Heterogeneous 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 heterogeneous composite transparent conductive film and a preparation method and application thereof. The heterogeneous 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, two adjacent layers of transparent conductive films are made of different materials, and two non-adjacent layers of transparent conductive films are made of the same or different materials. The heterogeneous composite transparent conductive film disclosed by the invention has excellent performance in the aspects of cracking resistance and film-substrate binding force of the surface of a substrate which is not resistant to temperature, and the 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 specifically relates to a heterogeneous 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, mainly including oxide film system, metal film system, graphene film system and polymer film system. The metal film system has low resistivity but relatively poor transmittance, and the graphene film system also has the problem of poor balance between transmittance and surface resistance. Transparent conductive oxide film system has high transmittance and electrical conductivity, and is widely used in various fields of industrialization at this stage, including displays, solar cells, light-emitting diodes, electrochromic glass and electric heating glass. Transparent conductive oxide thin film materials include indium tin oxide (ITO), aluminum or gallium doped zinc oxide (AZO or GZO), indium zinc oxide (IZO), antimony or fluorine doped tin oxide (ATO or FTO), etc.

[0003] In actual industrial production, different application scenarios have specific performance requirements for transparent conductive films, such as room temperature preparation, thermal stability, chemical stability, moisture and heat stability, and surface work function. Transparent conductive oxide films prepared on the surface of organic substrates such as plexiglass or polycarbonate can be used for electrically heated glass such as airplanes or high-speed railways. However, the characteristics and surface valence bond structure of the organic substrate itself are significantly different from those of the transparent conductive oxide film, which puts higher requirements on the preparation process of transparent conductive films. For example, the low heat resistance temperature of the organic substrate requires that the transparent conductive film be prepared at a lower temperature (less than 80°C) or at room temperature. The thermal expansion coefficient of the organic substrate is significantly different from that of the transparent conductive oxide, which can easily cause problems such as film cracking or shedding.

[0004] The present invention is proposed to improve the film-base bonding strength and heat cracking resistance temperature of a transparent conductive oxide film on the surface of an organic substrate. Summary of the invention

[0005] The main purpose of the present invention is to propose a heterogeneous composite transparent conductive film and its preparation method and application. The heterogeneous composite transparent conductive film in the present invention has excellent performance in anti-cracking on the surface of heat-sensitive substrates and film-substrate bonding strength, 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 heterogeneous composite transparent conductive film, which includes a plurality of transparent conductive films stacked in sequence on at least one side of a substrate, wherein the materials of the two adjacent transparent conductive films are different, and the materials of the two non-adjacent transparent conductive films are the same or different.

[0008] In some embodiments of the present invention, the material of the heterogeneous composite transparent conductive film is selected from at least two 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 substrate is selected from one of organic glass, polycarbonate glass, polyethylene terephthalate substrate PET, and polyimide PI substrate.

[0010] In some embodiments of the present invention, the square resistance of the heterogeneous composite transparent conductive film is 2Ω / □ to 20Ω / □.

[0011] In some embodiments of the present invention, the adhesion of the heterogeneous composite transparent conductive film reaches level 0.

[0012] In some embodiments of the present invention, the heterogeneous 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.

[0013] In some embodiments of the present invention, the total thickness of the multi-layer transparent conductive film is 200 nm to 1000 nm.

[0014] In some embodiments of the present invention, the thickness of a single layer of the transparent conductive film is 30 nm to 600 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] The second aspect of the present invention provides a method for preparing the above-mentioned heterogeneous 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 materials of the two adjacent transparent conductive films are different, and the materials of the two non-adjacent transparent conductive films are the same or different.

[0018] 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 60mm~300mm, the argon flow rate is 10sccm~200sccm, and the oxygen flow rate is 1sccm~50sccm.

[0019] 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 is not less than 5.0×10 -3 Pa.

[0020] In some embodiments of the present invention, the process parameters for forming two layers of the transparent conductive film of the same material are the same or different;

[0021] A third aspect of the present invention provides an application of the above-mentioned heterogeneous composite transparent conductive film or the heterogeneous composite transparent conductive film prepared by the above-mentioned preparation method in flexible solar cells, flexible displays, electrically heated glass and transparent parts in the cockpit.

[0022] Compared with the prior art, the present invention achieves the following technical effects:

[0023] 1. The heterogeneous composite transparent conductive film in the present invention has excellent anti-cracking performance and film-base bonding strength on the surface of the heat-sensitive substrate, which solves the problems of easy cracking, film shedding and poor environmental resistance of the transparent conductive film during the preparation process or subsequent use, thereby expanding the engineering application of the transparent conductive film in the corresponding devices.

[0024] 2. The crack resistance temperature of the heterogeneous composite transparent conductive film on organic glass and polycarbonate glass substrates of the present invention is above 90°C for more than 6 hours, and the adhesion reaches level 0.

[0025] 3. The heterogeneous composite transparent conductive film of the present invention regulates the normal columnar growth structure of the film by setting multiple layers of transparent conductive films of different materials, which is beneficial to optimize the internal stress of the composite transparent conductive film, thereby improving the anti-cracking performance and environmental resistance of the composite transparent conductive film.

[0026] 4. The heterogeneous composite transparent conductive film in the present invention optimizes the film material and coating process to adjust the stress distribution of the film layer, improve the film bonding strength between the conductive film and the substrate, the crack resistance and the environmental resistance, and meet the actual application requirements without affecting the conductivity.

[0027] 5. The heterogeneous 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] 6. The present invention obtains a heterogeneous composite transparent conductive film with good photoelectric performance, high film-base bonding strength and resistance to high-temperature cracking by selecting a suitable transparent conductive oxide material to match with an organic substrate.

[0029] 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

[0030] 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:

[0031] Figure 1 is a schematic cross-sectional view of the heterogeneous composite transparent conductive film prepared in Example 1;

[0032] Figure 2 Schematic diagram of the cross section of the heterogeneous composite transparent conductive film prepared in Example 2.

[0033] Reference numerals

[0034] 100, substrate; 200, first transparent conductive film layer; 300, second transparent conductive film layer; 400, third transparent conductive film layer; 500, fourth transparent conductive film layer; 600, fifth transparent conductive film layer. DETAILED DESCRIPTION

[0035] 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.

[0036] 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 drawings and any variations thereof are intended to cover non-exclusive inclusions.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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).

[0041] 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 oxide films are prone to problems such as film cracking and film shedding, which can cause device damage. Current research is mainly focused on how to improve the shortcomings of film cracking and weak bonding by optimizing the conventional process parameters of transparent conductive films or adding other multilayer non-conductive thin film materials. 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.

[0042] To this end, the present invention provides a heterogeneous composite transparent conductive film and a preparation method thereof to solve the problems of film cracking, film shedding and poor environmental resistance of transparent conductive oxide films in engineering applications.

[0043] On one hand, the present invention provides a heterogeneous composite transparent conductive film, which includes a plurality of transparent conductive films stacked in sequence on at least one side of a substrate, wherein the materials of two adjacent transparent conductive films are different, and the materials of two non-adjacent transparent conductive films are the same or different.

[0044] The heterogeneous composite transparent conductive film in the present invention regulates the normal columnar growth of the film by setting a multi-layer transparent conductive film structure of different materials, which is beneficial to optimize the internal stress of the transparent conductive film, make it match other substrate materials, and improve the film layer bonding strength and environmental resistance such as resistance to heating cracking.

[0045] In an embodiment of the present invention, the sheet resistance of the heterogeneous composite transparent conductive film is 2Ω / □ to 20Ω / □. For example, the sheet resistance may be 13Ω / □ to 20Ω / □. Exemplarily, the sheet resistance may be one of 2Ω / □, 3Ω / □, 4Ω / □, 5Ω / □, 6Ω / □, 7Ω / □, 8Ω / □, 9Ω / □, 10Ω / □, 11Ω / □, 12Ω / □, 13Ω / □, 13.2Ω / □, 13.4Ω / □, 14Ω / □, 15Ω / □, 16Ω / □, 17Ω / □, 18Ω / □, 19Ω / □, 20Ω / □ or any value that satisfies the above range.

[0046] In the embodiment of the present invention, the adhesion of the heterogeneous composite transparent conductive film is level 0, achieving a better film system bonding force.

[0047] In some embodiments of the present invention, for organic glass substrates or polycarbonate glass substrates, the crack resistance temperature of the composite transparent conductive film is above 90° C. and the crack resistance time is above 6 hours.

[0048] 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.

[0049] In some embodiments of the present invention, the material of the heterogeneous composite transparent conductive film may be selected from at least two of indium tin oxide, indium zinc oxide, zinc oxide, zinc aluminum oxide, zinc gallium oxide, zinc oxide and indium gallium zinc oxide.

[0050] In some embodiments of the present invention, the total number of layers of the 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 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.

[0051] 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.

[0052] In some embodiments of the present invention, the thickness of each layer of transparent conductive film may be the same or different.

[0053] 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.

[0054] On the other hand, the present invention also provides a method for preparing a heterogeneous composite transparent conductive film, the key of which is to combine at least two transparent conductive oxide film materials according to the designed film system scheme, and adjust the coating process parameters to obtain the film layer by layer. Specifically, the film material is deposited layer by layer on the surface of the substrate by a magnetron sputtering process to obtain a heterogeneous composite transparent conductive film. Among them, the materials of the two adjacent transparent conductive films are the same, and the materials of the two non-adjacent transparent conductive films are the same or different.

[0055] 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 layer on the substrate, and the background vacuum is not less than 5.0×10 -3 Pa.

[0056] The method for preparing the heterogeneous composite transparent conductive film of the present invention is carried out according to the following steps.

[0057] (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.

[0058] (2) Confirming the target material corresponding to the first layer of transparent conductive film, and completing the preparation of the first layer of transparent conductive film according to the set coating process parameters.

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

[0060] (4) Referring to the above steps, the remaining layers of transparent conductive film 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 2The coating gas pressure is 0.01Pa~0.5Pa, the target-substrate distance is 60mm~300mm, the working gases are argon and oxygen, and the argon flow rate is 10sccm~200sccm. For example, the argon flow rate can be one of 10sccm, 20sccm, 30sccm, 40sccm, 50sccm, 60sccm, 70sccm, 80sccm, 90sccm, 100sccm, 110sccm, 120sccm, 130sccm, 140sccm, 150sccm, 160sccm, 170sccm, 180sccm, 190sccm, 200sccm or any value that meets 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.

[0062] In some embodiments of the present invention, the coating gas pressure may be 0.01Pa to 0.5Pa. For example, the coating gas pressure may be one of 0.01Pa, 0.02Pa, 0.05Pa, 0.08Pa, 0.1Pa, 0.2Pa, 0.3Pa, 0.4Pa, 0.5Pa or any value satisfying the above range.

[0063] In some embodiments of the present invention, the target-substrate distance can be 60 mm to 300 mm. Exemplarily, the target-substrate distance can be one of 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.

[0064] 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 , 1W / cm 2 , 2W / cm 2 、3W / cm 2, 4W / cm 2 , 5W / cm 2 or any value that satisfies the above range.

[0065] In some embodiments of the present invention, two adjacent transparent conductive films are made of different materials, and non-adjacent transparent conductive films are allowed to use the same transparent conductive film material. For example, the first transparent conductive film and the third transparent conductive film are allowed to be made of the same film material.

[0066] In some embodiments of the present invention, a multi-layer transparent conductive film is prepared layer by layer using different process parameters (eg, process parameter 1, process parameter 2, process parameter 3, and so on).

[0067] In some embodiments of the present invention, process parameters for forming two film layers of the same material are the same or different.

[0068] In some embodiments of the present invention, the material of the transparent conductive film is selected from but not limited to indium tin oxide (ITO), indium zinc oxide (IZO), aluminum zinc oxide (AZO), gallium zinc oxide (GZO), zinc oxide (ZnO) and indium gallium zinc oxide (IGZO).

[0069] On the other hand, the present invention provides the above-mentioned heterogeneous composite transparent conductive film or the heterogeneous composite transparent conductive film prepared by the above-mentioned preparation method, which is applied to an environment where high requirements are placed on the crack resistance and film adhesion of the transparent conductive film, such as in flexible solar cells, flexible displays, electrically heated glass, and transparent parts in the cockpit.

[0070] The heterogeneous composite transparent conductive film in the present invention can optimize the film layer bonding strength by utilizing the characteristics of different transparent conductive oxides, and realize the high anti-cracking temperature and film-base bonding strength of the composite transparent conductive film by optimizing the stress of the transparent conductive film itself, thereby expanding the engineering application of transparent conductive films in corresponding devices.

[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 heterogeneous composite transparent conductive film, and the preparation method of the heterogeneous composite transparent conductive film is as follows:

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

[0075] (2) The first layer of transparent conductive film 200 is plated on the organic glass, and the ITO target is selected. The coating power density of the ITO target is set to 3.5 W / cm 2 , the coating 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 10 sccm, and the thickness of the first layer of transparent conductive film 200 is 90 nm.

[0076] (3) After the first layer of transparent conductive film 200 is plated, the ITO target is replaced with an IZO target, and the coating power density of the IZO target is set to 3.0 W / cm 2 , the coating pressure is 0.1 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 coating of the second layer of transparent conductive film 300 is completed. The thickness of the second layer of transparent conductive film 300 is 90 nm.

[0077] (4) After the second layer of transparent conductive film 300 is plated, the target material is replaced with ITO target material again, and the coating power density of the ITO target material is set to 3.5 W / cm 2 , the coating 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 10sccm, and the coating of the third layer of transparent conductive film 400 is completed. The thickness of the third layer of transparent conductive film 400 is 90nm.

[0078] (5) After the third layer of transparent conductive film 400 is plated, the ITO target is replaced with an IZO target, and the coating power density of the IZO target is set to 3.0 W / cm 2 , the coating pressure is 0.1 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 coating of the fourth layer of transparent conductive film 500 is completed. The thickness of the fourth layer of transparent conductive film 500 is 90 nm.

[0079] (6) After the fourth layer of transparent conductive film 500 is plated, the target material is replaced with ITO target material again, and the coating power density of the ITO target material is set to 3.5 W / cm 2 , the coating 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 10 sccm, and the coating of the fifth layer of transparent conductive film 600 is completed. The thickness of the fifth layer of transparent conductive film 600 is 90 nm.

[0080] The ITO film layer and the IZO film layer are prepared alternately layer by layer to complete the preparation of the heterogeneous composite transparent conductive film.

[0081] Example 2

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

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

[0084] (2) The first layer of transparent conductive film 200 is plated on the organic glass, and the AZO target material is selected. The coating power density of the AZO target material is 3.0 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 16 sccm, the coating pressure is 0.15 Pa, and the thickness of the first layer of transparent conductive film 200 is 30 nm.

[0085] (2) After the first layer of transparent conductive film 200 is deposited, the AZO target is replaced with an IZO target. The coating power density of the IZO target is 3.0 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 14 sccm, and the plating of the second layer of transparent conductive film 300 is completed. The thickness of the second layer of transparent conductive film 300 is 500 nm.

[0086] (3) After the second layer of transparent conductive film 300 is deposited, the AZO target is replaced again, and the coating power density of the AZO target is set to 3.0 W / cm 2 , the coating gas pressure is adjusted to 0.15 Pa, the target substrate distance is 120 mm, the argon flow rate is set to 80 sccm, the oxygen flow rate is set to 16 sccm, and the preparation of the third layer of transparent conductive film 400 is completed. The thickness of the third layer of transparent conductive film 400 is 30 nm.

[0087] The AZO film and the IZO film are prepared alternately layer by layer, and the AZO film layer is prepared on the top layer and the bottom layer of the IZO film layer to complete the preparation of the heterogeneous composite transparent conductive film.

[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 background vacuum 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 3.5 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 10sccm, 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 background vacuum of 2.0×10 -3 Pa.

[0095] (2) Thin film coating was performed on organic glass, and IZO target was selected. The coating power density of IZO target was 3.0 W / cm 2 , the target substrate distance is 120mm, the argon flow rate is set to 80sccm, the oxygen flow rate is set to 14sccm, the coating gas pressure is 0.1Pa, and the film thickness is 560nm.

[0096] Performance Testing

[0097] Film adhesion test.

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

[0099] Sheet resistance test.

[0100] The sheet resistance of the heterogeneous composite transparent conductive film was tested using a surface resistivity meter based on the existing 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 heterogeneous 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 heterogeneous composite transparent conductive film provided by the present invention has excellent photoelectric properties, film-base 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 of transparent conductive films in engineering applications. It can be applied to use environments with high requirements for transparent conductive films, including flexible solar cells, flexible displays, electrically heated glass, and transparent parts in the cockpit.

[0106] In addition, the method of the present invention can expand the material of the transparent conductive film to a metal transparent conductive film with a sandwich structure. For example, when preparing an ITO / Au / ITO transparent conductive film, if the ITO film does not match well with other film materials, a layer of AZO transparent conductive film can be prepared again on the surface of the ITO film, thereby improving the adhesion of the film system.

[0107] 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 heterogeneous composite transparent conductive film, characterized in that: It comprises multiple layers of transparent conductive films stacked in sequence on at least one side of a substrate, wherein the materials of two adjacent layers of the transparent conductive films are different, and the materials of two non-adjacent layers of the transparent conductive films are the same or different.

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

3. The heterogeneous 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.

4. The heterogeneous composite transparent conductive film according to claim 1, characterized in that: The square resistance of the heterogeneous composite transparent conductive film is 2Ω / □ to 20Ω / □; Preferably, the adhesion of the heterogeneous composite transparent conductive film reaches level 0; Preferably, the heterogeneous 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.

5. The heterogeneous 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; Preferably, the total number of layers of the multi-layer transparent conductive film is no more than 10 layers, preferably 3 to 6 layers.

6. A method for preparing a heterogeneous composite transparent conductive film according to any one of claims 1 to 5, 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 two adjacent transparent conductive films are different, and the materials of the two non-adjacent transparent conductive films are the same or different.

7. The preparation method according to claim 6, characterized in that: 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.

8. The preparation method according to claim 6 or 7, characterized in that: The process parameters for forming two layers of the transparent conductive film made of the same material are the same or different, and the coating process parameters include coating power density, coating gas pressure, target-substrate distance, argon flow rate, and oxygen flow rate.

9. Use of the heterogeneous composite transparent conductive film according to any one of claims 1 to 5 or the heterogeneous composite transparent conductive film prepared by the preparation method according to any one of claims 6 to 8 in flexible solar cells, flexible displays, electrically heated glass and transparent parts of cockpits.

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