Patterned quantum dot light-emitting devices and their fabrication methods

Abstract

This invention relates to a patterned quantum dot light-emitting device and its fabrication method. The patterned quantum dot light-emitting device includes a driving circuit substrate, a light-emitting layer structure, and an electrode layer. The light-emitting layer structure includes a hole injection layer, a hole transport layer, a quantum dot light-emitting layer, and an electron transport layer stacked sequentially, with the latter positioned between the driving circuit substrate and the electrode layer. In the fabrication process of the patterned quantum dots in this application, during the deposition of the layer structure, the hole transport layer and subsequent layers (in the deposition order) are irradiated with lasers of different intensities. The irradiation extends to the hole transport layer, forming staggered and arrayed current blocking portions and pixel units, thus pixelating the hole transport layer and completing the entire fabrication process of the patterned quantum dot light-emitting device. This application can reduce the complexity of the patterned quantum dot light-emitting device process and minimize damage to the quantum dots in the light-emitting layer, thereby achieving high-resolution patterning.

Description

Technical Field

[0001] This invention relates to the field of quantum dot technology, and in particular to a patterned quantum dot light-emitting device and its fabrication method. Background Technology

[0002] Quantum dot light-emitting diodes (QLEDs) have attracted widespread attention due to their significant characteristics, including tunable emission wavelength, high color purity, high brightness, low power consumption, and low-cost manufacturing potential. A key step in bringing QLED displays to commercial applications is the pixelation of QLED devices. Current research on QLED pixelation mainly focuses on the emitter layer (EML), employing methods such as transfer printing, photolithography, and selective electrophoretic deposition. Transfer printing is prone to damaging the quantum dot layer during the transfer process; the chemicals and ultraviolet light used in photolithography can damage the quantum dot material; and selective electrophoretic deposition requires surface treatment of the quantum dots, which can also damage the quantum dot layer. Therefore, existing technologies inevitably cause some damage to the quantum dot layer or the quantum dot material during their respective processes, reducing the stability and luminous efficiency of the quantum dots, thus affecting the optical and electrical performance of the quantum dot LED. Furthermore, the uniformity and control of existing processes are difficult, making them unsuitable for large-area production. Furthermore, in areas without quantum dots after quantum dot patterning, the hole transport layer (HTL) will directly contact the electron transport layer (ETL), which may create a low-resistance current leakage path, leading to a significant reduction in device performance. Summary of the Invention

[0003] The present invention provides a patterned quantum dot light-emitting device and its fabrication method to solve the technical problem that, in areas without quantum dots after quantum dot patterning, the hole transport layer will directly contact the electron transport layer, which may create a low-resistance current leakage path and lead to a significant reduction in device performance.

[0004] First aspect

[0005] This invention provides a method for preparing patterned quantum dots, comprising the following steps:

[0006] Prepare the drive circuit board and clean and pre-treat it;

[0007] A hole injection layer, a hole transport layer, a quantum dot light-emitting layer, an electron transport layer, and an electrode layer are sequentially deposited on one side of the driving circuit substrate to obtain an upright quantum dot display device;

[0008] In the process of fabricating the upright quantum dot display device, at least the hole transport layer is irradiated with a laser to form staggered and arrayed current blocking parts and hole pixel units on the hole transport layer. The current blocking parts are insulating regions, and the hole pixel units allow current to pass through, thereby making the hole transport layer pixelated to prepare an upright patterned quantum dot light-emitting device.

[0009] This invention provides a method for preparing patterned quantum dots, comprising the following steps:

[0010] Prepare the drive circuit board and clean and pre-treat it;

[0011] An inverted quantum dot display device is obtained by sequentially depositing an electron transport layer, a quantum dot light-emitting layer, a hole transport layer, a hole injection layer and an electrode layer on one side of the driving circuit substrate.

[0012] In the process of fabricating the inverted quantum dot display device, at least the hole transport layer is irradiated with a laser to form staggered and arrayed current blocking parts and hole pixel units on the hole transport layer. The current blocking parts are insulating regions, and the hole pixel units allow current to pass through, thereby pixelating the hole transport layer to prepare an inverted patterned quantum dot light-emitting device.

[0013] In one embodiment, the laser irradiation step includes:

[0014] The target hierarchical structure is deposited layer by layer on one side of the driving circuit substrate, and the target hierarchical structure is deposited and formed after the hole transport layer;

[0015] A preset pattern is imported into the device, and a laser is used to irradiate one side of the upper surface of the target hierarchical structure to destroy and degrade the hierarchical structure in the irradiated area to form the current blocking part. The area not irradiated by the laser remains unchanged and forms the hole pixel unit in the hole transport layer.

[0016] In one embodiment, the step of depositing the quantum dot light-emitting layer includes: spin-coating monochromatic quantum dots as the quantum dot light-emitting layer in a glove box to obtain a monochromatic patterned quantum dot light-emitting device.

[0017] In one embodiment, the step of depositing the quantum dot light-emitting layer includes: spin-coating quantum dots that can be used for UV cross-linking and curing in a glove box, forming a patterned quantum dot layer by photolithography; repeating the spin-coating and photolithography operations to pattern quantum dots of two other colors to form a full-color quantum dot pixel layer as the quantum dot light-emitting layer, thereby obtaining a full-color patterned quantum dot light-emitting device.

[0018] In one embodiment, the quantum dot light-emitting layer forms a plurality of spaced and arrayed light-emitting pixel units, each of the light-emitting pixel units being paired with a hole pixel unit.

[0019] Second aspect

[0020] This invention provides a patterned quantum dot light-emitting device prepared by the preparation method of any of the preceding embodiments, comprising:

[0021] Drive circuit board;

[0022] A light-emitting layer structure, comprising a hole injection layer, a hole transport layer, a quantum dot light-emitting layer and an electron transport layer stacked sequentially, wherein the hole injection layer or the electron transport layer is stacked on one side of the driven circuit substrate;

[0023] An electrode layer is stacked on the side of the light-emitting layer structure opposite to the driving circuit substrate;

[0024] The patterned quantum dot light-emitting device further includes staggered and arrayed current blocking portions and hole pixel units, wherein the current blocking portions are insulating regions and the hole pixel units allow current to pass through; in the direction of stacking of the light-emitting layer structure, the current blocking portions and the hole pixel units extend at least to opposite sides of the hole transport layer.

[0025] In one embodiment, the quantum dot light-emitting layer emits monochromatic light.

[0026] In one embodiment, the quantum dot light-emitting layer emits colored light and includes multiple spaced and arrayed light-emitting pixel units. The multiple light-emitting pixel units can emit three colors of light, and any three adjacent light-emitting pixel units are arranged in an RGB array.

[0027] In one embodiment, the light-emitting pixel unit and the hole pixel unit are aligned one-to-one in the direction along which the light-emitting hierarchy is stacked;

[0028] In one embodiment, the gap between two adjacent light-emitting pixel units is partially filled by the electron transport layer.

[0029] As can be seen from the above technical solutions, the embodiments of the present invention have at least the following advantages and positive effects:

[0030] This invention provides a patterned quantum dot light-emitting device and its fabrication method. On one hand, by irradiating the hole transport layer with a laser, regions with different conductivity can be formed on the hole transport layer, creating hole pixel units. This eliminates the need for patterning the quantum dot light-emitting layer, allowing for the direct fabrication of a monochromatic patterned quantum dot light-emitting device. This method only requires simple laser irradiation during the deposition of the light-emitting layer structure to complete the fabrication of the desired patterned quantum dot light-emitting device, greatly simplifying the fabrication process and reducing damage to the quantum dots in the light-emitting layer, thereby achieving high-resolution patterning. On the other hand, for full-color patterned quantum dot light-emitting devices, laser irradiation oxidizes and degrades the hole transport layer, forming current-blocking regions in the irradiated area. This blocks electron-hole recombination, reduces device leakage, and thus improves the photoelectric performance of the patterned quantum dot light-emitting device. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the hierarchical structure of the patterned quantum dot light-emitting device in the upright position according to this application;

[0033] Figure 2 A schematic diagram of the hierarchical structure of the inverted patterned quantum dot light-emitting device;

[0034] Figure 3 A schematic diagram of the hierarchical structure of a full-color patterned quantum dot light-emitting device in an upright position;

[0035] Figure 4 This is a schematic diagram of laser irradiation of the hole transport layer;

[0036] Figure 5 This is a flowchart illustrating the fabrication process of an upright patterned quantum dot light-emitting device.

[0037] Figure 6 This is a flowchart illustrating the fabrication process of an inverted patterned quantum dot light-emitting device.

[0038] The annotations in the attached figures are explained as follows:

[0039] 10. Patterned quantum dot light-emitting device; 100. Driving circuit board; 200. Hole injection layer; 300. Hole transport layer; 310. Current blocking part; 320. Hole pixel unit; 400. Quantum dot light-emitting layer; 410. Light-emitting pixel unit; 500. Electron transport layer; 600. Electrode layer. Detailed Implementation

[0040] Typical embodiments embodying the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various variations in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations herein are for illustrative purposes only and not intended to limit the present invention.

[0041] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0042] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "setup," and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0043] refer to Figure 1 This application provides a patterned quantum dot light-emitting device 10 (hereinafter referred to as: light-emitting device 10). The light-emitting device 10 achieves pixelation by irradiating a hole transport layer 300 with a laser, thereby patterning the hole transport layer 300. Here, the laser can selectively oxidize and degrade a portion of the hole transport layer 300 structure, reducing the conductivity of the laser-irradiated area, while the area not irradiated by the laser remains unaffected. This method eliminates the need for complex masks or multi-step processes for pixelation. It should be understood that in this application, laser irradiation is only used for photolithography to pattern the hole transport layer 300. In other embodiments, ultraviolet light can also be used for photolithography of the hole transport layer 300. Therefore, in this application, the light source for photolithography of the hole transport layer 300 is not limited.

[0044] Reference Figure 1 and Figure 2Depending on the order of the hierarchical structure and the different performance, the light-emitting device 10 includes an upright light-emitting device 10 and an inverted light-emitting device 10. Figure 1 As illustrated, the upright light-emitting device 10 includes a driving circuit substrate 100, a hole injection layer 200, a hole transport layer 300, a quantum dot light-emitting layer 400, an electron transport layer 500, and an electrode layer 600 stacked layer by layer. Figure 2 As illustrated, the inverted light-emitting device 10 is essentially a device where the positions of the driving circuit substrate 100 and the electrode layer 600 are interchanged. The inverted light-emitting device 10 includes a driving circuit substrate 100, an electron transport layer 500, a quantum dot light-emitting layer 400, a hole transport layer 300, a hole injection layer 200, and an electrode layer 600, stacked layer by layer. The hole injection layer 200, hole transport layer 300, quantum dot light-emitting layer 400, and electron transport layer 500 form a light-emitting hierarchical structure, which is located between the driving circuit substrate 100 and the electrode layer 600; that is, the electrode layer 600 is stacked on the side of the light-emitting hierarchical structure facing away from the driving circuit substrate 100. It should be noted that the driving circuit board 100 has electrode structures (anode and cathode structures) with opposite polarities to the electrode layer 600, therefore the light-emitting hierarchical structure is stacked between the cathode and the anode. For the upright light-emitting device 10, the driving circuit board 100 is provided with an anode structure, the electrode layer 600 is a cathode structure, and one side of the hole injection layer 200 is stacked on the anode structure of the driving circuit board 100; for the inverted light-emitting device 10, the driving circuit board 100 is provided with a cathode structure, the electrode layer 600 is an anode structure, and one side of the electron transport layer 500 is stacked on the cathode structure of the driving circuit board 100.

[0045] In addition, in conjunction with references Figure 1 and Figure 3 The hole transport layer 300 of the light-emitting device 10 also includes staggered and arrayed current blocking portions 310 and hole pixel units 320. The current blocking portions 310 are insulating regions formed by reducing the conductivity of a portion of the hole transport layer 300 after laser irradiation, which can block the passage of current. The hole pixel units 320 are non-insulating regions formed by preserving the original state of a portion of the hole transport layer 300 that is not irradiated by laser, which can allow current to pass through. In one embodiment, the laser only irradiates the hole transport layer 300, and the current blocking portions 310 and hole pixel units 320 are formed exactly on the hole transport layer 300, that is, in the direction of stacking of the light-emitting layer structure, the current blocking portions 310 and hole pixel units 320 extend to opposite sides of the hole transport layer 300.

[0046] It should be understood that, in this application, provided that the laser irradiation time and intensity are sufficient, in order to achieve patterning of the hole transport layer 300, the laser irradiation can occur on the upper surface of any layer structure deposited after the hole transport layer 300 is deposited or subsequently deposited. In the upright light-emitting device 10, the laser irradiation can occur after the hole transport layer 300 is deposited, or after the quantum dot light-emitting layer 400 is deposited, or after the electron transport layer 500 is deposited, or after the electrode layer 600 is deposited. In the inverted light-emitting device 10, the laser irradiation can occur after the hole transport layer 300 is deposited, or after the hole injection layer 200 is deposited, or after the electrode layer 600 is deposited. The laser irradiation penetrates from top to bottom into the hole transport layer 300 to form staggered and arrayed current blocking portions 310 and hole pixel units 320 in the hole transport layer 300.

[0047] The following example, which involves irradiating the hole transport layer 300 with laser light only in the upright light-emitting device 10, further illustrates this solution.

[0048] Reference Figure 1 and Figure 4 Depending on the composition and luminescence characteristics of the quantum dot luminescent layer 400, the luminescent device 10 of this application includes a monochromatic luminescent device 10. Figure 1 (as shown) and full-color light-emitting device 10 ( Figure 4 (As shown). Figure 1 As illustrated, in the monochromatic light-emitting device 10, the quantum dot light-emitting layer 400 includes only one color of light-emitting pixels, and the quantum dot light-emitting layer 400 emits light in a monochromatic manner; Figure 4 As illustrated, in the full-color light-emitting device 10, the quantum dot light-emitting layer 400 includes multiple spaced and arrayed light-emitting pixel units 410 of different colors. The multiple light-emitting pixel units 410 can emit three colors of light (RGB three-color light), and any three adjacent light-emitting pixel units 410 are arranged in an RGB array. The quantum dot light-emitting layer 400 realizes color light emission to achieve full-color display of the light-emitting device 10.

[0049] Continue to refer to Figure 4In this embodiment, in the colored light-emitting device 10, the gap width between two adjacent light-emitting pixel units 410 is no greater than the width of the current blocking portion 310 in the direction of stacking along the light-emitting layer structure. That is, the pixel size of the hole transport layer 300 is slightly smaller than the pixel size of the quantum dot light-emitting layer 400, and the pattern of the hole transport layer 300 is the same as the pattern on the quantum dot light-emitting layer 400. Therefore, the light-emitting pixel units 410 and the hole pixel units 320 are aligned one-to-one. In addition, the gap between two adjacent light-emitting pixel units 410 is partially filled by the electron transport layer 500. Of course, in other embodiments, the gap between two adjacent light-emitting pixel units 410 can also be filled by other materials capable of transporting electrons.

[0050] In this application, the selection of materials for the hierarchical structure in the light-emitting device 10 includes, but is not limited to, high-conductivity PEDOT, PSS, and NiO. X Materials such as MoO3; the hole transport layer 300 material can be a conventional hole transport layer 300 material in the art, including but not limited to TFB and PVK, poly-TPD, PF8Cz, etc.; the quantum dot light-emitting layer 400 material can be a group II-VI compound semiconductor, such as CdS, CdSe, CdS / ZnS, CdSe / ZnS or CdSe / CdS / ZnS, etc., or a group III-V compound semiconductor, such as InP, etc., and can also include perovskite quantum dot materials, organic-inorganic perovskite quantum dot materials, all-inorganic perovskite quantum dot materials; the electron transport layer 500 material can be a conventional electron transport material in the art, including but not limited to ZnO and ZnMgO, etc.; the top electrode layer 600 includes but is not limited to one or more of indium tin oxide (ITO), fluorine-doped tin oxide (FTO), indium zinc oxide (IZO), aluminum, silver, etc.

[0051] The lasers used in this application include continuous-wave lasers, nanosecond, picosecond, and femtosecond pulsed lasers. The laser wavelength ranges from 300 nm to 800 nm, the power ranges from 0.01 mW to 100 W, and the laser energy density ranges from 5 to 10000 kJ / cm². 2 The laser spot size is 0.5–10 μm. It should be noted that, in this application, since the type of laser is not limited, the relevant operating parameters for laser irradiation are not limited.

[0052] Secondly, this application also provides a method for fabricating a patterned quantum dot light-emitting device 10 (hereinafter referred to as: light-emitting device 10), which mainly includes two operational steps: sequential stacking and deposition, and laser irradiation. Since laser irradiation can occur on one or more layers, in order to clearly describe the fabrication process, this embodiment will be described in detail with laser irradiation occurring only in the hole transport layer 300. In addition, the light-emitting device 10 includes an upright light-emitting device 10 and an inverted light-emitting device 10, and the fabrication processes of the upright device and the inverted device are as follows.

[0053] Reference Figure 1 and Figure 5 The method for fabricating the upright light-emitting device 10 includes the following steps:

[0054] S10: Fabrication of drive circuit substrate 100;

[0055] S20: Deposited hole injection layer 200;

[0056] S30: Deposited hole transport layer 300;

[0057] S40: Laser irradiation of hole transport layer 300;

[0058] S50: Deposited quantum dot light-emitting layer 400;

[0059] S60: Deposited electron transport layer 500;

[0060] S70: Deposited electrode layer 600;

[0061] The above steps S20, S30, S50, S60, and S70 sequentially deposit a hole injection layer 200, a hole transport layer 300, a quantum dot light-emitting layer 400, an electron transport layer 500, and an electrode layer 600 on one side of the driving circuit substrate 100 to obtain a positive quantum dot display device (without pixelation). During the fabrication of this positive quantum dot display device, the hole transport layer 300 is at least irradiated with a laser to form interleaved and arrayed current blocking portions 310 and hole pixel units 320 on the hole transport layer 300. The current blocking portions 310 are insulating regions, and the hole pixel units 320 allow current to pass through, thereby pixelating the hole transport layer 300 to prepare a positive light-emitting device 10.

[0062] Specifically, in step S10, the drive circuit substrate 100 is prepared and cleaned and pretreated. First, the substrate is ultrasonically cleaned for 15 minutes using acetone, ethanol, and deionized water. Then, it is placed in an oven to dry for 30 minutes. Next, the substrate is treated with oxygen plasma or UV-ozone for 5 minutes. It should be noted that in the above steps, ultrasonic cleaning and drying of the substrate are for cleaning and removing impurities, while treatment with oxygen plasma or UV-ozone is to change the wettability of the substrate.

[0063] In step S20, a layer of PEDOT:PSS is spin-coated on one side of the anode circuit of the drive circuit substrate 100 in air and annealed at 130 degrees Celsius in air for 20 minutes to obtain a hole injection layer 200, wherein PEDOT:PSS is an aqueous solution of a polymer with high conductivity.

[0064] In step S30, the driving circuit substrate 100 is placed in a glove box, and a layer of TFB is spin-coated on the upper surface of the hole injection layer 200 in the inert atmosphere of the glove box, and then annealed at 120 degrees for 20 minutes to obtain the hole transport layer 300. TFB is a conductive polymer and is a commonly used material for hole transport layer 300.

[0065] In step S40, the driving circuit substrate 100 with the hole injection layer 200 and hole transport layer 300 deposited is placed on the laser direct writing stage, and the preset pattern is imported into the device. Figure 5 The laser irradiation path shown uses a 405nm continuous wave laser to irradiate the hole transport layer 300, damaging and degrading the hole transport layer 300 in the irradiated area to obtain an insulating current blocking portion 310. The non-irradiated area remains unchanged and allows current to pass through, forming hole pixel units 320 in the hole transport layer 300. Figure 3 The current blocking section 310 and the hole pixel unit 320 shown are arranged in an array on the hole transport layer 300, with alternating intervals. It should be noted that the laser irradiation method here includes, but is not limited to, continuous laser, pulsed laser, etc.

[0066] In step S50, a quantum dot layer is spin-coated onto the upper surface of the hole transport layer 300 after laser irradiation in the inert atmosphere of a glove box to form a quantum dot emitting layer 400. This quantum dot emitting layer 400 can emit monochromatic light or color light. It should be noted that when the quantum dot emitting layer 400 is monochromatic, in other embodiments, monochromatic quantum dots can also be prepared using methods such as inkjet printing, nanoimprinting, and blade coating. That is, the method for preparing monochromatic quantum dots is not limited in this application.

[0067] In step S60, ZnO solution is spin-coated onto the upper surface of the quantum dot light-emitting layer 400 in the inert atmosphere of the glove box, and then annealed at 100 degrees Celsius in the inert atmosphere of the glove box for 10 minutes to obtain the electron transport layer 500.

[0068] In step S70, Al is finally deposited on the upper surface of the electron transport layer 500 as the top electrode layer 600 to complete the fabrication of the upright light-emitting device 10.

[0069] Reference Figure 2 and Figure 6 The method for fabricating the inverted light-emitting device 10 includes the following steps:

[0070] S10: Prepare the drive circuit board 100;

[0071] S20: Deposited electron transport layer 500;

[0072] S30: Deposited quantum dot light-emitting layer 400;

[0073] S40: Deposited hole transport layer 300

[0074] S50: Laser irradiation of hole transport layer 300;

[0075] S60: Deposited hole injection layer 200;

[0076] S70: Deposited electrode layer 600.

[0077] In the above steps S20, S30, S40, S60, and S70, an electron transport layer 500, a quantum dot light-emitting layer 400, a hole transport layer 300, a hole injection layer 200, and an electrode layer 600 are deposited sequentially on one side of the driving circuit substrate 100 to obtain an inverted quantum dot display device (without pixelation). During the fabrication of this inverted quantum dot display device, the hole transport layer 300 is at least irradiated with a laser to form interleaved and arrayed current blocking portions 310 and hole pixel units 320 on the hole transport layer 300. The current blocking portions 310 are insulating regions, and the hole pixel units 320 allow current to pass through, thereby pixelating the hole transport layer 300 to prepare an inverted light-emitting device 10.

[0078] Specifically, in step S10, a drive circuit substrate 100 is prepared and cleaned and pretreated to obtain the drive circuit substrate. First, the substrate is ultrasonically cleaned for 15 minutes using acetone, ethanol, and deionized water. Then, it is placed in an oven to dry for 30 minutes. Next, the substrate is treated with oxygen plasma or UV-ozone for 5 minutes. It should be noted that in the above steps, ultrasonic cleaning and drying of the substrate are for cleaning and removing impurities, while treatment with oxygen plasma or UV-ozone is to change the wettability of the substrate.

[0079] In step S20, the drive circuit substrate 100 is placed in a glove box, and a ZnO solution is spin-coated on one side of the anode circuit of the drive circuit substrate 100 in the inert atmosphere of the glove box. The solution is then annealed in the inert atmosphere of the glove box for 10 minutes to obtain the electron transport layer 500.

[0080] In step S30, a quantum dot layer is spin-coated onto the upper surface of the electron transport layer 500 in the inert atmosphere of the glove box as a quantum dot light-emitting layer 400. Here, the quantum dot light-emitting layer 400 can emit monochromatic light or colored light.

[0081] In step S40, a layer of TFB is spin-coated on the upper surface of the quantum dot light-emitting layer 400 and annealed at 120 degrees for 20 minutes to obtain the hole transport layer 300. TFB is a conductive polymer and a commonly used material for hole transport layer 300.

[0082] In step S50, the driving circuit substrate 100, after the electron transport layer 500, quantum dot light-emitting layer 400, and hole transport layer 300 have been deposited, is placed on the laser direct writing stage, and a preset pattern is imported into the device. Figure 5 The laser irradiation path shown uses a 405nm continuous wave laser to irradiate the hole transport layer 300, damaging and degrading the hole transport layer 300 in the irradiated area to obtain an insulating current blocking portion 310. The non-irradiated area remains unchanged and allows current to pass through, forming hole pixel units 320 in the hole transport layer 300. Figure 5 The current blocking portion 310 and the hole pixel unit 320 shown are arranged in an array on the hole transport layer 300 with staggered intervals.

[0083] In step S60, HATCN is prepared by thermal evaporation to obtain hole injection layer 200.

[0084] In step S70, Al is finally deposited on the upper surface of the hole injection layer 200 as the top electrode layer 600 to complete the fabrication of the inverted light-emitting device 10.

[0085] It is important to understand that laser irradiation can occur on the upper surface of any layer structure deposited after the hole transport layer 300 is deposited. The intensity or time required for laser irradiation varies depending on the deposited structure, in order to form staggered and arrayed current blocking portions 310 and hole pixel units 320 on the hole transport layer 300. Therefore, the laser irradiation steps include: before laser irradiation, the target deposition structure needs to be determined according to the actual requirements, and the target layer structure is deposited layer by layer on one side of the driving circuit substrate 100 after the hole transport layer 300; then, the preset pattern is imported into the device, and laser irradiation is used to destroy and degrade the layer structure on one side of the upper surface of the target layer structure, forming insulating current blocking portions 310. The non-laser-irradiated areas remain unchanged, forming hole pixel units 320 in the hole transport layer 300. It should be noted that the layer structure penetrated by the laser is not limited here, but it must at least penetrate to the hole transport layer 300 to form hole pixel units.

[0086] In the fabrication process of the upright or inverted light-emitting device 10, the fabrication of the quantum dot light-emitting layer 400 includes two cases: monochromatic light emission and color-emitting quantum dot light-emitting layer 400. Among them, monochromatic light-emitting device 10 can be obtained by spin-coating monochromatic quantum dots as quantum dot light-emitting layer 400 in a glove box.

[0087] The specific steps for depositing the color-emitting (RGB three-color emission) quantum dot light-emitting layer 400 are as follows: Quantum dots suitable for UV cross-linking and curing are spin-coated onto the upper surface of the previously deposited hierarchical structure in a glove box. A patterned quantum dot light-emitting layer 400 is formed using photolithography, laser direct writing, or electron beam exposure. This step is repeated to pattern quantum dots of two other colors, forming a full-color quantum dot pixel layer as the quantum dot light-emitting layer 400. Specifically, photolithography allows quantum dots of different colors to be fabricated in different pixel areas to form the quantum dot pixel layer. The different colors of quantum dots are spin-coated in stages: first, one color of quantum dots is spin-coated, then photolithography and development are performed, and then this process is repeated. The pattern of the quantum dot light-emitting layer 400 is the same as that of the hole transport layer 300, so each light-emitting pixel unit 410 is aligned with a hole pixel unit. In full-color displays, the pixel size of the hole transport layer 300 is slightly smaller than the pixel size of the quantum dot light-emitting layer 400. After the quantum dot light-emitting layer 400 is patterned, it forms multiple spaced and arrayed light-emitting pixel units 410, and any three adjacent light-emitting pixel units 410 are arranged in an RGB array, so that the quantum dot light-emitting layer 400 can emit color light, thereby realizing the color light emission of the light-emitting device 10.

[0088] This invention provides a patterned quantum dot light-emitting device 10 and its fabrication method. On one hand, by irradiating the hole transport layer 300 with a laser, regions with different conductivity can be formed on the hole transport layer 300, forming hole pixel units 320. This eliminates the need for patterning the quantum dot light-emitting layer 400, allowing direct formation of a monochromatic patterned quantum dot light-emitting device 10. This solution only requires simple laser irradiation during the deposition of the light-emitting layer structure to complete the fabrication of the desired patterned quantum dot light-emitting device 10, greatly simplifying the fabrication process and reducing damage to the quantum dots in the quantum dot light-emitting layer 400, thereby achieving high-resolution patterning. On the other hand, for a full-color patterned quantum dot light-emitting device 10, laser irradiation oxidizes and degrades the hole transport layer 300, forming a current-blocking portion 310 in the irradiated area. This blocks electron-hole recombination, reduces device leakage, and thus improves the photoelectric performance of the light-emitting device 10.

[0089] Although the invention has been described with reference to several typical embodiments, it should be understood that the terminology used is illustrative and exemplary, and not restrictive. Since the invention can be embodied in many forms without departing from the spirit or essence of the invention, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope defined by the appended claims. Therefore, all variations and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A method for fabricating a patterned quantum dot light-emitting device, characterized in that, It includes the following steps: Prepare the drive circuit board and clean and pre-treat it; A hole injection layer, a hole transport layer, a quantum dot light-emitting layer, an electron transport layer, and an electrode layer are sequentially deposited on one side of the driving circuit substrate to obtain an upright quantum dot display device; In the process of fabricating the upright quantum dot display device, at least the hole transport layer is irradiated with a laser to form staggered and arrayed current blocking parts and hole pixel units on the hole transport layer. The current blocking parts are insulating regions, and the hole pixel units allow current to pass through, thereby making the hole transport layer pixelated to prepare an upright patterned quantum dot light-emitting device.

2. A method for fabricating a patterned quantum dot light-emitting device, characterized in that, It includes the following steps: Prepare the drive circuit board and clean and pre-treat it; An inverted quantum dot display device is obtained by sequentially depositing an electron transport layer, a quantum dot light-emitting layer, a hole transport layer, a hole injection layer and an electrode layer on one side of the driving circuit substrate. In the process of fabricating the inverted quantum dot display device, at least the hole transport layer is irradiated with a laser to form staggered and arrayed current blocking parts and hole pixel units on the hole transport layer. The current blocking parts are insulating regions, and the hole pixel units allow current to pass through, thereby pixelating the hole transport layer to prepare an inverted patterned quantum dot light-emitting device.

3. The method for fabricating a patterned quantum dot light-emitting device according to claim 1 or 2, characterized in that, The steps of laser irradiation include: The target hierarchical structure is deposited layer by layer on one side of the driving circuit substrate, and the target hierarchical structure is deposited and formed after the hole transport layer; A preset pattern is imported into the device, and a laser is used to irradiate one side of the upper surface of the target hierarchical structure to destroy and degrade the hierarchical structure in the irradiated area to form the current blocking part. The area not irradiated by the laser remains unchanged and forms the hole pixel unit in the hole transport layer.

4. The method for fabricating a patterned quantum dot light-emitting device according to claim 1 or 2, characterized in that, The step of depositing the quantum dot light-emitting layer includes: spin-coating monochromatic quantum dots as the quantum dot light-emitting layer in a glove box to obtain a monochromatic patterned quantum dot light-emitting device.

5. The method for fabricating a patterned quantum dot light-emitting device according to claim 1 or 2, characterized in that, The steps for depositing a quantum dot light-emitting layer include: spin-coating quantum dots that can be used for UV cross-linking and curing in a glove box, forming a patterned quantum dot layer by photolithography; repeating the spin-coating and photolithography operations to pattern quantum dots of two other colors to form a full-color quantum dot pixel layer as the quantum dot light-emitting layer, thereby obtaining a full-color patterned quantum dot light-emitting device.

6. The method for fabricating a patterned quantum dot light-emitting device according to claim 5, characterized in that, The quantum dot light-emitting layer forms multiple spaced and arrayed light-emitting pixel units, with each light-emitting pixel unit being paired with a hole pixel unit.

7. A patterned quantum dot light-emitting device prepared by any one of claims 1 to 6, characterized in that, include: Drive circuit board; A light-emitting layer structure, comprising a hole injection layer, a hole transport layer, a quantum dot light-emitting layer and an electron transport layer stacked sequentially, wherein the hole injection layer or the electron transport layer is stacked on one side of the driving circuit substrate; An electrode layer is stacked on the side of the light-emitting layer structure opposite to the driving circuit substrate; The patterned quantum dot light-emitting device further includes staggered and arrayed current blocking portions and hole pixel units, wherein the current blocking portions are insulating regions and the hole pixel units allow current to pass through; in the direction of stacking of the light-emitting layer structure, the current blocking portions and the hole pixel units extend at least to opposite sides of the hole transport layer.

8. The patterned quantum dot light-emitting device according to claim 7, characterized in that, The quantum dot light-emitting layer emits monochromatic light.

9. The patterned quantum dot light-emitting device according to claim 7, characterized in that, The quantum dot light-emitting layer emits colored light and includes multiple spaced and arrayed light-emitting pixel units. The multiple light-emitting pixel units can emit three colors of light, and any three adjacent light-emitting pixel units are arranged in an RGB array.

10. The patterned quantum dot light-emitting device according to claim 9, characterized in that, Along the direction of stacking the light-emitting hierarchy, the light-emitting pixel unit and the hole pixel unit are aligned one-to-one; And / or, the gap between two adjacent light-emitting pixel units is partially filled by the electron transport layer.

Images