of high-valence ions (≥+5) is often less than 0.08 nm, for example, Ta. 5+ Mo 6+ W 6+ The radii are 0.078 nm, 0.073 nm, and 0.074 nm, respectively; this is similar to In 3+ Due to the significant difference in radii, the efficiency of high-valence ions being incorporated alone is relatively low. Therefore, this application further optimizes the doping scheme for low-doped indium oxide by selecting ions with higher doping activity and radii larger than In. 3+ rare earth ions Y with smaller radius differences 3+ (0.104nm), Dy 3+ (0.105nm), Gd 3+ (0.108nm) co-doping improves doping efficiency and crystal stability, enhances target quality, and can further improve carrier mobility and light transmittance of TCO films prepared from the target.

[0022] This application also found that when all three X oxides, Y2O3, Dy2O3 and Gd2O3, are doped, the prepared target material and TCO film have the best overall performance, and all performance data are good. The reasonable ratio of the three X oxides achieves a relatively better technical effect, which may be related to the special distribution of the outer electrons of rare earth ions.

[0023] In addition, the X oxide doping agent used in this application can also be used as a solid-state sintering aid. By reducing the sintering activation energy, it can appropriately reduce the sintering temperature. It can also promote mass transfer, densification, and improve doping efficiency by destroying the stability of the crystal structure of the indium oxide matrix material and generating lattice distortion or defects.

[0024] This application uses a γ-oxide doped agent as a liquid-phase sintering aid. It co-melts with the indium oxide matrix material at a relatively low temperature to form a liquid phase. The liquid phase fills pores and achieves densification at a lower sintering temperature through a "dissolution-precipitation" process. This application employs a combination of two sintering aids to achieve the optimal technical effect of reducing the maximum sintering temperature and promoting target densification.

[0025] According to some embodiments of this application, the indium oxide, the X oxide, the Y oxide, and the Z oxide are all powders.

[0026] According to some embodiments of this application, the median particle size range of the indium oxide powder is 0.31 μm < D50 < 0.45 μm, the median particle size range of the X oxide powder is 1.26 μm < D50 < 1.75 μm, the median particle size range of the Y oxide powder is 2.15 μm < D50 < 3.36 μm, and the median particle size range of the Z oxide powder is 1.86 μm < D50 < 3.15 μm.

[0027] According to some embodiments of this application, the raw materials for preparation include, by mass parts, 98.1-99.6 parts of indium oxide, 0.05-0.7 parts of oxide X, 0.05-0.7 parts of oxide Y and 0.05-0.6 parts of oxide Z.

[0028] According to some embodiments of this application, the raw materials for preparation include, by mass parts, 98.5-99.5 parts of indium oxide, 0.2-0.6 parts of oxide X, 0.2-0.4 parts of oxide Y and 0.1-0.5 parts of oxide Z.

[0029] According to some embodiments of this application, the raw materials for preparation include, by mass parts, 98.8-99.5 parts of indium oxide, 0.3-0.5 parts of oxide X, 0.2-0.4 parts of oxide Y and 0.2-0.5 parts of oxide Z.

[0030] According to some embodiments of this application, the raw materials for preparation also include dispersants, binders, plasticizers, and water.

[0031] According to some embodiments of this application, the raw materials for preparation further include 0.2-1 parts of dispersant, 0.1-0.3 parts of binder, 0.5-2 parts of plasticizer, and 100-200 parts of water.

[0032] According to some embodiments of this application, the dispersant is polyvinylpyrrolidone.

[0033] In the preparation process of indium oxide-based targets, the use of a dispersant helps to improve the uniformity of mixing of various oxide doping agents with the indium oxide matrix, thereby helping to improve doping activity.

[0034] According to some embodiments of this application, the adhesive includes at least one of polyvinyl alcohol, polyethylene oxide, and polyvinylidene fluoride.

[0035] According to some embodiments of this application, the plasticizer is polyethylene glycol.

[0036] A second aspect of this application provides a method for preparing the indium oxide-based target material described in the first aspect of this application, comprising the following steps:

[0037] S1: Mix the oxides of X, Y and Z, disperse and grind them, then add indium oxide and grind them again to obtain a mixed powder;

[0038] S2: Cold isostatic pressing, degreasing, and sintering yield indium oxide-based target material.

[0039] According to some embodiments of this application, in step S1, a dispersant and water are added before dispersion and grinding to obtain slurry 1; in step S1, indium oxide is added and ground to obtain slurry 2.

[0040] According to some embodiments of this application, the median particle size of the slurry 1 is controlled to be D50≤0.2μm.

[0041] According to some embodiments of this application, the median particle size of the slurry 2 is controlled to be D50≤0.13μm.

[0042] This application improves the doping uniformity and efficiency of doped oxide additives through a two-step mixing scheme. Combining the technical solution of this application with improvements to traditional processes, firstly, low-content doped oxides X, Y, and Z are pre-mixed and ball-milled to obtain slurry 1. The particle size of this slurry is then controlled to be smaller than that of indium oxide powder through further grinding. Next, the doped oxide powder is mixed with indium oxide powder, resulting in more thorough mixing, better sintering assistance, and a more uniform distribution of target elements. This effectively improves the doping activity of the doped oxides, thereby resulting in better uniformity and superior performance of the thin film prepared by magnetron sputtering. Through the improved preparation process, this application further enhances the performance of the target material and TCO thin film by more than 10%.

[0043] According to some embodiments of this application, the grinding is ball milling.

[0044] According to some embodiments of this application, the sintering in step S2 includes three stages;

[0045] The first stage sintering temperature is 600℃-800℃, and the holding time is 1h-5h.

[0046] The second stage sintering temperature is 900℃-980℃, and the holding time is 3h-8h;

[0047] The third stage involves sintering in an oxygen atmosphere at a temperature of 1450℃-1600℃ for 5-12 hours.

[0048] Preferably, the sintering temperature of the third stage is 1450℃-1550℃.

[0049] A third aspect of this application provides a TCO thin film prepared using the indium oxide-based target material described in the first aspect of this application, wherein the carrier concentration of the TCO thin film is 1.2 × 10⁻⁶. 20 cm-3 -2.8×10 20 cm -3 Carrier mobility ≥ 60 cm 2 / V·S, transmittance ≥89% in the wavelength range of 400nm-1200nm.

[0050] According to some embodiments of this application, the carrier concentration of the TCO thin film is 1.58 × 10⁻⁶. 20 cm -3 -2.65×10 20 cm -3 Carrier mobility ≥ 66.8 cm⁻¹ 2 / V·S, transmittance ≥89.6% in the wavelength range of 400nm-1200nm.

[0051] A fourth aspect of this application provides a method for preparing a TCO thin film as described in the third aspect of this application, comprising the following steps:

[0052] Using the target material described in the first aspect of this application, a TCO thin film is obtained by magnetron sputtering with a deposition power of 1kW-10kW and a deposition thickness of 20nm-200nm.

[0053] According to some embodiments of this application, the coating power is 3kW-8kW and the coating thickness is 60nm-120nm.

[0054] According to some embodiments of this application, the method for preparing the TCO thin film further includes an annealing step after coating, wherein the annealing step is annealing in a muffle furnace at a temperature of 150℃-250℃ for 20min-40min.

[0055] The fifth aspect of this application provides the application of the target material described in the first aspect of this application, or the preparation method described in the second aspect of this application, or the TCO thin film described in the third aspect of this application, or the preparation method described in the fourth aspect of this application, in the field of HJT batteries.

[0056] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing this application. Detailed Implementation

[0057] The following will clearly and completely describe the concept and technical effects of this application in conjunction with embodiments, so as to fully understand the purpose, features and effects of this application. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are all within the scope of protection of this application.

[0058] Unless otherwise specified in the detailed implementation method, the standard conditions or the manufacturer's recommended conditions shall be followed. All reagents or instruments used, unless otherwise specified, are commercially available standard products.

[0059] Example 1

[0060] This embodiment provides an indium oxide-based target with high mobility and low doping, and provides a method for its preparation.

[0061] The raw materials of the indium oxide-based target in this embodiment are as follows by mass: 99 parts In2O3, X oxides: 0.1 parts Dy2O3, 0.3 parts Y2O3 and 0.1 parts Gd2O3, Y oxides: 0.2 parts B2O3 and 0.1 parts Bi2O3, and Z oxide: 0.2 parts Ta2O5;

[0062] All raw materials are oxide powders with a purity of 4N or higher. The median particle size range of In2O3 powder is 0.31μm < D50 < 0.45μm, the median particle size range of X powder is 1.26μm < D50 < 1.75μm, the median particle size range of Y powder is 2.15μm < D50 < 3.36μm, and the median particle size range of Z powder is 1.86μm < D50 < 3.15μm.

[0063] The specific steps of the preparation method of the indium oxide-based target in this embodiment are as follows:

[0064] 1) Ball milling, mixing, and granulation of powders:

[0065] Powders X, Y, and Z were mixed, and 1.5 parts of deionized water and 0.005 parts of dispersant polyvinylpyrrolidone (PVP) were added. The mixture was ball-milled using a sand mill to obtain slurry 1. The ball milling time was 6 hours. The median particle size D50 of the mixed powder in slurry 1 was ≤0.20 μm.

[0066] In₂O₃ powder, 148.5 parts of deionized water, and 0.495 parts of PVP were added to slurry 1. Slurry 2 was obtained by ball milling using a sand mill for 7 hours. The median particle size D50 of slurry 2 was ≤0.13 μm.

[0067] Based on slurry 2, add 0.16 parts of binder (PVA) and 0.8 parts of plasticizer (PEG), mix well, and then spray granulate to obtain granulated powder.

[0068] 2) Forming of the unfinished blank:

[0069] Using a rotating target mold, granulated powder is injected into the mold, sealed, and placed in the hydraulic press chamber. The molding pressure is 185 MPa. After cold isostatic pressing, the powder is demolded to obtain the rotating target preform.

[0070] 3) Debinding and sintering:

[0071] After degreasing, the target blank was sintered in a sintering furnace: the first stage sintering temperature was 700℃, and the holding time was 3 hours; the second stage sintering temperature was 940℃, and the holding time was 5.5 hours; the third stage sintering was carried out at the highest temperature of 1520℃, with oxygen introduced at a rate of 42.5 L / min and a pressure of 2.35 kg / cm². 2 The material was kept at a temperature of 8.5 h in an oxygen atmosphere to obtain a dense indium oxide-based target.

[0072] This embodiment further provides a method for flaw detection and coating of the prepared indium oxide-based target material, the specific method of which is as follows:

[0073] Bonding flaw detection: The prepared rotating target coated with indium is bonded to the titanium tube and ultrasonic flaw detection is used, and no dark cracks are found.

[0074] TCO thin film deposition: On a cleaned glass substrate, a TCO thin film was deposited using magnetron sputtering at a power of 3kW and a film thickness of 90nm. The film was then annealed in an air atmosphere at 200°C for 30 minutes to obtain the TCO thin film, followed by performance testing.

[0075] Example 2

[0076] This embodiment provides an indium oxide-based target with high mobility and low doping, and provides a method for its preparation.

[0077] The difference between this embodiment and Embodiment 1 is that: in this embodiment, Z oxide is replaced with an equal amount of MoO3, and the highest sintering temperature in the third stage of the sintering process is 1480℃; other raw materials and preparation methods are the same as in Embodiment 1.

[0078] Example 3

[0079] This embodiment provides an indium oxide-based target with high mobility and low doping, and provides a method for its preparation.

[0080] The difference between this embodiment and Embodiment 1 is that in this embodiment, Z oxide is replaced with an equal amount of WO3, and the highest sintering temperature in the third stage of the sintering process is 1500℃; the other raw materials and preparation methods in this embodiment are the same as in Embodiment 1.

[0081] Example 4

[0082] This embodiment provides an indium oxide-based target with high mobility and low doping, and provides a method for its preparation.

[0083] The difference between this embodiment and Embodiment 1 is that in this embodiment, the X oxide is replaced with 0.5 parts of Y2O3, and the highest sintering temperature in the third stage of the sintering process is 1550℃; the other raw materials and preparation methods in this embodiment are the same as in Embodiment 1.

[0084] Example 5

[0085] This embodiment provides an indium oxide-based target with high mobility and low doping, and provides a method for its preparation.

[0086] The difference between this embodiment and embodiment 4 is that in this embodiment, Z oxide is replaced with an equal amount of MoO3, and the highest sintering temperature in the third stage of the sintering process is 1500℃; the other raw materials and preparation methods in this embodiment are the same as in embodiment 4.

[0087] Example 6

[0088] This embodiment provides an indium oxide-based target with high mobility and low doping, and provides a method for its preparation.

[0089] The difference between this embodiment and embodiment 4 is that in this embodiment, Z oxide is replaced with an equal amount of WO3, and the highest sintering temperature in the third stage of the sintering process is 1530℃; the other raw materials and preparation methods in this embodiment are the same as in embodiment 4.

[0090] Example 7

[0091] This embodiment provides an indium oxide-based target with high mobility and low doping, and provides a method for its preparation.

[0092] The raw materials of the indium oxide-based target in this embodiment, by mass parts, are: 99 parts In2O3, 0.2 parts Dy2O3 and 0.3 parts Y2O3, 0.2 parts B2O3, and 0.3 parts Ta2O5. The highest sintering temperature in the third stage of the sintering process is 1520℃. Other preparation methods are the same as in Example 1.

[0093] Example 8

[0094] This embodiment provides an indium oxide-based target with high mobility and low doping, and provides a method for its preparation.

[0095] The raw materials of the indium oxide-based target in this embodiment, by mass parts, are: 99 parts In2O3, 0.2 parts Dy2O3 and 0.3 parts Y2O3, 0.2 parts Bi2O3, and 0.3 parts Ta2O5. The highest sintering temperature in the third stage of the sintering process is 1550°C. Other preparation methods are the same as in Example 1.

[0096] Example 9

[0097] This embodiment provides an indium oxide-based target with high mobility and low doping, and provides a method for its preparation.

[0098] The raw materials of the indium oxide-based target in this embodiment, by mass parts, are: 99 parts In2O3, 0.1 parts X oxide: Dy2O3 and 0.3 parts Gd2O3, 0.3 parts Y oxide: B2O3, and 0.3 parts Z oxide: MoO3. The highest sintering temperature in the third stage of the sintering process is 1500℃; other preparation methods are the same as in Example 1.

[0099] Example 10

[0100] This embodiment provides an indium oxide-based target with high mobility and low doping, and provides a method for its preparation.

[0101] The raw materials of the indium oxide-based target in this embodiment, by mass parts, are: 99 parts In2O3, 0.3 parts X oxide: Gd2O3, 0.2 parts Y oxide: Bi2O3, and 0.5 parts Z oxide: MoO3. The highest sintering temperature in the third stage of the sintering process is 1480℃. Other preparation methods are the same as in Example 1.

[0102] Comparative Example 1

[0103] This comparative example provides an indium oxide-based target and its preparation method.

[0104] The raw materials of the indium oxide-based target in this comparative example, by mass parts, are: 99 parts In2O3 and 1 part SnO2;

[0105] All raw materials are oxide powders with a purity of 4N or higher; the median particle size range of In2O3 powder is 0.31μm < D50 < 0.45μm, and the median particle size range of SnO2 powder is 1.86μm < D50 < 3.15μm.

[0106] The specific steps of the preparation method of the indium oxide-based target in this comparative example are as follows:

[0107] 1) Ball milling, mixing, and granulation of powders:

[0108] Deionized water and dispersant polyvinylpyrrolidone (PVP) were added to SnO2 powder, and the mixture was ball-milled using a sand mill to obtain slurry 1. The ball-milling time was 6 hours, and the median particle size D50 of the mixed powder in slurry 1 was ≤0.20 μm.

[0109] In2O3 powder and deionized water were added to slurry 1, and slurry 2 was obtained by ball milling using a sand mill for 7 hours. The median particle size D50 of slurry 2 is ≤0.13μm.

[0110] Based on slurry 2, add 0.16 parts of binder (PVA) and 0.8 parts of plasticizer (PEG), mix well, and then spray granulate to obtain granulated powder.

[0111] 2) Forming of the unfinished blank:

[0112] Using a rotating target mold, granulated powder is injected into the mold, sealed, and placed in the hydraulic press chamber. The molding pressure is 185 MPa. After cold isostatic pressing, the powder is demolded to obtain the rotating target preform.

[0113] 3) Debinding and sintering:

[0114] After degreasing the target blank, it was sintered in a sintering furnace: the first stage sintering temperature was 70℃ and the holding time was 3h; the second stage sintering temperature was 940℃ and the holding time was 5.5h; the third stage sintering was carried out at the highest temperature of 1650℃, oxygen was introduced, and the holding time was 8.5h in an oxygen atmosphere; a dense indium oxide-based target was obtained.

[0115] This comparative example further provides a method for flaw detection and coating of the prepared indium oxide-based target material, the specific method of which is as follows:

[0116] Bonding flaw detection: The prepared rotating target coated with indium is bonded to the titanium tube and ultrasonic flaw detection is used, and no dark cracks are found.

[0117] TCO thin film deposition: On a cleaned glass substrate, a TCO thin film was deposited using magnetron sputtering at a power of 3kW and a film thickness of 90nm. The film was then annealed in an air atmosphere at 200°C for 30 minutes to obtain the TCO thin film, followed by performance testing.

[0118] Comparative Example 2

[0119] This comparative example provides an indium oxide-based target and its preparation method.

[0120] The raw materials for the indium oxide-based target in this comparative example, by mass parts, are 97 parts In2O3 and 3 parts SnO2. The highest sintering temperature in the third stage of the sintering process is 1600℃. Other preparation methods are the same as those in Comparative Example 1.

[0121] Comparative Example 3

[0122] This comparative example provides an indium oxide-based target and its preparation method.

[0123] The raw materials for the indium oxide-based target in this comparative example, by mass parts, are 90 parts In2O3 and 10 parts SnO2. The highest sintering temperature in the third stage of the sintering process is 1550℃. Other preparation methods are the same as those in Comparative Example 1.

[0124] Comparative Example 4

[0125] This comparative example provides an indium oxide-based target and its preparation method.

[0126] The raw materials used in this comparative example are the same as those in Example 3. The difference between this comparative example and Example 3 is that in the preparation method of this comparative example, in the ball milling, mixing and granulation steps of the powder, each raw material is mixed with deionized water and dispersant once and then ball milled in a sand mill to obtain a slurry. The ball milling time is 7 hours, the median particle size D50 of the slurry is ≤0.13μm, and the highest sintering temperature in the third stage of the sintering step is 1560℃. Other preparation steps are the same as those in Example 3.

[0127] Comparative Example 5

[0128] This comparative example provides an indium oxide-based target and its preparation method.

[0129] The raw materials for the indium oxide-based target in this comparative example, by mass parts, are: 99 parts In2O3, 0.16 parts of X oxides: Dy2O3, 0.48 parts of Y2O3, 0.16 parts of Gd2O3, and 0.2 parts of Z oxide MoO3. The highest sintering temperature in the third stage of the sintering process is 1620℃. Other preparation methods are the same as in Example 1.

[0130] Comparative Example 6

[0131] This comparative example provides an indium oxide-based target and its preparation method.

[0132] The raw materials for the indium oxide-based target in this comparative example, by mass parts, are: 99 parts In2O3, 0.53 parts Y oxide B2O3, 0.27 parts Bi2O3, and 0.2 parts Z oxide MoO3. The highest sintering temperature in the third stage of the sintering process is 1600℃. Other preparation methods are the same as in Example 1.

[0133] Comparative Example 7

[0134] This comparative example provides an indium oxide-based target and its preparation method.

[0135] The raw materials for the indium oxide-based target in this comparative example, by mass parts, are: 99.2 parts In2O3, 0.1 parts Dy2O3, 0.3 parts Y2O3 and 0.1 parts Gd2O3, 0.2 parts B2O3 and 0.1 parts Bi2O3, and the highest sintering temperature in the third stage of the sintering process is 1560℃; other preparation methods are the same as in Example 1.

[0136] The oxide raw material formulations for the various embodiments and comparative examples of this application are shown in Table 1:

[0137] Table 1. Oxide raw material ratios for each embodiment and comparative example.

[0138] Test example:

[0139] The density and average grain size of the targets prepared in each embodiment and comparative example were tested, and the carrier mobility, carrier concentration, and transmittance of the prepared TCO films were also tested. Specifically, the average grain size of the targets was tested using the cut-off method; the density of the targets was tested using the Archimedes displacement method; the carrier mobility and carrier concentration of the films were tested using a Hall effect spectrometer; and the transmittance of the films was tested using a UV-Vis-NIR spectrophotometer. The test results are shown in Table 2.

[0140] Table 2. Performance test data of the target materials and TCO films prepared in each embodiment and comparative example.

[0141] The test results above show that when using the method described in this application to prepare low-doped indium oxide-based targets, the highest sintering temperature range is 1480℃-1550℃. The density of the prepared indium oxide-based targets all reaches over 98.5%, and the average grain size of the targets ranges from 6.3μm to 8.5μm. Therefore, this application, through various doped oxides, achieves high density and low grain size targets at relatively low doping levels and sintering temperatures. Using the indium oxide-based targets prepared in this application, TCO thin films are obtained by magnetron sputtering on glass, with a carrier concentration reaching 1.58 × 10⁻⁶. 20 cm -3 -2.65×10 20 cm -3 The carrier mobility reached 66.8 cm⁻¹. 2 / V·S-85.1cm 2 With a transmittance of 89.6%-91.6% per V·s, the test results show that the TCO film prepared by the present application can achieve high transmittance and high carrier mobility while maintaining a low free carrier concentration, thus realizing the high performance of the TCO film. When used in HJT cells, it helps to improve their photoelectric conversion efficiency.

[0142] Comparative Examples 1 to 3 used conventional tin oxide doping. The tin oxide doping amount in Comparative Example 1 was the same as that in Examples 1 to 10. However, the sintering temperature of the target material prepared in Comparative Example 1 was as high as 1650°C, while the target density was only 95.3%, far lower than that of the target material prepared in this application. This indicates that the sintering aid effect of tin oxide is not as good as that of the composite oxide doping agent in this application. Furthermore, the carrier mobility and transmittance of the TCO film prepared from the target material of Comparative Example 1 were also far lower than those of the TCO films prepared in Examples 1 to 10. This may be due to the poor target density affecting the coating quality, or it may be that the doping of tin oxide in the indium oxide-based target material had a significantly adverse effect on the conductivity and transmittance of the indium oxide-based target material compared to the composite doping agent in this application. In Comparative Examples 2 and 3, the doping amount of tin oxide was increased, which led to a decrease in the sintering temperature and an increase in the density of the target material. However, the carrier mobility of the TCO film prepared by the target material decreased and the carrier concentration increased, resulting in a significant decrease in the performance of the TCO film. This is mainly because the increase in doping amount increased the carrier concentration and the content of impurity scattering centers, thereby reducing the carrier mobility.

[0143] Comparative Example 4 and Example 3 had the same raw material ratios, but the target sintering temperature of Comparative Example 4 was higher, and the properties of the TCO film prepared in Comparative Example 4 were worse than those of Example 3. This indicates that the preparation scheme of Comparative Example 4, which uses a single mixing method for each raw material, has lower mixing uniformity between the low-doped components and the indium oxide substrate than Example 3, which uses a two-mixing method. This results in a lower doping efficiency, which in turn leads to a lower carrier concentration and more impurities precipitated at the grain boundaries, thereby reducing the carrier mobility.

[0144] In Comparative Example 5, the absence of the Y oxide doping agent resulted in a significantly higher sintering temperature compared to Examples 1 to 10, reaching 1620°C, and the density of the prepared target material was also difficult to achieve a high level. In Comparative Example 6, the absence of the X oxide doping agent resulted in a higher sintering temperature compared to Examples 1 to 10, and the carrier mobility and light transmittance of the prepared TCO film were significantly reduced, leading to a deterioration in the performance of the TCO film.

[0145] In Comparative Example 7, the absence of Z oxide resulted in a significantly lower carrier concentration and carrier mobility in the prepared TCO film compared to Examples 1 to 10. This leads to a sharp decrease in the film's conductivity, making it difficult to meet the electrical performance requirements of HJT batteries for the TCO film. This is because, on the one hand, the incorporation of the high-valence oxide Z increases the carrier concentration; on the other hand, the smaller radius of the Z ion reduces lattice expansion caused by the incorporation of X oxide, thereby reducing lattice distortion and contributing to improved carrier mobility.

[0146] The embodiments of this application have been described in detail above. However, this application 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 protection scope of this application. Furthermore, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other.

Claims

1. An indium oxide-based target material, characterized in that, The raw materials used in the preparation include indium oxide, oxide X, oxide Y, and oxide Z; Among them, the oxide X includes at least one of Y2O3, Dy2O3 and Gd2O3; Y oxides include at least one of B2O3 and Bi2O3; Z oxides include at least one of Ta2O5, MoO3 and WO3.

2. The indium oxide-based target material according to claim 1, characterized in that, The raw materials for preparation include, by mass parts, 98.1-99.6 parts of indium oxide, 0.05-0.7 parts of oxide X, 0.05-0.7 parts of oxide Y and 0.05-0.6 parts of oxide Z.

3. The indium oxide-based target material according to claim 1, characterized in that, The raw materials used in the preparation also include dispersants, binders, plasticizers, and water.

4. The indium oxide-based target material according to claim 1, characterized in that, The oxide X includes Y2O3, Dy2O3 and Gd2O3.

5. A method for preparing an indium oxide-based target as described in any one of claims 1 to 4, characterized in that, Includes the following steps: S1: Mix the oxides of X, Y and Z, disperse and grind them, then add indium oxide and grind them again to obtain a mixed powder; S2: Cold isostatic pressing, degreasing, and sintering yield indium oxide-based target material.

6. The preparation method according to claim 5, characterized in that, In step S1, a dispersant and water are added before dispersion and grinding to obtain slurry 1; in step S1, indium oxide is added and ground to obtain slurry 2.

7. The preparation method according to claim 5, characterized in that, The sintering in step S2 includes three stages; The first stage sintering temperature is 600℃-800℃, and the holding time is 1h-5h. The second stage sintering temperature is 900℃-980℃, and the holding time is 3h-8h; The third stage involves sintering in an oxygen atmosphere at a temperature of 1450℃-1600℃ for 5-12 hours.

8. A TCO thin film, characterized in that, The TCO thin film is prepared using the indium oxide-based target material according to any one of claims 1 to 4; the carrier concentration of the TCO thin film is 1.2 × 10⁻⁶. 20 cm -3 -2.8×10 20 cm -3 Carrier mobility ≥ 60 cm 2 / V·S, transmittance ≥89% in the wavelength range of 400nm-1200nm.

9. A method for preparing a TCO thin film as described in claim 8, characterized in that, Includes the following steps: Using the target material described in any one of claims 1 to 4, a TCO thin film is obtained by magnetron sputtering with a deposition power of 1kW-10kW and a deposition thickness of 20nm-200nm.

10. The application of the target material as described in any one of claims 1 to 4, the preparation method as described in any one of claims 5 to 7, the TCO thin film as described in claim 8, or the preparation method as described in claim 9 in the field of HJT batteries.

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