Light-emitting device, method for manufacturing the same, and display panel

Abstract

The application discloses a light-emitting device, a manufacturing method thereof and a display panel. The manufacturing method of the light-emitting device comprises the following steps: providing a device plate, wherein the device plate has a first surface and a second surface arranged oppositely; forming a quantum dot light-emitting layer on the first surface; sequentially forming an electron transport layer and a cathode on the quantum dot light-emitting layer, wherein the Fermi level difference between the electron transport layer and the quantum dot light-emitting layer is less than or equal to 0.5 eV. The light-emitting device, the manufacturing method thereof and the display panel are used for improving the light-emitting efficiency of the light-emitting device.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to a light-emitting device, a manufacturing method thereof and a display panel. BACKGROUND

[0002] Quantum dot electroluminescent display technology has become the best candidate for the next generation of display technology due to its wavelength adjustability, high color saturation, high material stability, and low preparation cost. After nearly two decades of development, the external quantum efficiency of quantum dot light emitting diodes (QLED) has increased from 0.01% to more than 20%. From the aspect of device efficiency, QLED has been quite close to organic light emitting diodes (OLED). However, despite the advantages of quantum dot light emitting devices, the performance of the current devices still does not fully meet the requirements of industrialization.

[0003] Therefore, it is necessary to provide a new technical solution to solve the above technical problems. SUMMARY

[0004] The present application provides a light-emitting device, a manufacturing method thereof and a display panel, which are used to improve the light-emitting efficiency of the light-emitting device.

[0005] The present application provides a manufacturing method of a light-emitting device, which comprises the following steps:

[0006] A device board is provided, which has a first surface and a second surface arranged oppositely;

[0007] A quantum dot light-emitting layer is formed on the first surface;

[0008] An electron transport layer and a cathode are sequentially formed on the quantum dot light-emitting layer, and the Fermi level difference between the electron transport layer and the quantum dot light-emitting layer is less than or equal to 0.5 eV.

[0009] In the manufacturing method of the light-emitting device provided in the present application, the quantum dot light-emitting layer comprises quantum dot material doped with halogen.

[0010] In the manufacturing method of the light-emitting device provided in the present application, the quantum dot light-emitting layer is made by modifying the surface of quantum dot material with halogen.

[0011] In the manufacturing method of the light-emitting device provided in the present application, the step of making the quantum dot light-emitting layer by modifying the surface of quantum dot material with halogen comprises:

[0012] Metal halide is mixed with the quantum dot material to form quantum dot material with halogen modification.

[0013] The halogen-modified quantum dot material is arranged on the first surface to form the quantum dot light-emitting layer.

[0014] In the method for manufacturing the light-emitting device provided in the embodiments of the present application, the concentration of the metal halide is less than or equal to 2 mg / mL, the concentration of the quantum dot material is between 20 mg / mL and 40 mg / mL, and the volume ratio of the metal halide to the quantum dot material is between 1:20 and 1:35.

[0015] In the method for manufacturing the light-emitting device provided in the embodiments of the present application, the step of preparing the quantum dot light-emitting layer by halogen-modifying the surface of the quantum dot material includes:

[0016] After the quantum dot material is arranged on the first surface, a film-forming treatment is performed;

[0017] A metal halide solution is arranged on the surface of the quantum dot material, and a heating treatment is performed to form the quantum dot light-emitting layer.

[0018] In the method for manufacturing the light-emitting device provided in the embodiments of the present application, the metal ion in the metal halide is selected from any one of K + , Na + , Zn 2+ , and the halogen ion in the metal halide is selected from any one of Cl - , Br - , and I - .

[0019] In the method for manufacturing the light-emitting device provided in the embodiments of the present application, the material of the quantum dot light-emitting layer is a quantum dot material containing cadmium, zinc, selenium and sulfur, and the content ratio of the cadmium and the zinc is greater than 1:1.

[0020] The embodiments of the present application also provide a light-emitting device, which includes:

[0021] a device plate having a first surface and a second surface arranged oppositely;

[0022] a quantum dot light-emitting layer arranged on the first surface;

[0023] an electron transport layer arranged on a surface of the quantum dot light-emitting layer away from the device plate, and the Fermi level difference between the electron transport layer and the quantum dot light-emitting layer is less than or equal to 0.5 eV.

[0024] In the light-emitting device provided in the embodiments of the present application, the quantum dot light-emitting layer includes a halogen-doped quantum dot material.

[0025] In the light-emitting device provided in the embodiments of the present application, the quantum dot light-emitting layer is made of quantum dot material with halogen modified on the surface thereof.

[0026] In the light-emitting device provided in the embodiments of the present application, the halogen includes at least one of Cl - , Br - , and I - .

[0027] In the light-emitting device provided in the embodiments of the present application, the material of the quantum dot light-emitting layer is quantum dot material containing cadmium element, zinc element, selenium element and sulfur element, wherein the content ratio of the cadmium element and the zinc element is greater than 1:1.

[0028] In the light-emitting device provided in the embodiments of the present application, the material of the quantum dot light-emitting layer is at least one of CdS, CdSe, ZnSe, Zn X Cd 1-X S, Zn X Cd 1-X Se, Zn X Se 1-X S, Zn X Cd 1-X S / ZnSe, Zn X Cd 1-X Se / ZnS, Zn X Cd 1-X Se / ZnSe / ZnS, wherein X is less than or equal to 1.

[0029] In the light-emitting device provided in the embodiments of the present application, the light-emitting device further includes:

[0030] a cathode, which is arranged on the side of the electron transport layer away from the quantum dot light-emitting layer.

[0031] The embodiments of the present application also provide a display panel, which includes the light-emitting device and an array substrate, and the light-emitting device is arranged on the array substrate.

[0032] The embodiments of the present application provide a light-emitting device, a manufacturing method thereof and a display panel. In the manufacturing method of the light-emitting device provided in the embodiments of the present application, the Fermi level difference between the electron transport layer and the quantum dot light-emitting layer is reduced, so that the potential barrier between the electron transport layer and the quantum dot light-emitting layer is reduced, which is beneficial to the transmission of electrons from the electron transport layer to the quantum dot light-emitting layer, and the light-emitting efficiency of the light-emitting device is improved.

[0033] In order to make the above content of the present application more obvious and easy to understand, the following preferred embodiments are described in detail below, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 A structure schematic diagram of a light emitting device provided by an embodiment of the present application is shown in FIG. 1.

[0035] Figure 2 A step flow chart of a manufacturing method of a light emitting device provided by an embodiment of the present application is shown in FIG. 2.

[0036] Figures 3-4 A structure schematic diagram of a light emitting device provided by an embodiment of the present application is shown in FIG. 1.

[0037] Figure 5 A structure schematic diagram of a display panel provided by an embodiment of the present application is shown in FIG. 3. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the present application clearer, the following will further describe the present application in detail with reference to the accompanying drawings, wherein the same component symbols represent the same components, and the following description is based on the shown specific embodiments of the present application, which should not be regarded as limiting other specific embodiments of the present application not described in detail herein. The word "embodiment" used in the present description means example, illustration or exemplification.

[0039] The present application provides a light emitting device, a manufacturing method thereof and a display panel, which will be described in detail below. It should be noted that the description order of the following embodiments is not regarded as limiting the preferred order of the embodiments.

[0040] Please refer to Figure 1 , Figure 1 A structure schematic diagram of a light emitting device provided by an embodiment of the present application is shown in FIG. 1. The present application provides a light emitting device 100, which comprises a device plate 101, a quantum dot light emitting layer 102, an electron transport layer 103 and a cathode 104.

[0041] In an embodiment, the device plate 101 comprises an anode 101a, a hole injection layer 101b and a hole transport layer 101c which are sequentially stacked.

[0042] In an embodiment, the anode 101a can be transparent conductive oxide or conductive polymer, and the transparent conductive oxide can be indium tin oxide (ITO), SnO2 conductive glass doped with fluorine (SnO2:F) and the like.

[0043] The hole injection layer 101b can be conductive polymer, for example: PEDOT:PSS; or high work function n-type semiconductor, for example: HAT-CN, MoO3, WO3, V2O5, Rb2O and the like.

[0044] The hole transport layer 101c can be an organic hole transport layer, such as Poly-TPD, TFB, PVK, TCTA, CBP, NPB, NPD, etc., or an inorganic hole transport layer, such as NiO, Cu2O, CuSCN, etc.

[0045] The quantum dot light-emitting layer 102 is disposed on the first surface 1011.

[0046] In some embodiments, the quantum dot light-emitting layer 102 comprises halogen-doped quantum dot material, wherein the quantum dot light-emitting layer 102 is made by modifying the surface of the quantum dot material with halogen.

[0047] In some embodiments, the quantum dot light-emitting layer 102 is formed by mixing metal halide and quantum dot material; or the quantum dot light-emitting layer 102 is formed by modifying solidified quantum dot material.

[0048] Specifically, the halogen comprises at least one of Cl - , Br - , and I - .

[0049] The quantum dot material can be a II-VI compound semiconductor, such as CdSe, ZnCdS, CdSeS, ZnCdSeS, CdSe / ZnS, CdSeS / ZnS, CdSe / CdS, CdSe / CdS / ZnS, ZnCdS / ZnS, CdS / ZnS, ZnCdSeS / ZnS, etc.; a III-V compound semiconductor, such as InP, InP / ZnS, etc.; a I-III-VI compound semiconductor, such as CuInS, AgInS, CuInS / ZnS, AnInS / ZnS, etc.; a IV element semiconductor, such as Si, C, Graphene, etc.; or a perovskite quantum dot, such as CsPbM3(M = Cl, Br, I), etc.

[0050] The electron transport layer 103 is disposed on the side of the quantum dot light-emitting layer 102 away from the device plate 101. In some embodiments, the material of the electron transport layer 103 can be a metal oxide, wherein the metal oxide can be selected from at least one of ZnO, TiO2, Fe2O3, SnO2, Ta2O3, AlZnO, ZnSnO, and InSnO.

[0051] In an embodiment, the Fermi level difference between the electron transport layer 103 and the quantum dot light-emitting layer 102 is less than or equal to 0.5 eV. In the embodiment of the present application, by making the halogen-modified quantum dot light-emitting layer 102, the Fermi level of the quantum dot material is changed, so that the Fermi level of the electron transport layer 103 and the quantum dot light-emitting layer 102 is matched, the potential barrier of the electron transport layer 103 and the quantum dot light-emitting layer 102 is reduced, the electron transport from the electron transport layer 103 to the quantum dot light-emitting layer 102 is facilitated, the accumulation of electrons in the electron transport layer 103 is reduced, and the light-emitting efficiency of the light-emitting device 100 is improved.

[0052] It should be noted that the Fermi level refers to the highest energy level filled with electrons in the energy band of a solid at absolute zero temperature.

[0053] In another embodiment, the material of the quantum dot light-emitting layer is a quantum dot material containing cadmium, zinc, selenium and sulfur elements, wherein the content ratio of cadmium and zinc is greater than 1:1.

[0054] Specifically, in an embodiment, the material of the quantum dot light-emitting layer is at least one of CdS, CdSe, ZnSe, Zn X Cd 1-X S, Zn X Cd 1- X Se, Zn X Se 1-X S, Zn X Cd 1-X S / ZnSe, Zn X Cd 1-X Se / ZnS, Zn X Cd 1-X Se / ZnSe / ZnS, wherein X is less than or equal to 1.

[0055] The cathode 104 is arranged on the side of the electron transport layer 103 away from the quantum dot light-emitting layer 102. The material of the cathode 104 can be metal aluminum, magnesium, silver, etc.

[0056] Next, the manufacturing method of the light-emitting device will be described in the embodiments of the present application.

[0057] In the embodiments of the present application, the quantum dot light-emitting layer includes halogen-doped quantum dot material.

[0058] Specifically, the quantum dot light-emitting layer is made by halogen modification on the surface of the quantum dot material.

[0059] Please refer to Figure 1 , Figure 2 , Figure 3 and Figure 4 . The manufacturing method of the light-emitting device 100 includes the following steps:

[0060] Step B1: providing a device plate 101, the device plate 101 has a first surface 1011 and a second surface 1012 arranged oppositely, please refer to Figure 2 .

[0061] In some embodiments, the device plate 101 comprises an anode 101a, a hole injection layer 101b and a hole transport layer 101c arranged in sequence.

[0062] Specifically, the preparation steps of the device plate 101 are as follows: first, evaporating a layer of transparent conductive oxide or conductive polymer on the substrate as the anode 101a, the thickness of the anode 101a is between 20 nanometers and 60 nanometers; then, cleaning the anode 101a by ultraviolet ozone, which improves the surface wettability of the anode 101a and increases the work function of the anode 101a.

[0063] Subsequently, spin-coating a layer of PEDOT:PSS (poly 3,4-ethylenedioxythiophene: polystyrene sulfonate) material on the anode 101a, and then annealing the PEDOT:PSS at normal pressure to form the hole injection layer 101b. The spin-coating speed is between 3000 r / min and 5000 r / min, the spin-coating time is between 30 seconds and 50 seconds, the annealing temperature is between 120 degrees Celsius and 170 degrees Celsius, and the annealing time is between 10 minutes and 30 minutes.

[0064] Next, in the glove box without water and oxygen, spin-coating a layer of TFB material on the hole injection layer 101b, wherein the TFB is dissolved in chlorobenzene with a concentration between 6 mg / mL and 10 mg / mL, and then annealing the TFB solution to form the hole transport layer 101c. The spin-coating speed is between 2000 r / min and 4000 r / min, the spin-coating time is between 20 seconds and 40 seconds, the annealing temperature is between 120 degrees Celsius and 170 degrees Celsius, and the annealing time is between 10 minutes and 30 minutes.

[0065] Next, turn to step B2.

[0066] Step B2: forming a quantum dot light-emitting layer 102 on the first surface 1011, please refer to Figure 4 .

[0067] In an embodiment, step B2 comprises the following steps:

[0068] The metal halide is mixed with the quantum dot material to form a quantum dot material with halogen modification, wherein the concentration of the metal halide is less than or equal to 2 mg / mL, the concentration of the quantum dot material is between 20 mg / mL and 40 mg / mL, and the volume ratio of the metal halide to the quantum dot material is between 1:20 and 1:35. The concentration of the metal halide can be one of 0.2 mg / mL, 0.5 mg / mL, 0.8 mg / mL, 1.0 mg / mL, 1.5 mg / mL, and 2 mg / mL. The concentration of the quantum dot material can be any one of 20 mg / mL, 25 mg / mL, 30 mg / mL, 35 mg / mL, and 40 mg / mL. The volume ratio of the metal halide to the quantum dot material can be any one of 1:20, 1:25, 1:28, 1:30, and 1:35.

[0069] The concentration of the metal halide is less than or equal to 2 mg / mL, the concentration of the quantum dot material is between 20 mg / mL and 40 mg / mL, and the volume ratio of the metal halide to the quantum dot material is between 1:20 and 1:35. The halogen ions in the metal halide can replace the ligands on the surface of the quantum dot material to the maximum extent, and the luminescent efficiency of the quantum dot material is not affected, thereby forming a quantum dot material with halogen modification.

[0070] It should be noted that the concentration in the embodiments of the present application refers to the mass concentration, that is, a solution formed by dissolving a certain amount of solute in a certain volume of solvent has a certain concentration. In the embodiments, the solvent of the metal halide solution is the metal halide, and the solvent can be one of ethanol and methanol. For example, a 2 mg / mL halide solution is formed by dissolving 2 mg of metal halide in 1 mL of ethanol. A 40 mg / mL quantum dot solution is formed by dissolving 40 mg of quantum dot material in 1 mL of n-octane.

[0071] For example, in a specific embodiment, a 1.0 mL zinc chloride solution with a concentration of 1.0 mg / mL is mixed with a 30 mL quantum dot material solution with a concentration of 30 mg / mL. The mixed solution of zinc chloride and quantum dot material is heated at 100 to 110 degrees Celsius for about 1 hour. Then, the mixture of zinc chloride and quantum dot material is washed with ethanol, and the solid is dissolved in n-octane to obtain a halogen-modified quantum dot material. The solvent of the zinc chloride solution can be ethanol or methanol, etc.

[0072] The halogen-modified quantum dot material is arranged on the first surface 1011 to form a quantum dot light-emitting layer 102.

[0073] Specifically, in a glove box without water and oxygen, halogen-modified quantum dot material is coated on the first surface 1011 by using inkjet printing process or spin coating process, and the halogen-modified quantum dot material is annealed at 80-120 degrees Celsius, wherein the annealing time is 10-30 minutes, thereby forming the quantum dot light-emitting layer 102.

[0074] In an embodiment, the metal ion in the metal halide is selected from any one of K + , Na + , Zn 2+ , and the halogen ion in the metal halide is selected from any one of Cl - , Br - , I - . This embodiment uses halogen ions to modify the quantum dot material. When the metal halide is mixed with the quantum dot material, the halogen ions in the metal halide replace the ligands on the surface of the quantum dot material, thereby reducing the Fermi level of the quantum dot material.

[0075] In an embodiment, the quantum dot material is blue quantum dot material or green quantum dot material. Since the energy band gap of blue quantum dot material and green quantum dot material is larger than that of red quantum dot material, the light-emitting efficiency of blue quantum dot light-emitting device and green quantum dot light-emitting device is lower at low voltage, and if the voltage is further increased, the interface charge will accumulate seriously, which will greatly affect the service life and efficiency of the device. Therefore, this embodiment uses halogen ions to replace the surface ligands of blue quantum dot material or green quantum dot material to form halogen-modified quantum dot material. The halogen ion-modified quantum dot material prepared in this embodiment has a lower Fermi level.

[0076] In another embodiment, step B2 includes the following steps:

[0077] First, after the quantum dot material is disposed on the first surface 1101, film formation treatment is performed.

[0078] Specifically, in a glove box without water and oxygen, the quantum dot material is coated on the first surface 1011 by spraying or drop coating, and then the quantum dot material is subjected to film formation treatment at 80-120 degrees Celsius, wherein the film formation treatment time is 10-30 minutes. The quantum dot material is solidified on the first surface 1011.

[0079] For example, in a specific embodiment, in a glove box without water and oxygen, quantum dot material with a concentration of 10 mg / mL is spin coated on the first surface 1011, wherein the quantum dot material is dissolved in n-octane. Next, the quantum dot material is heated at 100 degrees Celsius for 20 minutes to form solidified quantum dot material.

[0080] Secondly, a metal halide solution is disposed on the surface of the quantum dot material, and a heating treatment is performed to form the quantum dot light-emitting layer.

[0081] Specifically, in an anhydrous and anaerobic glove box, a metal halide is disposed on the solidified quantum dot material by a spin coating, spray coating or drop coating method, and the metal halide is allowed to stand on the solidified quantum dot material for 20 to 40 seconds so that the metal halide penetrates into the solidified quantum dot material. The metal halide is spin coated at a preset rotation speed of 500 to 1500 r / min so that the metal halide is uniformly distributed in the quantum dot material to replace the ligand on the surface of the quantum dot material.

[0082] For example, an ethanol solution of zinc chloride with a concentration of 0.2 mg / mL is added dropwise on the solidified quantum dot material, and the ethanol solution of zinc chloride is allowed to stand on the solidified quantum dot material for 30 seconds so that the ethanol solution of zinc chloride penetrates into the quantum dot material. Subsequently, the spin coating is performed at a rotation speed of 1000 r / min for 30 seconds to replace the ligand on the surface of the quantum dot to form the quantum dot light-emitting material with halogen modification.

[0083] It should be noted that the metal halide can also be disposed on the solidified quantum dot material by oscillation or other methods.

[0084] The metal halide is subjected to a heating treatment at a preset temperature to form the quantum dot light-emitting layer.

[0085] Specifically, the metal halide is subjected to a heating treatment at a preset temperature of 35 to 70 degrees Celsius so that the solvent evaporates to form the quantum dot light-emitting layer 102 with halogen modification, and the second heating treatment is performed for less than or equal to 10 minutes.

[0086] For example, the ethanol solution of zinc chloride is subjected to a heating treatment at 50 degrees Celsius for 5 minutes to form the quantum dot light-emitting layer 102.

[0087] In an embodiment, the metal ion in the metal halide is selected from any one of K + , Na + , Zn 2+ , and the halogen ion in the metal halide is selected from any one of Cl - , Br - , I - . This embodiment uses the halogen ion to modify the quantum dot material. Specifically, the metal halide is added dropwise on the solidified quantum dot material, and the halogen ion in the metal halide replaces the ligand on the surface of the quantum dot material, thereby reducing the Fermi level of the quantum dot material.

[0088] Step B3: sequentially forming an electron transport layer 103 and a cathode 104 on the quantum dot light emitting layer 102, the Fermi level difference between the electron transport layer 103 and the quantum dot light emitting layer 102 is less than or equal to 0.5 eV, please refer to Figure 1 .

[0089] Specifically, first, in the glove box without water and oxygen, drop the metal oxide ethanol solution on the side of the quantum dot light emitting layer 102 away from the device board 101, and spin the metal oxide ethanol solution at a speed of 2000 r / min to 4000 r / min for 20 to 40 seconds, and then heat the metal oxide ethanol solution at 60 to 100 degrees Celsius to form the electron transport layer 103. The heating time is between 20 to 40 minutes, and the concentration of the metal oxide ethanol solution is between 20 to 40 mg / mL.

[0090] Next, evaporate a layer of conductive metal as the cathode 104 on the side of the electron transport layer 103 away from the quantum dot light emitting layer 102, and the thickness of the cathode 104 is between 80 to 120 nanometers. Thus, the light emitting device 100 is formed.

[0091] In an embodiment, the Fermi level difference between the electron transport layer 103 and the quantum dot light emitting layer 102 is between 0 eV and 0.5 eV. For example, the Fermi level difference between the electron transport layer 103 and the quantum dot light emitting layer 102 is any one of 0.1 eV, 0.2 eV, 0.35 eV, 0.5 eV. By making halogen-modified quantum dot light emitting layer 102, the Fermi level of the quantum dot material is changed, so that the Fermi level between the electron transport layer 103 and the quantum dot light emitting layer 102 is matched, the potential barrier between the electron transport layer 103 and the quantum dot light emitting layer 102 is reduced, which is beneficial to the transmission of electrons from the electron transport layer 103 to the quantum dot light emitting layer 102, and improves the light emitting efficiency of the light emitting device 100.

[0092] Since the energy band gap of the blue quantum dot material and the green quantum dot material is greater than that of the red quantum dot, the light-emitting efficiency of the blue quantum dot light-emitting device and the green quantum dot light-emitting device is low at a low voltage. If the voltage is further increased, the electrons in the quantum dot light-emitting layer will spontaneously enter the electron transport layer, causing the quantum dot light-emitting layer to be positively charged, which greatly reduces the internal quantum efficiency of the quantum dot light-emitting layer. Therefore, in the embodiment, the surface ligand of the blue quantum dot material or the green quantum dot material is replaced by a halogen ion to form a halogen-modified quantum dot material. The halogen-modified quantum dot material prepared in the embodiment has a lower Fermi level. Therefore, the Fermi level of the quantum dot light-emitting layer prepared from the quantum dot material modified by the halogen ion matches that of the electron transport layer, reducing the potential barrier between the electron transport layer and the quantum dot light-emitting layer. In this way, the quantum dot light-emitting layer will not be in a positively charged state even at a low current voltage, and the light-emitting efficiency of the light-emitting device will not differ greatly from that at a high current and high voltage.

[0093] Referring to Table 1, Table 1 compares the external quantum efficiency of the light-emitting device prepared by the method provided in the embodiment with that of the light-emitting device prepared by the method in the prior art. As can be seen from Table 1, the maximum external quantum efficiency of the light-emitting device prepared by the method provided in the embodiment is 18.7%; the maximum external quantum efficiency of the light-emitting device prepared by the method in the prior art is 18.9%. However, at a current density of 10 mA / cm 2 The external quantum efficiency of the light-emitting device prepared by the method provided in the embodiment is 16.1% at a current density of 10 mA / cm 2 The external quantum efficiency of the light-emitting device provided in the embodiment is 3.22 times that of the light-emitting device in the prior art at a low current density. Therefore, by modifying the quantum dot light-emitting material and replacing the ligand on the surface of the quantum dot material with a halogen ion, the Fermi level difference between the quantum dot light-emitting layer and the electron transport layer is reduced, thereby reducing the potential barrier between the electron transport layer and the quantum dot light-emitting layer, facilitating the transfer of electrons from the electron transport layer to the quantum dot light-emitting layer, and greatly improving the light-emitting efficiency of the light-emitting device.

[0094] Table 1:

[0095]

[0096] Referring to Figure 5 The embodiment also provides a display panel. The display panel 1000 comprises an array substrate 200 and a light-emitting device 100 arranged on the array substrate 200.

[0097] The light emitting device 100 is made by the above method for making a light emitting device.

[0098] The application provides a light emitting device and a manufacturing method thereof, and a display panel. In the manufacturing method of the light emitting device, the Fermi level difference between the electron transport layer and the quantum dot light emitting layer is reduced, so that the potential barrier of the electron transport layer and the quantum dot light emitting layer is reduced, the electron transport from the electron transport layer to the quantum dot light emitting layer is facilitated, and the light emitting efficiency of the light emitting device is improved.

[0099] To sum up, although the application has disclosed the above preferred embodiments, the above preferred embodiments are not used to limit the application, and those skilled in the art can make various changes and decorations without departing from the spirit and scope of the application. Therefore, the protection scope of the application is defined by the scope of the claims.

Claims

1. A method for manufacturing a light-emitting device, characterized in that, Includes the following steps: A device board is provided, the device board having a first side and a second side disposed opposite to each other; A quantum dot light-emitting layer is formed on the first surface; An electron transport layer and a cathode are sequentially formed on the quantum dot light-emitting layer, and the Fermi level difference between the electron transport layer and the quantum dot light-emitting layer is less than or equal to 0.5 eV; The quantum dot light-emitting layer includes halogen-doped quantum dot materials, and the quantum dot materials contain cadmium, zinc, selenium and sulfur, wherein the content ratio of cadmium to zinc is greater than 1:

1. The method for preparing the quantum dot luminescent layer includes the following steps: Metal halides are mixed with the quantum dot material to form a halogen-modified quantum dot material; The halogen-modified quantum dot material is disposed on the first surface to form the quantum dot light-emitting layer; Alternatively, the method for preparing the quantum dot light-emitting layer includes the following steps: After quantum dot material is deposited on the first surface, a film-forming process is performed. A metal halide solution is disposed on the surface of the quantum dot material and subjected to heat treatment to form the quantum dot light-emitting layer; The concentration of the metal halide is less than or equal to 2 mg / mL, the concentration of the quantum dot material is between 20 mg / mL and 40 mg / mL, and the volume ratio of the metal halide to the quantum dot material is between 1:20 and 1:35; the metal ions in the metal halide are selected from K + Na + Zn 2+ Any one of the following, wherein the halide ion in the metal halide is selected from Cl... - ,Br - I - Any one of them.

2. A light-emitting device, characterized in that, The light-emitting device is manufactured using the method described in claim 1, wherein the light-emitting device comprises: A device board having a first surface and a second surface disposed opposite to each other; A quantum dot light-emitting layer is disposed on the first surface; An electron transport layer is disposed on the side of the quantum dot light-emitting layer away from the device plate.

3. The light-emitting device according to claim 2, characterized in that, The quantum dot light-emitting layer is made by modifying the surface of the quantum dot material with halogen.

4. The light-emitting device according to claim 2, characterized in that, The material of the quantum dot luminescent layer is Zn. X Cd 1-X S, Zn X Cd 1-X Se、Zn X Cd 1-X S / ZnSe, Zn X Cd 1-X Se / ZnS, Zn X Cd 1-X At least one of Se / ZnSe / ZnS, wherein X is less than 1.

5. A display panel, characterized in that, The display panel includes a light-emitting device and an array substrate as described in any one of claims 2 to 4, wherein the light-emitting device is disposed on the array substrate.

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