Light-emitting device and display panel

Abstract

A light-emitting device. The light-emitting device comprises a first electrode and a second electrode, and a light-emitting layer disposed between the first electrode and the second electrode. The light-emitting device further comprises a carrier generation layer and an insulating layer. The carrier generation layer is arranged between the light-emitting layer and the second electrode, and the insulating layer is arranged between the carrier generation layer and the second electrode. The first electrode is set to be transparent, and the first electrode and the second electrode are connected to an output end of an alternating-current power supply. During the positive half-cycle of the alternating-current power supply, the light-emitting layer emits light.

Description

Light-emitting device and display panel Technical Field

[0001] The present disclosure relates to the field of display technology, and in particular to a light-emitting device and a display panel. Background Art

[0002] Quantum dot light emitting diodes (QLEDs) have become a research hotspot for decades due to their market value in light sources and displays, including high efficiency, high brightness, high color purity, wide color gamut, low power consumption, and low cost.

[0003] Summary of the Invention

[0004] On the one hand, a light-emitting device is provided, which includes: a first electrode and a second electrode, and a light-emitting layer arranged between the first electrode and the second electrode; the light-emitting device also includes: a carrier generation layer and an insulating layer, the carrier generation layer is arranged between the light-emitting layer and the second electrode; the insulating layer is arranged between the carrier generation layer and the second electrode; wherein the first electrode is set to be transparent, and the first electrode and the second electrode are configured to be connected to the output end of an AC power supply; during the positive half cycle of the AC power supply, the light-emitting layer emits light.

[0005] In some embodiments, the carrier generation layer is an electron generation layer, and the conduction band energy level of the electron generation layer ranges from -2.0 eV to -4.5 eV.

[0006] In some embodiments, the difference between the work function of the material of the electron generation layer and the conduction band energy level of the electron generation layer is less than 1 eV.

[0007] In some embodiments, the electron generation layer has a reflectivity in the visible light band ranging from 20% to 100%.

[0008] In some embodiments, the material of the electron generation layer includes at least one of aluminum, gold, and silver.

[0009] In some embodiments, the material of the carrier generation layer is the same as that of the second electrode.

[0010] In some embodiments, the carrier generation layer has a thickness ranging from 5 nm to 40 nm.

[0011] In some embodiments, the dielectric constant of the material of the insulating layer ranges from 2 to 300.

[0012] In some embodiments, the material of the insulating layer includes any one of polyvinyl pyrrolidone, polyvinylidene fluoride, silicon dioxide, polystyrene, hafnium dioxide, and polymethyl methacrylate.

[0013] In some embodiments, the thickness of the insulating layer ranges from 300 nm to 800 nm.

[0014] In some embodiments, the light-emitting device further includes: a substrate; the substrate is set to be transparent, and the first electrode, the light-emitting layer, the carrier generation layer, the insulating layer and the second electrode are sequentially arranged in a direction away from the substrate.

[0015] In some embodiments, the light-emitting device further includes: a substrate; the first electrode, the light-emitting layer, the carrier generation layer, the insulating layer and the second electrode are sequentially arranged in a direction close to the substrate.

[0016] In some embodiments, the conduction band energy level of the light-emitting layer ranges from -3.5 eV to -4.2 eV, and the valence band energy level of the light-emitting layer ranges from -5.4 eV to -6.1 eV.

[0017] In some embodiments, the light-emitting layer has a thickness ranging from 10 nm to 40 nm.

[0018] In some embodiments, the light-emitting device further includes: at least one of a hole injection layer and a hole transport layer disposed between the first electrode and the light-emitting layer.

[0019] In some embodiments, the HOMO energy level of the hole transport layer ranges from -5.4 eV to -6.3 eV, and the thickness of the hole transport layer ranges from 20 nm to 40 nm.

[0020] In some embodiments, the light-emitting device further includes an electron transport layer disposed between the light-emitting layer and the carrier generation layer.

[0021] In some embodiments, the conduction band energy level of the electron transport layer ranges from -3.2 eV to -4.5 eV.

[0022] In some embodiments, the thickness of the electron transport layer is in the range of 30 nm to 50 nm.

[0023] On the other hand, a display panel is provided, comprising the light-emitting device as described in any one of the above embodiments; the display panel further comprises a pixel driving circuit, and the pixel driving circuit is used to drive the light-emitting device to emit light. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] To more clearly illustrate the technical solutions of the present disclosure, the following briefly introduces the drawings required for use in some embodiments of the present disclosure. Obviously, the drawings described below are only drawings of some embodiments of the present disclosure, and those skilled in the art can also derive other drawings based on these drawings. Furthermore, the drawings described below are schematic diagrams and are not intended to limit the actual dimensions of the products or the actual processes of the methods involved in the embodiments of the present disclosure.

[0025] FIG1 is a structural diagram of a display device according to some embodiments of the present disclosure;

[0026] FIG2 is a structural diagram of a display panel according to some embodiments of the present disclosure;

[0027] FIG3 is a structural diagram of a sub-pixel according to some embodiments of the present disclosure;

[0028] FIG4 is a structural diagram of a light emitting device according to some embodiments of the present disclosure;

[0029] FIG5 is a diagram showing the charge migration principle of a light emitting device in a positive half cycle of an alternating current according to some embodiments of the present disclosure;

[0030] FIG6 is a diagram showing the charge migration principle of a light emitting device in a negative half cycle of an alternating current according to some embodiments of the present disclosure;

[0031] FIG7 is another structural diagram of a light emitting device according to some embodiments of the present disclosure;

[0032] FIG8 is another structural diagram of a light emitting device according to some embodiments of the present disclosure;

[0033] FIG9 is a graph showing the relationship between voltage and luminous brightness of a light-emitting device according to some embodiments of the present disclosure;

[0034] FIG10 is a graph showing the relationship between frequency and luminous brightness of a light-emitting device according to some embodiments of the present disclosure;

[0035] FIG11 is a graph showing transmittance of carrier generation layers of different thicknesses in the visible light range according to some embodiments of the present disclosure;

[0036] FIG12 is an electroluminescence spectrum diagram of a light-emitting device according to some embodiments of the present disclosure;

[0037] FIG13 is another relationship curve diagram of voltage and luminous brightness of a light-emitting device according to some embodiments of the present disclosure;

[0038] FIG14 is another structural diagram of a light emitting device according to some embodiments of the present disclosure;

[0039] FIG15 is a flow chart of a method for preparing a light-emitting device according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0040] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present disclosure. Obviously, the embodiments described are only some embodiments of the present disclosure, not all embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the present disclosure.

[0041] Unless the context requires otherwise, throughout the specification and claims, the term "comprise" and its other forms, such as the third person singular form "comprises" and the present participle form "comprising", are to be interpreted as open and inclusive, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific example" or "some examples" are intended to indicate that the particular features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the particular features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0042] When describing some embodiments, the expressions "coupled" and "connected" and their derivatives may be used. The term "connected" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. The term "coupled" indicates, for example, that two or more components are in direct physical or electrical contact. The term "coupled" or "communicatively coupled" may also refer to two or more components that are not in direct contact with each other, but still cooperate or interact with each other. The embodiments disclosed herein are not necessarily limited to the contents of this document.

[0043] “At least one of A, B and C” has the same meaning as “at least one of A, B or C” and both include the following combinations of A, B and C: A only, B only, C only, the combination of A and B, the combination of A and C, the combination of B and C, and the combination of A, B and C.

[0044] “A and / or B” includes the following three combinations: A only, B only, and a combination of A and B.

[0045] As used herein, "about," "substantially," or "approximately" includes the stated value and an average value that is within an acceptable range of deviation from the particular value as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0046] As used herein, "parallel", "perpendicular", and "equal" include the situations described and situations similar to the situations described, and the range of the similar situations is within an acceptable deviation range, wherein the acceptable deviation range is as determined by a person of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the specific quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, wherein the acceptable deviation range of approximate parallelism can be, for example, a deviation within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, wherein the acceptable deviation range of approximate perpendicularity can also be, for example, a deviation within 5°. "Equal" includes absolute equality and approximate equality, wherein the acceptable deviation range of approximate equality can be, for example, that the difference between the two equals is less than or equal to 5% of either one.

[0047] It will be understood that when a layer or element is referred to as being on another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may be present therebetween.

[0048] Exemplary embodiments are described herein with reference to cross-sectional and / or plan views that are idealized exemplary drawings. In the drawings, the thickness of layers and the area of ​​regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are contemplated. Therefore, the exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but rather include deviations in shape due to, for example, manufacturing. For example, an etched region shown as a rectangle will typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of the device and are not intended to limit the scope of the exemplary embodiments.

[0049] As shown in FIG1 , some embodiments of the present disclosure provide a display device 1000. The display device 1000 provided by the embodiments of the present disclosure can be any device that displays either motion (e.g., video) or fixed (e.g., still images) and whether text or images. More specifically, it is expected that the embodiments described can be implemented in or associated with a variety of electronic devices, such as (but not limited to) mobile phones, wireless devices, personal digital assistants (PDAs), handheld or portable computers, GPS receivers / navigators, cameras, MP4 video players, video cameras, game consoles, watches, clocks, calculators, television monitors, flat-panel displays, computer monitors, automotive displays (e.g., odometer displays, etc.), navigation systems, cockpit controls and / or displays, displays of camera views (e.g., displays of rearview cameras in vehicles), electronic photographs, electronic billboards or signs, projectors, architectural structures, packaging, and aesthetic structures (e.g., displays of images of a piece of jewelry), etc.

[0050] Specifically, as shown in FIG1 , the embodiment of the present disclosure is exemplified by taking the display device 1000 as a mobile phone.

[0051] As shown in Figures 1 and 2, a display device 1000 includes a display panel 100. The display panel 100 includes a display area AA and a peripheral area BB located on at least one side of the display area AA. The display area AA is provided with a plurality of sub-pixels 20 and a plurality of signal lines. The plurality of sub-pixels 20 are arranged in the display area AA according to a specified rule. The area where each sub-pixel 20 is located is a sub-pixel area A1. The sub-pixel 20 is the smallest unit for displaying an image in the display panel 100. Each sub-pixel 20 can display a single color, such as red, green, or blue. By adjusting the brightness of different sub-pixels 20, color superposition can achieve the display of multiple colors. As shown in Figure 3, each sub-pixel 20 includes a light-emitting device 10 and a pixel driving circuit 300 for driving the light-emitting device 10 to emit light.

[0052] Exemplarily, the display panel 100 may be an OLED (Organic Light-Emitting Diode) display panel, or a Quantum Dot Light Emitting Diode (Quantum Dot Light Emitting Diode) display panel. For example, taking the display panel 100 as a QLED (Quantum Dot Light Emitting Diode) display panel, the display panel 100 includes a base substrate 40, an array substrate 30, and a light-emitting device layer stacked in sequence, wherein the array substrate 30 is provided with a plurality of pixel driving circuits 300, and the plurality of pixel driving circuits 300 may be formed in the display area AA of the display panel 100. The light-emitting device layer includes a plurality of light-emitting devices 10, and the light-emitting devices 10 are provided on a side of the pixel driving circuit 300 away from the base substrate 40.

[0053] In some embodiments, as shown in FIG3 , a light-emitting device 10 includes a first electrode 11, a light-emitting layer 13, and a second electrode 12, which are sequentially stacked. For example, the first electrode 11 is an anode, and the second electrode 12 is a cathode. The light-emitting device 10 operates on the principle that, through a circuit connected by the first and second electrodes 11 and 12, the first electrode 11 injects holes into the light-emitting layer 13, and the second electrode 12 injects electrons into the light-emitting layer 13. The resulting electrons and holes form excitons in the light-emitting layer 13, which then transition back to a ground state through radiation, emitting photons.

[0054] However, the light-emitting device 10 driven by conventional DC voltage has the following problems: (1) Since the electrons and holes inside the light-emitting device 10 driven by DC voltage continuously move in one direction and eventually recombine and emit light in the light-emitting layer 13, this will cause charges to accumulate in some areas (for example, the hole transport layer) for a long time, thereby affecting the operating life of the light-emitting device 10; (2) Since DC drive devices inevitably require power converters and rectifiers and other equipment during the integration process, this will not only cause some power loss in terms of energy, but also increase the corresponding cost.

[0055] Based on this, as shown in FIG4 , an embodiment of the present disclosure provides a light-emitting device 10 , which includes: a first electrode 11 and a second electrode 12 , and a light-emitting layer 13 disposed between the first electrode 11 and the second electrode 12 , wherein the first electrode 11 is configured to be transparent.

[0056] Exemplarily, the first electrode 11 is an anode, and the material of the anode includes any one of indium tin oxide, indium zinc oxide, and indium tin zinc oxide. By providing a transparent first electrode 11, light generated by the light-emitting layer 13 can be emitted through the first electrode 11.

[0057] Exemplarily, the second electrode 12 is a cathode, and the material of the cathode includes a metal material, and exemplary, may include at least one of gold, silver, and aluminum.

[0058] Exemplarily, the light-emitting layer 13 is a quantum dot light-emitting layer. The material of the light-emitting layer 13 may include a quantum dot body and a quantum dot ligand structure. The quantum dot body and the coordination group in the quantum dot ligand are connected by chemical bonds. The quantum dot body may include: any one of: IIB-VIA group quantum dots, IIIA-VA group quantum dots, IVA-VIA group quantum dots, core-shell structure quantum dots and ABX3 type perovskite quantum dots. In the ABX3 type perovskite quantum dots, A is CH3NH3 + (methylamine), NH2CH=NH2(formamidine) and Cs + One or more of, B is Pb 2+ and Sn 2+ One or two of the following, X is Cl - Br - and I - One or more of the ABX3 type perovskite quantum dots include CH3NH3PbBr3, CH3NH3PbCl3, CH3NH3PbI3, CsPbBr3, CsPbCl3 and CsPbI3.

[0059] Exemplarily, the IIB-VIA Group quantum dots are selected from: binary compounds such as one or more of CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, and MgS; ternary compounds such as CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, or mixtures thereof; and quaternary compounds such as HgZnTeS, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, or mixtures thereof, but are not limited thereto.

[0060] The IIIA-VA group quantum dots are selected from: binary compounds such as GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, or mixtures thereof; ternary compounds such as GaNPs, GaNAs, GaNSb, GaPAs, GaPSb, AlNPs, AlNAs, AlNSb, AlPAs, AlPSb, InNPs, InNAs, InNSb, InPAs, InPSb, or mixtures thereof; and quaternary compounds such as GaAlNPs, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNPs, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNPs, InAlNAs, InAlNSb, InAlPAs, InAlPSb, or mixtures thereof, but are not limited thereto.

[0061] Group IVA-VIA quantum dots are selected from, but are not limited to, binary compounds such as SnS, SnSe, SnTe, PbS, PbSe, PbTe, or mixtures thereof; ternary compounds such as SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, or mixtures thereof; and quaternary compounds such as SnPbSSe, SnPbSeTe, SnPbSTe, or mixtures thereof. Group IVA-VIA quantum dots are selected, for example, from elemental (mono) semiconductors such as Si, Ge, or mixtures thereof; and binary semiconductor compounds such as SiC, SiGe, and mixtures thereof.

[0062] Core-shell quantum dots are structures where one material is the core and the other is the shell. For example, a CdS / ZnS quantum dot is a quantum dot where the core is CdS and the shell is ZnS.

[0063] In some other embodiments, the quantum dot bodies may be other nanoscale materials, such as nanorods, nanosheets, etc. The components of other nanoscale materials may include at least one of CdS, CdSe, CdTe, ZnSe, InP, PbS, CuInS2, ZnO, CsPbCl3, CsPbBr3, CsPhI3, CdS / ZnS, CdSe / ZnS, ZnSe, InP / ZnS, PbS / ZnS, InAs, InGaAs, InGaN, GaNk, ZnTe, Si, Ge, and C.

[0064] For example, the material of the light-emitting layer 13 provided in the embodiment of the present disclosure is CdSe / ZnS, which is a quantum dot material widely used in the light-emitting device 10 .

[0065] In some embodiments, as shown in FIG4 , the conduction band energy level of the light-emitting layer 13 ranges from -3.5 eV to -4.2 eV, for example, the conduction band energy level of the light-emitting layer 13 is -3.5 eV, -3.6 eV, -3.7 eV, -3.8 eV, -3.9 eV, -4.0 eV, -4.1 eV, or -4.2 eV, etc., without limitation. The valence band energy level of the light-emitting layer 13 ranges from -5.4 eV to -6.1 eV, for example, the valence band energy level of the light-emitting layer 13 is -5.4 eV, -5.5 eV, -5.6 eV, -5.7 eV, -5.8 eV, -5.9 eV, -6.0 eV, or -6.1 eV, etc., without limitation.

[0066] Illustratively, the thickness of the light emitting layer 13 ranges from 10 nm to 40 nm. For example, the thickness of the light emitting layer 13 is 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm or 40 nm, etc., which is not limited here.

[0067] In some examples, as shown in FIG4 , the light-emitting device 10 further includes a carrier generation layer 15 and an insulating layer 14. The carrier generation layer 15 is disposed between the light-emitting layer 13 and the second electrode 12, and the insulating layer 14 is disposed between the carrier generation layer 15 and the second electrode 12. The first electrode 11 and the second electrode 12 are configured to be connected to an AC power supply output terminal. During the positive half cycle of the AC power supply, the light-emitting layer 13 emits light.

[0068] For example, the material of the carrier generation layer 15 includes metal. The carrier generation layer 15 is an electron generation layer that generates electrons in an alternating current environment.

[0069] As shown in Figure 5, the light-emitting principle of the light-emitting device 10 is: in the positive half cycle of the alternating current, the insulating layer 14 blocks the electrons, the electrons generated by the carrier generation layer 15 migrate to the light-emitting layer 13, the first electrode 11 injects holes, the holes migrate to the light-emitting layer 13, the electrons and holes form excitons in the light-emitting layer 13, the excitons return to the ground state through radiation transition, and emit photons.

[0070] During this process, some electrons accumulate between the second electrode 12 and the insulating layer 14. These electrons do not participate in the emission of light. As shown in FIG6 , during the negative half-cycle of the alternating current, holes migrate toward the first electrode 11, while electrons accumulated between the second electrode 12 and the insulating layer 14 migrate toward the second electrode 12.

[0071] That is, during one AC cycle, as the voltage gradually increases, the insulating layer 14 acts like a capacitor, and the capacitor's function can be divided into four stages: initial charging, continuous charging, charging completion, and discharge. Specifically, during the positive half-cycle of the AC, the capacitor undergoes three stages: initial charging, continuous charging, and charging completion. During this period, equal amounts of oppositely charged charges accumulate on both sides of the insulating layer 14. During the negative half-cycle of the AC, the capacitor discharges, and electrons accumulated between the second electrode 12 and the insulating layer 14 migrate toward the second electrode 12.

[0072] During a complete cycle of the alternating current, holes first migrate toward the light-emitting layer 13 and then migrate toward the first electrode 11. Electrons first migrate toward the insulating layer 14, accumulate between the insulating layer 14 and the second electrode 12, and then migrate toward the second electrode 12. During a complete cycle of the alternating current, the migration directions of holes and electrons change.

[0073] Therefore, the embodiment of the present disclosure provides a single-ended carrier injection type light-emitting device 10. After the electrons and holes of the light-emitting device 10 recombine and emit light in the light-emitting layer 13, they separate and move in opposite directions. This can effectively prevent the electrons and holes from continuously moving in one direction and accumulating in some areas (such as the hole transport layer) for a long time, which may affect the operating life of the light-emitting device 10, thereby improving the operating life of the light-emitting device 10.

[0074] It should be noted that a single-ended carrier injection light-emitting device 10 includes an insulating layer 14 on the first electrode 11 or the second electrode 12 to isolate the injected holes and electrons, while the alternating electric field ionizes the other side to generate holes or electrons. The light-emitting device 10 provided in the embodiments of the present disclosure includes an insulating layer 14 on the second electrode 12 to isolate the injected electrons, while the alternating electric field ionizes the first electrode 11 to generate holes.

[0075] In order to provide a light-emitting device 10 with higher luminous efficiency, the embodiment provided in the present disclosure optimizes the film structure setting of the light-emitting device 10, especially for the carrier generation layer 15 being an electron generation layer, the performance of the electron generation layer is optimized.

[0076] Specifically, in order to achieve energy level matching of each layer of the light-emitting device 10 and optimize the transmission characteristics, the film layer structure setting of the light-emitting device 10 is first introduced.

[0077] In some embodiments, as shown in FIG. 4 , the light emitting device 10 further includes at least one of a hole injection layer 18 and a hole transport layer 17 disposed between the first electrode 11 and the light emitting layer 13 .

[0078] Exemplarily, the material of the hole injection layer 18 is poly (3,4-ethylenedioxythiophene) / polystyrene sulfonate, and the thickness of the hole injection layer 18 ranges from 30 nm to 50 nm. For example, the thickness of the hole injection layer 18 is 30 nm, 35 nm, 40 nm, 45 nm or 50 nm, etc., which is not limited here.

[0079] Exemplarily, the material of the hole transport layer 17 includes: any one of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], 4-butyl-N,N-diphenylaniline homopolymer, 1,2,4,5-tetrakis(trifluoromethyl)benzene and polyvinylcarbazole. In the embodiment of the present disclosure, the material of the hole transport layer 17 is 1,2,4,5-tetrakis(trifluoromethyl)benzene for illustrative purposes.

[0080] Exemplarily, the thickness of the hole transport layer 17 ranges from 20 nm to 40 nm. For example, the thickness of the hole transport layer 17 is 20 nm, 25 nm, 30 nm, 35 nm or 40 nm, etc., which is not limited here.

[0081] Exemplarily, the HOMO (Highest Occupied Molecular Orbital) energy level of the hole transport layer 17 ranges from -5.4 eV to -6.3 eV. For example, the HOMO energy level of the hole transport layer 17 is -5.4 eV, -5.5 eV, -5.6 eV, -5.7 eV, -5.8 eV, -5.9 eV, -6.0 eV, -6.1 eV, -6.2 eV or -6.3 eV, etc., which is not limited here.

[0082] The hole injection layer 18 and / or the hole transport layer 17 can improve the hole transport efficiency of the light-emitting device 10. The HOMO energy level of the hole transport layer 17 is matched with the valence band energy level of the light-emitting layer 13, which helps to increase the migration speed of holes from the hole transport layer 17 to the light-emitting layer 13.

[0083] In some embodiments, as shown in FIG. 4 , the light-emitting device 10 further includes an electron transport layer 16 disposed between the light-emitting layer 13 and the carrier generation layer 15 .

[0084] Exemplarily, the material of the electron transport layer 16 includes: ZnO or ZnMgO. In the embodiment of the present disclosure, the material of the electron transport layer 16 is ZnMgO for exemplary description.

[0085] Exemplarily, the thickness of the electron transport layer 16 ranges from 30 nm to 50 nm. For example, the thickness of the electron transport layer 16 is 30 nm, 35 nm, 40 nm, 45 nm, or 50 nm, etc., which is not limited here.

[0086] Exemplarily, the conduction band energy level of the electron transport layer 16 ranges from -3.2eV to -4.5eV. For example, the conduction band energy level of the electron transport layer 16 is -3.2eV, -3.3eV, -3.4eV, -3.5eV, -3.6eV, -3.7eV, -3.8eV, -3.9eV, -4.2eV or -4.5eV, etc., which is not limited here.

[0087] The provision of the electron transport layer 16 can improve the electron transport efficiency of the light-emitting device 10. The conduction band energy level of the electron transport layer 16 matches the conduction band energy level of the light-emitting layer 13, which helps to increase the migration speed of electrons generated by the carrier generation layer 15 from the electron transport layer 17 to the light-emitting layer 13.

[0088] Therefore, the embodiments of the present disclosure achieve a light-emitting device 10 with optimized carrier transport performance by optimizing the materials, thicknesses, and energy levels of the various film layers of the light-emitting device 10. This results in a relatively more balanced carrier transport within the light-emitting device 10, enabling more stable emission of light in an AC power environment. For experimental data on the luminous performance of the light-emitting device 10 provided in the embodiments of the present disclosure, please refer to the subsequent description and will not be further described here.

[0089] The following is an example of setting parameters of the electron generation layer when the carrier generation layer 15 serves as the electron generation layer.

[0090] In some embodiments, as shown in FIG. 4 , the carrier generation layer 15 is an electron generation layer, and the conduction band energy level of the electron generation layer ranges from −2.0 eV to −4.5 eV.

[0091] Illustratively, the conduction band energy level of the carrier generation layer 15 is -2.0 eV, -2.2 eV, -2.4 eV, -2.6 eV, -3.0 eV, -3.3 eV, -3.9 eV, or -4.5 eV, etc., which is not limited here.

[0092] Since the energy level setting of the electron generation layer will affect the amount of electrons generated in the light-emitting device 10, by setting the conduction band energy level range of the electron generation layer to -2.0eV to -4.5eV, it can be ensured that the electron generation layer has a larger carrier concentration. Under the action of the electric field, the electron generation layer can generate more electrons, thereby improving the luminous efficiency of the light-emitting device 10.

[0093] In some embodiments, as shown in FIG. 4 , the difference between the work function of the material of the electron generation layer and the conduction band energy level of the electron generation layer is less than 1 eV.

[0094] It's important to note that the work function, also known as the work function or work function, is defined in solid-state physics as the minimum energy required to move an electron from the interior of a solid to its surface. The conduction band, in solid-state physics, refers to the energy range that theoretically allows electron movement and, therefore, conducts electricity. Since the electron generation layer generates electrons, the work function of the material is the minimum energy required to extract the electrons.

[0095] Exemplarily, the material of the electron generating layer includes at least one of aluminum, gold, and silver.

[0096] Exemplarily, the work function of the material of the electron generation layer ranges from -1.0eV to -4.5eV. For example, the work function of the material of the electron generation layer is -1.0eV, -1.5eV, -2.0eV, -2.5eV, -3.0eV, -3.5eV, -4.1eV or -4.5eV, etc., which is not limited here.

[0097] Illustratively, the difference between the work function of the material of the electron generation layer and the conduction band energy level of the electron generation layer is 0 eV, 0.1 eV, 0.3 eV, 0.4 eV, 0.6 eV, 0.8 eV or 0.9 eV, etc., which is not limited here.

[0098] By setting the difference between the work function of the material of the electron generation layer and the conduction band energy level of the electron generation layer to be less than 1eV, the work function of the material of the electron generation layer and the conduction band energy level of the electron generation layer are matched, so that the carrier generation layer 15 has a larger carrier concentration.

[0099] In some examples, as shown in FIG. 4 , the reflectivity of the carrier generation layer 15 in the visible light band ranges from 20% to 100%.

[0100] Exemplarily, the reflectivity of the carrier generation layer 15 in the visible light band is 20%, 30%, 50%, 60%, 70%, 80%, 90% or 100%, etc., which is not limited here.

[0101] By setting the reflectivity of the carrier generation layer 15 in the visible light band to be in the range of 20% to 100%, the carrier generation layer 15 can directly reflect the light emitted by the light-emitting layer 13 to increase the light emission performance of the light-emitting device 10.

[0102] For example, as shown in FIG7 , the film layer arrangement of the light-emitting device 10 includes: a first electrode 11, a hole transport layer 17, a light-emitting layer 13, an electron transport layer 16, a carrier generation layer 15, an insulating layer 14, and a second electrode 12, which are sequentially arranged on one side of the substrate 50. As shown in FIG8 , the film layer arrangement of the light-emitting device 10 differs from that of the light-emitting device 10 shown in FIG7 in that the light-emitting device 10 does not include the carrier generation layer 15. That is, the film layer arrangement of the light-emitting device 10 shown in FIG8 includes: a first electrode 11, a hole transport layer 17, a light-emitting layer 13, an electron transport layer 16, an insulating layer 14, and a second electrode 12, which are sequentially arranged on one side of the substrate 50.

[0103] As shown in FIG. 8 , the light L1 emitted by the light emitting layer 13 is reflected by the second electrode 12 to form the light L2 , and the light L2 is emitted from the first electrode 11 .

[0104] As shown in FIG7 , a portion of light L1 emitted by light emitting layer 13 is reflected by carrier generating layer 15 to form light L4, which then exits first electrode 11. Another portion of light L1, light L3, is reflected by second electrode 12 to form light L5, which then exits first electrode 11.

[0105] That is to say, by utilizing the reflection of visible light by the carrier generation layer 15, a part of the light L1 emitted by the light-emitting layer 13 is directly reflected by the carrier generation layer 15, and this part of the light does not need to pass through the insulating layer 14, which can reduce the loss of light energy, thereby significantly enhancing the light emission characteristics of the light-emitting device 10.

[0106] The following experimental data is provided regarding how the light emission performance of the light-emitting device 10 can be increased by setting the conduction band energy level of the carrier generation layer 15 and the reflection of the carrier generation layer 15 in the visible light band.

[0107] As shown in FIG7 , the film layer arrangement of the light-emitting device 10 includes: a first electrode 11 , a hole transport layer 17 , a light-emitting layer 13 , an electron transport layer 16 , a carrier generation layer 15 , an insulating layer 14 and a second electrode 12 arranged in sequence on one side of a substrate 50 .

[0108] The substrate 50 is made of glass. The material of the first electrode 11 is indium tin oxide. The material of the hole transport layer 17 is 1,2,4,5-tetrakis(trifluoromethyl)benzene, and the thickness of the hole transport layer 17 is 40 nm. The material of the light-emitting layer 13 is CdSe / ZnS. For example, the light-emitting layer 13 emits red light, and the thickness of the light-emitting layer 13 is 40 nm. The material of the electron transport layer is ZnMgO, and the thickness of the electron transport layer is 50 nm. The material of the insulating layer 14 is polyvinylidene fluoride, and the thickness of the insulating layer 14 is 550 nm. The material of the second electrode 12 is aluminum, and the thickness of the second electrode 12 is 100 nm. The material of the carrier generation layer 15 is aluminum.

[0109] Figure 9 is a graph showing the relationship between voltage and luminous brightness of the light emitting device 10. The horizontal axis represents voltage, in units of Vpp, where Vpp refers to the voltage from the lowest value to the highest value of the AC or pulse signal, also known as the peak-to-peak value. The vertical axis represents luminous brightness, in units of cd / m 2 FIG9 includes four curves showing the relationship between voltage and luminous brightness of the light emitting device 10 . In the four curves, the thickness of the carrier generation layer 15 of the light emitting device 10 is different, and the thickness of the carrier generation layer 15 is 0 nm, 5 nm, 10 nm and 20 nm respectively.

[0110] It should be noted that the thickness of the carrier generation layer 15 being 0 nm means that the carrier generation layer 15 is not provided. The structure of the light emitting device 10 without the carrier generation layer 15 can be shown in FIG. 8 .

[0111] FIG10 is a graph showing the relationship between the frequency and the luminous brightness of the light emitting device 10. The horizontal axis represents the frequency of the alternating current in KHz. The vertical axis represents the luminous brightness in cd / m 2 FIG10 includes four curves showing the relationship between the frequency and the luminous brightness of the light emitting device 10. In the four curves, the thickness of the carrier generation layer 15 of the light emitting device 10 is different, and the thickness of the carrier generation layer 15 is 0 nm, 5 nm, 10 nm and 20 nm respectively.

[0112] As can be seen from Figures 9 and 10, the luminance of the light-emitting device 10 provided with the carrier generation layer 15 is significantly greater than that of the light-emitting device 10 without the carrier generation layer 15. As can be seen from Figure 9, compared to the luminance of the light-emitting device 10 without the carrier generation layer 15, the luminance of the light-emitting device 10 provided with the carrier generation layer 15 is significantly improved, with the luminance of the light-emitting device 10 provided with the carrier generation layer 15 increasing by approximately 40%. As can be seen from Figure 10, compared to the luminance of the light-emitting device 10 without the carrier generation layer 15, the luminance of the light-emitting device 10 provided with the carrier generation layer 15 is significantly improved, with the luminance of the light-emitting device 10 provided with the carrier generation layer 15 increasing by approximately 128%. This is because the carrier concentration of the metal carrier generation layer 15 is relatively high, resulting in a significant improvement in the luminance of the light-emitting device 10 provided with the carrier generation layer 15.

[0113] As the voltage and frequency of the alternating current increase, the brightness of the light emitting device 10 provided by the embodiment of the present disclosure shows an upward trend. Moreover, under the conditions of a voltage range of 120Vpp to 160Vpp and a frequency range of 40KHz to 120KHz, the light emitting device 10 has a relatively high brightness. The brightness of the light emitting device 10 provided by the embodiment of the present disclosure can reach 1450cd / m2 .

[0114] Moreover, the electron generation concentration of carrier generation layers 15 of different thicknesses is basically the same. This is because under the alternating signal generated by the alternating current, if the applied alternating voltage and the alternating frequency are consistent, then the generated electron concentration is the same. However, as shown in Figure 9, the luminous brightness of the light-emitting device 10 with a carrier generation layer 15 thickness of 20nm is greater than the luminous brightness of the light-emitting device 10 with a carrier generation layer 15 thickness of 10nm. This is because when the thickness of the carrier generation layer 15 is 10nm, the carrier generation layer 15 has a smaller reflective effect on the light L1. When the thickness of the carrier generation layer 15 is 20nm, the reflective effect of the carrier generation layer 15 becomes more dominant, and the luminous brightness of the light-emitting device 10 continues to increase.

[0115] Figure 11 shows the transmittance of carrier generation layer 15 of varying thicknesses within the visible light range. The abscissa represents the wavelength of visible light in nm, and the ordinate represents the transmittance. The thicknesses of carrier generation layer 15 are 5 nm, 10 nm, 15 nm, and 20 nm, respectively.

[0116] As can be seen from Figure 11, as the thickness of carrier generation layer 15 increases, the transmittance of carrier generation layer 15 gradually decreases. This further shows that as the thickness of carrier generation layer 15 increases, the luminance of light-emitting device 10 increases due to the enhanced reflection effect of carrier generation layer 15 on light L1.

[0117] However, because electrons require sufficient time to propagate from the carrier generation layer 15 to the light-emitting layer 13, the polarity of the electric field changes rapidly under the alternating signal generated by the alternating current. For example, the polarity of the electric field can change within a few milliseconds. If the thickness of the carrier generation layer 15 is too large, the carriers generated by the carrier generation layer 15 may not be transported to the light-emitting layer 13, thereby adversely affecting the light emission of the light-emitting device 10.

[0118] Therefore, in some embodiments, as shown in FIG. 4 , the thickness of the carrier generation layer 15 is set to be in the range of 5 nm to 40 nm.

[0119] Illustratively, the thickness of the carrier generation layer 15 is 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, or 40 nm, etc., which is not limited here.

[0120] Figure 12 shows the electroluminescence spectrum of light-emitting device 10. The abscissa represents wavelength in nm, and the ordinate represents normalized intensity, where au represents luminescence intensity. The figure shows that the half-width of the spectrum is not significantly broadened, and the electroluminescence spectrum exhibits a very symmetrical Gaussian distribution. This indicates that the transfer process of electrons and holes between the light-emitting layer 13 and the surrounding materials is relatively balanced, and the structure of light-emitting device 10 is relatively reasonable. The peak emission wavelength of the electroluminescence spectrum of light-emitting device 10 is between approximately 600 nm and approximately 650 nm, meaning that the peak wavelength falls within the red light range.

[0121] Therefore, the embodiment of the present disclosure can be used to solve the problem of low luminous brightness of the AC luminescent quantum dot display device by providing the carrier generation layer 15 .

[0122] The following describes the arrangement of the insulating layer 14 of the light emitting device 10 .

[0123] In some examples, as shown in FIG. 4 , the dielectric constant of the material of the insulating layer 14 is in the range of 2-300.

[0124] Illustratively, the dielectric constant of the material of the insulating layer 14 is 2, 2.2, 2.9, 3, 4.2, 8, 15, 25, 32, 45, 50, 52, 58, 60, 65, 80, 120, 180, 230, 250 or 300, etc., which is not limited here.

[0125] The dielectric constant of the insulating layer 14 material is in the range of 2 to 300, so that the insulating layer 14 has good insulation performance. The larger the dielectric constant of the insulating layer 14 material, the stronger the insulating layer 14's ability to bind charges is, that is, the better the insulation performance of the material.

[0126] In some examples, as shown in FIG. 4 , the material of the insulating layer 14 includes at least one of polyvinyl pyrrolidone, polyvinylidene fluoride, silicon dioxide, polystyrene, hafnium dioxide, and polymethyl methacrylate.

[0127] For example, the dielectric constant of polyvinyl pyrrolidone is 4.2, the dielectric constant of polyvinylidene fluoride is 300, the dielectric constant of silicon dioxide is 4.5, the dielectric constant of hafnium dioxide is 21, the dielectric constant of polymethyl methacrylate is 3.7, and the dielectric constant of polystyrene is 2.6.

[0128] Polyvinyl pyrrolidone, polyvinylidene fluoride, silicon dioxide, polystyrene, hafnium dioxide and polymethyl methacrylate have strong charge binding ability and good insulation properties.

[0129] In some examples, as shown in FIG. 4 , the thickness of the insulating layer 14 ranges from 300 nm to 800 nm.

[0130] Illustratively, the thickness of the insulating layer 14 is 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, or 800 nm, etc., which is not limited here.

[0131] FIG13 is a graph showing the relationship between the voltage and the luminous brightness of the light emitting device 10. The horizontal axis represents the voltage in Vpp and the vertical axis represents the luminous brightness in cd / m 2 The insulating layer 14 is made of polyvinylidene fluoride. The different curves in Figure 13 represent the relationship between the luminance and voltage of the light-emitting device 10 formed with the insulating layer 14 at different film deposition speeds. Different film deposition speeds result in different thicknesses of the insulating layer 14. The unit of the film deposition speed of the insulating layer 14 is revolutions per minute. The higher the film deposition speed, the thinner the insulating layer 14.

[0132] As can be seen from FIG13 , when the voltage range is 100 Vpp to 120 Vpp and the film forming speed of the insulating layer 14 is 3000 rpm to 6000 rpm, the luminance of the light emitting device 10 is greater than or equal to 300 cd / m 2 . Moreover, when the film forming speed of the insulating layer 14 is 6000 rpm, the thickness of the formed insulating layer 14 is 300 nm. When the film forming speed of the insulating layer 14 is 3000 rpm, the thickness of the formed insulating layer 14 is 800 nm. Therefore, the thickness of the insulating layer 14 ranges from 300 nm to 800 nm, and a light-emitting device 10 with greater luminous brightness can be obtained. If the thickness of the insulating layer 14 is too large or too small, the luminous brightness of the light-emitting device 10 will gradually decrease as the voltage increases.

[0133] In some embodiments, as shown in FIG. 4 , the substrate 50 is transparent, and the first electrode 11 , the light-emitting layer 13 , the carrier-generating layer 15 , the insulating layer 14 and the second electrode 12 are sequentially arranged in a direction away from the substrate 50 .

[0134] Exemplarily, substrate 50 is a rigid substrate or a flexible substrate. For example, the rigid substrate is any one of glass, silicon dioxide, and quartz. The flexible substrate is any one of polyethylene terephthalate, polyethylene naphthalate, and polyimide. In the embodiments of the present disclosure, substrate 50 is exemplified as glass.

[0135] For example, as shown in FIG4 , the light-emitting device 10 further includes a hole injection layer 18, a hole transport layer 17, and an electron transport layer 16. The first electrode 11, the hole injection layer 18, the hole transport layer 17, the light-emitting layer 13, the electron transport layer 16, the carrier generation layer 15, the insulating layer 14, and the second electrode 12 are sequentially arranged in a direction away from the substrate 50. The hole injection layer 18, the hole transport layer 17, and the electron transport layer 16 are all transparent.

[0136] The above embodiment provides a bottom-emitting upright light emitting device 10. Due to the arrangement of the carrier generation layer 15 of this embodiment and the optimization of the energy level matching and transmission characteristics of each layer, the light emitting device 10 has a higher luminance.

[0137] In some embodiments, as shown in FIG. 14 , the first electrode 11 , the light-emitting layer 13 , the carrier-generating layer 15 , the insulating layer 14 , and the second electrode 12 are sequentially arranged in a direction close to the substrate 50 .

[0138] 14 , the light-emitting device 10 further includes a hole injection layer 18, a hole transport layer 17, and an electron transport layer 16. The first electrode 11, the hole injection layer 18, the hole transport layer 17, the light-emitting layer 13, the electron transport layer 16, the carrier generation layer 15, the insulating layer 14, and the second electrode 12 are sequentially arranged in a direction close to the substrate 50.

[0139] The above embodiment provides a top-emitting inverted light-emitting device 10. Due to the arrangement of the carrier generation layer 15 of this embodiment and the optimization of the energy level matching and transmission characteristics of each layer, the light-emitting device 10 has a higher luminance.

[0140] A method for preparing a light-emitting device is provided below, as shown in FIG. 4 and FIG. 15 . The method includes steps S1 to S8 .

[0141] S1 . Form a first electrode 11 on one side of the substrate 50 .

[0142] Exemplarily, the material of the substrate 50 is glass.

[0143] Exemplarily, before forming the first electrode 11 on one side of the substrate 50, the process further includes: cutting and etching glass to obtain a substrate 50 of a predetermined shape; sequentially immersing the substrate 50 in detergent, deionized water, and alcohol under ultrasonic conditions; and then treating the substrate 50 with nitrogen to evaporate the alcohol on the substrate 50. Thereafter, the substrate 50 is placed in a plasma processor and treated with ultraviolet light and ozone for approximately 120 seconds.

[0144] S2 . Form a hole injection layer 18 on a side of the first electrode 11 away from the substrate 50 .

[0145] For example, a poly (3,4-ethylenedioxythiophene) / polystyrene sulfonate solution is spin-coated on the side of the first electrode 11 away from the substrate 50 by a spin coating process, and then annealed at 120° C. for 30 minutes on a heating platform to form the hole injection layer 18 .

[0146] S3 . Forming a hole transport layer 17 on the side of the hole injection layer 18 away from the substrate 50 .

[0147] For example, a 1,2,4,5-tetrakis(trifluoromethyl)benzene solution is spin-coated on the side of the hole injection layer 18 away from the substrate 50 by a spin coating process, and then annealed on a heating platform at 130° C. for 20 minutes to form the hole transport layer 17 .

[0148] S4. Forming the light-emitting layer 13 on the side of the hole transport layer 17 away from the substrate 50.

[0149] For example, a CdSe / ZnS solution is spin-coated onto the side of the hole transport layer 17 facing away from the substrate 50 using a spin coating process, and then annealed at 75° C. for 30 minutes on a heating platform to form the light-emitting layer 13. For example, the heating platform is a glove box, and the water content and oxygen content of the glove box are <1 ppm and <1 ppm, respectively. PPM refers to the concentration of parts per million by mass.

[0150] S5 . Form an electron transport layer 16 on a side of the light emitting layer 13 away from the substrate 50 .

[0151] For example, a ZnMgO solution is spin-coated on the side of the light-emitting layer 13 away from the substrate 50 by a spin coating process, and then annealed on a heating platform at 85° C. for 25 minutes to form the electron transport layer 16 .

[0152] S6 . Forming a carrier generation layer 15 on a side of the electron transport layer 16 away from the substrate 50 .

[0153] Exemplarily, the material of the carrier generation layer 15 is aluminum.

[0154] For example, in a vacuum evaporation device, the device is evacuated to a pressure of 2×10 -4 Pa, and then the carrier generation layer 15 is formed by evaporation.

[0155] S7 . Form an insulating layer 14 on a side of the carrier generation layer 15 away from the substrate 50 .

[0156] For example, a polyvinylidene fluoride solution is spin-coated on the side of the carrier generation layer 15 away from the substrate 50 by a spin coating process, and then annealed on a heating platform at 180° C. for 40 minutes to form the insulating layer 14 .

[0157] S8. Form a second electrode 12 on a side of the insulating layer 14 away from the substrate 50.

[0158] For example, in a vacuum evaporation device, the device is evacuated to a pressure of 2×10 -4 Pa, and then the second electrode 12 is formed by evaporation.

[0159] Exemplarily, the material of the second electrode 12 is aluminum. By setting the material of the second electrode 12 to be the same as that of the carrier generation layer 15, the second electrode 12 and the carrier generation layer 15 can be formed using the same film forming process, which helps to simplify the process flow.

[0160] Exemplarily, the thickness of the second electrode 12 ranges from 100 nm to 150 nm. For example, the thickness of the second electrode 12 is 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, or 150 nm, etc., which is not limited here.

[0161] Exemplarily, the work function of the second electrode 12 is in the range of -4.1 eV to -5.1 eV. For example, the work function of the second electrode 12 is -4.1 eV, -4.2 eV, -4.3 eV, -4.4 eV, -4.5 eV, -4.6 eV, -4.9 eV, or -5.1 eV, etc., without limitation. The work function of the second electrode 12 is set in the range of -4.1 eV to -5.1 eV to enable efficient electron injection.

[0162] As shown in FIG1 , some embodiments of the present disclosure provide a display device 1000 , which includes: a display panel 100 as described in any of the above embodiments; and a driver chip for driving the display panel 100 for display.

[0163] For example, the driving chip is a driving IC, for example, the driving IC includes a source driver. For example, the driving chip is configured to provide driving signals to each sub-pixel in the display panel 100 .

[0164] The display device may be, for example, a mobile phone, a tablet computer, a personal digital assistant (PDA), an in-vehicle computer, a wearable display device, or the like. The embodiments of the present disclosure do not impose any particular restrictions on the specific form of the above-mentioned display device. The display device 1000 includes the display panel 100 provided in any of the above-mentioned embodiments. Therefore, the display device 1000 provided in the embodiments of the present disclosure has all the beneficial effects of the display panel 100 provided in any of the above-mentioned embodiments, which will not be described in detail here.

[0165] The above description is merely a specific embodiment of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any changes or substitutions that a person skilled in the art can conceive within the technical scope disclosed in the present disclosure should be included within the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims.

Claims

1. A light-emitting device, comprising: a first electrode and a second electrode, and a light-emitting layer disposed between the first electrode and the second electrode; a carrier generation layer, disposed between the light-emitting layer and the second electrode; an insulating layer, disposed between the carrier generating layer and the second electrode; The first electrode is transparent, and the first electrode and the second electrode are configured to be connected to an output end of an AC power supply; during a positive half cycle of the AC power supply, the light-emitting layer emits light.

2. The light emitting device according to claim 1, wherein The carrier generation layer is an electron generation layer, and the conduction band energy level range of the electron generation layer is -2.0 eV to -4.5 eV.

3. The light emitting device according to claim 2, wherein: The difference between the work function of the material of the electron generation layer and the conduction band energy level of the electron generation layer is less than 1 eV.

4. The light emitting device according to claim 2 or 3, wherein: The reflectivity of the electron generating layer to the visible light band ranges from 20% to 100%.

5. The light emitting device according to any one of claims 2 to 4, wherein: The material of the electron generating layer includes at least one of aluminum, gold and silver.

6. The light emitting device according to any one of claims 1 to 5, wherein: The material of the carrier generation layer is the same as that of the second electrode.

7. The light emitting device according to any one of claims 1 to 6, wherein: The thickness of the carrier generation layer ranges from 5 nm to 40 nm.

8. The light emitting device according to any one of claims 1 to 7, wherein: The dielectric constant of the material of the insulating layer ranges from 2 to 300.

9. The light emitting device according to any one of claims 1 to 8, wherein: The material of the insulating layer includes at least one of polyvinyl pyrrolidone, polyvinylidene fluoride, silicon dioxide, polystyrene, hafnium dioxide and polymethyl methacrylate.

10. The light emitting device according to any one of claims 1 to 9, wherein: The thickness of the insulating layer ranges from 300 nm to 800 nm.

11. The light emitting device according to any one of claims 1 to 10, further comprising: The substrate is set to be transparent, and the first electrode, the light-emitting layer, the carrier generating layer, the insulating layer and the second electrode are arranged in sequence along a direction away from the substrate.

12. The light emitting device according to any one of claims 1 to 10, further comprising: substrate; the first electrode, the light-emitting layer, the carrier generating layer, the insulating layer and the second electrode are sequentially arranged in a direction close to the substrate.

13. The light emitting device according to any one of claims 1 to 12, wherein: The conduction band energy level range of the light-emitting layer is -3.5 eV to -4.2 eV, and the valence band energy level range of the light-emitting layer is -5.4 eV to -6.1 eV. The light emitting device according to claim 13 , wherein: The thickness of the light-emitting layer ranges from 10 nm to 40 nm.

15. The light emitting device according to claim 13 or 14, further comprising: At least one of a hole injection layer and a hole transport layer is provided between the first electrode and the light-emitting layer, and the HOMO energy level of the hole transport layer is in the range of -5.4 eV to -6.3 eV. The light emitting device according to claim 15 , wherein: The thickness of the hole transport layer is in the range of 20 nm to 40 nm.

17. The light emitting device according to any one of claims 13 to 16, further comprising: An electron transport layer is provided between the light emitting layer and the carrier generating layer.

18. The light emitting device according to claim 17, wherein The conduction band energy level of the electron transport layer ranges from -3.2 eV to -4.5 eV.

19. The light emitting device according to claim 18, wherein The thickness of the electron transport layer is in the range of 30 nm to 50 nm.

20. A display panel comprising: The light-emitting device according to any one of claims 1 to 19; The pixel driving circuit is used to drive the light emitting device to emit light.

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