Patterned quantum dot light-emitting device and preparation method thereof

Abstract

The invention relates to a patterned quantum dot light-emitting device and a preparation method thereof, the patterned quantum dot light-emitting device comprises a driving circuit substrate, a light-emitting hierarchical structure and an electrode layer, the light-emitting hierarchical structure comprises a hole injection layer, a hole transport layer, a quantum dot light-emitting layer and an electron transport layer which are stacked in sequence, the electrode layer is disposed between the driving circuit substrate and the electrode layer. In the preparation process of the patterned quantum dot, laser irradiation with different intensities is performed on a hole transport layer and different hierarchical structures after the hole transport layer (deposition sequence) in the process of depositing the hierarchical structures, and the laser irradiates the hole transport layer, so that current blocking parts and pixel units which are arranged in a staggered and array manner are formed in the hole transport layer; pixel processing is carried out on the hole transport layer so as to complete the preparation process of the whole patterned quantum dot light-emitting device. According to the invention, the process complexity of the patterned quantum dot light-emitting device can be reduced, and the damage to the quantum dots in the quantum dot light-emitting layer is reduced, so that high-resolution patterning is realized.

Description

Technical Field

[0001] The present invention relates to the field of quantum dot technology, and in particular to a patterned quantum dot light-emitting device and a preparation method thereof. Background Art

[0002] Quantum dot light-emitting diodes (QLEDs) have attracted widespread attention due to their remarkable characteristics such as 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. At present, research on QLED pixelation mainly focuses on the emission layer (EML), and the methods used include transfer, photolithography, and selective electrophoretic deposition. Among them, transfer technology is prone to damage the quantum dot layer during the transfer process; the chemicals and ultraviolet light used in the photolithography process in photolithography technology may cause damage to the quantum dot material; selective electrophoretic deposition requires the surface of the quantum dots to be treated, causing damage to the quantum dot layer. Therefore, the existing technology will more or less damage the quantum dot layer or quantum dot material in the corresponding process, reducing the stability and luminous efficiency of the quantum dots, thereby affecting the optical and electrical properties of the quantum dot light-emitting diode. In addition, the uniformity and control difficulty of the existing process are relatively large, and it is not easy to be applied to large-scale production. Moreover, in areas without quantum dots after quantum dot patterning, the hole transport layer (HTL) will be in direct contact with the electron transport layer (ETL), which may create the risk of a low-resistance current leakage path, resulting in a significant reduction in device performance. Summary of the invention

[0003] The present invention provides a patterned quantum dot light-emitting device and a method for preparing the same, so as to solve the technical problem that in areas without quantum dots after quantum dot patterning, the hole transport layer will be in direct contact with the electron transport layer, which may generate the risk of a low-resistance current leakage path, resulting in a significant reduction in device performance.

[0004] First aspect

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

[0006] Prepare the drive circuit substrate 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 a normal quantum dot display device;

[0008] In the process of preparing the upright quantum dot display device, at least the hole transport layer is irradiated with laser to form staggered and arrayed current blocking parts and hole pixel units in the hole transport layer, wherein the current blocking part is an insulating area and the hole pixel unit allows current to pass through, so that the hole transport layer is pixelated to prepare an upright patterned quantum dot light-emitting device.

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

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

[0011] An electron transport layer, a quantum dot light-emitting layer, a hole transport layer, a hole injection layer and an electrode layer are sequentially deposited on one side of the driving circuit substrate to obtain an inverted quantum dot display device;

[0012] In the process of preparing the inverted quantum dot display device, at least the hole transport layer is irradiated with laser to form staggered and arrayed current blocking parts and hole pixel units in the hole transport layer, wherein the current blocking part is an insulating area and the hole pixel unit allows current to pass through, so that the hole transport layer is pixelated to prepare an inverted patterned quantum dot light-emitting device.

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

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

[0015] A preset pattern is introduced 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 non-laser irradiated area remains intact and the hole pixel unit is formed in the hole transport layer.

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

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

[0018] In one embodiment, the quantum dot light-emitting layer forms a plurality of light-emitting pixel units that are spaced apart and arranged in an array, and each of the light-emitting pixel units is aligned one by one with the hole pixel units.

[0019] Second aspect

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

[0021] Driving circuit substrate;

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

[0023] An electrode layer, stacked and arranged on a side of the light-emitting hierarchical structure away from the driving circuit substrate;

[0024] Among them, the patterned quantum dot light-emitting device also includes a current blocking portion and a hole pixel unit that are staggered and arranged in an array, the current blocking portion is an insulating area, and the hole pixel unit allows current to pass through; in the direction along the stacking of the light-emitting hierarchical structure, the current blocking portion and the hole pixel unit extend to at least the 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 the quantum dot light-emitting layer includes a plurality of light-emitting pixel units that are spaced apart and arranged in an array. The plurality of light-emitting pixel units can emit light of three colors, and any three adjacent light-emitting pixel units are arranged in an RGB array.

[0027] In one of the embodiments, along the stacking direction of the light-emitting hierarchical structure, the light-emitting pixel units and the cavity pixel units are aligned one by one;

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

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

[0030] The embodiment of the present invention provides a patterned quantum dot light-emitting device and a method for preparing the same. On the one hand, by irradiating the hole transport layer with a laser, regions with different conductive properties can be formed on the hole transport layer to form hole pixel units. The quantum dot light-emitting layer does not need to be patterned, and a monochrome patterned quantum dot light-emitting device can be directly formed. This solution only requires simple laser irradiation during the deposition of the light-emitting hierarchical structure to complete the preparation of the required patterned quantum dot light-emitting device, which greatly simplifies the preparation process and simultaneously reduces the damage to the quantum dots in the quantum dot light-emitting layer, thereby achieving high-resolution patterning. On the other hand, for full-color patterned quantum dot light-emitting devices, the hole transport layer is oxidatively degraded by laser irradiation to form a current blocking portion in the irradiated area to block the recombination of electrons and holes, reduce device leakage, and thus improve the photoelectric performance of the patterned quantum dot light-emitting device. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0032] Figure 1 A schematic diagram of the hierarchical structure of the upright patterned quantum dot light-emitting device of the present application;

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

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

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

[0036] Figure 5 The figure is a flow chart for preparing a positive patterned quantum dot light-emitting device;

[0037] Figure 6 The flowchart for the preparation of inverted patterned quantum dot light-emitting devices.

[0038] The following are the descriptions of the reference numerals:

[0039] 10. Patterned quantum dot light-emitting device; 100. Driving circuit substrate; 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 DESCRIPTION

[0040] Typical embodiments that embody 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 changes in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations therein are essentially used for illustration purposes rather than for limiting the present invention.

[0041] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0042] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "setting", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0043] refer to Figure 1 , the present application provides a patterned quantum dot light-emitting device 10 (hereinafter referred to as: light-emitting device 10), which performs pixelation by laser irradiation of the hole transport layer 300 to achieve patterning of the hole transport layer 300, thereby achieving patterning of the light-emitting device 10. Here, the laser can selectively oxidize and degrade part of the structure of the hole transport layer 300, reduce the conductivity of the laser irradiated area, and the area not irradiated by the laser is not affected. This method makes pixelation do not require complex masks or multi-step processes. It should be understood that in the present application, laser irradiation is only for photolithography of the hole transport layer 300 to achieve patterning. In other embodiments, ultraviolet light can also be used to photolithograph the hole transport layer 300. Therefore, in the present application, there is no limitation on the light used for photolithography of the hole transport layer 300.

[0044] Combined with reference Figure 1 and Figure 2According to the order and performance of the hierarchical structure, the light emitting device 10 includes an upright light emitting device 10 and an inverted light emitting device 10 . Figure 1 As shown, 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 which are stacked layer by layer. Figure 2 As shown, the inverted light-emitting device 10 is to exchange the positions of the driving circuit substrate 100 and the electrode layer 600. 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. Among them, the hole injection layer 200, the hole transport layer 300, the quantum dot light-emitting layer 400, and the electron transport layer 500 constitute a light-emitting hierarchical structure, and the light-emitting hierarchical structure is located between the driving circuit substrate 100 and the electrode layer 600, that is, the electrode layer 600 is stacked and arranged on the side of the light-emitting hierarchical structure away from the driving circuit substrate 100. It should be noted that the driving circuit board 100 is provided with an electrode structure (anode structure and cathode structure) with opposite polarity to the electrode layer 600, so the light-emitting hierarchical structure is stacked and arranged between the cathode and the anode. For the upright light-emitting device 10, an anode structure is provided on the driving circuit board 100, 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 substrate 100; for the inverted light-emitting device 10, a cathode structure is provided on the driving circuit board 100, 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 substrate 100.

[0045] In addition, combined with reference Figure 1 and Figure 3 , the hole transport layer 300 of the light-emitting device 10 also includes a current blocking portion 310 and a hole pixel unit 320 that are staggered and arranged in an array. The current blocking portion 310 is an insulating region formed by reducing the conductivity of a portion of the hole transport layer 300 after being irradiated by laser, and can block the passage of current; the hole pixel unit 320 is a non-insulating region formed by retaining the original state of a portion of the hole transport layer 300 that is not irradiated by laser, and can allow current to pass. In one embodiment, the laser only irradiates the hole transport layer 300, and the current blocking portion 310 and the hole pixel unit 320 are just formed in the hole transport layer 300, that is, in the direction along the stacking of the light-emitting hierarchical structure, the current blocking portion 310 and the hole pixel unit 320 extend to opposite sides of the hole transport layer 300.

[0046] It should be understood that in the present application, under the premise that the time and intensity of laser irradiation are sufficient, in order to achieve patterning of the hole transport layer 300, laser irradiation can occur on the upper surface of any hierarchical structure deposited after the hole transport layer 300 is deposited and thereafter. In the upright light-emitting device 10, 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, 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 the hole transport layer 300 from top to bottom to form an interlaced and arrayed current blocking portion 310 and a hole pixel unit 320 in the hole transport layer 300.

[0047] The present solution will be further described below by taking the example of laser irradiation only on the hole transport layer 300 in the upright light-emitting device 10 .

[0048] Combined with reference Figure 1 and Figure 4 According to the composition and light-emitting conditions of the quantum dot light-emitting layer 400, the light-emitting device 10 of the present application includes a monochrome light-emitting device 10 ( Figure 1 As shown) and full-color light emitting device 10 ( Figure 4 shown). Figure 1 It is illustrated that in a monochrome light-emitting device 10, the quantum dot light-emitting layer 400 includes only light-emitting pixels of one color, and the quantum dot light-emitting layer 400 emits monochrome light; Figure 4 It is illustrated that in a full-color light-emitting device 10, the quantum dot light-emitting layer 400 includes a plurality of light-emitting pixel units 410 of different colors that are spaced apart and arranged in an array. The plurality of 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 colored light emission to achieve full-color display of the light-emitting device 10.

[0049] Continue to refer Figure 4In this embodiment, in the color light-emitting device 10, along the stacking direction of the light-emitting hierarchical structure, the gap width dimension between two adjacent light-emitting pixel units 410 is not greater than the width dimension of the current blocking portion 310, 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, so the light-emitting pixel unit 410 is aligned one by one with the hole pixel unit 320. 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 with other materials that can transport electrons.

[0050] In the present application, the hierarchical structure material selection in the light emitting device 10 is as follows: the hole injection layer 200 includes but is not limited to high conductivity PEDOT:PSS, NiO X 、MoO 3 and other materials; the hole transport layer 300 material can adopt conventional hole transport layer 300 materials in the art, including but not limited to TFB and PVK, poly-TPD, PF8Cz and other materials; the material of the quantum dot light-emitting layer 400 can be a II-VI group compound semiconductor, such as CdS, CdSe, CdS / ZnS, CdSe / ZnS or CdSe / CdS / ZnS, etc., or a III-V group compound semiconductor, such as InP, etc., and can also include perovskite quantum dot materials, organic inorganic perovskite quantum dot materials, and all-inorganic perovskite quantum dot materials; the electron transport layer 500 material can adopt conventional electron transport materials in the art, including but not limited to ZnO and ZnMgO and other materials; 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] In this application, the lasers used include continuous lasers, nanosecond, picosecond and femtosecond pulse lasers. The laser wavelength range is between 300nm and 800nm, the power range is between 0.01mW and 100W, and the laser energy density is between 5 and 10000kJ / cm 2 , the spot size of the laser is 0.5-10 μm. It should be noted that in the present application, since the type of laser is not limited, the relevant operating parameters of the laser irradiation are not limited.

[0052] In the second aspect, the present application also provides a method for preparing a patterned quantum dot light-emitting device 10 (hereinafter referred to as: light-emitting device 10), which mainly includes the steps of sequentially stacking deposition and laser irradiation. Since laser irradiation can occur on one or more hierarchical structures, in order to clearly describe the preparation process, the laser irradiation only occurs in the hole transport layer 300 as an example for detailed description. In addition, the light-emitting device 10 includes an upright light-emitting device 10 and an inverted light-emitting device 10. The preparation processes of the upright device and the inverted device are as follows.

[0053] Combined with reference Figure 1 and Figure 5 The method for preparing the upright light emitting device 10 comprises the following steps:

[0054] S10: preparing a driving circuit substrate 100;

[0055] S20: depositing a hole injection layer 200;

[0056] S30: depositing a hole transport layer 300;

[0057] S40: irradiating the hole transport layer 300 with laser;

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

[0059] S60: depositing an electron transport layer 500;

[0060] S70: depositing an electrode layer 600;

[0061] In the above, through steps S20, S30, S50, S60, and S70, 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 are sequentially deposited on one side of the driving circuit substrate 100 to obtain an upright quantum dot display device (not pixelated). In the process of obtaining the upright quantum dot display device, at least the hole transport layer 300 is irradiated with a laser to form a current blocking portion 310 and a hole pixel unit 320 that are staggered and arranged in an array on the hole transport layer 300. The current blocking portion 310 is an insulating area, and the hole pixel unit 320 allows current to pass through, so that the hole transport layer 300 is pixelated to prepare an upright light-emitting device 10.

[0062] Specifically, in step S10, the drive circuit substrate 100 is prepared and cleaned and pre-treated. The substrate is first ultrasonically cleaned with acetone, ethanol and deionized water for 15 minutes, then placed in an oven for drying for 30 minutes, and then treated with oxygen plasma or UV-ozone for 5 minutes. It should be noted that in the above steps, the ultrasonic cleaning and drying of the substrate are to clean and remove impurities, and the substrate is treated with oxygen plasma or UV-ozone 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 driving circuit substrate 100 in air and annealed at 130 degrees in air for 20 minutes to obtain a hole injection layer 200, wherein PEDOT:PSS is an aqueous solution of a high molecular polymer with high conductivity.

[0064] In step S30, the driving circuit substrate 100 is placed in a glove box, 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 annealed at 120 degrees for 20 minutes to obtain a hole transport layer 300. TFB is a conductive polymer and a commonly used material for the hole transport layer 300.

[0065] In step S40, the driving circuit substrate 100 on which the hole injection layer 200 and the hole transport layer 300 are deposited is placed on a laser direct writing platform, and a preset pattern is introduced into the device. Figure 5 The laser irradiation path shown in FIG. 1 is to use a 405 nm continuous wave laser to irradiate the hole transport layer 300, destroy and degrade the hole transport layer 300 in the irradiated area to obtain an insulating current blocking portion 310, and keep the non-irradiated area as it is for current to pass through, so as to form a hole pixel unit 320 in the hole transport layer 300, as shown in FIG. Figure 3 The current blocking parts 310 and the hole pixel units 320 are arranged in an array and staggered at intervals on the hole transport layer 300. 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 on the upper surface of the hole transport layer 300 after laser irradiation in an inert atmosphere of a glove box as a quantum dot light-emitting layer 400, where the quantum dot light-emitting layer 400 can be monochromatic or colorful. It should be noted that when the quantum dot light-emitting layer 400 is monochromatic quantum dots, in other embodiments, monochromatic quantum dots can also be prepared by inkjet printing, nanoimprinting, scraping, etc. That is, in this application, the method for preparing monochromatic quantum dots is not limited.

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

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

[0069] Combined with reference Figure 2 and Figure 6 The method for preparing the inverted light emitting device 10 comprises the following steps:

[0070] S10: preparing the driving circuit substrate 100;

[0071] S20: depositing an electron transport layer 500;

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

[0073] S40: Depositing a hole transport layer 300

[0074] S50: irradiating the hole transport layer 300 with laser;

[0075] S60: depositing a hole injection layer 200;

[0076] S70 : depositing an electrode layer 600 .

[0077] In the above, through 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 sequentially deposited on one side of a driving circuit substrate 100 to obtain an inverted quantum dot display device (not pixelated). In the process of preparing the inverted quantum dot display device, at least the hole transport layer 300 is irradiated with a laser to form a current blocking portion 310 and a hole pixel unit 320 that are staggered and arranged in an array on the hole transport layer 300. The current blocking portion 310 is an insulating area, and the hole pixel unit 320 allows current to pass through, so that the hole transport layer 300 is pixelated to prepare an inverted light-emitting device 10.

[0078] Specifically, in step S10, a driving circuit substrate 100 is prepared and cleaned and pretreated to obtain a driving circuit substrate. The substrate is first ultrasonically cleaned with acetone, ethanol and deionized water for 15 minutes, then placed in an oven for drying for 30 minutes, and then 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 to clean and remove impurities, and oxygen plasma or UV-ozone treatment of the substrate is to change the wettability of the substrate.

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

[0080] In step S30, a quantum dot layer is spin-coated on the upper surface of the electron transport layer 500 in an inert atmosphere of a glove box as a quantum dot light-emitting layer 400. The quantum dot light-emitting layer 400 here can emit either 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 the hole transport layer 300 .

[0082] In step S50, the driving circuit substrate 100 on which the electron transport layer 500, the quantum dot light-emitting layer 400, and the hole transport layer 300 are deposited is placed on a laser direct writing platform, and a preset pattern is introduced into the device. Figure 5 The laser irradiation path shown in FIG. 1 is to use a 405 nm continuous wave laser to irradiate the hole transport layer 300, destroy and degrade the hole transport layer 300 in the irradiated area to obtain an insulating current blocking portion 310, and keep the non-irradiated area as it is for current to pass through, so as to form a hole pixel unit 320 in the hole transport layer 300, as shown in FIG. Figure 5 The current blocking portions 310 and the hole pixel units 320 are arranged in an array and staggered at intervals on the hole transport layer 300 .

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

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

[0085] It should be understood that laser irradiation can occur on the upper surface of any hierarchical structure deposited after and after the hole transport layer 300 is deposited, and the intensity or time required for laser irradiation of different deposition structures is different, so as to form the current blocking parts 310 and the hole pixel units 320 arranged in an array and staggered at intervals on the hole transport layer 300. Therefore, the steps of laser irradiation include: before laser irradiation, it is necessary to determine the target deposition structure according to the actual demand, and deposit the target deposition structure layer by layer on one side of the driving circuit substrate 100, and the target deposition structure is deposited after the hole transport layer 300; then the preset pattern is introduced into the device, and the hierarchical structure of the irradiated area is destroyed and degraded to form an insulating current blocking part 310 by laser irradiation on one side of the upper surface of the target hierarchical structure, and the non-laser irradiated area remains intact to form the hole pixel unit 320 in the hole transport layer 300. It should be noted that here, the hierarchical structure penetrated by the laser is not limited, but at least penetrates to the hole transport layer 300 to form a hole pixel unit.

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

[0087] The specific steps of depositing the quantum dot light-emitting layer 400 for color light emission (RGB three-color light emission) are as follows: spin-coating quantum dots that can be used for UV cross-linking curing on the upper surface of the previously deposited hierarchical structure in a glove box, using photolithography, laser direct writing or electron beam exposure to form a patterned quantum dot light-emitting layer 400, and then repeating this step to pattern the quantum dots of the other two colors to form 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 prepared in different pixel areas. This is to form a quantum dot pixel layer. Quantum dots of different colors are deposited by spin coating in batches. First, one color of quantum dots is spin-coated, then photolithography, development, and then this step 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 the hole pixel unit one by one. In a full-color display, the pixel size of the hole transport layer 300 will be slightly smaller than the pixel size of the quantum dot light-emitting layer 400. After patterning, the quantum dot light-emitting layer 400 forms a plurality of spaced and array-arranged 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 colored light, thereby realizing colored light emission of the light-emitting device 10 .

[0088] The embodiment of the present invention provides a patterned quantum dot light-emitting device 10 and a preparation method thereof. On the one hand, by irradiating the hole transport layer 300 with a laser, a region with different conductive properties can be formed on the hole transport layer 300 to form a hole pixel unit 320. The quantum dot light-emitting layer 400 does not need to be patterned, and a monochrome patterned quantum dot light-emitting device 10 can be directly formed. This solution only requires simple laser irradiation during the deposition of the light-emitting hierarchical structure to complete the preparation of the required patterned quantum dot light-emitting device 10, which greatly simplifies the preparation process and reduces the damage to the quantum dots in the quantum dot light-emitting layer 400, thereby achieving high-resolution patterning. On the other hand, for the full-color patterned quantum dot light-emitting device 10, the hole transport layer 300 is oxidatively degraded by laser irradiation, and a current blocking portion 310 is formed in the irradiated area to block the recombination of electrons and holes, reduce device leakage, and thus improve the photoelectric performance of the light-emitting device 10.

[0089] Although the present invention has been described with reference to several typical embodiments, it should be understood that the terms used are illustrative and exemplary, rather than restrictive. Since the present invention can be embodied in a variety of 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, so all changes and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A method for preparing a patterned quantum dot light-emitting device, characterized in that: The steps include: Prepare the drive circuit substrate 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 a normal quantum dot display device; In the process of preparing the upright quantum dot display device, at least the hole transport layer is irradiated with laser to form staggered and arrayed current blocking parts and hole pixel units in the hole transport layer, wherein the current blocking part is an insulating area and the hole pixel unit allows current to pass through, so that the hole transport layer is pixelated to prepare an upright patterned quantum dot light-emitting device.

2. A method for preparing a patterned quantum dot light-emitting device, characterized in that: The steps include: Prepare the drive circuit substrate and clean and pre-treat it; An electron transport layer, a quantum dot light-emitting layer, a hole transport layer, a hole injection layer and an electrode layer are sequentially deposited on one side of the driving circuit substrate to obtain an inverted quantum dot display device; In the process of preparing the inverted quantum dot display device, at least the hole transport layer is irradiated with laser to form staggered and arrayed current blocking parts and hole pixel units in the hole transport layer, wherein the current blocking part is an insulating area and the hole pixel unit allows current to pass through, so that the hole transport layer is pixelated to prepare an inverted patterned quantum dot light-emitting device.

3. The method for preparing a patterned quantum dot light-emitting device according to claim 1 or 2, characterized in that: The steps of laser irradiation include: Depositing layer by layer on one side of the driving circuit substrate to a target hierarchical structure, wherein the target hierarchical structure is deposited and formed after the hole transport layer; A preset pattern is introduced 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 non-laser irradiated area remains intact and the hole pixel unit is formed in the hole transport layer.

4. The method for preparing a patterned quantum dot light-emitting device according to claim 1 or 2, characterized in that: The step of depositing and forming 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 preparing a patterned quantum dot light-emitting device according to claim 1 or 2, characterized in that: The steps of 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, and forming a patterned quantum dot layer by photolithography; repeating the spin coating and photolithography operations, patterning the quantum dots of the other two colors, and forming a full-color quantum dot pixel layer as the quantum dot light-emitting layer to obtain a full-color patterned quantum dot light-emitting device.

6. The method for preparing a patterned quantum dot light-emitting device according to claim 5, characterized in that: The quantum dot light-emitting layer forms a plurality of light-emitting pixel units which are spaced apart and arranged in an array, and each of the light-emitting pixel units is aligned one by one with the hole pixel units.

7. A patterned quantum dot light-emitting device prepared by the preparation method according to any one of claims 1 to 6, characterized in that: include: Driving circuit substrate; A light-emitting hierarchical structure, wherein the light-emitting hierarchical structure comprises a hole injection layer, a hole transport layer, a quantum dot light-emitting layer and an electron transport layer stacked in sequence, wherein the hole injection layer or the electron transport layer is stacked and arranged on one side of the driving circuit substrate; An electrode layer, stacked and arranged on a side of the light-emitting hierarchical structure away from the driving circuit substrate; Among them, the patterned quantum dot light-emitting device also includes a current blocking portion and a hole pixel unit that are staggered and arranged in an array, the current blocking portion is an insulating area, and the hole pixel unit allows current to pass through; in the direction along the stacking of the light-emitting hierarchical structure, the current blocking portion and the hole pixel unit extend to at least the 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. The quantum dot light-emitting layer includes a plurality of light-emitting pixel units that are spaced apart and arranged in an array. The plurality of light-emitting pixel units can emit light of three colors, 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: In the direction along which the light-emitting hierarchical structure is stacked, the light-emitting pixel units are aligned one by one with the cavity pixel units; And / or, a gap between two adjacent light-emitting pixel units is partially filled with the electron transport layer.

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