High-resolution quantum dot light-emitting device with light blocking charge blocking layer and preparation method of high-resolution quantum dot light-emitting device

Abstract

The invention relates to a high-resolution quantum dot light-emitting device with a light blocking charge blocking layer and a preparation method of the high-resolution quantum dot light-emitting device, and belongs to the technical field of photoelectric light-emitting and display devices. The quantum dot light-emitting device sequentially comprises a substrate with an etched indium tin oxide electrode pattern, a hole injection layer, a hole transport layer, a light blocking charge blocking layer, a quantum dot light-emitting layer, an electron transport layer and an electrode from bottom to top, and the light-blocking charge blocking layer is formed by assembling an insulating light-blocking material into a film by using a self-assembly technology. According to the invention, the self-assembly technology is utilized to realize the construction of the high-resolution light-blocking insulating material template, the process is simple, the material cost is extremely low, the good assembly of ultrahigh-resolution quantum dot pixels can be realized by controlling the surface of the template material, in addition, the light-blocking effect is achieved among the pixels of the prepared high-resolution quantum dot light-emitting device, and the light-emitting efficiency is improved. Therefore, the liquid crystal display has excellent display contrast, and has wide application prospects in the fields of quantum dot micro display, ultrahigh-resolution display, virtual augmented reality and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of optoelectronic light emitting and display devices, and in particular relates to a high-resolution quantum dot light emitting device with a light-blocking charge blocking layer and a preparation method thereof. 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] With the continuous development of near-eye display, display resolution has higher standards to meet the needs of information interaction. Existing technologies are difficult to meet the needs of ultra-high resolution. Quantum dots, as nano-scale semiconductor light-emitting materials, have luminescence performance that is almost unaffected by pixel size, and are a good way to achieve ultra-high resolution display.

[0004] The patterning technology of high-resolution quantum dot light-emitting diodes is relatively mature. However, there are few reports on high-resolution quantum dot light-emitting devices with excellent performance. The leakage current in the illegal light area and the optical crosstalk between pixels are important factors leading to poor performance. Solving these problems is of great significance to the development of quantum dot high-resolution display and the application of near-eye display. Summary of the invention

[0005] The purpose of the present invention is to provide a high-resolution quantum dot light-emitting device with a light-blocking and charge blocking layer and a preparation method thereof, wherein an insulating light-blocking material is assembled into a film by self-assembly technology, and is transferred to a hole transport layer using a patterned stamp by transfer printing technology to form a light-blocking and charge blocking layer, and quantum dots are filled into the light-blocking and charge blocking layer template by spin coating or in-place transfer to form a light-emitting array, and then the remaining functional layers are prepared by a solution method, and finally a metal electrode is evaporated to complete the preparation of a high-resolution light-emitting device.

[0006] To achieve the above-mentioned purpose, the technical solution of the present invention is: a high-resolution quantum dot light-emitting device with a light-blocking charge blocking layer, which comprises, from bottom to top, a substrate with an etched indium tin oxide electrode pattern, a hole injection layer, a hole transport layer, a light-blocking charge blocking layer, a quantum dot light-emitting layer, an electron transport layer, and an electrode; the light-blocking charge blocking layer is formed by assembling an insulating light-blocking material into a film using self-assembly technology and transferring it to the hole transport layer.

[0007] In one embodiment of the present invention, the hole injection layer material includes poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), phosphomolybdic acid, and vanadium oxide.

[0008] In one embodiment of the present invention, the hole transport layer material includes poly[(9,9-dioctylfluorene-2,7-diyl)-co-(4,4′-(N-(4-sec-butylphenyl)diphenylamine)] (TFB), poly(9-vinylcarbazole) (PVK), and poly[bis(4-phenyl)(4-butylphenyl)amine] (Poly-TPD).

[0009] In one embodiment of the present invention, the self-assembly technology is gas-liquid self-assembly, that is, the insulating light blocking material is spread on the interface of air and liquid subphases, spread into a film using the Marangoni effect, and extruded into a film by providing an additional tension gradient through a surfactant.

[0010] In one embodiment of the present invention, the insulating light blocking material includes insulating melanin, fullerene monomer material, or a composite material mixed with polymethyl methacrylate (PMMA) and polyvinyl butyral (PVB).

[0011] In one embodiment of the present invention, the quantum dots in the quantum dot light-emitting layer include core-shell quantum dots of cadmium selenide, indium phosphide, and zinc selenide.

[0012] In one embodiment of the present invention, the electron transport layer includes zinc oxide, tin oxide, and zinc magnesium oxide nanoparticles.

[0013] In one embodiment of the present invention, the electrode comprises silver or aluminum.

[0014] The present invention also provides a method for preparing a high-resolution quantum dot light-emitting device having a light-blocking charge blocking layer as described above, comprising the following steps: A. Spin coating the hole injection layer and hole transport layer on a substrate with an etched indium tin oxide (ITO) electrode pattern; B. Assemble the insulating light-blocking material into a film using self-assembly technology; C. Using a pre-made polydimethylsiloxane (PDMS) stamp with a pattern, the assembled insulating light-blocking material is transferred to the hole transport layer to form a light-blocking charge blocking layer; D. Filling the quantum dots into the light blocking charge blocking layer template pattern by spin coating or transfer printing; E, spin-coated electron transport layer; F. Evaporation electrode.

[0015] In one embodiment of the present invention, the polydimethylsiloxane stamp with the pattern is made by using a silicon template through a casting and demoulding process.

[0016] Compared with the prior art, the present invention has the following beneficial effects: the preparation process of a high-resolution quantum dot light-emitting device with a light-blocking charge blocking layer provided by the present invention is simple, the blocking layer material cost is low, and the light interference between the light-emitting pixels of the device can be effectively reduced, and the leakage current of the device is greatly reduced, thereby improving the display contrast. At the same time, by regulating the surface energy of the light-blocking material, the assembly of extremely small pattern sizes of quantum dots is promoted, thereby realizing ultra-high-resolution quantum dot light-emitting display. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a flow chart of a preferred embodiment of a high-resolution quantum dot light-emitting device with a light-blocking charge blocking layer and a preparation method thereof according to the present invention.

[0018] Figure 2 The schematic diagram is a principle process diagram of a high-resolution quantum dot light-emitting device with a light-blocking charge blocking layer and a preparation method thereof according to the present invention, including a light-blocking charge blocking layer assembly process, a transfer process and a device preparation process.

[0019] Figure 3 This is a demonstration of the effect of the luminous pattern example of the present invention. DETAILED DESCRIPTION

[0020] The technical solution of the present invention is described in detail below in conjunction with the accompanying drawings.

[0021] 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.

[0022] The present invention provides a high-resolution quantum dot light-emitting device with a light-blocking charge blocking layer, which comprises, from bottom to top, a substrate with an etched indium tin oxide electrode pattern, a hole injection layer, a hole transport layer, a light-blocking charge blocking layer, a quantum dot light-emitting layer, an electron transport layer, and an electrode; the light-blocking charge blocking layer is formed by assembling an insulating light-blocking material into a film using a self-assembly technology and transferring the film to the hole transport layer.

[0023] The present invention also provides a method for preparing a high-resolution quantum dot light-emitting device having a light-blocking charge blocking layer as described above, comprising the following steps: A. Spin coating the hole injection layer and hole transport layer on a substrate with an etched indium tin oxide (ITO) electrode pattern; B. Assemble the insulating light-blocking material into a film using self-assembly technology; C. Using a pre-made polydimethylsiloxane (PDMS) stamp with a pattern, the assembled insulating light-blocking material is transferred to the hole transport layer to form a light-blocking charge blocking layer; D. Filling the quantum dots into the light blocking charge blocking layer template pattern by spin coating or transfer printing; E, spin-coated electron transport layer; F. Evaporation electrode.

[0024] The following are specific implementation examples of the present invention.

[0025] like Figure 1 , 2 The figure shows a flow chart of a preferred embodiment of a high-resolution quantum dot light-emitting device with a light-blocking charge blocking layer and a method for preparing the same according to the present invention, which specifically includes: S1, spin coating a hole injection layer and a transport layer on a pre-cleaned ITO glass substrate; S2, spreading the light barrier layer material on the air-liquid interface for assembly; S3. Use a patterned PDMS stamp to pick up the light-blocking charge blocking layer material and transfer it to the hole transport layer to construct a light-blocking insulating layer template.

[0026] S4, filling quantum dots in the light blocking charge blocking layer template; S5, spin coating electron transport layer S6. Evaporating cathode electrode.

[0027] Furthermore, the hole injection layer material includes but is not limited to poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), phosphomolybdic acid, vanadium oxide, and the like.

[0028] Furthermore, the hole injection layer material is spin-coated at a speed of 3000-5000 r / min, an annealing temperature of 120-150 degrees Celsius, and a thickness of about 30-50 nanometers.

[0029] Furthermore, the hole transport layer material includes but is not limited to poly[(9,9-dioctylfluorene-2,7-diyl)-co-(4,4′-(N-(4-sec-butylphenyl)diphenylamine)] (TFB), poly(9-vinylcarbazole) (PVK), poly[bis(4-phenyl)(4-butylphenyl)amine] (Poly-TPD), etc.

[0030] Furthermore, the hole transport layer material is spin-coated at a speed of 3000 r / min, an annealing temperature of 120 degrees Celsius, and a thickness of about 30-50 nanometers.

[0031] Furthermore, the self-assembly technology is gas-liquid self-assembly, that is, the insulating light blocking material is spread on the interface of air and liquid subphases, such as air and water, and is slowly dripped to the interface of air and subphases using a micropipette. Due to the Marangoni effect, the molecules will quickly diffuse from the low tension area to the high tension area to spread into a film, and the surfactant can provide an additional tension gradient for extrusion into a film.

[0032] Furthermore, the insulating light blocking material should be soluble in low surface tension, low boiling point solvents, be volatile, and not react with subphase solutions, such as ethanol, hexane, chloroform, and the like.

[0033] Furthermore, the insulating light blocking material includes but is not limited to insulating melanin, fullerene monomer material, or a composite material doped with polymethyl methacrylate (PMMA) and polyvinyl butyral (PVB).

[0034] Furthermore, the PDMS stamp is made by a casting and demoulding process using a silicon template, wherein the ratio of PDMS stock solution to curing agent is 10:1, and is annealed at 120 degrees Celsius for two hours for curing.

[0035] Furthermore, the quantum dots include but are not limited to core-shell quantum dots such as cadmium selenide, indium phosphide, and zinc selenide.

[0036] Furthermore, the quantum dot filling method includes spin coating and transfer printing. Spin coating can achieve single-color filling, while transfer printing requires a certain alignment accuracy but can achieve multi-color filling.

[0037] Furthermore, the electron transport layer includes but is not limited to zinc oxide, tin oxide, zinc oxide magnesium nanoparticles, etc.

[0038] Furthermore, the electron transport layer material is spin-coated at a speed of 2000-3000 r / min, an annealing temperature of 80 degrees Celsius, and a thickness of about 45-75 nanometers.

[0039] Furthermore, the evaporated electrode includes but is not limited to silver, aluminum, etc.

[0040] Furthermore, the vacuum degree of the evaporation process is not less than 6×10 -4 Pa, the electrode thickness is about 100 nanometers.

[0041] In summary, the process of preparing the light-blocking charge blocking layer by self-assembly is simple, the blocking layer material cost is low, it can effectively reduce the light interference between the device's light-emitting pixels, and greatly reduce the device leakage current, improving the display contrast. It can realize the assembly of extremely small pattern sizes of quantum dots and realize ultra-high-resolution quantum dot luminescent display. It has a promoting significance for the progress of near-eye display devices and has potential application value in the field of high-resolution display.

[0042] Figure 3 This is a demonstration of the effect of the luminous pattern example of the present invention.

[0043] 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 high-resolution quantum dot light-emitting device having a light-blocking charge blocking layer, characterized in that: From bottom to top, it includes a substrate with an etched indium tin oxide electrode pattern, a hole injection layer, a hole transport layer, a light blocking charge blocking layer, a quantum dot light emitting layer, an electron transport layer, and an electrode; The light blocking charge blocking layer is formed by assembling an insulating light blocking material into a film using a self-assembly technique and transferring the film to the hole transport layer.

2. A high-resolution quantum dot light-emitting device with a light-blocking charge blocking layer according to claim 1, characterized in that: The hole injection layer material includes poly(3,4-ethylenedioxythiophene): polystyrene sulfonate, phosphomolybdic acid, and vanadium oxide.

3. A high-resolution quantum dot light-emitting device with a light-blocking charge blocking layer according to claim 1, characterized in that: The hole transport layer material includes poly[(9,9-dioctylfluorene-2,7-diyl)-co-(4,4′-(N-(4-sec-butylphenyl)diphenylamine)], poly(9-vinylcarbazole), and poly[bis(4-phenyl)(4-butylphenyl)amine].

4. The high-resolution quantum dot light-emitting device with a light-blocking charge blocking layer according to claim 1, characterized in that: The self-assembly technology is gas-liquid self-assembly, that is, the insulating light-blocking material is spread on the interface of air and liquid subphases, the Marangoni effect is used to spread the material into a film, and a surfactant is used to provide an additional tension gradient for extrusion into a film.

5. A high-resolution quantum dot light-emitting device with a light-blocking charge blocking layer according to claim 1 or 4, characterized in that: The insulating light blocking material includes insulating melanin, fullerene monomer material or a composite material mixed with polymethyl methacrylate and polyvinyl butyral.

6. The high-resolution quantum dot light-emitting device with a light-blocking charge blocking layer according to claim 1, characterized in that: The quantum dots in the quantum dot light-emitting layer include core-shell quantum dots of cadmium selenide, indium phosphide and zinc selenide.

7. The high-resolution quantum dot light-emitting device with a light-blocking charge blocking layer according to claim 1, characterized in that: The electron transport layer comprises zinc oxide, tin oxide, and zinc magnesium oxide nanoparticles.

8. The high-resolution quantum dot light-emitting device with a light-blocking charge blocking layer according to claim 1, characterized in that: The electrodes include silver and aluminum.

9. A method for preparing a high-resolution quantum dot light-emitting device having a light-blocking charge blocking layer according to any one of claims 1 to 8, characterized in that: The steps include: A. Spin coating a hole injection layer and a hole transport layer on a substrate with an etched indium tin oxide electrode pattern; B. Assemble the insulating light-blocking material into a film using self-assembly technology; C. Using a pre-made polydimethylsiloxane stamp with a pattern, the assembled insulating light blocking material is transferred to the hole transport layer to form a light blocking charge blocking layer; D. Filling the quantum dots into the light blocking charge blocking layer template pattern by spin coating or transfer printing; E, spin-coated electron transport layer; F. Evaporation electrode.

10. The method for preparing a high-resolution quantum dot light-emitting device having a light-blocking charge blocking layer according to claim 9, characterized in that: The polydimethylsiloxane stamp with the pattern is made by using a silicon template through a casting and demoulding process.

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