A tin oxide-based target material, a method for manufacturing the same, and an application thereof

Abstract

The application belongs to the technical field of target materials, and particularly discloses a tin oxide-based target material and a preparation method and application thereof.The preparation raw material of the tin oxide-based target material according to the application comprises, in terms of mass fraction, 91-95 parts of tin oxide, 1.5-3.5 parts of tantalum oxide, 1.5-3.5 parts of zinc oxide, 0.5-2 parts of tungsten oxide and 0.3-1.5 parts of gadolinium oxide, in addition to a binder and a plasticizer.The application further provides a preparation method and application of the tin oxide-based target material.The tin oxide-based target material provided by the application has high density and extremely low resistivity, with a density of greater than or equal to 6.5 g / m 3 and a resistivity of less than or equal to 1*10 ‑2 Ω*cm, and thus can be applied to DC power source magnetron sputtering coating.In addition, the tin oxide-based target material according to the application has the advantages of good light transmittance and low resistivity, can improve battery conversion efficiency, and can be applied to photovoltaic heterojunction cells and perovskite cells.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of target materials, in particular to a tin oxide-based target material and a preparation method and application thereof. BACKGROUND

[0002] Indium tin oxide (ITO) is considered as the most effective transparent conductive oxide (TCO) thin film manufacturing material due to its high light transmittance in the visible light range and very low resistance (usually 1-2*10 -4 Ω·cm). However, the natural reserves of indium are very low, the global supply is limited, and the competition for resource control is also fierce, so the supply of indium is limited and the cost is relatively high. In particular, the European Union completely relies on the import supply of indium, which means that the TCO manufacturing within the European Union and other low-carbon technologies that rely on indium are facing serious risks of indium supply. The natural reserves of tin are abundant and the price is relatively low, so it is often developed to replace ITO materials. The optical band gap of tin oxide (SnO2) is about 3.5-4.0 eV, and it shows degenerate n-type semiconductor characteristics when there are tin gaps or oxygen vacancies. Due to its good chemical stability, high visible light transmittance and relatively low resistivity, it is widely used in the fields of optoelectronic devices such as solar cells and gas sensors.

[0003] SnO2 is an n-type semiconductor, whose electrical conductivity mainly depends on the transfer of electrons between the valence band and the conduction band. In pure SnO2, the band gap is relatively wide, which means that electrons need a lot of energy to jump from the valence band to the conduction band, so the intrinsic electron concentration is low. In addition, the tetragonal lattice structure of SnO2 also affects its electrical conductivity. Oxygen vacancies and tin interstitials in its lattice form traps that capture free electrons, further reducing the mobility of electrons, thus reducing the electrical conductivity. Moreover, traditional pressureless sintering is difficult to densify pure SnO2 ceramics without additives, which is related to the sintering mechanism of pure SnO2 ceramics (surface diffusion at low temperature and evaporation-condensation at high temperature). The sintered body shows a porous, loose and low-strength structure. When pure SnO2 is used as an electron transport layer, there are many problems of Sn dangling bonds and oxygen vacancy defects, which lead to charge recombination and exacerbate the instability of the interface. Therefore, the development of SnO2-based targets, especially SnO2-based targets suitable for DC power magnetron sputtering coating, has been in the exploratory stage. DC power magnetron sputtering coating has the advantages of suppressing arc generation, eliminating film defects, improving sputtering deposition rate and reducing deposition temperature, etc., and has become one of the important means of industrialized coating. However, the conductivity of the target material is very strict for DC power magnetron sputtering coating. After applying a direct current bias and sputtering for a short time, the cations reaching the target surface cannot be discharged in time, causing accumulation of positive charges on the target surface, resulting in insufficient potential difference between the target surface and the plasma (sheath) to incubate cations to reach the target function, ultimately causing the plasma to extinguish.

[0004] The above analysis shows that there is a lot of room for improvement in SnO2 targets. Chinese patent CN116813329A optimizes the density and resistivity of SnO2 targets by modifying the doping of Ta2O5, but there is still room for improvement. Chinese patent CN114560692A discloses a method for preparing a zinc oxide-doped tin oxide target by hot-pressing sintering. The prepared target has high density, but the resistivity of the target material doped with pure zinc oxide is still high, which cannot be sputtered by DC power. Therefore, it is urgent to develop a new type of SnO2-based target and its preparation, which can be suitable for DC power magnetron sputtering coating, and help SnO2-based films to gradually realize industrialization. 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 a tin oxide-based target material, which has the advantages of high density and low resistance, is suitable for DC power magnetron sputtering coating, can also be applied to photovoltaic heterojunction cells and perovskite cells, has good light transmittance, low resistivity, improves the conversion efficiency of the cell, and has lower cost than ITO target material.

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

[0007] The present application also provides the application of the above-mentioned tin oxide-based target material.

[0008] In a first aspect of the present application, a tin oxide-based target material is provided, and the preparation raw materials include, by mass fraction: 91-95 parts of tin oxide, 1.5-3.5 parts of tantalum oxide, 1.5-3.5 parts of zinc oxide, 0.5-2 parts of tungsten oxide, and 0.3-1.5 parts of gadolinium oxide.

[0009] According to the specific embodiments of the present application, the tin oxide-based target material provided by the present application has at least the following beneficial effects: the tin oxide-based target material of the present application has high density and extremely low resistivity, so that it can be applied to DC power magnetron sputtering coating; in addition, the tin oxide-based target material of the present application also has the advantages of good light transmittance and low resistivity, which can improve the conversion efficiency of the cell and can be applied to photovoltaic heterojunction cells and perovskite cells.

[0010] Compared with ITO target material, the tin oxide-based target material has the advantages of abundant natural resources and lower cost, and the present application realizes the preparation of a tin oxide-based target material with high density and extremely low resistance by reasonably doping a certain amount of tantalum oxide, zinc oxide, tungsten oxide and gadolinium oxide in the target material with tin oxide as the base.

[0011] The doping of tantalum oxide is because the radius of Ta element is 0.064 nm, which is smaller than the radius of Sn element, so the Ta element can replace the position of Sn element, and form Sn (1 -x)Ta xThe solid solution of O2, and because the valence of Ta element is 5+, which is higher than the valence of Sn element 4+, therefore, the replacement of Ta element will introduce electron holes in SnO2, increase the carrier concentration, and thus improve the conductivity of SnO2; in addition, the replacement of Ta element will also affect the crystal structure of SnO2, so that the lattice constant changes, and with the increase of the doping amount of Ta element, the replacement of Ta element will make the crystal structure of SnO2 more compact and stable; the replacement of Ta element will also affect the sintering behavior and density of SnO2, and with the increase of the doping amount of Ta element, the sintering temperature of SnO2 will be reduced, and the density after sintering will also be improved, because the replacement of Ta element will promote the grain growth and grain boundary diffusion of SnO2, thus speeding up the sintering process and reducing the porosity.

[0012] Zinc oxide doping 2+ The radius of 0.074 nm is larger than that of Sn 4+ The radius of 0.071 nm, when Zn replaces Sn, will make its adjacent oxygen atom escape and form an oxygen vacancy, promote the development of SnO2 lattice, and produce a large number of electrons, greatly increasing the conductivity; at the same time, within a certain doping range, ZnO reacts with SnO2 at high temperature to form Zn2SnO4, filling the gap between the particles, greatly strengthening the sintering densification of the target material, realizing the sintering promotion of the tin oxide-based target material, and promoting the sintering densification. The present application also finds that too much ZnO doping will cause the target material to sinter and crack, and provides a suitable doping amount.

[0013] Tungsten oxide doping 6+ Sn 4+ , can enhance the electronic and optical properties of tin oxide; in addition, W 6+ , among the common doping elements, has the highest valence, can produce more free electrons; at the same time, the doping of W element also helps to produce more carriers and maintain the structural ability of tin oxide.

[0014] The 4f electrons of Gd ions doped in gadolinium oxide will form hybrid orbits with SnO2, thereby increasing the carrier concentration and enabling more electrons to transition to the conduction band; at the same time, after doping, the energy band structure of SnO2 is more matched with the perovskite layer of the solar cell, which may lead to higher charge transfer at the electron transport layer and perovskite interface, and less recombination at the interface; in addition, as a rare earth element, Gd also has strong light absorption, which will change the optical properties of SnO2 and affect its application in optoelectronic devices; although Gd doping can improve the conductivity of SnO2, the present application finds that high gadolinium oxide doping concentration may cause lattice distortion, affecting the stability and other physical properties of SnO2, therefore, the present application provides a suitable doping amount of gadolinium oxide.

[0015] In some embodiments of the present application, the preparation raw materials comprise, in parts by mass: 91.5-94.5 parts of tin oxide, 2-3 parts of tantalum oxide, 2-3 parts of zinc oxide, 1-1.5 parts of tungsten oxide, and 0.5-1 part of gadolinium oxide.

[0016] In some preferred embodiments of the present application, the preparation raw materials comprise, in parts by mass: 91.5-93 parts of tin oxide, 2.5-3 parts of tantalum oxide, 2.5-3 parts of zinc oxide, 1-1.5 parts of tungsten oxide, and 0.5-1 part of gadolinium oxide.

[0017] In some embodiments of the present application, the preparation raw materials further comprise a binder and a plasticizer.

[0018] In some preferred embodiments of the present application, the binder is in parts by mass of 0.4-2.5 parts, and the plasticizer is in parts by mass of 0.1-2 parts.

[0019] In some more preferred embodiments of the present application, the binder is in parts by mass of 0.5-2 parts, and the plasticizer is in parts by mass of 0.5-1.5 parts.

[0020] In some embodiments of the present application, a binder is added to improve the compactness and mechanical properties of the shaped piece, and the binder is polyvinyl alcohol (PVA) commonly used in the art, and other substances having similar effects can be used as the binder of the present application.

[0021] In some embodiments of the present application, a plasticizer is added to improve the plasticity of the blank, and the plasticizer is polyethylene glycol (PEG) commonly used in the art, and other substances having similar effects can be used as the plasticizer of the present application.

[0022] In some embodiments of the present application, the tin oxide, tantalum oxide, zinc oxide, tungsten oxide, and gadolinium oxide are all in the form of powder.

[0023] In some preferred embodiments of the present application, the specific surface area of the powder is independently 10-25 m 2 / g.

[0024] In some more preferred embodiments of the present application, the specific surface area of the powder is independently 15-20 m 2 / g.

[0025] In some preferred embodiments of the present application, the D50 of the tantalum oxide, zinc oxide, tungsten oxide, and gadolinium oxide powder is ≤2 μm, and the Dmax is ≤10 μm.

[0026] In some embodiments of the present application, the density of the tin oxide-based target material is ≥6.5 g / m3 .

[0027] In some preferred embodiments of the present application, the density of the tin oxide-based target is ≥ 6.55 g / m 3 .

[0028] In some more preferred embodiments of the present application, the density of the tin oxide-based target is 6.6-6.75 g / m 3 .

[0029] In some embodiments of the present application, the resistivity of the tin oxide-based target is ≤ 1 x 10 -2 Ω·cm.

[0030] In some preferred embodiments of the present application, the resistivity of the tin oxide-based target is ≤ 2 x 10 -3 Ω·cm.

[0031] In a second aspect of the present application, a method for preparing the tin oxide-based target according to the first aspect of the present application is provided, comprising the following steps:

[0032] S1, mixing oxide raw materials, ball milling, and spray drying;

[0033] S2, static pressure forming to obtain a green body;

[0034] S3, debinding, hot-pressing sintering, to obtain the tin oxide-based target.

[0035] In some embodiments of the present application, a binder and a plasticizer are added during the ball milling of step S1.

[0036] In some embodiments of the present application, the specific surface area of the mixed powder after the spray drying of step S1 is 5-25 m 2 / g.

[0037] In some preferred embodiments of the present application, the specific surface area of the mixed powder after the spray drying of step S1 is 10-20 m 2 / g.

[0038] In some embodiments of the present application, the loose bulk density of the mixed powder after the spray drying of step S1 is 1.1 g / cm 3 ~ 1.6 g / cm 3 .

[0039] In some preferred embodiments of the present application, the loose bulk density of the mixed powder after the spray drying of step S1 is 1.3 g / cm 3 ~ 1.5 g / cm 3 .

[0040] In some embodiments of the present application, the static pressure forming method of step S2 is cold isostatic pressing (CIP) at a pressure of 100-200 MPa.

[0041] In some embodiments of the present application, the debinding temperature of step S3 is 600-650℃, and the time is 2-3h.

[0042] In some preferred embodiments of the present application, the debinding conditions of step S3 are: heating to 600-650℃ under an oxygen atmosphere, and debinding for 2-3h. Debinding under an oxygen atmosphere can prevent the volatilization of tin oxide.

[0043] In some more preferred embodiments of the present application, the debinding conditions of step S3 are: heating to 600-650℃ at a heating rate of 1-3℃ / min under an oxygen atmosphere, and debinding for 2-3h.

[0044] In some embodiments of the present application, the hot-pressing sintering of step S3 comprises the following steps:

[0045] S31, heating to 600-650℃ and holding for 5-7h;

[0046] S32, heating to 950-1000℃ and holding for 3-4h;

[0047] S33, heating to 1350-1400℃ at a pressure of 25-35 MPa and holding for 2-3h.

[0048] In some preferred embodiments of the present application, the hot-pressing sintering of step S3 comprises the following steps:

[0049] S31, heating to 600-650℃ at a heating rate of 2-4℃ / min and holding for 5-7h;

[0050] S32, heating to 950-1000℃ at a heating rate of 0.5-2℃ / min and holding for 3-4h;

[0051] S33, heating to 1350-1400℃ at a heating rate of 0.1-1℃ / min, pressurizing to 25-35 MPa, and holding for 2-3h.

[0052] In a third aspect of the present application, the application provides the use of the tin oxide-based target material of the first aspect of the present application in film plating, batteries, transistors, and display panels.

[0053] In some embodiments of the present application, the film plating comprises DC direct current power magnetron sputtering film plating.

[0054] In some embodiments of the present application, the battery comprises a photovoltaic heterojunction battery or a perovskite battery.

[0055] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art upon examination of the following or can be learned by practice of the application. DETAILED DESCRIPTION

[0056] The concept and the technical effects of the present application will be described clearly and completely in the following embodiments, so as to fully understand the purpose, features and effects of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, but not all the embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present application, without creative labor, are within the protection scope of the present application.

[0057] The specific conditions not mentioned in the detailed description are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments not mentioned by the manufacturer are conventional products that can be purchased on the market.

[0058] The tantalum oxide powder, zinc oxide powder and tungsten oxide powder used in the detailed description are purchased from Sigma Aldrich (Shanghai) Trading Co., Ltd.; and the gadolinium oxide powder is purchased from Sigma Aldrich (Shanghai) Trading Co., Ltd.

[0059] Example 1

[0060] The present embodiment provides a SnO2-based target material and a preparation method thereof. The preparation raw material of the SnO2-based target material is composed of the following components in mass fraction:

[0061] 91.5 parts of tin oxide, 3 parts of tantalum oxide, 3 parts of zinc oxide, 1.5 parts of tungsten oxide, 1 part of gadolinium oxide, 1 part of a binder, and 1 part of a plasticizer.

[0062] The binder is polyvinyl alcohol (PVA), and the plasticizer is polyethylene glycol (PEG).

[0063] The preparation method of the SnO2-based target material comprises the following steps:

[0064] 1) Preparation of tin oxide powder:

[0065] The tin oxide powder is prepared by using a chemical precipitation method, and the specific surface area of the powder is measured to be 18 m 2 / g;

[0066] 2) Preparation of mixed oxide powder:

[0067] Purity≥99.99% of tantalum oxide powder, purity≥99.99% of zinc oxide powder, purity≥99.99% of tungsten oxide powder and purity≥99.99% of gadolinium oxide powder with purity≥99.99% of tin oxide powder prepared in step 1) are mixed, and then ball-milled with 0.65 mm and 0.30 mm zirconium beads, and a binder and a plasticizer are added, and after spray drying, a mixed oxide powder is obtained, and the specific surface area of the mixed powder is measured to be 15 m 2 / g, and the loose bulk density is 1.4 g / cm 3 ;

[0068] 3) Green compact forming:

[0069] The mixed powder is injected into a rotary target mold, and cold isostatic pressing (CIP) is used for forming, and the forming pressure is 150 MPa, and after 30 min of static pressure strengthening at room temperature, a target green compact is obtained;

[0070] 4) Debinding and sintering:

[0071] The formed green compact prepared in step 3) is placed in a hot-pressing sintering furnace, vacuumized to -90 Pa, and after the pressure is stabilized, oxygen is introduced until the gas pressure is 0 Pa, and the temperature is raised to 610 ℃ at a rate of 2 ℃ / min for debinding, and the temperature is maintained for 2.5 h; after debinding, hot-pressing sintering is performed, and the temperature is raised to 640 ℃ at a rate of 3 ℃ / min, and the temperature is maintained for 6 h; the temperature is raised to 970 ℃ at a rate of 1 ℃ / min, and the temperature is maintained for 3.5 h; the temperature is raised to 1370 ℃ at a rate of 0.5 ℃ / min, and the pressure is increased, and after the pressure reaches 30 MPa, the temperature and the pressure are maintained for 2.5 h; and the temperature is cooled to room temperature, and a multi-doped tin oxide target is obtained;

[0072] 5) Processing:

[0073] The sintered target is placed in a lathe for grinding, and 800 mesh grinding wheel is used for rough grinding for 6 h, and 400 mesh grinding wheel is used for fine grinding for 6 h, and finally a SnO2-based target with a relatively smooth surface and appropriate size is obtained.

[0074] Example 2

[0075] The SnO2-based target provided by the embodiment and a preparation method thereof are disclosed.

[0076] The preparation raw material of the SnO2-based target consists of the following components in mass fraction:

[0077] The binder is polyvinyl alcohol (PVA), and the plasticizer is polyethylene glycol (PEG).

[0078] The steps of the preparation method of the SnO2-based target are as follows:

[0079] 1) Preparation of tin oxide powder:

[0080] The tin oxide powder was prepared using a chemical precipitation method, and the specific surface area of the powder was measured to be 18 m 2 / g;

[0081] 2) Preparation of mixed oxide powder:

[0082] Purified tantalum oxide powder with a purity of ≥99.99%, purified zinc oxide powder with a purity of ≥99.99%, purified tungsten oxide powder with a purity of ≥99.99%, and purified gadolinium oxide powder with a purity of ≥99.99% were prepared in corresponding mass fractions, and the tin oxide powder prepared in step 1) was mixed with the five oxide powders. Ball milling was performed using 0.65 mm and 0.30 mm zirconium beads for grinding, and a binder and a plasticizer were added. After spray drying, the mixed oxide powder was obtained, and the specific surface area of the mixed powder was measured to be 15 m 2 / g, and the loose bulk density was 1.4 g / cm 3 ;

[0083] 3) Green compact formation:

[0084] The mixed powder was injected into a rotating target mold using CIP molding, and the molding pressure was 120 MPa. After 30 min of static pressure strengthening at room temperature, the target green compact was obtained;

[0085] 4) Debinding and sintering:

[0086] The formed green compact prepared in step 3) was placed in a hot-pressing sintering furnace, vacuum was drawn to -90 Pa, oxygen was introduced after the pressure was stabilized, the gas pressure was 0 Pa, the temperature was raised to 640℃ at a rate of 2.5℃ / min for debinding, and the temperature was maintained for 3h. After debinding, hot sintering was performed, the temperature was raised to 650℃ at a rate of 3℃ / min, and the temperature was maintained for 6h. The temperature was raised to 960℃ at a rate of 1℃ / min, and the temperature was maintained for 3.5h. The temperature was raised to 1390℃ at a rate of 0.5℃ / min, and the pressure was increased. After the pressure reached 30 MPa, the temperature and pressure were maintained for 2.5h. The target material was cooled to room temperature, and a multi-doped tin oxide target material was obtained;

[0087] 5) Processing:

[0088] The sintered target material was placed in a lathe for grinding and cutting. Coarse grinding was performed using an 800 mesh grinding wheel for 6h, and fine grinding was performed using a 400 mesh grinding wheel for 6h. Finally, a relatively smooth and appropriately sized tin oxide-based target material was obtained.

[0089] Example 3

[0090] The SnO2-based target material and its preparation method are provided. The preparation raw material of the SnO2-based target material is composed of the following components in mass fractions:

[0091] SnO2 92 parts, Ta2O3 3 parts, ZnO 3 parts, WO3 1.5 parts, Gd2O3 0.5 parts, binder 2 parts, plasticizer 1.5 parts.

[0092] The binder is polyvinyl alcohol (PVA) and the plasticizer is polyethylene glycol (PEG).

[0093] The preparation method of the SnO2-based target material comprises the following steps:

[0094] 1) Preparation of SnO2 powder:

[0095] The SnO2 powder is prepared by using a chemical precipitation method, and the specific surface area of the powder is measured to be 18 m 2 / g;

[0096] 2) Preparation of mixed oxide powder:

[0097] Prepare the corresponding mass fraction of the purity ≥ 99.99% of the Ta2O3 powder, the purity ≥ 99.99% of the ZnO powder, the purity ≥ 99.99% of the WO3 powder and the purity ≥ 99.99% of the Gd2O3 powder, and the SnO2 powder prepared in step 1), mix the five kinds of oxide powders, and then ball mill while using 0.65 mm and 0.30 mm zirconium beads for grinding, and add a binder and a plasticizer, and then spray dry to obtain the mixed oxide powder, and the specific surface area of the mixed powder is measured to be 15 m 2 / g, and the loose bulk density is 1.4 g / cm 3 ;

[0098] 3) Green compact forming:

[0099] The mixed powder is injected into a rotating target mold, and CIP forming is used, and the forming pressure is 180 MPa, and the target material green compact is obtained after static pressure strengthening;

[0100] 4) Debinding and sintering:

[0101] The formed green compact prepared in step 3) is placed in a hot-pressing sintering furnace, vacuumized to -90 Pa, and oxygen is introduced after the pressure is stabilized, to 0 Pa, and the temperature is raised to 610 ℃ at a heating rate of 1.5 ℃ / min for debinding, and the temperature is maintained for 3 h; after debinding, hot sintering is performed, and the temperature is raised to 630 ℃ at a rate of 3 ℃ / min, and the temperature is maintained for 6 h; the temperature is raised to 990 ℃ at a rate of 1 ℃ / min, and the temperature is maintained for 3.5 h; the temperature is raised to 1360 ℃ at a rate of 0.5 ℃ / min, and the pressure is increased, and the temperature and the pressure are maintained for 2.5 h after the pressure reaches 30 MPa; and the temperature is cooled to room temperature, and the multi-doped SnO2 target material is obtained;

[0102] 5) Processing:

[0103] The sintered target material is put into a lathe for grinding, 800 mesh grinding wheel is used for rough grinding for 6h, 400 mesh grinding wheel is used for fine grinding for 6h, and finally the tin oxide-based target material with smooth surface and appropriate size is obtained.

[0104] Example 4

[0105] The embodiment provides a SnO2-based target material and a preparation method thereof, and the difference between the embodiment and the embodiment 1 is only that the mass fractions of some raw material components are different: 92.5 parts of tin oxide, 1 part of tungsten oxide, 0.5 part of gadolinium oxide, and the rest of the raw material components and the preparation method are consistent with the embodiment 1.

[0106] Example 5

[0107] The embodiment provides a SnO2-based target material and a preparation method thereof, and the difference between the embodiment and the embodiment 1 is only that the mass fractions of some raw material components are different: 92.5 parts of tin oxide, 2.5 parts of tantalum oxide, 2.5 parts of zinc oxide, and the rest of the raw material components and the preparation method are consistent with the embodiment 1.

[0108] Example 6

[0109] The embodiment provides a SnO2-based target material and a preparation method thereof, and the difference between the embodiment and the embodiment 1 is only that the mass fractions of some raw material components are different: 93 parts of tin oxide, 2.5 parts of tantalum oxide, 2.5 parts of zinc oxide, 1 part of tungsten oxide, and the rest of the raw material components and the preparation method are consistent with the embodiment 1.

[0110] Example 7

[0111] The embodiment provides a SnO2-based target material and a preparation method thereof, and the difference between the embodiment and the embodiment 1 is only that the mass fractions of some raw material components are different: 93.5 parts of tin oxide, 2.5 parts of tantalum oxide, 2.5 parts of zinc oxide, 1 part of tungsten oxide, 0.5 part of gadolinium oxide, and the rest of the raw material components and the preparation method are consistent with the embodiment 1.

[0112] Example 8

[0113] The embodiment provides a SnO2-based target material and a preparation method thereof, and the difference between the embodiment and the embodiment 3 is only that the mass fractions of some raw material components are different: 93.5 parts of tin oxide, 2 parts of tantalum oxide, 2 parts of zinc oxide, and the rest of the raw material components and the preparation method are consistent with the embodiment 3.

[0114] Example 9

[0115] The embodiment provides a SnO2-based target material and a preparation method thereof. The embodiment is different from the embodiment 3 only in that the mass fractions of some preparation raw material components are different: 94.5 parts of tin oxide, 2 parts of tantalum oxide, 2 parts of zinc oxide, 1 part of tungsten oxide, and 0.5 part of gadolinium oxide, and the rest of the raw material components and the preparation method are consistent with the embodiment 3.

[0116] Comparative example 1

[0117] The comparative example provides a SnO2-based target material and a preparation method thereof. The comparative example is different from the embodiment 1 only in that the mass fractions of some preparation raw material components are different: 100 parts of tin oxide, and no tantalum oxide, zinc oxide, tungsten oxide and gadolinium oxide are added, and the rest of the raw material components and the preparation method are consistent with the embodiment 1.

[0118] Comparative example 2

[0119] The comparative example provides a SnO2-based target material and a preparation method thereof. The comparative example is different from the embodiment 1 only in that the mass fractions of some preparation raw material components are different: 97 parts of tin oxide and 3 parts of tantalum oxide, and no zinc oxide, tungsten oxide and gadolinium oxide are added, and the rest of the raw material components and the preparation method are consistent with the embodiment 1.

[0120] Comparative example 3

[0121] The comparative example provides a SnO2-based target material and a preparation method thereof. The comparative example is different from the embodiment 1 only in that the mass fractions of some preparation raw material components are different: 97 parts of tin oxide and 3 parts of zinc oxide, and no tantalum oxide, tungsten oxide and gadolinium oxide are added, and the rest of the raw material components and the preparation method are consistent with the embodiment 1.

[0122] Comparative example 4

[0123] The comparative example provides a SnO2-based target material and a preparation method thereof. The comparative example is different from the embodiment 1 only in that the mass fractions of some preparation raw material components are different: 94 parts of tin oxide, 3 parts of zinc oxide and 3 parts of tantalum oxide, and no tungsten oxide and gadolinium oxide are added, and the rest of the raw material components and the preparation method are consistent with the embodiment 1.

[0124] Comparative example 5

[0125] The comparative example provides a SnO2-based target material and a preparation method thereof. The comparative example is different from the embodiment 1 only in that the mass fractions of some preparation raw material components are different: 92.5 parts of tin oxide, 3 parts of zinc oxide, 3 parts of tantalum oxide and 1.5 parts of tungsten oxide, and no gadolinium oxide is added, and the rest of the raw material components and the preparation method are consistent with the embodiment 1.

[0126] Comparative example 6

[0127] The comparative example provides a Sn02-based target material and a preparation method thereof. The comparative example is different from example 1 only in that the mass fraction of some of the raw material components is different: 97.5 parts of tin oxide, 1.5 parts of tungsten oxide, and 1 part of gadolinium oxide, without adding tantalum oxide and zinc oxide, and the rest of the raw material components and the preparation method are consistent with example 1.

[0128] Comparative example 7

[0129] The comparative example provides a Sn02-based target material and a preparation method thereof. The comparative example is different from example 1 only in that the mass fraction of some of the raw material components is different: 97.5 parts of tin oxide, 1.5 parts of tungsten oxide, and 1 part of gadolinium oxide, without adding tantalum oxide and zinc oxide, and the rest of the raw material components and the preparation method are consistent with example 1.

[0130] Comparative example 8

[0131] The comparative example provides a Sn02-based target material and a preparation method thereof. The comparative example is different from example 1 only in that the mass fraction of some of the raw material components is different: 97.5 parts of tin oxide, 1.5 parts of tungsten oxide, and 1 part of gadolinium oxide, without adding tantalum oxide and zinc oxide, and the rest of the raw material components and the preparation method are consistent with example 1.

[0132] The comparative example shows that the target material cracks during hot-pressing sintering, and therefore cannot meet the application requirements.

[0133] Comparative example 9

[0134] The comparative example provides a Sn02-based target material and a preparation method thereof. The comparative example is different from example 1 only in that the mass fraction of some of the raw material components is different: 97.5 parts of tin oxide, 1.5 parts of tungsten oxide, and 1 part of gadolinium oxide, without adding tantalum oxide and zinc oxide, and the rest of the raw material components and the preparation method are consistent with example 1.

[0135] The comparative example shows that the target material cracks during hot-pressing sintering, and therefore cannot meet the application requirements.

[0136] Test example

[0137] The tin oxide-based target materials prepared in each example and comparative example are detected, the density of the final target material is tested using the Archimedes drainage method, and the resistivity of the target material is tested using a resistivity meter.

[0138] The test results and the oxide raw material component fractions of each example and comparative example are shown in Table 1:

[0139] Table 1 Oxide raw material component fractions and density and resistivity test results of each example and comparative example

[0140]

[0141]

[0142] From the above test results, it can be seen that, the comparative example 1, because only tin oxide is used without doping other oxide components, the density of the sintered SnO2-based target material is low, only 6.04 g / m 3 , and the resistivity is high, reaching 2.47 x 10 7 Ω·cm, so it has almost no conductivity; the comparative example 2, by doping with tantalum oxide, greatly improves the sintering density of the SnO2-based target material, and causes the resistivity of the target material to decrease, but the resistivity is still high; the comparative example 3, by doping with zinc oxide, can also improve the sintering density of the SnO2-based target material, and significantly reduces the resistivity of the target material, but it is still difficult to meet the requirements of DC power magnetron sputtering coating; the comparative example 4, by simultaneously doping with tantalum oxide and zinc oxide, achieves a significant increase in the density of the target material, reaching 6.62 g / m 3 , and the resistivity is further reduced compared with the comparative example 3, but it still does not reach the ideal value; the comparative example 5, on the basis of the comparative example 4, further dopes with tungsten oxide, achieving the technical effects of slightly increasing the density of the target material and further reducing the resistivity, but the resistivity still has room for reduction; the comparative example 6, on the basis of the comparative example 1, simultaneously dopes with tungsten oxide and gadolinium oxide, achieving the technical effect of significantly reducing the resistivity of the SnO2-based target material, but the sintering density is too low, the prepared target material has low density, and therefore the resistivity still cannot reach the ideal resistance value; the comparative example 7, on the basis of the comparative example 4, further dopes with gadolinium oxide, achieving the technical effects of slightly increasing the density of the target material and further reducing the resistivity, but the resistivity still has room for reduction; the comparative example 8 simultaneously dopes with four oxides, but because the doping amount of tantalum oxide and zinc oxide is too high, it causes large lattice distortion of tin oxide, and the target material cracks during sintering; similarly, the comparative example 9 also causes large lattice distortion of tin oxide because of the too high doping amount of gadolinium oxide, and the target material cracks during sintering, both of which cannot be applied.

[0143] The comparative examples 1-9 reasonably configure four oxides, and by controlling the appropriate doping amount of the four oxides, the technical effects of preparing a SnO2-based target material with high density and ultra-low resistivity are achieved, wherein the reasonable doping of tantalum oxide and zinc oxide improves the density of the target material and reduces the resistivity, and on this basis, the reasonable addition of tungsten oxide and gadolinium oxide sufficiently reduces the resistivity of the target material, and finally a sintered body with good density and further reduced resistivity compared with the comparative examples is obtained. The prepared target material is very excellent in terms of resistivity and density, and the processed target material can be stably used for DC power magnetron sputtering coating.

[0144] In summary, in the present application, the reasonable doping of the four oxides of tantalum oxide, zinc oxide, tungsten oxide and gadolinium oxide in the tin oxide-based target material achieves the technical effect of improving the density of the target material and sufficiently reducing the resistivity, and the optimal addition amount of each doped oxide is explored. When tantalum oxide is doped, since the radius of Ta element is 0.064 nm, which is smaller than that of Sn element, the Ta element can replace the position of Sn element to form Sn (1-x) Ta x O2 solid solution, and since the valence of Ta element is 5+, which is higher than that of Sn element, the replacement of Ta element will introduce electron holes in SnO2, increase the carrier concentration, and thus improve the conductivity of SnO2; in addition, the replacement of Ta element will also affect the crystal structure of SnO2, making the lattice constant change, and with the increase of the doping amount of Ta element, the replacement of Ta element will make the crystal structure of SnO2 more compact and stable; the replacement of Ta element will also affect the sintering behavior and density of SnO2, and with the increase of the doping amount of Ta element, the sintering temperature of SnO2 will decrease, and the density after sintering will also increase, because the replacement of Ta element will promote the grain growth and grain boundary diffusion of SnO2, thus accelerating the sintering process and reducing the porosity. When zinc oxide is doped, since the radius of Zn 2+ element is 0.074 nm, which is larger than that of Sn 4+ element, when Zn replaces Sn, the adjacent oxygen atoms will be separated to form oxygen vacancies, promote the development of SnO2 lattice, and produce a large number of electrons, greatly increasing the conductivity; at the same time, within a certain doping range, ZnO reacts with SnO2 at high temperature to form Zn2SnO4, filling the gaps between particles and greatly strengthening the sintering densification of the target material, achieving the effect of assisting the sintering of tin oxide-based target material and promoting the sintering densification; however, too much ZnO doping will cause the sintering cracking and delamination of the target material. When tungsten oxide is doped, since W 6+ element is an important cation dopant in tin oxide-based transparent conductive materials, the replacement of Sn 4+ by W 6+Among the common doped elements, the highest valence state can produce more free electrons; at the same time, the doping of W element also helps to produce more carriers and maintain the structural ability of tin oxide. When gadolinium oxide is doped, the 4f electrons of Gd ions will form a hybrid orbital with SnO2, thereby increasing the carrier concentration, so that more electrons can transition to the conduction band; at the same time, after doping, the energy band structure of SnO2 is more matched with the perovskite layer of the solar cell, which may result in higher charge transfer at the interface between the electron transport layer and the perovskite, and less recombination at the interface; in addition, as a rare earth element, Gd also has strong light absorption, which will change the optical properties of SnO2 and affect its application in optoelectronic devices; although Gd doping can improve the conductivity of SnO2, too high a doping concentration may cause lattice distortion, affecting the stability and other physical properties of SnO2; therefore, it is very important to choose the appropriate doping concentration.

[0145] In addition, compared with the existing ITO target material for heterojunction and perovskite solar cells, the present application selects tin oxide as the main material, which is cheaper and more environmentally friendly, and improves the density of the target material by doping Ta and Zn elements, and the density of the prepared target material reaches 6.61g / m 3 ~ 6.72g / m 3 At the same time, by doping W and Gd elements to reduce the resistivity of the target material and adjust the photoelectric performance of tin oxide, the resistivity of the prepared target material is reduced to 1.07x10 -3 Ω·cm~1.74x10 -3 Ω·cm, the tin oxide-based target material prepared by the present application is suitable for DC power magnetron sputtering coating, and can also be applied to photovoltaic heterojunction cells and perovskite cells, has good light transmittance, low resistivity, and improves the conversion efficiency of the cell.

[0146] The above describes the embodiments of the present application in detail, but the present application is not limited to the above embodiments, and within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the purpose 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. A tin oxide-based target material, characterized in that, The raw materials for preparation include, by mass parts: 91.5-94.5 parts tin oxide, 2-3 parts tantalum oxide, 2-3 parts zinc oxide, 1-1.5 parts tungsten oxide, 0.5-1 part gadolinium oxide, 0.5-2 parts binder, and 0.5-1.5 parts plasticizer; The tin oxide-based target material is prepared by the following method: S1. Mix the raw materials, ball mill, and spray dry. S2. Static pressing is used to obtain the green blank; S3. Degreasing, hot pressing and sintering, to obtain tin oxide-based target material; The hot pressing sintering includes the following steps: S31. Keep warm at 600~650℃ for 5~7 hours; S32. Keep warm at 950~1000℃ for 3~4 hours; S33. Incubate at 1350~1400℃ and 25~35MPa for 2~3 hours.

2. The tin oxide-based target material according to claim 1, characterized in that, The density of the tin oxide-based target is ≥6.5 g / m³. 3 .

3. The tin oxide-based target material according to claim 1, characterized in that, The resistivity of the tin oxide-based target is ≤1×10⁻⁶. -2 Ω·cm.

4. The tin oxide-based target material according to any one of claims 1-3, characterized in that, The static pressure for step S2 is 100~200MPa.

5. The tin oxide-based target material according to claim 4, characterized in that, The degreasing temperature in step S3 is 600~650℃, and the time is 2~3h.

6. The application of the tin oxide-based target as described in any one of claims 1 to 5 in coating, batteries, transistors, and display panels.

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