TW202122609A - Method for manufacturing vacuum deposition tablet, oxide transparent conductive film, and tin-oxide-based sintered body - Google Patents

Abstract

To provide a method for manufacturing an oxide transparent conductive film to be provided on a reverse surface side of a heterojunction solar cell, a vacuum deposition tablet serving as a vacuum deposition source when forming the transparent conductive film, and a tin-oxide-based sintered body that constitutes said tablet. A vacuum deposition tablet according to the present invention is characterized by: having tin oxide as a main component; including 0.5 mass% to 10 mass% zinc oxide, 0.1 mass% to 0.5 mass% germanium oxide, and 0.1 mass% to 1.0 mass% tantalum oxide; and being constituted by a tin-oxide-based sintered body having a density of 3.75 g/cm3 to 4.40 g/cm3. An oxide transparent conductive film according to the present invention is characterized by: having tin oxide as a main component; including 0.5 mass% to 10 mass% zinc oxide, 0.1 mass% to 0.5 mass% germanium oxide, and 0.1 mass% to 1.0 mass% tantalum oxide; and having, at a film thickness of 100 nm, a light transmittance of 90% or more for wavelengths of 450 nm to 800 nm.

Description

Method for manufacturing vapor deposition board, oxide transparent conductive film, and tin oxide sintered body

The present invention relates to a light-emitting diode (Light Emitting Diode, LED), organic electroluminescence (Electro-Luminescence, EL) and other light devices (devices), solar energy Transparent conductive oxide films for batteries, lenses, and optical films. In particular, it relates to an oxide transparent conductive film used as a transparent conductive film on the back side of a heterojunction solar cell. A plate for vapor deposition that is a vapor deposition source of a transparent conductive film, and a method for producing a tin oxide sintered body constituting the plate for vapor deposition.

The oxide transparent conductive films currently used in the market generally have high conductivity and high transmittance in the visible light region. This feature can be used flexibly in the electrodes of liquid crystal display elements, solar cells, and other light-receiving elements. It is also used as a heat-reflection film, anti-static film, and anti-static film for automotive windows or buildings. A transparent heating element for mist is used.

In addition, as the transparent conductive oxide film, the transparent conductive film containing a dopant (α), an indium oxide (In ₂ O ₃ +α), and a zinc oxide (ZnO+α) Transparent conductive film and tin oxide (SnO ₂ +α) transparent conductive film. The most used oxide transparent conductive film is indium oxide. Indium oxide containing tin as a dopant is called ITO (Indium Tin Oxide) film, and it is widely used because it is easy to obtain a low-resistance transparent conductive oxide film. .

On the other hand, the tin oxide-based (SnO ₂ +α) transparent conductive film is also _{inferior in terms of electrical resistance compared with the indium oxide-based (In 2} O ₃ +α) transparent conductive film, but it is excellent in transparency. , And chemically stable, thermally stable and other reasons, and in addition to being used for solar cells, it is also used for a wide range of applications such as flat panel displays or touch panels. In addition, regarding solar cells, in order to improve conversion efficiency, for example, a heterojunction solar cell as described in Patent Document 1 has been developed. Moreover, in a heterojunction type solar cell, a transparent conductive film is formed on both the front side and the back side to be irradiated with sunlight. The transparent conductive film on the front side is used to transfer electricity to the surface electrode existing in a limited space. , And require low resistance. On the other hand, the electrode on the back surface has a larger area than the surface electrode and exists to cover the entire back surface depending on the situation. Therefore, the transparent conductive film on the back surface is hardly required to have low resistance, but requires higher transparency.

However, the tin oxide-based (SnO ₂ +α) transparent conductive film is generally industrially formed by a wet method such as a spray method or a partial dry method such as a chemical vapor deposition (chemical vapor deposition, CVD) method. . However, these methods are not suitable for uniformizing the film thickness of the transparent conductive film over a large area, and the control of the film formation process is also difficult. In addition, in the wet method, there are pollutants generated during film formation due to the use of a chlorinated solution. The situation of the chlorine-based gas. Furthermore, in the CVD method, a large number of defects may be formed on the formed transparent conductive film. Therefore, it is desired to form a transparent conductive film with few defects using a dry method.

Regarding the formation of a transparent conductive film by the dry method, Patent Document 2 and Patent Document 3 disclose tin oxide-based thin film forming materials used in sputtering targets. That is, Patent Document 2 discloses a technique for forming a tin oxide-based thin film material whose sintered body density is at most 6.79 g/cm ^{3 by containing Co, Nb, etc., and Patent Document 3 discloses that by containing Nb} For example, a technology that can form a tin oxide-based sintered body of a transparent conductive film with ^{a specific resistance of 8.33×10 -3 Ω·cm and a transmittance of 87.4%.}

However, in recent years, film formation by the vapor deposition method, which is superior in productivity of the transparent conductive film compared to the sputtering method, has become the mainstream. Patent Document 4 discloses that by including tungsten oxide in tin oxide, the specific resistance is 3×10 ³ Ω·cm or more and 5×10 ⁶ Ω·cm or less, and a film thickness of 100 nm, with an oxide transparent conductive film with a light transmittance of 95% or more at a wavelength of 500 nm to 600 nm, and its vapor deposition Source tin oxide based sintered body board technology. [Prior Art Document] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2011-199045 (refer to paragraph 0004 and paragraph 0061) [Patent Document 2] Japanese Patent Laid-Open No. 2000-273622 (refer to Claim 1, Claim 6, Table 1) [Patent Document 3] Japanese Patent Laid-Open No. 2000-281431 (refer to Claim 1, Claim 12, and Table 5) [Patent Document 4] Japanese Patent Laid-Open No. 2016-117610 (refer to Claim 1-Claim 4)

[The problem to be solved by the invention] However, the tin oxide-based transparent conductive film described in Patent Document 3 or Patent Document 4 has a higher transmittance than ITO. However, when a tin oxide-based transparent conductive film is applied to the back side of a heterojunction solar cell, the transmittance (87.4%) of the transparent conductive film described in Patent Document 3 has an insufficient problem.

On the other hand, the tin oxide sintered body described in Patent Document 4 containing tungsten oxide has a transparent conductive oxide film that can be formed into a film with a light transmittance of 95% or more at a wavelength of 500 nm to 600 nm at a thickness of 100 nm The advantages. However, since tungsten oxide does not form a compound with tin oxide, it is easy to produce density unevenness in the vapor deposition board or between the vapor deposition boards, which may cause the vapor deposition board to crack during film formation, or the formed oxide film Even in the tin oxide-based sintered body described in Patent Document 4, there is a problem that the reliability of the transparent conductive film is slightly inferior to the defects such as uneven characteristics of the transparent conductive film.

The present invention focuses on such problems, and its subject is to provide a plate for vapor deposition and a transparent conductive oxide film with high transmittance in which the defects during film formation are less likely to occur, and to provide a structure that constitutes the vapor deposition plate. Method for manufacturing tin oxide sintered body of plate for plating. [Means to solve the problem]

In order to solve the above-mentioned problem, the inventors conducted intensive research and found that it can be achieved by using zinc oxide, germanium oxide, and tantalum oxide, which form compounds with tin oxide, as dopants. The present invention has been completed based on this technical discovery.

That is, the first invention of the present invention is a plate for vapor deposition characterized by comprising a tin oxide sintered body, the tin oxide sintered body is mainly composed of tin oxide and contains 0.5% by mass or more and 10% by mass or less 0.1% by mass or more and 0.5% by mass or less of germanium oxide, 0.1% by mass or more and 1.0% by mass or less of tantalum oxide, with a density of 3.75 g/cm ³ or more and 4.40 g/cm ³ or less. Furthermore, the second invention of the present invention is an oxide transparent conductive film characterized by containing tin oxide as a main component, containing 0.5% by mass or more and 10% by mass or less of zinc oxide, and 0.1% by mass or more and 0.5% by mass or less The third invention is a transparent conductive oxide film as described in the second invention, characterized in that the film thickness is 100 nm and the wavelength is 450 nm to 800 nm The light transmittance is 90% or more; the fourth invention is the oxide transparent conductive film according to the second or third invention, characterized in that the specific resistance value is 9×10 ³ Ω·cm or more and 5×10 ⁶ Ω·cm or less.

Secondly, the fifth invention is A method for manufacturing a tin oxide sintered body, the tin oxide sintered body constituting the vapor deposition plate according to the first invention, and the method for manufacturing the tin oxide sintered body is characterized by having In the first step, tin oxide powder, zinc oxide powder, germanium oxide powder, and tantalum oxide powder are mixed with pure water and a dispersant to prepare a slurry, and the resulting slurry is spray-dried to obtain a mixed powder. The mixed powder is pre-sintered to obtain the pre-fired powder; In the second step, un-calcined tin oxide powder, zinc oxide powder, germanium oxide powder, and tantalum oxide powder are mixed with the obtained calcined powder, and granulated to obtain granulated powder; In the third step, the obtained granulated powder is press-molded to obtain a molded body; and The fourth step is to formally sinter the obtained molded body to obtain the tin oxide sintered body, and The calcining temperature in the first step is 1350°C or more and 1450°C or less, and, The main sintering temperature in the fourth step is 50° C. or more lower than the maximum temperature of the calcining temperature in the first step, and is in the range of 1300° C. or more and 1400° C. or less. [Effects of the invention]

According to the vapor deposition sheet of the present invention, since zinc oxide, germanium oxide, and tantalum oxide, which can form compounds with tin oxide, are used as dopants, it is difficult to produce density variations in the vapor deposition sheet or between the vapor deposition sheets. As a result, it is possible to prevent defects such as cracks of the vapor deposition plate during film formation and uneven properties of the formed oxide transparent conductive film.

Therefore, it is possible to stably form an oxide transparent conductive film with a light transmittance of 90% or more at a wavelength of 450 nm to 800 nm at a film thickness of 100 nm. Therefore, it has the following effect that the oxide can be transparently and electrically conductive. The film is preferably used as a transparent conductive film for forming flat-panel displays, touch panels, light-emitting devices, etc. with good visibility, and is particularly preferably used as a transparent conductive film on the back side of heterojunction solar cells. membrane.

The present invention uses zinc oxide, germanium oxide, and tantalum oxide, which form compounds with tin oxide, as dopants, and can provide a vapor deposition plate that is not prone to defects during film formation, thereby also providing a high permeability Rate of oxide transparent conductive film. Hereinafter, embodiments of the present invention will be described in detail.

[Additional raw material: dopant] (Zinc oxide) The plate for vapor deposition containing the tin oxide sintered body of the present invention can be added by setting the raw material input amount of zinc oxide to 0.5% by mass or more and 10% by mass or less. The density of the tin oxide sintered body containing tin oxide as a main component is suppressed within an appropriate range, and a high transmittance of the oxide transparent conductive film obtained by film formation is obtained. By containing zinc oxide, the density of the tin oxide sintered body can be easily controlled within ^{an appropriate range of 3.75 g/cm 3} or more and 4.40 g/cm ³ or less, and at the same time, a stable tin oxide sintered body can be obtained. Mass productivity.

In addition, when the raw material input amount of zinc oxide is less than 0.5% by mass, the light transmittance at a wavelength of 450 nm to 800 nm at a film thickness of 100 nm may not reach 90% or more, which is not preferable. In addition, when the raw material input amount of zinc oxide exceeds 10% by mass, the density of the tin oxide sintered body constituting the vapor deposition plate is higher than 4.40 g/cm ³ , and the vapor deposition plate is broken during the film formation process, resulting in The membrane efficiency is reduced, so it is not good.

In addition, the density of the tin oxide-based sintered body was measured using the Archimedes method.

(Germanium oxide: germanium dioxide) The vapor deposition board containing the tin oxide sintered body of the present invention can be made of tin oxide as the main component by setting the raw material input amount of germanium oxide (germanium dioxide) to 0.1% by mass or more and 0.5% by mass or less. The density of the tin oxide sintered body is suppressed within an appropriate range.

When the raw material input amount of germanium oxide (germanium dioxide) is less than 0.1% by mass, the density of the tin oxide sintered body constituting the vapor deposition plate is less than 3.75 g/cm ³ , which is called spattering during film formation. (Splash) The scattering of material particles causes defects in the oxide transparent conductive film, so it is not good. In the case where the raw material input amount of germanium oxide (germanium dioxide) exceeds 0.5% by mass, the vapor deposition plate may be broken during the film formation process, and the film formation efficiency may decrease, which is undesirable. Moreover, when the input amount of raw materials exceeds 0.5% by mass, the density of the tin oxide sintered body is often higher than 4.40 g/cm ³ , but when the content of germanium oxide (germanium dioxide) is too large, even the tin oxide sintered body When the density of the film is lower than 4.40 g/cm ³ , the plate for vapor deposition may crack.

(Tantalum Oxide: Tantalum Pentoxide) The vapor deposition sheet containing the tin oxide sintered body of the present invention can suppress the formation of the film by setting the raw material input amount of tantalum oxide (tantalum pentoxide) to 0.1% by mass or more and 1.0% by mass or less. The specific resistance value of the oxide transparent conductive film prevents it from becoming too high.

In addition, when the raw material input amount of tantalum oxide (tantalum pentoxide) is less than 0.1% by mass and when it exceeds 1.0% by mass, the specific resistance of the transparent conductive oxide film obtained by film formation is present. The value is higher than 5×10 ⁶ Ω·cm, so it is not good.

[Method for manufacturing tin oxide sintered body] The method for producing the tin oxide sintered body constituting the vapor deposition plate of the present invention is characterized by having In the first step, tin oxide powder, zinc oxide powder, germanium oxide powder, and tantalum oxide powder are mixed with pure water and a dispersant to prepare a slurry, and the resulting slurry is spray-dried to obtain a mixed powder. The mixed powder is pre-sintered to obtain the pre-fired powder; In the second step, un-calcined tin oxide powder, zinc oxide powder, germanium oxide powder, and tantalum oxide powder are mixed with the obtained calcined powder, and granulated to obtain granulated powder; In the third step, the obtained granulated powder is press-molded to obtain a molded body; and The fourth step is to formally sinter the obtained molded body to obtain the tin oxide sintered body, and The calcining temperature in the first step is 1350°C or more and 1450°C or less, and, The main sintering temperature in the fourth step is 50° C. or more lower than the maximum temperature of the calcining temperature in the first step, and is in the range of 1300° C. or more and 1400° C. or less.

Hereinafter, each step will be explained.

(First step) The tin oxide powder, zinc oxide powder, germanium oxide powder, and tantalum oxide powder are blended so as to have the desired composition, and then pure water, dispersant, and binders are added as needed, and mixed and stirred to prepare a slurry-like raw material (Slurry) After that, the obtained slurry is spray-dried using a spray dryer or the like to obtain a mixed powder. In addition, as the adhesive, there is no particular limitation as long as it is a known adhesive that disappears or vaporizes by heating, and polyvinyl alcohol or the like can be used.

Next, the obtained mixed powder is heat-treated at a temperature of 1350° C. or higher and 1450° C. or lower to obtain a powder in which the additive elements are compounded with each other. In the present invention, the heat treatment in the first step is referred to as pre-sintering, the temperature is referred to as the calcining temperature, and the obtained powder is referred to as the calcined powder. When the unevenness of the particle size of the calcined powder is large, it is preferable to perform sieving to make the particle size uniform.

In addition, when the calcining temperature is less than 1350°C, there is a problem that the density and size of the tin oxide sintered body obtained in the fourth step described later become large. On the other hand, if the calcining temperature exceeds 1450°C, zinc oxide evaporates, making composition control difficult, and there is a problem that the desired sintered body structure cannot be obtained. Therefore, it is preferable to set the calcining temperature to 1350°C or more and 1450°C or less, more preferably 1380°C or more and 1420°C or less, and to set the calcining time to 15 hours or more and 25 hours or less.

(Second step) Next, in the calcined powder obtained in the first step, a powder containing tin oxide powder, zinc oxide powder, germanium oxide powder, and tantalum oxide powder is blended so as to become the composition of the tin oxide sintered body finally produced. After calcining the powder, a binder, a dispersant, and a lubricant are added, mixed and stirred to prepare a slurry-like raw material (slurry), and then granulated using a spray dryer or the like to obtain a granulated powder.

Here, the content of the calcined powder is 50% by mass or more and 70% by mass or less, preferably 55% by mass or more and 65% by mass, relative to 100% by mass of the total powder amount used to form the granulated powder Make deployment.

In the case where the content of the calcined powder exceeds 70% by mass, the sedimentation of the calcined powder occurs quickly when the slurry is made, and it is different from the uncalcined powder (including uncalcined tin oxide powder, zinc oxide powder, The germanium oxide powder and the tantalum oxide powder) separate and become a cause of variation in composition during granulation, which is undesirable. Furthermore, it is difficult to control the shrinkage behavior of granulated powders with compositional deviations during the main sintering in the fourth step described later. Furthermore, since the shrinkage behavior is unstable, the density may be lower than the desired density, or the strength may be low, and cracks or breakage may occur, making it difficult to produce the desired tin oxide sintered body.

On the other hand, when the content of calcined powder is as small as less than 50% by mass, the amount of uncalcined powder (including uncalcined tin oxide powder, zinc oxide powder, germanium oxide powder, and tantalum oxide powder) increases. In the fourth step described later, particle growth is likely to occur, which promotes Neck Growth between the particles and increases the strength of the tin oxide sintered body. On the other hand, it is used as a plate for vapor deposition. During use, it is easy to produce a temperature difference between the outermost surface and the inside, and due to the difference in thermal expansion, the board is likely to be damaged, which is not good.

Due to these conditions, the calcined powder is blended under the condition that the content of the calcined powder is 50% by mass or more and 70% by mass relative to 100% by mass of the total powder amount, whereby the main sintering in the fourth step can be easily performed By controlling the shrinkage at the time, stable strength can be obtained, and a tin oxide sintered body having a desired density can be easily obtained.

Moreover, as a method of mixing calcined powder and uncalcined powder (including uncalcined tin oxide powder, zinc oxide powder, germanium oxide powder, and tantalum oxide powder), it is preferable to use a mixer that does not easily pulverize the powder during mixing. mixing. Moreover, when mixing, it is more preferable to add pure water, a binder, and a dispersant to form a slurry. Furthermore, it is preferable to add 0.5% by mass or more and 1% by mass or less of stearic acid that functions as a lubricant when performing metal mold pressing during molding in the third step described later.

(The third step) Next, the granulated powder obtained in the second step is press-molded to form a molded body. The molding of the granulated powder is preferably performed by pressing with a metal mold. Since the shrinkage caused by the main sintering can be controlled by the combination of the pre-fired powder ratio in the second step, the pressing pressure during molding, and the main sintering temperature in the fourth step described later, the shrinkage caused by the main sintering can be controlled, so the target or the plate The size of is roughly determined by the size during forming in the third step.

In the case of forming a target for sputtering, it is preferable to perform press molding under a pressure of 98 MPa or more. When molding is performed under a pressure of less than 98 MPa, there is a case where a density suitable for the target cannot be obtained in the main sintering in the fourth step described later, which is not preferable. As a pressurizing method that can obtain a high pressure, for example, Cold Isostatic Press (CIP) can be used.

In the case of forming a plate for vapor deposition, it is preferable to perform press molding at a pressure of 49 MPa or more and 147 MPa or less. When it is less than 49 MPa, the density may not be sufficiently increased in the final sintering in the fourth step, and when it is higher than 147 MPa, the density may become too high, which is not good. As a pressure method that can appropriately apply a pressure of 49 MPa or more and 147 MPa or less, for example, a mechanical pressing method in which pressure is applied in a metal mold can be used.

(Fourth step) Next, by sintering the formed body obtained in the third step, compounded calcined powder and uncalcined powder (including uncalcined tin oxide powder, zinc oxide powder, germanium oxide powder, And tantalum oxide powder) compounded tin oxide sintered body. The gas environment at the time of main sintering may be any of oxygen, air, and vacuum, but sintering in the air can be performed inexpensively and is optimal. In the present invention, the final sintering process performed to obtain the tin oxide sintered body in the fourth step is referred to as the main sintering, and the heat treatment temperature is referred to as the main sintering temperature.

Hereinafter, the heat treatment step for obtaining the tin oxide-based sintered body will be described in detail.

First, the formed body obtained in the third step is placed in a heat treatment furnace, and oxygen is introduced into the heat treatment furnace at a ratio of 100 L (liter)/min ^{per 1 m 3 of the furnace inner volume to make the oxygen in the heat treatment gas atmosphere} The concentration is 30% or more (volume ratio), the oxygen concentration is set higher than that in the atmosphere (oxygen content 21%), and the heat treatment (debinding agent treatment) is performed at 200°C or more and 700°C or less for 20 hours or more.

After that, the main sintering is performed, and the main sintering temperature is 50°C or more lower than the calcining temperature performed in the first step (that is, 50°C or more lower than the highest temperature of the calcining temperature in the first step), which is 1300°C or more and The range of 1400° C. or lower is preferably 1330° C. or higher and 1380° C. or lower, and it may be selected so that the density of the obtained tin oxide sintered body is 3.75 g/cm ³ or higher and 4.40 g/cm ³ or lower.

When the main sintering temperature is as low as less than 1300°C, the density of the obtained tin oxide sintered body may be less than 3.75 g/cm ³ , and the sintering of the vapor deposition board containing the tin oxide sintered body may occur. Insufficient performance, the board becomes powdery, and splashes frequently occur.

Moreover, when the difference between the main sintering temperature and the pre-sintering temperature is less than 50°C or the main sintering temperature is higher than the pre-sintering temperature, the density of the resulting tin oxide sintered body may become too high. Cracks occurred in the vapor deposition plate of the body. Therefore, in the present invention, the upper limit of the main sintering temperature is 1400°C which is 50°C lower than the upper limit of the calcining temperature of 1450°C.

In addition, the main sintering treatment is preferably performed within a range of 20 hours or more and 30 hours or less, and the optimal time is 23 hours or more and 28 hours or less. When it is less than 20 hours, the main sintering may not be completed and the density may not become sufficiently high. Moreover, even if it exceeds 30 hours, the sintering hardly proceeds, which is not good. If it is within the range of 20 hours or more and 30 hours or less, the proper main sintering processing time can be achieved. Therefore, high productivity can be achieved without unnecessary power, and a high-quality tin oxide-based sintered body can be obtained. Plates for plating.

In addition, the vapor deposition plate of the present invention including the tin oxide-based sintered body can be used as a cylindrical plate having a diameter of 10 mm or more and 50 mm or less, and a height of 5 mm or more and 60 mm or less, for example. In addition, this cylindrical shape is sometimes called a pellet.

[Oxide Transparent Conductive Film] By using the vapor deposition plate as a vapor deposition source and forming a film by a vapor deposition method, the oxide transparent conductive film of the present invention can be obtained, and the obtained oxide transparent conductive film can achieve high transmittance.

That is, it is possible to obtain a high transmittance with a light transmittance of 90% or more at a wavelength of 450 nm to 800 nm at a film thickness of 100 nm measured by a visible spectrophotometer, and a specific resistance value of 9×10 ³ Ω· cm or more and 5×10 ⁶ Ω·cm or less oxide transparent conductive film.

[Heterojunction type solar cell] When the film thickness is 100 nm, the light transmittance at the wavelength of 450 nm to 800 nm is 90% or more and the specific resistance value is 9×10 ³ Ω·cm or more and 5×10 ⁶ Ω·cm or less The oxide transparent conductive film can be preferably used for the transparent conductive film on the back side of the heterojunction solar cell as shown in FIG. 1.

The heterojunction solar cell includes, for example, an n-type single crystal silicon layer 5 located in the center, an i-type amorphous silicon layer 4 laminated on both sides of the n-type single crystal silicon layer 5, and an i-type amorphous silicon layer 4 located on both sides of the n-type single crystal silicon layer 5. The p-type amorphous silicon layer 3 on the surface side and laminated on the i-type amorphous silicon layer 4, the n-type amorphous silicon layer 6 on the back side and laminated on the i-type amorphous silicon layer 4, is laminated on the p-type amorphous silicon layer 4. The low-resistance transparent conductive film 2 of the crystalline silicon layer 3 is laminated on the n-type amorphous silicon layer 6 and the high-transmittance transparent conductive film 7 is partially provided on the surface of the low-resistance transparent conductive film 2 The metal electrode 1 and the back metal electrode 8 provided across the entire surface of the transparent conductive film 7 with high transmittance.

In addition, a transparent conductive oxide film with a light transmittance of 90% or more at a wavelength of 450 nm to 800 nm at a film thickness of 100 nm and a specific resistance value of 9×10 ³ Ω·cm or more and 5×10 ^{6 Ω·cm or less} It can be preferably used for the transparent conductive film on the back side of the heterojunction type solar cell as shown in FIG. 1 (that is, the transparent conductive film 7 with high transmittance). [Example]

Hereinafter, the embodiments of the present invention will also be described in detail by citing reference examples for comparison.

[Example 1] A mixed powder prepared such that the zinc oxide powder is 5.0% by mass, the germanium oxide powder is 0.3% by mass, the tantalum oxide powder is 0.5% by mass, and the remainder is tin oxide powder (94.2% by mass).

With respect to 39% by mass of the mixed powder, 60% by mass of pure water, 0.5% by mass of ammonium polycarboxylate as a dispersant, and 0.5% by mass of PVA (polyvinyl alcohol) as a binder were added, and mixed with a mixer. A slurry-like raw material (slurry) is prepared, and then the slurry is spray-dried using a spray dryer to prepare a mixed powder before calcining.

The prepared mixed powder was pre-sintered in the air at 1400° C. for 20 hours, and then sieved to obtain a calcined powder as the first raw material powder.

Next, prepare the second raw material powder prepared so that the zinc oxide powder is 5.0% by mass, the germanium oxide powder is 0.3% by mass, the tantalum oxide powder is 0.5% by mass, and the remainder is tin oxide powder (94.2% by mass). The uncalcined powder was prepared as the second raw material powder so that the mixing ratio of the first raw material powder, that is, the calcined powder was 60% by mass to obtain a mixed powder.

With respect to 98.5% by mass of the mixed powder, 0.5% by mass of the PVA as a binder, 0.5% by mass of the polycarboxylate ammonium salt as a dispersant, and 0.5% by mass of stearic acid as a lubricant are added, and then, The mixture is stirred for 12 hours or more with a mixer to prepare a slurry-like raw material (slurry), and the slurry is spray-dried using a spray dryer, thereby obtaining granulated powder.

Then, the obtained granulated powder was put into a predetermined mold, and a uniaxial press was used for compression molding under a pressure of 90 MPa to obtain a molded body with a diameter of 20.5 mm and a height of 7.5 mm. This compact was sintered under the following conditions.

The main sintering process is performed in a heat treatment furnace where oxygen is introduced at a rate of 100 L (liter)/min ^{per 1 m 3 of the furnace internal volume, and the oxygen concentration in the heat treatment furnace reaches 30% or more by volume.}

First, after raising the temperature from room temperature to 500°C in 15 hours, the temperature was raised to 800°C in 11 hours to remove the binder in the molded body. After that, the temperature in the heat treatment furnace was set to 1350° C. and maintained for 20 hours to perform main sintering to produce a tin oxide-based sintered body constituting the vapor deposition plate of Example 1.

Then, the manufactured plate for vapor deposition was irradiated with a high-power (accelerating voltage of 15 kV, output of 24 kW) electron beam (EB) to form a transparent conductive film with a thickness of 100 nm on the glass substrate.

[Evaluation of vapor deposition board containing tin oxide-based sintered body] 1) Density The density of the manufactured vapor deposition board was measured using Archimedes' method. As a result, the density of this sample was 4.10 g/cm ³ . The preferable density range of the plate for vapor deposition is in the range of 3.75 g/cm ³ or more and 4.40 g/cm ³ or less.

2) Confirmation of the state during vapor deposition During the vapor deposition process, no cracking of the vapor deposition plate was confirmed, and the occurrence of splashing was not confirmed.

[Evaluation of Transparent Conductive Film] 1) Transmittance A spectrophotometer (manufactured by JASCO Corporation, V-670) was used to measure the light transmittance at a wavelength of 450 nm to 800 nm at a film thickness of 100 nm. As a result, the average transmittance of this sample was 93%, which obtained the pass criterion of the present invention. That is, a good result of more than 90%.

2) Specific resistance value Furthermore, it can be confirmed that the specific resistance value of the formed transparent conductive film is 3×10 ⁵ Ω·cm, which satisfies the pass criteria of the present invention, namely 9×10 ³ Ω·cm or more and 5×10 ⁶ Ω ·Conditions below cm, have the required conductivity.

Regarding the production conditions of the vapor deposition sheet of Example 1 [ _{the blending amount (mass%) of inorganic materials (SnO 2} , ZnO, GeO ₂ , Ta ₂ O ₅ ), the pre-sintering temperature (°C) of the mixed powder, the size of the molded body Main sintering temperature (°C)], evaluation results of the vapor deposition board [density of the board (g/cm ³ ), whether the board cracks and splashes during the vapor deposition process], and the transparent conductive film formed The evaluation results [average transmittance (%) and specific resistance value (Ω·cm)] are shown in Table 1-1 and Table 1-2.

[Example 2] Except that the blending amount of the zinc oxide powder was changed to 0.5% by mass, and the remaining tin oxide powder was changed to 98.7% by mass, the same procedure as in Example 1 was carried out to obtain a vapor deposition plate of Example 2 except for this point.

The obtained plate for vapor deposition was evaluated in the same manner as in Example 1. As a result, the density was 3.90 g/cm ³ , and the occurrence of plate cracking or splashing during the vapor deposition process could not be confirmed.

Furthermore, a transparent conductive film with a thickness of 100 nm was formed in the same manner as in Example 1. The transparent conductive film had an average transmittance of 91% and a specific resistance value of 5×10 ⁴ Ω·cm.

As in Example 1, the production conditions of the vapor deposition sheet, the evaluation results of the vapor deposition sheet, and the evaluation results of the formed transparent conductive film of Example 2 are shown in Table 1-1 and Table 1-2 .

[Example 3] Except that the blending amount of the zinc oxide powder was changed to 10.0% by mass, and the remaining tin oxide powder was changed to 89.2% by mass, the same procedure as in Example 1 was carried out to obtain a vapor deposition sheet of Example 3.

The obtained plate for vapor deposition was evaluated in the same manner as in Example 1. As a result, the density was 4.25 g/cm ³ , and the occurrence of plate cracking or splashing during the vapor deposition process could not be confirmed.

Furthermore, a transparent conductive film with a film thickness of 100 nm was formed in the same manner as in Example 1. The average transmittance of the transparent conductive film was 95% and the specific resistance value was 8×10 ⁵ Ω·cm.

As in Example 1, the production conditions of the vapor deposition plate of Example 3, the evaluation results of the vapor deposition plate, and the evaluation results of the formed transparent conductive film are shown in Table 1-1 and Table 1-2 .

[Example 4] The blending amount of zinc oxide powder was changed to 0.5% by mass, the blending amount of germanium oxide powder was changed to 0.1% by mass, the blending amount of tantalum oxide powder was changed to 0.1% by mass, and the remaining tin oxide powder was changed to Except for 99.3% by mass, in the same manner as in Example 1, a vapor deposition plate of Example 4 was obtained.

The obtained plate for vapor deposition was evaluated in the same manner as in Example 1. As a result, the density was 3.75 g/cm ³ , and the occurrence of plate cracking or splashing during the vapor deposition process could not be confirmed.

Furthermore, a transparent conductive film with a thickness of 100 nm was formed in the same manner as in Example 1. The average transmittance of the transparent conductive film was 90%, and the specific resistance value was 3×10 ⁴ Ω·cm.

As in Example 1, the production conditions of the vapor deposition plate of Example 4, the evaluation results of the vapor deposition plate, and the evaluation results of the formed transparent conductive film are shown in Table 1-1 and Table 1-2 .

[Example 5] The blending amount of zinc oxide powder was changed to 0.5% by mass, the blending amount of germanium oxide powder was changed to 0.5% by mass, the blending amount of tantalum oxide powder was changed to 1.0% by mass, and the remaining tin oxide powder was changed to Except for 98.0% by mass, in the same manner as in Example 1, a vapor deposition plate of Example 5 was obtained.

The obtained plate for vapor deposition was evaluated in the same manner as in Example 1. As a result, the density was 4.05 g/cm ³ , and the occurrence of plate cracking or splashing during the vapor deposition process could not be confirmed.

Furthermore, a transparent conductive film with a film thickness of 100 nm was formed in the same manner as in Example 1. The transparent conductive film had an average transmittance of 91% and a specific resistance value of 9×10 ⁵ Ω·cm.

As in Example 1, the production conditions of the vapor deposition plate, the evaluation results of the vapor deposition plate, and the evaluation results of the formed transparent conductive film of Example 5 are shown in Table 1-1 and Table 1-2 .

[Example 6] The blending amount of zinc oxide powder was changed to 10.0% by mass, the blending amount of germanium oxide powder was changed to 0.1% by mass, the blending amount of tantalum oxide powder was changed to 0.1% by mass, and the remaining tin oxide powder was changed to Except for 89.8% by mass, in the same manner as in Example 1, a vapor deposition plate of Example 6 was obtained.

The obtained plate for vapor deposition was evaluated in the same manner as in Example 1. As a result, the density was 4.20 g/cm ³ , and the occurrence of plate cracking or splashing during the vapor deposition process could not be confirmed.

Furthermore, a transparent conductive film with a thickness of 100 nm was formed in the same manner as in Example 1. The average transmittance of the transparent conductive film was 94%, and the specific resistance value was 2×10 ⁴ Ω·cm.

As in Example 1, the production conditions of the vapor deposition plate of Example 6, the evaluation results of the vapor deposition plate, and the evaluation results of the formed transparent conductive film are shown in Table 1-1 and Table 1-2 .

[Example 7] The blending amount of zinc oxide powder was changed to 10.0% by mass, the blending amount of germanium oxide powder was changed to 0.5% by mass, the blending amount of tantalum oxide powder was changed to 1.0% by mass, and the remaining tin oxide powder was changed to Except for 88.5 mass %, it carried out similarly to Example 1, and obtained the vapor deposition board of Example 7.

The obtained plate for vapor deposition was evaluated in the same manner as in Example 1. As a result, the density was 4.40 g/cm ³ , and the occurrence of plate cracking or splashing during the vapor deposition process could not be confirmed.

Furthermore, a transparent conductive film with a film thickness of 100 nm was formed in the same manner as in Example 1. The average transmittance of the transparent conductive film was 96%, and the specific resistance value was 5×10 ⁶ Ω·cm.

As in Example 1, the production conditions of the vapor deposition plate, the evaluation results of the vapor deposition plate, and the evaluation results of the formed transparent conductive film of Example 7 are shown in Table 1-1 and Table 1-2 .

[Example 8] Except that the calcining temperature was changed to 1450°C and the main sintering temperature was changed to 1400°C, in the same manner as in Example 6, the vapor deposition plate of Example 8 was obtained.

The obtained plate for vapor deposition was evaluated in the same manner as in Example 1. As a result, the density was 4.28 g/cm ³ , and the occurrence of plate cracking or splashing during the vapor deposition process could not be confirmed.

Furthermore, a transparent conductive film with a thickness of 100 nm was formed in the same manner as in Example 1. The average transmittance of the transparent conductive film was 94%, and the specific resistance value was 5×10 ⁴ Ω·cm.

As in Example 1, the production conditions of the vapor deposition plate, the evaluation results of the vapor deposition plate, and the evaluation results of the formed transparent conductive film of Example 8 are shown in Table 1-1 and Table 1-2 .

[Example 9] Except that the calcining temperature was changed to 1350°C and the main sintering temperature was changed to 1300°C, in the same manner as in Example 6, the vapor deposition plate of Example 9 was obtained.

The obtained plate for vapor deposition was evaluated in the same manner as in Example 1. As a result, the density was 3.97 g/cm ³ , and the occurrence of plate cracking or splashing during the vapor deposition process could not be confirmed.

Furthermore, a transparent conductive film with a thickness of 100 nm was formed in the same manner as in Example 1. The average transmittance of the transparent conductive film was 94%, and the specific resistance value was 9×10 ³ Ω·cm.

As in Example 1, the production conditions of the vapor deposition board, the evaluation results of the vapor deposition board, and the evaluation results of the formed transparent conductive film of Example 9 are shown in Table 1-1 and Table 1-2 .

[Example 10] Except that the calcining temperature was changed to 1450°C and the main sintering temperature was changed to 1400°C, in the same manner as in Example 5, a vapor deposition plate of Example 10 was obtained.

The obtained plate for vapor deposition was evaluated in the same manner as in Example 1. As a result, the density was 4.13 g/cm ³ , and the occurrence of plate cracking or splashing during the vapor deposition process could not be confirmed.

Furthermore, a transparent conductive film with a film thickness of 100 nm was formed in the same manner as in Example 1. The average transmittance of the transparent conductive film was 91% and the specific resistance value was 7×10 ⁵ Ω·cm.

As in Example 1, the production conditions of the vapor deposition plate, the evaluation results of the vapor deposition plate, and the evaluation results of the formed transparent conductive film of Example 10 are shown in Table 1-1 and Table 1-2 .

[Example 11] Except that the calcining temperature was changed to 1350°C and the main sintering temperature was changed to 1300°C, in the same manner as in Example 5, a vapor deposition plate of Example 11 was obtained.

The obtained plate for vapor deposition was evaluated in the same manner as in Example 1. As a result, the density was 4.01 g/cm ³ , and the occurrence of plate cracking or splashing during the vapor deposition process could not be confirmed.

Furthermore, a transparent conductive film with a thickness of 100 nm was formed in the same manner as in Example 1. The average transmittance of the transparent conductive film was 91% and the specific resistance value was 1×10 ⁶ Ω·cm.

As in Example 1, the production conditions of the vapor deposition plate of Example 11, the evaluation results of the vapor deposition plate, and the evaluation results of the formed transparent conductive film are shown in Table 1-1 and Table 1-2 .

[Reference example 1] Except for changing the blending amount of the zinc oxide powder to 0.45% by mass and the remaining tin oxide powder to 98.8% by mass, the same procedure as in Example 1 was carried out to obtain a vapor deposition sheet of Reference Example 1.

The obtained plate for vapor deposition was evaluated in the same manner as in Example 1. As a result, the density was 4.00 g/cm ³ , and the occurrence of plate cracking or splashing during the vapor deposition process could not be confirmed.

Furthermore, a transparent conductive film with a thickness of 100 nm was formed in the same manner as in Example 1. The average transmittance of the transparent conductive film was 87% and the specific resistance value was 1×10 ⁵ Ω·cm.

As in Example 1, the production conditions of the vapor deposition plate of Reference Example 1, the evaluation results of the vapor deposition plate, and the evaluation results of the formed transparent conductive film are shown in Table 1-1 and Table 1-2 .

[Reference example 2] Except that the blending amount of the zinc oxide powder was changed to 10.5% by mass, and the remaining tin oxide powder was changed to 88.7% by mass, the same procedure as in Example 1 was carried out to obtain a plate for vapor deposition of Reference Example 2 except for this point.

The obtained plate for vapor deposition was evaluated in the same manner as in Example 1. As a result, the density was 4.45 g/cm ^3. Cracking of the plate during the vapor deposition process was confirmed, but the occurrence of splashing was not confirmed.

Furthermore, a transparent conductive film with a thickness of 100 nm was formed in the same manner as in Example 1. The average transmittance of the transparent conductive film was 95% and the specific resistance value was 9×10 ⁵ Ω·cm.

As in Example 1, the production conditions of the vapor deposition plate of Reference Example 2, the evaluation results of the vapor deposition plate, and the evaluation results of the formed transparent conductive film are shown in Table 1-1 and Table 1-2 .

[Reference example 3] Except that the blending amount of the germanium oxide powder was changed to 0.05% by mass, and the remaining tin oxide powder was changed to 94.5% by mass, the same procedure as in Example 1 was carried out to obtain a vapor deposition plate of Reference Example 3.

The obtained plate for vapor deposition was evaluated in the same manner as in Example 1. As a result, the density was 3.70 g/cm ³ , and cracking of the plate during the vapor deposition process was not confirmed, but the occurrence of spatter was confirmed.

Furthermore, a transparent conductive film with a thickness of 100 nm was formed in the same manner as in Example 1. The average transmittance of the transparent conductive film was 92%, and the specific resistance value was 3×10 ⁵ Ω·cm.

As in Example 1, the production conditions of the vapor deposition plate of Reference Example 3, the evaluation results of the vapor deposition plate, and the evaluation results of the formed transparent conductive film are shown in Table 1-1 and Table 1-2 .

[Reference example 4] Except that the blending amount of the germanium oxide powder was changed to 0.55 mass%, and the remaining tin oxide powder was changed to 94.0 mass%, the same procedure as in Example 1 was carried out to obtain a plate for vapor deposition of Reference Example 4, except for this point.

The obtained plate for vapor deposition was evaluated in the same manner as in Example 1. As a result, the density was 4.35 g/cm ^3. Cracking of the plate during the vapor deposition process was confirmed, but the occurrence of splashing was not confirmed.

Furthermore, a transparent conductive film with a film thickness of 100 nm was formed in the same manner as in Example 1. The average transmittance of the transparent conductive film was 92%, and the specific resistance value was 8×10 ⁴ Ω·cm.

As in Example 1, the production conditions of the vapor deposition plate of Reference Example 4, the evaluation results of the vapor deposition plate, and the evaluation results of the formed transparent conductive film are shown in Table 1-1 and Table 1-2 .

[Reference example 5] Except that the amount of tantalum oxide was changed to 0.05% by mass, and the remaining tin oxide powder was changed to 94.7% by mass, the same procedure as in Example 1 was carried out to obtain a vapor deposition plate of Reference Example 5.

The obtained plate for vapor deposition was evaluated in the same manner as in Example 1. As a result, the density was 4.08 g/cm ³ , and the occurrence of plate cracking or splashing during the vapor deposition process could not be confirmed.

Furthermore, a transparent conductive film with a thickness of 100 nm was formed in the same manner as in Example 1. The average transmittance of the transparent conductive film was 92%, and the specific resistance value was 7×10 ⁶ Ω·cm.

As in Example 1, the production conditions of the vapor deposition plate of Reference Example 5, the evaluation results of the vapor deposition plate, and the evaluation results of the formed transparent conductive film are shown in Table 1-1 and Table 1-2 .

[Reference example 6] Except that the amount of tantalum oxide was changed to 1.05 mass%, and the remaining tin oxide powder was changed to 93.7 mass%, the same procedure as in Example 1 was carried out to obtain a vapor deposition plate of Reference Example 6.

The obtained plate for vapor deposition was evaluated in the same manner as in Example 1. As a result, the density was 4.12 g/cm ³ , and the occurrence of plate cracking or splashing during the vapor deposition process could not be confirmed.

Furthermore, a transparent conductive film with a film thickness of 100 nm was formed in the same manner as in Example 1. The average transmittance of the transparent conductive film was 93% and the specific resistance value was 9×10 ⁶ Ω·cm.

As in Example 1, the production conditions of the vapor deposition plate of Reference Example 6, the evaluation results of the vapor deposition plate, and the evaluation results of the formed transparent conductive film are shown in Table 1-1 and Table 1-2 .

[Reference example 7] Except that the calcining temperature was changed to 1340° C. and the main sintering temperature was changed to 1290° C., in the same manner as in Example 1, a plate for vapor deposition of Reference Example 7 was obtained.

The obtained plate for vapor deposition was evaluated in the same manner as in Example 1. As a result, the density was 3.70 g/cm ³ , and cracking of the plate during the vapor deposition process was not confirmed, but the occurrence of spatter was confirmed.

Furthermore, a transparent conductive film with a thickness of 100 nm was formed in the same manner as in Example 1. The average transmittance of the transparent conductive film was 91% and the specific resistance value was 2×10 ⁶ Ω·cm.

As in Example 1, the production conditions of the vapor deposition plate of Reference Example 7, the evaluation results of the vapor deposition plate, and the evaluation results of the formed transparent conductive film are shown in Table 1-1 and Table 1-2 .

[Reference example 8] Except that the calcining temperature was changed to 1460° C. and the main sintering temperature was changed to 1410° C., in the same manner as in Example 1, a plate for vapor deposition of Reference Example 8 was obtained.

The obtained plate for vapor deposition was evaluated in the same manner as in Example 1. As a result, the target composition was not obtained due to the high calcining temperature, and the density was 3.68 g/cm ³ , and the plate was not able to be confirmed during the vapor deposition process. It broke, but the occurrence of splashing was confirmed.

Furthermore, a transparent conductive film with a film thickness of 100 nm was formed in the same manner as in Example 1. The average transmittance of the transparent conductive film was 90% and the specific resistance value was 6×10 ⁶ Ω·cm.

As in Example 1, the production conditions of the vapor deposition plate of Reference Example 8, the evaluation results of the vapor deposition plate, and the evaluation results of the formed transparent conductive film are shown in Table 1-1 and Table 1-2 .

[Reference Example 9] Except that the calcining temperature was changed to 1350° C. and the main sintering temperature was changed to 1400° C., in the same manner as in Example 1, a plate for vapor deposition of Reference Example 9 was obtained.

The obtained plate for vapor deposition was evaluated in the same manner as in Example 1. As a result, the density was 4.64 g/cm ^3. Cracking of the plate during the vapor deposition process was confirmed, but the occurrence of splashing was not confirmed.

Furthermore, a transparent conductive film with a thickness of 100 nm was formed in the same manner as in Example 1. The transparent conductive film had an average transmittance of 91% and a specific resistance value of 8×10 ⁴ Ω·cm.

As in Example 1, the production conditions of the vapor deposition plate of Reference Example 9, the evaluation results of the vapor deposition plate, and the evaluation results of the formed transparent conductive film are shown in Table 1-1 and Table 1-2 .

[Table 1-1] Board composition Sintering conditions SnO ₂ (mass%) ZnO (mass%) GeO ₂ (mass %) Ta ₂ O ₅ (mass %) Burn-in temperature (℃) Formal sintering temperature (℃) Example 1 94.2 5.0 0.3 0.5 1400 1350 Example 2 98.7 0.5 0.3 0.5 1400 1350 Example 3 89.2 10.0 0.3 0.5 1400 1350 Example 4 99.3 0.5 0.1 0.1 1400 1350 Example 5 98.0 0.5 0.5 1.0 1400 1350 Example 6 89.8 10.0 0.1 0.1 1400 1350 Example 7 88.5 10.0 0.5 1.0 1400 1350 Example 8 89.8 10.0 0.1 0.1 1450 1400 Example 9 89.8 10.0 0.1 0.1 1350 1300 Example 10 98.0 0.5 0.5 1.0 1450 1400 Example 11 98.0 0.5 0.5 1.0 1350 1300 Comparative example 1 98.8 0.45 0.3 0.5 1400 1350 Comparative example 2 88.7 10.5 0.3 0.5 1400 1350 Comparative example 3 94.5 5.0 0.05 0.5 1400 1350 Comparative example 4 94.0 5.0 0.55 0.5 1400 1350 Comparative example 5 94.7 5.0 0.3 0.05 1400 1350 Comparative example 6 93.7 5.0 0.3 1.05 1400 1350 Comparative example 7 94.2 5.0 0.3 0.5 1340 1290 Comparative example 8 94.2 5.0 0.3 0.5 1460 1410 Comparative example 9 94.2 5.0 0.3 0.5 1350 1400

[Table 1-2] Board evaluation Transparent conductive film evaluation Density (g/cm ³ ) rupture Splash Transmittance (%) Specific resistance value (Ω·cm) Example 1 4.10 no no 93 3×10 ⁵ Example 2 3.90 no no 91 5×10 ⁴ Example 3 4.25 no no 95 8×10 ⁵ Example 4 3.75 no no 90 3×10 ⁴ Example 5 4.05 no no 91 9×10 ⁵ Example 6 4.20 no no 94 2×10 ⁴ Example 7 4.40 no no 96 5×10 ⁶ Example 8 4.28 no no 94 5×10 ⁴ Example 9 3.97 no no 94 9×10 ³ Example 10 4.13 no no 91 7×10 ⁵ Example 11 4.01 no no 91 1×10 ⁶ Comparative example 1 4.00 no no 87 1×10 ⁵ Comparative example 2 4.45 Have no 95 9×10 ⁵ Comparative example 3 3.70 no Have 92 3×10 ⁵ Comparative example 4 4.35 Have no 92 8×10 ⁴ Comparative example 5 4.08 no no 92 7×10 ⁶ Comparative example 6 4.12 no no 93 9×10 ⁶ Comparative example 7 3.70 no Have 91 2×10 ⁶ Comparative example 8 3.68 no Have 90 6×10 ⁶ Comparative example 9 4.64 Have no 91 8×10 ⁴

[Confirmation] (1) Example (1-1) It was confirmed that the plates for vapor deposition of Examples 1 to 11 did not break or spatter during the vapor deposition process, and could form a transparent conductive film efficiently. (1-2) Furthermore, it was confirmed that the formed transparent conductive film has very high transparency with a light transmittance of 90% or more at a wavelength of 450 nm to 800 nm at a film thickness of 100 nm, and the specific resistance value also meets the pass criteria That is, the conditions are 9×10 ³ Ω·cm or more and 5×10 ⁶ Ω·cm or less.

(2) Reference Example (2-1) In Reference Example 1 where it was confirmed that the blending amount of zinc oxide was too small (0.45 mass%), the transmittance of the formed transparent conductive film was 87%, which could not reach 90% or more. On the contrary, In Reference Example 2 where the blending amount of zinc oxide was too large (10.5 mass %), the density of the board became too high (4.45 g/cm ³ ), and cracking of the board occurred during the vapor deposition process. (2-2) Furthermore, it was confirmed that in Reference Example 3 where the blending amount of germanium oxide was too small (0.05% by mass), the board density (3.70 g/cm ³ ) could not be sufficiently increased, and spatter occurred during the vapor deposition process. On the contrary, In Reference Example 4 where the blending amount of germanium oxide was too large (0.55 mass %), the density of the board became high (4.35 g/cm ³ ), and cracking of the board occurred during the vapor deposition process. (2-3) Furthermore, it was confirmed that in Reference Example 5 where the blended amount of tantalum oxide was too small (0.05% by mass) and Reference Example 6 where the blended amount of tantalum oxide was too large (1.05% by mass), the specific resistance value became too high (Reference example 5: 7×10 ⁶ Ω·cm, reference example 6: 9×10 ⁶ Ω·cm). (2-4) In addition, _{the blending amount of inorganic materials (SnO 2} , ZnO, GeO ₂ , Ta ₂ O ₅ ) is reasonable, but the pre-sintering temperature (1350°C or more and 1450°C or less) and the formal sintering temperature (compared to the aforementioned pre-sintering temperature) The highest temperature of the firing temperature is 50°C or more lower, and is 1300°C or more and 1400°C or less). In Reference Example 7 to Reference Example 8, where the main firing temperature is higher than the pre-firing temperature, the density of the board changes. It is too low to enter the proper range (3.75 g/cm ³ or more and 4.40 g/cm ³ or less), and the density of the board is too low in Reference Example 7 to Reference Example 8, splashing occurred during the evaporation process, and the board density was too high In Reference Example 9, the board cracked during the vapor deposition process.

[Repeat Evaluation Test] Regarding the occurrence of cracks in the vapor deposition plate during the vapor deposition process, 10 plates of the same composition were produced, and the number of cracked plates was confirmed.

The samples used in the evaluation were the vapor deposition plates of Example 1, Example 4, Example 7, Reference Example 2, and Reference Example 4, as well as existing products with high transmittance (described in Patent Document 4). Tungsten oxide-containing tin oxide sintered body board: Reference Example 10).

The composition and sintering conditions of each sample, as well as the density of the board and the rate of occurrence of board cracks (number of cracks/10 pieces) are shown in Table 2-1 and Table 2-2.

[table 2-1] Board composition SnO ₂ (mass%) ZnO (mass%) GeO ₂ (mass %) Ta ₂ O ₅ (mass %) WO ₃ (mass %) Example 1 94.2 5.0 0.3 0.5 0.0 Example 4 99.3 0.5 0.1 0.1 0.0 Example 7 88.5 10.0 0.5 1.0 0.0 Reference example 2 88.7 10.5 0.3 0.5 0.0 Reference example 4 94.0 5.0 0.55 0.5 0.0 Reference example 10 95.0 0.0 0.0 0.0 5.0

[Table 2-2] Sintering conditions Board evaluation Burn-in temperature (℃) Formal sintering temperature (℃) Density (g/cm ³ ) Number of ruptures Example 1 1400 1350 4.10 0/10 Example 4 1400 1350 3.75 0/10 Example 7 1400 1350 4.40 0/10 Reference example 2 1400 1350 4.45 8/10 Reference example 4 1400 1350 4.35 6/10 Reference example 10 1250 1350 4.5 5/10

[Confirm] In Example 1, Example 4, and Example 7, the rate of occurrence of plate cracks was 0 pieces/10 pieces. In contrast, Reference Example 2 was 8 pieces/10 pieces, and Reference Example 4 was 6 pieces/10 pieces. And the existing product (Reference Example 10) is 5 pieces/10 pieces, and the superiority of the vapor deposition plates of the examples is confirmed. [Industrial availability]

According to the vapor deposition board of the present invention, it is possible to prevent the failure of the board from cracking during the film formation process or the uneven characteristics of the formed oxide transparent conductive film, and to stably form a wavelength of 450 nm to 800 at a film thickness of 100 nm. Transparent conductive oxide film with a light transmittance of 90% or more in nm Therefore, it has industrial applicability for use as a sheet for a transparent conductive film formed on the back side of a heterojunction solar cell.

1: Surface metal electrode 2: Low resistance transparent conductive film 3: p-type amorphous silicon layer 4: i-type amorphous silicon layer 5: n-type monocrystalline silicon layer 6: n-type amorphous silicon layer 7: Transparent conductive film with high transmittance 8: Metal electrode on the back

Fig. 1 is a structural explanatory diagram showing an example of a heterojunction solar cell.

1: Surface metal electrode

2: Low resistance transparent conductive film

3: p-type amorphous silicon layer

4: i-type amorphous silicon layer

5: n-type monocrystalline silicon layer

6: n-type amorphous silicon layer

7: Transparent conductive film with high transmittance

8: Metal electrode on the back

Claims (5)

A plate for vapor deposition, characterized by comprising a tin oxide sintered body containing tin oxide as a main component, containing 0.5% by mass to 10% by mass of zinc oxide, 0.1% by mass or more, and 0.5% by mass or less of germanium oxide and 0.1% by mass or more and 1.0% by mass or less of tantalum oxide, and the density is 3.75 g/cm ³ or more and 4.40 g/cm ³ or less. A transparent conductive oxide film characterized by containing tin oxide as the main component, containing 0.5% by mass or more and 10% by mass or less of zinc oxide, 0.1% by mass or more and 0.5% by mass or less of germanium oxide, and 0.1% by mass or more And 1.0% by mass or less of tantalum oxide. The oxide transparent conductive film according to claim 2, wherein the light transmittance at a wavelength of 450 nm to 800 nm at a film thickness of 100 nm is 90% or more. The oxide transparent conductive film according to claim 2 or claim 3, wherein the specific resistance value is 9×10 ³ Ω·cm or more and 5×10 ⁶ Ω·cm or less. A method for manufacturing a tin oxide sintered body, the tin oxide sintered body constituting the vapor deposition plate according to claim 1, and the method for manufacturing the tin oxide sintered body is characterized by having: In the first step, tin oxide powder, zinc oxide powder, germanium oxide powder, and tantalum oxide powder are mixed with pure water and a dispersant to prepare a slurry, and the resulting slurry is spray-dried to obtain a mixed powder. The mixed powder is pre-sintered to obtain pre-fired powder In the second step, un-calcined tin oxide powder, zinc oxide powder, germanium oxide powder, and tantalum oxide powder are mixed with the obtained calcined powder, and granulated to obtain granulated powder; In the third step, the obtained granulated powder is press-molded to obtain a molded body; and The fourth step is to formally sinter the obtained molded body to obtain the tin oxide sintered body, and The calcining temperature in the first step is 1350°C or more and 1450°C or less, and The main sintering temperature in the fourth step is 50° C. or more lower than the maximum temperature of the calcining temperature in the first step, and is in the range of 1300° C. or more and 1400° C. or less.

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