JP7240513B2 - transparent conductive film - Google Patents

Description

The present invention relates to transparent conductive films.

Conventionally, there has been known a transparent conductive film having a transparent base film and a transparent conductive layer (light-transmitting conductive layer) in order in the thickness direction. A light-transmissive conductive layer is used as a conductive film for patterning transparent electrodes in various devices such as liquid crystal displays, touch panels, and optical sensors. In the process of forming the light-transmissive conductive layer, for example, first, an amorphous film of a light-transmissive conductive material is formed on the substrate film by sputtering (film formation step). Next, the amorphous light-transmitting conductive layer on the substrate film is crystallized by heating (crystallization step). In the sputtering method in the film forming process, an inert gas such as argon is conventionally used as a sputtering gas for colliding with a target (film forming material supplying material) to eject atoms from the surface of the target. Techniques related to such transparent conductive films are described, for example, in Patent Document 1 below.

JP 2017-71850 A

From the viewpoint of production efficiency of the transparent conductive film, it is preferable that the rate of crystallization of the light-transmitting conductive layer by heating in the crystallization step is high.

However, the higher the rate of crystallization by heating, the more easily the conventional light-transmitting conductive layer crystallizes even under low-temperature (for example, room temperature) conditions. When a transparent conductive film having a light-transmitting conductive layer with a high crystallization rate is temporarily stored at room temperature, for example, crystallization may partially progress in the light-transmitting conductive layer. In the process of crystallizing such a light-transmitting conductive layer, strain occurs at the boundary between the portion where crystallization starts and progresses and the portion which has already crystallized during storage. This strain can cause cracks to form in the formed crystalline light-transmissive conductive layer. The occurrence of cracks in the light-transmissive conductive layer is not preferable from the viewpoint of the manufacturing yield of the transparent conductive film and the manufacturing yield of the device provided with the transparent conductive film. Therefore, the amorphous light-transmitting conductive layer is required to be able to be stored satisfactorily by suppressing crystallization when stored under low-temperature (for example, room temperature) conditions.

The present invention provides a transparent conductive film that achieves a high crystallization rate in a light-transmitting conductive layer and is suitable for ensuring good storage stability.

The present invention [1] comprises a transparent substrate and an amorphous light-transmitting conductive layer in this order in the thickness direction, wherein the light-transmitting conductive layer contains krypton and has a thickness of 40×10 ¹⁹ cm ⁻ A transparent conductive film having a carrier density of ³ or greater is included.

The present invention [2] includes the transparent conductive film according to [1] above, wherein the light-transmitting conductive layer contains an indium-containing conductive oxide.

The present invention [3] includes the transparent conductive film of the above [1] or [2], wherein the light-transmitting conductive layer has a thickness of 40 nm or more.

The present invention [4] is the transparent conductive film according to any one of [1] to [3] above, wherein the light-transmitting conductive layer has a Hall mobility of 18 cm ² /V·s or less. include.

The present invention [5] relates to the above [1] to [4], wherein the light-transmitting conductive layer has a resistivity of 2.2×10 ⁻⁴ Ω·cm or less after heat treatment at 130° C. for 1.5 hours. ] The transparent conductive film as described in any one of ] is included.

In the transparent conductive film of the present invention, the light-transmitting conductive layer contains krypton and has a carrier density of 40×10 ¹⁹ cm ^{−3 or} more, so that a high crystallization rate is achieved in the light-transmitting conductive layer. It is suitable for ensuring good storage stability together with

BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic diagram of one Embodiment of the transparent conductive film of this invention. 2 represents a method for manufacturing the transparent conductive film shown in FIG. 2A shows a step of preparing a resin film, FIG. 2B shows a step of forming a functional layer on the resin film, and FIG. 2C shows a step of forming a light-transmitting conductive layer on the functional layer. In the transparent conductive film shown in FIG. 1, the amorphous light-transmitting conductive layer is converted to a crystalline light-transmitting conductive layer. In the transparent conductive film shown in FIG. 1, it represents the case where the transparent conductive layer is patterned. 4 is a graph showing the relationship between the amount of oxygen introduced when forming a light-transmitting conductive layer by a sputtering method and the surface resistance of the formed light-transmitting conductive layer.

FIG. 1 is a schematic cross-sectional view of a transparent conductive film X, which is one embodiment of the transparent conductive film of the present invention. The transparent conductive film X includes a transparent substrate 10 and a light-transmissive conductive layer 20 in this order toward one side in the thickness direction D. As shown in FIG. The transparent conductive film X has a shape that spreads in a direction perpendicular to the thickness direction D (surface direction). The transparent conductive film X is one element provided in touch sensor devices, light control elements, photoelectric conversion elements, heat ray control members, antenna members, electromagnetic wave shield members, lighting devices, image display devices, and the like.

The transparent substrate 10 includes a resin film 11 and a functional layer 12 in this order toward one side in the thickness direction D in this embodiment. The transparent substrate 10 has a shape that spreads in a direction perpendicular to the thickness direction D (surface direction).

The resin film 11 is a flexible transparent resin film. Examples of materials for the resin film 11 include polyester resin, polyolefin resin, acrylic resin, polycarbonate resin, polyethersulfone resin, polyarylate resin, melamine resin, polyamide resin, polyimide resin, cellulose resin, and polystyrene resin. Polyester resins include, for example, polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate. Polyolefin resins include, for example, polyethylene, polypropylene, and cycloolefin polymers (COP). Examples of acrylic resins include polymethacrylate. As the material of the resin film 11, for example, from the viewpoint of transparency and strength, polyolefin resin is preferably used, and COP is more preferably used.

The surface of the resin film 11 on the side of the functional layer 12 may be subjected to a surface modification treatment. Surface modification treatments include, for example, corona treatment, plasma treatment, ozone treatment, primer treatment, glow treatment, and coupling agent treatment.

The thickness of the resin film 11 is preferably 1 μm or more, more preferably 10 μm or more, and even more preferably 30 μm or more. The thickness of the resin film 11 is preferably 300 μm or less, more preferably 200 μm or less, still more preferably 100 μm or less, and particularly preferably 75 μm or less. These configurations regarding the thickness of the resin film 11 are suitable for ensuring the handleability of the transparent conductive film X.

The total light transmittance (JIS K 7375-2008) of the resin film 11 is preferably 60% or higher, more preferably 80% or higher, and even more preferably 85% or higher. Such a configuration can be used when the transparent conductive film X is provided in a touch sensor device, a light control element, a photoelectric conversion element, a heat ray control member, an antenna member, an electromagnetic wave shield member, a lighting device, an image display device, or the like. It is suitable for ensuring the transparency required for the conductive film X. The total light transmittance of the resin film 11 is, for example, 100% or less.

The functional layer 12 is located on one surface of the resin film 11 in the thickness direction D in this embodiment. Further, in the present embodiment, the functional layer 12 is a hard coat layer for making the exposed surface (upper surface in FIG. 1) of the light-transmitting conductive layer 20 less likely to be scratched.

The hard coat layer is a cured product of a curable resin composition. Examples of resins contained in the curable resin composition include polyester resins, acrylic resins, urethane resins, amide resins, silicone resins, epoxy resins, and melamine resins. Moreover, examples of the curable resin composition include an ultraviolet curable resin composition and a thermosetting resin composition. As the curable resin composition, an ultraviolet curable resin composition is preferably used from the viewpoint of improving the production efficiency of the transparent conductive film X because it can be cured without heating to a high temperature. Specific examples of the UV-curable fat composition include compositions for forming a hard coat layer described in JP-A-2016-179686.

The surface of the functional layer 12 on the side of the light transmissive conductive layer 20 may be subjected to a surface modification treatment. Surface modification treatments include, for example, corona treatment, plasma treatment, ozone treatment, primer treatment, glow treatment, and coupling agent treatment.

The thickness of the functional layer 12 as a hard coat layer is preferably 0.1 μm or more, more preferably 0.5 μm or more, and even more preferably 1 μm or more. Such a configuration is suitable for exhibiting sufficient abrasion resistance in the light-transmitting conductive layer 20 . The thickness of the functional layer 12 as a hard coat layer is preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 3 μm or less from the viewpoint of ensuring the transparency of the functional layer 12 .

The thickness of the transparent substrate 10 is preferably 1 μm or more, more preferably 10 μm or more, even more preferably 15 μm or more, and particularly preferably 30 μm or more. The thickness of the transparent substrate 10 is preferably 310 μm or less, more preferably 210 μm or less, still more preferably 110 μm or less, and particularly preferably 80 μm or less. These configurations regarding the thickness of the transparent substrate 10 are suitable for ensuring the handleability of the transparent conductive film X.

The total light transmittance (JIS K 7375-2008) of the transparent substrate 10 is preferably 60% or higher, more preferably 80% or higher, and even more preferably 85% or higher. Such a configuration can be used when the transparent conductive film X is provided in a touch sensor device, a light control element, a photoelectric conversion element, a heat ray control member, an antenna member, an electromagnetic wave shield member, a lighting device, an image display device, or the like. It is suitable for ensuring the transparency required for the conductive film X. The total light transmittance of the transparent substrate 10 is, for example, 100% or less.

The light-transmissive conductive layer 20 is located on one surface of the transparent substrate 10 in the thickness direction D in this embodiment. The light-transmitting conductive layer 20 is an amorphous film having both light-transmitting properties and electrical conductivity. The amorphous light-transmitting conductive layer 20 is converted into a crystalline light-transmitting conductive layer (light-transmitting conductive layer 20' described later) by heating, thereby lowering the specific resistance.

The light-transmissive conductive layer 20 is a layer made of a light-transmissive conductive material. The light-transmitting conductive material contains, for example, a conductive oxide as a main component.

As the conductive oxide, for example, at least one metal selected from the group consisting of In, Sn, Zn, Ga, Sb, Ti, Si, Zr, Mg, Al, Au, Ag, Cu, Pd, and W Alternatively, metal oxides containing metalloids may be mentioned. Specifically, conductive oxides include indium-containing conductive oxides and antimony-containing conductive oxides. Indium-containing conductive oxides include, for example, indium tin composite oxide (ITO), indium zinc composite oxide (IZO), indium gallium composite oxide (IGO), and indium gallium zinc composite oxide (IGZO). be done. Antimony-containing conductive oxides include, for example, antimony-tin composite oxide (ATO). From the viewpoint of realizing high transparency and good conductivity, as the conductive oxide, an indium-containing conductive oxide is preferably used, and ITO is more preferably used. This ITO may contain metals or metalloids other than In and Sn in amounts less than the respective contents of In and Sn.

When ITO is used as the conductive oxide, the ratio of the tin oxide content to the total content of indium oxide (In ₂ O ₃ ) and tin oxide (SnO ₂ ) in the light-transmitting conductive layer 20 (tin oxide content ratio ) is preferably 1% by mass or more, more preferably 3% by mass or more, still more preferably 5% by mass or more, and particularly preferably 7% by mass or more. Such a configuration is suitable for ensuring durability of the light transmissive conductive layer 20 . From the viewpoint of obtaining the light-transmitting conductive layer 20 that is easily crystallized by heating, the tin oxide content is preferably 15% by mass or less, more preferably 13% by mass or less, and even more preferably 12% by mass or less. The above content of tin oxide is obtained from the XPS spectrum of the measurement object measured by X-ray Photoelectron Spectroscopy.

The tin oxide content in the light transmissive conductive layer 20 may be non-uniform in the thickness direction D. For example, the light-transmitting conductive layer 20 may include a first layer having a relatively high tin oxide content and a second layer having a relatively low tin oxide content, in this order from the transparent substrate 10 side. good. The tin oxide content in the first layer is preferably 5% by mass or more, more preferably 8% by mass or more. The tin oxide content in the first layer is preferably 15% by mass or less, more preferably 13% by mass or less. The tin oxide content in the second layer is preferably 0.5% by mass or more, more preferably 2% by mass or more. The tin oxide content in the second layer is preferably 8% by mass or less, more preferably 5% by mass or less. The ratio of the thickness of the first layer to the thickness of the light transmissive conductive layer 20 is preferably 50% or more, more preferably 60% or more, still more preferably 70% or more. Also, the ratio of the thickness of the second layer to the thickness of the light-transmitting conductive layer 20 is preferably 50% or less, more preferably 40% or less, and even more preferably 30% or less.

The light-transmitting conductive layer 20 contains krypton (Kr) as rare gas atoms. In the present embodiment, the rare gas atoms in the light-transmitting conductive layer 20 are derived from rare gas atoms used as a sputtering gas in a sputtering method, which will be described later. In this embodiment, the light transmissive conductive layer 20 is a film (sputtered film) formed by a sputtering method.

The light-transmitting conductive layer 20, which is a sputtered film formed by using Kr as a sputtering gas, has higher light transmission than the conventional light-transmitting conductive layer, which is a sputtered film formed by using Ar as a sputtering gas. suitable for realizing a high crystallization rate in the conductive layer. That is, the configuration in which the light-transmissive conductive layer 20 contains Kr is suitable for realizing a high crystallization rate in the light-transmissive conductive layer 20 . In addition, this configuration is suitable for suppressing crystallization of the amorphous light-transmissive conductive layer 20 under low-temperature (for example, room temperature) conditions, and is therefore suitable for ensuring good storage stability. The presence or absence of Kr in the light-transmitting conductive layer 20 is identified, for example, by fluorescent X-ray analysis, which will be described later with regard to Examples.

The content of Kr in the light-transmissive conductive layer 20 is, for example, 0.5 atomic % or less, preferably 0.3 atomic % or less, and more preferably 0.2 atomic % or less in the entire thickness direction D. be. Such a configuration is suitable for achieving good crystal growth and forming large crystal grains when the amorphous light-transmitting conductive layer 20 is crystallized by heating, and thus has low resistance and light-transmitting properties. Suitable for obtaining a conductive layer 20' (the larger the grains in the light-transmissive conductive layer 20', the lower the resistance of the light-transmissive conductive layer 20'). In addition, the content of Kr in the light-transmitting conductive layer 20 is, for example, 0.0001 atomic % or more in the entire thickness direction D.

The Kr content in the light transmissive conductive layer 20 may be non-uniform in the thickness direction D. For example, in the thickness direction D, the Kr content may gradually increase or decrease as the distance from the transparent substrate 10 increases. Alternatively, in the thickness direction D, a partial region in which the Kr content rate gradually increases with increasing distance from the transparent substrate 10 is located on the transparent substrate 10 side, and a partial region in which the Kr content rate gradually decreases with increasing distance from the transparent substrate 10. may be located on the side opposite to the transparent substrate 10 . Alternatively, in the thickness direction D, a partial region in which the Kr content rate gradually decreases with distance from the transparent substrate 10 is located on the transparent substrate 10 side, and a partial region in which the Kr content rate gradually increases with distance from the transparent substrate 10. may be located on the side opposite to the transparent substrate 10 .

The light-transmissive conductive layer 20 preferably contains only Kr as rare gas atoms. Such a configuration is preferable from the viewpoint of achieving low resistance in the light transmissive conductive layer 20'. In addition, this configuration is suitable for suppressing crystallization under low-temperature conditions in the amorphous light-transmissive conductive layer 20, and is therefore suitable for ensuring good storage stability.

When the light transmissive conductive layer 20 contains rare gas atoms other than Kr, examples of the rare gas atoms other than Kr include argon (Ar) and xenon (Xe). From the viewpoint of reducing the manufacturing cost of the transparent conductive film X, the light-transmissive conductive layer 20 preferably does not contain Xe.

The content of rare gas atoms (including Kr) in the light-transmissive conductive layer 20 is, for example, 0.5 atomic % or less, preferably 0.3 atomic % or less, more preferably 0.3 atomic % or less, in the entire thickness direction D. It is 0.2 atomic % or less. Such a configuration is suitable for achieving good crystal growth and forming large crystal grains when the amorphous light-transmitting conductive layer 20 is crystallized by heating, and thus has low resistance and light-transmitting properties. Suitable for obtaining the conductive layer 20'. In addition, the rare gas atom content ratio in the light-transmitting conductive layer 20 is, for example, 0.0001 atomic % or more in the entire thickness direction D.

The thickness of the light-transmitting conductive layer 20 is, for example, 10 nm or more, preferably 30 nm or more, more preferably 35 nm or more, and even more preferably 40 nm or more. Such a configuration is suitable for reducing the resistance of the light transmissive conductive layer 20'. In addition, this configuration is suitable for suppressing crystallization under low-temperature conditions in the amorphous light-transmissive conductive layer 20, and is therefore suitable for ensuring good storage stability.

The thickness of the light-transmitting conductive layer 20 is, for example, 1000 nm or less, preferably less than 300 nm, more preferably 250 nm or less, even more preferably 200 nm or less, even more preferably 160 nm or less, particularly preferably 150 nm or less, most preferably 148 nm or less. is. Such a configuration is suitable for reducing the compressive residual stress of the light-transmitting conductive layer 20 and suppressing warping of the transparent conductive film X.

The total light transmittance (JIS K 7375-2008) of the light-transmitting conductive layer 20 is preferably 60% or more, more preferably 80% or more, still more preferably 85% or more. Such a configuration is suitable for ensuring transparency in the light transmissive conductive layer 20 . Further, the total light transmittance of the light transmissive conductive layer 20 is, for example, 100% or less.

The surface resistance of the light-transmitting conductive layer 20 is preferably 200Ω/□ or less, more preferably 175Ω/□ or less. Such a configuration is suitable for forming a low-resistance light-transmitting conductive layer 20 ′ from the light-transmitting conductive layer 20 . The surface resistance of the light transmissive conductive layer 20 is, for example, 120Ω/□ or more. The surface resistance of the conductor film can be measured by the four-probe method according to JIS K7194.

The specific resistance of the light-transmissive conductive layer 20 after heat treatment at 130° C. for 1.5 hours is preferably 2.2×10 ⁻⁴ Ω·cm or less, more preferably 2×10 ⁻⁴ Ω·cm or less. , more preferably 1.9×10 ⁻⁴ Ω·cm or less, and particularly preferably 1.8×10 ⁻⁴ Ω·cm or less. Such a configuration is suitable for forming a low-resistance light-transmitting conductive layer 20 ′ from the light-transmitting conductive layer 20 . The specific resistance of the light-transmitting conductive layer 20 is, for example, 7.5×10 ⁻⁴ Ω·cm or more. The specific resistance is obtained by multiplying the surface resistance by the thickness.

The carrier density in the light-transmissive conductive layer 20 is 40×10 ¹⁹ cm ⁻³ or more, preferably 45×10 ¹⁹ cm ⁻³ or more, more preferably 47×10 ¹⁹ cm ⁻³ or more. The carrier density in the light-transmissive conductive layer 20 is preferably 100×10 ¹⁹ cm ⁻³ or less, more preferably 80×10 ¹⁹ cm ⁻³ or less. Such a configuration is suitable for realizing a high crystallization speed in the light-transmitting conductive layer 20. FIG. In addition, this configuration is suitable for suppressing crystallization under low-temperature conditions in the amorphous light-transmissive conductive layer 20, and is therefore suitable for ensuring good storage stability. The carrier density can be adjusted, for example, by adjusting the Kr content ratio in the light-transmitting conductive layer 20 and adjusting various conditions when forming the light-transmitting conductive layer 20 by sputtering. The conditions include, for example, the temperature of the base (transparent substrate 10 in this embodiment) on which the light-transmissive conductive layer 20 is formed, and the amount of oxygen introduced into the film forming chamber. The specific resistance can also be adjusted by adjusting the surface properties of the base on which the light-transmitting conductive layer 20 is formed (in this embodiment, the surface properties of the functional layer 12).

The hole mobility in the light-transmitting conductive layer 20 is preferably 5 cm ² /V·s or more, more preferably 8 cm ² /V·s or more, and still more preferably 10 cm ² /V·s or more. The hole mobility of the light transmissive conductive layer 20 is preferably 18 cm ² /V·s or less, more preferably 17 cm ² /V·s or less. Such a configuration is suitable for realizing a high crystallization speed in the light-transmitting conductive layer 20. FIG. In addition, this configuration is suitable for suppressing crystallization under low-temperature conditions in the amorphous light-transmissive conductive layer 20, and is therefore suitable for ensuring good storage stability. The hole mobility can be adjusted, for example, by adjusting the Kr content in the light-transmitting conductive layer 20 and adjusting various conditions when forming the light-transmitting conductive layer 20 by sputtering. The conditions include, for example, the temperature of the substrate (transparent substrate 10 in this embodiment) on which the amorphous light-transmitting conductive layer is formed, and the temperature of the substrate (transparent substrate 10 in this embodiment). Sputter output and the like can be mentioned. The hole mobility can also be adjusted by adjusting the surface properties such as the surface shape of the base on which the amorphous light-transmitting conductive layer is formed (in this embodiment, the surface properties of the functional layer 12).

Whether the light-transmitting conductive layer is crystalline can be determined, for example, as follows. First, the light-transmissive conductive layer (the light-transmissive conductive layer 20 on the transparent substrate 10 in the case of the transparent conductive film X) is immersed in hydrochloric acid having a concentration of 5% by mass at 35° C. for 15 minutes. Next, the light-transmitting conductive layer is washed with water and then dried. Next, on the exposed plane of the light-transmitting conductive layer (the surface of the light-transmitting conductive layer 20 opposite to the transparent substrate 10 in the transparent conductive film X), the resistance between a pair of terminals separated by a distance of 15 mm (Resistance between terminals) is measured. In this measurement, if the inter-terminal resistance is 10 kΩ or less, the light-transmitting conductive layer is crystalline.

The transparent conductive film X is produced, for example, as follows.

First, as shown in FIG. 2A, a resin film 11 is prepared.

Next, as shown in FIG. 2B, the functional layer 12 is formed on one surface of the resin film 11 in the thickness direction D. Next, as shown in FIG. A transparent substrate 10 is produced by forming the functional layer 12 on the resin film 11 .

The above functional layer 12 as a hard coat layer can be formed by applying a curable resin composition on the resin film 11 to form a coating film, and then curing the coating film. When the curable resin composition contains an ultraviolet-curable resin, the coating film is cured by ultraviolet irradiation. When the curable resin composition contains a thermosetting resin, the coating is cured by heating.

If necessary, the exposed surface of the functional layer 12 formed on the resin film 11 is subjected to a surface modification treatment. When plasma processing is performed as surface modification processing, argon gas, for example, is used as an inert gas. Also, the discharge power in the plasma treatment is, for example, 100 W or more and, for example, 500 W or less.

Next, as shown in FIG. 2C, the transparent conductive layer 20 is formed on the transparent substrate 10 (film formation step). Specifically, a film of material is formed on the functional layer 12 of the transparent substrate 10 by a sputtering method to form the amorphous light-transmitting conductive layer 20 .

In the sputtering method, it is preferable to use a sputtering film forming apparatus capable of carrying out the film forming process by a roll-to-roll method. In the production of the transparent conductive film X, when a roll-to-roll type sputtering deposition apparatus is used, the long transparent substrate 10 is run from a delivery roll provided in the apparatus to a take-up roll, and the transparent substrate is A light-transmitting conductive layer 20 is formed by depositing a material on the material 10 . In the sputtering method, a sputtering film forming apparatus having one film forming chamber may be used, or a sputtering film forming apparatus having a plurality of film forming chambers arranged in order along the traveling path of the transparent substrate 10 may be used. An apparatus may be used (when forming the light-transmitting conductive layer 20 including the first layer and the second layer described above, a sputtering film forming apparatus having two or more film forming chambers is used). .

Specifically, in the sputtering method, a negative voltage is applied to a target placed on a cathode in the film forming chamber while introducing a sputtering gas (inert gas) into the film forming chamber under vacuum conditions. As a result, glow discharge is generated to ionize the gas atoms, the gas ions collide with the target surface at high speed, the target material is ejected from the target surface, and the ejected target material is deposited on the functional layer 12 of the transparent substrate 10. deposit on

As the material of the target placed on the cathode in the deposition chamber, the conductive oxide described above for the light-transmitting conductive layer 20 is used, preferably the indium-containing conductive oxide, and more preferably ITO. Used. When ITO is used, the ratio of the content of tin oxide to the total content of tin oxide and indium oxide in the ITO is preferably 1% by mass or more, more preferably 3% by mass or more, and still more preferably 5% by mass or more. is particularly preferably 7% by mass or more, preferably 15% by mass or less, more preferably 13% by mass or less, and still more preferably 12% by mass or less.

The sputtering method is preferably a reactive sputtering method. In the reactive sputtering method, a reactive gas is introduced into the deposition chamber in addition to the sputtering gas.

When forming the light-transmitting conductive layer 20 containing Kr over the entire thickness direction D, the gas introduced into the deposition chamber contains Kr as a sputtering gas and oxygen as a reactive gas. The sputtering gas may contain an inert gas other than Kr. Examples of inert gases other than Kr include rare gas atoms other than Kr. Noble gas atoms include, for example, Ar and Xe. When the sputtering gas contains an inert gas other than Kr, the content is preferably 5% by volume or less, more preferably 3% by volume or less.

In the reactive sputtering method, the ratio of the introduction amount of oxygen to the total introduction amount of the sputtering gas and oxygen introduced into the film forming chamber is, for example, 0.1 flow % or more and, for example, 5 flow % or less.

The atmospheric pressure in the film formation chamber during film formation by the sputtering method (sputter film formation) is, for example, 0.02 Pa or higher and, for example, 1 Pa or lower.

The temperature of the transparent substrate 10 during sputtering film formation is, for example, 100° C. or lower, preferably 50° C. or lower, more preferably 30° C. or lower, and is, for example, −20° C. or higher, preferably −10° C. or higher, more preferably. is -7°C or higher.

Power supplies for applying voltage to the target include, for example, DC power supplies, AC power supplies, MF power supplies, and RF power supplies. As a power supply, a DC power supply and an RF power supply may be used together. The discharge voltage during sputtering film formation is, for example, 200 V or higher and, for example, 400 V or lower.

For example, the transparent conductive film X can be produced as described above.

The light-transmissive conductive layer 20 in the transparent conductive film X may be patterned as schematically shown in FIG. By etching the light-transmitting conductive layer 20 through a predetermined etching mask, the light-transmitting conductive layer 20 can be patterned. The patterned light transmissive conductive layer 20 functions, for example, as a wiring pattern.

Also, the light-transmitting conductive layer 20 in the transparent conductive film X is converted into a crystalline light-transmitting conductive layer 20' (shown in FIG. 4) by heating. Means for heating include, for example, infrared heaters and ovens. The heating temperature is, for example, 100° C. or higher, preferably 120° C. or higher, from the viewpoint of ensuring a high crystallization rate. The heating temperature is preferably 200° C. or lower, more preferably 180° C. or lower, and even more preferably 170° C. or lower, from the viewpoint of suppressing the influence of heating on the transparent substrate 10 . The heating temperature is preferably 120° C. or higher, more preferably 130° C. or higher. The heating time is preferably 120 minutes or less, more preferably 90 minutes or less, still more preferably 70 minutes or less. The heating time is preferably 10 minutes or longer, more preferably 20 minutes or longer. The patterning of the light transmissive conductive layer 20 may be performed before heating for crystallization or after heating for crystallization.

The surface resistance of the light-transmissive conductive layer 20' is, for example, 200Ω/□ or less, preferably 100Ω/□ or less, more preferably 50Ω/□ or less, and even more preferably 45Ω/□ or less. The surface resistance of the light transmissive conductive layer 20' is, for example, 1Ω/□ or more. These configurations relating to surface resistance include a light-transmissive conductive layer 20' in touch sensor devices, light control elements, photoelectric conversion elements, heat ray control members, antenna members, electromagnetic wave shield members, lighting devices, image display devices, and the like. When the transparent conductive film X is provided, it is suitable for ensuring the low resistance required for the light transmissive conductive layer 20'.

The specific resistance of the light transmissive conductive layer 20′ is preferably 2.2×10 ⁻⁴ Ω·cm or less, more preferably 2×10 ⁻⁴ Ω·cm or less, and still more preferably 1.9×10 ⁻⁴ Ω. ·cm or less, particularly preferably 1.8×10 ⁻⁴ Ω·cm or less. The specific resistance of the light transmissive conductive layer 20' is, for example, 0.1×10 ⁻⁴ Ω·cm or more. These structures related to specific resistance include a light-transmissive conductive layer 20' in a touch sensor device, a light control element, a photoelectric conversion element, a heat ray control member, an antenna member, an electromagnetic wave shield member, a lighting device, an image display device, and the like. When the transparent conductive film X is provided, it is suitable for ensuring the low resistance required for the light transmissive conductive layer 20'.

The total light transmittance (JIS K 7375-2008) of the light-transmissive conductive layer 20' is preferably 60% or higher, more preferably 80% or higher, and even more preferably 85% or higher. Such a configuration is suitable for ensuring transparency in the light transmissive conductive layer 20'. Further, the total light transmittance of the light transmissive conductive layer 20' is, for example, 100% or less.

In the transparent conductive film X, as described above, the light-transmitting conductive layer 20 contains krypton, and the carrier density in the light-transmitting conductive layer 20 is 40×10 ¹⁹ cm ^{−3 or} more, preferably It is 45×10 ¹⁹ cm ⁻³ or more, more preferably 47×10 ¹⁹ cm ⁻³ or more.

Such a configuration of the transparent conductive film X is suitable for realizing a high crystallization speed in the light-transmitting conductive layer 20 and ensuring good storage stability. Specifically, it is as shown in Examples and Comparative Examples below.

In the transparent conductive film X, the functional layer 12 is provided in order to achieve high adhesion of the light-transmitting conductive layer (the light-transmitting conductive layer 20 or the light-transmitting conductive layer 20', hereinafter the same) to the transparent substrate 10. may be an adhesion improving layer. The structure in which the functional layer 12 is an adhesion improving layer is suitable for ensuring adhesion between the transparent substrate 10 and the light-transmitting conductive layer.

The functional layer 12 may be a refractive index adjusting layer (index-matching layer) for adjusting the reflectance of the surface (one side in the thickness direction D) of the transparent substrate 10 . The configuration in which the functional layer 12 is a refractive index adjusting layer is suitable for making the pattern shape of the light-transmitting conductive layer less visible when the light-transmitting conductive layer on the transparent substrate 10 is patterned.

The functional layer 12 may be a peeling functional layer for practically peeling the light-transmissive conductive layer from the transparent substrate 10 . The configuration in which the functional layer 12 is a peeling functional layer is suitable for peeling the light-transmitting conductive layer from the transparent substrate 10 and transferring the light-transmitting conductive layer to another member.

The functional layer 12 may be a composite layer in which a plurality of layers are arranged in the thickness direction D. The composite layer preferably includes two or more layers selected from the group consisting of a hard coat layer, an adhesion improving layer, a refractive index adjusting layer, and a release functional layer. Such a configuration is suitable for compositely expressing the above-described functions of each selected layer in the functional layer 12 . In a preferred embodiment, the functional layer 12 includes an adhesion improving layer, a hard coat layer, and a refractive index adjusting layer on the resin film 11 toward one side in the thickness direction D in this order. In another preferred embodiment, the functional layer 12 includes, on the resin film 11, a release functional layer, a hard coat layer, and a refractive index adjusting layer in this order toward one side in the thickness direction D.

The transparent conductive film X is used after being attached to an article and patterned as necessary. The transparent conductive film X is adhered to an article via, for example, a fixing functional layer.

Articles include, for example, elements, members, and devices. That is, examples of articles with a transparent conductive film include elements with a transparent conductive film, members with a transparent conductive film, and devices with a transparent conductive film.

Devices include, for example, light control devices and photoelectric conversion devices. Examples of the light control device include a current-driven light control device and an electric field drive light control device. Current-driven light control devices include, for example, electrochromic (EC) light control devices. Examples of electric field-driven light control devices include PDLC (polymer dispersed liquid crystal) light control devices, PNLC (polymer network liquid crystal) light control devices, and SPD (suspended particle device) light control devices. Examples of photoelectric conversion elements include solar cells. Solar cells include, for example, organic thin-film solar cells and dye-sensitized solar cells. Examples of the member include an electromagnetic wave shield member, a heat ray control member, a heater member, and an antenna member. Devices include, for example, touch sensor devices, lighting devices, and image display devices.

Examples of the above-mentioned fixing functional layer include an adhesive layer and an adhesive layer. As a material for the fixing function layer, any material can be used without particular limitation as long as it is transparent and exhibits a fixing function. The fixation functional layer is preferably made of resin. Examples of resins include acrylic resins, silicone resins, polyester resins, polyurethane resins, polyamide resins, polyvinyl ether resins, vinyl acetate/vinyl chloride copolymers, modified polyolefin resins, epoxy resins, fluorine resins, natural rubbers, and synthetic rubbers. be done. As the resin, an acrylic resin is preferable because it exhibits adhesive properties such as cohesiveness, adhesiveness, and moderate wettability, is excellent in transparency, and is excellent in weather resistance and heat resistance.

The fixing functional layer (resin forming the fixing functional layer) may contain a corrosion inhibitor to suppress corrosion of the light-transmissive conductive layer 20'. The fixing functional layer (resin forming the fixing functional layer) contains a migration inhibitor (for example, the material disclosed in JP-A-2015-022397) in order to suppress the migration of the light-transmitting conductive layer 20'. good too. Further, the fixing functional layer (resin forming the fixing functional layer) may contain an ultraviolet absorber in order to suppress deterioration of the article when it is used outdoors. Examples of ultraviolet absorbers include benzophenone compounds, benzotriazole compounds, salicylic acid compounds, oxalic acid anilide compounds, cyanoacrylate compounds, and triazine compounds.

Further, when the transparent substrate 10 of the transparent conductive film X is fixed to the article via the fixing functional layer, the light-transmitting conductive layer 20' (light-transmitting conductive layer after patterning) in the transparent conductive film X 20') are exposed. In such cases, a cover layer may be placed over the exposed surface of the light transmissive conductive layer 20'. The cover layer is a layer that covers the light-transmitting conductive layer 20', improves the reliability of the light-transmitting conductive layer 20', and can suppress functional deterioration due to damage to the light-transmitting conductive layer 20'. Such a cover layer is preferably made of a dielectric material, more preferably a composite material of a resin and an inorganic material. Examples of the resin include the resins described above for the fixing functional layer. Inorganic materials include, for example, inorganic oxides and fluorides. Inorganic oxides include, for example, silicon oxide, titanium oxide, niobium oxide, aluminum oxide, zirconium dioxide, and calcium oxide. Examples of fluorides include magnesium fluoride. In addition, the cover layer (mixture of resin and inorganic material) may contain the above-described corrosion inhibitor, migration inhibitor, and ultraviolet absorber.

EXAMPLES The present invention will be specifically described below with reference to Examples. The invention is not limited to the examples. In addition, the specific numerical values such as the compounding amount (content), physical property values, parameters, etc. described below are the corresponding compounding amounts ( content), physical properties, parameters, etc., upper limits (values defined as “less than” or “less than”) or lower limits (values defined as “greater than” or “greater than”).

[Example 1]
An ultraviolet curable resin containing an acrylic resin is applied to one surface of a long cycloolefin polymer (COP) film (trade name “Zeonor”, thickness 40 μm, manufactured by Zeon Corporation) as a transparent resin film (base material). The composition was applied to form a coating film. Next, the coating film was cured by ultraviolet irradiation to form a hard coat layer (thickness: 1 μm). Next, an ultraviolet curable resin composition (a composite resin composition containing zirconia particles) for forming a refractive index adjusting layer was applied onto the hard coat layer to form a coating film. Next, the coating film was cured by UV irradiation to form a refractive index adjusting layer (thickness: 90 nm, refractive index: 1.62) on the hard coat layer. In this manner, a transparent base material including a resin film, a hard coat layer, and a refractive index adjusting layer in this order was produced (transparent base material producing step).

Next, a 43 nm-thick amorphous light-transmitting conductive layer was formed on the hard coat layer of the transparent substrate by reactive sputtering (film formation step). In the reactive sputtering method, a sputter deposition apparatus (DC magnetron sputtering apparatus) capable of performing a deposition process in a roll-to-roll system was used. The conditions for sputtering film formation in this example are as follows.

A sintered body of indium oxide and tin oxide (with a tin oxide concentration of 10% by mass) was used as a target. A DC power supply was used as a power supply for applying voltage to the target. The horizontal magnetic field strength on the target was set to 90 mT. The film-forming temperature (the temperature of the transparent substrate on which the light-transmitting conductive layer is laminated) was set at 20°C. Further, after evacuating the film forming chamber to an ultimate degree of vacuum of 0.8×10 ⁻⁴ Pa in the film forming chamber provided with the apparatus, Kr as a sputtering gas and reactive gas Kr are introduced into the film forming chamber. Oxygen was introduced, and the pressure in the film forming chamber was set to 0.2 Pa. The ratio of the oxygen introduction amount to the total introduction amount of Kr and oxygen introduced into the film formation chamber is about 2 flow rate %, and the oxygen introduction amount is in the area of the surface resistance-oxygen introduction amount curve, as shown in FIG. It was adjusted within R and the surface resistance value of the film to be formed was 175Ω/□. The surface resistance-oxygen introduction amount curve shown in FIG. Oxygen introduction amount dependence can be prepared by investigating in advance.

As described above, the transparent conductive film of Example 1 was produced. The light-transmissive conductive layer (43 nm thick, amorphous) of the transparent conductive film of Example 1 consists of a single Kr-containing ITO layer.

[Example 2 and Comparative Example 1]
Transparent conductive films of Example 2 and Comparative Example 1 were produced in the same manner as the transparent conductive film of Example 1, except for the following.

In the process of producing the transparent conductive film of Example 2, in the film formation process, the amount of oxygen introduced was adjusted so that the surface resistance of the film formed was 135 Ω/□, and the light-transmitting conductive layer formed was was 55 nm.

In the process of producing the transparent conductive film of Comparative Example 1, the thickness of the light-transmissive conductive layer formed in the film forming process was set to 51 nm.

The transparent conductive layer (amorphous) of each transparent conductive film of Example 2 and Comparative Example 1 consisted of a single Kr-containing ITO layer.

[Example 3]
In the film formation step, the transparent conductive film of Example 3 was formed in the same manner as the transparent conductive film of Example 1, except that the thickness of the formed light-transmitting conductive layer was changed from 43 nm to 41 nm (Example 2). A transparent conductive film was produced. The light-transmissive conductive layer (amorphous) of the transparent conductive film of Example 3 consists of a single Kr-containing ITO layer.

[Comparative Examples 2 to 4]
Transparent conductive films of Comparative Examples 2 to 4 were produced in the same manner as the transparent conductive film of Example 1, except for the following.

In the manufacturing process of the transparent conductive film of Comparative Example 2, a long polyethylene terephthalate (PET) film (thickness: 50 μm, manufactured by Mitsubishi Chemical Corporation) was used in place of the COP film in the transparent substrate manufacturing process, and In the film forming process, Ar was used as the sputtering gas, the film forming pressure was set to 0.4 Pa, and the amount of oxygen introduced was adjusted so that the surface resistance of the film to be formed was 115 Ω/□ (Comparative Example 2). The thickness of the light-transmissive conductive layer was set to 35 nm.

In the manufacturing process of the transparent conductive film of Comparative Example 3, in the film forming process, Ar was used as the sputtering gas, the film forming pressure was 0.4 Pa, and the surface resistance of the formed film was 67 Ω/□ (Comparative Example 2). The amount of oxygen introduced was adjusted so that the thickness of the formed light-transmissive conductive layer was set to 70 nm.

In the manufacturing process of the transparent conductive film of Comparative Example 4, a long PET film (thickness: 50 μm, manufactured by Mitsubishi Chemical Corporation) was used in place of the COP film in the transparent substrate manufacturing process, and , Ar was used as the sputtering gas, the film formation pressure was 0.4 Pa, and the amount of oxygen introduced was adjusted so that the surface resistance of the film formed was 64 Ω / □ (Comparative Example 2). The thickness of the conductive layer was set to 60 nm.

The light-transmissive conductive layer (crystalline) of each of the transparent conductive films of Comparative Examples 2-4 consisted of a single Ar-containing ITO layer.

[Comparative Example 5]
A transparent conductive film of Comparative Example 5 was produced in the same manner as the transparent conductive film of Example 1, except for the following.

In the film forming process, a first sputter film formation for forming a first layer (thickness of 17 nm) on a transparent substrate, and a second sputter film formation for forming a second layer (thickness of 8 nm) on the first layer. and were implemented sequentially.

The conditions for the first sputtering film formation are as follows. A sintered body of indium oxide and tin oxide (with a tin oxide concentration of 10% by mass) was used as a target. A DC power supply was used as a power supply for applying voltage to the target. The horizontal magnetic field strength on the target was set to 90 mT. The film formation temperature was -5°C. Further, after evacuating the first film forming chamber until the final degree of vacuum in the first film forming chamber provided in the apparatus reaches 0.8×10 ⁻⁴ Pa, Ar as a sputtering gas is introduced into the first film forming chamber. , and oxygen as a reactive gas were introduced, and the pressure in the film formation chamber was set to 0.4 Pa. The amount of oxygen introduced into the film forming chamber was adjusted so that the surface resistance value of the formed film was 230Ω/□.

The conditions for the second sputtering film formation are as follows. A sintered body of indium oxide and tin oxide (with a tin oxide concentration of 3% by mass) was used as a target. After evacuating the second film forming chamber until the ultimate vacuum degree in the second film forming chamber provided in the apparatus reaches 0.8 × 10 ^-4 Pa, Ar as a sputtering gas and reacting in the second film forming chamber Oxygen was introduced as a chemical gas, and the pressure in the film formation chamber was set to 0.4 Pa. Other conditions for the second sputtering film formation are the same as those for the first sputtering film formation.

The light-transmitting conductive layer (thickness: 25 nm, amorphous) of the transparent conductive film of Comparative Example 5 consists of a first layer (thickness: 17 nm) consisting of an Ar-containing ITO layer and a second layer consisting of an Ar-containing ITO layer. (thickness 8 nm) in order from the transparent substrate side.

<Thickness of light transmissive conductive layer>
The thickness of the light-transmissive conductive layer in each of the transparent conductive films of Examples 1-3 and Comparative Examples 1-5 was measured by FE-TEM observation. Specifically, first, samples for cross-sectional observation of each light-transmissive conductive layer in Examples 1 to 3 and Comparative Examples 1 to 5 were prepared by the FIB microsampling method. In the FIB microsampling method, an FIB device (trade name “FB2200”, manufactured by Hitachi) was used, and the acceleration voltage was set to 10 kV. Next, the thickness of the light-transmitting conductive layer in the sample for cross-sectional observation was measured by FE-TEM observation. In the FE-TEM observation, an FE-TEM apparatus (trade name “JEM-2800”, manufactured by JEOL) was used with an acceleration voltage of 200 kV.

For the thickness of the first layer of the light-transmitting conductive layer in Comparative Example 5, a sample for cross-sectional observation was prepared from the intermediate product before forming the second layer on the first layer, and the FE- Measured by TEM observation. The thickness of the second layer of the light-transmitting conductive layers in Comparative Example 3 was obtained by subtracting the thickness of the first layer from the total thickness of the light-transmitting conductive layers in Comparative Example 5.

<Hall mobility and carrier density>
For each of the transparent conductive films of Examples 1-3 and Comparative Examples 1-5, the hole mobility and carrier density of the light-transmissive conductive layer were measured. For this measurement, a Hall effect measurement system (trade name "HL5500PC", manufactured by Bio-Rad) was used. Table 1 shows the values of hole mobility (cm ² /V·s) and carrier density (cm ⁻³ ) obtained by this measurement.

<Resistance>
For each of the transparent conductive films of Examples 1-3 and Comparative Examples 1-5, the specific resistance of the light-transmissive conductive layer after heat treatment was examined. In the heat treatment, a hot air oven was used as a heating means, the heating temperature was 130° C., and the heating time was 90 minutes. After measuring the surface resistance of the light-transmitting conductive layer by the four-terminal method according to JIS K 7194 (1994), multiplying the surface resistance value by the thickness of the light-transmitting conductive layer gives the light-transmitting conductive layer. (Since the light-transmitting conductive layer in Comparative Example 1 was not crystallized by the heat treatment, the specific resistance of the same layer could not be measured.). Table 1 shows the results.

<Crystalization rate>
For each of the transparent conductive films of Examples 1-3 and Comparative Examples 1-5, the crystallization speed of the light-transmitting conductive layer was examined. Specifically, first, two types of samples (a first sample and a second sample) were prepared for each transparent conductive film. A first sample was prepared by heat-treating a transparent conductive film at 140° C. for 30 minutes. A second sample was prepared by heat treating a transparent conductive film at 140° C. for 60 minutes. Next, the sample was immersed in hydrochloric acid having a concentration of 5% by mass at 35° C. for 15 minutes. The samples were then washed with water and dried. Next, the resistance between a pair of terminals spaced apart by 15 mm (inter-terminal resistance) was measured on the exposed plane of the light-transmitting conductive layer of the sample. In this measurement, when the inter-terminal resistance was 10 kΩ or less, it was judged that the crystallization of the light-transmitting conductive layer was completed.

When crystallization was completed in both the first sample and the second sample, the crystallization completion time of the light-transmitting conductive layer was 30 minutes or less, and the crystallization rate was evaluated as ⊚. When crystallization is not completed in the first sample and crystallization is completed in the second sample, the crystallization completion time of the light-transmitting conductive layer is more than 30 minutes and 60 minutes or less, The crystallization speed was evaluated as ◯. When crystallization was not completed in both the first sample and the second sample, the crystallization completion time of the light-transmitting conductive layer exceeded 60 minutes, and the crystallization speed was evaluated as x. These evaluation results are shown in Table 1.

<Storage stability>
For each of the transparent conductive films of Examples 1-3 and Comparative Examples 1-5, storage stability (extent of suppression of crystallization during storage) of the amorphous light-transmissive conductive layer was examined. Specifically, first, two types of samples (a third sample and a fourth sample) were prepared for each transparent conductive film. A third sample was prepared by allowing the transparent conductive film to stand at 50° C. for 15 hours. A fourth sample was prepared by allowing the transparent conductive film to stand at 80° C. for 6 hours. Next, the sample was heat-treated in a hot air oven (crystallization of the light-transmitting conductive layer). The heating temperature was 130° C. and the heating time was 90 minutes. Next, the surface of the light-transmitting conductive layer in the sample was observed with an optical microscope to confirm the presence or absence of cracks (magnification: 100 times, observation range: 2 cm x 2 cm).

Regarding the storage stability of the transparent conductive film, the case where no cracks were confirmed in the light-transmitting conductive layer in both the 3rd sample and the 4th sample was evaluated as ⊚. A case where cracks were observed in the transparent conductive layer was evaluated as ◯, and a case where cracks were observed in the light-transmissive conductive layer in both the third and fourth samples was evaluated as x. These evaluation results are shown in Table 1.

<Confirmation of Kr atoms in the light-transmitting conductive layer>
It was confirmed as follows that each light-transmissive conductive layer in Examples 1 to 3 and Comparative Example 1 contained Kr atoms. First, using a scanning fluorescent X-ray analyzer (trade name "ZSX PrimusIV", manufactured by Rigaku), the fluorescent X-ray analysis measurement was repeated five times under the following measurement conditions, and the average value of each scanning angle was calculated. and an X-ray spectrum was created. It was confirmed that Kr atoms were contained in the light-transmissive conductive layer by confirming that a peak appeared in the vicinity of a scanning angle of 28.2° in the prepared X-ray spectrum.

<Measurement conditions>
Spectrum; Kr-KA
Measurement diameter: 30mm
Atmosphere: Vacuum Target: Rh
Tube voltage: 50kV
Tube current: 60mA
Primary filter: Ni40
Scanning angle (deg): 27.0 to 29.5
Step (deg): 0.020
Speed (deg/min): 0.75
Attenuator: 1/1
Slit: S2
Analysis crystal: LiF (200)
Detector: SC
PHA: 100-300

[evaluation]
In each of the transparent conductive films of Examples 1 to 3, the light-transmitting conductive layer contains Kr, and the carrier density in the light-transmitting conductive layer is 40×10 ¹⁹ cm ⁻³ or more. In each of the transparent conductive films of Examples 1 to 3, a high crystallization rate was achieved in the light-transmissive conductive layer, and good storage stability was ensured. On the other hand, the transparent conductive film of Comparative Example 1 (the carrier density of the light-transmitting conductive layer is less than 40×10 ¹⁹ cm ⁻³ ) and the transparent conductive films of Comparative Examples 2 and 3 (light-transmitting conductive The layer does not contain Kr and the carrier density of the same layer is 40 × 10 ¹⁹ cm ^-3 or more), and each transparent conductive film of Comparative Examples 4 and 5 (the light-transmitting conductive layer contains Kr and the carrier density in the same layer is less than 40×10 ¹⁹ cm ⁻³ ), it was not possible to achieve both a high crystallization rate and good storage stability.

The transparent conductive film of the present invention can be used, for example, as a supply material for conductive films for patterning transparent electrodes in various devices such as liquid crystal displays, touch panels, and optical sensors.

X transparent conductive film D thickness direction 10 transparent substrate 11 resin film 12 functional layer 20 light transmissive conductive layer

Claims (4)

Equipped with a transparent substrate and an amorphous light-transmitting conductive layer in this order in the thickness direction,
The light-transmitting conductive layer contains krypton, has a carrier density of 40×10 ¹⁹ cm ⁻³ or more and 100×10 ¹⁹ cm ⁻³ or less , and has a Hall mobility of 18 cm ² /V·s or less. , transparent conductive film. 2. The transparent conductive film of claim 1, wherein the light transmissive conductive layer comprises an indium-containing conductive oxide. 3. The transparent conductive film according to claim 1, wherein the light-transmissive conductive layer has a thickness of 30 nm or more. The transparent material according to any one of claims 1 to 3 , wherein the light-transmitting conductive layer has a resistivity of 2.2 × 10 ^-4 Ω·cm or less after heat treatment at 130°C for 1.5 hours. conductive film.

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