Method for manufacturing a transparent electrode and transparent electrode

Abstract

The present application relates to a kind of transparent electrode preparation method and transparent electrode, by setting up microsphere with 20 nanometer diameter on substrate, and microsphere is handled by self-assembly, so that microsphere is evenly distributed on substrate, electrode material is covered on the substrate provided with microsphere, then the part of substrate and microsphere contact is not deposited with electrode material, so that higher light transmittance is obtained;At the same time, the thickness of the electrode material covered is 2-15 nanometers, while realizing high conductivity, the film thickness is reduced, the metal material is saved, and the transparent electrode is applied to small device with low weight requirement;The electrochromic device prepared by the technical scheme shown in the present application has a great improvement in the coloring response time compared with the electrochromic device prepared by ITO electrode, further improving the problem of slow response time of large-area electrochromic device.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optoelectronic applications, in particular to a transparent electrode preparation method and a transparent electrode. BACKGROUND

[0002] As a conductive and light-transmitting functional layer in thin-film optoelectronic devices, the transparent electrode directly affects the performance of the optoelectronic device and plays a crucial role in the fields of LED, flat panel display, solar photovoltaic, and electrochromic. The commonly used transparent electrode is mainly transparent conductive oxide such as indium tin oxide (ITO), but the ITO film is limited in its wide application in the field of optoelectronic devices due to the following three main reasons: (1) The ITO film has a large Young's modulus and poor mechanical properties, which limits its application in roll to roll low-cost production and flexible optoelectronic devices; (2) The ITO film has a low infrared light transmittance, and its light transmittance is even as low as 20% in the near-infrared (1000nm-2500nm) region, which limits its application in photovoltaic and electrochromic fields that require infrared light transmission; (3) The thickness of ITO is usually 100-200nm, and the conductivity of amorphous ITO is not high, so the thickness needs to be further increased to improve the conductivity of ITO, resulting in a high resistance of the ITO film electrode and making it impossible to realize real large-area preparation.

[0003] The raw material of the ultra-thin metal electrode is widely available in nature and has good flexibility. Metals such as gold, silver, and copper have excellent flexibility and high conductivity. Making a multi-layer metal electrode, increasing the contact conductivity, reducing the contact resistance (CN 106972069B), or directly preparing an ultra-thin metal electrode to increase the conductivity (CN 108258142 A), or using a double-layer film structure to deposit a layer of metal oxide on the ultra-thin metal layer to increase the light transmittance (CN 107393979A) is an effective research approach to solve the above problems of the transparent electrode.

[0004] In order to reduce the square resistance, the thickness of the ITO electrode can only be increased. Although the ultra-thin metal electrode has strong conductivity, its light transmittance is low. For the electrochromic field, high light transmittance and low square resistance of the electrode are essential conditions. The lower the square resistance, the faster the response of the electrochromic device, and the better the uniformity of color change; the higher the light transmittance, the better the modulation performance of the electrochromic device. The current metal electrode has the following problems: the transmittance decreases sharply when the film thickness increases, and the metal film has poor contact with the substrate. SUMMARY

[0005] In view of the above problems, the present application provides a transparent electrode preparation method and a transparent electrode, which solve the problem that the existing transparent electrode cannot meet the low sheet resistance and high light transmittance requirements in the field of electrochromism.

[0006] To achieve the above object, in a first aspect, the present application provides a transparent electrode preparation method, comprising:

[0007] Performing ultraviolet cleaning treatment on the substrate to improve the hydrophilicity of the substrate surface;

[0008] Performing self-assembly treatment on the substrate to make the microspheres distributed on the substrate surface in a first preset manner, and the diameter of the microspheres is 20 nanometers;

[0009] Covering the electrode material on the substrate, and the thickness of the electrode material is 2-15 nanometers;

[0010] Removing the microspheres on the substrate to obtain the transparent electrode.

[0011] In some embodiments, the method further comprises the following steps:

[0012] After the microspheres are distributed on the substrate surface in the first preset manner, performing plasma etching on the substrate to expose part of the substrate surface.

[0013] In some embodiments, the microspheres are polystyrene microspheres, and the substrate is a glass substrate, and covering the electrode material on the substrate comprises:

[0014] Performing low-temperature atomic layer deposition on the substrate to deposit the electrode material on the substrate to form a metal electrode;

[0015] Removing the microspheres on the substrate comprises:

[0016] Performing heating treatment on the substrate at 150°C for 15 minutes to remove the microspheres.

[0017] In some embodiments, the microspheres are silica microspheres, and the substrate is a calcium fluoride substrate or a barium sulfate substrate, and covering the electrode material on the substrate comprises:

[0018] Performing low-temperature atomic layer deposition on the substrate to deposit the electrode material on the substrate to form a metal electrode;

[0019] Or, performing vacuum evaporation on the substrate to deposit the electrode material on the substrate to form a metal electrode;

[0020] Or, performing magnetron sputtering on the substrate to deposit the electrode material on the substrate to form a metal electrode;

[0021] Or, performing vacuum ion plating on the substrate to deposit the electrode material on the substrate to form a metal electrode;

[0022] The microspheres on the substrate are removed, comprising:

[0023] The substrate is cleaned by a hydrofluoric acid solution to remove the microspheres.

[0024] In some embodiments, the electrode material is any one of silver, gold, zinc, copper, aluminum, and nickel.

[0025] In a second aspect, the present application provides a transparent electrode prepared according to the transparent electrode preparation method of the first aspect.

[0026] In a third aspect, the present application provides a transparent electrode preparation method, comprising:

[0027] The substrate is subjected to ultraviolet cleaning treatment to improve the hydrophilicity of the surface of the substrate;

[0028] Self-assembly treatment is performed on the substrate to make the microspheres be distributed on the surface of the substrate in a second preset manner, and the diameter of the microspheres is 40 nanometers;

[0029] The substrate is subjected to a heating treatment at 150°C for 5 minutes to make the microspheres decompose into hemispheres and be uniformly arranged on the substrate;

[0030] Low-temperature atomic layer deposition is performed on the substrate to make the electrode material be deposited on the substrate to form a metal electrode;

[0031] The substrate is subjected to a heating treatment at 150°C for 10 minutes to remove the microspheres to obtain a transparent electrode.

[0032] In some embodiments, the method further comprises the following steps:

[0033] After the microspheres are distributed on the surface of the substrate in the second preset manner, the substrate is subjected to plasma etching to expose part of the surface of the substrate.

[0034] In some embodiments, the microspheres are polystyrene microspheres.

[0035] In a fourth aspect, the present application further provides a transparent electrode prepared according to the transparent electrode preparation method of the third aspect.

[0036] Unlike existing technologies, the above-mentioned technical solution involves setting microspheres with a diameter of 20 nanometers on a substrate and performing self-assembly processing on the microspheres to ensure uniform distribution on the substrate. When electrode material is covered on the substrate with microspheres, no electrode material is deposited at the contact area between the substrate and the microspheres, thus achieving higher light transmittance. At the same time, the thickness of the covered electrode material is 2-15 nanometers, which reduces the film thickness while achieving high conductivity, saving metal materials and facilitating the application of transparent electrodes in small devices with low weight requirements. Electrochromic devices made using the transparent electrodes prepared by the technical solution shown in this application have a significantly improved color response time compared to electrochromic devices prepared using ITO electrodes, further improving the problem of slow response time in large-area electrochromic devices.

[0037] The above description of the invention is merely an overview of the technical solution of this application. In order to enable those skilled in the art to better understand the technical solution of this application and to implement it based on the description and drawings, and to make the above-mentioned objectives and other objectives, features and advantages of this application easier to understand, the following description is provided in conjunction with the specific embodiments and drawings of this application. Attached Figure Description

[0038] The accompanying drawings are only used to illustrate the principles, implementation methods, applications, features, and effects of specific embodiments of the present invention and other related contents, and should not be considered as limitations on this application.

[0039] Figure 1 This is a schematic diagram of the transparent electrode fabrication method steps described in the first exemplary embodiment;

[0040] Figure 2 A top view schematic diagram of the first preset arrangement of the microspheres in a specific embodiment;

[0041] Figure 3 for Figure 2 The front view;

[0042] Figure 4 for Figure 2 Top view diagram after removing the microspheres;

[0043] Figure 5 for Figure 4 The front view;

[0044] Figure 6 This is another top view schematic diagram of the first preset arrangement of the microspheres described in the specific embodiment;

[0045] Figure 7 This is a schematic diagram of the transparent electrode fabrication method steps described in the second exemplary embodiment;

[0046] Figure 8The silver film transmittance and the ultrathin metal electrode light transmittance of the present application are compared in the following specific embodiments;

[0047] Figure 9 The infrared transmittance of the wavelength of 1350nm-2500nm is compared in the following specific embodiments;

[0048] Figure 10 The coloring response time of the electrochromic device using the transparent electrode prepared by the method shown in the present application is compared with the coloring response time of the electrochromic device using the ITO electrode in the following specific embodiments.

[0049] The reference signs in the drawings include: 1, microspheres; 2, substrate. Specific embodiments

[0050] Hereinafter, embodiments of the present application will be described with reference to the accompanying drawings. In the following description, the same modules are denoted by the same reference signs. In the case of the same reference signs, their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated.

[0051] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not constitute a limitation on the present application.

[0052] Please refer to Figures 1 to 6 In the first aspect, the present application provides a transparent electrode preparation method, comprising:

[0053] S11, performing ultraviolet cleaning treatment on the substrate to improve the hydrophilicity of the substrate surface;

[0054] S12, performing self-assembly treatment on the substrate to make the microspheres distributed on the substrate surface in a first preset manner, and the diameter of the microspheres is 20 nanometers;

[0055] S13, covering the electrode material on the substrate, and the thickness of the electrode material is 2-15 nanometers;

[0056] S14, removing the microspheres on the substrate to obtain a transparent electrode.

[0057] In the embodiment, the ultraviolet cleaning treatment refers to a light cleaning technology using ultraviolet light. The light cleaning technology uses photosensitive oxidation of organic compounds to remove organic substances adhering to the surface of a material. The surface of the material after light cleaning can reach "atomic cleanliness". Specifically, a UV (ultraviolet) light source emits light waves with wavelengths of 185 nm and 254 nm, which have high energy. When these photons act on the surface of the object to be cleaned, most hydrocarbons have strong absorption capacity for ultraviolet light with a wavelength of 185 nm, and decompose into ions, free atoms, excited molecules and neutrons after absorbing the energy of ultraviolet light with a wavelength of 185 nm. This is called photosensitivity. Oxygen molecules in the air also produce ozone and atomic oxygen after absorbing ultraviolet light with a wavelength of 185 nm. Ozone also has strong absorption for ultraviolet light with a wavelength of 254 nm, and decomposes into atomic oxygen and oxygen. Among them, atomic oxygen is extremely active, and under its action, carbon and carbon hydrocarbon decomposition products on the surface of the object can be combined into volatile gases: carbon dioxide and water vapor, etc. escape the surface, thereby completely removing carbon and organic pollutants adhering to the surface of the object.

[0058] When the substrate 2 is cleaned, the wettability of the substrate 2 is increased. The substrate can be transported in a roller mode, and the upper device generates ultraviolet irradiation by a low-pressure mercury lamp. The more ultraviolet energy accumulated by the substrate, the smaller the water contact on its surface, and the two are inversely proportional, thereby achieving the effect of improving the hydrophilicity of the surface of the substrate 2.

[0059] Self-assembly processing is performed on the substrate 2. Self-assembly refers to a technology in which basic structural units (molecules, nanomaterials, micromaterials or larger materials) spontaneously form ordered structures. In the process of self-assembly, the basic structural units spontaneously organize or aggregate into a stable structure with a certain regular geometric appearance based on non-covalent bond interactions. In the embodiment, the first preset distribution mode can refer to the distribution mode shown in Figure 2 、 Figure 3 and Figure 6 , Figure 2 the distribution mode shown in which the microspheres 1 are staggered between multiple rows, Figure 6 the distribution mode shown in which the microspheres 1 are arrayed between multiple rows. Both distribution modes can uniformly distribute the microspheres 1 on the surface of the substrate 2, so that the metal electrodes can be uniformly distributed on the substrate 2 subsequently.

[0060] The electrode material is covered on the substrate 2. The covering mode can be deposition processing or electroplating processing. The specific processing mode is selected according to the substrate 2 and the microspheres 1 and the electrode material. In the embodiment, the thickness of the electrode material is preferably 2-15 nanometers. On the premise of ensuring high conductivity, the redundant accumulation of metal materials is reduced, the weight of the transparent electrode is reduced, and the light transmittance is improved.

[0061] The microspheres 1 on the substrate 2 are removed. The specific removal method is selected according to the material of the microspheres 1. For example, when the microspheres 1 are made of polystyrene, they can be removed by heating; when the microspheres 1 are made of silicon dioxide, they can be washed away by hydrofluoric acid solution.

[0062] Please refer to Figure 4 as well as Figure 5 If the substrate 2 after removing the microspheres 1 has metal electrodes remaining, then the part of the substrate 2 that is in contact with the microspheres 1 is not covered by electrodes, thereby improving the light transmittance of the transparent electrode.

[0063] By setting microspheres 1 with a diameter of 20 nanometers on a substrate 2 and performing self-assembly processing on the microspheres 1, the microspheres 1 are uniformly distributed on the substrate 2. When electrode material is covered on the substrate 2 with microspheres 1, no electrode material is deposited in the part of the substrate 2 that is in contact with the microspheres 1, thereby obtaining higher light transmittance. At the same time, the thickness of the covered electrode material is 2-15 nanometers, which reduces the film thickness while achieving high conductivity, saving metal materials and making it easier to apply transparent electrodes to small devices with low weight requirements. The electrochromic device made by the transparent electrode prepared using the technical solution shown in this application has a significant improvement in color response time compared to the electrochromic device prepared by ITO electrode, further improving the problem of slow response time of large-area electrochromic devices.

[0064] In some embodiments, the following steps are also included:

[0065] After the microspheres are distributed on the substrate surface in a first preset manner, the substrate is subjected to plasma etching to expose part of the substrate surface.

[0066] Plasma etching is a dry etching method that uses plasma. It typically employs high pressure and low radio frequency power. Atoms or molecules on the chip surface come into contact with active atoms in the plasma atmosphere and react, forming gaseous products that leave the crystal plane, thus causing etching. After microspheres 1 are distributed on the surface of substrate 2 in a predetermined manner, if the gaps between microspheres 1 are too small, it will affect the coverage of the electrode material, resulting in uneven coverage of the electrode material on substrate 2 and affecting conductivity. Through plasma etching, the surface of microspheres 1 is etched, widening the gaps between microspheres 1, which does not obstruct the coverage of the electrode material, thus making the electrode material more uniformly distributed on substrate 2 and improving conductivity.

[0067] In some embodiments, the microsphere 1 is a polystyrene microsphere 1, the substrate 2 is a glass substrate 2, and the electrode material covering the substrate includes:

[0068] Low-temperature atomic layer deposition is performed on the substrate to deposit electrode material on the substrate and form a metal electrode;

[0069] Removing the microspheres on the substrate includes:

[0070] The substrate is subjected to a heat treatment at 150°C for 15 minutes to remove the microspheres.

[0071] In the present embodiment, atomic layer deposition is a method that can deposit substances in the form of a monolayer of atomic film on the surface of a substrate, specifically a method that forms a deposition film by alternately passing gas phase precursors into a reactor and chemically adsorbing and reacting on a deposition substrate. Atomic layer deposition has similarities with ordinary chemical deposition. However, in the process of atomic layer deposition, the chemical reaction of a new layer of atomic film is directly associated with the previous layer, which makes each reaction deposit only one layer of atoms. The electrode material is deposited on the substrate 2 by using the atomic layer deposition method to achieve the effect of uniform distribution, forming a metal electrode.

[0072] Polystyrene (abbreviated as PS) refers to a polymer synthesized by free radical polymerization of styrene monomers, and its chemical formula is (C8H8) n . It is a colorless and transparent thermoplastic plastic with a glass transition temperature higher than 100°C. Polystyrene has good electrical properties, with volume resistivity and surface resistivity as high as 10 16 ~ 10 18 Ω·cm and 10 15 ~ 10 18 Ω. The dielectric loss tangent is extremely low and is not affected by frequency and changes in environmental temperature and humidity, making it an excellent insulating material. The substrate 2 is a glass substrate 2, which can change the morphology of the polystyrene microspheres 1 by heating. A heat treatment at a temperature of 150°C for 15 minutes can completely gasify the polystyrene microspheres 1, thereby achieving the effect of removing the polystyrene microspheres 1 from the glass substrate 2.

[0073] Reference can be made to Figure 4 and Figure 5 . After the microspheres 1 are removed, the metal electrode is uniformly distributed on the substrate 2, and there is no metal electrode covering the place where the substrate 2 contacts the microspheres 1, thereby obtaining high light transmittance characteristics. The thickness of the metal electrode is between 2-15 nm, which has high conductivity, so that the transparent electrode made by the method shown in the present embodiment has the advantages of high light transmittance and high conductivity.

[0074] In some embodiments, the microspheres 1 are silica microspheres 1, and the substrate 2 is a calcium fluoride substrate 2 or a barium sulfate substrate 2. Covering the electrode material on the substrate includes:

[0075] Subjecting the substrate to low-temperature atomic layer deposition to deposit the electrode material on the substrate to form a metal electrode;

[0076] Or, vacuum evaporation is performed on the substrate to deposit the electrode material on the substrate to form the metal electrode;

[0077] Or, magnetron sputtering is performed on the substrate to deposit the electrode material on the substrate to form the metal electrode;

[0078] Or, vacuum ion plating is performed on the substrate to deposit the electrode material on the substrate to form the metal electrode;

[0079] The microspheres on the substrate are removed, including:

[0080] The substrate is cleaned with a hydrofluoric acid solution to remove the microspheres.

[0081] Silicon dioxide is an inorganic compound with a chemical formula of SiO2. Silicon atoms and oxygen atoms are arranged in long-range order to form crystalline silicon dioxide, and arranged in short-range order or long-range disorder to form amorphous silicon dioxide. The microspheres 1 made of silicon dioxide are chemically stable and will not react with the electrode, and are also a good substitute for polystyrene microspheres 1. In this embodiment, based on the chemical properties of silicon dioxide, the method for removing the microspheres 1 is changed to cleaning the substrate 2 with a hydrofluoric acid solution. Hydrofluoric acid reacts with silicon dioxide to generate gaseous silicon tetrafluoride. Under this premise, using a glass substrate 2 will cause the hydrofluoric acid to chemically react with the glass substrate 2. Therefore, the material of the substrate 2 cannot be glass, but should be modified to a calcium fluoride substrate 2 or a barium sulfate substrate 2.

[0082] After the material of the substrate 2 is determined, the covering method of the electrode material covering the substrate 2 can be performed by low-temperature atomic layer deposition, vacuum evaporation, magnetron sputtering, and vacuum ion plating. Vacuum evaporation, also known as evaporation, is a process method in which the plating film material (or film material) is evaporated and gasified by a certain heating evaporation method under vacuum conditions, and the particles fly to the substrate surface to condense into a film. Evaporation is an early and widely used gas phase deposition technology, which has the advantages of simple film forming method, high film purity and density, unique film structure and performance, etc. Magnetron sputtering is a kind of physical vapor deposition (PVD). The general sputtering method can be used to prepare metal, semiconductor, insulator and other materials, and has the advantages of simple equipment, easy control, large plating area and strong adhesion. Vacuum ion plating, also known as "vacuum ion deposition", is a surface plating technology in physical vapor deposition. The main feature is that there is a low-pressure plasma zone between the evaporation source and the plated workpiece. When the evaporation molecules (or atoms) pass through, partial ionization occurs, thereby increasing the speed, energy and collision probability of the particles reaching the workpiece, greatly improving the deposition efficiency, the bonding force between the film layer and the workpiece, and the film layer quality.

[0083] Reference can be made to Figure 4 and Figure 5The metal electrode is evenly distributed on the substrate 2 after the microspheres 1 are removed, and no metal electrode covers the place where the substrate 2 contacts the microspheres 1, thereby obtaining the high light transmittance characteristic. The thickness of the metal electrode is between 2-15 nm, and the metal electrode has high conductivity, so that the transparent electrode made by the method shown in the embodiment has the advantages of high light transmittance and high conductivity.

[0084] In some embodiments, the electrode material is any one of silver, gold, zinc, copper, aluminum, and nickel. The electrode material should be selected from materials with good conductivity, small loss in the processing process, and good mechanical processing performance. The thermal performance of the electrode material is closely related to the polarity effect. The higher the melting point and boiling point, the more susceptible the thermal conductivity, specific heat, heat of solution, and heat of vaporization to electric corrosion. The electrode material selected in the embodiment has a significant advantage in polarity effect, and can meet the requirement of high conductivity of the transparent electrode.

[0085] In the second aspect, the present application provides a transparent electrode, which is prepared according to the transparent electrode preparation method of the first aspect.

[0086] Please refer to Figure 7 In the third aspect, the present application provides a transparent electrode preparation method, which comprises:

[0087] S21, performing ultraviolet cleaning treatment on the substrate to improve the hydrophilicity of the surface of the substrate;

[0088] S22, performing self-assembly treatment on the substrate to make the microspheres be distributed on the surface of the substrate in a second preset manner, and the diameter of the microspheres is 40 nm;

[0089] S23, performing heating treatment on the substrate at 150℃ for 5 minutes to make the microspheres decompose into hemispheres and be uniformly arranged on the substrate;

[0090] S24, performing low-temperature atomic layer deposition on the substrate to make the electrode material be deposited on the substrate and form a metal electrode;

[0091] S25, performing heating treatment on the substrate at 150℃ for 10 minutes to remove the microspheres, thereby obtaining a transparent electrode.

[0092] In the embodiment, the ultraviolet cleaning treatment refers to a light cleaning technology using ultraviolet light. The light cleaning technology uses photosensitive oxidation of organic compounds to remove organic substances adhering to the surface of a material. The surface of the material after light cleaning can reach "atomic cleanliness". Specifically, a UV (ultraviolet) light source emits light waves with wavelengths of 185 nm and 254 nm, which have high energy. When these photons act on the surface of the object to be cleaned, most hydrocarbons have strong absorption capacity for ultraviolet light with a wavelength of 185 nm, and decompose into ions, free atoms, excited molecules and neutrons after absorbing the energy of ultraviolet light with a wavelength of 185 nm. This is called photosensitivity. Oxygen molecules in the air also produce ozone and atomic oxygen after absorbing ultraviolet light with a wavelength of 185 nm. Ozone also has strong absorption for ultraviolet light with a wavelength of 254 nm, and decomposes into atomic oxygen and oxygen. Among them, atomic oxygen is extremely active, and under its action, carbon and carbon hydrocarbon decomposition products on the surface of the object can be combined into volatile gases: carbon dioxide and water vapor, etc. escape the surface, thereby completely removing carbon and organic pollutants adhering to the surface of the object.

[0093] When the substrate 2 is cleaned, the wettability of the substrate 2 is increased. The substrate can be transported in a roller mode, and the upper device generates ultraviolet irradiation by a low-pressure mercury lamp. The more ultraviolet energy accumulated by the substrate, the smaller the water contact on its surface, and the two are inversely proportional, thereby achieving the effect of improving the hydrophilicity of the surface of the substrate 2.

[0094] Self-assembly processing is performed on the substrate 2. Self-assembly refers to a technology in which basic structural units (molecules, nanomaterials, micromaterials or larger materials) spontaneously form ordered structures. In the process of self-assembly, the basic structural units spontaneously organize or aggregate into a stable structure with a certain regular geometric appearance based on non-covalent bond interactions. In the embodiment, the second preset distribution mode can refer to the distribution mode shown in Figure 2 、 Figure 3 and Figure 6 , Figure 2 The distribution mode shown in Figure 6 is that the microspheres 1 are staggered between the rows, Both distribution modes can uniformly distribute the microspheres 1 on the surface of the substrate 2, so that the metal electrodes can be uniformly distributed on the substrate 2.

[0095] The electrode material is covered on the substrate 2. The covering mode can be deposition processing or electroplating processing. The specific processing mode is selected according to the substrate 2 and the microspheres 1 and the electrode material. In the embodiment, the thickness of the electrode material is preferably 2-15 nanometers. On the premise of ensuring high conductivity, the redundant accumulation of metal materials is reduced, the weight of the transparent electrode is reduced, and the light transmittance is improved.

[0096] The microspheres 1 on the substrate 2 are removed, and the removal method is selected according to the material of the microspheres 1. For example, when the microspheres 1 are made of polystyrene, the microspheres 1 can be removed by heating. Please refer to Figure 4 and Figure 5 After the microspheres 1 are removed, the substrate 2 is left with metal electrodes, and the part of the substrate 2 in contact with the microspheres 1 is not covered with electrodes, thereby improving the light transmittance of the transparent electrode.

[0097] In this embodiment, the microspheres 1 are made of a material with a heat melting property, which can be gasified at a temperature of 150°C. The substrate 2 is heated at 150°C for 5 minutes to decompose the microspheres 1 into hemispheres and uniformly arrange the hemispheres on the substrate 2, so that the contact area between the substrate 2 and the microspheres 1 is increased, thereby reducing the coverage density of the electrode material on the substrate 2 and obtaining a transparent electrode with higher light transmittance. After the coverage is completed, the substrate 2 is heated at 150°C for 10 minutes to completely remove the microspheres 1 and obtain a complete transparent electrode.

[0098] By arranging the microspheres 1 with a diameter of 40 nanometers on the substrate 2 and performing self-assembly processing on the microspheres 1, the microspheres 1 are uniformly distributed on the substrate 2, and the electrode material is covered on the substrate 2 provided with the microspheres 1, so that the part of the substrate 2 in contact with the microspheres 1 is not deposited with the electrode material, thereby obtaining higher light transmittance. At the same time, the thickness of the covered electrode material is 2-15 nanometers, which reduces the film thickness while realizing high conductivity, saves metal material, and facilitates the application of the transparent electrode in small devices with low weight requirements. The electrochromic device prepared by using the technical solution shown in the present application has a great improvement in the coloring response time compared with the electrochromic device prepared by using the ITO electrode, and further improves the problem of slow response time of large-area electrochromic devices.

[0099] In some embodiments, the method further comprises the following steps:

[0100] After the microspheres are distributed on the surface of the substrate in the second preset manner, the substrate is subjected to plasma etching to expose part of the surface of the substrate.

[0101] Plasma etching is a dry etching method using plasma. Generally, a higher pressure and a smaller RF power are used, atoms or molecules on the surface of the chip are in contact with active atoms in the plasma atmosphere and react to form gaseous products and leave the crystal surface to cause etching. After the microspheres 1 are distributed on the surface of the substrate 2 in the first preset mode, the gap between the microspheres 1 is too small to affect the covering effect of the electrode material, so that the electrode material is not uniformly distributed on the substrate 2, affecting the conductivity. Through plasma etching, the surface of the microspheres 1 is etched, the gap between the microspheres 1 is enlarged, and the covering of the electrode material is not blocked, so that the electrode material is more uniformly distributed on the substrate 2, and the conductivity is improved.

[0102] In some embodiments, the microspheres 1 are polystyrene microspheres 1. In this embodiment, the microspheres 1 can be polystyrene microspheres 1, polystyrene (PS for short) is a polymer synthesized by free radical polymerization of styrene monomers, and the chemical formula is (C8H8)n. It is a colorless and transparent thermoplastic plastic with a glass transition temperature higher than 100℃. Polystyrene has good electrical properties, with volume resistivity and surface resistivity as high as 1016~1018Ω·cm and 1015~1018Ω, respectively. The dielectric loss tangent is extremely low and is not affected by frequency and environmental temperature and humidity changes, making it an excellent insulating material. The substrate 2 is a glass substrate 2, which can change the morphology of the polystyrene microspheres 1 by heating. Heating treatment at a temperature of 150℃ for 5 minutes can make the polystyrene microspheres 1 become hemispherical, and heating treatment at a temperature of 150℃ for 10 minutes can completely gasify the polystyrene microspheres 1, thereby achieving the effect of removing the polystyrene microspheres 1 from the glass substrate 2. By utilizing the chemical properties of polystyrene, the transparent electrode shown in the present application is more convenient to manufacture, improving the manufacturing efficiency.

[0103] In a fourth aspect, the present application also provides a transparent electrode prepared by the transparent electrode preparation method according to the third aspect.

[0104] Please refer to Figures 8 to 10 It can be seen that the transparent electrode prepared by the method of the first aspect and the method of the third aspect has obvious advantages compared with the ITO electrode, which can be referred to Figures 8 to 10 for specific analysis: the light transmittance of the ultra-thin metal electrode of the present application is much higher than that of the metal silver electrode, greatly improving the light transmittance of the metal electrode. The transmittance of ITO in the infrared band is only 20%, which is not much different from Figure 8 the ultra-thin metal electrode, but the infrared transmittance of the electrode of the present application is as high as 80%. At the same time, the sheet resistance is 17.76Ω / □. As Figure 9As shown, the transmittance of the electrode of the present application is significantly improved compared with the ITO electrode in the near-infrared band of 1350 nm-2500 nm. Figure 10 As shown, the electrode device of the present application is significantly faster than the ITO electrode device in terms of coloring speed and response time, and due to the surface plasmon phenomenon occurring within 30 s, the coloring rate is faster, and a blue state is also generated, increasing the color change mode.

[0105] The technical scheme described above, by setting the microspheres 1 with a diameter of 20 nanometers on the substrate 2 and performing self-assembly treatment on the microspheres 1, makes the microspheres 1 uniformly distributed on the substrate 2, and covers the electrode material on the substrate 2 provided with the microspheres 1, so that the part of the substrate 2 in contact with the microspheres 1 is not deposited with the electrode material, thereby obtaining higher light transmittance; at the same time, the thickness of the covered electrode material is 2-15 nanometers, which reduces the film thickness while realizing high conductivity, saves metal materials, and facilitates the application of transparent electrodes in small devices with low weight requirements; the electrochromic device made of the transparent electrode prepared by the technical scheme described in the present application has a great improvement in the coloring response time compared with the electrochromic device prepared by the ITO electrode, further improving the problem of slow response time of large-area electrochromic devices.

[0106] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, different embodiments or examples described in the present specification and the features of different embodiments or examples can be combined and modified by those skilled in the art without contradiction.

[0107] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

[0108] The specific embodiments of the present application described above do not constitute a limitation on the scope of protection of the present application. Any various other corresponding changes and modifications made according to the technical concept of the present application should be included in the scope of protection of the claims of the present application.

Claims

1. A method for producing a transparent electrode, characterized by, The method comprises the following steps: performing ultraviolet cleaning treatment on the substrate to improve the hydrophilicity of the surface of the substrate; performing self-assembly treatment on the substrate to make the microspheres be distributed on the surface of the substrate in a first preset mode, the diameter of the microspheres being 20 nanometers; after the microspheres are distributed on the surface of the substrate in the first preset mode, performing plasma etching on the substrate to expose part of the surface of the substrate; covering electrode material on the substrate, the thickness of the electrode material being 2-15 nanometers; performing heating treatment on the substrate at 150°C for 15 minutes to remove the microspheres on the substrate, so as to obtain a transparent electrode.

2. The method of claim 1, wherein the transparent electrode is prepared by a method comprising: The microspheres are polystyrene microspheres, the substrate is a glass substrate, and covering electrode material on the substrate comprises the following steps: performing low-temperature atomic layer deposition on the substrate to deposit the electrode material on the substrate to form a metal electrode.

3. The method for preparing a transparent electrode according to claim 1, characterized in that, The microspheres are silica microspheres, the substrate is a calcium fluoride substrate or a barium sulfate substrate, and covering electrode material on the substrate comprises the following steps: performing low-temperature atomic layer deposition on the substrate to deposit the electrode material on the substrate to form a metal electrode; or performing vacuum evaporation on the substrate to deposit the electrode material on the substrate to form a metal electrode; or performing magnetron sputtering on the substrate to deposit the electrode material on the substrate to form a metal electrode; or performing vacuum ion plating on the substrate to deposit the electrode material on the substrate to form a metal electrode; The step of removing the microspheres on the substrate comprises the following step: performing hydrofluoric acid solution cleaning on the substrate to remove the microspheres.

4. The method of producing a transparent electrode according to any one of claims 1 to 3, wherein The electrode material is any one of silver, gold, zinc, copper, aluminum and nickel.

5. A transparent electrode, characterized by, The transparent electrode is prepared by the transparent electrode preparation method according to any one of claims 1-4.

6. A method for producing a transparent electrode, characterized by, The method comprises the following steps: performing ultraviolet cleaning treatment on the substrate to improve the hydrophilicity of the surface of the substrate; performing self-assembly treatment on the substrate to make the microspheres be distributed on the surface of the substrate in a second preset mode, the diameter of the microspheres being 40 nanometers; after the microspheres are distributed on the surface of the substrate in the second preset mode, performing plasma etching on the substrate to expose part of the surface of the substrate; performing heating treatment on the substrate at 150°C for 5 minutes to make the microspheres decompose into hemispheres and be uniformly arranged on the substrate; performing low-temperature atomic layer deposition on the substrate to deposit the electrode material on the substrate to form a metal electrode; performing heating treatment on the substrate at 150°C for 10 minutes to remove the microspheres, so as to obtain a transparent electrode.

7. The method of claim 6, wherein the transparent electrode is prepared by sputtering a metal layer on the substrate. The microspheres are polystyrene microspheres.

8. A transparent electrode, characterized by, The transparent electrode is prepared by the transparent electrode preparation method according to any one of claims 6-7. The transparent electrode is prepared by the transparent electrode preparation method according to any one of claims 6-7.

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