Method and equipment for preparing high-resolution full-color quantum dot light-emitting diode

Abstract

The invention discloses a method and equipment for preparing a high-resolution full-color quantum dot light-emitting diode, and the method comprises the steps: preparing a substrate, a hole injection layer, a hole transmission layer, a quantum dot light-emitting layer, an electron transmission layer and the like, packaging the equipment, and the like. Therefore, in the quantum dot photoelectric field, compared with a traditional preparation method, the preparation method has unique advantages and innovation points, and the performance and the application prospect of the light emitting diode in the application fields of full-color display, background illumination, biological imaging and the like can be greatly improved.

Description

Technical Field

[0001] The present application relates to a method and equipment for preparing a high-resolution full-color quantum dot light-emitting diode, belonging to the technical field of light-emitting devices. Background Art

[0002] In the past related studies, no better method for preparing high-resolution full-color quantum dot light-emitting diodes has been proposed. Traditional technologies, such as photolithography, will greatly reduce the performance of quantum dots, spin coating preparation cannot achieve full-color display, and inkjet printing faces huge difficulties in nozzles and equipment below a few microns of pixels. In addition, the use of traditional transfer methods will make it difficult to align pixels, and quantum dots are easily damaged, and their electrical properties and stability are difficult to maintain. The life of the device is also affected, and it is not suitable for large-scale industrial production. The full-color quantum dot light-emitting diodes prepared by existing technologies have low resolution, poor precision and complex processes. It has always been difficult to achieve the preparation of high-resolution light-emitting devices. Summary of the invention

[0003] According to one aspect of the present application, a method for preparing a high-resolution full-color quantum dot light-emitting diode is provided, comprising the following steps:

[0004] S1: preparing a substrate and pre-treating the substrate to ensure that the surface is clean and free of contamination;

[0005] S2: spin coating a hole injection layer, spin coating a solution made of hole injection layer material on the pre-treated substrate, and performing annealing treatment on a heating table;

[0006] S3: spin coating a hole transport layer, spin coating and depositing a solution made of hole transport layer material on the surface of the hole injection layer to form an organic semiconductor film;

[0007] S4: preparing a quantum dot light-emitting layer, preparing a quantum dot light-emitting layer on the surface of the hole transport layer, comprising:

[0008] Processing the first quantum dots, dissolving the first quantum dots in a first solvent to form a densely arranged thin film on the liquid surface, sticking the thin film, performing pixel alignment using a positioning camera to complete pixel transfer, and transferring the thin film to the substrate to form a first quantum dot matrix;

[0009] Processing the second quantum dots, dissolving the second quantum dots in a second solvent to form a densely arranged thin film on the liquid surface, sticking the thin film, performing pixel alignment using a positioning camera to complete pixel transfer, and transferring the thin film to the substrate to form a second quantum dot matrix;

[0010] Processing the third quantum dots, dissolving the third quantum dots in a third solvent to form a densely arranged thin film on the liquid surface, sticking the thin film, performing pixel alignment using a positioning camera to complete pixel transfer, and transferring the thin film to the substrate to form a third quantum dot matrix;

[0011] The first quantum dot, the second quantum dot, and the third quantum dot have different colors;

[0012] The first quantum dot matrix, the second quantum dot matrix, and the third quantum dot matrix are regularly and alternately arranged in a horizontal direction on the surface of the hole transport layer;

[0013] After the processing is completed, the three pixels of red, green and blue are arranged into RGB arrangement, dense arrangement, PenTile arrangement and other pixel arrangements;

[0014] That is, the first quantum dot, the second quantum dot, and the third quantum dot are processed in the same manner, but the quantum dot types and specific arrangement directions are different;

[0015] S5: spin coating an electron transport layer, spin coating a solution made of an electron transport layer material on the surface of the quantum dot light-emitting layer, and performing an annealing treatment;

[0016] S6: Preparation of metal electrodes;

[0017] S7: Encapsulation.

[0018] Optionally, the pretreatment in step S1 includes cleaning and treating the surface of the substrate;

[0019] Preferably, the material of the substrate is ITO glass.

[0020] Optionally, the hole injection layer material in step S2 is selected from one of PEDOT:PSS, molybdenum oxide, nickel oxide, and cuprous thiocyanate;

[0021] Preferably, the hole injection layer has a thickness of 20 nm to 30 nm.

[0022] Optionally, the hole transport layer material in step S3 is selected from one or a mixture of polymer TFB, cross-linked TFB, Poly:TPD, PVK;

[0023] Preferably, the hole transport layer has a thickness of 40 nm to 50 nm.

[0024] Optionally, the quantum dots in step S4 are luminescent materials that can be processed by solution and can be film-drawn on the liquid surface, and are selected from one of cadmium quantum dots and indium phosphide quantum dots;

[0025] Preferably, in step S4, the first solvent, the second solvent, and the third solvent are all highly volatile and are independently selected from one of ethanol, ether, acetone, chloroform, and benzene;

[0026] Preferably, a PDMS template is used to adhere the film.

[0027] Optionally, the electron transport layer material in step S5 is selected from one of ZnO and zinc magnesium oxide;

[0028] Preferably, the thickness of the electron transport layer is 70 nm to 80 nm.

[0029] Optionally, the metal electrode in step S6 is a silver electrode, and the preparation method specifically includes:

[0030] Evaporation of silver electrodes is performed on an evaporation machine;

[0031] Preferably, the thickness of the silver electrode is 90 nm to 100 nm.

[0032] Optionally, in step S7, a transparent material is used to encapsulate the device;

[0033] Preferably, the transparent material is selected from polymer and glass.

[0034] The package protects and secures the circuit and provides moisture and environmental isolation.

[0035] The method provided in this application optimizes the arrangement of quantum dots, which helps to improve the resolution and stability of the light-emitting layer;

[0036] Compared with the traditional chip preparation process, the present application adopts chemical synthesis technology and film transfer technology, which requires fewer chemicals and generates relatively less waste during the preparation process, thus having better environmental performance;

[0037] The transfer method adopted in this application can greatly improve the transfer speed and transfer accuracy of quantum dots, and also increase the robustness and repeatability of the preparation process. Therefore, in the field of quantum dot optoelectronics, this application has unique advantages and innovations compared to traditional preparation methods, and can greatly improve the performance and application prospects of light-emitting diodes in full-color display, background lighting, biological imaging and other application fields.

[0038] In addition, the present application also provides a device for implementing the above method, including a shock absorbing platform;

[0039] The shock absorbing platform is provided with a motion component, and the motion component is movably provided with a positioning camera component and an observation camera component;

[0040] A transfer head assembly is arranged near the positioning camera assembly;

[0041] The shock absorbing platform is also provided with a film drawing machine and a bearing fixture assembly.

[0042] The positioning camera and observation camera should at least be able to see the pixel points and the positioning marks of the substrate, such as the need for objective lens 50 times or more magnification and CCD 10 times magnification.

[0043] Optionally, the motion assembly includes an X-axis track, dual-drive Y-axis tracks are movably arranged at both ends of the X-axis track, and a Z-axis track is movably arranged on the X-axis track;

[0044] The positioning camera assembly and the transfer head assembly are both arranged on the Z-axis track;

[0045] The observation camera assembly is arranged on the dual-drive Y-axis track;

[0046] The film stretching machine is arranged between the dual-drive Y-axis tracks.

[0047] The film drawing machine uses Langmuir-Blodgett film drawing machine, and the motion component is XYZ three-axis high-precision motion system;

[0048] After the quantum dots are formed into a thin film by a film-drawing machine, the quantum dots are adhered to the PDMS template set on the transfer head assembly, and the position of the transfer head and the substrate is observed by a high-resolution positioning camera. The contact between the PDMS template and the substrate during the descent of the Z-axis track is observed by a high-resolution observation camera. The pixel offset in the X / Y direction is adjusted by the supporting fixture assembly to realize the transfer of RGB three-color quantum dots.

[0049] For pixel offset adjustment, an example is given below. Assuming that the first quantum dot is transferred to the substrate, the stamp grabs the second color quantum dot (green). The substrate moves X=xx um, Y=xx um, and then the second quantum dot is transferred. The third quantum dot is also transferred according to the same method. The values ​​of X and Y are preset depending on the size of the red, green and blue pixels and the pixel arrangement.

[0050] The beneficial effects of this application include:

[0051] The present application provides a method for preparing a high-resolution full-color quantum dot light-emitting diode:

[0052] (1) The arrangement of quantum dots is optimized, and the pixels can be precisely aligned, which helps to improve the resolution and stability of the light-emitting layer and effectively prolong the life of the device;

[0053] (2) Compared with the traditional chip preparation process, the present application adopts chemical synthesis technology and film transfer technology, which requires fewer chemicals and generates relatively less waste during the preparation process, thus having better environmental performance;

[0054] (3) The transfer method used in this application can greatly improve the transfer speed and transfer accuracy of quantum dots, and also increase the robustness and repeatability of the preparation process. This method is simple, low-cost, fast, easy to operate and has a high yield, and is very suitable for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 A device for implementing a method for preparing a high-resolution full-color quantum dot light-emitting diode is provided in one embodiment of the present application.

[0056] List of parts and reference numerals:

[0057] 1. Shock-absorbing platform; 2. X-axis track; 3. Y-axis track; 4. Z-axis track; 5. Positioning camera assembly; 6. Transfer head assembly; 7. Observation camera assembly; 8. Film drawing machine; 9. Carrying fixture assembly. DETAILED DESCRIPTION

[0058] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0059] According to one embodiment of the present application, a method for preparing a high-resolution full-color quantum dot light-emitting diode is provided, comprising the following steps:

[0060] S1: preparing a substrate and pre-treating the substrate, including cleaning and treating the surface of the substrate to ensure that the surface is clean and free of contamination;

[0061] The material of the substrate is ITO glass;

[0062] S2: spin coating a hole injection layer, spin coating a solution made of hole injection layer material on the pre-treated substrate, and performing annealing treatment on a heating table;

[0063] The hole injection layer material is PEDOT:PSS;

[0064] The thickness of the hole injection layer is about 30 nm.

[0065] S3: spin coating a hole transport layer, spin coating and depositing a solution made of hole transport layer material on the surface of the hole injection layer to form an organic semiconductor film;

[0066] The hole transport layer material is TFB;

[0067] The thickness of the hole transport layer is about 50 nm;

[0068] S4: preparing a quantum dot light-emitting layer, preparing a quantum dot light-emitting layer on the surface of the hole transport layer, comprising:

[0069] Processing the first quantum dots, which are red quantum dots in this embodiment, dissolving the first quantum dots in a first solvent with strong volatility, ethanol in this embodiment, forming a densely arranged thin film on the liquid surface, sticking the thin film, using a positioning camera to perform pixel alignment and complete pixel transfer, and then transferring the thin film to the substrate to form a first quantum dot matrix;

[0070] Processing the second quantum dots, which are green quantum dots in this embodiment, in the same manner as above, to form a second quantum dot matrix;

[0071] Processing the third quantum dots, which are blue quantum dots in this embodiment, in the same manner as above, to form a third quantum dot matrix;

[0072] The first quantum dot matrix, the second quantum dot matrix, and the third quantum dot matrix are regularly and alternately arranged in a horizontal direction on the surface of the hole transport layer;

[0073] The quantum dots of the above colors are luminescent materials that can be processed by solution and can be drawn on the liquid surface. In this embodiment, cadmium quantum dots are selected;

[0074] Selecting a PDMS template to adhere the film;

[0075] S5: spin coating an electron transport layer, spin coating a solution made of an electron transport layer material on the surface of the quantum dot light-emitting layer, and performing an annealing treatment;

[0076] The electron transport layer material is ZnO;

[0077] The thickness of the electron transport layer is about 80 nm.

[0078] S6: preparing a metal electrode, wherein the metal electrode is a silver electrode, and performing evaporation deposition of the silver electrode on an evaporation machine, wherein the thickness of the silver electrode is 100 nm;

[0079] S7: Encapsulation: Encapsulate the device using transparent materials, and glass is selected in this embodiment.

[0080] The package protects and secures the circuit and provides moisture and environmental isolation.

[0081] The method provided in this application optimizes the arrangement of quantum dots, which helps to improve the resolution and stability of the light-emitting layer;

[0082] Compared with the traditional chip preparation process, the present application adopts chemical synthesis technology and film transfer technology, which requires fewer chemicals and generates relatively less waste during the preparation process, thus having better environmental performance;

[0083] The transfer method adopted in this application can greatly improve the transfer speed and transfer accuracy of quantum dots, and also increase the robustness and repeatability of the preparation process. Therefore, in the field of quantum dot optoelectronics, this application has unique advantages and innovations compared to traditional preparation methods, and can greatly improve the performance and application prospects of light-emitting diodes in full-color display, background lighting, biological imaging and other application fields.

[0084] In addition, the present application also provides a device for implementing the above method, such as Figure 1 As shown, it includes a shock absorbing platform 1;

[0085] The shock absorbing platform 1 is provided with a motion component, and the motion component is movably provided with a positioning camera component 5 and an observation camera component 7;

[0086] A transfer head assembly 6 is disposed near the positioning camera assembly 5;

[0087] The shock absorbing platform 1 is also provided with a film drawing machine 8 and a bearing fixture assembly 9 .

[0088] The motion assembly includes an X-axis track 2, dual-drive Y-axis tracks 3 are movably arranged at both ends of the X-axis track 2, and a Z-axis track 4 is movably arranged on the X-axis track 2;

[0089] The positioning camera assembly 5 and the transfer head assembly 6 are both arranged on the Z-axis track 4;

[0090] The observation camera assembly 7 is arranged on the dual-drive Y-axis track 3;

[0091] The film drawing machine 8 is arranged between the dual-drive Y-axis rails 3 .

[0092] The film drawing machine 8 uses a Langmuir-Blodgett film drawing machine 8, and the motion component is an XYZ three-axis high-precision motion system;

[0093] After the quantum dots are formed into a thin film by the film drawing machine 8, the quantum dots are adhered to the PDMS template set on the transfer head assembly 6, and the positions of the transfer head and the substrate are observed by a high-resolution positioning camera. The contact between the PDMS template and the substrate during the descent of the Z-axis track 4 is observed by a high-resolution observation camera. The pixel offset in the X / Y direction is adjusted by the supporting fixture assembly 9 to realize the transfer of RGB three-color quantum dots.

[0094] The above description is only a partial embodiment of the present application and does not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the above disclosed technical content to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for preparing high-resolution full-color quantum dot light-emitting diodes, It is characterized in that The steps include: S1: preparing a substrate and pre-treating the substrate to ensure that the surface is clean and free of contamination; S2: spin coating a hole injection layer, spin coating a solution made of hole injection layer material on the pre-treated substrate, and performing annealing treatment; S3: spin coating a hole transport layer, spin coating and depositing a solution made of hole transport layer material on the surface of the hole injection layer to form an organic semiconductor film; S4: preparing a quantum dot light-emitting layer, preparing a quantum dot light-emitting layer on the surface of the hole transport layer, comprising: Processing the first quantum dots, dissolving the first quantum dots in a first solvent to form a densely arranged thin film on the liquid surface, sticking the thin film, performing pixel alignment using a positioning camera to complete pixel transfer, and transferring the thin film to the substrate to form a first quantum dot matrix; Processing the second quantum dots, dissolving the second quantum dots in a second solvent to form a densely arranged thin film on the liquid surface, sticking the thin film, performing pixel alignment using a positioning camera to complete pixel transfer, and transferring the thin film to the substrate to form a second quantum dot matrix; Processing the third quantum dots, dissolving the third quantum dots in a third solvent to form a densely arranged thin film on the liquid surface, sticking the thin film, performing pixel alignment using a positioning camera to complete pixel transfer, and transferring the thin film to the substrate to form a third quantum dot matrix; The first quantum dot, the second quantum dot, and the third quantum dot have different colors; The first quantum dot matrix, the second quantum dot matrix, and the third quantum dot matrix are regularly and alternately arranged in a horizontal direction on the surface of the hole transport layer; S5: spin coating an electron transport layer, spin coating a solution made of an electron transport layer material on the surface of the quantum dot light-emitting layer, and performing an annealing treatment; S6: Preparation of metal electrodes; S7: Encapsulation.

2. A method for preparing a high-resolution full-color quantum dot light-emitting diode according to claim 1, It is characterized in that The pretreatment in step S1 includes cleaning and treating the surface of the substrate; Preferably, the material of the substrate is ITO glass.

3. A method for preparing a high-resolution full-color quantum dot light-emitting diode according to claim 1, It is characterized in that The hole injection layer material in step S2 is selected from one of PEDOT:PSS, molybdenum oxide, nickel oxide, and cuprous thiocyanate; Preferably, the hole injection layer has a thickness of 20 nm to 30 nm.

4. A method for preparing a high-resolution full-color quantum dot light-emitting diode according to claim 1, It is characterized in that The hole transport layer material in step S3 is selected from one or a mixture of polymer TFB, cross-linked TFB, Poly:TPD, PVK; Preferably, the hole transport layer has a thickness of 40 nm to 50 nm.

5. A method for preparing a high-resolution full-color quantum dot light-emitting diode according to claim 1, It is characterized in that The quantum dots in step S4 are luminescent materials, selected from cadmium quantum dots and indium phosphide quantum dots; Preferably, in step S4, the first solvent, the second solvent, and the third solvent are independently selected from one of ethanol, ether, acetone, chloroform, and benzene; Preferably, a PDMS template is used to adhere the film.

6. A method for preparing a high-resolution full-color quantum dot light-emitting diode according to claim 1, It is characterized in that The electron transport layer material in step S5 is selected from one of ZnO and zinc magnesium oxide; Preferably, the thickness of the electron transport layer is 70 nm to 80 nm.

7. A method for preparing a high-resolution full-color quantum dot light-emitting diode according to claim 1, It is characterized in that The metal electrode in step S6 is a silver electrode, and the preparation method specifically includes: Evaporation of silver electrodes is performed on an evaporation machine; Preferably, the thickness of the silver electrode is 90 nm to 100 nm.

8. The method for preparing a high-resolution full-color quantum dot light-emitting diode according to claim 1, It is characterized in that In step S7, the device is encapsulated using a transparent material; Preferably, the transparent material is selected from polymer and glass.

9. A device for implementing a method for preparing a high-resolution full-color quantum dot light-emitting diode according to any one of claims 1 to 8, It is characterized in that Includes shock-absorbing platform; The shock absorbing platform is provided with a motion component, and the motion component is movably provided with a positioning camera component and an observation camera component; A transfer head assembly is arranged near the positioning camera assembly; The shock absorbing platform is also provided with a film drawing machine and a bearing fixture assembly.

10. The device according to claim 9, It is characterized in that The motion assembly includes an X-axis track, dual-drive Y-axis tracks are movably arranged at both ends of the X-axis track, and a Z-axis track is movably arranged on the X-axis track; The positioning camera assembly and the transfer head assembly are both arranged on the Z-axis track; The observation camera assembly is arranged on the dual-drive Y-axis track; The film stretching machine is arranged between the dual-drive Y-axis tracks.

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