Low-roughness AgNW electrode based on electronic jet printing technology and application of low-roughness AgNW electrode in intrinsic flexible polymer light-emitting diode
The preparation of AgNW film electrodes on the elastomer substrate through electrospray printing process solves the problem of insufficient performance of flexible display screens during multi-curvature deformation or stretching, and achieves low roughness, high conductivity and high tensile resistance AgNW electrodes, which improves the display performance and stability of IFPLED.
Patent Information
- Application Number
- CN202311581374.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-24
- Publication Date
- 2025-05-27
AI Technical Summary
The existing flexible display screens are difficult to meet the requirements of high elastic deformation, low bending radius and high tensile strain during multi-curvature deformation or stretching, and the AgNW electrode has a large roughness and high resistance, which affects the display performance.
The AgNW film electrode was directly patterned on the elastomer substrate by electrospraying technology. AgNW electrodes with low roughness, high tensile properties, high conductivity and low resistance were prepared by optimizing process conditions such as voltage, needle model, ink extrusion rate and substrate movement rate.
AgNW electrodes with medium and low roughness and low resistance in high-flex display devices have been realized, improving the brightness, stability and tensile resistance of IFPLED, and are suitable for intrinsic flexible drive displays, brain-computer interfaces and soft robots.
Smart Images
Figure CN120051175A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a low-roughness AgNW electrode based on an electrospray printing process and its application in an intrinsically flexible polymer light-emitting diode, belonging to the technical field of intrinsically flexible electronic devices. Background Art
[0002] With the development of flexible display technology, display forms have increasingly diversified into people's lives. The emergence and application of edge-bending, bendable, foldable, and rollable displays in electronic products have successively occurred. However, when the display screen undergoes multi-curvature deformation or direct stretching, large stress and strain will be generated. Existing flexible display screens are difficult to meet the requirements due to their size and shape limitations. Therefore, stretchable displays with more degrees of freedom of deformation have received increasing attention as a new future display form, and research on functional materials and technologies for stretchable displays has become more active. Currently, feasible solutions for stretchable displays include structural stretchable displays and intrinsically flexible displays. Structural stretching involves designing the display device as an island-bridge structure, placing brittle film layers such as semiconductor layers, dielectric layers, and electrodes in the display islands, and connecting the display islands through conductor signal lines via connecting bridges. During stretching, the bridges deform while the islands do not deform, thus achieving the stretching of the display screen. Intrinsic flexibility stems from bond rotation, conformational interconversion, molecular chain extension / slip, and the formation of dynamic bonds. Different from stretchable displays, intrinsically flexible displays should simultaneously meet three key requirements (Natl Sci Rev, 2022, Vol. 9, nwac090): high elastic deformation, a bending radius of less than 0.5 mm, and a tensile strain of more than 25%. In addition, they should also have the ability to adapt to moduli across scales (1 KPa - 10 GPa) so that the display can be attached, folded, or curled, thereby truly realizing human-computer interaction everywhere.
[0003] The intrinsic flexible electrode is one of the main bottleneck problems in realizing intrinsic flexible display devices. An excellent electrode functional layer not only requires good stretchability, conductivity, solution processability, but also has relatively high requirements for the roughness of the film to avoid breakdown and conduction problems during the stretching process. AgNW is a commonly used stretchable electrode material with excellent conductivity (about 9 Ω / sq), transmittance (about 89%), and mechanical flexibility. It can produce transparent conductive films through a coating process, and the production cost is much lower than that of indium tin oxide (ITO), which is regarded as the best substitute for ITO materials (Nanoscale 2012, 4, 6408 - 6414). Currently, the coating process usually uses a spin coating or spraying process to obtain a free-penetrating network of AgNW. However, the prepared conductive film inevitably has a large film roughness and increased resistance due to the large contact resistance between nanowires. Therefore, how to combine processes to prepare AgNW electrodes with high stretchability, high conductivity, low roughness, and low resistance, and further apply them to IFPLED is of great research significance for realizing intrinsic flexible display. Summary of the Invention
[0004] The object of the present invention is to provide a method for directly patterning a highly stretchable, highly conductive, low-roughness, and low-resistance AgNW electrode on an elastomeric substrate based on an electrospray printing process and applying it to an IFPLED device.
[0005] The present invention first provides a method for preparing an AgNW thin film electrode, comprising the following steps:
[0006] Pattern printing of AgNW ink on a substrate by electrospray printing to obtain it;
[0007] The dispersion liquid of the AgNW ink can be water, ethanol, or isopropanol;
[0008] The concentration of the AgNW ink is 5 - 10 mg / mL;
[0009] The length of the AgNW is 20 - 50 μm, and the diameter is 20 - 50 nm.
[0010] The conditions of the electrospray printing are as follows:
[0011] The voltage is 1 - 10 kV, the spray needle model is one of 21G, 23G, 24G, 25G, 26G, 27G, 30G, 32G, and 34G, the distance between the spray needle and the substrate is 0.1 - 0.5 mm, the extrusion rate of the ink is 2 - 100 μL / min, the substrate moving rate is 1 - 300 mm / s, and the printing cycle is 1 - 10 times.
[0012] The thickness of the AgNW thin film electrode prepared by the method of the present invention is 30 - 100 nm.
[0013] The AgNW thin film electrode provided by the present invention can be used in highly flexible display devices, stretchable display devices, and intrinsically flexible display devices.
[0014] Based on the AgNW thin film electrode, the present invention further provides an intrinsically flexible polymer light-emitting diode, which includes a substrate, a sacrificial layer, an elastomeric substrate, an intrinsically flexible anodic electrode, an intrinsically flexible hole transport layer, an intrinsically flexible light-emitting layer, an intrinsically flexible electron transport layer, and an intrinsically flexible cathodic electrode arranged in sequence;
[0015] Both the intrinsically flexible anodic electrode and the intrinsically flexible cathodic electrode are the AgNW thin film electrodes of the present invention.
[0016] Among them, the substrate is selected from any one of silicon wafers, glass, ceramics, and quartz;
[0017] The sacrificial layer is selected from at least one of octadecyltrimethoxysilane, octadecyltrichlorosilane, octyltrichlorosilane, and phenyltrichlorosilane, and is prepared by heat treatment under vacuum conditions or immersion treatment in a solution;
[0018] The elastomeric substrate is prepared by solution spin coating from any one of polyurethane elastomers, polydimethylsiloxane, hydrogenated styrene-butadiene block copolymer, and styrene-butadiene rubber, and the concentration can be 150 - 250 mg / mL;
[0019] The surface of the elastomeric substrate needs to be treated by ultraviolet ozonation;
[0020] The thickness of the elastomeric substrate is 0.3 mm - 2 mm.
[0021] Among them, the intrinsically flexible light-emitting layer is prepared by solution spin coating from an intrinsically flexible hybrid polymer blend system;
[0022] The intrinsically flexible hybrid polymer blend system is a blend of an elastomeric polymer and a light-emitting conjugated polymer;
[0023] The light-emitting conjugated polymer is any one of poly[{2,5-bis(3’,7’-dimethyloctyloxy)-1,4-phenyleneethynylene}-co-{3-(4’-(3”,7”-dimethyloctyloxy)phenyl)-1,4-phenyleneethynylene}-co-{3-(3’-(3”,7”-dimethyloctyloxy)phenyl)-1,4-phenyleneethynylene}], poly(9,9-dioctylfluorene-2,7-diyl), and poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenyleneethynylene] (MEH-PPV), and its concentration can be 1 - 15 mg / mL;
[0024] The elastomeric polymer is any one of polyurethane elastomer, polydimethylsiloxane, hydrogenated styrene-butadiene block copolymer, and styrene-butadiene rubber;
[0025] The mass ratio of the luminescent conjugated polymer to the elastomeric polymer is 1:9 to 5:5;
[0026] The thickness of the intrinsic flexible luminescent layer is 30 to 100 nm.
[0027] Among them, the intrinsic flexible hole transport layer is prepared by solution spin coating from a blend of poly(3,4-ethylenedioxythiophene)-polystyrenesulfonic acid and any one of Triton-100, Triton-45, and sorbitol, with a ratio of 1:1 to 1:3;
[0028] The intrinsic flexible electron transport layer is prepared by solution spin coating from a blend of poly(ethoxyethylenimine) (PEIE) and any one of zinc acetate dihydrate, 4,7-diphenyl-1,10-phenanthroline, and poly(9,9-bis(3'-(N,N-dimethyl)-N-ethylaminopropyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)) dibromide, with a ratio of 1:1 to 1:5, and the concentration can be 1 to 10 mg / ml;
[0029] Among them, the solvent of the solution used in the solution spin coating method is toluene, xylene, chlorobenzene, dichlorobenzene, chloroform, dichloromethane, tetrahydrofuran, dimethyl sulfoxide, N,N-dimethylformamide, methanol, ethanol, isopropanol, water, or n-hexane cyclohexane.
[0030] By optimizing the electrospray printing process conditions, the present invention prepares an intrinsic flexible AgNW electrode film with low roughness, high stretchability, high conductivity, high transparency, and large-area integration, and applies it to high-performance IFPLED. Its preparation process is simple and the cost is low, and large-area integration can be achieved. The IFPLED prepared by the present invention has a low turn-on voltage, high brightness, and excellent stability, and has broad application prospects in the fields of intrinsic flexible drive display, brain-computer interface, artificial intelligence, and soft robots. Description of the Drawings
[0031] Figure 1 It is a schematic structural diagram of the IFPLED device provided by the present invention.
[0032] Figure 2 It is an optical microscope image of the intrinsic flexible AgNW thin film electrode prepared in Example 1 (Figure a) and Comparative Example 1 (Figure b) of the present invention.
[0033] Figure 3 It is an AFM image of the intrinsic flexible AgNW thin film electrode prepared in Example 1 (Figure a) and Comparative Example 1 (Figure b) of the present invention.
[0034] Figure 4 SEM images of the intrinsic flexible AgNW thin film electrodes prepared in Example 1 (Figure a) and Comparative Example 1 (Figure b) of the present invention.
[0035] Figure 5 Large-area intrinsic flexible AgNW thin film electrode array prepared in Example 2 of the present invention.
[0036] Figure 6 Variation relationship of the conductivity of the intrinsic flexible AgNW thin film electrode prepared in Example 2 of the present invention with the tensile strain.
[0037] Figure 7 Brightness-current density-voltage curve of the IFPLED prepared in Example 2 of the present invention.
[0038] Figure 8 Relationship curve of the brightness of the IFPLED prepared in Example 2 of the present invention with the stretchability and pictures showing the anti-tensile performance.
[0039] Figure 9 Variation relationship of the resistivity of the intrinsic flexible AgNW thin film electrode prepared in Example 2 of the present invention with the tensile strain.
[0040] Figure 10 Picture of the intrinsic flexible AgNW thin film electrode prepared in Example 3 of the present invention. Detailed implementation manners
[0041] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods.
[0042] Unless otherwise specified, the materials, reagents, etc. used in the following examples can all be obtained from commercial channels.
[0043] In the following examples, the mechanical properties and electrical properties of the IFPLED are measured under a nitrogen atmosphere and at room temperature.
[0044] The IFPLED based on the intrinsic flexible AgNW thin film electrode provided by the present invention has a vertical structure, and its structure is as Figure 1 shown, and successively includes an elastomer substrate, an intrinsic flexible anodic electrode, an intrinsic flexible hole transport layer, an intrinsic flexible light-emitting layer, an intrinsic flexible electron transport layer, and an intrinsic flexible cathodic electrode from bottom to top; wherein, the intrinsic flexible anodic electrode and the intrinsic flexible cathodic electrode are prepared by an electrospray printing process.
[0045] The specifications of the AgNW used in the following examples are as follows: the diameter is 30 nm and the length is 20 μm.
[0046] Example 1: Preparation of Intrinsic Flexible AgNW Thin Film Electrodes Based on Electrospray Printing Process
[0047] 1) Using a silicon wafer as the substrate, successively ultrasonic clean it with dishwashing liquid, deionized water, acetone, and isopropyl alcohol at a power of 50 W and a frequency of 30 kHz for 10 min. After drying with a nitrogen gun, perform ultraviolet ozone treatment on the cleaned silicon wafer for 10 min at a power of 100 Hz to obtain a clean silicon wafer.
[0048] 2) Place the silicon wafer in step 1) on the sample stage of the electrospray printing instrument. Use a 2.5 ml glass syringe to extract AgNW ink (concentration 5 mg / ml, solvent is isopropyl alcohol), set the extrusion rate of the ink to 5 μL / min, the substrate moving rate to 30 mm / s, the printing cycle to 1, the voltage between 5 kV and 7 kV, the needle model to 30G, and the distance between the needle and the substrate to 0.1 mm. Print the AgNW ink at room temperature to obtain a patterned intrinsic flexible AgNW thin film electrode, and the thickness of the thin film electrode is about 50 nm.
[0049] Comparative Example 1: Preparation of Intrinsic Flexible AgNW Thin Film Electrodes Based on Spin Coating Process
[0050] Prepare a cleaned silicon wafer treated with ozone in the same method as step 1) of Example 1. Place the silicon wafer at the center of the rotor of the spin coater. Use a 200 μL pipette to extract 150 μL of AgNW ink (the same as the AgNW ink used in Example 1), and then evenly drop 100 μL of it onto the substrate. Start the spin coater and keep it at a speed of 1000 rpm for 1 min. Finally, remove the silicon wafer and place it on a hot plate at 100 °C for 5 minutes to obtain an intrinsic flexible AgNW thin film electrode based on the spin coating process. The thickness of the thin film electrode is the same as that of Example 1, about 50 nm.
[0051] Figures 2 - 4 are the comparative images of the optical microscope, AFM, and SEM of the electrodes prepared in Example 1 and Comparative Example 1. By comparing the AFM images ( Figure 3 ) it can be seen that the roughness of the spin-coated thin film electrode is 27.4 nm, and the roughness of the thin film electrode by the electrospray printing process is reduced to 5.50 nm. The microscopic morphology of the intrinsic flexible AgNW thin film electrode prepared in Example 1 has no obvious aggregation phenomenon compared with that prepared in Comparative Example 1, indicating that the electrospray printing process makes the AgNW more uniform and even has a certain orientation, so it is more conducive to the preparation of low-roughness AgNW thin film electrodes, thereby improving the performance of IFPLED devices.
[0052] Example 2: Preparation of IFPLED Based on the Intrinsic Flexible AgNW Thin Film Electrode of Example 1
[0053] 1) Using a glass slide as the substrate, successively ultrasonic clean it with dishwashing liquid, deionized water, acetone, and isopropyl alcohol for 10 min at a power of 50 W and a frequency of 30 kHz. After drying it with a nitrogen gun, perform ultraviolet ozone treatment (power of 100 Hz) on the cleaned glass slide for 10 min. Then, place the clean glass slide in a clean glass Petri dish, add n - hexane and octadecyltrimethoxysilane with a volume ratio of 1000:1 using a pipette, and place the Petri dish at room temperature and atmospheric conditions for 5 min. Take out the glass slide, and a glass slide with a self - assembled molecular layer can be obtained.
[0054] 2) Place the glass slide with a self - assembled molecular layer on a hot stage, slowly extract 0.5 ml of the DMF solution of TPU (concentration of 200 mg / mL) with a 1 mL syringe, and evenly drip - coat it on the glass slide with a self - assembled molecular layer (including glass slides of two specifications: 2 cm×2 cm and 5 cm×5 cm). Then, anneal it at 100 °C for 2 hours to obtain an elastomeric substrate with a thickness of 1 mm.
[0055] 3) Perform ultraviolet ozone treatment (power of 100 Hz) on the elastomeric substrate (2 cm×2 cm) prepared in step 2) for 10 min. Then, place the treated elastomeric substrate on the sample stage of an electro - spray printing instrument. Use a 2.5 ml glass syringe to extract AgNW ink (the same as the AgNW ink used in Example 1), set the extrusion rate of the ink to 10 μL / min, the moving rate of the substrate to 50 mm / s, and the printing cycle to 1. Print the AgNW ink at room temperature to obtain a patterned intrinsic flexible AgNW thin - film electrode, and the thickness of the thin - film electrode is about 50 nm. The intrinsic flexible AgNW thin - film electrode prepared on the 2 cm×2 cm elastomeric substrate is used for the preparation of IFPLED devices and the test of the change of conductivity with stretchability ( Figure 6 ), and the 5 cm×5 cm elastomeric substrate is used for the display of large - area arrays ( Figure 5 ).
[0056] 4) Place the elastomeric substrate with the intrinsic flexible AgNW thin film anodic electrode prepared in step 3) at the center of the rotor of the spin coater. Use a 200 μL pipette to aspirate 100 μL of the mixed solution of PEDOT / PSS and Triton X-100 (the solvent is water, and the mass ratio of PEDOT / PSS to Triton X-100 is 1:2.5). Then evenly drop 100 μL of the mixed solution of PEDOT / PSS and Triton X-100 onto the elastomeric substrate with the intrinsic flexible AgNW thin film electrode. Start the spin coater and maintain it at a speed of 2000 rpm for 1 min. Finally, remove the substrate and anneal it on a hot plate at 100 °C for 30 min to obtain an elastomeric substrate with an intrinsic flexible AgNW thin film anodic electrode and an intrinsic flexible hole transport layer thin film. The thickness of the intrinsic flexible hole transport layer thin film is 70 nm.
[0057] 5) Place the elastomeric substrate with the intrinsic flexible AgNW thin film anodic electrode and the intrinsic flexible hole transport layer thin film prepared in step 4) at the center of the rotor of the spin coater. Use a 200 μL pipette to aspirate 100 μL of the tetrahydrofuran solution of poly[{2,5-bis(3’,7’-dimethyloctyloxy)-1,4-phenyleneethynylene}-co-{3-(4’-(3”,7”-dimethyloctyloxy)phenyl)-1,4-phenyleneethynylene}-co-{3-(3’-(3”,7”-dimethyloctyloxy)phenyl)-1,4-phenyleneethynylene}] (SY-PPV) / polyurethane (where the mass ratio of the two polymers is 3:7, and the concentration of SY-PPV in the mixture solution is 10 mg / mL). Then evenly drop 70 μL of it onto the substrate. Start the spin coater and maintain it at a speed of 2000 rpm for 1 min. Finally, remove the silicon wafer and keep it on a hot plate at 80 °C for 20 minutes to obtain an elastomeric substrate with an intrinsic flexible AgNW thin film anodic electrode, an intrinsic flexible hole transport layer thin film, and an intrinsic flexible light-emitting layer thin film. The thickness of the intrinsic flexible light-emitting layer thin film is 70 nm.
[0058] 6) Place the elastomeric substrate with the intrinsic flexible AgNW thin film anodic electrode, the intrinsic flexible hole transport layer thin film, and the intrinsic flexible light-emitting layer thin film prepared in step 5) at the center of the rotor of a spin coater. Use a 200 μL pipette to extract 150 μL of a mixed solution of poly(ethoxyethyleneimine) (PEIE) and poly(9,9-bis(3'-(N,N-dimethyl)-N-ethylaminopropyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene) dibromide (where the mass ratio of the two polymers is 1:1, the concentration of PEIE in the mixture solution is 5 mg / ml, and the solvent is methanol). Then evenly drip 100 μL of it onto the substrate, start the spin coater, and maintain it at a speed of 2000 rpm for 1 min. Finally, remove the silicon wafer and place it on a hot plate at 100 °C for 5 minutes to obtain an elastomeric substrate with an intrinsic flexible AgNW thin film anodic electrode, an intrinsic flexible hole transport layer thin film, an intrinsic flexible light-emitting layer thin film, and an intrinsic flexible electron transport layer thin film. The thickness of the intrinsic flexible electron transport layer thin film is 40 nm.
[0059] 7) Place the elastomeric substrate with the intrinsic flexible AgNW thin film anodic electrode, the intrinsic flexible hole transport layer thin film, the intrinsic flexible light-emitting layer thin film, and the intrinsic flexible electron transport layer thin film prepared in step 6) on the sample stage of an electrospray printing instrument. Referring to the operation method and process conditions in step 3), print AgNW ink on the substrate to obtain a patterned intrinsic flexible AgNW thin film cathodic electrode, and the thickness of the thin film cathodic electrode is about 50 nm.
[0060] The IFPLED based on the intrinsic flexible AgNW thin film electrode can be prepared by the above steps.
[0061] Comparative Example 2
[0062] According to the exactly same preparation method as in Example 2, only change the preparation method of the AgNW electrode in steps 3) and 7) to the spin coating process. The IFPLED prepared based on this process cannot work properly because the roughness of the AgNW electrode is large, and problems such as breakdown and conduction occur in the device, so it cannot work properly.
[0063] Figure 5 This is the large-area intrinsic flexible AgNW thin film electrode array prepared in Example 2 of the present invention, and this large-area intrinsic flexible AgNW thin film electrode array exhibits high optical transparency.
[0064] Figure 6 This is the relationship between the conductivity and stretchability of the intrinsic flexible AgNW thin film electrode prepared in Example 2. It can be seen that during the process of stretching from 0% to 100%, the conductivity does not decrease significantly, and after the stretching is released, it can still recover to a relatively high conductivity.
[0065] In Example 2, the IFPLED prepared with the intrinsic flexible AgNW thin film electrode obtained based on the electrospray printing process has high electroluminescence performance( Figure 7 ), and the brightness of the IFPLED does not show obvious attenuation with the increase of the tensile strain( Figure 8 ), showing good tensile resistance performance.
[0066] As can be seen from Figure 9 , for the AgNW thin film electrode prepared by the spin coating process, the maximum tensile strain is only 20%. However, for the intrinsic flexible AgNW thin film electrode prepared in Example 1 of the present invention, when stretched to a strain of 100% in the direction parallel to the electrodes, the resistivity increases to 8.4 times the original value. When stretched to a strain of 100% in the direction perpendicular to the electrodes, the resistivity increases to 5.3 times the original value.
[0067] The above experimental results show that the IFPLED based on the intrinsic flexible AgNW thin film electrode has high resistance to mechanical deformation, providing a simple and effective strategy for realizing intrinsic flexible display in the future.
[0068] Example 3: Based on the electrospray printing process, intrinsic flexible AgNW thin film electrodes are prepared at different ink extrusion rates and substrate moving rates
[0069] 1) Using a silicon wafer as the substrate, successively ultrasonic clean it with dishwashing liquid, deionized water, acetone and isopropanol for 10 min at a power of 50 W and a frequency of 30 kHz. After drying with a nitrogen gun, perform ultraviolet ozone treatment on the cleaned silicon wafer for 10 min at a power of 100 Hz to obtain a clean silicon wafer.
[0070] 2) Place the silicon wafer in step 1) on the sample stage of the electrospray printing instrument. Use a 2.5 ml glass syringe to extract AgNW ink (concentration 5 mg / ml, solvent is isopropanol). Set the ink extrusion rate to 100 μL / min, the substrate moving rate to 300 mm / s, the printing cycle to 1, the voltage between 5 kV and 7 kV, the spray needle model to 30G, and the distance between the spray needle and the substrate to 0.1 mm. Print the AgNW ink at room temperature to obtain a patterned intrinsic flexible AgNW thin film electrode, and the thickness of the thin film electrode is about 100 nm, as Figure 10 shown (left side).
[0071] 3) Change the ink extrusion rate in step 2) to 2 μL / min and the substrate moving rate to 1 mm / s, and keep other process conditions unchanged. Print the AgNW ink at room temperature to obtain a patterned intrinsic flexible AgNW thin film electrode, and the thickness of the thin film electrode is about 40 nm, as Figure 10 shown (right side).
[0072] This embodiment shows that the extrusion rate of the ink (2 - 100 μL / min) and the moving rate of the substrate (1 - 300 mm / s) can be adjusted within a large range, so as to control the line width and thickness of the intrinsic flexible AgNW thin film electrode.
Claims
1. A preparation method of an AgNW thin film electrode, comprising the following steps: Patterning and printing AgNW ink on a substrate by electrospray printing to obtain the AgNW thin film electrode.
2. The preparation method according to claim 1, wherein: The dispersion of the AgNW ink is water, ethanol or isopropanol; The concentration of the AgNW ink is 5 - 10 mg / mL; The length of the AgNW is 20 - 50 μm, and the diameter is 20 - 50 nm.
3. The preparation method according to claim 1 or 2, wherein: The conditions of the electrospray printing are as follows: The voltage is 1 - 10 kV, the needle type of the spray needle is one of 21G, 23G, 24G, 25G, 26G, 27G, 30G, 32G and 34G, the distance between the spray needle and the substrate is 0.1 - 0.5 mm, the extrusion rate of the ink is 2 - 100 μL / min, the moving rate of the substrate is 1 - 300 mm / s, and the printing cycle is 1 - 10 times.
4. The AgNW thin film electrode prepared by the method according to any one of claims 1 - 3; The thickness of the AgNW thin film electrode is 30 - 100 nm.
5. The application of the AgNW thin film electrode according to claim 4 in high - flexibility display devices, stretchable display devices and intrinsically flexible display devices.
6. An intrinsically flexible polymer light - emitting diode, comprising a substrate, a sacrificial layer, an elastomeric substrate, an intrinsically flexible anodic electrode, an intrinsically flexible hole - transporting layer, an intrinsically flexible light - emitting layer, an intrinsically flexible electron - transporting layer and an intrinsically flexible cathodic electrode which are arranged in sequence; Both the intrinsically flexible anodic electrode and the intrinsically flexible cathodic electrode are the AgNW thin film electrodes according to claim 4.
7. The intrinsically flexible polymer light - emitting diode according to claim 6, wherein: The substrate is selected from any one of silicon wafers, glass, ceramics and quartz; The sacrificial layer is selected from at least one of octadecyltrimethoxysilane, octadecyltrichlorosilane, octyltrichlorosilane and phenyltrichlorosilane, and is prepared by heat treatment under vacuum conditions or immersion treatment in a solution; The elastomeric substrate is prepared by solution spin - coating from any one of polyurethane elastomers, polydimethylsiloxane, hydrogenated styrene - butadiene block copolymer and styrene - butadiene rubber; The surface of the elastomeric substrate is treated by ultraviolet ozonation; The thickness of the elastomeric substrate is 0.3 mm - 2 mm.
8. The intrinsically flexible polymer light - emitting diode according to claim 6 or 7, wherein: The intrinsically flexible light - emitting layer is prepared by solution spin - coating from an intrinsically flexible hybrid polymer blend system; The intrinsically flexible hybrid polymer blend system is a blend of an elastomeric polymer and a light - emitting conjugated polymer. The luminescent conjugated polymer is any one of poly[{2,5-bis(3’,7’-dimethyloctyloxy)-1,4-phenyleneethynylene}-co-{3-(4’-(3”,7”-dimethyloctyloxy)phenyl)-1,4-phenyleneethynylene}-co-{3-(3’-(3”,7”-dimethyloctyloxy)phenyl)-1,4-phenyleneethynylene}], poly(9,9-dioctylfluorene-2,7-diyl), and poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenyleneethynylene]; The elastomeric polymer is any one of polyurethane elastomer, polydimethylsiloxane, hydrogenated styrene-butadiene block copolymer, and styrene-butadiene rubber; The mass ratio of the luminescent conjugated polymer to the elastomeric polymer is 1:9 to 5:5; The thickness of the intrinsic flexible light-emitting layer is 30 to 100 nm.
9. The intrinsic flexible polymer light-emitting diode according to any one of claims 6-8, characterized in that: The intrinsic flexible hole transport layer is prepared by solution spin coating from a blend of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid and any one of Triton-100, Triton-45, and sorbitol, with a ratio of 1:1 to 1:3; The intrinsic flexible electron transport layer is prepared by solution spin coating from a blend of polyethoxyethyleneimine and any one of zinc acetate dihydrate, 4,7-diphenyl-1,10-phenanthroline, and poly(9,9-bis(3’-(N,N-dimethyl)-N-ethylaminopropyl-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)) dibromide, with a ratio of 1:1 to 1:
5.
10. The intrinsic flexible polymer light-emitting diode according to any one of claims 6-9, characterized in that: The solvent of the solution used in the solution spin coating method is toluene, xylene, chlorobenzene, dichlorobenzene, chloroform, dichloromethane, tetrahydrofuran, dimethyl sulfoxide, N,N-dimethylformamide, methanol, ethanol, isopropanol, water, or n-hexane cyclohexane.