Transparent conductive film

Abstract

A transparent conductive film comprising a glass substrate, a first layer, a second layer, and a third layer, wherein: the first layer contains tungsten oxide represented by general formula WO3-x (0≤x≤0.28); the second layer contains tungsten bronze; the third layer contains at least one compound selected from the compound group of SiO2, TiO2, WO3, Nb2O5, Al2O3, ZrO2, Ta2O5, SnO2, Si3N4, LaB6and TiN; and the layers are arranged in the order of the first layer, the second layer and the third layer, with the first layer being closest to the glass substrate.

Description

Transparent conductive film

[0001] The present invention relates to a transparent conductive film.

[0002] Transparent conductive films are used in transparent electrodes such as liquid crystal display elements and solar cells, infrared absorption reflection films, electromagnetic wave shielding films, etc. As the transparent conductive film used for transparent electrodes for liquid crystal display elements, etc., an ITO (Indium Tin Oxide) conductive film is mainly used.

[0003] The ITO conductive film is excellent in high visible light transmittance and low film surface resistance, but is expensive because it uses indium. Therefore, improvements in physical properties such as permeability and conductivity and cost reduction are being promoted.

[0004] As one new candidate material for a transparent conductive substance to replace ITO, tungsten oxide represented by the general formula W ｙ O ｚ and a transparent conductive film of composite tungsten oxide represented by the general formula M ｘ W ｙ O ｚ have been proposed. (Patent Document 1)

[0005] Japanese Patent Application Laid-Open No. 2006-096656

[0006] By the way, when a transparent conductive film formed by depositing tungsten bronze on a glass substrate is used, the haze of the transparent conductive film may increase. Depending on the use of the transparent conductive film, a transparent conductive film with low haze is required.

[0007] [[ID=第31]] One aspect of the present invention aims to provide a transparent conductive film with low haze.

[0008] The transparent conductive film according to one embodiment of the present invention has a glass substrate, a first layer, a second layer, and a third layer, and the first layer contains tungsten oxide represented by the general formula WO ３－ｘ (0 ≦ x ≦ 0.28), the second layer contains tungsten bronze, and the third layer contains SiO ２ , TiO ２ , WO ３ , Nb ２ O ５ , Al ２ O ３ , ZrO２ Ta ２ O ５ , SnO ２ Si ３ N ４ LaB ６ The compounds include one or more selected from the TiN compound group, and are arranged in the order of the first layer, the second layer, and the third layer from a position close to the glass substrate.

[0009] According to one aspect of the present invention, a transparent conductive film with low haze can be provided.

[0010] Figure 1 is an explanatory diagram of a transparent conductive film according to one aspect of the present disclosure. Figure 2 is an explanatory diagram of a transparent conductive film according to another aspect of the present disclosure. Figure 3 is a flow chart of a method for manufacturing a transparent conductive film according to one aspect of the present disclosure.

[0011] The embodiments for carrying out the present invention will be described below with reference to the drawings, but the present invention is not limited to the embodiments described below, and various modifications and substitutions can be made to the embodiments described below without departing from the scope of the present invention. [Transparent conductive film] Figures 1 and 2 show explanatory diagrams of the transparent conductive film of this embodiment. Figures 1 and 2 are cross-sectional views of the first, second, and third layers of the transparent conductive film of this embodiment in a plane along the lamination direction. Since Figure 2 is an example of another configuration of the transparent conductive film of this embodiment, the explanation will mainly use Figure 1, and use Figure 2 as necessary.

[0012] In this specification, the names of components may be prefixed with "1st," "2nd," etc., such as "1st layer," "2nd layer," and "3rd layer." However, these prefixes are merely used to identify the component being described and to avoid confusion, and do not indicate its arrangement, priority, or anything of the sort.

[0013] As shown in Figure 1, the transparent conductive film 10 of this embodiment has a glass substrate 11, a first layer 12, a second layer 13, and a third layer 14. The layers can also be arranged in the order of the first layer 12, the second layer 13, and the third layer 14, starting from a position close to the glass substrate 11.

[0014] The layers of the transparent conductive film of this embodiment will now be described. (1) About each layer (1-1) Glass substrate The glass substrate 11 is a substrate that supports the first layer 12, the second layer 13, and the third layer 14.

[0015] The type of glass contained in the glass substrate 11 is not particularly limited, and any glass can be used. The glass contained in the glass substrate 11 may be one or more types selected from, for example, soda glass, soda-lime glass, borosilicate glass, aluminosilicate glass, chemically strengthened glass, alkali-free glass, etc. Examples of chemically strengthened glass include alkali aluminosilicate glass containing alkali metal oxides and soda glass containing alkali metal oxides.

[0016] The average thickness T11 of the glass substrate 11 is not particularly limited, but may be, for example, 0.5 mm or more and 50.0 mm or less, or 0.5 mm or more and 1.0 mm or less. (1-2) First layer The inventors of the present invention investigated the cause of high haze in a transparent conductive film in which a tungsten bronze film is placed on a glass substrate.

[0017] The investigation revealed that in the transparent conductive film with increased haze, a new phase was formed, likely due to a reaction between components in the tungsten bronze and components in the glass substrate. Therefore, it was inferred that the increased haze in the transparent conductive film was due to the migration and reaction of components in the glass substrate during the deposition of the tungsten bronze film, resulting in the formation of a new compound phase.

[0018] Based on the mechanism by which haze increases in conventional transparent conductive films, the inventors of the present invention conducted further studies. As a result, they discovered that by placing a first layer 12 between the glass substrate 11 and the second layer 13 containing a tungsten bronze film, which can reduce the movement of components from the glass substrate 11 to the second layer 13, a transparent conductive film 10 with reduced haze can be created, thus completing the present invention.

[0019] Therefore, in the transparent conductive film 10 of this embodiment, a first layer 12 can be provided between the glass substrate 11 and the second layer 13. In this case, the first layer 12 is positioned close to the surface of the glass substrate 11. In particular, in this embodiment, the first layer 12 is positioned closer to the glass substrate 11 than the second layer 13. The first layer 12 is composed of a material of the general formula WO３－ｘ It contains tungsten oxide represented by (0 ≤ x ≤ 0.28). The first layer 12 contains the general formula WO ３－ｘ Tungsten oxide represented by (0 ≤ x ≤ 0.28) is given by the general formula WO ３－ｘ It may also be included in the first layer 12 as a film containing tungsten oxide represented by (0 ≤ x ≤ 0.28). Below, the general formula WO ３－ｘ Tungsten oxide, expressed as (0 ≤ x ≤ 0.28), is sometimes simply referred to as tungsten oxide. (1-2-1) Regarding the composition of the first layer, the glass used in the glass substrate contains additives to control various properties of the glass, such as the glass transition temperature. According to the inventors' research, elements such as additives contained in the glass mainly used in the glass substrate, such as Group 1 elements like alkali metals and Group 2 elements like alkaline earth metals, react with tungsten bronze, producing a different phase.

[0020] Therefore, in this embodiment, the transparent conductive film 10 has a first layer 12 placed between the glass substrate 11 and the second layer 13, preventing elements such as additives contained in the glass from reaching the second layer 13 from the glass substrate 11. As a result, it is possible to prevent the formation of a different phase in the second layer 13 and the increase in haze of the transparent conductive film.

[0021] When the first layer 12 contains tungsten oxide, the tungsten oxide is typically tungsten trioxide (WO ３ ) can be used, but it may be reduced. Among the chemical formulas of tungsten oxide described above, in the range of x from 0 to 0.28, the conductivity improves as the amount of reduction increases, so the conductivity of the transparent conductive film when combined with the second layer 13 can be improved.

[0022] The first layer 12 is, as described above, the general formula WO ３－ｘ It can contain tungsten oxide represented by (0 ≤ x ≤ 0.28). Note that the first layer 12 can also be composed solely of tungsten oxide, but this does not exclude the inclusion of unavoidable impurities introduced during the manufacturing process.

[0023] Furthermore, the first layer 12 may also contain a continuous film. In this case, the continuous film may contain tungsten oxide. (Tungsten oxide) Tungsten oxide readily reacts with elements such as alkali metals and alkaline earth metals contained in the glass to form composite tungsten oxide, which is tungsten bronze. For tungsten oxide, it is in stoichiometric ratio WO ３ In that case it is an insulating film, but when reduced it is WO ３－ｘ Because it possesses conductivity when in its composition, it can effectively reduce the resistance value in transparent conductive films.

[0024] Tungsten oxide has a monoclinic or tetragonal crystal structure, and its crystallization allows it to incorporate elements derived from additives such as alkali metals and alkaline earth metals contained in the glass into its voids without altering its crystal structure, thus preventing distortion of the surroundings and increasing haze. For this reason, it is preferable that at least a portion of the tungsten oxide contained in the first layer 12 is crystallized. The presence of crystallized tungsten oxide in the first layer 12 can be confirmed, for example, by measuring the X-ray diffraction pattern, which shows the presence of a diffraction peak corresponding to tungsten oxide.

[0025] Furthermore, tungsten oxide itself, when x (which indicates the amount of oxygen deficiency) is greater than 0, can generate a sufficient amount of free electrons to enhance the absorption and reflection properties in the near-infrared region, thus contributing to the effect of reducing the resistance value in transparent conductive films.

[0026] General formula for tungsten oxide: WO ３－ｘ It is preferable that x satisfies the condition 0 ≤ x ≤ 0.28.

[0027] As described above, when the first layer 12 contains a film containing tungsten oxide, the tungsten oxide can incorporate elements derived from alkali metal elements and alkaline earth metal elements contained in the glass into the voids to form a composite tungsten oxide.

[0028] Therefore, when the first layer 12 contains tungsten oxide, the transparent conductive film of this embodiment has an X-ray diffraction pattern in which the tungsten oxide phase and M ｘ１ WO ｚ１It is preferable to be able to identify the phase and the tungsten bronze phase.

[0029] The tungsten oxide phase is due to the tungsten oxide contained in the first layer 12. ｘ１ WO ｚ１ The phase is formed by the reaction of tungsten oxide with alkali metals and alkaline earth metals contained in the glass. Therefore, M ｘ１ WO ｚ１ The phase element M is one or more elements selected from alkali metals and alkaline earth metals, and x1 can satisfy 0.01 ≤ x1 < 1. z1 is not particularly limited, but for example, it may satisfy 2.5 ≤ z1 ≤ 3.0.

[0030] Alkali metal elements include Li (lithium), Na (sodium), K (potassium), rubidium (Rb), cesium (Cs), and Fr (francium).

[0031] Alkaline earth metal elements refer to alkaline earth metal elements in a broad sense, and include Be (beryllium), Mg (magnesium), Ca (calcium), Sr (strontium), Ba (barium), and Ra (radium).

[0032] The tungsten bronze phase is due to the tungsten bronze contained in the second layer.

[0033] When the first layer 12 contains a film containing tungsten oxide, the transparent conductive film of this embodiment, in its X-ray diffraction pattern, shows that the phases originating from the first layer 12 and the second layer 13 are the tungsten oxide phase and M ｘ１ WO ｚ１ It may consist only of the phase and the tungsten bronze phase. (1-2-2) Regarding the average thickness of the first layer, the average thickness T12 of the first layer 12 is not particularly limited, but for example, the average thickness of the first layer 12 may be 5 nm or more and 1200 nm or less, 10 nm or more and 1200 nm or less, or 30 nm or more and 600 nm or less.

[0034] By setting the average film thickness of the first layer 12 to 5 nm or more, the amount of components contained in the glass substrate 11 that reach the second layer 13 can be particularly reduced. Therefore, the haze of the transparent conductive film 10 in this embodiment can be particularly reduced.

[0035] By making the average film thickness of the first layer 12 1200 nm or less, the coloration of the first layer 12 and the transparent conductive film 10 can be reduced, and the visible light transmittance can be increased. Also, by making the average film thickness of the first layer 12 1200 nm or less, the time required to form the first layer 12 can be shortened, and the productivity of manufacturing the transparent conductive film 10 can be increased. (1-3) Second layer (1-3-1) Composition of the second layer The second layer 13 contains tungsten bronze. The tungsten bronze contained in the second layer 13 may be incorporated into the second layer 13 as a tungsten bronze film.

[0036] The second layer 13 is, for example, general formula A ｘ２ W ｙ２ O ｚ２ It may contain tungsten bronze (composite tungsten oxide) represented by general formula A. ｘ２ W ｙ２ O ｚ２ It is also possible to construct it solely from tungsten bronze, but even in this case, it does not eliminate the possibility of unavoidable impurities being introduced during the manufacturing process.

[0037] In the above general formula, it is preferable that x², y², and z² satisfy the following conditions: 0.2 ≤ x² / y² ≤ 0.5 and 2.5 ≤ z² / y² ≤ 3.0.

[0038] Element A may contain one or more alkali metal elements selected from K (potassium), Rb (rubidium), and Cs (cesium). Some of the alkali metal elements contained in element A may be substituted with one or more elements selected from Na (sodium), Tl (thallium), In (indium), Li (lithium), Be (beryllium), Mg (magnesium), Ca (calcium), Sr (strontium), Ba (barium), Al (aluminum), and Ga (gallium).

[0039] In other words, element A includes one or more alkali metal elements selected from K, Rb, and Cs, and may further include one or more selected from Na, Tl, In, Li, Be, Mg, Ca, Sr, Ba, Al, and Ga as needed. (1-3-2) Regarding the crystal structure, the tungsten bronze contained in the second layer 13, for example as described in the general formula above, contains element A and oxygen vacancies, thereby generating a sufficient amount of free electrons and imparting conductivity to the transparent conductive film. For this reason, the crystal structure of tungsten bronze is not particularly limited and can have one or more crystal structures selected from, for example, tetragonal, cubic, hexagonal, and pseudohexagonal. Pseudohexagonal refers to a structure that deviates from perfect hexagonal symmetry due to defects in the prism planes or bottom planes of the hexagonal crystal. Also, tungsten bronze may contain amorphous parts.

[0040] The second layer 13 is directly laminated on the first layer 12, and at least a portion of the first layer 12 may be epitaxially bonded to the tungsten oxide contained in the second layer 13.

[0041] In this specification, epitaxial bonding means that the difference in lattice constants between the bonded layers or thin films is sufficiently small. For example, if the difference between the lattice constant of the material in the bonded first layer 12 and the lattice constant of the material in the bonded second layer 13 is within 20% of the lattice constant of the material in the second layer 13, then the first layer 12 and the second layer 13 can be epitaxially bonded. Epitaxial bonding can be confirmed by observing a thin section of the bonded layers along the stacking direction using a transmission electron microscope.

[0042] Therefore, the first layer 12 and the second layer 13 may each contain materials with lattice constants within a predetermined range so that they can be epitaxially bonded. Specifically, for example, the first layer 12 may contain a material having a lattice constant that is 20% or less different from the lattice constant of the tungsten bronze contained in the second layer 13. The first layer 12 may consist only of materials having a lattice constant with the above difference of 20% or less. The lattice constant of the material contained in the first layer 12 may be 20% or less different from the {10-10} plane of the tungsten bronze when the second layer 13 contains hexagonal tungsten bronze.

[0043] By using a material such as a crystalline thin film that has epitaxial bonding properties with the tungsten bronze contained in the second layer 13 as the material for the first layer 12, at least a portion of the first layer 12 can be epitaxially bonded to the tungsten bronze-containing film of the second layer 13. As a result, the crystal orientation of the tungsten bronze-containing film of the second layer 13 increases, improving grain boundary bonding properties, reducing the disruption of conductive paths due to microcracks, etc., and improving the conductivity of the transparent conductive film of this embodiment.

[0044] The second layer 13 may contain, for example, Cs-HTB. Note that Cs-HTB refers to hexagonal tungsten bronze (hereinafter also referred to as "HTB") containing Cs (cesium) as an alkali metal element. An example of Cs-HTB is Cs ０．３２ WO ３ However, Cs ０．３２ WO ３ The lattice constants are a-axis: 7.4116 Å and c-axis: 7.5981 Å (ICDD83-1334). Generally, if the difference in lattice constants of compounds in adjacent layers is within 20%, epitaxial bonding is possible. For this reason, the second layer 13 is Cs ０．３２ WO ３ If it includes Cs ０．３２ WO ３ Based on the lattice constant, the crystals in the second layer 13 of Cs whose difference range is within 20% are those with a lattice constant of within 20%. ０．３２ WO ３It can form an epitaxial bond with the second layer 13. Specifically, a crystal having lattice constants such that the a-axis length is between 5.92928 Å and 8.89392 Å and the c-axis length is between 6.07848 Å and 9.11772 Å will have epitaxial properties with the second layer 13. Therefore, if the second layer 13 is Cs ０．３２ WO ３ If it includes the above, the first layer 12 preferably contains crystals having a lattice constant within the above range.

[0045] The first layer 12 contains tungsten oxide WO ３－ｘ Although it can have monoclinic or tetragonal crystal symmetry depending on the manufacturing method, it is approximately a nearly cubic crystal, and WO ６ It has a structure in which octahedrons are arranged in a cubic symmetry.

[0046] The second layer 13 may include an HTB thin film, but HTB is hexagonal tungsten bronze, WO ６ It has a structure in which octahedrons are arranged in hexagonal symmetry.

[0047] WO ３－ｘ The cubic plane ({100} plane) of ¹³¹ and the prism plane ({10-10} plane) of HTB have similar atomic arrangements, making epitaxial bonding easy. ３－ｘ The bonding configuration between the cubic surface and the prism surface of the HTB has actually been observed in the intergrowth tungsten bronze. Therefore, by including tungsten oxide in the first layer 12, at least a portion of the first layer 12 can be easily epitaxially bonded to the HTB thin film of the second layer 13.

[0048] Layer 12 is WO ３－ｘ The inclusion of tungsten oxide, as shown, facilitates epitaxial bonding between the cubic surface of the tungsten oxide in the first layer 12 and the prism surface of the HTB thin film in the second layer.

[0049] In the transparent conductive film of this embodiment, the prism surface ({10-10} surface) of the HTB thin film of the second layer 13 and the cubic surface ({100} surface) of the tungsten oxide of the first layer 12 may be epitaxially bonded.

[0050] The c-axis direction of the HTB thin film in the second layer 13 has higher free electron transport properties compared to the a-axis direction. Therefore, when the first layer 12 is epitaxially joined to the {10-10} plane, which is the prism surface of the HTB thin film in the second layer 13, the c-axis of the second layer 13 is oriented parallel to the film plane direction, which improves the free electron transport properties and further improves the conductivity of the transparent conductive film.

[0051] The HTB thin film contained in the second layer 13 may have an unoriented polycrystalline structure, but it is more preferable that it has a polycrystalline structure oriented to the {10-10} plane. That is, the diffraction peak intensity of the second layer 13 is increased due to the {10-10} plane of the HTB thin film, and the HTB thin film may have orientation to the prism plane. When the HTB thin film has a polycrystalline structure oriented to the {10-10} plane, free electrons are transported in the c-axis direction of the hexagonal crystal, which further improves the conductivity of the film.

[0052] HTB has the characteristic that its free electrons are bound in the a-axis and b-axis directions. Therefore, the electrical conductivity σ is higher for free electrons parallel to the c-axis (E / / c) than for free electrons perpendicular to the c-axis (E⊥c). For example, K ０．５ WO ３ Then σ / / = 12.7 [×10 ５ For S / m, σ⊥ = 4.0 [×10 ５ A value of S / m has been reported. Also, Cs ０．３ WO ３ Then σ / / = 14.4 [×10 ５ For S / m, σ⊥ = 5.4 [×10 ５ A value of S / m has been reported. σ / / represents the electrical conductivity parallel to the c-axis, and σ⊥ represents the electrical conductivity perpendicular to the c-axis.

[0053] Therefore, by orienting the HTB thin film contained in the second layer 13 in the {10-10} plane, conductive paths of crystal grains are formed in the direction of high electrical conductivity, thereby increasing conductivity compared to the case where the grains are randomly oriented. (1-3-3) Regarding the lattice constant, the lattice constant of the HTB contained in the second layer 13 is not particularly limited, but it is preferable that the lattice constant of the hexagonal c axis is 7.54 Å or less in the general formula for HTB described above when element A is K. When element A is Rb, it is preferable that the lattice constant of the hexagonal c axis is 7.58 Å or less. When element A is Cs, it is preferable that the lattice constant of the hexagonal c axis is 7.64 Å or less. In particular, it is more preferable that the lattice constant of the hexagonal c axis is 7.49 Å or more and 7.54 Å or less when element A is K. When element A is Rb, it is more preferable that the lattice constant of the hexagonal c axis is 7.51 Å or more and 7.58 Å or less. When element A is Cs, it is more preferable that the lattice constant of the hexagonal c axis be 7.56 Å or more and 7.64 Å or less. (1-3-4) Regarding film thickness, the average film thickness T13 of the second layer 13 is not particularly limited, but for example, the average film thickness T13 of the second layer 13 may be 5 nm or more and 1200 nm or less, 10 nm or more and 1200 nm or less, or 30 nm or more and 600 nm or less.

[0054] By setting the average film thickness T13 of the second layer 13 to 5 nm or more, the electrical resistance of the transparent conductive film 10 can be reduced, and a highly conductive transparent conductive film can be provided.

[0055] Furthermore, by setting the average film thickness T12 of the second layer 13 to 1200 nm or less, coloration of the second layer 13 and the transparent conductive film 10 can be suppressed, and visible light transmittance can be improved. By setting the average film thickness T12 of the second layer 13 to 1200 nm or less, the time required to form the second layer 13 can be shortened, and the productivity of manufacturing the transparent conductive film 10 can be increased. (1-4) Third layer (1-4-1) Composition of the third layer The transparent conductive film 10 of this embodiment may further have a third layer 14 laminated on the second layer 13.

[0056] The third layer 14 may be directly laminated on the second layer 13, or there may be any layer between the second layer 13 and the third layer 14.

[0057] Since the transparent conductive film 10 has the third layer 14, the transparent conductive film 10 can be protected from the outside world and prevented from being damaged or the like. Further, depending on the use of the transparent conductive film 10, the third layer 14 may have a function of adjusting the refractive index and improving optical properties such as visible light transmittance and reflectance in the infrared region.

[0058] Also, since the transparent conductive film 10 has the third layer 14, when performing heat treatment in the manufacturing process of the transparent conductive film 10, the diffusion of oxygen into the first layer 12 and the second layer 13 can be controlled. Therefore, the heat treatment can also be performed in an oxidizing atmosphere such as an air atmosphere. And even when the heat treatment is performed in an oxidizing atmosphere such as an air atmosphere, the degree of oxidation of tungsten bronze in the second layer 13 can be kept within an appropriate range, so that the haze and resistance value of the transparent conductive film 10 can be lowered.

[0059] The material contained in the third layer 14 is not particularly limited and can be selected according to the use of the transparent conductive film 10 and the optical properties required for the transparent conductive film 10. The third layer 14 is, for example, SiO ２ , TiO ２ , WO ３ , Nb ２ O ５ , Al ２ O ３ , ZrO ２ , Ta ２ O ５ , SnO ２ , Si ３ N ４ , LaB ６ , TiN, MgF ２ , HfO ２ , SiO ｘ N ｙ and contains one or more selected from the group of compounds. The third layer 14 is, for example, SiO ２ , TiO ２ , WO ３ , Nb ２ O ５ , Al ２ O ３ , ZrO ２ , Ta ２ O ５ , SnO ２ , Si ３ N ４LaB ６ It may also contain one or more compounds selected from the TiN compound group. For example, SiO contained in the third layer 14 ２ , TiO ２ WO ３ Nb ２ O ５ Al ２ O ３ , ZrO ２ Ta ２ O ５ , SnO ２ Si ３ N ４ LaB ６ TiN, MgF ２ , HfO ２ SiO ｘ N ｙ One or more compounds selected from the group of compounds may be included in the third layer 14 as a membrane containing these compounds.

[0060] For example, SiO ２ Yes, Nb ２ O ５ Because these materials have high transparency and high dielectric constant, it is preferable to use the transparent conductive film 10 as the material for the third layer 14 when using it in optical devices, displays, electronic devices, etc. For example, ZrO ２ Yes, Si ３ N ４ Al ２ O ３ For example, it is preferable to use the transparent conductive film 10 as the material for the third layer 14 when it is used in a device that requires mechanical strength and heat resistance. ２ Yes, LaB ６ It is preferable to use the transparent conductive film 10 as the material for the third layer 14 when it is used in applications where transparency, chemical stability, and high conductivity are required. There may be multiple third layers. (1-4-2) Regarding film thickness, the average film thickness T14 of the third layer 14 is not particularly limited, but for example, the average film thickness T14 of the third layer 14 may be 5 nm or more and 1200 nm or less, 10 nm or more and 1200 nm or less, or 30 nm or more and 600 nm or less.

[0061] By setting the average film thickness T14 of the third layer 14 to 5 nm or more, the transparent conductive film 10 can be particularly protected, resulting in a transparent conductive film with particularly excellent durability.

[0062] Furthermore, by setting the average film thickness T14 of the third layer 14 to 1200 nm or less, the time required to form the third layer 14 can be shortened, thereby increasing the productivity of the manufacturing of the transparent conductive film 10. (1-5) Underlying layer Figure 2 shows another example of the configuration of this embodiment, a transparent conductive film 20. As shown in Figure 2, the transparent conductive film of this embodiment may have an underlying layer 15 between the glass substrate 11 and the second layer 13.

[0063] Figure 2 shows an example in which the underlayer 15 is placed between the glass substrate 11 and the first layer 12, but the underlayer 15 may also be placed between the first layer 12 and the second layer 13.

[0064] Substrate 15 is made of general formula SiO ａ N ｂ It may contain one or more selected from silicon oxynitride represented by and aluminum oxide. The general formula SiO contained in the base layer 15 ａ N ｂ One or more compounds selected from silicon oxynitride and aluminum oxide, represented by , may be included in the substrate layer 15 as a film containing these compounds. (1-5-1) Composition of the substrate As explained in "(1-2) First layer", the glass used in the glass substrate contains additives. According to the inventors' research of the present invention, elements such as additives contained in the glass mainly used in the glass substrate, such as Group 1 elements such as alkali metals and Group 2 elements such as alkaline earth metals, react with tungsten bronze to produce a different phase.

[0065] Therefore, the transparent conductive film 10 of this embodiment has a first layer 12, which prevents elements such as additives contained in the glass from reaching the second layer 13 from the glass substrate 11. Furthermore, by having an underlayer 15, as in the transparent conductive film 20 of this embodiment, the amount of elements such as additives contained in the glass from reaching the second layer 13 from the glass substrate 11 can be further reduced. As a result, the presence of the underlayer 15 in the transparent conductive film 20 particularly prevents the formation of a different phase in the second layer 13 and increases the haze of the transparent conductive film.

[0066] Silicon oxynitride and aluminum oxide have the function of preventing components in the glass used in the glass substrate 11 from migrating to the second layer 13.

[0067] The general formula for silicon oxynitride is SiO ａ N ｂ In the expression, it is preferable that a and b satisfy 0 ≤ a ≤ 2 and 0 ≤ b ≤ 1.33. (2) Physical properties, etc. The physical properties of the transparent conductive film of this embodiment are not particularly limited, but it is preferable that they satisfy the characteristics described below, for example. (2-1) Haze The haze of the transparent conductive film of this embodiment is preferably 6.0% or less, and more preferably 0.1% or more and 6.0% or less.

[0068] By reducing the haze of the transparent conductive film of this embodiment to 6.0% or less, particularly clear transparency can be obtained, thereby improving visibility when used in openings such as window materials.

[0069] By setting the haze of the transparent conductive film of this embodiment to 0.1% or more, the productivity of the transparent conductive film can be increased. (2-2) Visible light transmittance The visible light transmittance of the transparent conductive film of this embodiment is preferably 20% or more and 90% or less, and more preferably 50% or more and 90% or less.

[0070] By setting the visible light transmittance of the transparent conductive film of this embodiment to 20% or more, visibility through the transparent conductive film of this embodiment can be improved when used in openings such as window materials. Furthermore, by setting the visible light transmittance of the transparent conductive film of this embodiment to 90% or less, the first layer 12, the second layer 13, and the third layer 14 can be made to a sufficient thickness, thereby particularly improving the heat shielding ability and durability of the transparent conductive film of this embodiment. (2-3) Solar radiation transmittance The solar radiation transmittance of the transparent conductive film of this embodiment is preferably 50% or less, and more preferably 10% or more and 50% or less.

[0071] By setting the solar transmittance of the transparent conductive film of this embodiment to 50% or less, the temperature rise on the indoor side can be sufficiently reduced when used in openings such as window materials. By setting the solar transmittance of this embodiment to 10% or more, the productivity of the transparent conductive film can be increased. (2-4) Electrical characteristics The resistivity of the transparent conductive film 10 of this embodiment is 1.01 × 10 －２ It is preferable that the ratio be less than or equal to Ωcm, and 1.01 × 10 －４ Ω・cm or more 1.01×10 －３ It is more preferable that the value be less than or equal to Ω·cm.

[0072] The transparent conductive film of this embodiment may also have a third layer, but the third layer is provided to protect the first and second layers, and can be partially removed by etching or other means as needed. Therefore, the electrical properties of the transparent conductive film of this embodiment can be evaluated based on the first and second layers excluding the third layer, and the resistivity of the first and second layers is 1.01 × 10⁻⁶. －２ A transparent conductive film can be said to have excellent conductivity if the conductivity is Ωcm or less. [Method for manufacturing a transparent conductive film] Next, an example of the configuration for manufacturing a transparent conductive film according to this embodiment will be described. According to the method for manufacturing a transparent conductive film of this embodiment, a transparent conductive film according to one aspect of the present disclosure can be manufactured. For this reason, some explanations of matters already described will be omitted. Note that the method for manufacturing a transparent conductive film according to one aspect of the present disclosure is not limited to the following method for manufacturing a transparent conductive film.

[0073] The method for manufacturing a transparent conductive film according to this embodiment includes a first layer deposition step, a second layer deposition step, and a third layer deposition step, and may include a deposition step in which a laminate in which the first layer, the second layer, and the third layer are laminated on a glass substrate, and a heat treatment step in which the laminate is heat treated.

[0074] Then, in the first film formation process, the general formula WO ３－ｘ A first layer containing tungsten oxide represented by (0 ≤ x ≤ 0.28) can be formed.

[0075] In the second layer deposition process, a second layer containing tungsten bronze can be deposited on the first layer.

[0076] In the third layer deposition process, SiO is deposited on the second layer. ２ , TiO ２ WO ３ Nb ２ O ５ Al ２ O ３ , ZrO ２ Ta ２ O ５ , SnO ２ Si ３ N ４ LaB ６ TiN, MgF ２ , HfO ２ SiO ｘ N ｙ A third layer containing one or more compounds selected from the group of compounds can be formed.

[0077] In the heat treatment process, the laminate obtained in the film formation process can be heat-treated in an oxygen-containing atmosphere.

[0078] The manufacturing process for the transparent conductive film of this embodiment may include, for example, a first layer deposition step S1, a second layer deposition step S2, a third layer deposition step S3, and a heat treatment step S4, as shown in the flow diagram 30 in Figure 3. However, if the desired transparent conductive film can be formed by omitting any of the steps, it is not necessary to go through all of the above steps.

[0079] The following describes each process. (1) Film deposition process In the film deposition process, raw material particles can be attached to the substrate by using, for example, a physical or chemical film deposition method to form a thin film. In the film deposition process, the first, second, and third layers can be deposited using one or more methods selected from, for example, vacuum deposition, sputtering, ion plating, ion beam sputtering, pulsed laser deposition (PLD), and chemical vapor deposition (CVD).

[0080] As for the sputtering method, one or more methods selected from high-frequency sputtering, pulsed sputtering, dual magnetron sputtering, etc., may be used. The materials contained in the first layer 12, the second layer 13, and the third layer 14 have already been described, so the explanation will be omitted. Each layer can be formed by selecting raw materials so as to form a layer with the desired composition according to the film formation method. (1-1) First layer film formation process The first layer film formation process will be described below.

[0081] In the first layer deposition process, the first layer can be deposited on the glass substrate. Since the glass substrate has already been explained, its explanation will be omitted here.

[0082] In the first layer deposition process, the substrate temperature during deposition is not particularly limited, and the process may be carried out at room temperature, i.e., without heating. However, depending on the properties required for the first layer or the transparent conductive film, the substrate may be heated during the first layer deposition process. For example, if the substrate is heated and sputtering deposition is performed, the first layer will be formed on the substrate while crystal growth occurs. This makes it possible to obtain a first layer film (e.g., a thin film) with uniform crystal orientation. When heating the substrate during the first layer deposition process, the substrate temperature is not particularly limited, and the substrate temperature can be selected according to the composition of the first layer to be deposited, for example.

[0083] In the first layer deposition step, a first layer containing tungsten oxide can be deposited. In the first layer deposition step, a first layer containing a film (e.g., a thin film) containing tungsten oxide may be deposited. (1-2) Second layer deposition step The second layer deposition step will be described below.

[0084] The second layer deposition process can be carried out using the first layer deposited on the glass substrate as the substrate.

[0085] In the second layer deposition process, the substrate temperature during deposition is not particularly limited; for example, the second layer deposition process may be carried out at room temperature, i.e., without heating. However, depending on the characteristics required for the second layer or the transparent conductive film, the substrate may be heated during the second layer deposition process.

[0086] In the second layer deposition process, a second layer containing tungsten bronze can be deposited. In the second layer deposition process, a second layer containing a film (e.g., a thin film) containing tungsten bronze may be deposited. (1-3) Third layer deposition process The third layer deposition process will now be described.

[0087] The third layer deposition process can be carried out using the second layer deposited on the glass substrate as the substrate.

[0088] In the third layer deposition process, the substrate temperature during deposition is not particularly limited; for example, the third layer deposition process may be carried out at room temperature, i.e., without heating. However, depending on the properties required for the third layer or the transparent conductive film, the substrate may be heated during the third layer deposition process.

[0089] In the third layer deposition process, SiO ２ , TiO ２ WO ３ Nb ２ O ５ Al ２ O ３ , ZrO ２ Ta ２ O ５ , SnO ２ Si ３ N ４ LaB ６ TiN, MgF ２ , HfO ２ SiO ｘ N ｙ A third layer containing one or more compounds selected from the group of compounds can be formed. In the third layer formation process, SiO ２ , TiO ２ WO ３ Nb ２ O ５ Al ２ O３ , ZrO ２ Ta ２ O ５ , SnO ２ Si ３ N ４ LaB ６ A third layer containing one or more compounds selected from the TiN compound group may be formed. In the third layer formation step, a third layer containing a film (e.g., a thin film) containing one or more compounds selected from the above compound group may be formed. (2) Heat treatment step In the heat treatment step, the laminate formed by stacking the first layer 12, second layer 13, and third layer 14 formed in the first layer formation step, second layer formation step, and third layer formation step can be heat treated.

[0090] The atmosphere in the heat treatment process is not particularly limited, but may be selected from, for example, a vacuum atmosphere, an inert gas atmosphere, a reducing gas atmosphere such as hydrogen, and an oxidizing gas atmosphere such as oxygen. However, according to the method for manufacturing a transparent conductive film of this embodiment, the heat treatment process can be carried out after the formation of the third layer 14, and the diffusion of oxygen to the first layer 12 and the second layer 13 can be controlled by the third layer 14. For this reason, the atmosphere in the heat treatment process can be an oxygen-containing atmosphere. The heat treatment process may also be carried out in an atmospheric atmosphere that can be easily formed and controlled. In the heat treatment process, for example, the heat treatment can be carried out at a heat treatment temperature of 300°C to 1000°C.

[0091] The heat treatment temperature in the heat treatment process is not particularly limited, but considering the heat resistance of the glass substrate, it is preferably 1000°C or lower, and more preferably 650°C or lower. In particular, the material contained in the first layer 12 may be heat-treated near the phase transition temperature of the desired crystal structure in order to achieve the desired crystal structure.

[0092] The heating rate and heat treatment time in the heat treatment process are not particularly limited, but in order to grow crystals in the first layer 12, it is preferable that the heating rate be 1°C / min or more, and further, after heating to the heat treatment temperature, it is preferable to hold it at the heat treatment temperature for 30 minutes or more. (3) The method for manufacturing the transparent conductive film of this embodiment may also include a base layer formation step as needed.

[0093] The underlayer deposition process can be carried out using the same procedure as the first layer deposition process, except that the material used is appropriate to the material of the underlayer to be deposited.

[0094] The present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto. 1. Evaluation Method (1) X-ray Diffraction Pattern The X-ray diffraction pattern (XRD pattern) of the obtained transparent conductive film was measured using Cu-Kα rays with a D2PHASER X-ray diffractometer from BRUKER AXS. (2) Visible Light Transmittance and Solar Radiation Transmittance In measuring the optical properties of the obtained transparent conductive film, the transmittance and 8° incident diffuse reflectance were measured using a spectrophotometer V-670 (manufactured by JASCO Corp.), and the transmittance spectrum and reflectance spectrum were obtained. Then, using the spectral data of transmittance and reflectance, the visible light transmittance (VLT) and solar radiation transmittance (ST) at wavelengths of 300 nm to 2500 nm were determined in accordance with JIS R 3106 (2019). (3) Haze The haze value was measured using a haze meter (HM-150N manufactured by Murakami Color Technology Laboratory Co., Ltd.) and calculated based on JIS K 7136 (2000). (4) Average film thickness The average film thickness was measured at a total of 5 locations at 1 μm intervals along the surface of the glass substrate in an SEM image taken at any one location on the cross-section of the sample, and the arithmetic mean was taken. (5) Surface resistivity and resistivity The surface resistivity of the obtained transparent conductive film structure was measured using Loresta-GXII manufactured by Nitto Seiko Analytic Co., Ltd., and the resistivity was determined by incorporating the shape factor. 2. Manufacturing conditions and evaluation results of the transparent conductive film [Example 1] In Example 1, as shown in Figure 2, a transparent conductive film was fabricated by laminating a base layer 15, a first layer 12, a second layer 13, and a third layer 14 in order on a glass substrate 11, and evaluated. (1) Fabrication of transparent conductive film (1-1) Fabrication of tungsten oxide target for first layer deposition Tungsten oxide powder was placed in a discharge plasma sintering apparatus (NJS Corporation) under conditions of a vacuum atmosphere, temperature of 870°C, and pressure of 50 MPa to produce a tungsten oxide sintered body. This sintered body was machined to a diameter of 20 mm and a thickness of 4 mm to produce a tungsten oxide target.(1-2) Preparation of a cesium tungsten oxide target for second layer deposition A cesium tungsten oxide powder (YM-01, manufactured by Sumitomo Metal Mining Co., Ltd.) with a Cs / W atomic ratio of 0.33 was introduced into a discharge plasma sintering apparatus (NJS Corporation) under vacuum conditions, a temperature of 870°C, and a pressure of 50 MPa to produce a cesium tungsten oxide sintered body. Chemical analysis of the sintered body composition revealed that the Cs / W ratio, which is the ratio of the amount of substance of Cs to W, was 0.32. This oxide sintered body was machined to a diameter of 20 mm and a thickness of 4 mm to produce a CsWO target.

[0095] Except for the fact that the underlayer deposition process was further carried out using the above target, a transparent conductive film was deposited according to the flow diagram 30 shown in Figure 3. (1-3) Underlayer deposition process

[0096] Specifically, in the underlayer deposition process, an aluminum oxide target was used to deposit the underlayer 15.

[0097] The underlayer film formation process was carried out under the following conditions and procedures.

[0098] An aluminum oxide target was placed inside the vacuum chamber of a pulsed laser deposition system (Pascal PAC-LMBE). The maximum vacuum pressure was 1 × 10⁻¹⁶. －５ The pressure was kept below Pa, and during film formation, oxygen gas was introduced into the vacuum chamber to a gas pressure of 0.5 Pa, and the underlayer 15 was formed on a soda glass substrate.

[0099] The irradiation laser used was a KrF laser (wavelength 248 nm, pulse width 25 ns), with a laser power of 150 mJ, a laser frequency of 4 Hz, and a laser irradiation time of 10 minutes, under room temperature film deposition conditions (no substrate heating).

[0100] Under the above conditions, a continuous aluminum oxide film was deposited on the glass substrate in the underlayer deposition process. (1-4) First layer deposition process The tungsten oxide target was placed in the vacuum chamber of the pulsed laser deposition system (Pascal PAC-LMBE). The maximum vacuum pressure was 1 × 10⁻⁶ －５The pressure was kept below Pa, and during film formation, oxygen gas was introduced into the vacuum chamber to a gas pressure of 6.8 Pa to form the first layer 12.

[0101] A KrF laser (wavelength 248 nm, pulse width 25 ns) was used for irradiation, with a laser power of 150 mJ, a laser frequency of 4 Hz, and a laser irradiation time of 10 minutes. The heater temperature for heating the substrate was set to 400°C, and in the underlayer deposition process, a first layer 12 was deposited on top of the aluminum oxide film, which was the underlayer deposited on the glass substrate.

[0102] Under the above conditions, in the first layer deposition process, a continuous film of tungsten oxide was deposited on the underlying layer. (1-5) In the second layer deposition process, the target used was replaced with a cesium tungsten oxide target. The maximum vacuum pressure was 1 × 10⁻⁶. －５ The vacuum pressure was kept below Pa, and during film deposition, oxygen gas was introduced into the vacuum chamber to achieve a gas pressure of 6.8 Pa for the deposition of the second layer. During film deposition, a KrF laser (wavelength 248 nm, pulse width 25 ns) was used as the irradiation laser, with a laser power of 150 mJ, a laser frequency of 4 Hz, and a laser irradiation time of 10 minutes, under room temperature deposition conditions (no substrate heating). In the first layer deposition process, a continuous film of cesium tungsten oxide was deposited on top of the tungsten oxide film, which was the first layer deposited on the glass substrate. (1-6) In the third layer deposition process, the target used was replaced with an aluminum oxide target. The maximum vacuum pressure was 1 × 10⁻⁶ －５The pressure was kept below Pa, and during film deposition, oxygen gas was introduced into the vacuum chamber to a gas pressure of 0.5 Pa to deposit the third layer. During film deposition, a KrF laser (wavelength 248 nm, pulse width 25 ns) was used as the irradiation laser, with a laser power of 150 mJ, a laser frequency of 4 Hz, and a laser irradiation time of 10 minutes. The third layer 14 was deposited under conditions where the substrate heater temperature reached 400°C. In the second layer deposition process, a continuous aluminum oxide film was deposited on top of the cesium tungsten oxide film, which was the second layer deposited on the glass substrate. (1-7) Heat treatment process After the completion of the third layer deposition process, the introduction of oxygen gas was stopped, and under an atmospheric environment, the substrate heater inside the vacuum chamber was heated to 500°C, and after holding the temperature for 30 minutes, a heat treatment process was carried out, followed by slow cooling to room temperature (heat treatment process). (2) Evaluation results The transparent conductive film obtained in Example 1 was evaluated according to the procedure described in "1. Evaluation method". (2-1) X-ray diffraction pattern The X-ray diffraction pattern of the transparent conductive film of Example 2, which was deposited using the measurement method described in "(1) X-ray diffraction pattern", was measured. The compounds identified from the X-ray diffraction pattern are listed in the "Substances detected by XRD" column of Table 1.

[0103] As shown in Table 1, the compounds contained in the transparent conductive film include tungsten oxide (o-WO) contained in the first layer 12. ３ ) and the Cs contained in the second layer 13 ０．３３ WO ３ And was identified. Furthermore, Na ０．０２ WO ２．８ Na was observed. ０．０２ WO ２．８ Na that has moved from the glass substrate 11 is in the WO of the first layer 12. ３ It is thought to have been produced by a reaction with Na. ０．０２ WO ２．８ WO ３ Since it is a tungsten bronze compound of the same crystalline system, it does not increase the haze of the transparent conductive film 10, and is instead thought to have the effect of improving conductivity and heat shielding properties.

[0104] Al contained in the base layer 15 and the third layer 14 ２ O３ Regarding this, no peak was observed because it is amorphous. (2-2) Optical properties As shown in Table 1, the visible light transmittance was 60.42% and the solar transmittance was 36.21%, confirming that it has excellent transmittance in the visible light region and also excellent heat shielding properties.

[0105] Furthermore, it was confirmed that the haze was also extremely low at 1.1%. (2-3) Surface resistivity and resistivity The surface resistivity of the transparent conductive film obtained in Example 1 was 5.82 × 10 (Ω / □), and the resistivity was 8.32 × 10 from the film thickness and sample shape. －４ It was (Ω・cm).

[0106] From the above results, it was confirmed that the transparent conductive film of Example 1 is a useful material with low haze and conductivity. (2-4) Transmission electron microscopy observation A sample thinned along the layer stacking direction was observed using a transmission electron microscope. As a result, it was clearly confirmed from the atomic arrangement observed by locally magnifying the atomic image in accordance with the

[0001] orientation of the second layer that at least a part of the first layer and the HTB thin film of the second layer are epitaxially bonded. [Example 2] In Example 2, as shown in Figure 1, a transparent conductive film was made by sequentially stacking the first layer 12, the second layer 13, and the third layer 14 on a glass substrate 11 and evaluated. (1) Preparation of the transparent conductive film The transparent conductive film was made under the same conditions as in Example 1, except that the underlayer deposition process was not performed. (2) Evaluation results The transparent conductive film obtained in Example 1 was evaluated according to the procedure described in "1. Evaluation method". (2-1) X-ray diffraction pattern The transparent conductive film of Example 1, which was deposited with an X-ray diffraction pattern, was measured using the measurement method described in "(1) X-ray diffraction pattern". The compounds identified from the X-ray diffraction pattern are listed in the "Substances detected by XRD" column of Table 1.

[0107] As shown in Table 1, the compounds contained in the transparent conductive film include tungsten oxide (o-WO) contained in the first layer 12. ３ ) and the Cs contained in the second layer 13 ０．３３ WO ３ And was identified. Furthermore, Na ０．０２ WO ２．８ Na was observed.０．０２ WO ２．８ Na that has moved from the glass substrate 11 is in the WO of the first layer 12. ３ It is thought to have been produced by a reaction with Na. ０．０２ WO ２．８ WO ３ Since the structure involves Na invading the gaps between crystals and does not cause distortion to the surrounding matrix, it does not increase the haze of the transparent conductive film 10, and is instead thought to have the effect of improving the conductivity and heat shielding properties. (2-2) Optical properties As shown in Table 1, the visible light transmittance is 57.75% and the solar transmittance is 30.12%, confirming that it has excellent transmittance in the visible light region and also excellent heat shielding properties.

[0108] Furthermore, it was confirmed that the haze was also extremely low at 1.5%. (2-3) Surface resistivity and resistivity The surface resistivity of the transparent conductive film obtained in Example 2 was 1.23 × 10⁻⁶ ３ (Ω / □) and, given the film thickness and sample shape, the resistivity is 0.97 × 10⁻⁶ －３ It was (Ω・cm).

[0109] From the above results, it was confirmed that the transparent conductive film of Example 2 is a useful material with low haze and conductivity. (2-4) Transmission electron microscopy observation A sample thinned along the layer stacking direction was observed using a transmission electron microscope. As a result, it was clearly confirmed from the atomic arrangement observed by locally magnifying the atomic image in line with the

[0001] orientation of the second layer that at least a part of the first layer and the HTB thin film of the second layer are epitaxially bonded. [Comparative Example 1] (1) Fabrication of transparent conductive film In Comparative Example 1, the third layer deposition process was not performed, and the heat treatment process was performed after the second layer deposition process. Except for the above, the transparent conductive film was manufactured under the same conditions and procedures as in Example 1. (2) Evaluation results The transparent conductive film obtained in Comparative Example 1 was evaluated according to the procedure described in "1. Evaluation method". (2-1) X-ray diffraction pattern The X-ray diffraction pattern was measured for the transparent conductive film of Comparative Example 1 that had been deposited, using the measurement method described in "(1) X-ray diffraction pattern". Compounds identified from the X-ray diffraction pattern are listed in the "Substances Detected by XRD" column of Table 1.

[0110] As shown in Table 1, the compounds contained in the transparent conductive film include o-WO contained in the first layer. ３ Besides Na ０．０２ WO ２．８ and Na ２ W ６ O １９ It was identified.

[0111] The components contained in the first and second layers react with the components contained in the glass substrate and oxygen in the atmosphere, resulting in Na ０．０２ WO ２．８ and Na ２ W ６ O １９ It is thought that this was generated. (2-2) Optical properties As shown in Table 1, although the visible light transmittance was 89.32%, it was confirmed that the solar radiation transmittance was 86.77%. In other words, it was confirmed that the transparent conductive film of Comparative Example 1 had excellent transmittance in the visible light region, but poor heat shielding properties. It was also confirmed that the haze was high at 7.2%. The reason for the high haze is that the transparent conductive film of Comparative Example 1 does not have a third layer 14, so during heat treatment, the composite tungsten oxide contained in the second layer 13 contains Na with a different crystal structure ２ W ６ O １９ This is thought to be because it was generated. (2-3) Surface resistivity, specific resistivity The surface resistivity of the transparent conductive film obtained in Comparative Example 1 was 6.45 × 10 ９ (Ω / □) and, given the film thickness and sample shape, the resistivity is 9.35 × 10⁻⁶ ４ It was large (Ω・cm).

[0112] From these results, it was confirmed that the transparent conductive film of Comparative Example 1 was a material with high haze and poor conductivity.

[0113]

[0114] Examples of embodiments of the present disclosure are as follows:

[0115] <1> The material comprises a glass substrate, a first layer, a second layer, and a third layer, wherein the first layer is of the general formula WO ３－ｘ The second layer contains tungsten oxide represented by (0 ≤ x ≤ 0.28), the third layer contains tungsten bronze, and the third layer contains SiO２ , TiO ２ WO ３ Nb ２ O ５ Al ２ O ３ , ZrO ２ Ta ２ O ５ , SnO ２ Si ３ N ４ LaB ６ A transparent conductive film comprising one or more compounds selected from the TiN group, arranged in the order of the first layer, second layer, and third layer from a position close to the glass substrate.

[0116] <2> The transparent conductive film according to <1>, wherein the average film thickness of the first layer is 5 nm or more and 1200 nm or less, the average film thickness of the second layer is 5 nm or more and 1200 nm or less, and the average film thickness of the third layer is 5 nm or more and 1200 nm or less.

[0117] <3> The glass substrate and the second layer have an underlayer, the underlayer being composed of a general formula SiO ａ N ｂ A transparent conductive film according to <1> or <2>, comprising silicon oxynitride represented by and one or more selected from aluminum oxide.

[0118] <4> A transparent conductive film according to any of <1> to <3>, wherein the haze is 0.1% or more and 6.0% or less.

[0119] <5> A transparent conductive film according to any of <1> to <4>, wherein the visible light transmittance is 20% or more and 90% or less.

[0120] <6> A transparent conductive film according to any of <1> to <5>, wherein the solar transmittance is 50% or less.

[0121] This application claims priority based on Japanese Patent Application No. 2024-184471, filed with the Japan Patent Office on 18 October 2024, and the entire contents of Japanese Patent Application No. 2024-184471 are incorporated herein by reference.

[0122] 10 Transparent conductive film 20 Transparent conductive film 11 Glass substrate 12 First layer T12 Average film thickness 13 Second layer T13 Average film thickness 14 Third layer 15 Underlayer 30 Flowchart S1 First layer deposition process S2 Second layer deposition process S3 Third layer deposition process S4 Heat treatment process

Claims

1. A transparent conductive film having a glass substrate, a first layer, a second layer, and a third layer, wherein the first layer contains tungsten oxide represented by the general formula WO ３－ｘ (0 ≤ x ≤ 0.28), the second layer contains tungsten bronze, and the third layer contains SiO ２ , TiO ２ , WO ３ , Nb ２ O ５ , Al ２ O ３ , ZrO ２ , Ta ２ O ５ , SnO ２ , Si ３ N ４ , LaB ６ , TiN, and contains one or more selected from the group of compounds, and is arranged in the order of the first layer, the second layer, and the third layer from a position close to the glass substrate.

2. The transparent conductive film according to claim 1, wherein the average film thickness of the first layer is 5 nm or more and 1200 nm or less, the average film thickness of the second layer is 5 nm or more and 1200 nm or less, and the average film thickness of the third layer is 5 nm or more and 1200 nm or less.

3. The glass substrate and the second layer have an underlayer, the underlayer being of the general formula SiO ａ N ｂ A transparent conductive film according to claim 1 or claim 2, comprising one or more selected from silicon oxynitride represented by and aluminum oxide.

4. A transparent conductive film according to any one of claims 1 to 3, wherein the haze is 0.1% or more and 6.0% or less.

5. A transparent conductive film according to any one of claims 1 to 4, wherein the visible light transmittance is 20% or more and 90% or less.

6. A transparent conductive film according to any one of claims 1 to 5, wherein the solar transmittance is 50% or less.

Images