Method for realizing high-resolution full-color patterning by field-driven quantum dot selective region self-assembly

Abstract

The invention relates to a method for realizing high-resolution full-color patterning by field-driven quantum dot selective region self-assembly, and belongs to the technical field of photoelectric light emitting and display devices. The full-color patterning of the quantum dots is realized through the combination of the self-assembly of the single-layer interface of the quantum dots and a regioselective external electric field. A closely-arranged quantum dot single layer is prepared by utilizing an interface assembly technology, a local electric field is selectively applied by utilizing a driving substrate, the quantum dots at an interface are adsorbed to the driving substrate along the action direction of the electric field as the substrate is close to the quantum dots, and full-color patterning can be realized by changing the application area of the electric field and repeating the process. Full-color patterning of the quantum dots is achieved through electric field driving, the process is simple, and a complex alignment process is not needed. The thickness of the film can be easily controlled by transferring times through interface assembly of the quantum dots, waste of a solution method is avoided, and the cost is saved. The method has a wide application prospect in the fields of quantum dot micro display, color conversion, ultrahigh-resolution full-color display, virtual augmented reality and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of optoelectronic luminescence and display devices, and in particular relates to a method for realizing high-resolution full-color patterning by field-driven quantum dot selective regional self-assembly. Background Art

[0002] Quantum dots are a nanoscale semiconductor. As an inorganic semiconductor material, they are attracting more and more attention in the display field due to their unique photoluminescence and electroluminescence properties, including a wide excitation spectrum and narrow emission spectrum, high color purity, good optical stability, adjustable emission spectrum and long fluorescence lifetime.

[0003] Quantum dot display has important development prospects in the field of micro-display technology. Its optoelectronic properties are almost unaffected by its size. However, the full-color patterning of quantum dots currently still relies on high-precision alignment, and existing patterning technology makes it difficult to achieve full color in the ultra-high resolution field.

[0004] Existing patterning technologies are mostly limited to the light-emitting layer, and how to adapt them to the driver chip in the high-resolution field has always been an urgent problem to be solved. Summary of the invention

[0005] The purpose of the present invention is to provide a method for achieving high-resolution full-color patterning by field-driven quantum dot selective regional self-assembly, assembling quantum dots into a film through self-assembly technology, and utilizing an electric field applied in a selective region to drive the full-color assembly of quantum dots.

[0006] To achieve the above objectives, the technical solution of the present invention is: a method for achieving high-resolution full-color patterning by field-driven selective regional self-assembly of quantum dots, which realizes full-color patterning of quantum dots by combining single-layer interface self-assembly of quantum dots with regional selective external electric field.

[0007] In one embodiment of the present invention, the method comprises the following steps: A. treating the surface ligands of quantum dots to make them ionized and negatively charged and preparing a quantum dot solution; B. Using interface self-assembly to assemble quantum dots of corresponding colors into a film at the interface; C. applying an electric field to a preset pixel area of ​​the driving substrate; D. Place the driving substrate close to the surface of quantum dots to selectively pick up quantum dots; E. Repeat steps BD, change the pixel area where the electric field is applied, and pick up quantum dots of other colors.

[0008] In one embodiment of the present invention, the quantum dots are core-shell quantum dots.

[0009] In one embodiment of the present invention, the quantum dot material includes cadmium selenide (CdSe / ZnS), indium phosphide (InP / ZnS), zinc selenide (ZnSe), etc.

[0010] In one embodiment of the present invention, in step A, the quantum dots are subjected to surface ligand treatment to make them ionized and negatively charged, that is, a surface modifier including a carboxylic acid functional group is introduced to make the surface of the quantum dots negatively charged.

[0011] In one embodiment of the present invention, the surface modifier includes fatty acid salts, fatty amine salts, phosphates, and the like.

[0012] In one embodiment of the present invention, in step A, the quantum dot solution solvent is a low boiling point solvent such as hexane or toluene, which is easy to volatilize during the assembly process, and the concentration is 2-5 mg / ml.

[0013] In one embodiment of the present invention, the interfacial self-assembly technology is gas-liquid self-assembly, that is, the quantum dots are spread on the interface of gas and liquid subphases, and the spreading is carried out using the Marangoni effect, and the film can be extruded by providing an additional tension gradient through physical extrusion or surfactants.

[0014] In one embodiment of the present invention, the interfacial self-assembly is performed in the atmosphere or in an inert gas atmosphere, and the subphase used has a high surface tension, including but not limited to distilled water, ethylene glycol, glycerol, and the like.

[0015] In one embodiment of the present invention, the driving substrate is a high-resolution CMOS driving substrate.

[0016] Compared with the prior art, the present invention has the following beneficial effects: the method of the present invention has a simple preparation process and a high material utilization rate, does not require an additional high-precision alignment process when realizing multi-color assembly, and can accurately modulate the thickness of the quantum dot layer, and can realize the assembly of extremely small pattern sizes, which is applied to ultra-high resolution quantum dot luminescent displays. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic flow chart of the interface assembly of quantum dots in a method of the present invention for realizing high-resolution full-color patterning by field-driven selective regional self-assembly of quantum dots.

[0018] Figure 2 The diagram is a schematic diagram of the selective assembly of quantum dots and a driving substrate in a method of the present invention for realizing high-resolution full-color patterning by field-driven selective regional self-assembly of quantum dots. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is described in detail below in conjunction with the accompanying drawings.

[0020] In order to make the technical means and objectives of the present invention more clear, the present invention is further described below in conjunction with specific embodiments. The implementation methods described in the following exemplary embodiments are only examples of methods consistent with some aspects of the present invention described in detail in the attached claims. The described embodiments are only part of the embodiments of the present invention and not all of them. Based on the embodiments of the present invention, the remaining embodiments obtained by those skilled in the art without prior creative work are all within the scope of protection of the present invention.

[0021] The present invention provides a method for realizing high-resolution full-color patterning by field-driven selective regional self-assembly of quantum dots, and realizes full-color patterning of quantum dots by combining single-layer interface self-assembly of quantum dots with regional selective external electric field.

[0022] The specific implementation process of the method for realizing high-resolution full-color patterning by field-driven quantum dot selective regional self-assembly of the present invention includes: S1. Treat the surface ligands of quantum dots to make them ionized and negatively charged and prepare quantum dot solution.

[0023] S2. Use interface self-assembly to assemble quantum dots into a film at the interface.

[0024] S3. Applying an electric field to a preset pixel area of ​​the driving substrate.

[0025] S4. Place the driving substrate close to the surface of the quantum dots to selectively pick up the quantum dots.

[0026] S5. Repeat steps S2-S4, change the pixel area where the electric field is applied, and pick up quantum dots of other colors.

[0027] Furthermore, the method of field-driven quantum dot selective regional self-assembly to achieve high-resolution full-color patterning, wherein the quantum dot material is a core-shell quantum dot, including but not limited to cadmium selenide (CdSe / ZnS), indium phosphide (InP / ZnS), zinc selenide (ZnSe), etc.

[0028] Furthermore, in the method of achieving high-resolution full-color patterning by field-driven selective regional self-assembly of quantum dots, the quantum dots need to be surface treated to make them negatively charged, and the surface is negatively charged by introducing surface modifiers containing functional groups such as carboxylic acids, including fatty acid salts, fatty amine salts, phosphates, etc.

[0029] Furthermore, the quantum dot solution solvent is a low boiling point solvent such as hexane or toluene, which is easy to volatilize during the assembly process, and the concentration should not be too high, generally not exceeding 5 mg / ml.

[0030] Furthermore, the method of field-driven quantum dot selective regional self-assembly to achieve high-resolution full-color patterning, wherein the interface self-assembly technology is gas-liquid self-assembly, that is, the configured quantum dot solution is spread on the interface of the atmosphere and the liquid subphase. Due to the Marangoni effect, the solvent molecules quickly diffuse to the surrounding high-tension area, and the quantum dots also spread to the surrounding area. The film can be extruded by physical extrusion or surfactant to provide additional tension gradient, such as extrusion to the middle with sliding barriers on both sides (also called Langmuir-Blodgett). The film formation process is as follows Figure 1 shown.

[0031] Furthermore, the quantum dot self-assembly can be carried out in the atmosphere or in an inert gas atmosphere, and the subphase liquid used often has a high surface tension and does not react with the quantum dot spreading solvent, including but not limited to distilled water, ethylene glycol, glycerol, etc.

[0032] Furthermore, in the method of achieving high-resolution full-color patterning by field-driven quantum dot selective regional self-assembly, the driving substrate is a high-resolution CMOS driving substrate, and each pixel can be driven individually.

[0033] Furthermore, the process of using the driver chip to assemble quantum dots in multiple colors is as follows: Figure 2 As shown, a voltage is applied to the preset pixels on the driving substrate, and then the quantum dot interface (such as red quantum dots) is approached. Under the action of the electric field, the quantum dots are adsorbed to the designated pixel area, and the voltage application area is randomly changed, and quantum dots of the other two colors are assembled again.

[0034] In summary, the field-driven quantum dot selective regional self-assembly process described in the present invention is simple, has high material utilization, can accurately control the thickness of quantum dots through multiple assemblies, completely avoids the alignment process in the full-color assembly process, greatly reduces the difficulty of patterning, and directly matches the drive array. It has a driving significance for the patterning of extremely small-sized quantum dot devices and the development of micro-display technology. It is mainly used to promote the industrial application of quantum dot micro-display technology.

[0035] The above are preferred embodiments of the present invention. Any changes made according to the technical solution of the present invention, as long as the resulting functions do not exceed the scope of the technical solution of the present invention, belong to the protection scope of the present invention.

Claims

1. A method for achieving high-resolution full-color patterning by field-driven quantum dot selective regional self-assembly, characterized in that: Full-color patterning of quantum dots is achieved by combining single-layer interface self-assembly of quantum dots with a regionally selective external electric field.

2. The method for realizing high-resolution full-color patterning by field-driven quantum dot selective regional self-assembly according to claim 1, characterized in that: The method comprises the following steps: A. treating the surface ligands of quantum dots to make them ionized and negatively charged and preparing a quantum dot solution; B. Using interface self-assembly to assemble quantum dots of corresponding colors into a film at the interface; C. applying an electric field to a preset pixel area of ​​the driving substrate; D. Place the driving substrate close to the surface of quantum dots to selectively pick up quantum dots; E. Repeat steps BD, change the pixel area where the electric field is applied, and pick up quantum dots of other colors.

3. The method for realizing high-resolution full-color patterning by field-driven quantum dot selective regional self-assembly according to claim 1 or 2, characterized in that: The quantum dots are core-shell quantum dots.

4. The method for realizing high-resolution full-color patterning by field-driven quantum dot selective regional self-assembly according to claim 3, characterized in that: The quantum dot material includes cadmium selenide, indium phosphide and zinc selenide.

5. The method for realizing high-resolution full-color patterning by field-driven quantum dot selective regional self-assembly according to claim 2, characterized in that: In step A, the quantum dots are subjected to surface ligand treatment to make them ionized and negatively charged, that is, a surface modifier including a carboxylic acid functional group is introduced to make the surface of the quantum dots negatively charged.

6. The method for realizing high-resolution full-color patterning by field-driven quantum dot selective regional self-assembly according to claim 5, characterized in that: Surface modifiers include fatty acid salts, fatty amine salts, and phosphates.

7. The method for realizing high-resolution full-color patterning by field-driven quantum dot selective regional self-assembly according to claim 2, characterized in that: In step A, the quantum dot solution solvent uses a low boiling point solvent to facilitate volatilization during the assembly process, and the concentration is 2-5 mg / ml.

8. The method of realizing high-resolution full-color patterning by field-driven quantum dot selective regional self-assembly according to claim 2, characterized in that: The interfacial self-assembly technology is gas-liquid self-assembly, that is, spreading the quantum dots on the interface of gas and liquid subphases, using the Marangoni effect for spreading, and can be extruded into a film by physical extrusion or providing an additional tension gradient through a surfactant.

9. The method of realizing high-resolution full-color patterning by field-driven quantum dot selective regional self-assembly according to claim 2, characterized in that: The interface self-assembly is carried out in the air or in an inert gas atmosphere, and the subphase used has a high surface tension.

10. The method for realizing high-resolution full-color patterning by field-driven quantum dot selective regional self-assembly according to claim 1, characterized in that: The driving substrate is a high-resolution CMOS driving substrate.

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