Luminescent fiber and preparation method thereof

Abstract

The invention discloses a preparation method of a luminescent fiber and the luminescent fiber. The preparation method comprises the following steps: immersing a fiber core wire into first slurry, taking out the fiber core wire, and performing first annealing to form an electron injection layer outside the fiber core wire; immersing the fiber core wire into the second slurry, taking out the fiber core wire, and performing secondary annealing to form a light-emitting layer outside the electron injection layer; immersing the fiber core wire into third slurry, taking out the fiber core wire, and performing third annealing to form a hole injection layer outside the light-emitting layer; a surface layer is formed outside the hole injection layer, the fiber core wire is a first electrode, and the surface layer is a second electrode.

Description

Preparation method of luminescent fibers, luminescent fibers Technical Field

[0001] This invention relates to the field of luminescent materials technology, and more specifically, to a method for preparing luminescent fibers and luminescent fibers themselves. Background Technology

[0002] In related technologies, luminescent fibers typically consist of a core electrode surrounded by an electroluminescent material and a shell electrode surrounding the electroluminescent material. A voltage is applied between the core electrode and the shell electrode to cause the electroluminescent material to emit light. In the preparation of luminescent fibers, a thermoplastic elastomer and an electroluminescent active material are first physically blended in a melt-coating apparatus, then melt-coated onto conductive fibers. After online cooling and curing, conductive fibers coated with an electroluminescent active layer are obtained. The melt-coating method is complex and not conducive to mass production.

[0003] Therefore, a new technical solution is needed to solve the above-mentioned technical problems. Summary of the Invention

[0004] One object of the present invention is to provide a new technical solution for the preparation method of luminescent fibers.

[0005] According to a first aspect of the present invention, a method for preparing luminescent fibers is provided. The method includes:

[0006] The fiber core is immersed in the first slurry, and after being removed, it undergoes a first annealing to form an electron injection layer on the outside of the fiber core.

[0007] The fiber core is immersed in the second slurry, and after being removed, it is annealed a second time to form a light-emitting layer outside the electron injection layer;

[0008] The fiber core is immersed in the third slurry, and after being removed, it is annealed for the third time to form a hole injection layer outside the light-emitting layer;

[0009] A surface layer is formed outside the hole injection layer, wherein the fiber core wire is a first electrode and the surface layer is a second electrode.

[0010] Optionally, the first slurry includes a first active substance and a first solvent. The first active substance includes at least one of ZnO, Ca, Mg / Ag alloy, Ba / Al alloy, SiO2, and LiF. The first solvent includes at least one of isopropanol, acetone, ethanol, and deionized water.

[0011] Optionally, the temperature of the first annealing is 80℃-90℃, and the annealing time is 10 minutes-20 minutes.

[0012] Optionally, the second slurry includes a second active substance and a second solvent, wherein the second active substance includes at least one of PPV, titanium dioxide, and chromium sulfide; and the second solvent includes an organic aromatic hydrocarbon.

[0013] Optionally, the temperature of the second annealing is 100℃-110℃, and the annealing time is 8 minutes-20 minutes.

[0014] Optionally, the third slurry includes a third active substance and a third solvent, wherein the third active substance includes at least one of PEDOT, PSS, polyaniline, and polypyrrole; and the third solvent includes at least one of deionized water and ethanol.

[0015] Optionally, the temperature of the third annealing is 100℃-110℃, and the annealing time is 8 minutes-20 minutes.

[0016] Optionally, at least one of the electron injection layer, the light-emitting layer, and the hole injection layer is a multilayer structure.

[0017] Optionally, the surface layer is an organic fiber material coated with a metal layer.

[0018] Optionally, after the step of forming a surface layer outside the hole injection layer, the method further includes:

[0019] An encapsulation layer is formed on the outside of the surface layer.

[0020] Optionally, the fiber core is sequentially immersed in the first slurry, the second slurry, and the third slurry, and the moving speed of the fiber core is 3 m / min to 10 m / min.

[0021] According to a second aspect of the present invention, a luminescent fiber is provided. This luminescent fiber is prepared by the method for preparing luminescent fibers according to the present invention.

[0022] In this embodiment of the invention, the electron injection layer, the light-emitting layer, and the hole injection layer are formed sequentially by continuous dip coating and annealing. This process is simple and easy to operate. Furthermore, compared to deposition, the dip coating method produces a more uniform thickness for each part of the electron injection layer, the light-emitting layer, and the hole injection layer.

[0023] Furthermore, in this embodiment of the invention, the preparation method of the present invention can form an inverted structure, namely, radially arranged from the inside out, consisting of a fiber core, an electron injection layer, a light-emitting layer, a hole injection layer, and a surface layer. The light-emitting layer is an organic light-emitting diode. The hole injection layer is an organic polymer. Both the light-emitting layer and the hole injection layer are organic material layers. The two organic material layers can effectively coat the electron injection layer, preventing the electron injection layer from contacting water and oxygen, thereby effectively reducing the risk of oxidation of the electron injection layer and improving the service life and brightness of the light-emitting fiber.

[0024] Furthermore, the hole injection layer in this embodiment of the invention is an organic polymer, which absorbs less light and has better light transmission than the electron injection layer. This allows the light emitted by the light-emitting layer to be emitted more effectively, thereby improving the brightness and contrast of the light-emitting fiber, making the light-emitting effect of the light-emitting fiber more vivid and enhancing the visual experience.

[0025] Other features and advantages of the invention will become clear from the following detailed description of exemplary embodiments of the invention with reference to the accompanying drawings. Attached Figure Description

[0026] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the invention and, together with their description, serve to explain the principles of the invention.

[0027] Figure 1 is a flowchart of a method for preparing luminescent fibers according to an embodiment of the present invention.

[0028] Figure 2 is a schematic diagram of the structure of the luminescent fiber according to an embodiment of the present invention.

[0029] Figure 3 is a curve showing the change in brightness of the luminescent fiber with voltage according to an embodiment of the present invention.

[0030] Explanation of reference numerals in the attached figures:

[0031] 101. Fiber core wire; 102. Electron injection layer; 103. Light-emitting layer; 104. Hole injection layer; 105. Surface layer; 106. Encapsulation layer. Detailed Implementation

[0032] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention.

[0033] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0034] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0035] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0036] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0037] According to an embodiment of the present invention, a method for preparing luminescent fibers is provided. As shown in FIG1, the preparation method includes:

[0038] S1. Immerse the fiber core 101 in the first slurry, take it out and perform the first annealing to form an electron injection layer 102 on the outside of the fiber core 101.

[0039] S2. Immerse the fiber core 101 in the second slurry, remove it and perform a second annealing to form a light-emitting layer 103 outside the electron injection layer 102.

[0040] S3. Immerse the fiber core 101 in the third slurry, remove it and perform a third annealing to form a hole injection layer 104 outside the light-emitting layer 103.

[0041] S4. A surface layer 105 is formed outside the hole injection layer 104, wherein the fiber core wire 101 is the first electrode and the surface layer 105 is the second electrode.

[0042] Specifically, the fiber core 101 serves as the substrate of the luminescent fiber. The fiber core 101 is conductive. It connects to an external circuit and acts as the cathode of the luminescent fiber, providing electrons. The material of the fiber core 101 includes at least one of metal, conductive ceramic, conductive glass, and conductive organic materials. The diameter of the fiber core 101 is 0.01mm-0.6mm. If the diameter of the fiber core 101 is too thin, its tensile strength is low, making it prone to breakage; conversely, if the diameter is too thick, the flexibility of the luminescent fiber is poor. A diameter within the above range provides both high tensile strength and good flexibility.

[0043] In this embodiment, the fiber core 101 is a roll. In step S1, during preparation, the ends of the fiber core 101 are pulled out and immersed in a first slurry. Then, the ends of the fiber core 101 are pulled out of the first slurry and subjected to a first annealing. After the first annealing, an electron injection layer 102 is formed around the fiber core 101. It should be noted that the first slurry contains a low work function material, typically a metal or an inorganic non-metallic material. The first annealing is performed in an oven. The oven temperature is adjusted to a set temperature. The first slurry is heated at this temperature and then naturally cooled at room temperature. For example, room temperature refers to 20°C-30°C. At this temperature, cracking of the electron injection layer 102 due to excessively rapid cooling can be avoided.

[0044] In step S2, the end of the fiber core 101 continues to enter the second slurry. Then, the end of the fiber core 101 is extracted from the second slurry and subjected to a second annealing. After the second annealing, a light-emitting layer 103 is formed around the fiber core 101. It should be noted that the first slurry contains electroluminescent materials, typically organic materials. The second annealing is performed in an oven. The oven temperature is adjusted to a set temperature. The second slurry is heated at this temperature and then naturally cooled at room temperature. For example, room temperature refers to 20℃-30℃. This temperature prevents cracking of the light-emitting layer 103 due to excessively rapid cooling.

[0045] In step S3, the end of the fiber core 101 continues to enter the third slurry. Then, the end of the fiber core 101 is extracted from the third slurry and subjected to a third annealing. After the third annealing, a cavity injection layer 104 is formed around the fiber core 101. It should be noted that the third slurry contains a material with cavity transport capabilities, typically an organic material. The third annealing is performed in an oven. The oven temperature is adjusted to a set temperature. The third slurry is heated at this temperature and then naturally cooled at room temperature. For example, room temperature refers to 20℃-30℃. At this temperature, cracking of the cavity injection layer 104 due to excessively rapid cooling can be avoided.

[0046] In step S4, the surface layer 105 covers the hole injection layer 104. The surface layer 105 is conductive. The material of the surface layer 105 includes metal, conductive ceramic, conductive glass, conductive organic materials, etc. The surface layer 105 is formed by electroplating, chemical plating, spraying, dip coating, etc., or by weaving conductive fibers.

[0047] In existing technologies, the electron injection layer 102 is formed by deposition methods, such as physical vapor deposition (PVD) and chemical vapor deposition (CVD). These methods require relatively high temperatures, such as 150°C to 200°C. This results in a long subsequent cooling time and increases the risk of cracking in the electron injection layer 102 during cooling. In this embodiment of the invention, the electron injection layer 102, the light-emitting layer 103, and the hole injection layer 104 are formed sequentially by dip coating and annealing. This process is simple and easy to operate. Furthermore, compared to deposition, dip coating results in more uniform thicknesses in each portion of the electron injection layer 102, the light-emitting layer 103, and the hole injection layer 104.

[0048] Furthermore, in existing technologies, luminescent fibers typically include a fiber core 101, a hole injection layer 104, a light-emitting layer 103, an electron injection layer 102, and a surface layer 105 radially from the inside out. Typically, the electron injection layer 102 is a metal or inorganic non-metallic material. These materials are sensitive to water and oxygen and are prone to oxidation during use, leading to a decrease in the brightness and lifespan of the luminescent fiber. In this embodiment of the invention, the preparation method of the present invention can form an inverted structure, namely, a fiber core 101, an electron injection layer 102, a light-emitting layer 103, a hole injection layer 104, and a surface layer 105 radially from the inside out. The light-emitting layer 103 is an organic light-emitting diode. The hole injection layer 104 is an organic polymer. Both the light-emitting layer 103 and the hole injection layer 104 are organic material layers. The two organic material layers effectively coat the electron injection layer 102, preventing the electron injection layer 102 from contacting water and oxygen, thereby effectively reducing the risk of oxidation of the electron injection layer 102 and improving the lifespan and brightness of the luminescent fiber.

[0049] Furthermore, the hole injection layer 104 in this embodiment of the invention is an organic polymer, which absorbs less light and has better light transmission than the electron injection layer 102. This allows the light emitted by the light-emitting layer 103 to be emitted more effectively, thereby improving the brightness and contrast of the light-emitting fiber, making the light-emitting effect of the light-emitting fiber more vivid and enhancing the visual experience.

[0050] In one embodiment of the present invention, the first slurry includes a first active substance and a first solvent. The first active substance includes at least one of ZnO, Ca, Mg / Ag alloy, Ba / Al alloy, SiO2, and LiF. The first solvent includes at least one of isopropanol, acetone, ethanol, and deionized water.

[0051] In this embodiment, the first active material is the aforementioned low work function chemical reaction material. Optionally, the first active material can be any one or a mixture of more than one of ZnO, Ca, Mg / Ag alloy, Ba / Al alloy, SiO2, and LiF. When preparing the first slurry, the first active material is added to the first solvent and mixed using a cell disruptor for a set time, for example, 20-40 minutes. Optionally, the first solvent is any one or a mixture of isopropanol, acetone, ethanol, and deionized water. In the first slurry, the mass percentage of the first active material is 2%-10%. If the content of the first active material in the first slurry is too low, the thickness of the electron injection layer 102 will be too small, requiring multiple dip-coatings and complicating the preparation process; conversely, if the content of the first active material is too high, it will easily lead to uneven thickness of the electron injection layer 102 at different locations on the fiber core 101. Maintaining the mass percentage of the first active material within the above range avoids both excessively small thickness of the electron injection layer 102 and uneven thickness of the electron injection layer 102.

[0052] Optionally, during the dip coating process, the moving speed of the fiber core 101 is 3 mm / min to 10 mm / min. If the moving speed of the fiber core 101 is too low, the production efficiency will be low; conversely, if the moving speed of the fiber core 101 is too high, the dip coating speed will not be able to meet the speed of the first annealing. A moving speed of the fiber core 101 within the above range ensures both high production efficiency and that the dip coating speed matches the speed of the first annealing.

[0053] In one embodiment of the present invention, the temperature of the first annealing is 80°C-90°C, and the annealing time is 10-20 minutes.

[0054] If the first annealing temperature is too low or the time is too short, the crystal quality of the electron-injected layer 102 is likely to be poor. Conversely, if the first annealing temperature is too high or the time is too long, the grain size of the electron-injected layer 102 is likely to be too large, the surface is rough, and stress concentration is likely to occur. In this embodiment, the first annealing temperature is 80℃-90℃, and the annealing time is 10 minutes-20 minutes. Within this range, both the high crystal quality of the electron-injected layer 102 and the excessively large grain size of the electron-injected layer 102 are ensured, and stress concentration is less likely to occur in the electron-injected layer 102.

[0055] Optionally, the temperature of the first annealing is 80℃, 82℃, 84℃, 86℃, 88℃, 90℃, etc., and the annealing time is 10 minutes, 12 minutes, 14 minutes, 16 minutes, 18 minutes, 19 minutes, 20 minutes, etc. The above values ​​can ensure the high crystal quality of the electron injection layer 102, and avoid the excessive grain size of the electron injection layer 102, so that the electron injection layer 102 is not prone to stress concentration.

[0056] In one embodiment of the present invention, the second slurry includes a second active substance and a second solvent, wherein the second active substance includes at least one of PPV, titanium dioxide, and chromium sulfide; and the second solvent includes an organic aromatic hydrocarbon.

[0057] In this embodiment, the second active material includes any one or a mixture of PPV, titanium dioxide, and chromium sulfide. When preparing the second slurry, the second active material is added to the second solvent and stirred, for example, for 10-30 minutes. Optionally, the second solvent is any one or a mixture of benzene, toluene, and ethylbenzene. The mass percentage of the second active material is 1%-8%. If the content of the second active material in the second slurry is too low, the thickness of the light-emitting layer 103 will be too small, requiring multiple dip-coatings and complicating the preparation process; conversely, if the content of the second active material is too high, it will easily lead to uneven thickness of the light-emitting layer 103 at different locations on the fiber core 101. The mass percentage of the second active material within the above range can avoid both excessively thin and uneven thickness of the light-emitting layer 103.

[0058] Optionally, during the dip coating process, the moving speed of the fiber core 101 is 3 mm / min to 10 mm / min. If the moving speed of the fiber core 101 is too low, the production efficiency will be low; conversely, if the moving speed of the fiber core 101 is too high, the dip coating speed will not be able to meet the speed of the second annealing. A moving speed of the fiber core 101 within the above range ensures both high production efficiency and a match between the dip coating speed and the speed of the second annealing.

[0059] In one embodiment of the present invention, the temperature of the second annealing is 100°C-110°C, and the annealing time is 8 minutes-20 minutes.

[0060] If the second annealing temperature is too low or the time is too short, the microstructure of the light-emitting layer 103 cannot be effectively improved, and a good luminescence effect cannot be achieved. Conversely, if the second annealing temperature is too high or the time is too long, the light-emitting layer 103 is prone to decomposition, resulting in a decrease in the luminescence performance of the light-emitting layer 103. In this embodiment, the second annealing temperature is 100℃-110℃, and the annealing time is 8 minutes-20 minutes. Within this range, the microstructure of the light-emitting layer 103 can be effectively improved while avoiding its decomposition, resulting in good luminescence performance of the light-emitting layer 103.

[0061] Optionally, the temperature of the first annealing is 100℃, 102℃, 104℃, 106℃, 108℃, 110℃, etc., and the annealing time is 8 minutes, 10 minutes, 12 minutes, 14 minutes, 16 minutes, 18 minutes, 19 minutes, 20 minutes, etc. The above values ​​can effectively improve the microstructure of the light-emitting layer 103 and avoid the decomposition of the light-emitting layer 103, resulting in good light-emitting performance of the light-emitting layer 103.

[0062] In one embodiment of the present invention, the third slurry includes a third active substance and a third solvent, wherein the third active substance includes at least one of PEDOT, PSS, polyaniline, and polypyrrole; and the third solvent includes at least one of deionized water and ethanol.

[0063] In this embodiment, the third active material includes any one or a mixture of PEDOT, PSS, polyaniline, and polypyrrole. When preparing the third slurry, the third active material is added to the third solvent and stirred to ensure uniform mixing. Optionally, the third solvent is any one or a mixture of water and ethanol. The mass percentage of the third active material is 1%-10%. If the content of the third active material in the third slurry is too low, the thickness of the hole injection layer 104 will be too small, requiring multiple dip coatings and complicating the preparation process; conversely, if the content of the third active material is too high, it will easily lead to uneven thickness of the hole injection layer 104 at different locations on the fiber core 101. Maintaining the mass percentage of the third active material within the above range avoids both excessively thin and uneven thickness of the hole injection layer 104.

[0064] Optionally, during the dip coating process, the moving speed of the fiber core 101 is 3 mm / min to 10 mm / min. If the moving speed of the fiber core 101 is too low, the production efficiency will be low; conversely, if the moving speed of the fiber core 101 is too high, the dip coating speed will not be able to meet the speed of the third annealing. A moving speed of the fiber core 101 within the above range ensures both high production efficiency and matches the dip coating speed with the speed of the third annealing.

[0065] In one embodiment of the present invention, the temperature of the second annealing is 100°C-110°C, and the annealing time is 8 minutes-20 minutes.

[0066] If the temperature and time of the third annealing are too low, the microstructure of the hole injection layer 104 cannot be effectively improved, and a good hole transport effect cannot be achieved. Conversely, if the temperature and time of the third annealing are too high, the hole injection layer 104 is prone to decomposition, resulting in a decrease in the hole injection performance of the hole injection layer 104. In this embodiment, the temperature of the third annealing is 100℃-110℃, and the annealing time is 8 minutes-20 minutes. Within this range, the microstructure of the hole injection layer 104 can be effectively improved while avoiding its decomposition, resulting in good hole transport performance of the hole injection layer 104.

[0067] Optionally, the temperature of the first annealing is 100℃, 102℃, 104℃, 106℃, 108℃, 110℃, etc., and the annealing time is 8 minutes, 10 minutes, 12 minutes, 14 minutes, 16 minutes, 18 minutes, 19 minutes, 20 minutes, etc. The above values ​​can effectively improve the microstructure of the hole injection layer 104 and avoid the decomposition of the hole injection layer 104, resulting in good hole transmission performance of the hole injection layer 104.

[0068] In one embodiment of the present invention, at least one of the electron injection layer 102, the light-emitting layer 103 and the hole injection layer 104 is a multilayer structure.

[0069] The multilayer electron injection layer 102 can reduce the energy barrier of electron injection, enhance the stability of electrons during transmission, and reduce electron loss during transmission, thereby improving the overall performance of the luminescent fiber.

[0070] The multi-layer light-emitting layer 103 can achieve higher brightness and richer colors by stacking light-emitting layers 103 of different colors or different luminous efficiencies. For example, by stacking red, green and blue three-primary-color light-emitting layers 103, the light-emitting fibers can present different colors.

[0071] The multilayer hole injection layer 104 can reduce the energy barrier of hole injection, improve the hole injection efficiency, and increase the recombination probability of holes and electrons in the light-emitting layer 103, thereby improving the luminous efficiency.

[0072] The number of layers in a multi-layer structure can be 2, 3, 4, 5, 6, etc. Those skilled in the art can configure it according to actual needs.

[0073] In one embodiment of the present invention, the surface layer 105 is an organic fiber material coated with a metal layer.

[0074] In this embodiment, the surface layer 105 comprises an organic fiber material and a metal layer. The organic fiber material includes nylon, polyester, acrylic, polypropylene, etc. The metal layer comprises gold, silver, copper, aluminum, nickel, etc. The metal layer is deposited on the surface of the organic fiber material through methods such as vapor deposition, electroplating, or chemical plating. The surface layer 105 exhibits good durability and electrical conductivity. During preparation, the organic fiber material coated with the metal layer is woven and formed outside the hole injection layer 104 to form the surface layer 105.

[0075] In one embodiment of the present invention, after the step of forming a surface layer 105 outside the hole injection layer 104, the method further includes:

[0076] An encapsulation layer 106 is formed outside the surface layer 105.

[0077] In this embodiment, the encapsulation layer 106 effectively encapsulates the electron injection layer 102, the light-emitting layer 103, and the hole injection layer 104 to prevent water and oxygen from directly contacting these layers and causing oxidation. During encapsulation, a fiber core 101, covering the electron injection layer 102, the light-emitting layer 103, the hole injection layer 104, and the surface layer 105, is placed in a mold. For example, the mold is a tube mold, with the fiber core located at the core of the mold. Then, adhesive is injected into the tube. After the adhesive cures, the encapsulation layer 106 is formed.

[0078] In one embodiment of the present invention, the fiber core 101 is sequentially immersed in the first slurry, the second slurry, and the third slurry, and the moving speed of the fiber core 101 is 3 m / min to 10 m / min.

[0079] In this example, the fiber core 101 is continuously produced on the production line that forms the electron injection layer 102, the light-emitting layer 103, and the hole injection layer 104. The moving speed of the fiber core 101 is within the aforementioned range, which ensures both high production efficiency and matches the coating speed of the three materials with the speed of the three annealing processes, thereby enabling continuous production of the light-emitting fiber.

[0080] According to a second embodiment of the present invention, a luminescent fiber is provided. As shown in FIG2, the luminescent fiber is prepared by the method for preparing luminescent fibers according to the present invention.

[0081] Specifically, as shown in Figure 1, the luminescent fiber includes:

[0082] Fiber core wire 101, wherein the fiber core wire 101 is the first electrode;

[0083] An electron injection layer 102 is disposed around the core wire;

[0084] A light-emitting layer 103 is disposed around the electron injection layer 102;

[0085] Hole injection layer 104, the hole injection layer 104 being disposed around the light-emitting layer 103; and

[0086] Surface layer 105, which is disposed around the hole injection layer 104, is a second electrode.

[0087] The fiber core 101 serves as the substrate of the luminescent fiber. The fiber core 101 is conductive. It connects to an external circuit and acts as the cathode of the luminescent fiber, providing electrons. The fiber core 101 is made of at least one of metal, conductive ceramic, conductive glass, and conductive organic materials. The diameter of the fiber core 101 is 0.01mm-0.6mm. If the diameter of the fiber core 101 is too thin, its tensile strength is low, making it prone to breakage; conversely, if the diameter is too thick, the luminescent fiber will have poor flexibility. A diameter within the above range provides both high tensile strength and flexibility.

[0088] An electron injection layer 102 is disposed around the fiber core 101 and covers the outside of the fiber core 101. The electron injection layer 102 is used to regulate the movement and distribution of electrons. Under the action of an applied voltage, the electron injection layer 102 is used to effectively inject electrons from the cathode to the light-emitting layer 103. The electron injection layer 102 is a low work function material for chemical reactions, typically a metal or an inorganic non-metallic material.

[0089] The light-emitting layer 103 is disposed around the electron injection layer 102 and covers the electron injection layer 102. The light-emitting layer 103 is an organic light-emitting diode. In the light-emitting layer 103, electrons from the electron injection layer 102 and holes from the hole injection layer 104 meet and recombine to form excitons. The excitons release photons through radiative transitions, thereby emitting light.

[0090] A hole injection layer 104 is disposed around the light-emitting layer 103 and covers the outside of the light-emitting layer 103. The hole injection layer 104 is used to regulate the movement and distribution of holes. Under the action of an applied voltage, the hole injection layer 104 is used to effectively inject holes from the anode into the light-emitting layer 103. The hole injection layer 104 is an organic polymer.

[0091] The surface layer 105 is disposed around the hole injection layer 104 and covers the outside of the hole injection layer 104. The surface layer 105 is connected to an external circuit and serves as a second electrode, i.e., an anode. The surface layer 105 may be made of materials such as metal, conductive ceramic, conductive glass, or conductive organic materials.

[0092] In the prior art, a light-emitting fiber typically includes a fiber core 101, a hole injection layer 104, a light-emitting layer 103, an electron injection layer 102, and a surface layer 105 radially from the inside to the outside. Typically, the electron injection layer 102 is made of a metal or an inorganic non-metallic material. These materials are sensitive to water and oxygen and are prone to oxidation during use, leading to a decrease in the brightness and lifespan of the light-emitting fiber.

[0093] In this embodiment of the invention, the functional layers of the luminescent fiber are arranged in an inverted manner, that is, radially from the inside out, they are fiber core 101, electron injection layer 102, luminescent layer 103, hole injection layer 104, and surface layer 105. The luminescent layer 103 is an organic light-emitting diode (OLED). The hole injection layer 104 is an organic polymer. Both the luminescent layer 103 and the hole injection layer 104 are organic material layers. These two organic material layers effectively coat the electron injection layer 102, preventing it from contacting water and oxygen, thereby effectively reducing the risk of oxidation of the electron injection layer 102 and improving the lifespan and brightness of the luminescent fiber.

[0094] The hole injection layer 104 is an organic polymer, which absorbs less light and has better light transmission than the electron injection layer 102. This allows the light energy emitted by the light-emitting layer 103 to be emitted more effectively, thereby improving the brightness and contrast of the light-emitting fiber, making the light-emitting fiber more vibrant and enhancing the visual experience.

[0095] In one embodiment of the present invention, the first electrode is a cathode and the second electrode is an anode.

[0096] As previously described, the fiber core 101 serves as the cathode, providing electrons, which are then injected into the light-emitting layer 103 via the electron injection layer 102. The surface layer 105 serves as the anode, providing holes (positive charges), which are then injected into the light-emitting layer 103 via the hole injection layer 104. This arrangement enables the light-emitting fiber to emit light.

[0097] In one embodiment of the present invention, the electron injection layer 102 includes at least one of ZnO, Ca, Mg / Ag alloy, Ba / Al alloy, SiO2, and LiF.

[0098] In this embodiment, the electron injection layer 102 is made of any one or a mixture of ZnO, Ca, Mg / Ag alloy, Ba / Al alloy, SiO2, and LiF. For example, the electron injection layer 102 is coated onto the surface of the fiber core layer using processes such as vapor deposition or dip coating. All of the above materials are low work function materials, and electrons on their surfaces are more easily excited when subjected to an electric field, resulting in electron emission and thus low energy consumption of the luminescent fiber. Furthermore, the above materials have good chemical stability, making the luminescent fiber durable.

[0099] In one embodiment of the present invention, the hole injection layer 104 includes at least one of PEDOT, PSS, polyaniline, and polypyrrole.

[0100] In this embodiment, the hole injection layer 104 is made of any one or a mixture of PEDOT, PSS, polyaniline, and polypyrrole. For example, the hole injection layer 104 is coated onto the surface of the light-emitting layer 103 using processes such as vapor deposition or dip coating. These materials have the characteristics of high hole migration efficiency and good chemical stability, resulting in low energy consumption and good durability of the light-emitting fiber. Furthermore, the good light transmittance of these materials leads to higher brightness in the light-emitting zone.

[0101] In one embodiment of the present invention, the light-emitting layer 103 includes at least one of PPV, titanium dioxide, and chromium sulfide.

[0102] In this embodiment, the light-emitting layer 103 comprises any one or a mixture of multiple of PPV, titanium dioxide, and chromium sulfide, and is coated onto the surface of the electron injection layer 102 using processes such as vapor deposition or dip coating. The aforementioned materials exhibit low energy consumption, high luminous efficiency, and good chemical stability.

[0103] In one embodiment of the present invention, the thickness of the electron injection layer 102 is 10nm-80nm, the thickness of the hole injection layer 104 is 100nm-800nm, and the thickness of the light-emitting layer 103 is 20nm-150nm.

[0104] In this embodiment, an excessively thick electron injection layer 102 leads to low electron transport efficiency and high power consumption of the light-emitting fiber; conversely, an excessively thin electron injection layer 102 cannot prevent the cathode current from flowing directly to the anode. In this embodiment, the thickness of the electron injection layer 102 is 10nm-80nm. This thickness range allows the electron injection layer 102 to achieve both low power consumption and prevent the cathode current from flowing directly to the anode and recombinating with holes in the light-emitting layer 103. Optionally, the thickness of the electron injection layer 102 can be 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, etc., all of which allow the electron injection layer 102 to achieve both low power consumption and prevent the cathode current from flowing directly to the anode and recombinating with holes in the light-emitting layer 103.

[0105] Excessive thickness of the hole injection layer 104 leads to low hole transport efficiency and high power consumption of the light-emitting fiber; conversely, insufficient thickness of the hole injection layer 104 fails to prevent the cathode current from flowing directly to the anode. In this embodiment, the thickness of the hole injection layer 104 is 100nm-800nm. This thickness range allows the hole injection layer 104 to achieve both low power consumption and prevent the cathode current from flowing directly to the anode and recombination with the hole in the light-emitting layer 103. Optionally, the thickness of the hole injection layer 104 can be 100nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, or 800nm. These thickness values ​​all allow the hole injection layer 104 to achieve both low power consumption and prevent the cathode current from flowing directly to the anode and recombination with the hole in the light-emitting layer 103.

[0106] During recombination, holes and electrons require sufficient space to release energy and generate photons. If the thickness of the light-emitting layer 103 is too small, it cannot adequately absorb electrons and holes, thus reducing luminous efficiency. Furthermore, a thinner layer results in a shorter lifespan and easier aging. Conversely, a thicker layer leads to a higher driving voltage and lower energy efficiency for the light-emitting fiber. In this embodiment, the thickness of the light-emitting layer 103 is 20nm-150nm. Within this range, the light-emitting layer 103 provides sufficient space for recombination, resulting in a lower driving voltage, longer lifespan, and better durability for the light-emitting fiber. Optionally, the thickness of the light-emitting layer 103 can be 20nm, 30nm, 50nm, 70nm, 80nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, etc. These values ​​ensure that the light-emitting layer 103 provides sufficient space for the recombination of holes and electrons, and also result in a lower driving voltage for the light-emitting fiber, a longer lifespan for the light-emitting fiber, and good durability.

[0107] In one embodiment of the present invention, the fiber core 101 is made of at least one of metal, conductive ceramic, conductive glass, and conductive organic material.

[0108] In this embodiment, the fiber core 101 can be selected from any one or a mixture of several of the following: metal, conductive ceramic, conductive glass, and conductive organic material. Metals include, for example, copper, aluminum, gold, silver, stainless steel, and nickel. Conductive ceramics include, for example, TiO2, Nb2O5, WO3, Cr2O3, MnO, CoO, NiO, SiC, PbTe, or Co3O4. Conductive glass is formed on the glass surface through methods such as vapor deposition or spraying. Conductive organic materials include polythiophene, polyacetylene, etc., or a conductive layer is formed on the surface of an organic material. All of the above materials are conductive, flexible, have high tensile strength, and are durable.

[0109] In one embodiment of the present invention, the surface layer 105 is an organic fiber material coated with a metal layer.

[0110] In this embodiment, the surface layer 105 comprises an organic fiber material and a metal layer. The organic fiber material includes nylon, polyester, acrylic, polypropylene, etc. The metal layer comprises gold, silver, copper, aluminum, nickel, etc. The metal layer is deposited on the surface of the organic fiber material through methods such as vapor deposition, electroplating, or chemical plating. This surface layer 105 exhibits good durability and electrical conductivity. During preparation, the organic fiber material coated with the metal layer is woven and formed outside the hole injection layer 104 to form the surface layer 105.

[0111] In one embodiment of the invention, an encapsulation layer 106 is further included, the encapsulation layer 106 being disposed around the surface layer 105.

[0112] In this embodiment, the encapsulation layer 106 effectively encapsulates the electron injection layer 102, the light-emitting layer 103, and the hole injection layer 104 to prevent water and oxygen from directly contacting these layers and causing oxidation. During encapsulation, a fiber core 101, covering the electron injection layer 102, the light-emitting layer 103, the hole injection layer 104, and the surface layer 105, is placed in a mold. For example, the mold is a tube. The fiber core 101 is located at the center of the tube, and then adhesive is poured into the tube. After the adhesive cures, the encapsulation layer 106 is formed.

[0113] In one embodiment of the present invention, at least one of the electron injection layer 102, the light-emitting layer 103 and the hole injection layer 104 is a multilayer structure.

[0114] In this embodiment, the multilayer electron injection layer 102 can reduce the energy barrier of electron injection and enhance the stability of electrons during transmission, reduce electron loss during transmission, thereby improving the overall performance of the luminescent fiber.

[0115] The multi-layer light-emitting layer 103 can achieve higher brightness and richer colors by stacking light-emitting layers 103 of different colors or different luminous efficiencies. For example, by stacking red, green and blue three-primary-color light-emitting layers 103, the light-emitting fibers can present different colors.

[0116] The multilayer hole injection layer 104 can reduce the energy barrier of hole injection, improve the hole injection efficiency, and increase the recombination probability of holes and electrons in the light-emitting layer 103, thereby improving the luminous efficiency.

[0117] The number of layers in a multi-layer structure can be 2, 3, 4, 5, 6, etc. Those skilled in the art can configure it according to actual needs.

[0118] <Example>

[0119] In this embodiment, the fiber core 101 is aluminum fiber; the first active material is ZnO; the second active material is PPV; the third active material includes PEDOT and PSS in a mass ratio of 1:1; and the surface layer 105 is made of silver-plated nylon.

[0120] The method for preparing this luminescent fiber includes:

[0121] (1) Cleaning: The aluminum fibers were ultrasonically cleaned in acetone, ethanol and deionized water in sequence. The cleaning time of the aluminum fibers in each cleaning agent was 10 minutes.

[0122] (2) Preparation of the first slurry: ZnO nanoparticles were dispersed in isobutanol at a mass percentage of 5% and pulverized for 30 minutes using a cell pulverizer to obtain the first slurry.

[0123] (3) Preparation of electron injection layer 102: Aluminum fiber is dip-coated into the first slurry by dip coating. The aluminum fiber is moved at a speed of 6 mm per minute and annealed at 85°C for 15 minutes. Electron injection layer 102 is formed on the surface of aluminum fiber.

[0124] (4) Preparation of the second slurry: PPV is dispersed in toluene at a mass percentage of 6% and stirred at 60°C for 15 minutes to obtain the second slurry.

[0125] (5) Preparation of the light-emitting layer 103: Aluminum fibers are dip-coated into the second slurry by dip coating. The aluminum fibers are moved at a speed of 6 mm per minute and annealed at a temperature of 105°C for 10 minutes. The light-emitting layer 103 is formed outside the electron injection layer 102.

[0126] (6) Preparation of the third slurry: PEDOT and PSS were dispersed in deionized water at a mass percentage of 8%, and filtered with a filter cartridge with a pore size of 450 μm to remove larger particles, thus obtaining the third slurry.

[0127] (7) Preparation of hole injection layer 104: Aluminum fiber is dip-coated into the third slurry by dip coating. The aluminum fiber is moved at a speed of 6 mm per minute and annealed at 105°C for 15 minutes. Hole injection layer 104 is formed outside the light-emitting layer 103.

[0128] (8) Preparation of surface layer 105: Silver-plated nylon is wound around the hole injection layer 104 to obtain surface layer 105.

[0129] (9) Preparation of encapsulation layer 106: The silicone rubber is degassed under vacuum. The fiber core 101 is placed into the tube mold and fixed. The silicone rubber is injected into the tube mold and cured at room temperature to form encapsulation layer 106 on the surface layer 105. The tube mold is removed to obtain luminescent fibers.

[0130] The prepared single luminescent fiber was subjected to a direct current (DC) test. The voltage range was 3V-12V. During the test, the voltage was increased from 3V at a set frequency to test the starting voltage of the luminescent fiber and the change in brightness with voltage. The starting voltage of the luminescent fiber was found to be 3.5V. As shown in Figure 3, the brightness of the luminescent fiber prepared in this embodiment of the invention increases with increasing voltage. At 12V, the brightness of the luminescent fiber was 6400 lux / m². 2 After 20 hours of continuous power supply, the brightness of the luminescent fiber was measured again, and there was no decrease in brightness. This indicates that the luminescent fiber of this embodiment of the invention has good durability.

[0131] The above embodiments mainly describe the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. For the sake of brevity, they will not be elaborated here.

[0132] While specific embodiments of the invention have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of the invention. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. A method for preparing luminescent fibers, characterized in that, include: The fiber core is immersed in the first slurry, and after being removed, it undergoes a first annealing to form an electron injection layer on the outside of the fiber core. The fiber core is immersed in the second slurry, and after being removed, it is annealed a second time to form a light-emitting layer outside the electron injection layer; The fiber core is immersed in the third slurry, and after being removed, it is annealed for the third time to form a hole injection layer outside the light-emitting layer; A surface layer is formed outside the hole injection layer, wherein the fiber core wire is a first electrode and the surface layer is a second electrode.

2. The preparation method according to claim 1, characterized in that, The first slurry includes a first active substance and a first solvent. The first active substance includes at least one of ZnO, Ca, Mg / Ag alloy, Ba / Al alloy, SiO2, and LiF. The first solvent includes at least one of isopropanol, acetone, ethanol, and deionized water.

3. The preparation method according to claim 1, characterized in that, The temperature for the first annealing is 80℃-90℃, and the annealing time is 10-20 minutes.

4. The preparation method according to claim 1, characterized in that, The second slurry includes a second active substance and a second solvent. The second active substance includes at least one of PPV, titanium dioxide, and chromium sulfide. The second solvent includes an organic aromatic hydrocarbon.

5. The preparation method according to claim 1, characterized in that, The second annealing temperature is 100℃-110℃, and the annealing time is 8 minutes-20 minutes.

6. The preparation method according to claim 1, characterized in that, The third slurry includes a third active substance and a third solvent. The third active substance includes at least one of PEDOT, PSS, polyaniline, and polypyrrole. The third solvent includes at least one of deionized water and ethanol.

7. The preparation method according to claim 1, characterized in that, The third annealing temperature is 100℃-110℃, and the annealing time is 8 minutes-20 minutes.

8. The preparation method according to claim 1, characterized in that, At least one of the electron injection layer, the light-emitting layer, and the hole injection layer is a multilayer structure.

9. The preparation method according to claim 1, characterized in that, The surface layer is an organic fiber material coated with a metal layer.

10. The preparation method according to claim 1, characterized in that, After the step of forming a surface layer outside the hole injection layer, the method further includes: forming an encapsulation layer outside the surface layer.

11. The preparation method according to claim 1, characterized in that, The fiber core is sequentially immersed in the first slurry, the second slurry, and the third slurry, and the moving speed of the fiber core is 3 m / min to 10 m / min.

12. A luminescent fiber, characterized in that, The luminescent fiber is prepared according to any one of claims 1-11.

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