Manufacturing method of large-area blade coating flexible transparent conductive film

Abstract

The invention provides a method for manufacturing a large-area blade-coating flexible transparent conductive film, and particularly relates to a method for preparing a low-cost flexible transparent conductive film by adopting a large-area blade-coating technology. And then coating a layer of high-conductivity material, and then carrying out hot-pressing transfer printing to obtain the high-performance flexible transparent conductive thin film. The flexible transparent conductive thin film prepared by the method inherits a smooth surface of an original substrate after transfer printing, shows relatively high photoelectric property and mechanical flexibility, and has a wide application prospect in the photoelectric field (such as a light emitting diode, a panel display technology, a solar cell, a flexible sensor and the like).

Description

Technical Field

[0001] The present invention relates to the technical field of optoelectronic devices, and in particular to a method for manufacturing a large-area scraping-coated flexible transparent conductive film. Background Art

[0002] With the rapid development of the new generation of information technology, various optoelectronic devices (such as light-emitting diodes, flat-panel display technology, solar cells, and flexible sensors) require high-performance transparent conductive films as electrodes to achieve excellent device performance. The development of flexible portable and wearable electronic devices also further requires optoelectronic devices to have certain bendability. This requires transparent conductive films to have excellent optoelectronic properties (such as conductivity and transmittance), high surface smoothness, excellent bending flexibility, and low production cost. Scraping technology mainly uses a scraper to evenly apply ink to the substrate surface. It has the advantages of being environmentally friendly, low-cost, and able to cover large areas. It has obvious advantages in the preparation of flexible transparent conductive films. Compared with traditional evaporation and magnetron sputtering technologies, scraping technology can achieve large-scale and low-cost preparation of high-performance flexible transparent conductive films, which is of great significance for the practical application of various flexible optoelectronic devices. Summary of the Invention

[0003] In order to solve the above-mentioned technical problems, the present invention provides a method for producing a large-area scraping flexible transparent conductive film to address the shortcomings of the existing technology in terms of environmental protection, preparation cost, optoelectronic performance, large-area preparation, etc. The flexible transparent conductive film produced by the present invention exhibits significant advantages in terms of conductivity, transmittance, surface uniformity, smoothness, mechanical flexibility, etc., and can simultaneously meet the performance requirements of optoelectronic devices such as light-emitting diodes, flat panel display technology, solar cells, and flexible sensors for flexible transparent conductive films.

[0004] To achieve the above objectives, the present invention provides a method for producing a large-area scraping flexible transparent conductive film, which is obtained by pre-coating a layer of composite conductive material on a substrate, then coating a layer of highly conductive material, and then performing hot pressing transfer. The specific steps of producing the flexible transparent conductive film are as follows: S1. A layer of composite conductive material is scraped onto substrate A and annealed; S2. Further coating a layer of highly conductive material on the upper layer of the composite conductive material in step S1 and annealing; S3. Coating a liquid substrate material B on the top layer of the highly conductive material in step S2, embedding the composite conductive material from step S1 and the highly conductive material from step S2 into the substrate material B under heating and pressurizing conditions, and curing the substrate material B to form a solid film by heating; S4. Peel off the B substrate together with the composite conductive material of step S1 and the highly conductive material of step S2 from the A substrate to obtain a flexible transparent conductive film.

[0005] As an improvement of the present invention, the substrate A is any one of glass, silicon wafer, steel sheet, polyethylene terephthalate (PET), polyimide (PI), polyethylene (PE), polycarbonate (PC), and polyvinyl alcohol (PVA).

[0006] As an improvement of the present invention, the B substrate is any one of polydimethylsiloxane (PDMS), highly transparent granular elastomer material (SBS), transparent polyurethane elastomer, thermoplastic elastomer (TPE), thermoplastic polyurethane elastomer (TPU), and hydrogenated styrene-butadiene block copolymer (SEBS).

[0007] As an improvement of the present invention, the composite conductive material in step S1 is silver nanowires and poly (3,4-ethylenedioxythiophene) / polystyrene sulfonate, the volume ratio of the silver nanowires to poly (3,4-ethylenedioxythiophene) / polystyrene sulfonate is 0.3:1, and the coating thickness of the composite conductive material is 100 to 200 nm.

[0008] As an improvement to the present invention, the highly conductive material in step S2 is any one of silver nanowires, copper nanowires, silver nanoparticles, copper nanoparticles, poly (3,4-ethylenedioxythiophene) / polystyrene sulfonate), carbon nanotubes, and graphene. The highly conductive material is applied by scraping to a thickness of 100 to 200 nm.

[0009] As an improvement of the present invention, the annealing treatment temperature in step S1 and step S2 is 60-100°C.

[0010] As an improvement of the present invention, the heating temperature in step S3 is 70° C. and the pressure is 15 kPa.

[0011] As an improvement of the present invention, the curing temperature in step S3 is 80-120°C.

[0012] The beneficial effects of the present invention are: This method pre-coats a layer of composite conductive material on a substrate, which then inherits the substrate's smooth surface through inter-filling. A further layer of highly conductive material is then applied to provide the required conductivity for the transparent conductive film. Both layers are then embedded into another substrate using a hot-press transfer technique. The resulting flexible transparent conductive film exhibits high optoelectronic performance, surface smoothness, and excellent mechanical flexibility, making it suitable for use as a transparent electrode in flexible optoelectronic devices.

[0013] In addition, the use of scraping technology to prepare flexible transparent conductive films can significantly reduce preparation costs, achieve large-scale manufacturing, and have green and environmentally friendly advantages, meeting the industrialization needs of various optoelectronic devices such as light-emitting diodes, flat panel display technology, solar cells, and flexible sensors for high-performance flexible transparent conductive films. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of the preparation process of the flexible transparent conductive film of the present invention; Figure 2 This is a photo of the flexible transparent conductive film obtained by the preparation method described in Example 1; Figure 3 This is a photograph of the flexible transparent conductive film obtained by the preparation method described in Example 1 under a scanning electron microscope; Figure 4 This is a transmittance curve of the flexible transparent conductive film obtained by the preparation method described in Example 1; Figure 5 The square resistance distribution of the flexible transparent conductive film obtained by the preparation method described in Example 1 (20 samples); Figure 6 This is a bending performance test curve of the flexible transparent conductive film obtained by the preparation method described in Example 1; Figure 7 This is a photo of the flexible transparent conductive film (placed on a glass rod) obtained by the preparation method described in Example 2; Figure 8 This is a photo of the flexible transparent conductive film (placed on a leaf) obtained by the preparation method described in Example 9.

[0015] List of Figure Symbols: 1. A substrate; 2. Composite conductive material; 3. High conductive material; 4. B substrate. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only intended to illustrate the present invention and are not intended to limit the scope of the present invention. The materials, reagents, instruments, etc. used in the examples are commercially available unless otherwise specified. It should be understood that the embodiments described herein are only some embodiments of the present invention and are not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments in which the experimental steps and conditions of the present invention are modified or replaced fall within the scope of protection of the present invention.

[0017] Example 1 S1. A composite conductive film was coated on a glass substrate using a doctor blade technique and annealed at 60°C. The composite conductive film had a thickness of 100 nm and was composed of silver nanowires and poly (3,4-ethylenedioxythiophene) / polystyrene sulfonate (PEDOT:PSS PH1000). The volume ratio of silver nanowires to poly (3,4-ethylenedioxythiophene) / polystyrene sulfonate was 0.3:1. S2. Coating a layer of silver nanowire film on the composite conductive film of step S1 by using a doctor blade technique, and annealing the layer at 60° C. The thickness of the silver nanowire film is 100 nm. S3. A liquid polydimethylsiloxane (PDMS) solution is uniformly coated on the silver nanowire film of step S2. The composite conductive film of step S1 and the silver nanowire film of step S2 are completely embedded in the PDMS substrate under heating (70°C) and pressure (15 kPa). The two conductive films are then embedded in the PDMS substrate by hot pressing (80°C, using a high-thermal-conductivity aluminum plate to apply pressure). S4. Peel off the PDMS substrate together with the two layers of conductive material from the glass substrate as a whole to obtain a flexible transparent conductive film.

[0018] The flexible transparent conductive film prepared by this method has high photoelectric performance (transmittance ~91.3%, square resistance ~11.2 Ω sq −1 ), low surface roughness (~2.77 nm), excellent mechanical flexibility, and the film preparation has high repeatability and good surface uniformity. Figure 2 As shown in the scanning electron microscope photo of the flexible transparent conductive film Figure 3 As shown in the figure, the transmittance curve of the flexible transparent conductive film is as follows Figure 4 As shown in Figure 2, the square resistance distribution of the flexible transparent conductive film (20 samples) is as follows: Figure 5 As shown, the bending performance test curve of the flexible transparent conductive film is as follows Figure 6 shown.

[0019] Example 2 S1. A composite conductive film was coated on a glass substrate using a doctor blade technique and annealed at 80°C. The composite conductive film had a thickness of 100 nm and was composed of silver nanowires and poly (3,4-ethylenedioxythiophene) / polystyrene sulfonate (PEDOT:PSS) PH1000. The volume ratio of the silver nanowires to the poly (3,4-ethylenedioxythiophene) / polystyrene sulfonate was 0.3:1. S2. Coating a layer of silver nanowire film on the composite conductive film of step S1 by using a doctor blade technique, and annealing the layer at 60° C. The thickness of the silver nanowire film is 100 nm. S3. A liquid polydimethylsiloxane (PDMS) solution is uniformly coated on the silver nanowire film of step S2. The composite conductive film of step S1 and the silver nanowire film of step S2 are completely embedded in the PDMS substrate under heating (70°C) and pressure (15 kPa). The two conductive films are then embedded in the PDMS substrate by hot pressing (80°C, using a high-thermal-conductivity aluminum plate to apply pressure). S4. Peel off the PDMS substrate together with the two layers of conductive material from the glass substrate as a whole to obtain a flexible transparent conductive film.

[0020] The flexible transparent conductive film prepared by this method has high photoelectric performance (transmittance ~90%, square resistance ~12.2 Ω sq −1 ), low surface roughness (~3.5 nm), excellent mechanical flexibility, and the film preparation has high repeatability and good surface uniformity. Figure 7 shown.

[0021] Example 3 S1. A composite conductive film was coated on a glass substrate using a doctor blade technique and annealed at 100°C. The composite conductive film had a thickness of 100 nm and was composed of silver nanowires and poly (3,4-ethylenedioxythiophene) / polystyrene sulfonate (PEDOT:PSS PH1000). The volume ratio of silver nanowires to poly (3,4-ethylenedioxythiophene) / polystyrene sulfonate was 0.3:1. S2. Coating a layer of silver nanowire film on the composite conductive film of step S1 by using a doctor blade technique, and annealing the layer at 60° C. The thickness of the silver nanowire film is 100 nm. S3. A liquid polydimethylsiloxane (PDMS) solution is uniformly coated on the silver nanowire film of step S2. The composite conductive film of step S1 and the silver nanowire film of step S2 are completely embedded in the PDMS substrate under heating (70°C) and pressure (15 kPa). The two conductive films are then embedded in the PDMS substrate by hot pressing (80°C, using a high-thermal-conductivity aluminum plate to apply pressure). S4. Peel off the PDMS substrate together with the two layers of conductive material from the glass substrate as a whole to obtain a flexible transparent conductive film.

[0022] The flexible transparent conductive film prepared by this method has high photoelectric performance (transmittance ~89%, square resistance ~13.1 Ω sq−1 ), low surface roughness (~4.5 nm), excellent mechanical flexibility, and the film preparation has high repeatability and good surface uniformity. Figure 8 shown.

[0023] Of particular note is the fact that the flexible transparent conductive film preparation method provided in this application offers advantages over traditional small-area coating techniques such as spin coating or screen printing in large-scale fabrication (i.e., doctor blade coating is compatible with roll-to-roll large-area fabrication). Furthermore, because this application combines doctor blade coating with hot-press transfer printing for the first time, it enables flexible transparent electrodes to be fabricated over large areas while also exhibiting superior optoelectronic performance (the flexible transparent electrodes fabricated in this application exhibit no significant performance degradation at meter-scale scales), thus overcoming the technical barrier that hinders the large-scale fabrication of flexible transparent conductive films while maintaining high optoelectronic performance.

[0024] It should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. For ordinary technicians in this technical field, without departing from the principles of the present invention, several improvements and modifications can be made on the basis of the above embodiments, and these improvements and modifications all fall within the scope of protection of the claims of the present invention.

Claims

1. A method for producing a large-area scraping flexible transparent conductive film, characterized in that: The specific steps of the production method are: S1. A layer of composite conductive material is scraped onto substrate A and annealed; S2. Further coating a layer of highly conductive material on the upper layer of the composite conductive material in step S1 and annealing; S3. Coating a liquid substrate material B on the top layer of the highly conductive material in step S2, embedding the composite conductive material from step S1 and the highly conductive material from step S2 into the substrate material B under heating and pressurizing conditions, and curing the substrate material B to form a solid film by heating; S4. Peel off the B substrate together with the composite conductive material of step S1 and the highly conductive material of step S2 from the A substrate to obtain a flexible transparent conductive film.

2. The method for producing a large-area scraping flexible transparent conductive film according to claim 1, characterized in that: The substrate A is any one of glass, silicon wafer, steel sheet, polyethylene terephthalate, polyimide, polyethylene, polycarbonate, and polyvinyl alcohol.

3. The method for manufacturing a large-area scraping flexible transparent conductive film according to claim 1, characterized in that: The B substrate is any one of polydimethylsiloxane, highly transparent granular elastomer material, transparent polyurethane elastomer, thermoplastic elastomer, thermoplastic polyurethane elastomer, and hydrogenated styrene-butadiene block copolymer.

4. The method for manufacturing a large-area scraping flexible transparent conductive film according to claim 1, characterized in that: The composite conductive material in step S1 is silver nanowires and poly (3,4-ethylenedioxythiophene) / polystyrene sulfonate, the volume ratio of the silver nanowires to poly (3,4-ethylenedioxythiophene) / polystyrene sulfonate is 0.3:1, and the coating thickness of the composite conductive material is 100-200 nm.

5. The method for manufacturing a large-area scraping flexible transparent conductive film according to claim 1, characterized in that: In step S2, the highly conductive material is any one of silver nanowires, copper nanowires, silver nanoparticles, copper nanoparticles, poly (3,4-ethylenedioxythiophene) / polystyrene sulfonate, carbon nanotubes, and graphene, and the coating thickness of the highly conductive material is 100 to 200 nm.

6. The method for manufacturing a large-area scraping flexible transparent conductive film according to claim 1, characterized in that: The annealing temperature in step S1 and step S2 is 60-100°C.

7. The method for manufacturing a large-area scraping flexible transparent conductive film according to claim 1, characterized in that: In step S3, the heating temperature is 70° C. and the pressure is 15 kPa.

8. The method for manufacturing a large-area scraping flexible transparent conductive film according to claim 1, characterized in that: The curing temperature in step S3 is 80-120°C.

Images