Preparation method of full-color LED device and full-color LED device

Abstract

The invention discloses a preparation method of a full-color LED device and the full-color LED device. The preparation method comprises the following steps: preparing a self-assembly red light quantum dot solution and a self-assembly green light quantum dot solution; preparing a single blue display module, and arranging a first dielectric layer on the top layer of the display module; setting a red light quantum dot gathering area on the first dielectric layer through a photoetching process; forming a red light self-assembly quantum layer in a red light quantum dot aggregation area through a self-assembly red light quantum dot solution; a second dielectric layer is arranged on the red light self-assembly quantum layer; setting a green light quantum dot gathering area on the first dielectric layer through a photoetching process; forming a green light self-assembled quantum layer in a green light quantum dot gathering area through a self-assembled green light quantum dot solution; a third dielectric layer is arranged on the second dielectric layer and the green light self-assembly quantum layer; and setting a plurality of window positions on the third dielectric layer through a photoetching process to form the full-color LED device.

Description

Technical Field

[0001] The present invention relates to the technical field of LED devices, and particularly relates to a preparation method and a full-color LED device of a full-color LED device. Background Art

[0002] Micro light-emitting diodes (Micro LEDs) are one of the ideal building blocks for current wearable display devices. Since micro light-emitting diodes need to meet high resolution and good full-color display effects, current full-color micro LED devices mainly achieve color conversion by preparing patterned quantum dots on a blue light module. Due to the small size of micro light-emitting diodes, the coating and binding performance of quantum dots assembled on small-sized devices is weak, that is, the binding stability between the quantum layer and the blue light module is insufficient, and light leakage is likely to occur, affecting the color conversion effect and thus the display effect of the full-color LED device. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art. The present invention provides a preparation method and a full-color LED device of a full-color LED device. By setting a self-assembled red quantum dot solution and a self-assembled green quantum dot solution, the self-assembly binding ability of the quantum layer on the device is improved, the risk of light leakage can be effectively reduced, and the color conversion effect and light extraction efficiency of the full-color LED device are ensured.

[0004] The present invention provides a preparation method of a full-color LED device, and the preparation method includes:

[0005] Preparing a self-assembled red quantum dot solution and a self-assembled green quantum dot solution;

[0006] Preparing a single blue display module and setting a first dielectric layer on the top layer of the display module;

[0007] Setting a red quantum dot aggregation region on the first dielectric layer through a photolithography process;

[0008] Forming a red self-assembled quantum layer in the red quantum dot aggregation region through the self-assembled red quantum dot solution;

[0009] A second dielectric layer is provided on the red self-assembled quantum layer;

[0010] Setting a green quantum dot aggregation region on the first dielectric layer through a photolithography process;

[0011] Forming a green self-assembled quantum layer in the green quantum dot aggregation region through the self-assembled green quantum dot solution;

[0012] A third dielectric layer is provided on the second dielectric layer and the green self-assembled quantum layer;

[0013] Several window positions are set on the third dielectric layer through a lithography process to form a full-color LED device.

[0014] Further, the preparation of the self-assembled red quantum dot solution includes:

[0015] Based on Cs2CO3, oleic acid, and octadecene, a cesium oleate precursor is prepared by mixing.

[0016] Based on PbI2 and octadecene, a first mixed solution is formed. Under nitrogen protection, oleic acid and oleylamine are injected into the first mixed solution to obtain a lead iodide precursor.

[0017] The cesium oleate precursor is quickly injected into the heated lead iodide precursor after heating to obtain a CsPbI3 crude solution.

[0018] After purifying the CsPbI3 crude solution, a CsPbI3 perovskite quantum dot solution is obtained.

[0019] The CsPbI3 perovskite quantum dot solution is subjected to a thiol ligand exchange to obtain a thiol self-assembled CsPbI3 red quantum dot solution.

[0020] Further, the preparation of the self-assembled green quantum dot solution includes:

[0021] Based on indium chloride and oleic acid, indium oleate is prepared. Combining a triphosphorus solution and an octadecene solution to prepare an InP core solution.

[0022] Zn(St)2 and an S precursor are alternately added dropwise to the InP core solution to obtain an InP / ZnS quantum dot crude solution.

[0023] Based on an ethyl acetate solution, the InP / ZnS quantum dot crude solution is purified to obtain an InP / ZnS quantum dot solution.

[0024] The InP / ZnS quantum dot solution is subjected to a citric acid ligand exchange treatment to obtain a self-assembled green quantum dot solution.

[0025] Further, the step of subjecting the InP / ZnS quantum dot solution to a citric acid ligand exchange treatment to obtain a self-assembled green quantum dot solution includes:

[0026] The InP / ZnS quantum dot solution and citric acid are added to ethanol at a molar ratio of 1:1000. After ultrasonic treatment, NaOH is added to adjust the pH value to 9-10 to obtain a preliminary reaction solution.

[0027] The preliminary reaction solution is placed in a centrifuge for treatment. The rotation speed of the centrifuge is set to 8000 rpm, and the working time of the centrifuge is set to 10 min to obtain a separated solution.

[0028] Add ethanolamine to the separated solution to adjust the pH value to 7, obtaining a self-assembled green quantum dot solution.

[0029] Further, the step of setting the red quantum dot aggregation region on the first dielectric layer through a lithography process includes:

[0030] Evaporate and grow an ITO nano-film on the surface of the first dielectric layer by electron beam, and perform surface treatment on the ITO nano-film.

[0031] Perform lithography treatment on the surface of the ITO film after surface treatment to form a number of window positions, and expose the red quantum dot aggregation region on the ITO film based on the window positions.

[0032] Further, the step of forming a red self-assembled quantum layer in the red quantum dot aggregation region through the self-assembled red quantum dot solution includes:

[0033] Etch the wafer with a hydrofluoric acid solution, and perform a de-glue operation on the photoresist of the wafer.

[0034] Place the de-glued wafer in the self-assembled red quantum dot solution and soak it to obtain a first red quantum layer.

[0035] Rinse the first red quantum layer with ethyl acetate.

[0036] Place the rinsed wafer in the self-assembled red quantum dot solution and soak it to prepare a second red quantum layer on the surface of the first red quantum layer.

[0037] Further, the step of rinsing the first red quantum layer with ethyl acetate includes:

[0038] Rinse the first red quantum layer by spin coating method. Take 5 ml of ethyl acetate and perform dynamic spin coating on the surface of the wafer. Set the spin coating speed to 500 r / min and the spin coating time to 20 s, and perform surface treatment on the first red quantum layer based on the ethyl acetate.

[0039] Further, the step of forming a green self-assembled quantum layer in the green quantum dot aggregation region through the self-assembled green quantum dot solution includes:

[0040] Perform surface treatment on the wafer, activate the green quantum dot aggregation region on the surface of the wafer, and soak the wafer after surface treatment in the self-assembled green quantum dot solution. The green self-assembled quantum layer is formed by self-assembly of the green quantum dots in the self-assembled green quantum dot solution.

[0041] The present invention also provides a full-color LED device, which is prepared based on the preparation method of the full-color LED device. The full-color LED device includes:

[0042] A full-color LED device, a red self-assembled quantum layer and a green self-assembled quantum layer disposed on the blue light display module;

[0043] A metal reflective layer is disposed on the top of the full-color LED device, and a plurality of window structures are formed in the metal reflective layer. The full-color LED device forms a blue light output channel, a red light output channel and a green light output channel based on the plurality of window structures.

[0044] Further, the thickness of the metal reflective layer is 2 μm.

[0045] The present invention provides a preparation method and a full-color LED device. By adjusting the self-assembled red quantum dot solution and the self-assembled green quantum dot solution, surface treatment is performed on a single blue display module. The red self-assembled quantum layer is formed by soaking in the self-assembled red quantum dot solution, and the green self-assembled quantum layer is formed by soaking in the self-assembled green quantum dot solution, which can improve the self-assembly binding ability of the quantum layer on the device surface, thereby improving the structural connection stability of the full-color LED device, effectively reducing the risk of light leakage, and ensuring the light color conversion effect and light output efficiency of the full-color LED device. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0047] Figure 1 is a flowchart of a preparation method of a full-color LED device in an embodiment of the present invention;

[0048] Figure 2 is a structural schematic diagram of a single blue display module in an embodiment of the present invention;

[0049] Figure 3 is a structural schematic diagram of a first dielectric layer preparation state in an embodiment of the present invention;

[0050] Figure 4 is a structural schematic diagram of an ITO nano-film preparation state in an embodiment of the present invention;

[0051] Figure 5 is a structural schematic diagram of a red quantum dot aggregation region preparation state in an embodiment of the present invention;

[0052] Figure 6 is a flowchart of a preparation method of a red self-assembled quantum layer in an embodiment of the present invention;

[0053] Figure 7 Schematic diagram of the preparation state of the first red light quantum layer in the embodiment of the present invention;

[0054] Figure 8 Schematic diagram of the preparation state of the second red light quantum layer in the embodiment of the present invention;

[0055] Figure 9 Schematic diagram of the preparation state of the second dielectric layer in the embodiment of the present invention;

[0056] Figure 10 Schematic diagram of the preparation state of the green light quantum dot aggregation region in the embodiment of the present invention;

[0057] Figure 11 Schematic diagram of the preparation state of the green light self-assembled quantum layer in the embodiment of the present invention;

[0058] Figure 12 Schematic diagram of the preparation state of the third dielectric layer in the embodiment of the present invention;

[0059] Figure 13 Schematic diagram of the structure of the full-color LED device in the embodiment of the present invention. Detailed implementation manners

[0060] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0061] Embodiment 1:

[0062] Figure 1 Shows the flowchart of the preparation method of the full-color LED device in the embodiment of the present invention, Figure 2 Shows the schematic diagram of the structure of the single blue display module in the embodiment of the present invention, and the preparation method includes:

[0063] S11: Prepare a self-assembled red light quantum dot solution and a self-assembled green light quantum dot solution.

[0064] Specifically, the preparation process of the self-assembled red light quantum dot solution is as follows:

[0065] Based on Cs2CO3, oleic acid and octadecene, a cesium oleate precursor is prepared by mixing. The cesium carbonate, oleic acid and octadecene solution are mixed, the heating temperature is set between 100 °C and 120 °C, and the mixed solution is continuously heated for 2 h, so as to remove the moisture and oxygen in the mixed solution.

[0066] After the initial heating is completed, by raising the heating temperature, the heating temperature of the mixed solution is brought to 150°C to 180°C, thereby promoting the reaction between cesium carbonate, oleic acid, and octadecene in the mixed solution. After completely dissolving the cesium carbonate in the mixed solution, a cesium oleate precursor is obtained.

[0067] Furthermore, the ratio of the oleic acid to the cesium carbonate is 1 mL: 0.15 g, and the ratio of the oleic acid to the octadecene is 1 mL: 15 mL, enabling the cesium carbonate to be completely dissolved in the oleic acid and octadecene, thereby preparing the cesium oleate precursor.

[0068] Furthermore, in this embodiment, cesium carbonate, oleic acid, and octadecene are mixed and heated at 110°C for 1 to 2 h. Setting the heating temperature at 110°C is conducive to energy conservation on the premise of fully removing water and oxygen, and has good cost performance; during the subsequent temperature increase reaction, the temperature is raised to 160°C so that the cesium carbonate can be completely dissolved to obtain the cesium oleate precursor. In the heating environment at 160°C, the cesium carbonate can be dissolved fully and rapidly, and at the same time, the volatilization of the solvent can be reduced; the ratio of the oleic acid to the cesium carbonate is configured as 1 mL: 0.108 g, and the ratio of the oleic acid to the octadecene is configured as 1 mL: 10 mL.

[0069] Based on the mixture of PbI2 and octadecene to form a first mixed solution, oleic acid and oleylamine are injected into the first mixed solution under nitrogen protection to obtain a lead iodide precursor.

[0070] Specifically, lead iodide and octadecene are mixed, the temperature is set at 120°C, and after mixing the lead iodide and octadecene solution, stirring is carried out under vacuum conditions for 2 hours to fully remove the moisture in the solution and obtain the first mixed solution;

[0071] Furthermore, the ratio of octadecene to lead iodide is set as 1 mL: 0.0125 g.

[0072] Under nitrogen protection, oleic acid and oleylamine are injected into the first mixed solution to obtain a lead iodide precursor, wherein: the ratio of oleic acid, oleylamine, and octadecene is set as 1 mL: 1 mL: 10 mL.

[0073] The cesium oleate precursor is rapidly injected into the heated lead iodide precursor to obtain a CsPbI3 crude solution.

[0074] The lead iodide precursor is heated to 180° C., and a cesium oleate precursor is quickly injected into the lead iodide precursor, the injection time is less than 2 seconds, and after the cesium oleate precursor and the lead iodide precursor react for 5 seconds, the test tube with the lead iodide precursor and the cesium oleate precursor is immersed in cold water for cooling, so that the mixed solution of the lead iodide precursor and the cesium oleate precursor can be cooled to room temperature, thereby obtaining a crude CsPbI3 solution.

[0075] Furthermore, the ratio of the cesium oleate precursor to the lead iodide precursor is 1 ml:10.91 ml, which can meet the preparation requirements of the CsPbI3 crude solution.

[0076] Furthermore, the cesium oleate precursor and the lead iodide precursor can effectively produce CsPbI3 crystals at 140°C, and excessive reaction of the cesium oleate precursor and the lead iodide precursor to produce precipitation can be avoided by rapid cooling.

[0077] Specifically, the CsPbI3 crude solution is purified to obtain a CsPbI3 perovskite quantum dot solution.

[0078] An ethyl acetate solution is added to the crude CsPbI3 solution, wherein the amount of the ethyl acetate solution added is configured to be 3 times the volume of the crude CsPbI3 solution, and the crude CsPbI3 solution and the ethyl acetate solution are fully mixed to obtain a first mixed solution.

[0079] Further, the first mixed liquid is placed in a centrifuge, the speed of the centrifuge is set to 12000 rpm, and the working time is 15 minutes to obtain a first precipitate, the first precipitate is dispersed in toluene, and 3 times the volume of ethyl acetate solution is added to obtain a second mixed liquid.

[0080] Further, the second mixed liquid is placed in a centrifuge, and the speed of the centrifuge is set to be between 6000 rpm and 10000 rpm, and the working time is 15 minutes, so as to obtain a second precipitate;

[0081] The above precipitation operation is repeated. After at least 4 precipitation operations, the precipitate is dispersed in a toluene solution to obtain a CsPbI3 perovskite quantum dot solution.

[0082] Specifically, the CsPbI3 perovskite quantum dot solution is subjected to thiol ligand exchange to obtain a thiol self-assembled CsPbI3 red light quantum dot solution.

[0083] Specifically, 1,4-benzenedimethanethiol is dissolved in diethyl ether. The amount of 1,4-benzenedimethanethiol is set to 20 mg, and the volume of the diethyl ether is set to 1 ml. The mixture of 1,4-benzenedimethanethiol and the diethyl ether is added into the CsPbI3 perovskite quantum dot solution, and oleylamine is added into the CsPbI3 perovskite quantum dot solution. The addition amount of the oleylamine is 20 μl. After stirring for 10 min, centrifugal precipitation is carried out with an acetic acid ethyl ester solution with a volume three times that of the mixture, and the precipitate is dispersed in 5 ml of toluene reagent, thereby obtaining a self-assembled CsPbI3 red light quantum dot solution with thiol self-assembly characteristics.

[0084] Specifically, the preparation method of the self-assembled green light quantum dot solution includes:

[0085] Indium oleate is prepared based on indium chloride and oleic acid. An InP core solution is prepared by combining tris(trimethylsilyl)phosphine solution and octadecene solution. Indium chloride (InCl3) and 3 ml of oleic acid (OA) are subjected to vacuum dehydration at a temperature of 120 °C. After 2 hours of vacuum dehydration, indium oleate (In(OA)3) is formed. The concentration of the indium oleate solution is: 0.03 M. Tris(trimethylsilyl)phosphine ((TMS)3P) is dissolved in 10 ml of octadecene (ODE), and the concentration of tris(trimethylsilyl)phosphine ((TMS)3P) in the solution after dissolution is 0.1 M.

[0086] Further, under argon protection, In(OA)3) is mixed with 10 ml of ODE and heated to 280 °C. The (TMS)3P solution is rapidly injected, where the molar ratio of In:P = 1:3. After a reaction time of 10 minutes, an InP core is formed. The size of the InP core is about 3 nm, and the emission wavelength is 520 nm.

[0087] Zn(St)2 and an S precursor are alternately added dropwise to the InP core solution to obtain a crude InP / ZnS quantum dot solution.

[0088] Specifically, the InP core solution is cooled to 180 °C, and zinc stearate (Zn(St)2) is dissolved in 3 ml of ODE (0.1 M). Zn(St)2 and the S precursor are alternately added dropwise to the InP core solution, and 1 ml of the Zn(St)2 solution or the S precursor solution is added each time. The next addition is carried out after an interval of 10 minutes each time. A total of 3 layers of ZnS shell layers are deposited, and finally a crude InP / ZnS quantum dot solution is obtained.

[0089] The crude InP / ZnS quantum dot solution is purified based on an acetic acid ethyl ester solution to obtain an InP / ZnS quantum dot solution.

[0090] Specifically, an ethyl acetate solution is added to the InP / ZnS quantum dot crude solution. The addition amount of the ethyl acetate solution is configured to be 3 times the volume of the InP / ZnS quantum dot crude solution, and the InP / ZnS quantum dot crude solution and the ethyl acetate solution are fully mixed to obtain a third mixed solution.

[0091] Further, the third mixed solution is placed in a centrifuge, and the rotation speed of the centrifuge is set to 12000 rpm, and the working duration is 15 min, so as to obtain a third precipitate. The third precipitate is dispersed in n-hexane, and an ethyl acetate solution with 3 times the volume is added to obtain a fourth mixed solution.

[0092] Further, the fourth mixed solution is placed in a centrifuge, and the rotation speed range of the centrifuge is set between 6000 rpm and 10000 rpm, and the working duration is 15 min, so as to obtain a fourth precipitate;

[0093] The above precipitation operation is repeated. After at least 4 precipitation operations, the precipitate is dispersed into a n-hexane solution, so as to obtain an InP / ZnS quantum dot solution.

[0094] Specifically, the InP / ZnS quantum dot solution is subjected to a citric acid ligand exchange treatment to obtain a self-assembled green light quantum dot solution. The InP / ZnS quantum dot solution and citric acid are added to ethanol according to a molar ratio of 1:1000, and ultrasonic treatment is performed for 30 minutes, and NaOH is added to adjust the pH to 9-10, so that the carboxyl group is deprotonated (-COO-), and the quantum dots are transferred to the ethanol phase.

[0095] Finally, centrifugation treatment is performed by a centrifuge to remove unreacted ligands. The quantum dots are dispersed into a 5 ml ethanol solution, and a small amount of ethanolamine is added to adjust the pH to 7 to prevent the quantum dots from aggregating, so as to obtain a self-assembled green light quantum dot solution.

[0096] Further, the rotation speed of the centrifuge is set to 8000 rpm, and the working duration of the centrifuge is set to 10 min.

[0097] S12: Prepare a single blue display module, and set a first dielectric layer 3 on the top layer of the display module.

[0098] Specifically, Figure 3 shows a schematic structural diagram of the preparation state of the first dielectric layer in the embodiment of the present invention; prepare a single blue display module, and the single blue display module includes: a CMOS control substrate, a stress release layer, a bonding layer, a bottom ITO (Indium Tin Oxide), N-GaN, MQW (multiple quantum well), P-GaN, a top ITO, and a top reflection structure.

[0099] The material of the first dielectric layer 3 can be one or more of SiO2, Si3N4, Al2O3, AlN or HfO2. The thickness of the first dielectric layer 3 is 50nm - 100nm; in this embodiment, the thickness of the first dielectric layer 3 is set to 50nm, and the first dielectric layer 3 is formed by combining a SiO2 layer and a Si3N4 layer, wherein the Si3N4 layer covers the SiO2 layer.

[0100] Furthermore, the thickness of the SiO2 layer is 30nm, and the thickness of the Si3N4 layer is 20nm, which can meet the support requirements of the red light self-assembled quantum layer.

[0101] Specifically, the first dielectric layer 3 is deposited on the wafer of the blue light display module 1 by ALD process. Based on the first dielectric layer 3 as the base layer, the top structure of the single blue display module is adjusted so that the single blue display module can meet the self-assembly preparation requirements of the light color conversion quantum layer.

[0102] Atomic Layer Deposition (ALD) is a high-precision thin film deposition technology based on chemical vapor deposition, which is a technology of depositing material substances layer by layer on the substrate surface in the form of a single atomic film based on chemical vapor.

[0103] S13: Set the red light quantum dot aggregation area on the first dielectric layer 3 through photolithography process.

[0104] Specifically, Figure 4 It shows the schematic diagram of the preparation state structure of the ITO nanometer thin film in the embodiment of the present invention. The ITO nanometer thin film 2 is deposited and grown on the surface of the first dielectric layer 3 by electron beam, and the surface of the ITO nanometer thin film 2 is treated. The thickness of the ITO is 50nm, the light transmittance of the ITO layer ≥ 95%, and the ITO nanometer thin film 2 is grown on the first dielectric layer 3 based on the electron beam evaporation process, without the need for high-temperature heat treatment, which can meet the preparation requirements of the display module.

[0105] Specifically, the surface of the ITO thin film can be treated with oxygen plasma. Set the power of the plasma to 300W and the oxygen flow rate to 100sccm, and bombard the ITO thin film without bias voltage and continuously treat for 30min. Through plasma surface treatment, the surface of the ITO thin film can be cleaned and the surface characteristics of the ITO thin film can be activated, thereby improving the surface performance of the ITO thin film and enhancing the adhesion performance of the material.

[0106] Perform lithography on the surface of the ITO film after surface treatment. Use positive photoresist or negative photoresist to perform lithography on the surface of the ITO film. After exposure and development, a number of window positions are formed on the ITO film, and the red light quantum dot aggregation region is exposed on the ITO film based on the window positions.

[0107] Further, in this embodiment, lithography is performed on the ITO film by using negative photoresist. After development, a number of window structures are formed on the negative photoresist layer, so that a number of aggregation positions of the red light quantum layers can be exposed on the surface of the ITO layer.

[0108] S14: Form a red light self-assembled quantum layer in the red light quantum dot aggregation region through self-assembly of red light quantum dot solution.

[0109] Figure 5 Shows the schematic diagram of the preparation state structure of the red light quantum dot aggregation region in the embodiment of the present invention; Figure 6 Shows the flowchart of the preparation method of the red light self-assembled quantum layer in the embodiment of the present invention. The preparation method of the red light self-assembled quantum layer 4 includes:

[0110] S141: Etch the wafer with hydrofluoric acid solution and remove the photoresist on the wafer.

[0111] Specifically, place the wafer after lithography treatment in the hydrofluoric acid solution, where the volume ratio of the hydrofluoric acid solution is HF:H2O = 1:4, and soak the wafer in the room temperature environment for 5 - 10 minutes. Chemically etch the first dielectric layer 3 based on the hydrofluoric acid solution. In this embodiment, the preferred soaking time of the wafer is 5 minutes, so that the hydrofluoric acid solution can preferentially etch the SnO2 phase in the ITO, thereby exposing the underlying In2O3 of the ITO film, and enriching In on the surface of the red light quantum dot aggregation region 3+ , so as to perform the assembly of the red light quantum layer in the red light quantum dot aggregation region subsequently.

[0112] Further, after etching and activating the red light quantum dot aggregation region with the hydrofluoric acid solution, use acetone solution to remove the photoresist, so that the photoresist can be dissolved in the acetone solution, and clean the photoresist on the wafer, so as to meet the aggregation self-assembly operation of the red light quantum layer on the wafer.

[0113] S142: Immerse the wafer after removing the photoresist in the self-assembled red light quantum dot solution to obtain the first red light quantum layer 41.

[0114] Figure 7It shows a schematic diagram of the preparation state of the first red light quantum layer in an embodiment of the present invention; the wafer after the degumming operation is completely immersed in the self-assembled red light quantum dot solution and soaked for 30 s continuously, so that the red light quantum dots in the self-assembled red light quantum dot solution can be in the In of the red light quantum dot aggregation region 3+ region for self-assembly. On the surface of the wafer corresponding to the red light quantum dot aggregation region, a number of In are formed based on the hydrofluoric acid solution 3+ cations. When the wafer is immersed in the self-assembled red light quantum dot solution, the red light quantum dots in the self-assembled red light quantum dot solution can agglomerate in the red light quantum dot aggregation region based on the attraction of the 3+ cations, so that the red light quantum dots in the self-assembled red light quantum dot solution are aggregated to form the first red light quantum layer 41.

[0115] S143: Rinse the first red light quantum layer 41 with ethyl acetate.

[0116] Specifically, rinse the first red light quantum layer 41 by spin coating method. Take 5 ml of ethyl acetate for dynamic spin coating on the surface of the wafer. Set the spin coating speed to 500 r / min and the spin coating time to 20 s. Based on the ethyl acetate, surface treatment of the first red light quantum layer 41 can activate the In on the surface of the first red light quantum layer 41 3+ ions, so that the self-assembly operation of the second red light quantum layer 42 can be carried out on the surface of the first red light quantum layer 41.

[0117] S144: Place the rinsed wafer in the self-assembled red light quantum dot solution for soaking to prepare the second red light quantum layer 42 on the surface of the first red light quantum layer 41.

[0118] Figure 8 It shows a schematic diagram of the preparation state of the second red light quantum layer in an embodiment of the present invention; place the wafer rinsed with the ethyl acetate solution in the self-assembled red light quantum dot solution for soaking, set the soaking time to 30 s, so that the red light quantum dots in the self-assembled red light quantum dot solution can aggregate on the surface of the first red light quantum layer 41, and form the second red light quantum layer 42 based on the aggregation of red light quantum dots. Moreover, the thickness of the second red light quantum layer 42 forms a spherical lens structure based on surface tension, which can effectively improve the light extraction efficiency of the red light self-assembled quantum layer.

[0119] Further, according to the actual preparation requirements of the full-color LED device, steps S143 and S144 can be repeated to form a red self-assembled quantum layer with a certain thickness by laminating multiple layers of red self-assembled quantum layers. Based on the red self-assembled quantum layer, the light extraction efficiency of converting blue light to red light can be satisfied, and the red self-assembled quantum layer can avoid the occurrence of blue light leakage, that is, reduce the risk of light leakage.

[0120] Further, in this embodiment, through 4 times of the red quantum dot self-assembly operation, the thickness of the red self-assembled quantum layer is 3 μm, so that the red self-assembled quantum layer has a sufficient thickness to meet the light extraction effect of converting blue light to red light. At the same time, it can avoid the phenomenon of light self-absorption caused by the over-thickness of the red self-assembled quantum layer, and can ensure that the full-color LED device has a good light extraction efficiency.

[0121] S15: A second dielectric layer 5 is provided on the red self-assembled quantum layer.

[0122] Specifically, Figure 9 The schematic diagram of the preparation state of the second dielectric layer in the embodiment of the present invention is shown. The second dielectric layer 5 is deposited and prepared on the red self-assembled quantum layer by ALD process. The second dielectric layer 5 is used to protect the red self-assembled quantum layer 4 and avoid damage to the structure of the red self-assembled quantum layer 4 during the preparation process of the green self-assembled quantum layer 6.

[0123] Further, the material of the second dielectric layer 5 can be one or more of SiO2, Si3N4, Al2O3, AlN, HfO2. The thickness value range of the second dielectric layer 5 is: 10 nm to 20 nm. In this embodiment, the thickness of the second dielectric layer 5 is preferably 15 nm, and the material of the second dielectric layer 5 is SiO2, so that the second dielectric layer 5 can be used as the dielectric protection layer of the red self-assembled quantum layer and meet the self-assembly deposition requirements of the green self-assembled quantum layer 6.

[0124] S16: A green quantum dot aggregation region is provided on the second dielectric layer 5 by photolithography.

[0125] Specifically, Figure 10 The schematic diagram of the preparation state of the green quantum dot aggregation region in the embodiment of the present invention is shown; positive photoresist or negative photoresist can be used for photolithography treatment to form a patterned mask on the second dielectric layer 5, so as to prepare the green quantum dot aggregation region on the second dielectric layer 5.

[0126] In this embodiment, by setting negative photoresist, a patterned mask is formed on the surface of the second dielectric layer 5 through exposure and development, so as to expose the green quantum dot aggregation region on the photoresist of the second dielectric layer 5.

[0127] Further, according to the preparation requirements of the full-color LED device, the setting position of the green self-assembled quantum layer 6 is set on the photoresist of the second dielectric layer 5, so that the green self-assembled quantum layer 6 can meet the preparation requirements of the full-color LED device.

[0128] S17: Form a green self-assembled quantum layer in the green quantum dot aggregation region through a self-assembled green quantum dot solution.

[0129] Figure 11 The schematic diagram of the preparation state of the green self-assembled quantum layer in the embodiment of the present invention is shown. The surface of the wafer is treated to activate the green quantum dot aggregation region on the surface of the wafer, and the wafer after surface treatment is immersed in the self-assembled green quantum dot solution. Based on the self-assembly of the green quantum dots in the self-assembled green quantum dot solution, a green self-assembled quantum layer is formed.

[0130] Place the wafer in the BOE solution, and set the volume ratio of the BOE solution as: the ratio of the BOE solution is HF:NH4F = 1:10. Immerse it at room temperature for 1 min to remove the second dielectric layer 5 in the green quantum dot aggregation region under the pattern mask, so that the wafer can expose the ITO layer in the green quantum dot aggregation region.

[0131] After the wafer is treated with the BOE solution, the treated wafer can be immersed in an aqueous solution of ethylenediaminetetraacetic acid (EDTA). The concentration range of the EDTA standard solution is 0.01 - 0.05 mol / L. In this embodiment, by using a 0.05 mol / L aqueous solution of EDTA, the immersion time of the wafer is set to 15 min, so that Sn4+ ions are enriched on the ITO surface in the green quantum dot aggregation region of the wafer after immersion, which can thus meet the aggregation of green quantum dots and realize the self-assembly operation of green quantum dots.

[0132] Further, acetone solvent is used to remove the photoresist. After degluing, the wafer is placed in the prepared self-assembled green quantum dot solution and immersed for 30 s, so that the green quantum dots will self-assemble in the Sn4+ region to form a first green quantum layer. In other untreated regions, the hydrophobic quantum dots avoid staying on the surface of the second dielectric layer 5.

[0133] Specifically, acetone is used to rinse the first green quantum layer. In this embodiment, 5 ml of acetone is dynamically spin-coated on the surface of the wafer by the spin-coating method, and the rotation speed is set to 500 r and the time is 20 s, so as to activate the Sn4+ particles on the surface of the first green quantum layer. Based on the activated surface of the first green quantum layer, the aggregation of green quantum dots in the green quantum dot solution is satisfied.

[0134] Further, the wafer after being treated with acetone is immersed in the prepared self-assembled green quantum dot solution for 30 s, so that the green quantum dots can self-assemble in the Sn4+ region, thereby self-assembling and forming a second green quantum layer on the surface of the first green quantum layer. The thickness of the second green quantum layer is thicker than that of the first green quantum layer, and due to surface tension, the quantum dots will self-assemble into a spherical lens structure, which is convenient for adjusting the light output effect.

[0135] Further, according to the preparation requirements of the full-color LED device, multiple green quantum layers can be sequentially prepared on the first green quantum layer. In this embodiment, the thickness of the green self-assembled quantum layer 6 is about 3 μm, which is achieved through four self-assembly operations, can meet the light output requirements of green light, and avoid the phenomenon of blue leakage.

[0136] S18: A third dielectric layer 7 is provided on the second dielectric layer 5 and the green self-assembled quantum layer.

[0137] Specifically, Figure 12 FIG. shows a schematic diagram of the preparation state of the third dielectric layer in the embodiment of the present invention. The third dielectric layer 7 is deposited on the surface of the red self-assembled quantum layer 4 of the wafer by ALD. The material of the third dielectric layer 7 can be SiO2, Si3N4, Al2O3, AlN or HfO2 to meet the protection requirements of the red self-assembled quantum layer.

[0138] Further, the thickness of the third dielectric layer 7 is 30 nm to 50 nm. In this embodiment, the thickness of the third dielectric layer 7 is set to 35 nm, and Al2O3 is selected as the material of the third dielectric layer 7 to meet the protection requirements of the red self-assembled quantum layer 4.

[0139] S19: A plurality of window positions are provided on the third dielectric layer 7 through a photolithography process to form a full-color LED device.

[0140] Specifically, a mask pattern is provided on the third dielectric layer 7 by a photolithography process. A positive photoresist is covered on the surface of the third dielectric layer 7, and the photoresist corresponding to the light output positions of blue light, red light and green light is retained after exposure and development. A metal reflective layer 8 is deposited on the pattern mask of the third dielectric layer 7 by electron beam deposition, and the light output efficiency of the full-color LED device is improved based on the metal reflective layer 8.

[0141] Further, the material of the metal reflective layer 8 can be aluminum metal or silver metal, which has a good light reflection effect, thereby improving the light output effect of the full-color LED device.

[0142] Further, in this embodiment, the material of the metal reflection layer 8 is set to silver, and the thickness of the metal reflection layer 8 is set to 2 μm to prevent light leakage from occurring in the metal reflection layer 8 and ensure the light output effect of the full-color LED device.

[0143] The embodiment of the present invention provides a preparation method of a full-color LED device and the full-color LED device. By adjusting the self-assembled red quantum dot solution and the self-assembled green quantum dot solution, surface treatment is performed on the single blue display module. The red self-assembled quantum layer 4 is formed by soaking in the self-assembled red quantum dot solution, and the green self-assembled quantum layer 6 is formed by soaking in the self-assembled green quantum dot solution, which can improve the self-assembly binding ability of the quantum layer on the device surface, thereby improving the structural connection stability of the full-color LED device, effectively reducing the risk of light leakage, and ensuring the light color conversion effect and light output efficiency of the full-color LED device.

[0144] Embodiment 2:

[0145] Figure 13 The structural schematic diagram of the full-color LED device in the embodiment of the present invention is shown. The full-color LED device includes:

[0146] A blue light display module 1, a red self-assembled quantum layer 4 and a green self-assembled quantum layer 6 provided on the blue light display module 1;

[0147] A metal reflection layer 8 is provided at the top of the full-color LED device, and a plurality of window structures are provided in the metal reflection layer 8. The full-color LED device forms a blue light output channel, a red light output channel and a green light output channel based on the plurality of window structures.

[0148] Further, the thickness of the metal reflection layer 8 is 2 μm, and the material of the metal reflection layer 8 can be aluminum metal or silver metal, which can meet the blue light, green light and red light output efficiencies of the full-color LED device.

[0149] Specifically, the full-color LED device further includes a first dielectric layer 3, a second dielectric layer 5 and a third dielectric layer 7. The first dielectric layer 3 is provided between the blue light display module 1 and the red self-assembled quantum layer 4, the second dielectric layer 5 is provided between the red self-assembled quantum layer 4 and the green self-assembled quantum layer 6, and the third dielectric layer 7 is provided between the green self-assembled quantum layer 6 and the metal reflection layer 8. Electrical isolation of the blue light display module 1, the red self-assembled quantum layer 4 and the green self-assembled quantum layer 6 is performed based on the first dielectric layer 3, the second dielectric layer 5 and the third dielectric layer 7, and mechanical protection of the red self-assembled quantum layer 4 and the green self-assembled quantum layer 6 is performed to reduce the damage risk of the full-color LED device.

[0150] In addition, the embodiments of the present invention have been introduced in detail above. Specific examples have been used in this article to elaborate on the principles and implementation manners of the present invention. The description of the above embodiments is only for helping to understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A method for preparing a full-color LED device, characterized in that, The preparation method includes: Preparing a self-assembled red quantum dot solution and a self-assembled green quantum dot solution; Preparing a single blue display module and setting a first dielectric layer on the top layer of the display module; Setting a red quantum dot aggregation region on the first dielectric layer through a lithography process; Forming a red self-assembled quantum layer in the red quantum dot aggregation region through the self-assembled red quantum dot solution; A second dielectric layer is provided on the red self-assembled quantum layer; Setting a green quantum dot aggregation region on the first dielectric layer through a lithography process; Forming a green self-assembled quantum layer in the green quantum dot aggregation region through the self-assembled green quantum dot solution; Setting a third dielectric layer on the second dielectric layer and the green self-assembled quantum layer; Setting a plurality of window positions on the third dielectric layer through a lithography process to form a full-color LED device.

2. The method for preparing a full-color LED device according to claim 1, wherein The preparation of the self-assembled red quantum dot solution includes: Preparing a cesium oleate precursor by mixing Cs2CO3, oleic acid, and octadecene; Mixing PbI2 and octadecene to form a first mixed solution, and injecting oleic acid and oleylamine into the first mixed solution under nitrogen protection to obtain a lead iodide precursor; Rapidly injecting the heated cesium oleate precursor into the heated lead iodide precursor to obtain a CsPbI3 crude solution; Purifying the CsPbI3 crude solution to obtain a CsPbI3 perovskite quantum dot solution; Performing a thiol ligand exchange on the CsPbI3 perovskite quantum dot solution to obtain a mercapto self-assembled CsPbI3 red quantum dot solution.

3. The manufacturing method of the full-color LED device according to claim 1, characterized in that, The preparation of the self-assembled green quantum dot solution includes: Formulating indium oleate based on indium chloride and oleic acid, and preparing an InP core solution by combining a triphosphorus solution and an octadecene solution; Alternately dropping Zn(St)2 and an S precursor into the InP core solution to obtain an InP / ZnS quantum dot crude solution; Purifying the InP / ZnS quantum dot crude solution based on an ethyl acetate solution to obtain an InP / ZnS quantum dot solution; Performing a citric acid ligand exchange treatment on the InP / ZnS quantum dot solution to obtain a self-assembled green quantum dot solution.

4. The method for preparing a full-color LED device according to claim 3, wherein The performing a citric acid ligand exchange treatment on the InP / ZnS quantum dot solution to obtain a self-assembled green quantum dot solution includes: Adding the InP / ZnS quantum dot solution and citric acid to ethanol at a molar ratio of 1:1000, and after ultrasonic treatment, adding NaOH to adjust the pH value to 9-10 to obtain a preliminary reaction solution; Processing the preliminary reaction solution in a centrifuge, setting the rotation speed of the centrifuge to 8000 rpm, and setting the working time of the centrifuge to 10 min to obtain a separated solution; Adding ethanolamine to the separated solution to adjust the pH value to 7 to obtain a self-assembled green quantum dot solution.

5. The manufacturing method of the full-color LED device according to claim 1, characterized in that, The setting a red quantum dot aggregation region on the first dielectric layer through a lithography process includes: Evaporating and growing an ITO nanometer thin film on the surface of the first dielectric layer through an electron beam, and performing a surface treatment on the ITO nanometer thin film; Performing a lithography treatment on the surface of the ITO thin film after the surface treatment to form a plurality of window positions, and exposing the red quantum dot aggregation region on the ITO thin film based on the window positions.

6. The method for preparing a full-color LED device according to claim 1, characterized in that, The formation of the red self-assembled quantum layer by the self-assembled red quantum dot solution in the red quantum dot aggregation region includes: Etching the wafer with hydrofluoric acid solution and removing the photoresist on the wafer; Placing the wafer after photoresist removal in the self-assembled red quantum dot solution for soaking to obtain a first red quantum layer; Rinsing the first red quantum layer with ethyl acetate; Placing the rinsed wafer in the self-assembled red quantum dot solution for soaking to fabricate a second red quantum layer on the surface of the first red quantum layer.

7. The method for preparing a full-color LED device according to claim 6, wherein The rinsing of the first red quantum layer with ethyl acetate includes: Rinsing the first red quantum layer by spin coating method. Taking 5 ml of ethyl acetate for dynamic spin coating on the wafer surface, setting the spin coating speed at 500 r / min and the spin coating time at 20 s to perform surface treatment on the first red quantum layer based on the ethyl acetate.

8. The manufacturing method of the full-color LED device according to claim 1, wherein, The formation of the green self-assembled quantum layer by the self-assembled green quantum dot solution in the green quantum dot aggregation region includes: Performing surface treatment on the wafer to activate the green quantum dot aggregation region on the wafer surface, and soaking the wafer after surface treatment in the self-assembled green quantum dot solution to form the green self-assembled quantum layer by self-assembly of the green quantum dots in the self-assembled green quantum dot solution.

9. A full-color LED device, characterized in that, The full-color LED device is fabricated based on the preparation method of the full-color LED device according to any one of claims 1 to 8, and the full-color LED device includes: A blue light display module, a red self-assembled quantum layer and a green self-assembled quantum layer provided on the blue light display module; A metal reflective layer is provided on the top of the full-color LED device, and a plurality of window structures are formed in the metal reflective layer. The full-color LED device forms a blue light output channel, a red light output channel and a green light output channel based on the plurality of window structures.

10. The full-color LED device according to claim 9, wherein The thickness of the metal reflective layer is 2 μm.

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