A fibrous quantum dot electroluminescent device and a method for preparing the same

Abstract

The present application belongs to the field of flexible electronic devices, and particularly relates to a fiber-like quantum dot electroluminescent device and a preparation method thereof. The electroluminescent device of the present application is formed by a spiral structure of multiple layers of materials, and from the outer layer to the inner layer, the spiral structure comprises a polymer flexible substrate, a stress buffer layer, an anode layer of high work function material, a hole injection layer for reducing the potential barrier to be overcome in the transmission process of holes, a hole transport layer for optimizing the efficiency of holes into the light-emitting layer, a quantum dot light-emitting layer for the recombination of holes and electrons to emit light, an electron transport layer for optimizing the efficiency of electrons into the light-emitting layer and blocking the further transmission of holes, and a cathode layer of low work function material. The special laminated structure of the present application realizes the self-packaging and stress dispersion of the device, improves the stability of the device in operation, and the obtained fiber-like electroluminescent device has a brightness of more than 50000 cd / m 2 , high color purity, good flexibility, strong stability, and has a wide application prospect in the field of flexible electronic devices.

Description

Technical Field

[0001] This invention belongs to the field of flexible electronic device technology, specifically relating to a fiber-shaped quantum dot electroluminescent device and its preparation method. Background Technology

[0002] With the rapid development of wearable electronic devices, flexible electronic devices have become a hot research topic in academia and industry as ideal carriers. Their high degree of conformity to the human body and lightweight design are crucial factors, determining the adaptability requirements of flexible electronic devices in human-computer interaction applications. Fiber-shaped electronic devices can meet high curvature deformation requirements and achieve even greater conformity to the human body. Furthermore, fiber structures endow devices with smaller volume, higher light-emitting surface area, and better space utilization, while also possessing a degree of implantability, making them a promising candidate for application in the field of smart wearables.

[0003] Traditional light-emitting materials include light-emitting diodes (LEDs) and organic light-emitting diodes (OLEDs). With the rise of smart wearable devices such as display fabrics, fiber-optic light-emitting devices are constantly innovating and developing, mainly based on alternating current electroluminescent devices (ACELs) and polymer light-emitting electrochemical cells (PLECs). However, ACEL devices have high turn-on voltages, resulting in severe crosstalk when woven into fabric displays, and their brightness is relatively low; PLEC devices have low brightness and short lifespan; while OLED devices have poor material continuity, are prone to cracking, and have low compatibility with fiber structures. Quantum dot light-emitting diodes (QLEDs), as a new generation of light-emitting materials, have advantages such as high brightness, wide color gamut, high stability, and simple processing. Furthermore, the materials in quantum dot electroluminescent devices are mostly nanoparticles or polymers, which, due to their inherent good ductility and high film-forming properties, have become the best choice for fiber-optic light-emitting device materials.

[0004] This invention utilizes a roll-up method to shape a planar light-emitting device into a spiral coaxial fiber structure, resulting in an electroluminescent device. This unique structure retains the excellent performance of planar devices while also imparting flexibility. Furthermore, the layered structure design enables self-encapsulation, solving the stringent encapsulation challenges of quantum dot materials. Simultaneously, the introduction of a stress-buffering layer is amplified by the special layered structure, further optimizing the device's mechanical properties and enhancing its flexibility. These features expand the application scenarios of this fiber-shaped quantum dot electroluminescent device and increase its potential to drive the development of flexible electronic devices. Summary of the Invention

[0005] The purpose of this invention is to provide a high-brightness, high-color-purity flexible fiber-shaped quantum dot electroluminescent device and its preparation method, overcoming the limitations of existing electroluminescent devices (LED, OLED, ACEL, PLEC) in terms of materials and preparation processes, and the difficulty in preparing high-performance fiber-shaped electroluminescent devices.

[0006] The fibrous quantum dot electroluminescent device provided by this invention comprises a spiral structure formed by rolling multiple layers of materials (the planar device is rolled into a fibrous shape like sushi, i.e., the planar material is spirally rolled into fibers, and the internal structure of the fibers is spiral-shaped), and its cross-section is as follows. Figure 1 As shown; from the outermost layer inwards are: (1) flexible substrate, which is a polymer material; (2) stress buffer layer (including polymer stress buffer layer and metal oxide smooth buffer layer); (3) anode layer, which is a high work function material; (4) hole injection layer, which is used to reduce the potential barrier that holes need to overcome during the transmission process; (5) hole transport layer, which is used to optimize the efficiency of hole transmission to the light-emitting layer; (6) quantum dot light-emitting layer, where holes and electrons recombine to emit light; (7) electron transport layer, which is used to optimize the efficiency of electron transmission to the light-emitting layer, while blocking further hole transmission; (8) cathode layer, which is a low work function material.

[0007] This invention also proposes a method for fabricating the above-mentioned fibrous quantum dot electroluminescent device, the specific steps of which are as follows:

[0008] (1) A flexible polymer substrate was prepared on a sheet material by spin coating;

[0009] (2) A polymer stress buffer layer and a metal oxide smoothing buffer layer are sequentially prepared on a flexible substrate;

[0010] (3) The anode layer, hole injection layer, hole transport layer, quantum dot light-emitting layer, electron transport layer and cathode layer of the quantum dot light-emitting device are sequentially prepared on the metal oxide smooth buffer layer;

[0011] (4) The obtained planar quantum dot light-emitting device is rolled into shape by a film rolling process to obtain a fiber quantum dot electroluminescent device with a spiral internal structure.

[0012] Furthermore:

[0013] In step (1), the sheet material is polyethylene terephthalate (PET), polypropylene (PP), or silicon wafer; the flexible polymer substrate material is silicone rubber (PDMS-RT601), ethylene-ethylene-butene-styrene block copolymer (SEBS), or polyimide (PI); the thickness of the flexible polymer substrate is 20-100 μm, preferably 50-100 μm. In the spin coating method, the spin coating speed is 1000-5000 rpm, the time is 40-120 s, and the acceleration is 100-1000 rpm / s.

[0014] In step (2), the polymer stress buffer layer material is polyvinyl alcohol (PVA), polystyrene (PS) or parylene; it is prepared on a flexible substrate by spin coating or chemical vapor deposition (CVD), and the thickness of the polymer stress buffer layer is 0.5-10 μm, preferably 5-10 μm.

[0015] The spin coating speed is 2000-4000 rpm, the time is 20-60 s, and the acceleration is 200-800 rpm / s; the material mass of CVD is 0.5-1.5 g, preferably 0.8-1.2 g.

[0016] In step (2), the metal oxide smoothing buffer layer material is one of molybdenum oxide and zinc oxide; the thickness of the metal oxide smoothing buffer layer is 5-15 nm, preferably 10-15 nm. It is prepared by vacuum thermal evaporation or magnetron sputtering.

[0017] In step (3):

[0018] The anode layer material is gold, indium tin oxide (ITO), aluminum-doped zinc oxide, or a high work function metal; it is prepared by vacuum thermal evaporation or magnetron sputtering, and the anode layer thickness is 10-30 nm, preferably 15-20 nm.

[0019] The hole injection layer material is poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT: PSS), MoO3, or NiO; the hole injection layer thickness is 10-20 nm; it is prepared by spin coating: the spin coating speed is 2000-4000 rpm, the time is 20-60 s, the acceleration is 200-800 rpm / s, and the annealing temperature is 50-60 ℃; or it is prepared by vacuum thermal evaporation, with a deposition rate of 0.2-0.5 Å / s, preferably 0.3-0.45 Å / s;

[0020] The hole transport layer material is poly[(9,9-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine)] (TFB), poly[(9,9-dioctylfluorene-2,7-diyl)-alternating-(4,4'-(N-(4-(1,1,1,3,5,5,5-heptafluoropentoxy)phenyl)aniline)] (PFO) or tungsten oxide (WO3); the hole transport layer thickness is 20-50 nm; it is prepared by spin coating or vacuum thermal evaporation, wherein the spin coating rotation speed is 2000-4000 rpm, the time is 20-60 s, the acceleration is 200-1000 rpm / s, and the annealing temperature is 50-60 ℃; the vacuum thermal evaporation deposition rate is 0.2-0.5 Å / s, preferably 0.3-0.45 Å / s;

[0021] The quantum dot luminescent layer material is cadmium-based electroluminescent quantum dots (CdSe / ZnS) or cadmium-free electroluminescent quantum dots (ZnSe / ZnS); the thickness of the quantum dot luminescent layer is 20-50 nm; it is prepared by spin coating, with a spin coating speed of 2000-4000 rpm, a spin coating time of 20-60 s, an acceleration of 200-1000 rpm / s, and an annealing temperature of 50-60 ℃;

[0022] The electron transport layer material is nano-zinc oxide or nano-zinc-oxymagnesium oxide; the electron transport layer thickness is 15-30 nm; it is prepared by spin coating; wherein the spin coating speed is 2500-4000 rpm, the time is 20-40 s, and the annealing temperature is 45-55 ℃.

[0023] The cathode layer material is aluminum, silver, or a low work function metal; the cathode layer thickness is 80-120 nm, preferably 90-100 nm; it is prepared by vacuum thermal evaporation, magnetron sputtering, or spin coating; for vacuum thermal evaporation and magnetron sputtering, the deposition rate is 0.5-5 Å / s, preferably 0.8-3 Å / s.

[0024] In step (4), the diameter of the obtained fiber quantum dot electroluminescent device is 200-800 μm; specifically, the obtained planar quantum dot electroluminescent device is rolled up with a glass plate, and the device is rolled up from one side to form a fiber-shaped quantum dot electroluminescent device.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] (1) The fiber quantum dot electroluminescent device prepared by this invention has a diameter as small as 200-800 μm, and can emit red, green, blue and their composite colors with high color purity and a brightness of up to 50,000 cd / m². 2 .

[0027] (2) The unique stacked structure of the device increases the radial distribution density of the polymer stress buffer layer, resulting in better stress dispersion and superior mechanical properties. In addition, the spirally distributed flexible substrate and buffer layer material wrap around the outside of the light-emitting functional layer, achieving a self-encapsulation effect, eliminating the need for additional encapsulation and providing good light-emitting stability.

[0028] (3) The planar device is processed into a fibrous device by push-roll forming, which not only retains the excellent photoelectric performance of the planar device, but also gives the device high flexibility. It is a universal process for preparing high-performance fiber flexible electronic devices. Attached Figure Description

[0029] Figure 1 This is a structural diagram of a fiber quantum dot electroluminescent device.

[0030] Figure 2 The image shows the illuminated red light device prepared in Example 1.

[0031] Figure 3 The graph shows the brightness of the red light device prepared in Example 1 as a function of voltage.

[0032] Figure 4 The spectrum of the red light device prepared in Example 1.

[0033] Figure 5 The image shows the illuminated green light device prepared in Example 2.

[0034] Figure 6 The graph shows the brightness of the green light device prepared in Example 2 as a function of voltage.

[0035] Figure 7 The spectrum of the green light device prepared in Example 2.

[0036] Figure 8 The image shows the illuminated blue light device fabricated in Example 3.

[0037] Figure 9 The graph shows the brightness of the blue light device prepared in Example 3 as a function of voltage.

[0038] Figure 10 The spectrum of the blue light device prepared in Example 3. Detailed Implementation

[0039] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments.

[0040] All reagents used in the following examples are commercially available, and all equipment is commercially available.

[0041] Example 1: Red fiber quantum dot electroluminescent device

[0042] Step 1: Preparation of the flexible polymer substrate

[0043] The PDMS matrix and crosslinking agent were mixed and stirred at a mass ratio of 9:1. The prepared solution was then spin-coated onto a PET sheet at a speed of 4000 rpm for 80 s with an acceleration of 500 rpm / s. The spin-coated film was then placed in a vacuum oven along with the PET sheet and cured at 60 ℃ for 1 h to obtain a flexible substrate.

[0044] Step 2: Preparation of the polymer stress buffer layer

[0045] The flexible substrate obtained in step 1 was subjected to oxygen treatment at a power of 100 W for 1 min. Then, 5% ammonium dichromate (based on the mass of PVA) was added to a 5% PVA aqueous solution, and the mixture was stirred for 5 min under light-protected conditions. The mixture was then spin-coated onto the flexible substrate at a speed of 2000 rpm for 30 s with an acceleration of 300 rpm / s to obtain a polymer stress buffer layer.

[0046] Step 3: Preparation of the metal oxide smoothing buffer layer and the anode layer

[0047] The designed anode mask is attached to the polymer stress buffer layer prepared in step 2, and then... -4 MoO3 was deposited as a smooth buffer layer of metal oxide at a rate of 0.3 Å / s under a vacuum of Pa, with a thickness of 10 nm. Then, Au was deposited as an anode layer at a rate of 0.3 Å / s, with a thickness of 20 nm.

[0048] Step 4: Preparation of the hole injection layer

[0049] The device with the smooth buffer layer and anode layer obtained in step 3 was subjected to oxygen treatment at a power of 150 W for 1 min. Then, a PEDOT:PSS solution was spin-coated on it at a speed of 2000 rpm for 20 s with an acceleration of 800 rpm / s. After spin-coating, it was annealed at 60 ℃ for 1 h to obtain the hole injection layer.

[0050] Step 5: Fabrication of the hole transport layer and the red quantum dot luminescent layer

[0051] In a glove box (argon atmosphere), TFB solution was spin-coated onto the hole injection layer prepared in step 4 at a rotation speed of 2000 rpm for 30 s with an acceleration of 1000 rpm / s. Then, it was annealed at 60 °C for 45 min to obtain the hole transport layer. Next, in the glove box, CdSe / ZnS red quantum dot solution was spin-coated onto the hole transport layer at a rotation speed of 2000 rpm for 30 s with an acceleration of 1000 rpm / s. After spin-coating, it was annealed at 50 °C for 30 min to obtain the red quantum dot luminescent layer.

[0052] Step 6: Fabrication of the electron transport layer

[0053] In a glove box, the nano zinc oxide solution was dynamically spin-coated onto the light-emitting layer prepared in step 5. After the rotation speed reached 3000 rpm, the solution was rapidly and continuously dropped onto the center of the device over a period of 40 s. After spin-coating, the device was annealed at 50 ℃ for 30 min to obtain the electron transport layer.

[0054] Step 7: Preparation of the cathode layer

[0055] The designed cathode mask is attached to the electron transport layer prepared in step 6, at a depth of 3×10⁻⁶. -4 Under a vacuum of Pa, Al was deposited as a cathode layer at a rate of 2.0 Å / s with a thickness of 100 nm using a vacuum thermal evaporation method, resulting in a planar electroluminescent device.

[0056] Step 8: Fabrication of Fiber Quantum Dot Electroluminescent Devices

[0057] The planar electroluminescent device obtained in step 7 is rolled up using a glass plate, starting from one side of the device to form a fibrous quantum dot electroluminescent device with a diameter of 200-500 μm.

[0058] In this device, the self-encapsulating characteristic allows it to emit light stably in an air environment (e.g., Figure 2 As shown in the figure, under standard test conditions, the device achieves a brightness exceeding 100,000 cd / m² at a DC operating voltage of 6 V. 2 (like Figure 3 As shown), and the emission peak wavelength of the spectral test is 632 nm, with a full width at half maximum (FWHM) of less than 30 nm (as shown). Figure 4 (As shown). This device combines excellent optoelectronic properties with flexible design, and has broad application prospects in the field of wearable flexible electronic devices.

[0059] Example 2: Green fiber quantum dot electroluminescent device

[0060] Step 1: Preparation of the flexible polymer substrate

[0061] The PI solution was spin-coated onto the PP sheet at a speed of 3000 rpm for 60 s with an acceleration of 500 rpm / s. The spin-coated film was then placed in a vacuum oven along with the PP sheet and cured at 60 ℃ for 2 h to obtain a flexible substrate.

[0062] Step 2: Preparation of the polymer stress buffer layer

[0063] The PP sheet with a flexible substrate obtained in step 1 is placed in the deposition chamber of CVD, and 1 g of Parylene is weighed into the evaporation chamber to obtain a polymer stress buffer layer by chemical vapor deposition.

[0064] Step 3: Preparation of the metal oxide smoothing buffer layer and the anode layer

[0065] The designed anode mask is attached to a PP sheet that has already been prepared with a flexible substrate and stress buffer layer, at a depth of 3×10. -4 MoO3 was deposited as a smooth buffer layer of metal oxide at a rate of 0.3 Å / s under a vacuum of Pa, with a thickness of 10 nm. Then, Au was deposited as an anode layer at a rate of 0.3 Å / s, with a thickness of 20 nm.

[0066] Step 4: Preparation of the hole injection layer

[0067] The anode layer prepared in step 3 was subjected to oxygen treatment at a power of 150 W for 1 min. Then, a PEDOT:PSS solution was spin-coated onto it at a speed of 2000 rpm for 20 s with an acceleration of 800 rpm / s. After spin-coating, the layer was annealed at 60 °C for 1 h to obtain the hole injection layer.

[0068] Step 5: Fabrication of the hole transport layer and the green quantum dot emitting layer

[0069] In a glove box (argon atmosphere), TFB solution was spin-coated onto the hole injection layer obtained in step 4 at a rotation speed of 2000 rpm for 30 s with an acceleration of 1000 rpm / s. After spin-coating, the layer was annealed at 60 °C for 45 min to obtain the hole transport layer. Then, CdSe / ZnS green quantum dot solution was spin-coated onto the hole transport layer in the glove box at a rotation speed of 2000 rpm for 30 s with an acceleration of 1000 rpm / s. After spin-coating, the layer was annealed at 50 °C for 30 min to obtain the green quantum dot luminescent layer.

[0070] Step 6: Fabrication of the electron transport layer

[0071] In a glove box, the nano zinc oxy magnesium solution was dynamically spin-coated onto the light-emitting layer prepared in step 5. After the rotation speed reached 3000 rpm, the solution was rapidly and continuously dropped onto the center of the device over a period of 30 s. After spin-coating, the device was annealed at 50 ℃ for 30 min to obtain the electron transport layer.

[0072] Step 7: Preparation of the cathode layer

[0073] The designed cathode mask is attached to the electron transport layer prepared in step 6, at a depth of 3×10⁻⁶. -4 Under a vacuum of Pa, Ag was deposited as a cathode layer at a rate of 1.0 Å / s with a thickness of 80 nm using vacuum thermal evaporation, resulting in a planar quantum dot electroluminescent device.

[0074] Step 8: Fabrication of Fiber Quantum Dot Electroluminescent Devices

[0075] The planar electroluminescent device obtained in step 7 is rolled up using a glass plate, starting from one side of the device to form a fibrous quantum dot electroluminescent device with a diameter of 400-600 μm.

[0076] In this device, the self-encapsulating characteristic allows it to emit light stably in an air environment (e.g., Figure 5 As shown in the figure, under standard test conditions, the device achieves a brightness exceeding 50,000 cd / m² at a DC operating voltage of 6 V. 2 (like Figure 6 As shown), and the emission peak wavelength of the spectral test is 532 nm, with a full width at half maximum (FWHM) of less than 30 nm (as shown). Figure 7 (As shown).

[0077] Example 3: Blue fiber quantum dot electroluminescent device

[0078] Step 1: Preparation of the flexible polymer substrate

[0079] SEBS and n-octane solution were prepared into a solution at a mass ratio of 1:5. After stirring at room temperature for 6 h, the solution was spin-coated onto PP sheet at a speed of 4000 rpm for 60 s with an acceleration of 500 rpm / s. The spin-coated film was then placed in a vacuum oven along with the PP sheet and cured at 60 ℃ for 4 h to obtain a polymer flexible substrate.

[0080] Step 2: Preparation of the polymer stress buffer layer

[0081] The PP sheet with a flexible polymer substrate obtained in step 1 is placed in the deposition chamber of a chemical vapor deposition (CVD) apparatus. 0.8 g of Parylene is weighed into the evaporation chamber, and a polymer stress buffer layer is obtained by CVD.

[0082] Step 3: Preparation of the metal oxide smoothing buffer layer and the anode layer

[0083] The designed anode mask is attached to the polymer stress buffer layer prepared in step 2, and then... -4 ITO with a thickness of 25 nm was deposited as the anode layer at a rate of 1 Å / s using a vacuum thermal evaporation method under a vacuum of Pa.

[0084] Step 4: Preparation of the hole injection layer

[0085] The anode layer obtained in step 3 was vacuum thermally deposited again with the same pattern at 3×10 -4 MoO3 was deposited as a hole injection layer with a thickness of 5 nm at a vacuum of 0.2 Å / s using a vacuum thermal evaporation method under a vacuum of Pa.

[0086] Step 5: Fabrication of the hole transport layer and the blue quantum dot emitting layer

[0087] The hole injection layer prepared in step 4 was subjected to oxygen treatment at a power of 100 W for 1 min. Then, in a glove box (argon atmosphere), TFB solution was spin-coated onto the hole injection layer at a rotation speed of 2000 rpm for 40 s with an acceleration of 500 rpm / s. The layer was then annealed at 60 °C for 45 min to obtain the hole transport layer. Next, in a glove box, CdSe / ZnS blue quantum dot solution was spin-coated onto the hole transport layer at a rotation speed of 2000 rpm for 40 s with an acceleration of 500 rpm / s. After spin-coating, the layer was annealed at 50 °C for 30 min to obtain the blue quantum dot luminescent layer.

[0088] Step 6: Fabrication of the electron transport layer

[0089] In a glove box, the nano zinc oxide solution was dynamically spin-coated onto the light-emitting layer prepared in step 5. After the rotation speed reached 3000 rpm, the solution was rapidly and continuously dropped onto the center of the device over a period of 20 s. After spin-coating, the device was annealed at 50 ℃ for 20 min to obtain the electron transport layer.

[0090] Step 7: Preparation of the cathode layer

[0091] The designed cathode mask is attached to the electron transport layer prepared in step 6, at a depth of 3×10⁻⁶. -4 Under a vacuum of Pa, Al was deposited as a cathode layer at a rate of 3.0 Å / s with a thickness of 100 nm using vacuum thermal evaporation, resulting in a planar quantum dot electroluminescent device.

[0092] Step 8: Fabrication of Fiber Quantum Dot Electroluminescent Devices

[0093] The planar quantum dot electroluminescent device obtained in step 7 is rolled up using a glass plate. The roll is formed starting from one side of the device to obtain a fibrous quantum dot electroluminescent device with a diameter of 500-800 μm.

[0094] In this device, the self-encapsulating characteristic allows it to emit light stably in an air environment (e.g., Figure 8 As shown in the figure, under standard test conditions, the device achieves a brightness exceeding 1000 cd / m² at a DC operating voltage of 6 V. 2 (like Figure 9 As shown), and the emission peak wavelength of the spectral test is 468 nm, with a full width at half maximum (FWHM) of less than 30 nm (as shown). Figure 10 (As shown).

[0095] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A fiber-shaped quantum dot electroluminescent device, characterized in that, The spiral structure is formed by rolling multiple layers of materials, which, from the outermost layer inward, consist of: a flexible polymer substrate; a stress buffer layer, including a polymer stress buffer layer and a metal oxide smooth buffer layer; and an anode layer of high work function material. Hole injection layer, used to reduce the potential barrier that holes need to overcome during transmission; Hole transport layer, used to optimize the efficiency of hole transmission to the emissive layer; Quantum dot light-emitting layer, where holes and electrons recombine to emit light; An electron transport layer is used to optimize the efficiency of electron transmission into the light-emitting layer while blocking further hole transport; a cathode layer made of low work function material.

2. The fiber quantum dot electroluminescent device according to claim 1, characterized in that: The polymer flexible substrate material is silicone rubber, ethylene-ethylene-butene-styrene block copolymer, or polyimide; the thickness of the polymer flexible substrate is 20-100 μm. The polymer stress buffer layer material is polyvinyl alcohol, polystyrene, or phenelzine; the thickness of the polymer stress buffer layer is 0.5-10 μm. The metal oxide smoothing buffer layer material is one of molybdenum oxide and zinc oxide; the thickness of the metal oxide smoothing buffer layer is 5-15 nm; The anode layer material is indium tin oxide, aluminum-doped zinc oxide, graphene, or a high work function metal, and the anode layer thickness is 10-30 nm. The cathode layer material is indium tin oxide, aluminum-doped zinc oxide, graphene, or a low work function metal, and the cathode layer thickness is 80-120 nm. The hole injection layer material is poly(3,4-ethylenedioxythiophene):polystyrene sulfonate, MoO3 or NiO; the hole injection layer thickness is 10-20 nm. The hole transport layer material is poly[(9,9-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine)] (TFB), poly[(9,9-dioctylfluorene-2,7-diyl)-alternating-(4,4'-(N-(4-(1,1,1,3,5,5,5-heptafluoropentoxy)phenyl)aniline)] (PFO), or tungsten oxide (WO3); the hole transport layer thickness is 20-50 nm. The quantum dot luminescent layer material is cadmium-based electroluminescent quantum dots (CdSe / ZnS) or cadmium-free electroluminescent quantum dots (ZnSe / ZnS); the thickness of the quantum dot luminescent layer is 20-50 nm. The electron transport layer material is nano-zinc oxide or nano-zinc-oxygen magnesium; the electron transport layer thickness is 15-30 nm.

3. The method for fabricating the fibrous quantum dot electroluminescent device as described in claim 1 or 2, characterized in that, The specific steps are as follows: (1) A flexible polymer substrate was prepared on a sheet material by spin coating; (2) A polymer stress buffer layer and a metal oxide smoothing buffer layer are sequentially prepared on a flexible substrate; (3) The anode layer, hole injection layer, hole transport layer, quantum dot light-emitting layer, electron transport layer and cathode layer of the quantum dot light-emitting device are sequentially prepared on the metal oxide smooth buffer layer; (4) The obtained planar quantum dot light-emitting device is rolled into shape by a film rolling process to obtain a spiral fiber quantum dot electroluminescent device.

4. The preparation method according to claim 3, characterized in that, The sheet material mentioned in step (1) is polyethylene terephthalate, polypropylene or silicon wafer; the spin coating speed is 1000-5000 rpm, the time is 40-120 s, and the acceleration is 100-1000 rpm / s.

5. The preparation method according to claim 3, characterized in that, In step (2): The polymer stress buffer layer is prepared on a flexible substrate by spin coating or chemical vapor deposition; wherein the spin coating speed is 2000-4000 rpm, the time is 20-60 s, and the acceleration is 200-800 rpm / s; the mass of the CVD material is 0.5-1.5 g. The metal oxide smooth buffer layer is prepared by vacuum thermal evaporation or magnetron sputtering.

6. The preparation method according to claim 3, characterized in that, In step (3): The anode layer is prepared by vacuum thermal evaporation, magnetron sputtering, or spin coating. The hole injection layer is prepared by spin coating: the spin coating speed is 2000-4000 rpm, the time is 20-60 s, the acceleration is 200-800 rpm / s, and the annealing temperature is 50-60 ℃; or it is prepared by vacuum thermal evaporation, with a deposition rate of 0.2-0.5 Å / s. The hole transport layer is prepared by spin coating or vacuum thermal evaporation, wherein the spin coating rotation speed is 2000-4000 rpm, the time is 20-60 s, the acceleration is 200-1000 rpm / s, and the annealing temperature is 50-60 ℃; the vacuum thermal evaporation deposition rate is 0.2-0.5 Å / s. The quantum dot luminescent layer was prepared by spin coating, with a spin coating speed of 2000-4000 rpm, a spin coating time of 20-60 s, an acceleration of 200-1000 rpm / s, and an annealing temperature of 50-60 ℃. The electron transport layer is prepared by spin coating or vacuum thermal evaporation. The spin coating is performed at a rotation speed of 2000-4000 rpm for 20-60 s, with an acceleration of 200-1000 rpm / s and an annealing temperature of 50-60 ℃. The vacuum thermal evaporation deposition rate is 0.2-0.5 Å / s. The cathode layer is prepared by vacuum thermal evaporation and magnetron sputtering; the deposition rate of vacuum thermal evaporation and magnetron sputtering is 0.5-5 Å / s.

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