Intrinsic stretchable electroluminescent device and preparation method and application thereof

Abstract

The invention belongs to the field of photoelectric device display, and particularly relates to an intrinsic stretchable electroluminescent device and a preparation method and application thereof. The intrinsic stretchable electroluminescent device is composed of an intrinsic stretchable transparent substrate, an intrinsic stretchable transparent anode, an intrinsic stretchable hole injection / transmission layer, an intrinsic stretchable luminescent layer, an intrinsic stretchable electron injection / transmission layer, a metal cathode and liquid metal. Each layer is prepared independently, the liquid metal is deposited on the metal cathode through blade coating, spraying, dispensing printing and the like, and the other layers are deposited into a film through a solution method or a vacuum evaporation method; in the preparation process, the intrinsic tensile property of the device can be realized without special structures (such as wrinkles, island bridges, snakelike, paper-cut and the like), and the method has the advantages of simple process, low cost, wide application range and universality.

Description

Technical Field

[0001] The present invention belongs to the field of optoelectronic device display, and specifically relates to an intrinsically stretchable electroluminescent device and a preparation method and application thereof. Background Art

[0002] Flexible organic optoelectronic devices have evolved over the years, evolving from rigid, bendable, and foldable to the current stretchable state. Stretchable electroluminescent devices, a leading cutting-edge technology, demonstrate strong potential for applications in flexible displays, flexible lighting, healthcare, wearable smart devices, and other fields. These devices must withstand repeated bending, flexing, and stretching under high strain while maintaining virtually unchanged electrical properties.

[0003] Currently, optoelectronic device fabrication methods fall into two main categories: solution processing and vacuum evaporation. Solution processing includes spin coating, doctor blade coating, and inkjet printing. Small organic molecules and metals are well-suited for vacuum evaporation deposition, while polymers can only be processed into films using solution methods. Devices fabricated using vacuum evaporation offer superior performance, but suffer from low processing efficiency, low material utilization, and difficulty controlling the doping ratio. Conversely, solution processing offers the advantages of high processing efficiency, high material utilization, and precise control of the doping ratio. However, this requires the selection of a suitable good solvent and consideration of solvent orthogonality between adjacent layers, making fully solution-based devices difficult to implement. Currently, the more common approach is to use vacuum evaporation to deposit the electron injection / transport layer and metal cathode after the light-emitting layer. Due to limitations in film thickness and inherent material properties, devices fabricated using this method often begin to crack or break in the electron injection / transport layer and metal cathode when stretched, impacting device performance and even causing the device to fail to emit light. Summary of the Invention

[0004] The technical problems to be solved by the present invention are that the vacuum evaporation method in the prior art is difficult to apply to intrinsically stretchable electroluminescent devices, that intrinsically stretchable electroluminescent devices using a full solution method are difficult to realize, and that during the stretching process of solution-based stretchable electroluminescent devices, the electron injection / transport layer and the metal cathode begin to crack and break first, which hinders electron injection and thus affects the performance of the device. The present invention provides a method for depositing a layer of liquid metal on a metal cathode. During the stretching process of the device, when the electron injection / transport layer and the metal cathode begin to crack or break, the liquid metal can spontaneously fill the cracks or breaks, thereby playing a role in mechanical reinforcement. Another purpose of the present invention is to provide a method for preparing and applying an intrinsically stretchable electroluminescent device. The device prepared by this method can achieve intrinsic stretching without the aid of special structures (such as folds, island bridges, serpentines, and paper-cuts), and has the advantages of a simple preparation method, a wide range of applications, and universal applicability.

[0005] In order to solve the above technical problems, the present invention discloses an intrinsically stretchable electroluminescent device, which includes an intrinsically stretchable transparent substrate, an intrinsically stretchable transparent anode, an intrinsically stretchable hole injection / transport layer, an intrinsically stretchable light-emitting layer, an intrinsically stretchable electron injection / transport layer, a metal cathode and a liquid metal;

[0006] Among them, the intrinsic stretchable transparent anode is arranged on an intrinsic stretchable transparent substrate; the intrinsic stretchable transparent anode and the metal cathode are arranged opposite to each other; the intrinsic stretchable light-emitting layer is located between the intrinsic stretchable transparent anode and the metal cathode; an intrinsic stretchable hole injection / transport layer is provided between the intrinsic stretchable light-emitting layer and the intrinsic stretchable transparent anode; an intrinsic stretchable electron injection / transport layer is provided between the intrinsic stretchable light-emitting layer and the metal cathode; and liquid metal is also provided on the metal cathode.

[0007] Wherein, the liquid metal is a gallium-based alloy, including any one or more of gallium-aluminum alloy, gallium-tin alloy, gallium-antimony alloy, gallium-magnesium alloy and gallium-indium alloy;

[0008] In some embodiments of the present invention, the liquid metal is a gallium-indium alloy, specifically any one of gallium-indium alloys having melting points of 8° C., 11° C., 16° C., 21° C., and 29.8° C.

[0009] The intrinsically stretchable transparent substrate comprises any one or more of polydimethylsiloxane, thermoplastic polyurethane elastomer, styrene-butadiene-ethylene-butylene-styrene block copolymer, polyurethane acrylate and polyvinylidene fluoride.

[0010] Among them, the intrinsically stretchable transparent anode is composed of a conductive material; the conductive material includes any one or more of metal nanowires, metal grids, metal nanoparticles, and conductive polymers; the metal cathode includes any one or more of gold, silver, and aluminum.

[0011] Wherein, the luminescent material in the intrinsic stretchable luminescent layer includes any one of phosphorescent material, fluorescent material, thermally activated delayed fluorescent material and quantum dot material.

[0012] Among them, the hole injection / transport material in the intrinsic stretchable hole injection / transport layer includes any one of poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)fluorenyl-2,7-diyl)-alt-[(9,9-di-n-octylfluorenyl-2,7-diyl)-bromide, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) and poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(p-butylphenyl))diphenylamine)]; the electron injection / transport material in the intrinsic stretchable electron injection / transport layer is polyethyleneimine.

[0013] Furthermore, the method for preparing the intrinsically stretchable electroluminescent device is also within the scope of protection of the present invention, and comprises the following steps:

[0014] S1. depositing a conductive material on the surface of an intrinsically stretchable transparent substrate or blending a conductive material into the interior of the intrinsically stretchable transparent substrate to obtain an intrinsically stretchable transparent anode;

[0015] S2. Spin-coating a hole / injection transport material on the intrinsically stretchable transparent anode and annealing the material to prepare an intrinsically stretchable hole injection / transport layer on the intrinsically stretchable transparent anode, and repeating the spin-coating and annealing steps to prepare an intrinsically stretchable hole injection / transport layer on the intrinsically stretchable hole injection / transport layer;

[0016] S3. Spin-coating and annealing the intrinsic stretchable light-emitting layer to prepare an intrinsic stretchable hole injection / transport layer, followed by evaporation of a metal cathode;

[0017] S4. Depositing a layer of liquid metal on the surface of the metal cathode to obtain the intrinsically stretchable electroluminescent device.

[0018] Among them, in S1, the intrinsic stretchable transparent anode is deposited on the surface of the intrinsic stretchable transparent substrate by transfer, evaporation, spin coating, inkjet printing, spraying, doctor blade coating, photolithography, chemical vapor deposition, etc., or the conductive material is blended into the interior of the intrinsic stretchable transparent substrate by ultrasound, hot pressing, spraying, adding surfactants, modifying hydrophilic groups, etc.

[0019] In some embodiments of the present invention, in S2, the hole / injection transport material is poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) (PEDEOT:PSS), specifically a PEDEOT:PSS (AI 4083) solution doped with 5 wt% Triton-X and 1 wt% PFI; the specific spin coating process parameters of the hole / injection transport material are: rotation speed 3500 rpm, spin coating time 30 s; the specific annealing process of the hole / injection transport material is: annealing at 100 °C for 10 min.

[0020] In some embodiments of the present invention, in S2, the intrinsic stretchable light-emitting layer adopts poly(1,4-phenylene vinylene) copolymer (SuperYellow), specifically poly(1,4-phenylene vinylene) copolymer-toluene solution; the specific spin coating process parameters of the intrinsic stretchable light-emitting layer are: rotation speed 1500 rpm, spin coating time 30 s; the specific annealing process of the intrinsic stretchable light-emitting layer is: annealing at 100 °C for 10 min.

[0021] Among them, in S3, the spin coating process of the intrinsic stretchable hole injection / transport layer is: a rotation speed of 5000 rpm, and a spin coating time of 30 s; the annealing process of the intrinsic stretchable hole injection / transport layer is: annealing at 100°C for 10 minutes.

[0022] Wherein, in S4, the deposition method includes any one of spraying, scraping and dispensing printing.

[0023] Specifically, the caliber of the spray gun used for spraying is any one of 0.3 mm, 0.5 mm, 0.8 mm, and 1.0 mm.

[0024] Furthermore, the application of the above-mentioned intrinsic stretchable electroluminescent device in the preparation of intrinsic stretchable organic light-emitting diode devices and / or light-emitting electrochemical devices is also within the protection scope of the present invention; wherein, the intrinsic stretchable organic light-emitting diode device is used in display, lighting, sensing and other fields.

[0025] Specifically, in some embodiments of the present invention, an intrinsic stretchable electroluminescent device is prepared by the above-mentioned preparation method. By comparing the efficiency-brightness and the resistance change under different strains with the device without liquid metal spraying, it is shown that the liquid metal in the intrinsic stretchable electroluminescent device after spraying liquid metal can spontaneously fill the cracks or breaks after stretching, playing a role of mechanical reinforcement and conductivity, which proves the application prospect of intrinsic stretchable electroluminescent devices in the preparation of intrinsic stretchable organic light-emitting diode devices and / or light-emitting electrochemical devices.

[0026] The technical principle of this application is: during the stretching process of the stretchable electroluminescent device prepared by the solution method, cracks begin to appear in the electron injection / transport layer and the metal cathode. A layer of liquid metal is deposited on the metal cathode, so that during the stretching process of the device, when cracks or fractures begin to appear in the electron injection / transport layer and the metal cathode, the liquid metal can spontaneously fill the cracks or fractures, thereby playing a role in mechanical reinforcement and conductivity.

[0027] Beneficial effects:

[0028] During the stretching process of a solution-based stretchable electroluminescent device, the electron injection / transport layer and the metal cathode first begin to crack and break, which hinders electron injection and thus affects the device performance. To address this problem, the present application proposes depositing a layer of liquid metal on the metal cathode. During the stretching process of the device, when the electron injection / transport layer and the metal cathode begin to crack or break, the liquid metal can spontaneously fill the cracks or breaks, thereby playing a role in mechanical reinforcement and conductivity.

[0029] Currently, stretchable electroluminescent devices mostly use structural engineering (such as folds, island bridges, serpentines, paper cutting, etc.) to achieve the stretchability of the devices, and these processes are relatively complex; this application proposes a strategy to achieve the intrinsic stretchability of the device by depositing a layer of liquid metal on the metal cathode, which only involves spraying, scraping, dispensing printing and other technologies, and has the advantages of simple process, low cost, wide application range and universality.

[0030] The intrinsically stretchable electroluminescent device prepared in this application can be used in flexible display, flexible lighting, wearable devices and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more apparent.

[0032] Figure 1 Schematic diagram of the intrinsic stretchable electroluminescent device provided by the present invention.

[0033] Figure 2 Microscopic morphology of the liquid metal sprayed on the intrinsic stretchable device prepared in Example 3.

[0034] Figure 3 This is a comparison diagram of the efficiency-brightness of the intrinsic stretchable electroluminescent devices with and without liquid metal spraying prepared in Example 3 of the present invention and the comparative example.

[0035] Figure 4 3 is a comparison chart of the resistance change under different strains of the electrodes sprayed with and not sprayed with liquid metal prepared in Example 3 of the present invention and the comparative example. DETAILED DESCRIPTION

[0036] The experimental methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials are commercially available unless otherwise specified.

[0037] The present invention provides an intrinsically stretchable electroluminescent device, the specific structure of which is as follows Figure 1 As shown, the intrinsically stretchable electroluminescent device includes an intrinsically stretchable transparent substrate, an intrinsically stretchable transparent anode, an intrinsically stretchable hole injection / transport layer, an intrinsically stretchable light-emitting layer, an intrinsically stretchable electron injection / transport layer, a metal cathode, and a liquid metal. The intrinsically stretchable transparent anode is disposed on the intrinsically stretchable transparent substrate, the intrinsically stretchable transparent anode and the metal cathode are disposed opposite each other, the intrinsically stretchable light-emitting layer is located between the intrinsically stretchable transparent anode and the metal cathode, an intrinsically stretchable hole injection / transport layer is disposed between the intrinsically stretchable light-emitting layer and the intrinsically stretchable transparent anode, an intrinsically stretchable electron injection / transport layer is disposed between the intrinsically stretchable light-emitting layer and the metal cathode, and liquid metal is further disposed on the metal cathode.

[0038] The intrinsically stretchable transparent substrate comprises any one or more of polydimethylsiloxane, thermoplastic polyurethane elastomer, styrene-butadiene-ethylene-butylene-styrene block copolymer, polyurethane acrylate, and polyvinylidene fluoride.

[0039] The intrinsically stretchable transparent anode is composed of a conductive material, and the conductive material includes any one or more of metal nanowires, metal grids, metal nanoparticles, and conductive polymers.

[0040] The intrinsically stretchable hole injection / transport layer includes any one of poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)fluorenyl-2,7-diyl)-alt-[(9,9-di-n-octylfluorenyl-2,7-diyl)-bromide, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) and poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(p-butylphenyl))diphenylamine)].

[0041] The intrinsic stretchable light-emitting layer includes any one of a phosphorescent material, a fluorescent material, a thermally activated delayed fluorescent material and a quantum dot material.

[0042] The intrinsically stretchable electron injection / transport layer is polyethyleneimine.

[0043] The metal cathode includes any one or more of gold, silver and aluminum.

[0044] The liquid metal is a gallium-indium alloy, specifically any one of gallium-indium alloys with melting points of 8°C, 11°C, 16°C, 21°C, and 29.8°C. The liquid metal is deposited by spraying, scraping, or dispensing. The spray gun used for spraying has a caliber of 0.3 mm, 0.5 mm, 0.8 mm, or 1.0 mm.

[0045] The present invention also provides a method for preparing an intrinsically stretchable electroluminescent device, comprising the following steps:

[0046] S1. depositing a conductive material on the surface of an intrinsically stretchable transparent substrate or blending a conductive material into the interior of the intrinsically stretchable transparent substrate to obtain an intrinsically stretchable transparent substrate and an intrinsically stretchable transparent anode;

[0047] S2. Spin-coating a hole / injection transport material on the intrinsically stretchable transparent anode and annealing the material to prepare an intrinsically stretchable hole injection / transport layer on the intrinsically stretchable transparent anode, and repeating the spin-coating and annealing steps to prepare an intrinsically stretchable hole injection / transport layer on the intrinsically stretchable hole injection / transport layer;

[0048] S3. Spin-coating an intrinsically stretchable hole injection / transport layer and an evaporated metal cathode on the intrinsically stretchable light-emitting layer;

[0049] S4. depositing a layer of liquid metal on the surface of the metal cathode to obtain the intrinsic stretchable electroluminescent device.

[0050] Example 1:

[0051] A method for preparing an intrinsic stretchable electroluminescent device, comprising the following steps:

[0052] First step: spin-coat a silver nanowire-isopropyl alcohol solution with a concentration of 2 mg / mL on a cleaned glass or silicon wafer and patternize to obtain a conductive film with a thickness of 100-400 nm;

[0053] Second step: mix PDMS and cross-linking agent at a mass ratio of 10:1, stir uniformly, and then place in a vacuum environment for 30 min to remove bubbles in the liquid PDMS. Pour the liquid bubble-free PDMS on the conductive film, remove the excess PDMS by spin-coating, and then solidify at 60 °C for 6 h. Finally, remove the intrinsic stretchable transparent anode from deionized water, and the thickness is 100-500 μm;

[0054] Third step: spin-coat a poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate (PEDOT:PSS, AI 4083) solution doped with 5 wt% polyethylene glycol octylphenyl ether (Triton-X) and 1 wt% tetrafluoroethylene-perfluoro-3,6-dioxa-4-methyl-7-octene sulfonic acid copolymer (PFI) on the intrinsic stretchable transparent anode at a speed of 3500 rpm for 30 s, and then anneal at 100 °C for 10 min to obtain an intrinsic stretchable hole injection / transport layer with a thickness of about 20 nm;

[0055] Fourth step: spin-coat a poly(1,4-phenylenevinylene) copolymer (SuperYellow)-toluene solution with a concentration of 6 mg / mL on the intrinsic stretchable hole injection / transport layer at a speed of 1500 rpm for 30 s, and then anneal at 100 °C for 10 min to obtain an intrinsic stretchable light-emitting layer with a thickness of about 40 nm;

[0056] Fifth step: spin-coat a polyethyleneimine (PEI) isopropyl alcohol solution with a concentration of 0.2 mg / mL on the intrinsic stretchable light-emitting layer at a speed of 5000 rpm for 30 s, and then anneal at 100 °C for 10 min to obtain an intrinsic stretchable electron injection / transport layer with a thickness of about 10 nm. Finally, evaporate 100 nm of Al as a cathode by vacuum evaporation;

[0057] Step 6: Use a 0.8 mm caliber spray gun to spray liquid metal with a melting point of 21°C on the surface of the metal cathode with a thickness of about 10 nm, and finally obtain an intrinsically stretchable light-emitting device.

[0058] Example 2:

[0059] A method for preparing an intrinsically stretchable electroluminescent device comprises the following steps:

[0060] Step 1: Spin-coat a 2 mg / mL silver nanowire-isopropyl alcohol solution onto a cleaned glass or silicon wafer and pattern it to produce a conductive film with a thickness of 100-400 nm.

[0061] Step 2: 600-1000 μL of 130 mg / mL TPU-DMF solution was poured onto the conductive film, cured at 60°C for 3 h, and then peeled off under deionized water to obtain an intrinsically stretchable transparent anode with a thickness of 100-500 μm.

[0062] Step 3: Spin-coat a PEDEOT:PSS (AI 4083) solution doped with 5 wt% Triton-X and 1 wt% PFI onto the intrinsically stretchable transparent anode at 3500 rpm for 30 s. After spin-coating, anneal the solution at 100 °C for 10 min to obtain an intrinsically stretchable hole injection / transport layer with a thickness of approximately 20 nm.

[0063] Step 4: Spin-coat a 6 mg / mL poly(1,4-phenylene vinylene) copolymer (SuperYellow)-toluene solution on the intrinsically stretchable hole injection / transport layer at 1500 rpm for 30 s. After spin coating, anneal the solution at 100°C for 10 min to obtain an intrinsically stretchable light-emitting layer with a thickness of approximately 40 nm.

[0064] Step 5: Spin-coat a 0.2 mg / mL polyethyleneimine (PEI)-isopropanol solution on the intrinsically stretchable light-emitting layer at 5000 rpm for 30 s. After spin-coating, anneal the layer at 100°C for 10 min to obtain an intrinsically stretchable electron injection / transport layer with a thickness of approximately 10 nm. Finally, vacuum evaporate 100 nm of Al as the cathode.

[0065] Step 6: Use a 0.8 mm caliber spray gun to spray liquid metal with a melting point of 21°C on the surface of the metal cathode with a thickness of about 10 nm, and finally obtain an intrinsically stretchable light-emitting device.

[0066] Example 3:

[0067] A method for preparing an intrinsically stretchable electroluminescent device comprises the following steps:

[0068] Step 1: Pour 600-1000 μL of a 130 mg / mL TPU-DMF solution onto a clean glass or silicon wafer and cure at 60°C for 3 h to obtain an intrinsically stretchable transparent substrate with a thickness of 100-500 μm.

[0069] Step 2: Spin-coating a PEDOT:PSS solution doped with 5 wt% Triton-X onto a TPU substrate to obtain an intrinsically stretchable transparent anode.

[0070] Step 3: Spin-coat a PEDEOT:PSS (AI 4083) solution doped with 5 wt% Triton-X and 1 wt% PFI onto the intrinsically stretchable transparent anode at 3500 rpm for 30 s. After spin-coating, anneal the solution at 100 °C for 10 min to obtain an intrinsically stretchable hole injection / transport layer with a thickness of approximately 20 nm.

[0071] Step 4: Spin-coat a 6 mg / mL poly(1,4-phenylene vinylene) copolymer (SuperYellow)-toluene solution on the intrinsically stretchable hole injection / transport layer at 1500 rpm for 30 s. After spin coating, anneal the solution at 100°C for 10 min to obtain an intrinsically stretchable light-emitting layer with a thickness of approximately 40 nm.

[0072] Step 5: Spin-coat a 0.2 mg / mL polyethyleneimine (PEI)-isopropanol solution on the intrinsically stretchable light-emitting layer at 5000 rpm for 30 s. After spin-coating, anneal the layer at 100°C for 10 min to obtain an intrinsically stretchable electron injection / transport layer with a thickness of approximately 10 nm. Finally, vacuum evaporate 100 nm of Al as the cathode.

[0073] Step 6: Use a 0.8 mm caliber spray gun to spray liquid metal with a melting point of 21°C on the surface of the metal cathode with a thickness of about 20 nm, and finally obtain an intrinsically stretchable light-emitting device.

[0074] Example 4:

[0075] A method for preparing an intrinsically stretchable electroluminescent device comprises the following steps:

[0076] Step 1: Pour 600-1000 μL of a 200 mg / mL SEBS-toluene solution onto a clean glass or silicon wafer and cure it at 60°C for 5 hours to form a stretchable transparent substrate with a thickness of 100-500 μm.

[0077] Step 2: Add 5 wt% Triton-X to PEDOT:PSS and prepare an intrinsically stretchable transparent anode on a SEBS elastic substrate by blade coating with a thickness of 100-400 nm;

[0078] Step 3: Spin-coat a PEDEOT:PSS (AI 4083) solution doped with 5 wt% Triton-X and 1 wt% PFI onto the intrinsically stretchable transparent anode at 3500 rpm for 30 s. After spin-coating, anneal the solution at 100 °C for 10 min to obtain an intrinsically stretchable hole injection / transport layer with a thickness of approximately 20 nm.

[0079] Step 4: Spin-coat a 6 mg / mL poly(1,4-phenylene vinylene) copolymer (SuperYellow)-toluene solution on the intrinsically stretchable hole injection / transport layer at 1500 rpm for 30 s. After spin coating, anneal the solution at 100°C for 10 min to obtain an intrinsically stretchable light-emitting layer with a thickness of approximately 40 nm.

[0080] Step 5: Spin-coat a 0.2 mg / mL polyethyleneimine (PEI)-isopropanol solution on the intrinsically stretchable light-emitting layer at 5000 rpm for 30 s. After spin-coating, anneal the layer at 100°C for 10 min to obtain an intrinsically stretchable electron injection / transport layer with a thickness of approximately 10 nm. Finally, vacuum evaporate 100 nm of Al as the cathode.

[0081] Step 6: The treated liquid metal is loaded into a syringe, air bubbles are expelled, and several initial dispensing steps are performed to ensure smooth liquid metal flow and effective destruction of the oxide layer. The needle gently touches the metal cathode, utilizing the adhesion between the liquid metal oxide film and the substrate to achieve patterning. The dispensing path is programmed according to the designed pattern, resulting in a liquid metal layer approximately 10 nm thick, ultimately creating an intrinsically stretchable light-emitting device.

[0082] Example 5:

[0083] A method for preparing an intrinsically stretchable electroluminescent device comprises the following steps:

[0084] Step 1: Spin-coat a 10 mg / mL graphene solution onto a cleaned glass or silicon wafer and pattern it to produce a conductive film with a thickness of 100-400 nm.

[0085] Step 2: Pour 600-1000 μL of 150 mg / mL PVDF-HFP elastomer solution onto the conductive film and cure it at 80°C for 2 h to prepare an intrinsically stretchable transparent anode.

[0086] Step 3: Spin-coat a PEDEOT:PSS (AI 4083) solution doped with 5 wt% Triton-X and 1 wt% PFI onto the intrinsically stretchable transparent anode at 3500 rpm for 30 s. After spin-coating, anneal the solution at 100 °C for 10 min to obtain an intrinsically stretchable hole injection / transport layer with a thickness of approximately 20 nm.

[0087] Step 4: Spin-coat a 6 mg / mL poly(1,4-phenylene vinylene) copolymer (SuperYellow)-toluene solution on the intrinsically stretchable hole injection / transport layer at 1500 rpm for 30 s. After spin coating, anneal the solution at 100°C for 10 min to obtain an intrinsically stretchable light-emitting layer with a thickness of approximately 40 nm.

[0088] Step 5: Spin-coat a 0.2 mg / mL polyethyleneimine (PEI)-isopropanol solution on the intrinsically stretchable light-emitting layer at 5000 rpm for 30 s. After spin-coating, anneal the layer at 100°C for 10 min to obtain an intrinsically stretchable electron injection / transport layer with a thickness of approximately 10 nm. Finally, vacuum evaporate 100 nm of Al as the cathode.

[0089] Step 6: The treated liquid metal is loaded into a syringe, air bubbles are expelled, and several initial dispensing steps are performed to ensure smooth liquid metal flow and effective destruction of the oxide layer. The needle gently touches the metal cathode, utilizing the adhesion between the liquid metal oxide film and the substrate to achieve patterning. The dispensing path is programmed according to the designed pattern, resulting in a liquid metal layer approximately 10 nm thick, ultimately creating an intrinsically stretchable light-emitting device.

[0090] Example 6:

[0091] A method for preparing an intrinsically stretchable electroluminescent device comprises the following steps:

[0092] Step 1: Spin-coat a 10 mg / mL graphene solution onto a cleaned glass or silicon wafer and pattern it to produce a conductive film with a thickness of 100-400 nm.

[0093] Step 2: Pour 600-1000 μL of 150 mg / mL PVDF-HFP elastomer solution onto the conductive film and cure it at 80°C for 2 h to prepare an intrinsically stretchable transparent anode.

[0094] Step 3: Spin-coat a PEDEOT:PSS (AI 4083) solution doped with 5 wt% Triton-X and 1 wt% PFI onto the intrinsically stretchable transparent anode at 3500 rpm for 30 s. After spin-coating, anneal the solution at 100 °C for 10 min to obtain an intrinsically stretchable hole injection / transport layer with a thickness of approximately 20 nm.

[0095] Step 4: Spin-coat a 6 mg / mL poly(1,4-phenylene vinylene) copolymer (SuperYellow)-toluene solution on the intrinsically stretchable hole injection / transport layer at 1500 rpm for 30 s. After spin coating, anneal the solution at 100°C for 10 min to obtain an intrinsically stretchable light-emitting layer with a thickness of approximately 40 nm.

[0096] Step 5: Spin-coat a 0.2 mg / mL polyethyleneimine (PEI)-isopropanol solution on the intrinsically stretchable light-emitting layer at 5000 rpm for 30 s. After spin-coating, anneal the layer at 100°C for 10 min to obtain an intrinsically stretchable electron injection / transport layer with a thickness of approximately 10 nm. Finally, vacuum evaporate 100 nm of Al as the cathode.

[0097] Step 6: Scrape liquid metal on the surface of the metal cathode at a speed of 30° and 10 mm / s, with a thickness of about 20 nm, to finally obtain an intrinsically stretchable light-emitting device.

[0098] Example 7:

[0099] A method for preparing an intrinsically stretchable electroluminescent device comprises the following steps:

[0100] Step 1: inkjet print silver nanoparticle ink with a concentration of 20 mg / mL onto cleaned glass or silicon wafers to form a metal grid pattern with a thickness of 100-400 nm.

[0101] Step 2: Pour 600-1000 μL of 150 mg / mL TPU-DMF solution onto the metal grid pattern, cure it at 60°C for 5 h, and then peel it off in deionized water to obtain an intrinsically stretchable transparent anode with a thickness of 100-500 μm.

[0102] Step 3: Spin-coat a PEDEOT:PSS (AI 4083) solution doped with 5 wt% Triton-X and 1 wt% PFI onto the intrinsically stretchable transparent anode at 3500 rpm for 30 s. After spin-coating, anneal the solution at 100 °C for 10 min to obtain an intrinsically stretchable hole injection / transport layer with a thickness of approximately 20 nm.

[0103] Step 4: Spin-coat a 6 mg / mL poly(1,4-phenylene vinylene) copolymer (SuperYellow)-toluene solution on the intrinsically stretchable hole injection / transport layer at 1500 rpm for 30 s. After spin coating, anneal the solution at 100°C for 10 min to obtain an intrinsically stretchable light-emitting layer with a thickness of approximately 40 nm.

[0104] Step 5: Spin-coat a 0.2 mg / mL polyethyleneimine (PEI)-isopropanol solution on the intrinsically stretchable light-emitting layer at 5000 rpm for 30 s. After spin-coating, anneal the layer at 100°C for 10 min to obtain an intrinsically stretchable electron injection / transport layer with a thickness of approximately 10 nm. Finally, vacuum evaporate 100 nm of Al as the cathode.

[0105] Step 6: Scrape liquid metal on the surface of the metal cathode at a speed of 30° and 10 mm / s, with a thickness of about 20 nm, to finally obtain an intrinsically stretchable light-emitting device.

[0106] Example 8:

[0107] A method for preparing an intrinsically stretchable electroluminescent device comprises the following steps:

[0108] Step 1: inkjet print silver nanoparticle ink with a concentration of 20 mg / mL onto cleaned glass or silicon wafers to form a metal grid pattern with a thickness of 100-400 nm.

[0109] Step 2: Pour 600-1000 μL of 150 mg / mL TPU-DMF solution on the metal grid pattern, cure it at 60°C for 5 h, and then peel it off in deionized water to obtain an intrinsically stretchable transparent anode with a thickness of 100-500 μm.

[0110] Step 3: Spin-coat a PEDEOT:PSS (AI 4083) solution doped with 5 wt% Triton-X and 1 wt% PFI onto the intrinsically stretchable transparent anode at 3500 rpm for 30 s. After spin-coating, anneal the solution at 100 °C for 10 min to obtain an intrinsically stretchable hole injection / transport layer with a thickness of approximately 20 nm.

[0111] Step 4: Spin-coat a 6 mg / mL poly(1,4-phenylene vinylene) copolymer (SuperYellow)-toluene solution on the intrinsically stretchable hole injection / transport layer at 1500 rpm for 30 s. After spin coating, anneal the solution at 100°C for 10 min to obtain an intrinsically stretchable light-emitting layer with a thickness of approximately 40 nm.

[0112] Step 5: Spin-coat a 0.2 mg / mL polyethyleneimine (PEI)-isopropanol solution on the intrinsically stretchable light-emitting layer at 5000 rpm for 30 s. After spin-coating, anneal the layer at 100°C for 10 min to obtain an intrinsically stretchable electron injection / transport layer with a thickness of approximately 10 nm. Finally, vacuum evaporate 100 nm of Al as the cathode.

[0113] Step 6: Use a 0.8 mm caliber spray gun to spray liquid metal with a melting point of 21°C on the surface of the metal cathode with a thickness of about 10 nm, and finally obtain an intrinsically stretchable light-emitting device.

[0114] Comparative Example 1:

[0115] An intrinsically stretchable electroluminescent device was prepared by the preparation method of Reference Example 3, except that no liquid metal was provided above the metal cathode in this comparative example.

[0116] First, the microscopic morphology of the liquid metal sprayed on the intrinsically stretchable device prepared in Example 3 was characterized. Figure 2 The microscopic morphology of the liquid metal sprayed on the intrinsic stretchable device prepared in Example 3 is shown in FIG. Figure 2 It can be seen that the liquid metal is stably deposited on the surface of the Al electrode.

[0117] The intrinsic stretchable electroluminescent devices prepared in Example 3 and the comparative example were further subjected to current efficiency-brightness tests and electrode square resistance and strain tests. Figure 3 is the current efficiency-luminance curve of the intrinsic stretchable electroluminescent device, Figure 4 is the relationship curve between electrode square resistance and strain. Figure 4 It can be seen that after a layer of liquid metal is deposited on Al, a transverse tensile stress is applied to the electrode, the electrode is strained, and its square resistance hardly changes. In contrast, the square resistance of the Al electrode without liquid metal deposition increases sharply with strain. Figure 3 This also reflects the gain effect of liquid metal on the device. Devices without liquid metal deposition will have lower current efficiency than devices with liquid metal deposition during the stretching process due to the increase in the sheet resistance of the Al electrode. In addition, because liquid metal can flow spontaneously and fill the small cracks in the Al during the stretching process, devices with liquid metal deposition will have higher brightness.

[0118] The present invention provides an intrinsically stretchable electroluminescent device, its preparation method, and its application. There are many specific methods and approaches to implement this technical solution. The above is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention. Such improvements and modifications should also be considered within the scope of protection of the present invention. Any components not specified in this embodiment can be implemented using existing technologies.

Claims

1. An intrinsically stretchable electroluminescent device, characterized in that: The intrinsic stretchable electroluminescent device comprises an intrinsic stretchable transparent substrate, an intrinsic stretchable transparent anode, an intrinsic stretchable hole injection / transport layer, an intrinsic stretchable light-emitting layer, an intrinsic stretchable electron injection / transport layer, a metal cathode and a liquid metal; Among them, the intrinsic stretchable transparent anode is arranged on an intrinsic stretchable transparent substrate; the intrinsic stretchable transparent anode and the metal cathode are arranged opposite to each other; the intrinsic stretchable light-emitting layer is located between the intrinsic stretchable transparent anode and the metal cathode; an intrinsic stretchable hole injection / transport layer is provided between the intrinsic stretchable light-emitting layer and the intrinsic stretchable transparent anode; an intrinsic stretchable electron injection / transport layer is provided between the intrinsic stretchable light-emitting layer and the metal cathode; and liquid metal is also provided on the metal cathode.

2. The intrinsically stretchable electroluminescent device according to claim 1, characterized in that: The liquid metal is a gallium-based alloy, including any one or more of gallium-aluminum alloy, gallium-tin alloy, gallium-antimony alloy, gallium-magnesium alloy and gallium-indium alloy.

3. The intrinsically stretchable electroluminescent device according to claim 1, characterized in that: The intrinsically stretchable transparent substrate includes any one or more of polydimethylsiloxane, thermoplastic polyurethane elastomer, styrene-butadiene-ethylene-butylene-styrene block copolymer, polyurethane acrylate and polyvinylidene fluoride.

4. The intrinsically stretchable electroluminescent device according to claim 1, characterized in that The intrinsically stretchable transparent anode is composed of a conductive material; the conductive material includes any one or more of metal nanowires, metal grids, metal nanoparticles, and conductive polymers; the metal cathode includes any one or more of gold, silver, and aluminum.

5. The intrinsically stretchable electroluminescent device according to claim 1, characterized in that: The luminescent material in the intrinsic stretchable luminescent layer includes any one of a phosphorescent material, a fluorescent material, a thermally activated delayed fluorescent material and a quantum dot material.

6. The intrinsically stretchable electroluminescent device according to claim 1, characterized in that: The hole injection / transport material in the intrinsic stretchable hole injection / transport layer includes any one of poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)fluorenyl-2,7-diyl)-alt-[(9,9-di-n-octylfluorenyl-2,7-diyl)-bromide, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) and poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(p-butylphenyl))diphenylamine)]; the electron injection / transport material in the intrinsic stretchable electron injection / transport layer is polyethyleneimine.

7. The method for preparing an intrinsically stretchable electroluminescent device according to any one of claims 1 to 6, characterized in that: The steps include: S1. depositing a conductive material on the surface of an intrinsically stretchable transparent substrate or blending a conductive material into the interior of the intrinsically stretchable transparent substrate to obtain an intrinsically stretchable transparent anode; S2. Spin-coating a hole / injection transport material on the intrinsically stretchable transparent anode and annealing the material to prepare an intrinsically stretchable hole injection / transport layer on the intrinsically stretchable transparent anode, and repeating the spin-coating and annealing steps to prepare an intrinsically stretchable hole injection / transport layer on the intrinsically stretchable hole injection / transport layer; S3. Spin-coating and annealing the intrinsic stretchable light-emitting layer to prepare an intrinsic stretchable hole injection / transport layer, followed by evaporation of a metal cathode; S4. Depositing a layer of liquid metal on the surface of the metal cathode to obtain the intrinsically stretchable electroluminescent device.

8. The preparation method according to claim 7, characterized in that In S4, the deposition method includes any one of spraying, scraping and dispensing printing.

9. The preparation method according to claim 8, characterized in that The caliber of the spray gun used for spraying is any one of 0.3 mm, 0.5 mm, 0.8 mm, and 1.0 mm.

10. Use of the intrinsically stretchable electroluminescent device according to any one of claims 1 to 6 in the preparation of organic light emitting diode devices and / or light emitting electrochemical devices.

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