A kind of IZrO transparent conductive film and its preparation method and application

Abstract

The present invention relates to the field of materials science and technology, and in particular to an IZrO transparent conductive film, a preparation method thereof, and applications thereof. The IZrO transparent conductive film of the present invention is prepared by first preparing an IZrO thin film by magnetron co-sputtering an indium oxide target and a doped zirconium oxide target, and then heat treating the IZrO thin film. The IZrO transparent conductive film has a smooth and uniform surface, excellent electrical conductivity, and excellent optical transmittance, with a transmittance of not less than 95.4% at 400-1000nm. When applied to photovoltaic cells, the cells have a good response in the 400nm to 1000nm band, and the cell performance remains stable after 1000h at 85°C and 85% relative humidity.

Description

Technical Field

[0001] The present invention relates to the field of material science and technology, and in particular to an IZrO transparent conductive film and a preparation method and application thereof. Background Art

[0002] Transparent conductive oxides (TCO), such as indium tin oxide (ITO), are widely used in photovoltaic cells, displays and other fields.

[0003] Patent document CN108585832A discloses a method for preparing an indium tin oxide target. The method described in this invention makes the process easy to control, reduces the sintering temperature, promotes densification, and improves the target's conductivity. The sintered target has a more uniform composition, low resistivity, and high relative density. Patent document CN114436642A discloses a method for preparing an indium tin oxide alloy target. This application prepares an indium tin oxide alloy target with uniform structure, fine grains, and high thermal shock resistance. This alloy target can be used as a rotary target for vacuum coating to produce high-resistance, anti-electromagnetic interference, anti-static, and wear-resistant high-quality thin films. This can increase the uniformity of the film layer and improve the utilization rate of the target.

[0004] Although the indium tin oxide targets obtained in the aforementioned patents all have high density and excellent electrical conductivity, their high cost and low near-infrared transmittance limit their application. Therefore, the development of a new transparent conductive material is urgent. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to propose a preparation method of an IZrO transparent conductive film and its application, so as to provide a conductive film with excellent conductive properties and high near-infrared transmittance for use in photovoltaic cells.

[0006] Based on the above objectives, the present invention provides a method for preparing an IZrO transparent conductive film. The preparation method is as follows:

[0007] (1) Indium oxide target and doped zirconium oxide target were prepared by magnetron co-sputtering to obtain IZrO thin film;

[0008] (2) heat-treating the IZrO film to obtain an IZrO transparent conductive film;

[0009] The preparation steps of the doped zirconia target in step (1) are as follows:

[0010] The zirconium oxide powder is acid-washed, filtered, and washed to obtain a surface-roughened zirconium oxide powder; the surface-roughened zirconium oxide powder is then mixed with silicon tetrachloride, stirred evenly, allowed to stand for 3-4 hours, filtered, and dried to obtain a doped zirconium oxide powder;

[0011] The doped zirconia powder is ball-milled and then cold isostatically pressed to obtain a green embryo, and finally the green embryo is sintered at a high temperature of 1400° C. to 1650° C. to obtain a doped zirconia target.

[0012] Preferably, the purity of the indium oxide target in step (1) is not less than 99.9%.

[0013] Preferably, the magnetron co-sputtering process in step (1) adopts a DC magnetron sputtering system, and sputtering is performed in a mixed atmosphere of oxygen and argon, wherein the sputtering power is 100-150W, the flow ratio of oxygen to argon is 1:10, and the vacuum degree is maintained at 1×10 -3 Torr, heating temperature 450-600℃.

[0014] Preferably, the heat treatment temperature in step (2) is 300-500° C. and the time is 4-6 hours.

[0015] Preferably, the acid washing adopts a dilute hydrochloric acid solution with a concentration of 5-8 mol / L.

[0016] Preferably, the ratio of the zirconium oxide powder to the dilute hydrochloric acid is 50 g:100 mL.

[0017] Preferably, the particle size of the zirconium oxide powder is 70-100 μm.

[0018] Preferably, the thickness of the film is 50 nm.

[0019] Furthermore, the present invention also provides an IZrO transparent conductive film, which is prepared by the above-mentioned method for preparing the IZrO transparent conductive film.

[0020] Furthermore, the present invention also provides an application of an IZrO transparent conductive film, wherein the IZrO transparent conductive film is applied to a photovoltaic cell.

[0021] Beneficial effects of the present invention: The present invention performs doping modification on zirconium oxide powder so that silicon is doped into the zirconium oxide powder, and increases the specific surface area of ​​the zirconium oxide powder through surface treatment, thereby increasing the amount of silicon attached to the surface. In the subsequent magnetron sputtering process, more silicon oxide can be generated in situ and evenly distributed on the film to form a uniform conductive network, thereby improving the conductive performance of the film and improving the light transmittance of the film.

[0022] The IZrO transparent conductive film obtained by the present invention has good response in the 400nm to 1000nm band when applied to photovoltaic cells, and the cell performance remains stable after 1000 hours at 85°C and 85% relative humidity. DETAILED DESCRIPTION

[0023] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to specific embodiments.

[0024] Example 1: A method for preparing an IZrO transparent conductive film, the specific preparation steps are as follows:

[0025] (1) 100 g of 70 μm zirconium oxide powder was placed in 200 ml of 5 mol dilute hydrochloric acid solution at 50° C. for 2 h, filtered, washed three times with anhydrous ethanol, and dried under vacuum at 30° C. for 18 h to obtain surface-roughened zirconium oxide powder;

[0026] (2) 100 g of surface-roughened zirconium oxide powder and 200 g of silicon tetrachloride were mixed, stirred evenly, allowed to stand for 3 h, filtered, and dried at 40° C. for 20 h to obtain doped zirconium oxide powder;

[0027] (3) 100 g of doped zirconia powder was ball-milled at 400 rpm for 4 h and then pressed at 100 MPa for 160 s to obtain a green embryo. The green embryo was then sintered at 1400 °C for 2 h to obtain a density of 5.2 g / cm 3 Doped zirconia target;

[0028] (4) The doped zirconium oxide target and the indium oxide target were magnetron co-sputtered to obtain a film with a thickness of 50 nm. The power of the magnetron sputtering was 100 W, the flow ratio of oxygen to argon was 1:10, and the vacuum was maintained at 1×10 -3 Torr, heating temperature 450℃;

[0029] (5) The film was heat treated at 300°C for 4 h to obtain an IZrO transparent conductive film.

[0030] Example 2: A method for preparing an IZrO transparent conductive film, the specific preparation steps are as follows:

[0031] (1) 150 g of 85 μm zirconium oxide powder was placed in 300 ml of 7 mol dilute hydrochloric acid solution, reacted at 75° C. for 2 h, filtered, washed three times with anhydrous ethanol, and dried under vacuum at 70° C. for 21 h to obtain surface-roughened zirconium oxide powder;

[0032] (2) 125 g of surface-roughened zirconium oxide powder and 250 g of silicon tetrachloride were mixed, stirred evenly, allowed to stand for 4 h, filtered, and dried at 45 ° C for 22 h to obtain doped zirconium oxide powder;

[0033] (3) 125 g of doped zirconia powder was ball milled at 550 rpm for 5 h, and then pressed at 125 MPa for 200 s to obtain a green embryo. The green embryo was then sintered at 1550 ° C for 3 h to obtain a density of 5.3 g / cm 3 Doped zirconia target;

[0034] (4) The doped zirconium oxide target and the indium oxide target were magnetron co-sputtered to obtain a film with a thickness of 50 nm. The power of the magnetron sputtering was 125 W, the flow ratio of oxygen to argon was 1:10, and the vacuum was maintained at 1×10 -3 Torr, heating temperature 550℃;

[0035] (5) The film was heat treated at 400 °C for 5 h to obtain an IZrO transparent conductive film.

[0036] Example 3: A method for preparing an IZrO transparent conductive film, the specific preparation steps are as follows:

[0037] (1) 200 g of 100 μm zirconium oxide powder was placed in 400 ml of 8 mol dilute hydrochloric acid solution at 100° C. for 3 h, filtered, washed three times with anhydrous ethanol, and dried under vacuum at 100° C. for 24 h to obtain surface-roughened zirconium oxide powder;

[0038] (2) 150 g of surface-roughened zirconium oxide powder and 300 g of silicon tetrachloride were mixed, stirred evenly, allowed to stand for 4 h, filtered, and dried at 50° C. for 24 h to obtain doped zirconium oxide powder;

[0039] (3) 150 g of doped zirconia powder was ball milled at 700 rpm for 6 h, and then pressed at 150 MPa for 240 s to obtain a green embryo. The green embryo was then sintered at 1650 ° C for 4 h to obtain a density of 5.4 g / cm 3 Doped zirconia target;

[0040] (4) The doped zirconium oxide target and the indium oxide target were magnetron co-sputtered to obtain a film with a thickness of 50 nm. The power of the magnetron sputtering was 150 W, the flow ratio of oxygen to argon was 1:10, and the vacuum was maintained at 1×10 -3 Torr, heating temperature 600℃;

[0041] (5) The film was heat treated at 500 °C for 6 h to obtain an IZrO transparent conductive film.

[0042] Comparative Example 1: A method for preparing an IZrO thin film, the specific preparation steps are as follows:

[0043] The difference from Example 2 is that the zirconium oxide powder is not surface treated. The remaining steps are the same as Example 2. The specific steps are as follows:

[0044] (1) 125 g of zirconium oxide powder and 250 g of silicon tetrachloride were mixed, stirred evenly, allowed to stand for 4 h, filtered, and dried at 45 ° C for 22 h to obtain doped zirconium oxide powder;

[0045] (2) 125 g of doped zirconia powder was ball milled at 550 rpm for 5 h, and then pressed at 125 MPa for 200 s to obtain a green embryo. The green embryo was then sintered at 1550 ° C for 3 h to obtain a density of 5.3 g / cm 3 Doped zirconia target;

[0046] (3) The doped zirconium oxide target and the indium oxide target were magnetron co-sputtered to obtain a film with a thickness of 50 nm. The power of the magnetron sputtering was 125 W, the flow ratio of oxygen to argon was 1:10, and the vacuum was maintained at 1×10 -3 Torr, heating temperature 550℃;

[0047] (4) The film was heat treated at 400°C for 5 h to obtain an IZrO transparent conductive film.

[0048] Comparative Example 2: A method for preparing an IZrO thin film, the specific preparation steps are as follows:

[0049] The difference from the embodiment is that silicon oxide powder is directly mixed with silicon dioxide powder and ball milled. The specific preparation steps are as follows:

[0050] (1) 150 g of 85 μm zirconium oxide powder was placed in 300 ml of 7 mol dilute hydrochloric acid solution, reacted at 75° C. for 2 h, filtered, washed three times with anhydrous ethanol, and dried under vacuum at 70° C. for 21 h to obtain surface-roughened zirconium oxide powder;

[0051] (2) 1 g of surface roughened zirconium oxide powder and 25 g of silicon dioxide powder were ball milled at 550 rpm for 5 h, and then pressed at 125 MPa for 200 s to obtain a green embryo. The green embryo was then sintered at 1550 ° C for 3 h to obtain a density of 5.3 g / cm 3 Doped zirconia target;

[0052] (3) The doped zirconium oxide target and the indium oxide target were magnetron co-sputtered to obtain a film with a thickness of 50 nm. The power of the magnetron sputtering was 125 W, the flow ratio of oxygen to argon was 1:10, and the vacuum was maintained at 1×10 -3 Torr, heating temperature 550℃;

[0053] (4) The film was heat treated at 400°C for 5 h to obtain an IZrO transparent conductive film.

[0054] Comparative Example 3: A method for preparing an IZrO thin film, the specific preparation steps are as follows:

[0055] (1) 100 g of zirconium oxide powder and 25 g of silicon dioxide powder were ball-milled at 550 rpm for 5 h, and then pressed at 125 MPa for 200 s to obtain a green embryo. The green embryo was then sintered at 1550 ° C for 3 h to obtain a density of 5.3 g / cm 3 Doped zirconia target;

[0056] (2) The doped zirconium oxide target and the indium oxide target were magnetron co-sputtered to obtain a film with a thickness of 50 nm. The power of the magnetron sputtering was 125 W, the flow ratio of oxygen to argon was 1:10, and the vacuum was maintained at 1×10 -3 Torr, heating temperature 550℃;

[0057] (3) The film was heat treated at 400°C for 5 h to obtain an IZrO transparent conductive film.

[0058] Performance Testing

[0059] The surface roughness of the film was observed by AFM, and the test results are shown in Table 1;

[0060] The conductivity and mobility of the film were tested according to the Hall effect, and the test results are shown in Table 1;

[0061] The optical transmittance of the film was measured using a UV-visible-near-infrared spectrophotometer at a test wavelength of 400-1000 nm. The test results are shown in Table 1.

[0062] Table 1 Performance test results

[0063]

[0064]

[0065] The sample obtained in Example 2 was used as the front electrode of an n-type silicon-based photovoltaic cell with a cell structure of n-Si / IZrO / Ag. The prepared cell sample was tested:

[0066] The IV curve test shows that the open circuit voltage of the battery is 0.6V and the short circuit current density is 35mA / cm 2 , the fill factor is 0.75 and the conversion efficiency reaches 16.5%;

[0067] The EQE curve test shows that the battery has a good response in the 400nm to 1000nm band;

[0068] Stability tests show that the battery performance remains stable after 1000 hours at 85°C and 85% relative humidity.

[0069] Data analysis: It can be seen from Examples 1-3 in Table 1 that the IZrO transparent conductive film of the present invention has a smooth and uniform surface and excellent conductive properties, with a minimum resistivity of 4×10 -5 Ω·cm, and the carrier concentration can reach 4.5×10 20 cm -3 , the migration rate can reach 28cm 2 / Vs, and most importantly, it has excellent optical transmittance, with a transmittance of no less than 95.4% at 400-1000nm.

[0070] It can be seen from Example 2 and Comparative Example 1 in Table 1 that the present invention increases the specific surface area of ​​the zirconium oxide powder by surface treatment of the zirconium oxide powder, thereby allowing more silicon elements to adhere to the surface. In the subsequent magnetron sputtering process, more silicon oxide can be generated in situ and evenly distributed on the film to form a uniform conductive network. In addition, silicon dioxide itself has excellent light transmittance, which can improve the light transmittance of the film.

[0071] It can be seen from Example 2 and Comparative Example 2 in Table 1 that the present invention can make silicon dioxide evenly distributed in the film through doping and then in situ generation, forming a coherent conductive network, so that the conductivity of the target material is further improved and the light transmittance of the film is improved to a certain extent.

[0072] It can be seen from Example 2 and Comparative Example 3 in Table 1 that the present invention improves the conductivity of the target material by surface treating the zirconium oxide powder and then performing doping modification. The conductivity of the thin film obtained by sputtering is better and the light transmittance of the thin film is better. When applied to photovoltaic cells, the cells have good response in the 400nm to 1000nm band, and the battery performance remains stable after 1000h at 85°C and 85% relative humidity.

[0073] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention is limited to these examples. Within the scope of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

Claims

1. A method for preparing an IZrO transparent conductive film, characterized in that: The preparation method is as follows: (1) Place 100-200 g of zirconium oxide powder with a particle size of 70-100 μm in 200-400 ml of a 5-8 mol dilute hydrochloric acid solution at 50-100° C. for 2-3 hours, filter, wash three times with anhydrous ethanol, and dry under vacuum at 30-100° C. for 18-24 hours to obtain a surface-roughened zirconium oxide powder; (2) Mix 100-150 g of surface-roughened zirconium oxide powder and 200-300 g of silicon tetrachloride, stir evenly, let stand for 3-4 hours, filter, and dry at 40-50° C. for 20-24 hours to obtain doped zirconium oxide powder; (3) 100-150g of doped zirconia powder was ball milled at 400-700rpm for 4-6h, and then pressed at 100-150MPa for 160-240s to obtain a green embryo. The green embryo was then sintered at 1400-1650℃ for 2-4h to obtain a density of 5.2-5.4g / cm 3 Doped zirconia target; (4) Magnetron co-sputtering of doped zirconium oxide target and indium oxide target to obtain a film with a thickness of 50 nm, wherein the power of magnetron sputtering is 100-150 W, the flow ratio of oxygen to argon is 1:10, and the vacuum degree is maintained at 1×10 -3 Torr, heating temperature 450-600℃; (5) The film is heat treated at 300-500°C for 4-6 hours to obtain an IZrO transparent conductive film.

2. An IZrO transparent conductive film, characterized in that: The IZrO transparent conductive film is prepared by the preparation method of the IZrO transparent conductive film according to claim 1.

3. An application of the IZrO transparent conductive film according to claim 2, characterized in that: Used in photovoltaic cells.

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