High conductivity and high stability tin oxide-based target material and preparation method and application thereof

Abstract

The present invention discloses a tin oxide-based target material with high conductivity and high stability, a preparation method and an application thereof. The tin oxide-based target material provided by the present invention is doped with a metal oxide, the valence state of the metal element in the metal oxide is greater than +4, and the resistivity of the tin oxide-based target material is less than 7×10 ‑4 Ω·cm, relative density>98.5%. The above provided high conductivity and high stability tin oxide-based target material, the metal oxide doped into the target material is a high-valent metal oxide, and the valence of the metal element in the high-valent metal oxide is>+4, the metal ions replace the tin ions to provide more free electrons for the tin oxide target material, thereby improving the conductivity of the tin oxide-based target material, and the doped high-valent metal elements can inhibit the volatilization of tin oxide and improve the density of the tin oxide-based target material, and can enhance the stability of the system to make it more suitable for coating, batteries, transistors, display panels and other fields.

Description

Technical Field

[0001] The present invention relates to the technical field of target material preparation, and in particular to a tin oxide-based target material with high conductivity and high stability, and a preparation method and application thereof. Background Art

[0002] At present, In2O3-based TCO film (ITO) is the most widely used TCO material, but its scarce and expensive raw materials and the instability of ITO film during application limit the development of ITO materials. Therefore, the search for a low-cost, conductive and dense TCO material has received widespread attention. Tin dioxide is a low-cost, transparent conductive metal oxide with excellent photoelectric properties, and is one of the candidate materials to replace ITO. The successful application of the device is closely related to its stability. To obtain a uniform and stable quality TCO film, the target material for preparing the film must have high conductivity, high stability and high density. However, pure SnO2 has a high resistance, and under high-temperature sintering conditions, SnO2 sublimates and volatilizes in large quantities, resulting in a low density of the SnO2 target. Therefore, the need to develop a dense SnO2 target with high conductivity and high stability is expected in the art. Summary of the invention

[0003] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide a tin oxide-based target material with high conductivity and high stability and a preparation method and application thereof.

[0004] The present invention solves the technical problem by adopting the following technical solutions.

[0005] The present invention provides a tin oxide-based target material with high conductivity and high stability. The tin oxide-based target material is doped with a metal oxide, the valence state of the metal element in the metal oxide is greater than +4, and the resistivity of the tin oxide-based target material is less than 7×10 -4 Ω·cm, relative density>98.5%.

[0006] In some embodiments of the present invention, the valence state of the metal element in the metal oxide is +6.

[0007] In some embodiments of the present invention, the mass proportion of the metal oxide in the tin oxide-based target material is 1% to 3%.

[0008] In some embodiments of the present invention, the metal oxide is composed of molybdenum oxide and tungsten oxide, and the mass percentage of tungsten oxide in the metal oxide is 15% to 40%.

[0009] In some embodiments of the present invention, the purity of tin oxide is ≥99.99%, and the particle size is 20nm-100nm; the purity of molybdenum oxide and tungsten oxide is ≥99.99%, and the particle size is 1nm-20nm.

[0010] The present invention also provides a method for preparing the above-mentioned high-conductivity and high-stability tin oxide-based target material, comprising the following steps: placing a dispersant, a metal oxide and a tin oxide powder in water and stirring to obtain a mixed slurry, mixing the mixed slurry with a binder and granulating to obtain a mixed powder, pressing the mixed powder to obtain a green body, and then degreasing, sintering and heat-insulating the green body to obtain a high-conductivity and high-stability tin oxide-based target material.

[0011] In some embodiments of the present invention, the valence state of the metal element in the metal oxide is > +4;

[0012] Preferably, the valence state of the metal element in the metal oxide is +6;

[0013] Preferably, the mass proportion of the metal oxide in the tin oxide-based target material is 1% to 3%;

[0014] Preferably, the metal oxide consists of molybdenum oxide and tungsten oxide, and the mass proportion of tungsten oxide in the metal oxide is 15% to 40%.

[0015] In some embodiments of the present invention, the preparation of the mixed powder comprises the following steps: placing a dispersant, a metal oxide and a tin oxide powder in water and stirring them uniformly to obtain a mixed slurry; then sand-milling the mixed slurry, mixing it with a binder and spray granulating it to obtain a mixed powder;

[0016] Preferably, the dispersant in the mixed slurry is AG-330, the dispersant accounts for 0.3% to 0.9% of the total mass of the mixed slurry, the stirring speed is 1500rpm to 2500rpm, the time is 30 minutes to 60 minutes, and the solid content of the mixed slurry is 50% to 70%;

[0017] Preferably, the mixed slurry is sand-milled, mixed with a binder, stirred at 2500 rpm to 2800 rpm for 30 to 60 minutes, and then spray-granulated to obtain a mixed powder;

[0018] Preferably, during the sand milling process, the sand mill speed is 2000 rpm to 2500 rpm, the diaphragm pump speed is 500 rpm to 600 rpm, and the sand milling time is 4 hours to 8 hours;

[0019] Preferably, the binder is PVA, the ratio of the binder to the total mass of the mixed slurry and the binder is 0.5% to 1%, and the air inlet temperature of the spray granulation is 200°C to 230°C.

[0020] In some embodiments of the present invention, the preparation of a tin oxide-based target material with high conductivity and high stability comprises the following steps: molding a mixed powder to obtain a molded blank; cold isostatically pressing the molded blank to obtain a green blank, and performing a three-stage degreasing, sintering, and heat preservation treatment on the green blank to obtain a tin oxide-based target material with high conductivity and high stability;

[0021] Preferably, the compression molding pressure is 1 MPa to 5 MPa, and the holding time is 60 seconds to 150 seconds; the cold isostatic pressing pressure is 230 MPa to 260 MPa, and the holding time is 25 minutes to 35 minutes;

[0022] Preferably, the three-stage debinding-sintering-insulation treatment is as follows: first, the temperature is kept at 700°C to 800°C for 12 to 18 hours, with a heating rate of 0.6°C / min to 1.2°C / min; then, the temperature is kept at 1150°C to 1350°C for 4 to 8 hours, with a heating rate of 2 to 5°C; then, the temperature is kept at 1400°C to 1550°C for 6 to 8 hours, with a heating rate of 5°C / min to 20°C / min, and the sintering atmosphere is air sintering.

[0023] The present invention also provides an application of the above-mentioned high-conductivity and high-stability tin oxide-based target material in coating, batteries, transistors, and display panels.

[0024] The present invention has the following beneficial effects:

[0025] The present invention provides a tin oxide-based target material with high conductivity and high stability, and a preparation method and application thereof. The tin oxide-based target material with high conductivity and high stability provided by the present invention adopts a high-valent metal element doping method to provide more free electrons for the tin oxide-based target material, thereby improving the conductivity of the tin oxide-based target material and inhibiting the volatilization of tin oxide to increase the density of the target material, and can enhance the stability of the system to make it more suitable for coating, batteries, transistors, display panels and other fields. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0027] A highly conductive and highly stable tin oxide-based target material and a preparation method and application thereof provided in an embodiment of the present invention are specifically described below.

[0028] In the first aspect, the embodiment of the present invention provides a tin oxide-based target material with high conductivity and high stability. The tin oxide-based target material is doped with a metal oxide, the valence state of the metal element in the metal oxide is greater than +4, and the resistivity of the tin oxide-based target material is less than 7×10-4 Ω·cm, relative density>98.5%.

[0029] The embodiment of the present invention provides a tin oxide-based target material with high conductivity and high stability. The tin oxide-based target material is provided with more free electrons by doping with high-valent metal elements, thereby improving the conductivity of the tin oxide-based target material. The doped high-valent metal elements not only improve the conductivity of the tin oxide-based target material, but also inhibit the volatilization of tin oxide and improve the density of the target material, and can enhance the stability of the system to make it more suitable for coating, batteries, transistors, display panels and other fields.

[0030] In some optional embodiments, the valence state of the metal element in the metal oxide is +6.

[0031] When the valence state of the metal element of the metal oxide doped in the tin oxide-based target is +6, it is incompatible with the +4 valence Sn. 4+ The valence states are very different. The +6-valent metal ions replacing the +4-valent tin ions can provide more free electrons for the tin oxide-based target, effectively improving the conductivity of the tin oxide-based target.

[0032] In some optional embodiments, the mass proportion of metal oxide in the tin oxide-based target is 1% to 3%. As the content of metal oxide doped in the tin oxide-based target increases, the excess Mo 6+ and W 6+ Cannot replace Sn 4+ Instead of forming a solid solution, it gathers at the grain boundary to form a scattering center, resulting in a reduction in the donor, which causes the conductivity of the tin oxide-based target to decrease. Therefore, it is more appropriate to control the mass proportion of metal oxides in the tin oxide-based target to 1% to 3%.

[0033] In some optional embodiments, the metal oxide consists of molybdenum oxide and tungsten oxide, and the mass percentage of tungsten oxide in the metal oxide is 15% to 40%.

[0034] Pure tin dioxide is non-conductive and difficult to sinter. After a small amount of doping is required, the conductivity and sintering properties can be greatly improved, and the applicability is also wider. However, the performance and application of tin oxide-based targets doped with Mo or W single elements still have great limitations. Binary doping can make up for the shortcomings caused by single element doping, thereby improving the performance of tin oxide-based targets. However, the inventors also found that when co-doping Mo and W, the doping ratio of Mo and W has an important influence on the conductivity of tin oxide-based targets. When the proportion of Mo element is too low, the sintering performance of tin oxide-based targets is poor, resulting in a decrease in the density of tin oxide-based targets; if the concentration of Mo element is too high, Mo atoms aggregate through Mo-O-Mo bonds, which will reduce the donor concentration, thereby reducing the conductivity of tin oxide-based targets. Therefore, the high-conductivity and high-stability tin oxide-based targets provided in the embodiments of the present invention are achieved by co-doping molybdenum oxide and tungsten oxide in the tin oxide-based targets, and strictly controlling the binary co-doping ratio of molybdenum and tungsten, and regulating the donor concentration to achieve the purpose of simultaneously improving the conductivity and density of the target.

[0035] In some optional embodiments, the purity of tin oxide is ≥99.99%, and the particle size is 20nm-100nm; the purity of molybdenum oxide and tungsten oxide is ≥99.99%, and the particle size is 1nm-20nm.

[0036] In the second aspect, an embodiment of the present invention provides a method for preparing the above-mentioned high-conductivity and high-stability tin oxide-based target material, comprising the following steps: placing a dispersant, a metal oxide and a tin oxide powder in water and stirring to obtain a mixed slurry, mixing the mixed slurry with a binder, and granulating to obtain a mixed powder, pressing the mixed powder to obtain a green body, and then degreasing, sintering and heat-insulating the green body to obtain a high-conductivity and high-stability tin oxide-based target material.

[0037] In some embodiments of the present invention, the valence state of the metal element in the metal oxide is > +4;

[0038] Preferably, the valence state of the metal element in the metal oxide is +6;

[0039] Preferably, the mass proportion of the metal oxide in the tin oxide-based target material is 1% to 3%;

[0040] Preferably, the metal oxide consists of molybdenum oxide and tungsten oxide, and the mass proportion of tungsten oxide in the metal oxide is 15% to 40%.

[0041] At present, SnO phase is commonly found in SnO2 powder used to prepare metal-doped tin oxide targets. Using untreated SnO2 powder to prepare targets will have a negative impact on the performance of metal-doped tin oxide targets. There is a method to deposit SnO2 thin film in an O2 atmosphere by PVD, but due to the characteristics of PVD, when SnO2 is deposited on the surface of the target made of untreated SnO2 powder, there is still a large amount of SnO phase. In the process of oxidizing SnO to SnO2 using oxidants such as H2O2, O2, and O3, the residual oxidant will reduce the purity of the target. How to improve the performance of the target, such as conductivity and density, on the basis of effectively improving the purity of the target is an urgent problem to be solved.

[0042] In order to solve the above problems existing in the prior art, the embodiment of the present invention provides a method for preparing the above-mentioned high-conductivity and high-stability tin oxide-based target material, wherein the raw materials used mainly include: SnO2 powder, metal oxide, binder and dispersant, wherein: the metal oxide is an oxide of a high-valent metal element, and in some embodiments, MoO3 and WO3 are preferably doped into the tin oxide-based target material as metal oxides, which has the following advantages: Mo in MoO3 and WO3 6+ With W 6+ Both are stable +6 valent ions, and +4 valent Sn 4+ The valence state is very different, Mo 6+ , W 6+ Replace Sn 4+ The formation of double donors can provide more free electrons and effectively improve the conductivity. At the same time, the boiling point of MoO3 is 1150℃, which is lower than the volatilization temperature of SnO2 (1200℃). During the sintering heating process, MoO3 decomposes before SnO2 and generates MoO2 and oxygen molecules. The oxygen formed by the decomposition of MoO3 can effectively inhibit the decomposition and volatilization of SnO2, and can also oxidize the trace SnO impurities in the original SnO2 powder into SnO2, thereby improving the sintering performance of tin oxide-based targets and improving the density and purity of tin oxide-based targets. In addition, MoO2, Mo generated after the decomposition of MoO3 4+ Replace Sn 4 + The original conductivity of tin oxide will not be reduced. It can be seen that the tin oxide-based target prepared by the present invention has the characteristics of high purity, high density and high conductivity.

[0043] In some optional embodiments, the preparation of the mixed powder comprises the following steps: placing a dispersant, a metal oxide and a tin oxide powder in water and stirring them uniformly to obtain a mixed slurry; then sand-milling the mixed slurry, mixing it with a binder and spray-granulating it to obtain a mixed powder;

[0044] Preferably, the dispersant in the mixed slurry is AG-330, the dispersant accounts for 0.3% to 0.9% of the total mass of the mixed slurry, the stirring speed is 1500rpm to 2500rpm, the time is 30 minutes to 60 minutes, and the solid content of the mixed slurry is 50% to 70%;

[0045] Preferably, the mixed slurry is sand-milled, mixed with a binder, stirred at 2500 rpm to 2800 rpm for 30 to 60 minutes, and then spray-granulated to obtain a mixed powder;

[0046] Preferably, during the sand milling process, the sand mill speed is 2000 rpm to 2500 rpm, the diaphragm pump speed is 500 rpm to 600 rpm, and the sand milling time is 4 hours to 8 hours;

[0047] Preferably, the binder is PVA, the ratio of the binder to the total mass of the mixed slurry and the binder is 0.5% to 1%, and the air inlet temperature of the spray granulation is 200°C to 230°C.

[0048] In some optional embodiments, the preparation of a tin oxide-based target material with high conductivity and high stability comprises the following steps: molding the mixed powder to obtain a molded blank; cold isostatically pressing the molded blank to obtain a green blank, and performing a three-stage degreasing, sintering, and heat preservation treatment on the green blank to obtain a tin oxide-based target material with high conductivity and high stability;

[0049] Preferably, the compression molding pressure is 1 MPa to 5 MPa, and the holding time is 60 seconds to 150 seconds; the cold isostatic pressing pressure is 230 MPa to 260 MPa, and the holding time is 25 minutes to 35 minutes;

[0050] Preferably, the three-stage debinding-sintering-insulation treatment is as follows: first, the temperature is kept at 700°C to 800°C for 12 to 18 hours, with a heating rate of 0.6°C / min to 1.2°C / min; then, the temperature is kept at 1150°C to 1350°C for 4 to 8 hours, with a heating rate of 2 to 5°C; then, the temperature is kept at 1400°C to 1550°C for 6 to 8 hours, with a heating rate of 5°C / min to 20°C / min, and the sintering atmosphere is air sintering.

[0051] The above high-conductivity and high-stability tin oxide-based targets adopt a three-stage degreasing, sintering, and heat preservation treatment method during the sintering stage. The first stage of degreasing treatment is mainly to sinter out the dispersants and binders temporarily mixed in during the preparation process, so that there is basically no dispersant and binder in the finished tin oxide-based target, thereby improving the purity of the tin oxide-based target. The second stage of sintering treatment promotes the growth of tin dioxide grains, improves the density and grain size of the crystals, and the third stage of heat preservation treatment further improves the integrity and uniformity of the crystals. The above three-stage degreasing, sintering, and heat preservation treatment control the heating rate and heat preservation time in stages, which simplifies the preparation process of tin oxide-based targets while not reducing the sintering performance of tin oxide-based targets.

[0052] In a third aspect, an embodiment of the present invention provides an application of the above-mentioned high-conductivity and high-stability tin oxide-based target material in coating, batteries, transistors, and display panels.

[0053] The successful application of the device is closely related to its stability. Since the embodiment of the present invention adopts the method of co-doping with high-valent metal elements to prepare the high-conductivity and high-stability tin oxide-based target material, it is similar to Sn 4+ Compared to Mo 6+ , W 6+ With more free electrons outside the nucleus, 2- The formed Mo~O bonds and W~O bonds have stronger polarity, thereby enhancing the resistance to lattice deformation and improving the stability of the crystal structure, making the tin oxide-based target better suitable for device applications.

[0054] The present invention will be further described below in conjunction with the embodiments.

[0055] Example 1

[0056] (1) Weigh molybdenum oxide and tungsten oxide powders and mix them as metal oxides for later use, wherein the tungsten oxide accounts for 20% of the total mass of the metal oxides; weigh tin oxide powder and mix them as metal oxides for later use, wherein the ratio of tin oxide to metal oxide is 98:2.

[0057] (2) Deionized water, dispersant, metal oxide, and tin oxide powder are added to a beaker in sequence and stirred and dispersed using a stirrer. The stirrer speed is 2500 rpm, and the stirring time is 60 minutes to obtain a mixed slurry with a solid content of 60%. The dispersant AG-330 accounts for 0.4% of the total mass of the mixed slurry.

[0058] (3) The mixed slurry in step (2) is pumped into a sand mill by a diaphragm pump for sand milling. The sand milling time is 6 hours. The speed of the sand mill is 2000 rpm and the speed of the diaphragm pump is 500 rpm to obtain a molybdenum-tungsten doped tin oxide slurry.

[0059] (4) Add a binder to the molybdenum-tungsten-doped tin oxide slurry obtained in step (3), wherein the binder PVA accounts for 1% of the total mass of the mixed slurry and the binder. After stirring and dispersing with a stirrer at a speed of 2800 rpm for 40 minutes, the slurry is pumped into a spray dryer with a peristaltic pump for spray granulation. The inlet air temperature of the spray dryer is 220° C. Powder is collected from the bottom of the tower to obtain a molybdenum-tungsten-doped tin oxide mixed powder.

[0060] (5) The molybdenum-tungsten-doped tin oxide mixed powder in step (4) is molded to obtain a molded blank; and the molded blank is cold isostatically pressed to obtain a cold isostatically pressed green body. The molding pressure is 3 MPa, and the holding time is 120 seconds; the cold isostatic pressing pressure is 250 MPa, and the holding time is 30 minutes.

[0061] (6) The cold isostatically pressed green blank in step (5) is subjected to degreasing, sintering and heat preservation treatment in an air atmosphere to obtain a molybdenum-tungsten co-doped tin oxide target. The atmosphere for the degreasing, sintering and heat preservation treatment is air. First, the temperature is kept at 700°C for 16 hours at a heating rate of 0.6°C / min; then, the temperature is kept at 1250°C for 6 hours at a heating rate of 3°C; and then, the temperature is kept at 1500°C for 6 hours at a heating rate of 5°C / min.

[0062] Example 2

[0063] (1) Weigh molybdenum oxide and tungsten oxide powders and mix them for use as metal oxides, wherein the tungsten oxide accounts for 30% of the total mass of the metal oxides; weigh tin oxide powder and mix them for use, wherein the ratio of tin oxide to metal oxide is 99:1.

[0064] (2) Deionized water, dispersant, metal oxide, and tin oxide powder are added to a beaker in sequence and stirred and dispersed using a stirrer. The stirrer speed is 2600 rpm and the stirring time is 60 minutes to obtain a mixed slurry with a solid content of 60%. The dispersant AG-330 accounts for 0.6% of the total mass of the mixed slurry.

[0065] (3) The mixed slurry in step (2) is pumped into a sand mill by a diaphragm pump for sand milling. The sand milling time is 5 hours, the sand mill speed is 2200 rpm, and the diaphragm pump speed is 500 rpm to obtain a molybdenum-tungsten doped tin oxide slurry.

[0066] (4) Add a binder to the molybdenum-tungsten-doped tin oxide slurry obtained in step (3), wherein the binder PVA accounts for 1% of the total mass of the mixed slurry and the binder. After stirring and dispersing with a stirrer at a speed of 2600 rpm for 30 minutes, the slurry is pumped into a spray dryer with a peristaltic pump for spray granulation. The inlet air temperature of the spray dryer is 220° C. Powder is collected from the bottom of the tower to obtain a molybdenum-tungsten-doped tin oxide mixed powder.

[0067] (5) The molybdenum-tungsten-doped tin oxide mixed powder in step (4) is molded to obtain a molded blank; and the molded blank is cold isostatically pressed to obtain a cold isostatically pressed green body. The molding pressure is 2 MPa, and the holding time is 120 seconds; the cold isostatic pressing pressure is 250 MPa, and the holding time is 30 minutes.

[0068] (6) The cold isostatically pressed green blank in step (5) is subjected to degreasing, sintering and heat preservation treatment in an air atmosphere to obtain a molybdenum-tungsten co-doped tin oxide target. The atmosphere for the degreasing, sintering and heat preservation treatment is air. First, the target is kept at 700°C for 16 hours at a heating rate of 0.6°C / min; then, the target is kept at 1050°C for 6 hours at a heating rate of 3°C; then, the target is kept at 1450°C for 6 hours at a heating rate of 5°C / min.

[0069] Example 3

[0070] (1) Weigh molybdenum oxide and tungsten oxide powders and mix them as metal oxides for later use, wherein the tungsten oxide accounts for 20% of the total mass of the metal oxides; weigh tin oxide powder and mix them as metal oxides for later use, wherein the ratio of tin oxide to metal oxide is 98:2.

[0071] (2) Deionized water, dispersant, metal oxide, and tin oxide powder are added to a beaker in sequence and stirred and dispersed using a stirrer. The stirrer speed is 2500 rpm, and the stirring time is 60 minutes to obtain a mixed slurry with a solid content of 50%. The dispersant AG-330 accounts for 0.5% of the total mass of the mixed slurry.

[0072] (3) The mixed slurry in step (2) is pumped into a sand mill by a diaphragm pump for sand milling. The sand milling time is 4 hours. The sand mill speed is 2400 rpm and the diaphragm pump speed is 600 rpm to obtain a molybdenum-tungsten doped tin oxide slurry.

[0073] (4) Add a binder to the molybdenum-tungsten-doped tin oxide slurry obtained in step (3), wherein the binder PVA accounts for 1% of the total mass of the mixed slurry and the binder. After stirring and dispersing with a stirrer at a speed of 2500 rpm for 30 minutes, the slurry is pumped into a spray dryer with a peristaltic pump for spray granulation. The inlet air temperature of the spray dryer is 220° C. Powder is collected from the bottom of the tower to obtain a molybdenum-tungsten-doped tin oxide mixed powder.

[0074] (5) The molybdenum-tungsten-doped tin oxide mixed powder in step (4) is molded to obtain a molded blank; and the molded blank is cold isostatically pressed to obtain a cold isostatically pressed green body. The molding pressure is 1 MPa, and the holding time is 120 seconds; the cold isostatic pressing pressure is 250 MPa, and the holding time is 30 minutes.

[0075] (6) The cold isostatically pressed green blank in step (5) is subjected to degreasing, sintering and heat preservation treatment in an air atmosphere to obtain a molybdenum-tungsten co-doped tin oxide target. The atmosphere for the degreasing, sintering and heat preservation treatment is air. First, the temperature is kept at 700°C for 16 hours at a heating rate of 0.6°C / min; then, the temperature is kept at 1250°C for 6 hours at a heating rate of 3°C; and then, the temperature is kept at 1500°C for 6 hours at a heating rate of 5°C / min.

[0076] Comparative Example 1

[0077] The difference from Example 1 is that molybdenum oxide and tungsten oxide are not doped.

[0078] Comparative Example 2

[0079] The difference from Example 1 is that no molybdenum oxide is doped, only tungsten oxide is doped, and the ratio of tin oxide to tungsten oxide is 98:2.

[0080] Comparative Example 3

[0081] The difference from Example 1 is that tungsten oxide is not doped, only molybdenum oxide is doped, and the ratio of tin oxide to molybdenum oxide is 98:2.

[0082] Comparative Example 4

[0083] The difference from Example 1 is that the proportion of metal oxide is increased, the mass ratio of tin oxide to metal oxide is 95:5, and the proportion of tungsten oxide to the total mass of metal oxide is 20%.

[0084] Comparative Example 5

[0085] The difference from Example 1 is that the proportion of metal oxide is reduced, the mass ratio of tin oxide to metal oxide is 99.5:0.5, and the proportion of tungsten oxide to the total mass of metal oxide is 20%.

[0086] Comparative Example 6

[0087] The difference from Example 1 is that the proportion of tungsten oxide in the metal oxide is reduced, and the proportion of tungsten oxide in the total mass of the metal oxide is 5%.

[0088] Comparative Example 7

[0089] The difference from Example 1 is that the proportion of tungsten oxide in the metal oxide is increased, and the proportion of tungsten oxide in the total mass of the metal oxide is 60%.

[0090] The relative density and resistivity of the tin oxide-based targets prepared in the above-mentioned embodiments and comparative examples are shown in Table 1.

[0091] Table 1 Relative density and resistivity test results of tin oxide-based targets

[0092]

[0093]

[0094] It can be seen from Table 1 above that the pure tin dioxide in Comparative Example 1 is non-conductive and difficult to sinter, and has a low relative density. In Comparative Examples 2 to 3, a single doping method is used, and the single element doping has limited improvement on the conductivity and density of the tin oxide-based target. The tungsten-molybdenum co-doping method used in Comparative Examples 4 to 5 improves the density and conductivity of the tin oxide-based target prepared in Comparative Examples 2 to 3, but compared with the embodiments, the purity and conductivity of the tin oxide-based target are still reduced when the metal oxide content is too high or too low. The tungsten-molybdenum co-doping method used in Comparative Examples 6 to 7 improves the density and conductivity of the tin oxide-based target prepared in Comparative Examples 2 to 3, but compared with the embodiments, the purity and conductivity of the tin oxide-based target are still reduced when the proportion of tungsten oxide in the metal oxide is too high or too low.

[0095] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high conductivity and high stability tin oxide-based target material, characterized in that: The tin oxide-based target material is doped with a metal oxide, the valence state of the metal element in the metal oxide is greater than +4, and the resistivity of the tin oxide-based target material is less than 7×10 -4 Ω·cm, relative density>98.5%.

2. The high-conductivity and high-stability tin oxide-based target material according to claim 1, characterized in that: The valence state of the metal element in the metal oxide is +6.

3. The high-conductivity and high-stability tin oxide-based target material according to claim 2, characterized in that: The metal oxide accounts for 1% to 3% by mass in the tin oxide-based target.

4. The high-conductivity and high-stability tin oxide-based target material according to claim 3, characterized in that: The metal oxide consists of molybdenum oxide and tungsten oxide, and the mass proportion of the tungsten oxide in the metal oxide is 15% to 40%.

5. The high-conductivity and high-stability tin oxide-based target material according to claim 4, characterized in that: The purity of the tin oxide is ≥99.99%, and the particle size is 20nm-100nm; the purity of the molybdenum oxide and tungsten oxide is ≥99.99%, and the particle size is 1nm-20nm.

6. A method for preparing a high-conductivity and high-stability tin oxide-based target material according to any one of claims 1 to 5, characterized in that: The method comprises the following steps: placing a dispersant, a metal oxide and tin oxide powder in water and stirring to obtain a mixed slurry; mixing the mixed slurry with a binder and granulating to obtain a mixed powder; pressing the mixed powder to obtain a green body; and degreasing, sintering and heat-insulating the green body to obtain a tin oxide-based target material with high conductivity and high stability.

7. The preparation method according to claim 6, characterized in that: The valence state of the metal element in the metal oxide is greater than +4; Preferably, the valence state of the metal element in the metal oxide is +6; Preferably, the mass proportion of the metal oxide in the tin oxide-based target material is 1% to 3%; Preferably, the metal oxide consists of molybdenum oxide and tungsten oxide, and the mass proportion of the tungsten oxide in the metal oxide is 15% to 40%.

8. The preparation method according to claim 6, characterized in that: The preparation of the mixed powder comprises the following steps: The dispersant, metal oxide and tin oxide powder are placed in water and stirred evenly to obtain a mixed slurry; the mixed slurry is sand-milled, mixed with a binder and spray-granulated to obtain a mixed powder; Preferably, the dispersant in the mixed slurry is AG-330, the dispersant accounts for 0.3% to 0.9% of the total mass of the mixed slurry, the stirring speed is 1500rpm to 2500rpm, the time is 30 minutes to 60 minutes, and the solid content of the mixed slurry is 50% to 70%; Preferably, the mixed slurry is sand-milled, mixed with a binder, stirred at 2500 rpm to 2800 rpm for 30 to 60 minutes, and then spray-granulated to obtain a mixed powder; Preferably, during the sand milling treatment, the sand mill speed is 2000 rpm to 2500 rpm, the diaphragm pump speed is 500 rpm to 600 rpm, and the sand milling time is 4 hours to 8 hours; Preferably, the binder is PVA, and the ratio of the binder to the total mass of the mixed slurry and the binder is 0.5% to 1%, and the inlet air temperature of the spray granulation is 200°C to 230°C.

9. The preparation method according to claim 6, characterized in that: The preparation of the high-conductivity and high-stability tin oxide-based target material comprises the following steps: molding the mixed powder to obtain a molded green blank; cold isostatically pressing the molded green blank to obtain a green blank, and performing a three-stage degreasing, sintering, and heat preservation treatment on the green blank to obtain a high-conductivity and high-stability tin oxide-based target material; Preferably, the compression molding pressure is 1MPa-5MPa, and the holding time is 60 seconds-150 seconds; the cold isostatic pressing pressure is 230MPa-260MPa, and the holding time is 25 minutes-35 minutes; Preferably, the three-stage debinding-sintering-insulation treatment is as follows: first, the temperature is kept at 700°C to 800°C for 12 to 18 hours, with a heating rate of 0.6°C / min to 1.2°C / min; then, the temperature is kept at 1150°C to 1350°C for 4 to 8 hours, with a heating rate of 2 to 5°C; then, the temperature is kept at 1400°C to 1550°C for 6 to 8 hours, with a heating rate of 5°C / min to 20°C / min, and the sintering atmosphere is air sintering.

10. Use of the high-conductivity and high-stability tin oxide-based target material according to any one of claims 1 to 5 in coating, batteries, transistors, and display panels.

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