Crack method for preparing metal grid transparent electrode

Abstract

The invention relates to the technical field of transparent electrodes, in particular to a method for preparing a metal grid transparent electrode through a crack method, which comprises the following steps: S1, adhering a layer of SiO2 particles on a transparent substrate; s2, smearing the macromolecular solution on the surface of the transparent base material by using a rotary smearing method; s3, forming a layer of polymer film on the transparent substrate by the dried polymer solution, and generating cracks under the action of SiO2; s4, after the template is manufactured, metal is deposited in the crack area through methods such as vacuum evaporation and magnetron sputtering; and S5, the polymer template is taken out, the crack-shaped metal grid transparent electrode is obtained on the transparent base material, cracks are communicated with one another, the sizes of the cracks are controlled through heating, and the cracks are usually shrunk. Low cost and high reliability in the preparation process of the metal grid transparent electrode are achieved, the metal grid is not prone to disengagement in the using process, high optical transmittance and electric conductivity can be achieved, the stability of the metal grid transparent electrode is improved, and the service life of the metal grid transparent electrode is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of transparent electrodes, specifically to the preparation of metal grid transparent electrodes by the crack method. Background Art

[0002] The metal grid transparent electrode is a conductive material with high optical transmittance and low resistance, and is widely used in fields such as touch screens, solar cells, and displays. The metal grid transparent electrode with a mesh pattern has attracted great interest due to its high transmittance and low sheet resistance. Based on the patterned metal grid transparent electrode, its optoelectronic performance can be comparable to that of ITO; the raw material cost of ITO is high and it is brittle, while the storage amount of metals in nature is more than that of ITO, the price is low, and it is suitable for large-scale production. The preparation of metal grid transparent electrodes mostly depends on patterned templates, and the parameters of the templates determine the optoelectronic performance of the metal grid transparent electrodes.

[0003] In the laboratory, the crack method for preparing a pattern template is a common and cost-effective method. There has been a research team that attaches a gel film on a transparent substrate, forms microcracks through corresponding post-treatment, deposits metal in the cracks, and then removes the crack template to form corresponding metal grid nanowires to replace the crack network.

[0004] Considering the performance and manufacturing cost of the transparent electrode, metal grids and metal nanowires are one of the most promising transparent conductive film materials for engineering applications. Although the manufacturing cost of metal nanowires is relatively low, there are problems such as poor adhesion, poor thermal stability, and high contact resistance for the metal nanowires deposited on a rigid substrate, resulting in easy detachment of the metal grid during use, affecting the stability and lifespan of the device, and thus affecting the comprehensive performance of the rigid substrate metal nanowire transparent electrode. Therefore, we have developed a method for preparing metal grid transparent electrodes by the crack method. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for preparing metal grid transparent electrodes by the crack method, which not only realizes the low cost and high reliability in the preparation process of metal grid transparent electrodes, and the metal grid is not easily detached during use, but also can achieve high optical transmittance and conductivity, improving the stability and lifespan of the metal grid transparent electrode, so as to solve the problems raised in the above background art.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] A metal grid transparent electrode, comprising a substrate, which is used as a base for preparing the metal grid;

[0008] A polymer film, which is arranged on the top of the transparent base film, and cracks are provided on the polymer film for forming the metal grid;

[0009] The cracks are interconnected with each other;

[0010] A metal layer is disposed inside the crack to form a metal grid, and the metal layer is in direct contact with the substrate.

[0011] A crack method for preparing a metal grid transparent electrode includes the following steps: S1, attaching a layer of SiO2 particles to a transparent substrate;

[0012] S2, applying a polymer solution onto the surface of the transparent substrate by spin coating;

[0013] S3, after drying, the polymer solution forms a polymer film on the transparent substrate, and cracks are generated under the action of SiO2;

[0014] S4, after making a template, depositing metal in the crack region by methods such as vacuum evaporation and magnetron sputtering;

[0015] S5, removing the polymer template, and obtaining a crack-shaped metal grid transparent electrode on the transparent substrate.

[0016] As a further solution of the present invention, the size of the crack is controlled by heating, which is usually used to narrow the crack.

[0017] As a further solution of the present invention, the material is heated to the glass transition temperature and maintained for 5 minutes, and the polymer chains in the material move, strengthening the adhesion between the material and the substrate.

[0018] As a further solution of the present invention, the polymer solution is a solution of PMMA dissolved in chloroform or PS dissolved in chloroform.

[0019] As a further solution of the present invention, the concentration of the polymer solution is generally 20 mg / mL - 30 mg / mL, making it difficult to form cracks, the film will not be too thick, the cracks will not penetrate to the bottom, and the film is not easily warped.

[0020] As a further solution of the present invention, the transparent substrate is transparent glass.

[0021] As a further solution of the present invention, the evaporated metal is one of gold, silver, copper, zinc, chromium, and aluminum.

[0022] As a further solution of the present invention, the chloroform is a phase separation inducer.

[0023] As a further solution of the present invention, in step S5, the polymer layer is dissolved and removed by a polymer solvent, and then washed successively with ethanol and deionized water.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] The metal grid transparent electrode prepared by the crack method includes: S1, attaching a layer of SiO2 particles on a transparent substrate; S2, applying a polymer solution on the surface of the transparent substrate by spin coating; S3, after drying, the polymer solution forms a polymer film on the transparent substrate, and cracks are generated under the action of SiO2; S4, after making a template, depositing metal in the crack area by methods such as vacuum evaporation and magnetron sputtering; S5, removing the polymer template, and obtaining a crack-shaped metal grid transparent electrode on the transparent substrate. It not only realizes the low cost and high reliability in the preparation process of the metal grid transparent electrode, and the metal grid is not easy to detach during use, but also can achieve high optical transmittance and conductivity, improving the stability and service life of the metal grid transparent electrode. Brief Description of the Drawings

[0026] Figure 1 It is a schematic structural diagram of the metal grid transparent electrode prepared by the crack method. Detailed Embodiment

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying 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. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0028] Please refer to Figure 1 , the present invention provides a technical solution:

[0029] A metal grid transparent electrode includes a substrate, which is used as a base for preparing the metal grid;

[0030] A polymer film is provided on the top of the transparent base film, and cracks are provided on the polymer film for forming the metal grid;

[0031] The cracks are interconnected with each other;

[0032] A metal layer is arranged inside the cracks to form a metal grid, and the metal layer is in direct contact with the substrate

[0033] The method for preparing the metal grid transparent electrode by the crack method includes the following steps: S1, attaching a layer of SiO2 particles on a transparent substrate;

[0034] The SiO2 particles have good rigidity, which can improve the reliability and use effect of the transparent substrate;

[0035] The transparent substrate is transparent glass, which ensures the light transmittance of the substrate and improves the preparation effect;

[0036] S2. Apply the polymer solution onto the surface of the transparent substrate using the spin coating method. The polymer solution is a solution of PMMA dissolved in chloroform or PS dissolved in chloroform. For PS in chloroform, it is easily soluble and the experimental conditions are relatively simple.

[0037] For PMMA in chloroform, it can be dissolved, but additional measures such as heating, stirring, or extending the dissolution time may be required to ensure complete dissolution.

[0038] The concentration of the polymer solution is generally 20 mg / mL - 30 mg / mL, which makes it less difficult to form cracks, the film is not too thick, the cracks do not penetrate the bottom, and the film is not easily warped.

[0039] If the concentration of the polymer solution exceeds this range, it is very difficult to form cracks, the film is too thick, and the cracks do not penetrate the bottom.

[0040] If the concentration of the polymer solution is lower than this range, the film is easily warped and cannot be used as a template.

[0041] S3. After drying, the polymer solution forms a polymer film on the transparent substrate, and cracks are generated under the action of SiO2.

[0042] The cracks are interconnected with each other.

[0043] The size of the cracks is controlled by heating, which is usually used to narrow the cracks.

[0044] S4. After making the template, deposit metal in the crack area by methods such as vacuum evaporation and magnetron sputtering.

[0045] The evaporated metal is one of gold, silver, copper, zinc, chromium, and aluminum, and aluminum has the best effect. Vacuum evaporation of metal thin films is a new process in which metal is evaporated on the surface of a thin film substrate under vacuum conditions to form a composite thin film. Coating a very thin layer of metallic aluminum on the surface of a plastic film or paper (single-sided or double-sided) makes it a metallized film, which is widely used to replace aluminum foil composites such as aluminum foil / plastic and aluminum foil / paper.

[0046] S5. Remove the polymer template, and a crack-shaped metal grid transparent electrode is obtained on the transparent substrate.

[0047] Heat the material to the glass transition temperature and keep it for 5 minutes. The polymer chains in the material move, strengthening the adhesion between the material and the substrate.

[0048] In step S5, the polymer layer is dissolved and removed using a polymer solvent, and then washed successively with ethanol and deionized water.

[0049] Although the manufacturing cost of metal nanowires is relatively low, there are problems such as poor adhesion, poor thermal stability, and high contact resistance in the deposition of metal nanowires on a rigid substrate, resulting in easy detachment of the metal grid during use, affecting the stability and lifespan of the device, and thus affecting the comprehensive performance of the rigid substrate metal nanowire transparent electrode. However, the present invention not only achieves low cost and high reliability in the preparation process of the metal grid transparent electrode, and the metal grid is not easily detached during use, but also can achieve high optical transmittance and conductivity, improving the stability and lifespan of the metal grid transparent electrode.

[0050] 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. A metal grid transparent electrode, characterized in that: It includes a substrate used as a base for preparing a metal grid; A polymer film is disposed on the top of the transparent base film, and cracks are disposed on the polymer film to form a metal grid; The cracks are interconnected; The metal layer is arranged inside the crack and forms a metal grid, and the metal layer is in direct contact with the substrate.

2. A crack method for preparing a metal grid transparent electrode, applicable to the metal grid transparent electrode according to claim 1, characterized in that: The following steps are involved: S1, attaching a layer of SiO2 particles on a transparent substrate; S2, applying the polymer solution on the surface of the transparent substrate using a spin coating method; S3, the dried polymer solution forms a polymer film on the transparent substrate, and cracks are generated under the action of SiO2; S4, after the template is prepared, metal is deposited in the crack area by vacuum evaporation, magnetron sputtering, etc.; S5, taking out the polymer template, and obtaining a crack-shaped metal grid transparent electrode on the transparent substrate.

3. The crack method for preparing a metal grid transparent electrode according to claim 2, characterized in that: The size of the crack is controlled by applying heat, usually to shrink the crack.

4. The crack method for preparing a metal grid transparent electrode according to claim 3, characterized in that: The material is heated to the glass transition temperature for 5 minutes, and the polymer chains in the material move, strengthening the adhesion between the material and the substrate.

5. The crack method for preparing a metal grid transparent electrode according to claim 4, characterized in that: The polymer solution is a solution of PMMA dissolved in chloroform or PS dissolved in chloroform.

6. The crack method for preparing a metal grid transparent electrode according to claim 5, characterized in that: The concentration of the polymer solution is generally 20mg / mL-30mg / mL, which makes it less difficult for cracks to form, the film will not be too thick, the cracks will penetrate the bottom, and the film will not easily warp.

7. The crack method for preparing a metal grid transparent electrode according to claim 6, characterized in that: The transparent substrate is transparent glass.

8. The crack method for preparing a metal grid transparent electrode according to claim 7, characterized in that: The evaporated metal is one of gold, silver, copper, zinc, chromium and aluminum.

9. The crack method for preparing a metal grid transparent electrode according to claim 8, characterized in that: The chloroform is a phase separation inducing agent.

10. The crack method for preparing a metal grid transparent electrode according to claim 9, characterized in that: In the step S5, a polymer solvent is used to dissolve and remove the polymer layer, and ethanol and deionized water are used for washing in sequence.

Images