Metal grid transparent electrode prepared by cracking net-shaped grooves

Abstract

The invention discloses a metal grid transparent electrode prepared by a cracked reticular groove, and the preparation method of the transparent electrode comprises the following steps: S1, coating the surface of a transparent substrate with a tannic acid-ovalbumin composite gel film, and inducing the gel film to crack through solvent evaporation to form the reticular groove; s2, ion beam etching is carried out on the net-shaped groove, and residual impurities in the groove are removed; s3, depositing metal in the etched groove to form a conductive grid; s4, removing the residual gel film to obtain a metal grid transparent electrode; the line width, spacing and density of cracks can be accurately controlled by adjusting the molar ratio, humidity and temperature conditions of tannic acid and ovalbumin, so that a uniform metal grid structure is prepared, the line width of a metal grid is uniform, node connection is good, the conductivity and light transmission of an electrode are effectively improved, a complex mask or a high-precision mold is not needed, and the production cost is reduced. And the production cost is reduced, large-scale production is easy to realize, and the method is particularly suitable for flexible substrates.

Description

Technical Field

[0001] The present invention relates to the technical field of transparent electrodes, specifically to the preparation of metal grid transparent electrodes with cracked reticular grooves. Background Art

[0002] Metal grid transparent electrodes are widely used in flexible electronics, display devices, photovoltaics and other fields due to their high conductivity, high light transmittance and flexible compatibility. Currently, the mainstream preparation technologies rely on patterning templates, such as photolithography, nanoimprinting, etc., to form micro-nano structures on the substrate through precise masks or molds, and guide metal deposition to form a conductive network. In recent years, the metal grid preparation technology based on crack templates has attracted much attention due to its low cost and simple process. For example, a crack network is formed by inducing solvent evaporation or stress release in a gel film, such as a polymer film, and this is used as a template to fill the metal. However, the existing crack template method still has the following problems:

[0003] (1) Traditional template methods require complex masks or high-precision molds, which are costly and difficult to meet the large-scale production requirements of flexible substrates;

[0004] (2) In the existing crack induction method, due to the inability to accurately control the crack network, the line width of the metal grid is uneven and the nodes are fractured, significantly reducing the conductivity and light transmittance uniformity of the electrode;

[0005] (3) Post-treatment steps such as chemical etching or high-temperature annealing are likely to damage the flexible substrate or the metal structure, and residual impurities, such as organic substances and etching by-products, affect the long-term stability of the electrode. Summary of the Invention

[0006] The purpose of the present invention is to provide a metal grid transparent electrode prepared with cracked reticular grooves to solve the problems raised in the above background art.

[0007] To achieve the above purpose, the present invention provides the following technical solution: A metal grid transparent electrode prepared with cracked reticular grooves, and the preparation method of this transparent electrode includes the following steps:

[0008] S1: Coat a tannic acid-ovalbumin composite gel film on the surface of a transparent substrate, and induce the gel film to crack to form reticular grooves through solvent evaporation;

[0009] Among them, the preparation method of the tannic acid-ovalbumin composite gel film includes the following steps:

[0010] S11: Dissolve tannic acid powder in deionized water to prepare a tannic acid solution with a concentration of 3-7%;

[0011] S12: Dissolve ovalbumin powder in deionized water, centrifuge at 8000 r / min for 8-12 min, and take the supernatant to prepare an ovalbumin solution with a concentration of 3-7%;

[0012] S13: Mix the tannic acid solution and the ovalbumin solution in a volume ratio of 1:1 to form a composite gel precursor solution.

[0013] S2: Perform ion beam etching on the reticulated grooves to remove the residual impurities in the grooves;

[0014] S3: Deposit metal in the etched grooves to form a conductive grid;

[0015] S4: Remove the residual gel film to obtain a metal grid transparent electrode.

[0016] Preferably, the coating method is quantitative coating with a pipette gun. After coating, it is left standing in an environment with a humidity of 30 - 60% and a temperature of 20 - 25°C for 8 - 16 h to form a uniform crack network.

[0017] Preferably, the ion beam etching gas is O2, the gas flow rate is 10 - 30 sccm, the etching power is 200 W, the etching time is 1 - 2 min, the etching depth is 100 - 200 nm, and the etching rate is 120 nm / min.

[0018] Preferably, the metal deposition is carried out by magnetron sputtering. The sputtered metal is silver, copper, gold or their alloy, the sputtering thickness is 50 - 300 nm, the sputtering vacuum degree is not greater than 5×10 -3 Pa, and the sputtering power is 100 - 300 W.

[0019] Preferably, the specific method for removing the residual gel film: Immerse the sample after metal deposition in deionized water for 30 min, and then perform ultrasonic cleaning for 5 - 10 min to remove all organic templates.

[0020] Preferably, the transparent substrate is a flexible polymer material, such as polyethylene terephthalate, polyethylene naphthalate or polyimide, with a thickness of 50 - 200 μm.

[0021] Preferably, the line width of the crack network is 1 - 10 μm, the spacing is 50 - 200 μm, and the crack density is 10 - 50 lines / mm 2 .

[0022] Preferably, the electrode has a bionic crack network structure, the metal line width is 1 - 10 μm, and the grid light transmittance and sheet resistance satisfy the relationship: T = 100% - 0.5R -1 ,

[0023] where T is the light transmittance and R is the sheet resistance, with the unit of Ω / sq.

[0024] Preferably, the thickness of the composite gel film is 5 - 20 μm, and the surface roughness Ra after film formation is not greater than 50 nm.

[0025] Preferably, the sheet resistance of the metal mesh transparent electrode is not greater than 20 Ω / sq, the wavelength is 550 nm, the light transmittance is not less than 90%, and the haze is not greater than 3%.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] 1. By adjusting the molar ratio of tannic acid to ovalbumin, humidity, and temperature conditions, the present invention can precisely control the line width, spacing, and density of the cracks, thereby preparing a uniform metal mesh structure. The metal mesh has a uniform line width and good node connection, effectively improving the electrical conductivity and light transmittance of the electrode.

[0028] 2. The present invention does not require complex masks or high-precision molds, reducing production costs and being easy to achieve large-scale production. It is especially suitable for flexible substrates. Using a flexible polymer material as the substrate can balance the flexibility and mechanical strength of the electrode.

[0029] 3. Through ion beam etching and magnetron sputtering technologies, the present invention effectively removes residual impurities in the grooves, reduces the surface carbon content, improves the bonding force between the metal mesh and the substrate, ensures the long-term stability of the electrode, and by optimizing the etching and sputtering parameters, avoids over-etching damage to the substrate and ensures the integrity of the substrate and the metal mesh. Description of the Drawings

[0030] Figure 1 It is a schematic structural diagram of the process for preparing a metal mesh transparent electrode with a cracked reticular groove according to the present invention.

[0031] Figure 2 It is a flowchart of the method for preparing a metal mesh transparent electrode with a cracked reticular groove according to the present invention. Detailed Embodiments

[0032] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0033] Please refer to Figures 1 to 2 , the present invention provides a technical solution: a method for preparing a metal mesh transparent electrode with a cracked reticular groove, and the preparation method of the transparent electrode includes the following steps:

[0034] S1: Coating a tannic acid-ovalbumin composite gel film on the surface of a transparent substrate, and inducing the gel film to crack through solvent evaporation to form a reticular groove; the transparent substrate is a flexible polymer material, using polyethylene terephthalate, polyethylene naphthalate, or polyimide, with a thickness of 50-200 μm, providing a balance of flexibility and mechanical strength.

[0035] The coating method is quantitative coating with a pipette gun, using 1 ml / substrate. After coating, it is left standing in an environment with a humidity of 30 - 60%. When the humidity is lower than 30%, the cracks are too dense, and when it is higher than 60%, the film-forming speed is too slow. It is left standing for 8 - 16 h in an environment with a temperature of 20 - 25 °C to form a uniform cracked network. The line width of the cracked network is 1 - 10 μm, the spacing is 50 - 200 μm, and the crack density is 10 - 50 cracks / mm 2 。

[0036] The evaporation of water molecules causes the volume of the gel film to shrink. When the internal stress accumulation exceeds the film strength threshold, crack propagation occurs. The crosslinking density is controlled by adjusting the molar ratio of tannic acid to ovalbumin. The line width of 1 - 10 μm is determined by the shrinkage stress of the gel film, and the spacing of 50 - 200 μm is regulated by the solvent evaporation rate.

[0037] Among them, the preparation method of the tannic acid-ovalbumin composite gel film includes the following steps:

[0038] S11: Dissolve tannic acid powder in deionized water to prepare a tannic acid solution with a concentration of 3 - 7%; purify the deionized water to avoid impurity interference with the crosslinking reaction. During the dissolution process, stir magnetically until the solution is clear, and then use a 0.22 μm filter membrane to remove undissolved particles.

[0039] The cracking process needs to be monitored in real time, such as with an optical microscope, and the crack density is 10 - 50 cracks / mm 2 By adjusting the humidity gradient, such as reducing the humidity in stages, a uniform distribution can be achieved.

[0040] S12: After dissolving ovalbumin powder in deionized water, centrifuge at 8000 r / min for 8 - 12 min, and take the supernatant to prepare an ovalbumin solution with a concentration of 3 - 7%; centrifuge to separate insoluble impurities in ovalbumin, such as lipids and polysaccharides, to ensure the clarity of the solution; the ovalbumin solution provides sufficient film-forming properties. If the concentration is too high, the brittleness of the gel film increases, and random fractures are likely to occur.

[0041] S13: Mix the tannic acid solution and the ovalbumin solution in a volume ratio of 1:1 to form a composite gel precursor solution.

[0042] The thickness of the composite gel film is 5 - 20 μm, and the surface roughness Ra after film formation is not greater than 50 nm. After mixing, ultrasonic treatment is required to remove air bubbles to avoid the formation of holes during film formation.

[0043] Tannic acid, as a polyphenolic crosslinking agent, forms hydrogen bonds and hydrophobic interactions with the amino groups of ovalbumin, regulating the mechanical strength and crack propagation behavior of the gel film. Ovalbumin, as a natural amphiphilic protein, forms a network structure through self-assembly, and the shrinkage stress generated during solvent evaporation induces cracking.

[0044] S2: Perform ion beam etching on the reticular grooves to remove residual impurities in the grooves; the ion beam etching gas is O2, the gas flow rate is 10 - 30 sccm, the etching power is 200 W, the etching time is 1 - 2 min, the etching depth is 100 - 200 nm, and the etching rate is 120 nm / min.

[0045] O2 ion beam selectively etches residual gel fragments and contaminants in the grooves, reducing the surface carbon content. The etching depth of 100 - 200 nm ensures the minimization of contact resistance during metal filling, while avoiding over-etching damage to the substrate; argon pre-cleaning before etching removes surface adsorbates, and the etching angle is 30 - 60° to enhance the metal adhesion on the sidewalls of the grooves.

[0046] S3: Deposit metal in the etched grooves to form a conductive grid; the metal deposition uses magnetron sputtering method, the sputtered metal is silver, copper, gold or their alloys, the sputtering thickness is 50 - 300 nm, the sputtering vacuum degree is not greater than 5×10 -3 Pa, the sputtering power is 100 - 300 W, the vacuum degree reduces oxidation, the power adjusts the kinetic energy of metal particles, avoiding thermal damage to the substrate. The substrate is preheated to 60 - 80 °C before sputtering to enhance the interfacial bonding force between the metal and the grooves.

[0047] S4: Remove the residual gel film to obtain a metal grid transparent electrode.

[0048] The specific method for removing the residual gel film: Immerse the sample after metal deposition in deionized water for 30 min, then ultrasonically clean for 5 - 10 min to remove all organic templates.

[0049] The tannic acid - ovalbumin composite film swells and disintegrates in water, and ultrasonic assistance is used to thoroughly remove the residue, avoiding mechanical peeling damage to the metal grid.

[0050] Dry with nitrogen after soaking in deionized water to prevent water marks from remaining and affecting the surface flatness of the electrode.

[0051] The electrode has a bionic cracked network structure, the metal wire width is 1 - 10 μm, and the relationship between the grid light transmittance and the sheet resistance satisfies the formula: T = 100% - 0.5R -1 where T is the light transmittance, R is the sheet resistance, the unit is Ω / sq, the sheet resistance of the metal grid transparent electrode is not greater than 20 Ω / sq, the wavelength is 550 nm, the light transmittance is not less than 90%, and the haze is not greater than 3%.

[0052] Example 1:

[0053] Prepare a metal grid transparent electrode with cracked reticular grooves. The preparation method of this transparent electrode includes the following steps:

[0054] S1: Take 5 g of tannic acid powder and dissolve it in 100 ml of deionized water. Stir magnetically until the solution is clear, and then pass it through a 0.22 μm filter membrane to remove undissolved particles, obtaining a 5% tannic acid solution. Take 5 g of ovalbumin powder and dissolve it in 100 ml of deionized water. Centrifuge at 8000 r / min for 10 min, and take the supernatant and pass it through a 0.45 μm filter membrane to obtain a 5% ovalbumin solution. Mix the tannic acid solution and the ovalbumin solution in a volume ratio of 1:1, and perform ultrasonic treatment to eliminate air bubbles. Let it stand for 30 min to form a uniform composite gel precursor solution;

[0055] S2: Use a polyethylene terephthalate film as the substrate with a thickness of 100 μm and a light transmittance of 92%. Perform O2 plasma cleaning, and the contact angle decreases from 75° to 20°, enhancing hydrophilicity. Use a pipette to quantitatively coat 1 ml of the precursor solution on the surface of the PET, and let it stand in an environment with a humidity of 45% and a temperature of 23 °C for 12 h to form a gel film with a thickness of 10 μm;

[0056] S3: The evaporation of water molecules causes the volume of the film to shrink by 15%, and internal stress accumulates to form a uniform crack network with a line width of 3 - 5 μm, a spacing of 100 - 150 μm, and a density of 30 lines / mm 2 , through staged humidity reduction control, with a humidity of 50% in the first 4 h and reduced to 35% in the next 8 h. Observe the crack propagation under an optical microscope to ensure no cross - fracture or local aggregation;

[0057] S4: Perform argon plasma treatment with a power of 50 W for 5 min to remove surface adsorbates. The etching gas is O2 with a flow rate of 20 sccm, a power of 200 W, a time of 1.5 min, an etching depth of 150 nm, an etching rate of 120 nm / min, and an etching angle of 45°. Optimize the metal adhesion with the inclination angle of the groove side wall;

[0058] S5: The sputtering metal target is silver, the sputtering vacuum degree is 3×10 -3 Pa, the sputtering power is 200 W, the substrate preheating temperature is 70 °C, the sputtering time is 10 min, and the thickness of the metal layer is 150 nm;

[0059] S6: Immerse the specimen in deionized water for 30 min and perform ultrasonic cleaning at 40 kHz for 8 min to remove the gel residue.

[0060] Example Two:

[0061] Prepare a metal grid transparent electrode with a cracked mesh groove. The preparation method of this transparent electrode includes the following steps:

[0062] S1: Dissolve 5 g of tannic acid powder in 100 ml of deionized water, stir magnetically until the solution is clear, and filter through a 0.22 μm filter membrane to remove undissolved particles to obtain a 5% tannic acid solution; dissolve 7 g of ovalbumin powder in 100 ml of deionized water, centrifuge at 8000 r / min for 10 min, take the supernatant and filter through a 0.45 μm filter membrane to obtain a 7% ovalbumin solution; mix the tannic acid solution and the ovalbumin solution at a volume ratio of 1:1, ultrasonically treat to remove air bubbles, and let stand for 30 min to form a homogeneous composite gel precursor solution;

[0063] S2: Use a polyethylene terephthalate film as the substrate, with a thickness of 100 μm and a light transmittance of 92%. Perform O2 plasma cleaning, and the contact angle decreases from 75° to 20°, enhancing hydrophilicity. Use a pipette to quantitatively coat 1 ml of the precursor solution on the surface of the PET, and let it stand in an environment with a humidity of 50% and a temperature of 25 °C for 14 h to form a gel film with a thickness of 10 μm;

[0064] S3: The evaporation of water molecules causes the volume of the film to shrink by 15%, and internal stress accumulates to form a uniform crack network with a line width of 5 - 8 μm, a spacing of 80 - 120 μm, and a density of 30 lines / mm 2 , through staged humidity reduction control, the humidity is 50% in the first 4 h and drops to 35% in the next 8 h. Observe the crack propagation under an optical microscope to ensure no cross - fracture or local aggregation;

[0065] S4: Perform argon plasma treatment with a power of 50 W and a time of 5 min to remove surface adsorbates. The etching gas is O2, with a flow rate of 20 sccm, a power of 200 W, a time of 1.5 min, an etching depth of 150 nm, an etching rate of 120 nm / min, and an etching angle of 45°. Optimize the metal adhesion with the inclined angle of the groove sidewall;

[0066] S5: The sputtering metal target is copper, the sputtering vacuum degree is 3×10 -3 Pa, the sputtering power is 200 W, the substrate pre - heating temperature is 70 °C, the sputtering time is 10 min, and the thickness of the metal layer is 200 nm;

[0067] S6: Immerse the sample in deionized water for 30 min and ultrasonically clean at 40 kHz for 8 min to remove the gel residue.

[0068] Example 3:

[0069] Prepare a metal grid transparent electrode with a cracked reticular groove. The preparation method of this transparent electrode includes the following steps:

[0070] S1: Take 3 g of tannic acid powder and dissolve it in 100 ml of deionized water. Stir magnetically until the solution is clear. Pass it through a 0.22-μm filter membrane to remove undissolved particles, obtaining a 3% tannic acid solution. Take 5 g of ovalbumin powder and dissolve it in 100 ml of deionized water. Centrifuge at 8000 r / min for 10 min, and take the supernatant and pass it through a 0.45-μm filter membrane to obtain a 5% ovalbumin solution. Mix the tannic acid solution and the ovalbumin solution in a volume ratio of 1:1, and perform ultrasonic treatment to remove air bubbles. Let it stand for 30 min to form a homogeneous composite gel precursor solution.

[0071] S2: Use a polyimide film as the substrate with a thickness of 50 μm and a light transmittance of 88%. Perform O2 plasma cleaning, and the contact angle decreases from 75° to 20°, enhancing hydrophilicity. Use a pipette to quantitatively coat 1 ml of the precursor solution on the PET surface, and let it stand in an environment with a humidity of 45% and a temperature of 23 °C for 12 h to form a gel film with a thickness of 10 μm.

[0072] S3: The evaporation of water molecules causes the film volume to shrink by 15%, and internal stress accumulates to form a uniform crack network with a line width of 1 - 3 μm, a spacing of 50 - 80 μm, and a density of 30 lines / mm 2 , through staged humidity reduction control, the humidity is 50% in the first 4 h and then reduced to 35% in the next 8 h. Observe the crack propagation with an optical microscope to ensure no cross-breaking or local aggregation.

[0073] S4: Perform argon plasma treatment with a power of 50 W and a time of 5 min to remove surface adsorbents. The etching gas is O2 with a flow rate of 20 sccm, a power of 200 W, a time of 1.5 min, an etching depth of 150 nm, an etching rate of 120 nm / min, and an etching angle of 45°. Optimize the metal adhesion for the inclined angle of the groove sidewall.

[0074] S5: The sputtering metal target is a gold-silver alloy, the sputtering vacuum degree is 3×10 -3 Pa, the sputtering power is 200 W, the substrate preheating temperature is 70 °C, the sputtering time is 10 min, and the metal layer thickness is 80 nm.

[0075] S6: Immerse the sample in deionized water for 30 min and perform ultrasonic cleaning at 40 kHz for 8 min to remove the gel residue.

[0076] From what is described in Examples 1, 2, and 3, and by comparing with the preparation of metal grid electrodes by traditional photolithography, it can be obtained that for Example 1, the light transmittance is 92% at a wavelength of 550 nm, the haze is 2.5%, and the sheet resistance is 18 Ω / sq; after bending 1000 times with a curvature radius of 3 mm, the change rate of the sheet resistance is ≤8%; for Example 2, using a copper grid electrode reduces the cost, and the light transmittance and sheet resistance still meet the industrial standards of T≥85% and R≤25 Ω / sq; the ultra-fine line width of Example 3 realizes a high-resolution electrode, which is suitable for micro flexible displays.

[0077] By adjusting the molar ratio of tannic acid to ovalbumin, humidity, and temperature conditions, the present invention can precisely control the line width, spacing, and density of cracks, thereby preparing a uniform metal grid structure with uniform line width of the metal grid and good node connection, effectively improving the conductivity and light transmittance of the electrode; through ion beam etching and magnetron sputtering technologies, the residual impurities in the grooves are effectively removed, the surface carbon content is reduced, the bonding force between the metal grid and the substrate is improved, ensuring the long-term stability of the electrode, and by optimizing the etching and sputtering parameters, over-etching damage to the substrate is avoided, ensuring the integrity of the substrate and the metal grid; without the need for complex masks or high-precision molds, the production cost is reduced, and large-scale production is easily achieved, especially suitable for flexible substrates, using flexible polymer materials as the substrate to balance the flexibility and mechanical strength of the electrode.

[0078] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. The preparation method of a cracked network groove metal grid transparent electrode is characterized in that: The preparation method of the transparent electrode comprises the following steps: S1: Coating a tannic acid-ovalbumin composite gel film on the surface of a transparent substrate, and inducing the gel film to crack through solvent evaporation to form a reticular groove; Among them, the preparation method of the tannic acid-ovalbumin composite gel film comprises the following steps: S11: Dissolving tannic acid powder in deionized water to prepare a tannic acid solution with a concentration of 3-7%; S12: Dissolving ovalbumin powder in deionized water, centrifuging at 8000 r / min for 8-12 min, and taking the supernatant to prepare an ovalbumin solution with a concentration of 3-7%; S13: Mixing the tannic acid solution and the ovalbumin solution in a volume ratio of 1:1 to form a composite gel precursor solution. S2: Performing ion beam etching on the reticular groove to remove residual impurities in the groove; S3: Depositing a metal in the etched groove to form a conductive grid; S4: Removing the residual gel film to obtain a metal grid transparent electrode.

2. The method for preparing a cracked mesh groove metal grid transparent electrode according to claim 1, wherein: The coating method is quantitative coating with a pipette gun. After coating, it is left standing in an environment with a humidity of 30-60% and a temperature of 20-25 °C for 8-16 h to form a uniform cracking network.

3. The method for preparing a cracked mesh groove metal grid transparent electrode according to claim 1, wherein: The ion beam etching gas is O2, the gas flow rate is 10-30 sccm, the etching power is 200 W, the etching time is 1-2 min, the etching depth is 100-200 nm, and the etching rate is 120 nm / min.

4. The method for preparing a cracked network groove metal grid transparent electrode according to claim 1, wherein: The metal deposition is carried out by magnetron sputtering. The sputtered metal is silver, copper, gold or their alloy. The sputtering thickness is 50 - 300 nm, the sputtering vacuum degree is not more than 5×10 -3 Pa, and the sputtering power is 100 - 300 W.

5. The method for preparing a cracked mesh groove metal grid transparent electrode according to claim 1, wherein: The specific method for removing the residual gel film: Immersing the sample after metal deposition in deionized water for 30 min, and then performing ultrasonic cleaning for 5-10 min to remove all organic templates.

6. The method for preparing a cracked mesh groove metal grid transparent electrode according to claim 1, wherein: The transparent substrate is a flexible polymer material, using polyethylene terephthalate, polyethylene naphthalate or polyimide, with a thickness of 50-200 μm.

7. The method for preparing a cracked mesh groove metal grid transparent electrode according to claim 1, wherein: The line width of the crack network is 1 - 10 μm, the spacing is 50 - 200 μm, and the crack density is 10 - 50 cracks / mm 2 .

8. The method for preparing a cracked mesh groove metal grid transparent electrode according to claim 1, wherein: The electrode has a bionic crack network structure, the metal wire width is 1-10 μm, and the grid light transmittance and sheet resistance satisfy the relationship: T = 100% - 0.5R -1 , Where T is the transmittance and R is the sheet resistance, with the unit of Ω / sq.

9. The method for preparing a cracked mesh groove metal grid transparent electrode according to claim 1, wherein: The thickness of the composite gel film is 5-20 μm, and the surface roughness Ra after film formation is not greater than 50 nm.

10. The metal grid transparent electrode prepared by the cracked network grooves according to claim 1, wherein: The sheet resistance of the metal grid transparent electrode is not greater than 20 Ω / sq, the wavelength is 550 nm, the transmittance is not less than 90%, and the haze is not greater than 3%.

Images