Homogeneous composite transparent conductive film and preparation method and application thereof

Abstract

The invention belongs to the technical field of optoelectronic information materials, and particularly relates to a homogeneous composite transparent conductive film and a preparation method and application thereof. The homogeneous composite transparent conductive film refers to a plurality of layers of transparent conductive films which are sequentially laminated on at least one side surface of a substrate, and the plurality of layers of transparent conductive films are made of the same material; the multi-layer transparent conductive film is prepared by adopting different magnetron sputtering coating process parameters. The homogeneous composite transparent conductive film disclosed by the invention has excellent performance in the aspects of heating cracking resistance and film-substrate binding force of the surface of a substrate which is not resistant to temperature, and engineering application of the transparent conductive film in corresponding devices can be expanded.

Description

Technical Field

[0001] The invention belongs to the technical field of optoelectronic information materials, and in particular relates to a homogeneous composite transparent conductive film and a preparation method and application thereof. Background Art

[0002] Transparent conductive film is a film material with high visible light transmittance and high electrical conductivity. It is widely used in solar cells, Low-E glass curtain walls, displays, light-emitting diodes, electrochromic glass, electric heating glass, electromagnetic shielding glass and other fields. Different application needs have different performance requirements for transparent conductive films. Low-E glass curtain walls focus on infrared emissivity in the near-infrared band. Transparent electrodes in the field of solar cells have high requirements for the conductivity, surface work function and matching with other functional film layers of transparent conductive films. Flexible displays and organic electric heating glass have high requirements for the crack resistance, film-base bonding and environmental test resistance of transparent conductive films.

[0003] Currently, transparent conductive films prepared on the surface of organic substrates are often affected by the thermal expansion mismatch between the film and the substrate or the non-wetting of the interface, resulting in problems such as film shedding and film cracking, which has also become a pain point in the industry.

[0004] To this end, the present invention is proposed. Summary of the invention

[0005] The main purpose of the present invention is to propose a homogeneous composite transparent conductive film and its preparation method and application. The homogeneous composite transparent conductive film in the present invention has excellent performance in terms of crack resistance and film bonding strength of heat-sensitive organic substrates, and can expand the engineering application of transparent conductive films in corresponding devices.

[0006] To achieve the above objectives, the present invention provides the following technical solutions.

[0007] In a first aspect, the present invention provides a homogeneous composite transparent conductive film. The homogeneous composite transparent conductive film includes multiple layers of transparent conductive films stacked in sequence on at least one side of a substrate, and the multiple layers of transparent conductive films are made of the same material; the multiple layers of transparent conductive films are prepared using different magnetron sputtering coating process parameters.

[0008] In some embodiments of the present invention, the material of the transparent conductive film is selected from one of indium tin oxide, indium zinc oxide, zinc oxide, zinc aluminum oxide, zinc gallium oxide and indium gallium zinc oxide.

[0009] In some embodiments of the present invention, the sheet resistance of the homogeneous composite transparent conductive film is 2Ω / □ to 20Ω / □.

[0010] In some embodiments of the present invention, the adhesion of the homogeneous composite transparent conductive film is level 0.

[0011] In some embodiments of the present invention, the homogeneous composite transparent conductive film has a crack resistance temperature of 90° C. or higher on the surface of the organic substrate for a period of more than 6 hours.

[0012] In some embodiments of the present invention, the total thickness of the multi-layer transparent conductive film is 200 nm to 1000 nm.

[0013] In some embodiments of the present invention, the thickness of a single layer of the transparent conductive film is 30 nm to 600 nm.

[0014] In some embodiments of the present invention, the thickness of a single layer of the transparent conductive film is 90 nm to 120 nm.

[0015] In some embodiments of the present invention, the total number of layers of the multi-layer transparent conductive film is no more than 10 layers.

[0016] In some embodiments of the present invention, the total number of layers of the multi-layer transparent conductive film is 3 to 6 layers.

[0017] In some embodiments of the present invention, the substrate is selected from one of organic glass, polycarbonate glass, polyethylene terephthalate substrate PET, and polyimide PI substrate.

[0018] The second aspect of the present invention provides a method for preparing the above-mentioned homogeneous composite transparent conductive film. The preparation method comprises the following steps: depositing film materials layer by layer on a substrate using a magnetron sputtering process to obtain a multilayer transparent conductive film; wherein the multilayer transparent conductive film is made of the same material; and the coating process parameters for forming each layer of the transparent conductive film are different. The process parameters for forming the multilayer transparent conductive film are adjusted so that the composite transparent conductive film adapts to the thermal expansion properties of the substrate and the wettability with the substrate surface.

[0019] In some embodiments of the present invention, the process parameters of the magnetron sputtering process include: the background vacuum is not less than 5.0×10 -3 Pa, coating power density is 0.5W / cm 2 ~5.0W / cm 2 , the coating gas pressure is 0.01Pa~1.0Pa, the target substrate distance is 50mm~300mm, the argon flow rate is 10sccm~200sccm, and the oxygen flow rate is 1sccm~50sccm.

[0020] In some embodiments of the present invention, the magnetron sputtering process is to introduce a working gas into a background vacuum environment, use a power supply to generate plasma to bombard the target material, so as to obtain a deposited film layer on the substrate, and the background vacuum of the magnetron sputtering process is not less than 5.0×10 -3 Pa.

[0021] In some embodiments of the present invention, among the process parameters for forming the multi-layer transparent conductive film, at least one of coating power density, coating gas pressure, target-substrate distance, argon flow rate, and oxygen flow rate is different.

[0022] A third aspect of the present invention provides an application of the above-mentioned homogeneous composite transparent conductive film or the homogeneous composite transparent conductive film prepared by the above-mentioned method in flexible solar cells, flexible displays, electrically heated glass and transparent parts in the cockpit.

[0023] Compared with the prior art, the present invention achieves the following technical effects:

[0024] 1. The homogeneous composite transparent conductive film in the present invention has excellent crack resistance and inter-film bonding strength on the surface of the heat-sensitive substrate, thereby expanding the engineering application of the transparent conductive film in the corresponding devices and solving the problems of easy cracking, film peeling and poor environmental resistance of the film layer during the preparation process or subsequent use.

[0025] 2. The homogeneous composite transparent conductive film of the present invention has a crack resistance temperature of more than 90° C. on organic glass and polycarbonate glass substrates for more than 6 hours, and the adhesion reaches level 0.

[0026] 3. The homogeneous composite transparent conductive film of the present invention adjusts the stress distribution of the entire film by optimizing the film material and coating process without affecting the conductivity and adding new film materials, thereby improving the film bonding strength, crack resistance and environmental resistance between the transparent conductive film and the substrate.

[0027] 4. The homogeneous composite transparent conductive film of the present invention can be prepared in one go by a magnetron sputtering process (such as a magnetron sputtering coating machine), which is simple to operate and has high process reliability.

[0028] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only used for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. In the accompanying drawings:

[0030] Figure 1 Schematic diagram of the cross section of the homogeneous composite transparent conductive ITO film prepared in Example 1;

[0031] Figure 2 Schematic diagram of the cross section of the homogeneous composite transparent conductive IZO film prepared in Example 2.

[0032] Reference numerals

[0033] 100, substrate; 200, first thin film layer; 300, second thin film layer; 400, third thin film layer; 500, fourth thin film layer; 600, fifth thin film layer. DETAILED DESCRIPTION

[0034] The exemplary embodiments of the present invention will be described in more detail below with reference to specific embodiments. It should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which the present invention belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention; the terms "including" and "having" in the specification and claims of the present invention and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0036] In the description of the embodiments of the present invention, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0037] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0038] In the description of the embodiments of the present invention, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this document generally indicates that the associated objects before and after are in an "or" relationship.

[0039] In the description of the embodiments of the present invention, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0040] Common transparent conductive films include transparent conductive oxides (such as ITO films, AZO films, etc.), metals (such as Ag films, Ag nanowires, etc.), graphene and polymers. Transparent conductive oxides have the advantages of stable properties and high transmittance. However, as a brittle material, transparent conductive oxides are prone to problems such as film cracking and film shedding, causing device damage. Current research is mainly focused on how to improve the shortcomings of film cracking and weak bonding by optimizing the overall process parameters of transparent conductive films or adding complex multiple film materials. For example, research on composite transparent conductive films is mostly focused on the layer-by-layer preparation of two or more different materials in transparent conductive films such as transparent conductive oxides / metals / graphene / polymers, and the process is complicated.

[0041] To this end, the present invention provides a homogeneous composite transparent conductive film and a preparation method thereof, so as to solve the problems of film cracking, film shedding and poor environmental resistance of the transparent conductive film in engineering applications.

[0042] On one hand, the present invention provides a homogeneous composite transparent conductive film, which includes a multilayer transparent conductive film stacked in sequence on at least one side of a substrate, and the multilayer transparent conductive film is made of the same material; the multilayer transparent conductive film is prepared using different magnetron sputtering coating process parameters.

[0043] The homogeneous composite transparent conductive film of the present invention improves stress matching between other materials of the film and stress distribution inside the film by setting up a multilayer film of the same material, thereby improving film bonding strength and environmental resistance performance such as high temperature cracking resistance.

[0044] In an embodiment of the present invention, the sheet resistance of the homogeneous composite transparent conductive film is 2Ω / □~20Ω / □, for example, it can be 13Ω / □~20Ω / □. By way of example, the sheet resistance can be one of 2Ω / □, 3Ω / □, 4Ω / □, 5Ω / □, 6Ω / □, 7Ω / □, 8Ω / □, 9Ω / □, 10Ω / □, 11Ω / □, 12Ω / □, 13Ω / □, 13.8Ω / □, 14Ω / □, 15Ω / □, 16Ω / □, 17Ω / □, 18Ω / □, 19Ω / □, 20Ω / □ or any value that satisfies the above range.

[0045] In the embodiment of the present invention, the adhesion of the homogeneous composite transparent conductive film is level 0, achieving a better film system bonding force.

[0046] In the embodiment of the present invention, for the organic glass substrate or the polycarbonate glass substrate, the crack resistance temperature of the homogeneous composite transparent conductive film is above 90° C. and the crack resistance time is above 6 hours.

[0047] In some embodiments of the present invention, the substrate is selected from organic glass, polycarbonate glass, polyethylene terephthalate (PET) substrate, polyimide (PI) substrate, etc., and can be selected according to actual conditions.

[0048] In some embodiments of the present invention, the material of the transparent conductive film may be selected from but not limited to one of indium tin oxide, indium zinc oxide, zinc oxide, zinc aluminum oxide, zinc gallium oxide, zinc oxide and indium gallium zinc oxide.

[0049] In some embodiments of the present invention, the total number of layers of the multilayer transparent conductive film is no more than 10 layers, for example, it can be 3 to 6 layers. Specifically, the total number of layers of the multilayer transparent conductive film can be one of 2 layers, 3 layers, 4 layers, 5 layers, 6 layers, 7 layers, 8 layers, 9 layers, 10 layers or any value that satisfies the above range.

[0050] In some embodiments of the present invention, the total thickness of the multilayer transparent conductive film can be 200nm to 1000nm. For example, the total thickness can be one of 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1000nm or any value satisfying the above range.

[0051] In some embodiments of the present invention, the thickness of each layer of transparent conductive film may be the same.

[0052] In some embodiments, the thickness of the single-layer transparent conductive film may be 30 nm to 600 nm, for example, 50 nm to 600 nm, or 90 nm to 120 nm. Exemplarily, the thickness of the single-layer transparent conductive film may be 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 150 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, or any value satisfying the above range.

[0053] On the other hand, the present invention also provides a method for preparing a homogeneous composite transparent conductive film, the key of which is to use the same thin film material and adjust different coating process parameters to coat the film layer by layer. Specifically, a magnetron sputtering process is used to deposit thin film materials layer by layer on a substrate to obtain a multi-layer transparent conductive film. Among them, the material of the multi-layer transparent conductive film is the same; the process parameters for forming the multi-layer transparent conductive film are adjusted, for example, the process parameters for forming the multi-layer transparent conductive film are adjusted differently so that the stress of the homogeneous composite transparent conductive film is adapted to that of an organic glass substrate or a polycarbonate substrate.

[0054] In the embodiment of the present invention, the magnetron sputtering process is to introduce working gas into the background vacuum environment, use power to generate plasma to bombard the target material, so as to obtain a deposited film on the substrate, and the background vacuum is not less than 5.0×10 -3 Pa.

[0055] The preparation method of the homogeneous composite transparent conductive film of the present invention is carried out according to the following steps.

[0056] (1) Place the cleaned substrate in a magnetron sputtering coating machine and draw the vacuum to a level not less than 5.0×10 - 3 Pa.

[0057] In some embodiments of the present invention, the vacuum is evacuated to a vacuum degree of 5.0×10 -3 Pa or less, and can be set according to actual conditions.

[0058] (2) Confirm the target material corresponding to the thin film, that is, confirm the material of the multi-layer transparent conductive film, and complete the preparation of the first layer of thin film according to the set coating process parameters.

[0059] (3) After the first layer of thin film is deposited, the second layer of thin film is prepared according to the set coating process parameters.

[0060] (4) Referring to the above steps, the remaining layers of thin films are prepared in sequence according to the set coating process parameters.

[0061] In an embodiment of the present invention, the process parameters of the magnetron sputtering process include: the coating power density is 0.5 W / cm 2 ~5.0W / cm 2 The coating gas pressure is 0.01Pa~1.0Pa, the distance between the target and the substrate, that is, the target-substrate distance is 50mm~300mm, and the working gas is argon and oxygen.

[0062] In an embodiment of the present invention, the argon gas flow rate is 10 sccm to 200 sccm. For example, the argon gas flow rate can be one of 10 sccm, 20 sccm, 30 sccm, 40 sccm, 50 sccm, 60 sccm, 70 sccm, 80 sccm, 90 sccm, 100 sccm, 110 sccm, 120 sccm, 130 sccm, 140 sccm, 150 sccm, 160 sccm, 170 sccm, 180 sccm, 190 sccm, and 200 sccm, or any value that satisfies the above range. In an embodiment of the present invention, the oxygen flow rate is 1 sccm to 50 sccm. For example, the oxygen flow rate can be one of 1 sccm, 2 sccm, 4 sccm, 5 sccm, 8 sccm, 10 sccm, 12 sccm, 14 sccm, 15 sccm, 18 sccm, 20 sccm, 22 sccm, 24 sccm, 25 sccm, 28 sccm, 30 sccm, 35 sccm, 38 sccm, 40 sccm, 45 sccm, 48 sccm, and 50 sccm, or any value that satisfies the above range.

[0063] In some embodiments of the present invention, the coating gas pressure can be 0.01Pa~1.0Pa, for example, the coating gas pressure can be 0.01Pa~0.5Pa, or 0.5Pa~1.0Pa. Exemplarily, the coating gas pressure can be one of 0.01Pa, 0.02Pa, 0.05Pa, 0.08Pa, 0.1Pa, 0.2Pa, 0.3Pa, 0.4Pa, 0.5Pa, 0.6Pa, 0.7Pa, 0.8Pa, 0.9Pa, 1.0Pa or any value that satisfies the above range.

[0064] In some embodiments of the present invention, the target-substrate distance can be 50 mm to 300 mm, for example, 60 mm to 300 mm. Exemplarily, the target-substrate distance can be 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 110 mm, 120 mm, 130 mm, 140 mm, 150 mm, 160 mm, 170 mm, 180 mm, 190 mm, 200 mm, 210 mm, 220 mm, 230 mm, 240 mm, 250 mm, 260 mm, 270 mm, 280 mm, 290 mm, 300 mm or any value that satisfies the above range.

[0065] In some embodiments of the present invention, the coating power density can be 0.5 W / cm 2 ~5.0W / cm 2 , for example, the coating power density can be 0.5W / cm 2, 0.8W / cm 2 , 1.0W / cm 2 , 2.0W / cm 2 、3.0W / cm 2 , 4.0W / cm 2 , 5.0W / cm 2 or any value that satisfies the above range.

[0066] In some embodiments of the present invention, multiple layers of transparent conductive films are all plated with the same thin film material, and different process parameters (such as process parameter 1, process parameter 2, process parameter 3, and so on) are used on the surface of the substrate to prepare multiple layers of homogeneous films layer by layer.

[0067] In some embodiments of the present invention, in the process parameters for forming a multi-layer transparent conductive film, the coating power for forming a multi-layer thin film increases gradually from the side close to the substrate to the side away from the substrate along the stacking direction of the thin film. For example, the coating power for forming the first thin film layer may be 60W, the coating power for forming the second thin film layer may be 120W, the coating power for forming the third thin film layer may be 180W, the coating power for forming the fourth thin film layer may be 240W, the coating power for forming the fifth thin film layer may be 300W, and so on.

[0068] In some embodiments of the present invention, in the process parameters for forming a multi-layer transparent conductive film, the coating pressure of the multi-layer thin film is gradually increased from the side close to the substrate to the side away from the substrate along the stacking direction of the thin film. For example, the coating pressure for forming the first thin film layer can be 0.2Pa, the coating pressure for forming the second thin film layer can be 0.3Pa, the coating pressure for forming the third thin film layer can be 0.4Pa, the coating pressure for forming the fourth thin film layer can be 0.5Pa, the coating pressure for forming the fifth thin film layer can be 0.6Pa, and so on.

[0069] In some embodiments of the present invention, the formation process parameters of adjacent transparent conductive films need to be controlled to be different, while non-adjacent transparent conductive films are allowed to be formed using the same process parameters, for example, process parameter 1 and process parameter 3 are allowed to be the same coating process parameters.

[0070] On the other hand, the present invention provides the above-mentioned homogeneous composite transparent conductive film or the homogeneous composite transparent conductive film prepared by the above-mentioned preparation method, which is applied to the use environment with high requirements on the anti-cracking and film adhesion of the transparent conductive film, such as in flexible solar cells, flexible displays, electrically heated glass and transparent parts of the cockpit, etc.

[0071] Unless otherwise defined, the technical terms used in the following examples have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. The experimental reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the raw materials, instruments and equipment used in the following examples, etc., can all be purchased on the market or can be obtained by existing methods; the amounts of the experimental reagents, unless otherwise specified, are the amounts of reagents used in conventional experimental operations; the experimental methods, unless otherwise specified, are all conventional methods.

[0072] Example 1

[0073] like Figure 1 As shown, Example 1 discloses a homogeneous composite transparent conductive ITO film, and the preparation method of the homogeneous composite transparent conductive ITO film is as follows:

[0074] (1) Organic glass was selected as the substrate 100, and the cleaned organic glass was placed in the vacuum chamber of a magnetron sputtering coating machine with a vacuum degree of 2.0×10 -3 Pa.

[0075] (2) The first layer of thin film 200 is plated on organic glass, and the ITO target is selected. The coating power density of the ITO target is set to 1.2W / cm 2 , the coating gas pressure is 0.2 Pa, the target substrate distance is 120 mm, the argon flow rate is set to 80 sccm, the oxygen flow rate is set to 14 sccm, and the thickness of the first film 200 is 90 nm.

[0076] (3) After the first layer of thin film 200 is deposited, other process parameters remain unchanged and the ITO coating power density is set to 1.5 W / cm 2 , the plating of the second layer of ITO film is completed, and the thickness of the second layer of film 300 is 90nm.

[0077] (4) After the second layer of film 300 is deposited, other process parameters remain unchanged and the ITO coating power density is set to 1.8 W / cm 2 , the plating of the third layer of ITO film is completed, and the thickness of the third layer of film 400 is 90nm.

[0078] (5) After the third layer of film 400 is deposited, other process parameters remain unchanged and the ITO coating power density is set to 2.1 W / cm 2 , the plating of the fourth ITO film is completed, and the thickness of the fourth film 500 is 90nm.

[0079] (6) After the fourth layer of film 500 is deposited, other process parameters remain unchanged and the ITO coating power density is set to 2.4 W / cm 2, the plating of the fifth ITO film is completed, and the thickness of the fifth film 600 is 90nm.

[0080] The above completes the preparation of the homogeneous composite transparent conductive ITO film.

[0081] Example 2

[0082] like Figure 2 As shown, Example 2 discloses a homogeneous composite transparent conductive IZO film, and the preparation method of the homogeneous composite transparent conductive IZO film is as follows:

[0083] (1) Organic glass was selected as the substrate 100, and the cleaned organic glass was placed in the vacuum chamber of a magnetron sputtering coating machine with a vacuum degree of 2.0×10 -3 Pa.

[0084] (2) The first layer of thin film 200 is deposited on organic glass, and the IZO target is selected. The coating power density of the IZO target is set to 2.4W / cm 2 , the target-substrate distance is 120 mm, the argon flow rate is set to 80 sccm, the oxygen flow rate is set to 14 sccm, the coating gas pressure is 0.1 Pa, and the thickness of the first thin film 200 is 120 nm.

[0085] (2) After the first layer of thin film 200 is deposited, other process parameters remain unchanged, the deposition pressure is adjusted to 0.2 Pa, and the deposition of the second layer of IZO film is completed. The thickness of the second layer of thin film 300 is 120 nm.

[0086] (3) After the second film 300 is deposited, other process parameters remain unchanged, the deposition pressure is adjusted to 0.3 Pa, and the third IZO film is prepared. The thickness of the third film 400 is 120 nm.

[0087] (4) After the coating of the third film 400 is completed, the other process parameters remain unchanged, the coating gas pressure is adjusted to 0.4 Pa, and the preparation of the fourth IZO film is completed. The thickness of the fourth film 500 is 120 nm.

[0088] Comparative Example 1

[0089] Disclosed is a transparent conductive ITO film, and the preparation method of the transparent conductive ITO film is as follows:

[0090] (1) Place the cleaned organic glass in the vacuum chamber of the magnetron sputtering coating machine with a vacuum degree of 2.0×10 -3 Pa.

[0091] (2) Thin film coating was performed on organic glass. ITO target was selected and the coating power density of ITO target was set to 1.8 W / cm 2, the coating gas pressure is 0.2Pa, the target substrate distance is 120mm, the argon flow rate is set to 80sccm, the oxygen flow rate is set to 14sccm, and the film thickness is 450nm.

[0092] Comparative Example 2

[0093] A transparent conductive IZO film is disclosed. The preparation method of the transparent conductive IZO film is as follows:

[0094] (1) Place the cleaned organic glass in the vacuum chamber of the magnetron sputtering coating machine with a vacuum degree of 2.0×10 -3 Pa.

[0095] (2) Thin film coating was performed on organic glass. IZO target was selected and the coating power density of IZO target was set to 2.4 W / cm 2 , the target-substrate distance is 120 mm, the argon flow rate is set to 80 sccm, the oxygen flow rate is set to 10 sccm, the coating gas pressure is 0.19 Pa, and the film thickness is 480 nm.

[0096] Performance Testing

[0097] Adhesion test.

[0098] The adhesion test adopts GB / T 9286-1998 standard, and the test result is level 0, which means that the film does not fall off 100%.

[0099] Sheet resistance test.

[0100] The sheet resistance of the transparent conductive film was tested using a surface resistivity meter based on a four-probe method.

[0101] Cracking resistance temperature and time test.

[0102] Refer to the high temperature heating test in GB T2423.2-2008 environmental test for electrical and electronic products. Place the film material in an oven, heat it to a certain temperature, and keep it warm for a certain period of time. After cooling, visually observe whether the film cracks.

[0103] Table 1 Performance comparison of the homogeneous composite transparent conductive film in the embodiment and the transparent conductive film in the comparative example

[0104]

[0105] It can be seen from Table 1 that the homogeneous composite transparent conductive film provided by the present invention has excellent photoelectric properties, film bonding strength, and environmental resistance test properties such as resistance to high-temperature cracking, which can solve the problems of film cracking, film shedding, and poor environmental resistance that are prone to occur in transparent conductive films during engineering applications. It can be used in environments where temperature-sensitive substrates have high requirements for the crack resistance and film adhesion of transparent conductive films, including flexible solar cells, flexible displays, electrically heated glass, and transparent parts in the cockpit.

[0106] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A homogeneous composite transparent conductive film, characterized in that: It includes multiple layers of transparent conductive films stacked in sequence on at least one side of a substrate, and the multiple layers of transparent conductive films are made of the same material; The multi-layer transparent conductive film is prepared by adopting different magnetron sputtering coating process parameters.

2. The homogeneous composite transparent conductive film according to claim 1, characterized in that: The material of the transparent conductive film is selected from one of indium tin oxide, indium zinc oxide, zinc oxide, zinc aluminum oxide, zinc gallium oxide and indium gallium zinc oxide.

3. The homogeneous composite transparent conductive film according to claim 1, characterized in that: The sheet resistance of the homogeneous composite transparent conductive film is 2Ω / □ to 20Ω / □; Preferably, the adhesion of the homogeneous composite transparent conductive film is level 0; Preferably, the homogeneous composite transparent conductive film has a crack resistance temperature of 90° C. or higher on the surface of the organic substrate, and the crack resistance time is more than 6 hours.

4. The homogeneous composite transparent conductive film according to claim 1, characterized in that: The total thickness of the multilayer transparent conductive film is 200nm to 1000nm; Preferably, the thickness of a single layer of the transparent conductive film is 30 nm to 600 nm.

5. The homogeneous composite transparent conductive film according to claim 1, characterized in that: The total number of layers of the multi-layer transparent conductive film is no more than 10 layers, preferably 3 to 6 layers.

6. The homogeneous composite transparent conductive film according to claim 1, characterized in that: The substrate is selected from one of organic glass, polycarbonate glass, polyethylene terephthalate substrate PET, and polyimide PI substrate.

7. A method for preparing the homogeneous composite transparent conductive film according to any one of claims 1 to 6, characterized in that: The preparation method comprises the following steps: The film material is deposited layer by layer on the substrate by using a magnetron sputtering process to obtain a multi-layer transparent conductive film; The materials of the multiple layers of transparent conductive films are the same; and the coating process parameters for forming each layer of the transparent conductive films are different.

8. The preparation method according to claim 7, characterized in that: The coating process parameters include: the background vacuum is not less than 5.0×10 -3 Pa, coating power density is 0.5W / cm 2 ~5.0W / cm 2 , the coating gas pressure is 0.01Pa~1.0Pa, the target substrate distance is 50mm~300mm, the argon flow rate is 10sccm~200sccm, and the oxygen flow rate is 1sccm~50sccm.

9. The preparation method according to claim 7 or 8, characterized in that: Among the process parameters for forming the multi-layer transparent conductive film, at least one of the coating power density, coating gas pressure, target-substrate distance, argon gas flow rate, and oxygen flow rate is different.

10. Use of the homogeneous composite transparent conductive film according to any one of claims 1 to 6 or the homogeneous composite transparent conductive film prepared by the preparation method according to any one of claims 7 to 9 in flexible solar cells, flexible displays, electrically heated glass and transparent parts of cockpits.

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