High mobility indium oxide-based target material, method for producing the same, and use thereof

Abstract

The application belongs to the technical field of target materials for photovoltaic cells, and specifically discloses a high-mobility indium oxide-based target material and a preparation method and application thereof. The preparation raw material of the indium oxide-based target material comprises indium oxide, X oxide, Y oxide and Z oxide; wherein the X oxide comprises at least one of Y2O3, Dy2O3 and Gd2O3; the Y oxide comprises at least one of B2O3 and Bi2O3; and the Z oxide comprises at least one of Ta2O5, MoO3 and WO3. The highest sintering temperature of the indium oxide-based target material is relatively low, and the density is relatively high. The application realizes obtaining the indium oxide-based target material with high density and relatively low grain size at a relatively low doping amount and sintering temperature. The TCO thin film obtained by using the indium oxide-based target material for coating has high light transmittance and high carrier mobility, and can be used for HJT cells to improve photoelectric conversion efficiency.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of target materials for photovoltaic cells, in particular to a high-mobility indium oxide-based target material and a preparation method and application thereof. BACKGROUND

[0002] A silicon heterojunction solar cell (HJT cell) has high theoretical efficiency, a simple preparation process and a large cost reduction space, is a research hotspot in the field of solar cells at present and one of the solar cells for large-scale industrialization. A transparent conductive oxide (TCO film) has excellent conductivity and high light transmittance and is a core material of the HJT cell and an important guarantee for high photoelectric conversion efficiency.

[0003] At present, the TCO film for the HJT cell is mainly prepared by magnetron sputtering film coating of an In2O3-based target material. The content of In2O3 in the target material is mostly 90-99 wt%, and different photoelectric properties of the TCO film are obtained by regulating the type and content of the doped elements. With the development of the HJT cell industry, higher technical indexes of the carrier mobility and light transmittance of the TCO film are proposed to enable the HJT cell to have higher conversion efficiency. The carrier mobility of the TCO film prepared from a pure In2O3 target material can reach 150 cm 2 / V·S, which is much higher than that of the currently commercially available TCO film. However, the high sintering temperature (higher than 1800 DEG C) of the In2O3 target material due to the high melting point (2000 DEG C) of In2O3 greatly increases the energy consumption, production cost and equipment requirement. SnO2 is usually doped in the traditional In2O3-based target material to reduce the sintering temperature and increase the carrier concentration, but the effect of SnO2 is general, and a higher doping amount is needed to achieve a better effect. However, in the TCO film, the mobility is affected by the scattering between the electrons and the doped ions, and the increase of the doping amount increases the scattering in the carrier movement process, significantly reduces the carrier mobility of the TCO film and has an adverse effect on the light transmittance. At present, there is still a lack of a low-doped In2O3-based target material technology scheme with high carrier mobility and high light transmittance and capable of being sintered densely at a lower temperature (less than or equal to 1600 DEG C).

[0004] Therefore, it is urgent to develop an In2O3-based target material with high mobility, high light transmittance and low doping and capable of being sintered densely at a lower temperature, to solve the problem of uniform and efficient incorporation of the low-doped oxide in the matrix and to further improve the performance of the TCO film and the HJT cell and expand the application range and application prospect of the TCO film. SUMMARY

[0005] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides an indium oxide-based target material. The indium oxide-based target material of the present application has a lower sintering temperature and a higher density. The present application achieves a high-density target material with a lower grain size at a lower doping amount and sintering temperature by doping multiple oxides. The TCO thin film obtained by using the indium oxide-based target material for coating has high light transmittance and high carrier mobility, thereby improving the performance of the TCO thin film and further improving the photoelectric conversion efficiency of the HJT battery.

[0006] The present application also provides a preparation method of the indium oxide-based target material.

[0007] The present application also provides a TCO thin film.

[0008] The present application also provides a preparation method of the TCO thin film.

[0009] The present application also provides an application of the indium oxide-based target material.

[0010] In a first aspect of the present application, an indium oxide-based target material is provided, and the preparation raw materials include indium oxide, X oxide, Y oxide and Z oxide.

[0011] The X oxide includes at least one of Y2O3, Dy2O3 and Gd2O3.

[0012] The Y oxide includes at least one of B2O3 and Bi2O3.

[0013] The Z oxide includes at least one of Ta2O5, MoO3 and WO3.

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

[0015] The highest sintering temperature of the indium oxide-based target material of the present application does not exceed 1600 DEG C, which can reduce energy consumption, production cost and requirements for equipment, and is more suitable for large-scale industrial production. The density of the indium oxide-based target material prepared by the present application reaches 98.5% or more, and the average grain size of the target material ranges from 6.3 to 8.5 microns. The present application obtains a high-density target material with a lower grain size by doping multiple oxide additives. The TCO thin film obtained by using the indium oxide-based target material prepared by the present application has excellent performance, maintains a relatively low carrier concentration, and has a high carrier mobility of 60 cm 2 / V·S or more, and a light transmittance of 89% or more between wavelengths of 400 to 1200 nm, which can be used to further improve the photoelectric conversion efficiency of the HJT battery.

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

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

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

[0019] The present invention 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 the mobility of charge carriers.

[0020] Specifically, oxide X has higher doping activity. When it is incorporated into indium oxide, it causes lattice distortion, increases defects, and increases the cell volume. This makes it easier for the 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. They have opposite effects on the cell volume, resulting in a smaller overall change in the cell volume. The combined effect of the two makes the cell volume strain after doping smaller, 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+ The significant difference in radii results in low efficiency for high-valence ions when incorporated alone. Therefore, this invention 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 differences3+ (0.104nm), Dy 3+ (0.105nm), Gd 3+ (0.108nm) co-doped, improve the doping efficiency and the crystal stability, improve the target quality, and further improve the mobility and the light transmittance of the TCO film prepared from the target.

[0022] It is also found that the comprehensive performance of the target and the TCO film prepared from the target is the best when the three X oxides Y2O3, Dy2O3 and Gd2O3 are doped, and the performance data is better, and the reasonable proportion of the three X oxides achieves a relatively more optimal technical effect, which may be related to the special distribution of the outer electron of the rare earth ion nucleus.

[0023] In addition, the X oxide doping aid used in the application can also be used as a solid-phase sintering aid to reduce the sintering temperature by reducing the sintering activation energy, which promotes mass transfer, densification and improves doping efficiency by destroying the stability of the crystal structure of the indium oxide matrix material and generating lattice distortion or defects.

[0024] The Y oxide doping aid used in the application is used as a liquid-phase sintering aid, which forms a liquid phase with the indium oxide matrix material at a lower temperature, and the purpose of sintering densification at a lower temperature is achieved through the flow filling of the liquid phase and the “dissolution-precipitation” effect. The two sintering aids are used in the application to achieve the technical effects of optimally reducing the highest sintering temperature and promoting the densification of the target.

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

[0026] According to some embodiments of the application, the median particle size of the indium oxide powder ranges from 0.31 μm < D 50 < 0.45 μm, the median particle size of the X oxide powder ranges from 1.26 μm < D 50 < 1.75 μm, the median particle size of the Y oxide powder ranges from 2.15 μm < D 50 < 3.36 μm, and the median particle size of the Z oxide powder ranges from 1.86 μm < D 50 < 3.15 μm.

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

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

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

[0030] According to some embodiments of the present application, the preparation raw materials further include a dispersant, a binder, a plasticizer, and water.

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

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

[0033] The present application helps to improve the uniformity of the mixing of the oxide dopant and the indium oxide matrix in the preparation process of the indium oxide-based target by using a dispersant, thereby helping to improve the doping activity.

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

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

[0036] In a second aspect, the present application provides a preparation method of the indium oxide-based target according to the first aspect of the present application, including the following steps:

[0037] S1, mixing X, Y, and Z oxides, dispersing and grinding, then adding indium oxide and grinding, and granulating to obtain a mixed powder;

[0038] S2, cold isostatic pressing, debinding, and sintering to obtain the indium oxide-based target.

[0039] According to some embodiments of the present application, the step S1 adds a dispersant and water before dispersing and grinding to obtain slurry 1; and the step S1 adds indium oxide grinding to obtain slurry 2.

[0040] According to some embodiments of the present application, the median particle size of the slurry 1 is controlled to be D 50 ≤0.2 μm.

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

[0042] The present application improves the doping uniformity and efficiency of the doped oxide additive by a two-step mixing scheme. In combination with the improvement of the traditional process, the low content of doped oxides X, Y and Z are mixed and ball milled to obtain slurry 1, and the powder particle size is controlled to be less than that of indium oxide powder by grinding. Then, the doped oxide powder is mixed with the indium oxide powder to make the mixing more sufficient, achieve better auxiliary burning effect, and the target element distribution is more uniform, which can effectively improve the doping activity of the doped oxide, so that the thin film prepared by magnetron sputtering has better uniformity and performance. The present application further improves the performance of more than 10% of the target material and TCO thin film by improving the preparation process.

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

[0044] According to some embodiments of the present application, the sintering of step S2 includes three stages.

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

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

[0047] The third stage is sintered in an oxygen atmosphere, the sintering temperature is 1450-1600℃, and the holding time is 5-12h.

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

[0049] In a third aspect, the present application provides a TCO thin film prepared by using the indium oxide-based target material of the first aspect of the present application, the carrier concentration of the TCO thin film is 1.2×10 20 -2.8×10 20 cm -3 -1, the mobility is ≥60 cm 2 / V·S, and the light transmittance between wavelengths of 400-1200nm is ≥89%.

[0050] According to some embodiments of the present application, the carrier concentration of the TCO thin film is 1.58×10 20 -2.65×10 20 cm -3 -1, the mobility is ≥66.8 cm 2 / V·S, and the light transmittance between wavelengths of 400-1200nm is ≥89.6%.

[0051] In a fourth aspect, the present application provides a method for preparing the TCO film according to the third aspect of the present application, comprising the following steps:

[0052] The target material according to the first aspect of the present application is used to perform film plating by a magnetron sputtering method, the film plating power is 1-10 kW, and the film plating thickness is 20-200 nm, so as to obtain the TCO film.

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

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

[0055] In a fifth aspect, the present application provides an application of the target material according to the first aspect of the present application, or the preparation method according to the second aspect of the present application, or the TCO film according to the third aspect of the present application, or the preparation method according to the fourth aspect of the present application in the field of HJT cells.

[0056] Other features and advantages of the present application will be illustrated in the following description, and some will become apparent from the description, or will be understood by those skilled in the art through implementation of the present application. DETAILED DESCRIPTION

[0057] The concept and technical effects of the present application will be described in detail below in combination with embodiments, so as to fully understand the purposes, features and effects of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0058] Unless otherwise specified in the specific implementation, the implementation is carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are not marked with the manufacturer, which are conventional products that can be purchased on the market.

[0059] Example 1

[0060] The present embodiment provides a high-mobility and low-doped indium oxide-based target material and a preparation method thereof.

[0061] The raw materials of the indium oxide-based target material of the present embodiment are In2O399 parts, X oxide: Dy2O30.1 parts, Y2O30.3 parts and Gd2O30.1 parts, Y oxide: B2O30.2 parts and Bi2O30.1 parts, and Z oxide: Ta2O50.2 parts, in terms of mass fraction.

[0062] wherein each raw material is an oxide powder, and the purity is 4N or more; the median particle size of the In203powder is in the range of 0.31 μm < D 50 <0.45 μm, the median particle size of the X powder is in the range of 1.26 μm < D 50 <1.75 μm, the median particle size of the Y powder is 2.15 μm < D 50 <3.36 μm, the median particle size of the Z powder is 1.86 μm < D 50 <3.15 μm.

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

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

[0065] The X, Y and Z powders are mixed, 1.5 parts of deionized water and 0.005 parts of the dispersant polyvinylpyrrolidone (PVP) are added, and a sand mill is used for ball milling to obtain mixed slurry 1, the ball milling time is 6 h, and the median particle size D 50 ≤0.20 μm;

[0066] The In203powder, 148.5 parts of deionized water and 0.495 parts of PVP are added on the basis of the slurry 1. A sand mill is used for ball milling to obtain slurry 2, the ball milling time is 7 h, and the median particle size D 50 ≤0.13 μm;

[0067] The binder (PVA) 0.16 parts and the plasticizer (PEG) 0.8 parts are added on the basis of the slurry 2, and after mixing, the spray granulation is performed to obtain the granulated powder.

[0068] 2) Green compact forming:

[0069] The granulated powder is injected into the mold using a rotating target mold, and after packaging, it is placed into the chamber of a hydraulic machine, the forming pressure is 185 MPa, and after cold isostatic pressing, the rotating target green compact is obtained by demolding.

[0070] 3) Debinding and sintering:

[0071] After debinding the target green compact, sintering is performed in a sintering furnace: the first stage sintering temperature is 700°C, the holding time is 3 h, the second stage sintering temperature is 940°C, the holding time is 5.5 h, the third stage uses the highest temperature sintering, the sintering temperature is 1520°C, oxygen is introduced, the oxygen introduction speed is 42.5 L / min, the pressure is 2.35 kg / cm 2 , and the holding time in the oxygen atmosphere is 8.5 h; a dense indium oxide-based target material is obtained.

[0072] The embodiment further provides a method for detecting and coating the prepared indium oxide-based target material, and the specific method is as follows:

[0073] Binding detection: the prepared rotating target coated with indium is bound on a titanium tube, and ultrasonic detection is used, and there is no dark crack.

[0074] TCO film coating: a TCO film is deposited on the cleaned glass substrate by using a magnetron sputtering coating method, the coating power is 3 kW, the film thickness is 90 nm, then the TCO film is obtained by annealing in a muffle furnace at 200 ℃ in an air atmosphere for 30 min, and then performance test is carried out.

[0075] Embodiment 2

[0076] The embodiment provides a high-mobility and low-doped indium oxide-based target material and a preparation method thereof.

[0077] The embodiment and the embodiment 1 are different in that: in the embodiment, the Z oxide is replaced by an equal amount of MoO3, the highest sintering temperature in the third stage of the sintering step is 1480 ℃, and the other raw materials and the preparation method of the embodiment are the same as those of the embodiment 1.

[0078] Embodiment 3

[0079] The embodiment provides a high-mobility and low-doped indium oxide-based target material and a preparation method thereof.

[0080] The embodiment and the embodiment 1 are different in that: in the embodiment, the Z oxide is replaced by an equal amount of WO3, the highest sintering temperature in the third stage of the sintering step is 1500 ℃, and the other raw materials and the preparation method of the embodiment are the same as those of the embodiment 1.

[0081] Embodiment 4

[0082] The embodiment provides a high-mobility and low-doped indium oxide-based target material and a preparation method thereof.

[0083] The embodiment and the embodiment 1 are different in that: in the embodiment, the X oxide is replaced by 0.5 parts of Y2O3, the highest sintering temperature in the third stage of the sintering step is 1550 ℃, and the other raw materials and the preparation method of the embodiment are the same as those of the embodiment 1.

[0084] Embodiment 5

[0085] The embodiment provides a high-mobility and low-doped indium oxide-based target material and a preparation method thereof.

[0086] The embodiment and the embodiment 4 are different in that: in the embodiment, the Z oxide is replaced by an equal amount of MoO3, the highest sintering temperature in the third stage of the sintering step is 1500 ℃, and the other raw materials and the preparation method of the embodiment are the same as those of the embodiment 4.

[0087] Example 6

[0088] The present example provides a high mobility, low doped indium oxide based target material and a method for making the same.

[0089] The present example differs from example 4 in that the Z oxide is replaced with an equivalent amount of WO3 and the maximum sintering temperature in the third stage of the sintering step is 1530 °C. The other raw materials and method of making are the same as example 4.

[0090] Example 7

[0091] The present example provides a high mobility, low doped indium oxide based target material and a method for making the same.

[0092] The present example provides a high mobility, low doped indium oxide based target material and a method for making the same.

[0093] Example 8

[0094] The present example provides a high mobility, low doped indium oxide based target material and a method for making the same.

[0095] The present example provides a high mobility, low doped indium oxide based target material and a method for making the same.

[0096] Example 9

[0097] The present example provides a high mobility, low doped indium oxide based target material and a method for making the same.

[0098] The present example provides a high mobility, low doped indium oxide based target material and a method for making the same.

[0099] Example 10

[0100] The embodiment provides a high-mobility and low-doped indium oxide-based target material and a preparation method thereof.

[0101] The raw materials of the indium oxide-based target material of the embodiment are In2O399 parts, X oxide: Gd2O30.3 parts, Y oxide: Bi2O30.2 parts, and Z oxide: MoO30.5 parts in terms of mass fraction, and the highest sintering temperature in the third stage in the sintering step is 1480 DEG C; other preparation methods are the same as those in embodiment 1.

[0102] Comparative example 1

[0103] The comparative example provides an indium oxide-based target material and a preparation method thereof.

[0104] The raw materials of the indium oxide-based target material of the comparative example are In2O399 parts and SnO21 part in terms of mass fraction;

[0105] The raw materials are all oxide powders, and the purity is all above 4N; the median particle size of the In2O3 powder is in the range of 0.31 μm 50 ≤D 50 ≤3.15 μm.

[0106] The preparation method of the indium oxide-based target material of the comparative example comprises the following specific steps:

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

[0108] Deionized water and a dispersant polyvinylpyrrolidone (PVP) are added into the SnO2 powder, and a sand mill is used for ball milling to obtain slurry 1, the ball milling time is 6 h, and the median particle size D 50 ≤0.20 μm of the mixed powders in the slurry 1;

[0109] In2O3 powder and deionized water are added into the slurry 1, and a sand mill is used for ball milling to obtain slurry 2, the ball milling time is 7 h, and the median particle size D 50 ≤0.13 μm of the slurry 2;

[0110] The binder (PVA) 0.16 parts and the plasticizer (PEG) 0.8 parts are added into the slurry 2, and after mixing, the granulation powders are obtained through spray granulation.

[0111] 2) Green compact forming:

[0112] The granulation powders are injected into a rotary target mold, and after packaging, the rotary target green compact is obtained through cold isostatic pressing after the forming pressure of 185 MPa.

[0113] 3) Binder removal and sintering:

[0114] After the target blank is degreased, sintering is performed in a sintering furnace: the first stage sintering temperature is 70°C, the holding time is 3h, the second stage sintering temperature is 940°C, the holding time is 5.5h, the third stage uses the highest temperature sintering, the sintering temperature is 1650°C, oxygen is introduced, and the holding time in the oxygen atmosphere is 8.5h; a dense indium oxide-based target is obtained.

[0115] The present comparative example further provides a method for detecting defects and coating a prepared indium oxide-based target, and the specific method is as follows:

[0116] Binding defect detection: the prepared rotating target coated with indium is bound on a titanium tube, and ultrasonic detection is used, and there is no dark crack.

[0117] TCO film coating: a TCO film is deposited on a cleaned glass substrate using a magnetron sputtering coating method, the coating power is 3kW, the deposited film thickness is 90nm, then the TCO film is obtained by annealing in a muffle furnace at 200°C in an air atmosphere for 30min, and then performance testing is performed.

[0118] Comparative Example 2

[0119] The present comparative example provides an indium oxide-based target and a preparation method thereof.

[0120] The raw materials of the indium oxide-based target of the present comparative example are In2O397 parts and SnO23 parts by mass fraction, and the highest sintering temperature in the third stage of the sintering step is 1600°C; the other preparation methods are the same as those of Comparative Example 1.

[0121] Comparative Example 3

[0122] The present comparative example provides an indium oxide-based target and a preparation method thereof.

[0123] The raw materials of the indium oxide-based target of the present comparative example are In2O397 parts and SnO23 parts by mass fraction, and the highest sintering temperature in the third stage of the sintering step is 1600°C; the other preparation methods are the same as those of Comparative Example 1.

[0124] Comparative Example 4

[0125] The present comparative example provides an indium oxide-based target and a preparation method thereof.

[0126] The present comparative example has the same preparation raw materials as Example 3, and the difference between the present comparative example and Example 3 is that, in the preparation method of the present comparative example, the raw materials are mixed with deionized water and a dispersant once to obtain a slurry by sand mill ball milling, the ball milling time is 7h, the median particle size D50 of the slurry is 1.5μm, and the other preparation methods are the same as those of Example 3. 50≤0.13 μm, the maximum sintering temperature of the third stage in the sintering step was 1560 °C; and other preparation steps were the same as in Example 3.

[0127] Comparative Example 5

[0128] This comparative example provides an indium oxide-based target and a method for preparing the same.

[0129] The raw materials of the indium oxide-based target of this comparative example were, by mass fraction, In2O399 parts, X oxide: Dy2O30.16 parts, Y2O30.48 parts, Gd2O30.16 parts, Z oxide: MoO30.2 parts, the maximum sintering temperature of the third stage in the sintering step was 1620 °C; and other preparation methods were the same as in Example 1.

[0130] Comparative Example 6

[0131] This comparative example provides an indium oxide-based target and a method for preparing the same.

[0132] The raw materials of the indium oxide-based target of this comparative example were, by mass fraction, In2O399 parts, Y oxide: B2O30.53 parts, Bi2O30.27 parts, Z oxide: MoO30.2 parts, the maximum sintering temperature of the third stage in the sintering step was 1600 °C; and other preparation methods were the same as in Example 1.

[0133] Comparative Example 7

[0134] This comparative example provides an indium oxide-based target and a method for preparing the same.

[0135] The raw materials of the indium oxide-based target of this comparative example were, by mass fraction, In2O399.2 parts, X oxide: Dy2O30.1 parts, Y2O30.3 parts, and Gd2O30.1 parts, Y oxide: B2O30.2 parts, and Bi2O30.1 parts, the maximum sintering temperature of the third stage in the sintering step was 1560 °C; and other preparation methods were the same as in Example 1.

[0136] The oxide raw material ratios of the various examples and comparative examples of the present application are shown in Table 1:

[0137] Table 1 Oxide raw material ratios of various examples and comparative examples

[0138]

[0139] Test Example:

[0140] The density and average grain size of the target prepared in each embodiment and the comparative example were tested, and the carrier mobility, carrier concentration and light transmittance of the prepared TCO film were tested. Among them, the average grain size was measured by the intercept method; the target density was tested by the Archimedes drainage method; the sub-carrier mobility and concentration of the film were tested by using a Hall effect tester, and the light transmittance of the film was tested by using an ultraviolet-visible near-infrared spectrophotometer. The test results are shown in Table 2:

[0141] Table 2 Performance test data of target and TCO film prepared in each embodiment and the comparative example

[0142]

[0143] From the above test results, it can be seen that when the low-doped indium oxide-based target is prepared by using the scheme of the present application, the highest sintering temperature range of sintering is 1480-1550℃, and the density of the prepared indium oxide-based target reaches more than 98.5%, and the average grain size of the target ranges from 6.3 to 8.5μm. Therefore, by using multiple doped oxides, the present application realizes obtaining a high-density target with a lower grain size at a lower doping amount and sintering temperature. The TCO film is obtained by using the indium oxide-based target prepared by the scheme of the present application to perform magnetron sputtering on glass, the carrier concentration of the film reaches 1.58×10 20 -2.65×10 20 cm -3 , the carrier mobility reaches 66.8-85.1cm 2 / V·S, and the light transmittance is 89.6%-91.6%. The test results show that the TCO film prepared by the scheme of the present application can obtain high light transmittance and high carrier mobility while maintaining a low free carrier concentration, realizes high performance of the TCO film, and is used for HJT cells, which helps to improve the photoelectric conversion efficiency thereof.

[0144] Comparative Examples 1-3 use conventional tin oxide doping, wherein the tin oxide doping amount of Comparative Example 1 is the same as that of Examples 1-10, but the sintering temperature of the target material thereof is as high as 1650°C, and the target material density is only 95.3%, far lower than that of the target material prepared according to the scheme of the present application, indicating that the sintering effect of tin oxide is not as good as that of the composite oxide doping aid according to the scheme of the present application. In addition, the TCO film prepared from the target material of Comparative Example 1 has much lower mobility and light transmittance than Examples 1-10, which may be due to the poor quality of the film caused by the poor density of the target material, and may also be due to the fact that the tin oxide is doped in the indium oxide-based target material, which has a significant adverse effect on the conductivity and light transmittance of the indium oxide-based target material compared with the composite doping aid according to the scheme of the present application. In Comparative Examples 2 and 3, the amount of tin oxide doping is increased, which reduces the sintering temperature of the target material and increases the density of the target material, but the carrier mobility of the TCO film prepared from the target material decreases and the carrier concentration increases, resulting in a significant decrease in the performance of the TCO film, which is mainly due to the increase in the carrier concentration and the content of impurity scattering centers caused by the increase in the amount of doping, thereby reducing the mobility.

[0145] Comparative Example 4 has the same raw material ratio as Example 3, but the sintering temperature of the target material thereof is higher, and the performance of the TCO film prepared therefrom is also worse than that of Example 3, indicating that the one-time mixing scheme used for each raw material in the preparation scheme of Comparative Example 4 has lower mixing uniformity of the low-doping amount component and the indium oxide matrix than the two-time mixing scheme used in Example 3, resulting in lower doping efficiency, thereby resulting in lower carrier concentration, and more impurities precipitating at the grain boundaries, thereby reducing the mobility.

[0146] In Comparative Example 5, the Y oxide doping aid is omitted, resulting in a significantly higher sintering temperature of 1620°C compared with Examples 1-10, and the density of the target material prepared therefrom is also difficult to reach a high level. In Comparative Example 6, the X oxide doping aid is omitted, resulting in a higher sintering temperature compared with Examples 1-10, and the carrier mobility and light transmittance of the TCO film prepared therefrom are both significantly decreased, resulting in poor performance of the TCO film.

[0147] In Comparative Example 7, the Z oxide is omitted, and the carrier concentration of the TCO film prepared therefrom is much lower than that of Examples 1-10, and the mobility is also lower than that of Examples 1-10, which will cause a sharp decrease in the conductivity of the film, making it difficult to meet the electrical performance requirements of the TCO film for HJT cells. The reason is that on the one hand, the incorporation of the high-valence oxide Z can increase the carrier concentration, and on the other hand, the radius of Z ion is small, which can reduce the lattice expansion caused by the incorporation of X oxide, thereby reducing the lattice distortion and helping to improve the carrier mobility.

[0148] The above has described the embodiments of the present application in detail, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the spirit of the present application. In addition, the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

Claims

1. An indium oxide-based target material, characterized in that, The raw materials for preparation consist of 98.1-99.6 parts indium oxide, 0.05-0.7 parts X oxide, 0.05-0.7 parts Y oxide and 0.05-0.6 parts Z oxide by mass. Wherein, the oxide X is Y2O3, Dy2O3 and Gd2O3; The Y oxide is B2O3 and Bi2O3; The Z oxide is 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 used in the preparation also include dispersants, binders, plasticizers, and water.

3. The method for preparing the indium oxide-based target as described in claim 1 or 2, characterized in that, Includes the following steps: S1. Mix the X oxide, Y oxide and Z oxide, disperse and grind them, then add the indium oxide and grind them to obtain a mixed powder; S2. Cold isostatic pressing, degreasing, and sintering yield indium oxide-based target material.

4. The preparation method according to claim 3, 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.

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

6. A TCO thin film, characterized in that, The TCO thin film is prepared using the indium oxide-based target material as described in claim 1 or 2; the carrier concentration of the TCO thin film is 1.2 × 10⁻⁶. 20 ~2.8×10 20 cm -3 Mobility ≥ 60cm 2 / V·S, transmittance ≥89% between wavelengths of 400~1200nm.

7. The method for preparing the TCO thin film as described in claim 6, characterized in that, Includes the following steps: Using the indium oxide-based target material as described in claim 1 or 2, a TCO thin film is obtained by magnetron sputtering with a deposition power of 1~10kW and a deposition thickness of 20~200nm.

8. The application of the indium oxide-based target material as described in claim 1 or 2, the preparation method of the indium oxide-based target material as described in any one of claims 3 to 5, the TCO thin film as described in claim 6, or the preparation method of the TCO thin film as described in claim 7 in the field of HJT batteries.

Images