Indium titanium cerium niobium oxide ceramic target material, preparation method and application thereof, and transparent conductive oxide film

Abstract

The invention belongs to the technical field of photovoltaic target materials, and particularly relates to an indium titanium cerium niobium oxide ceramic target material, a preparation method and application thereof, and a transparent conductive oxide film. The indium titanium cerium niobium oxide ceramic target material comprises the following components: indium oxide, titanium oxide, cerium oxide and niobium oxide, the mass ratio of indium oxide to titanium oxide to cerium oxide to niobium oxide is 97-99: 1-0.3: 1-0.3: 1-0.2, the transparent conductive oxide film has high density, high purity and high strength, and the transparent conductive oxide film prepared from the transparent conductive oxide film has high carrier mobility, high conductivity and high light transmittance.

Description

Technical Field

[0001] The invention belongs to the technical field of photovoltaic target materials, and specifically relates to an indium titanium cerium niobium oxide ceramic target material and a preparation method and application thereof, and a transparent conductive oxide film. Background Art

[0002] With the development of the photovoltaic industry, especially the heterojunction photovoltaic cells occupying a certain position in the market, the traditional 90 / 10 mass ratio of indium tin oxide (ITO) target cannot meet the needs of heterojunction cells, because the traditional ITO target is only transparent in visible light, but not in the near-infrared region. At the same time, the carrier mobility of the traditional ITO target is only 30-40cm 2 V -1 S -1 .

[0003] By adding a small amount of oxides such as tungsten oxide, cerium oxide or zirconium oxide to indium oxide, a transparent conductive oxide target with high infrared transmittance and high mobility can be obtained. However, adding tungsten oxide, cerium oxide or zirconium oxide alone can only obtain ceramics with a density of 70-80%, and it is impossible to prepare ceramics with a density of more than 99%. At the same time, due to the low density of ceramic targets, their strength is also low, and magnetron sputtering coating cannot be carried out, and large-scale sputtering coating cannot be achieved.

[0004] In addition, in order to obtain higher film quality, photovoltaic ceramic targets generally use higher coating power to achieve dense crystal films. To ensure that the ceramic targets can be normally coated under high power, the ceramic targets need to have high strength. However, the current high-mobility ceramic targets generally have a strength of only 130-150MPa, which makes them easy to crack during the photovoltaic coating process. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide an indium titanium cerium niobium oxide ceramic target material and its preparation method and application, and a transparent conductive oxide film. The indium titanium cerium niobium oxide ceramic target material has high density and high strength, and the transparent conductive oxide film prepared therefrom has high carrier mobility, high conductivity and high transmittance.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides an indium titanium cerium niobium oxide ceramic target material, comprising the following components: indium oxide, titanium oxide, cerium oxide and niobium oxide;

[0008] The mass ratio of indium oxide, titanium oxide, cerium oxide and niobium oxide is 97-99:1-0.3:1-0.3:1-0.2.

[0009] Preferably, the relative density of the indium titanium cerium niobium oxide ceramic target material is ≥99%, and the bending strength is ≥190 MPa.

[0010] The present invention also provides a method for preparing the indium titanium cerium niobium oxide ceramic target material described in the above technical solution, comprising the following steps:

[0011] Mixing indium oxide powder, titanium oxide powder, cerium oxide powder, niobium oxide powder, a dispersant, a binder, a defoamer and water to prepare a slurry and ball-milling the mixture to obtain a ball-milled slurry;

[0012] Granulating the ball-milled slurry, and molding the obtained mixed powder to obtain a mixed body of indium oxide, titanium oxide, cerium oxide and niobium oxide;

[0013] The mixed green body of indium titanium cerium niobium oxide is degreased and sintered in sequence to obtain the indium titanium cerium niobium oxide ceramic target.

[0014] Preferably, the sintering temperature is 1100-1200° C., and the holding time is 3-5 hours.

[0015] Preferably, the sintering is microwave sintering; the microwave frequency of the microwave sintering is 2.45 GHz.

[0016] Preferably, the rotation speed of the ball mill is 1000-2500 rpm; and the time of the ball mill is 1-4 hours.

[0017] Preferably, the forming is cold isostatic pressing; the pressure of the cold isostatic pressing is 150-300 MPa, and the holding time is 5-30 min.

[0018] The present invention also provides the application of the oxide-doped indium oxide-based target material described in the above technical solution or the oxide-doped indium oxide-based target material prepared by the preparation method described in the above technical solution in the photovoltaic industry.

[0019] The present invention also provides a transparent conductive oxide film, which is obtained by sputtering and coating an indium titanium cerium niobium oxide ceramic target;

[0020] The indium titanium cerium niobium oxide ceramic target is the indium titanium cerium niobium oxide ceramic target described in the above technical solution or the indium titanium cerium niobium oxide ceramic target prepared by the preparation method described in the above technical solution.

[0021] Preferably, the sputtering coating is physical vapor deposition sputtering coating; the power of the sputtering coating is 120-200W.

[0022] The present invention provides an indium titanium cerium niobium oxide ceramic target material, comprising the following components: indium oxide, titanium oxide, cerium oxide and niobium oxide; the mass ratio of the indium oxide, titanium oxide, cerium oxide and niobium oxide is 97-99:1-0.3:1-0.3:1-0.2. In the present invention, titanium oxide can inhibit abnormal grain growth, refine grains, inhibit defect formation, and thus improve the strength of the target material. The ion radius of cerium is close to that of indium ions, and the lattice deformation of doped cerium is small. In addition, cerium oxide can reduce the oxygen vacancy content, thereby reducing the carrier concentration and improving the mobility. High mobility can reduce long-wave absorption, thereby improving light transmittance. Therefore, the indium titanium cerium niobium oxide ceramic target material provided by the present invention has high density, high purity and high strength, will not crack during the photovoltaic coating process, and the transparent conductive oxide film prepared therefrom has high carrier mobility, high conductivity and high light transmittance. Moreover, the indium titanium cerium niobium oxide ceramic target material provided by the present invention does not expand, deform or crack during the sintering process.

[0023] The present invention also provides a method for preparing the indium titanium cerium niobium oxide ceramic target. Niobium oxide can form a liquid phase during the sintering process and surround the indium oxide grain boundaries, greatly promoting particle rearrangement and mass transfer processes, thereby promoting sintering and reducing the temperature required for sintering.

[0024] Furthermore, the introduction of microwave sintering in the present invention can reduce the sintering temperature and sinter some products that cannot be sintered at high temperature into dense sintering, thereby achieving high density. While achieving high density, the strength is naturally improved, and microwave sintering can also significantly shorten the sintering time of large-size ceramic targets. DETAILED DESCRIPTION

[0025] The present invention provides an indium titanium cerium niobium oxide ceramic target material, comprising the following components:

[0026] Indium oxide, titanium oxide, cerium oxide, and niobium oxide;

[0027] The mass ratio of indium oxide, titanium oxide, cerium oxide and niobium oxide is 97-99:1-0.3:1-0.3:1-0.2.

[0028] Unless otherwise specified, the present invention has no special requirements on the sources of the raw materials used, and commercially available products known to those skilled in the art may be used.

[0029] The indium titanium cerium niobium oxide ceramic target provided by the present invention comprises the following components: indium oxide (In2O3), titanium oxide (TiO2), cerium oxide (CeO2) and niobium oxide (Nb2O5); the mass ratio of the indium oxide, titanium oxide, cerium oxide and niobium oxide is 97-99:1-0.3:1-0.3:1-0.2.

[0030] As an embodiment, the mass ratio of indium oxide, titanium oxide, cerium oxide and niobium oxide is 97-98:0.9-0.4:0.9-0.4:0.9-0.2, and in specific embodiments it is 97.3:0.9:0.9:0.9, 97.7:0.9:0.9:0.5, 98.1:0.9:0.5:0.5, 98.5:0.5:0.5:0.5 or 99:0.4:0.4:0.2.

[0031] As an embodiment, the density of the indium titanium cerium niobium oxide ceramic target is 7.095-7.112 g / m 3 ; Relative density ≥ 99%, in the specific embodiment, 99.23-99.46%; Flexural strength ≥ 190MPa, in the specific embodiment, 192-238MPa.

[0032] The present invention also provides a method for preparing the indium titanium cerium niobium oxide ceramic target material of the above technical solution, comprising the following steps:

[0033] Mixing indium oxide powder, titanium oxide powder, cerium oxide powder, niobium oxide powder, a dispersant, a binder, a defoamer and water to prepare a slurry and ball-milling the mixture to obtain a ball-milled slurry;

[0034] Granulating the ball-milled slurry, and molding the obtained mixed powder to obtain a mixed body of indium oxide, titanium oxide, cerium oxide and niobium oxide;

[0035] The mixed green body of indium titanium cerium niobium oxide is degreased and sintered in sequence to obtain the indium titanium cerium niobium oxide ceramic target.

[0036] The invention mixes indium oxide powder, titanium oxide powder, cerium oxide powder, niobium oxide powder, a dispersant, a binder, a defoamer and water to prepare a slurry, and then performs ball milling to obtain a ball-milled slurry.

[0037] As an implementation mode, the dispersant is triethanolamine; the mass of the dispersant is 0.5-1.5% of the total mass of the indium oxide, titanium oxide, cerium oxide and niobium oxide, and in a specific embodiment, it is 0.5-1%.

[0038] As an embodiment, the binder is one or more of polyvinyl alcohol (PVA), carboxymethyl cellulose, polyacrylamide and polyacrylic acid salt, and in a specific embodiment, it is polyvinyl alcohol (PVA); the mass of the binder is 1 to 2% of the total mass of the indium oxide, titanium oxide, cerium oxide and niobium oxide, and in a specific embodiment, it is 1.5 to 2%.

[0039] The dispersant in the present invention can make the raw material powder evenly dispersed in water when mixing to prepare the slurry, and the binder makes the mixed slurry have a certain viscosity, which is conducive to the subsequent molding.

[0040] As an embodiment, the defoaming agent is polyoxypropylene glycerol ether; the mass of the defoaming agent is 0.05-0.3% of the total mass of the indium oxide, titanium oxide, cerium oxide and niobium oxide, and in a specific embodiment, it is 0.1-0.2%.

[0041] As an implementation mode, the water is deionized water; the mass of the water is 35-45% of the total mass of the indium oxide, titanium oxide, cerium oxide and niobium oxide, and in a specific embodiment, it is 36-40%.

[0042] As an embodiment, the equipment used for ball milling is a sand mill; the ball milling medium used for ball milling is zirconium oxide beads; the particle size of the zirconium oxide beads is 0.2 to 0.6 mm, and in a specific embodiment, it is 0.3 to 0.5 mm; the rotation speed of the ball mill is 1000 to 2500 rpm, and in a specific embodiment, it is 1500 to 2400 rpm; the ball milling time is 1 to 4 hours, and in a specific embodiment, it is 1.5 to 3 hours; the particle size of the solid material in the slurry after ball milling is D 50 <0.3μm, D 90 <0.8μm, in the specific embodiment, D 50 ≤0.2μm, D 90 ≤0.5μm.

[0043] After obtaining the ball-milled slurry, the present invention granulates the ball-milled slurry, and shapes the obtained mixed powder to obtain a mixed body of indium oxide, titanium, cerium and niobium.

[0044] As an embodiment, the granulation is spray drying granulation; the temperature of the spray drying granulation is 220-245°C, and in a specific embodiment, it is 225-235°C.

[0045] As an embodiment, after the granulation, the method further comprises: screening the granules obtained by the granulation; the screening is performed using a 60-100 mesh sieve, and in a specific embodiment, 60-80 mesh.

[0046] As an embodiment, the forming is cold isostatic pressing; the pressure of the cold isostatic pressing is 150-300 MPa, and in a specific embodiment, it is 200-280 MPa, and the holding time is 5-30 min, and in a specific embodiment, it is 10-20 min.

[0047] After obtaining the mixed green body of indium titanium oxide, cerium and niobium, the present invention sequentially degreases and sinters the mixed green body of indium titanium oxide, cerium and niobium to obtain the indium titanium oxide, cerium and niobium ceramic target.

[0048] As an implementation mode, the degreasing temperature is 600-800°C, 700-800°C in a specific embodiment, the holding time is 2-3h, 2-2.5h in a specific embodiment; the heating rate to the degreasing temperature is 1-1.5°C / min, 1.2-1.5°C / min in a specific embodiment; the degreasing is carried out in air; the degreasing is microwave degreasing; the microwave frequency of the microwave degreasing is 2.45GHz.

[0049] As an implementation mode, the sintering temperature is 1100-1200°C, 1150-1200°C in a specific embodiment, the holding time is 3-5h, 4-5h in a specific embodiment; the heating rate to the sintering temperature is 1-1.5°C / min, 1.2-1.5°C / min in a specific embodiment; the sintering is microwave sintering; the microwave frequency of the microwave sintering is 2.45GHz; oxygen is introduced during the sintering process; the oxygen pressure during the sintering process is 0.05-0.1MPa, 0.07-0.1MPa in a specific embodiment.

[0050] The microwave sintering adopted in the present invention densifies the pressed mixed green body of indium titanium cerium niobium oxide by converting microwave energy into thermal energy.

[0051] The present invention increases the oxygen partial pressure of the sintering environment, can inhibit the decomposition of oxide raw materials at high temperatures, and thus improve the density of the target material.

[0052] The present invention also provides the application of the oxide-doped indium oxide-based target material described in the above technical solution or the oxide-doped indium oxide-based target material prepared by the preparation method described in the above technical solution in the photovoltaic industry.

[0053] The present invention has no special limitation on the application of the oxide-doped indium oxide-based target in the photovoltaic industry, and any application method well known in the art may be used.

[0054] The present invention also provides a transparent conductive oxide film, which is obtained by sputtering and coating an indium titanium cerium niobium oxide ceramic target;

[0055] The indium titanium cerium niobium oxide ceramic target is the indium titanium cerium niobium oxide ceramic target described in the above technical solution or the indium titanium cerium niobium oxide ceramic target prepared by the preparation method described in the above technical solution.

[0056] As an implementation mode, the sputtering coating is physical vapor deposition sputtering coating; the power of the sputtering coating is 120-200 W, and in a specific embodiment, it is 180 W; the sputtering gas used for the sputtering coating is argon, and the atmosphere used for the sputtering coating is a mixed gas of oxygen and hydrogen, wherein the volume ratio of oxygen to hydrogen is 1.5-2:1, and in a specific embodiment, it is 1.8:1; the thickness of the transparent conductive oxide film is 80-120 nm, and in a specific embodiment, it is 100-110 nm.

[0057] As an embodiment, the carrier mobility of the transparent conductive oxide film is ≥68cm 2 V -1 S -1 , 68 to 78 cm in the specific embodiment 2 V -1 S -1 The average light transmittance at 400-1200 nm is greater than 87%, and in the specific embodiment, it is 87.5-90.3%.

[0058] The present invention has no special limitation on the application method of the transparent conductive oxide film, and any application method known in the art may be used.

[0059] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention, but they should not be construed as limiting the protection scope of the present invention.

[0060] Example 1

[0061] Indium oxide powder, titanium oxide powder, cerium oxide powder and niobium oxide powder were weighed in a mass ratio of 97.3:0.9:0.9:0.9 and added to a ball mill. At the same time, based on the total mass of indium oxide, titanium oxide, cerium oxide and niobium oxide, 40wt% of deionized water, 0.5wt% of triethanolamine, 1.5wt% of PVA and 0.1wt% of polyoxypropylene glycerol ether were added. The mixed slurry was then ball milled in a sand mill at a speed of 2400rpm. The ball milling medium was zirconium oxide beads with a diameter of 0.3mm. The ball milling time was 1.5h. The particle size of the solid material in the slurry after ball milling was D 50 =0.2μm, D 90 =0.5μm; after ball milling, spray dry and granulate at 235°C, and pass through a 60-mesh sieve to obtain a mixed powder;

[0062] The mixed powder is subjected to cold isostatic pressing at 280 MPa for 30 minutes to obtain a mixed body of indium oxide, titanium oxide, cerium oxide and niobium oxide;

[0063] The mixed body of indium titanium cerium niobium oxide is placed in a microwave sintering furnace with a microwave frequency of 2.45 GHz, heated to 800°C in air at a rate of 1.5°C / min, kept warm for 2 hours for degreasing, and then oxygen is introduced with an oxygen pressure of 0.1 MPa, and continued to be heated to 1200°C at a rate of 1.5°C / min, kept warm for 5 hours for sintering, and cooled naturally to obtain an indium titanium cerium niobium oxide ceramic target.

[0064] Examples 2 to 7 and Comparative Examples 1 to 5

[0065] The difference between Examples 2 to 7 and Comparative Examples 1 to 5 and Example 1 is that the parameters of the preparation method, components and their contents are different, and the specific contents are shown in Table 1.

[0066] Table 1 Process parameters and component contents of each embodiment and comparative example

[0067]

[0068] Note: The high temperature sintering of Comparative Example 5 in Table 1 refers to sintering in a sintering furnace without microwaves.

[0069] Application Example 1

[0070] On the cleaned glass substrate, the indium titanium cerium niobium oxide ceramic target prepared in Example 1 was used to deposit the TCO film by physical vapor deposition sputtering coating. The coating power was 180 W, the sputtering gas was Ar, and the coating atmosphere was an H2 / O2 mixed gas with a volume ratio of oxygen and hydrogen of 1.8:1. The deposited film thickness was 100 nm to obtain a transparent conductive oxide film (TCO film).

[0071] Application Examples 2 to 7 and Comparative Application Examples 1 to 5

[0072] The difference from Application Example 1 is that the indium titanium cerium niobium oxide ceramic target prepared in Example 1 is replaced by the targets prepared in Examples 2 to 7 and Comparative Examples 1 to 5, respectively.

[0073] Performance Testing

[0074] 1. Processing and binding:

[0075] The target materials prepared in the above-mentioned embodiments and comparative examples were processed according to the dimensions in the drawings, bound to the titanium tube, and subjected to ultrasonic flaw inspection to find no dark cracks, and then a subsequent coating test was carried out.

[0076] 2. Coating test:

[0077] The target density was measured by the Archimedean drainage method.

[0078] The bending strength of the target material is measured by a universal mechanical testing machine.

[0079] On the cleaned glass substrate, the target materials prepared in the above embodiments and comparative examples were used to deposit TCO thin films by sputtering coating. The coating power was 180 W, the sputtering gas was Ar, the coating atmosphere was H2 / O2 mixed gas, the deposited film thickness was 100 mm, and the mobility of the film was tested by a Hall effect tester. The average transmittance of the film in the 400-1200 nm band was tested by an ultraviolet spectrophotometer.

[0080] The performance test results of the target materials prepared in each embodiment and comparative example, and the TCO films prepared therefrom are shown in Table 2.

[0081] Table 2 Performance test results of various embodiments and comparative examples

[0082]

[0083]

[0084] As can be seen from the above table, the indium titanium cerium niobium oxide ceramic target prepared by the present invention does not expand, deform, or crack during the sintering process, and has a high relative density and high bending strength. The TCO film prepared therefrom has a high carrier mobility and average light transmittance. At the same time, compared with the traditional high-temperature sintering technology, the use of high-temperature microwave sintering greatly reduces the sintering time. On the one hand, the maximum sintering temperature is reduced from 1500-1600°C to 1100-1200°C, and the insulation time at the highest temperature is also reduced from 35h to only 3-5h. On the other hand, the entire sintering time is also reduced from 240-300h of conventional sintering to only 30-50h to complete the sintering process.

[0085] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention rather than all the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. An indium titanium cerium niobium oxide ceramic target, characterized in that: The invention comprises the following components: indium oxide, titanium oxide, cerium oxide and niobium oxide; The mass ratio of indium oxide, titanium oxide, cerium oxide and niobium oxide is 97-99:1-0.3:1-0.3:1-0.

2.

2. The indium titanium cerium niobium oxide ceramic target according to claim 1, characterized in that: The relative density of the indium titanium cerium niobium oxide ceramic target material is ≥99%, and the bending strength is ≥190MPa.

3. The method for preparing the indium titanium cerium niobium oxide ceramic target according to claim 1 or 2, characterized in that: The following steps are involved: Mixing indium oxide powder, titanium oxide powder, cerium oxide powder, niobium oxide powder, a dispersant, a binder, a defoamer and water to prepare a slurry and ball-milling the mixture to obtain a ball-milled slurry; Granulating the ball-milled slurry, and molding the obtained mixed powder to obtain a mixed body of indium oxide, titanium oxide, cerium oxide and niobium oxide; The mixed green body of indium titanium cerium niobium oxide is degreased and sintered in sequence to obtain the indium titanium cerium niobium oxide ceramic target.

4. The preparation method according to claim 3, characterized in that: The sintering temperature is 1100-1200° C., and the heat preservation time is 3-5 hours.

5. The preparation method according to claim 3 or 4, characterized in that: The sintering is microwave sintering; the microwave frequency of the microwave sintering is 2.45 GHz.

6. The preparation method according to claim 3, characterized in that: The rotation speed of the ball mill is 1000-2500 rpm; the time of the ball mill is 1-4 hours.

7. The preparation method according to claim 3, characterized in that: The molding is cold isostatic pressing; the pressure of the cold isostatic pressing is 150-300 MPa, and the holding time is 5-30 minutes.

8. Use of the oxide-doped indium oxide-based target material according to claim 1 or 2 or the oxide-doped indium oxide-based target material prepared by the preparation method according to any one of claims 3 to 7 in the photovoltaic industry.

9. A transparent conductive oxide film, characterized in that: The indium titanium cerium niobium oxide ceramic target is prepared by sputtering coating; The indium titanium cerium niobium oxide ceramic target is the indium titanium cerium niobium oxide ceramic target according to claim 1 or 2 or the indium titanium cerium niobium oxide ceramic target prepared by the preparation method according to any one of claims 3 to 7.

10. The transparent conductive oxide thin film according to claim 9, characterized in that: The sputtering coating is physical vapor deposition sputtering coating; the power of the sputtering coating is 120-200W.

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