CN113054116A - Light emitting diode - Google Patents

Abstract

The invention belongs to the technical field of display, and particularly relates to a light emitting diode. The light-emitting diode provided by the invention comprises a cathode and an anode which are oppositely arranged, and a light-emitting layer arranged between the cathode and the anode, wherein the anode comprises a molybdenum source layer, a silver metal layer and a tungsten oxide layer which are sequentially stacked, and the tungsten oxide layer is arranged on one surface deviating from the light-emitting layer. The problems of discontinuous and uniform film appearance, leakage current, metal oxidation and the like caused by over-thin thickness of the conventional anode are solved, the light transmittance is high, and the conductivity, the stability and the luminous efficiency of the anode are further improved.

Description

Light emitting diode

Technical Field

The invention belongs to the field of display, and particularly relates to a light emitting diode.

Background

Quantum Dot Light Emitting Diodes (QLEDs) and Organic Light Emitting Diodes (OLEDs) are popular solid-state lighting technologies in recent years, have the advantages of low cost, Light weight, fast response speed, high color saturation and the like, have broad development prospects, and have become one of the important research directions for new-generation LED lighting.

Due to the demand for new technologies such as AR head-mounted devices, navigation devices mounted on the windshield of an automobile, and real-time medical imaging devices, research on transparent electrodes has become an important point in recent years for research on display devices. In order to improve the transparency, it is a common method to reduce the thickness of the metal electrode, however, the metal electrode is too thin, which causes a series of problems, such as discontinuous and uniform film morphology, leakage, metal oxidation, etc., and affects the stability and light emitting performance of the device.

Disclosure of Invention

The invention mainly aims to provide a light-emitting diode with good stability and excellent light-emitting performance.

In order to achieve the purpose, the invention adopts the following technical scheme:

the utility model provides a light-emitting diode, includes relative negative pole and the positive pole that sets up, sets up the negative pole with luminescent layer between the positive pole, the positive pole is including the molybdenum source layer, silver metal layer and the tungsten oxide layer that stack gradually the setting, just the tungsten oxide layer sets up and is deviating from the one side of luminescent layer.

The anode of the light-emitting diode provided by the invention comprises a molybdenum source layer, a silver metal layer and a tungsten oxide layer which are sequentially stacked, and the molybdenum source layer is arranged on the surface of the hole transport layer and/or the hole injection layer, which is deviated from the light-emitting layer. On one hand, the molybdenum source layer, the tungsten oxide layer and the silver metal layer are compounded, so that the problems of discontinuous and uniform film appearance, leakage current, metal oxidation and the like caused by over-thin thickness of the conventional transparent electrode are effectively solved; on the other hand, the molybdenum source layer has a certain hole injection effect, and the tungsten oxide layer is arranged on the surface away from the light-emitting layer, so that the molybdenum source layer faces the light-emitting layer, the hole injection into the light-emitting layer is promoted, the recombination efficiency of holes and electrons in the light-emitting layer is improved, and the light-emitting efficiency of the light-emitting diode is improved; in another aspect, the molybdenum source layer, the silver metal layer and the tungsten oxide layer are sequentially arranged, the tungsten oxide has a high refractive index, light entering the tungsten oxide layer can be gathered, radiation loss of plasmas on the surface of the silver metal layer and external coupling loss of integral luminescence are effectively inhibited, meanwhile, the molybdenum-containing material has a high reflectivity, and has an anti-reflection effect on reflected light reflected to the interface of the molybdenum source layer, so that light energy loss is reduced, the light-emitting diode is ensured to have high light transmittance, and the light-emitting efficiency of the light-emitting diode is further improved.

Drawings

FIG. 1 is a schematic view of the principle of the action between the molybdenum source layer and the tungsten oxide layer in the light emitting diode according to the embodiment of the present invention;

fig. 2 is a schematic diagram of a thin layer structure of a quantum dot light emitting diode according to an embodiment of the present invention;

fig. 3 is a schematic view of a thin layer structure of an organic light emitting diode according to an embodiment of the present invention.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The utility model provides a light-emitting diode, includes relative negative pole and the positive pole that sets up, sets up the negative pole with luminescent layer between the positive pole, the positive pole is including the molybdenum source layer, silver metal layer and the tungsten oxide layer that stack gradually the setting, just the tungsten oxide layer sets up and is deviating from the one side of luminescent layer.

According to the light-emitting diode provided by the embodiment of the invention, the anode comprises a molybdenum source layer, a silver metal layer and a tungsten oxide layer which are sequentially stacked, and the molybdenum source layer is arranged on the surface of the hole transport layer and/or the hole injection layer, which is deviated from the light-emitting layer. On one hand, the molybdenum source layer, the tungsten oxide layer and the silver metal layer are compounded, so that the problems of discontinuous and uniform film appearance, leakage current, metal oxidation and the like caused by over-thin thickness of the conventional transparent electrode are effectively solved; on the other hand, the molybdenum source layer has a certain hole injection effect, and the tungsten oxide layer is arranged on the surface away from the light-emitting layer, so that the molybdenum source layer faces the light-emitting layer, the hole injection into the light-emitting layer is promoted, the recombination efficiency of holes and electrons in the light-emitting layer is improved, and the light-emitting efficiency of the light-emitting diode is improved; in another aspect, the molybdenum source layer, the silver metal layer and the tungsten oxide layer are sequentially arranged, the tungsten oxide has a high refractive index, light entering the tungsten oxide layer can be gathered, radiation loss of plasmas on the surface of the silver metal layer and external coupling loss of integral luminescence are effectively inhibited, meanwhile, the molybdenum-containing material has a high reflectivity, and has an anti-reflection effect on reflected light reflected to the interface of the molybdenum source layer, so that light energy loss is reduced, the light-emitting diode is ensured to have high light transmittance, and the light-emitting efficiency of the light-emitting diode is further improved.

In the present specification, "away from" is similar to "away from" in sense of word interpretation. For example, the phrase "the tungsten oxide layer is provided on a surface facing away from the light-emitting layer" means that the tungsten oxide layer in the anode is not in contact with the light-emitting layer, and when the light-emitting diode is formed by stacking only the anode, the light-emitting layer, and the cathode in this order, the molybdenum source layer in the anode is in direct contact with the light-emitting layer, and the tungsten oxide layer in the anode is provided on a surface of the anode facing away from the light-emitting layer.

As an embodiment, the light emitting diode further includes: and the molybdenum source layer is arranged on the surface of the hole function layer, which is far away from the light-emitting layer. The molybdenum source layer has a certain hole injection effect, and is arranged on the surface of the hole functional layer, which is far away from the light-emitting layer, so that the molybdenum source layer is better in conductive contact with the hole functional layer, the conductivity of the light-emitting diode is integrally enhanced, and the light-emitting efficiency of the light-emitting diode is improved.

The hole function layer comprises a hole transport layer and a hole function layer. In some embodiments, the hole-functional layer comprises a hole-transport layer, and the molybdenum source layer is disposed at a surface of the hole-transport layer facing away from the light-emitting layer. In some embodiments, the hole function layer comprises a hole injection layer, and the molybdenum source layer is disposed at a surface of the hole injection layer facing away from the light-emitting layer. In some embodiments, the hole-function layer comprises a hole-transport layer disposed adjacent to the light-emitting layer and a hole-injection layer disposed at a surface of the hole-injection layer facing away from the light-emitting layer.

In one embodiment, the molybdenum source layer has a thickness of 1 to 8nm, the silver metal layer has a thickness of 15nm or less, and the tungsten oxide layer has a thickness of 30 to 60 nm. The thickness of the molybdenum source layer is adjusted to be 1-8nm, so that the light emitting path can be shortened to condense light; the thickness of the silver metal layer is adjusted to be below 15nm, so that the electrode is ensured to have good light transmittance and transparency; by adjusting the thickness of the tungsten oxide layer to be 30-60nm, the gathering of emergent light can be promoted, the silver metal layer is prevented from being oxidized quickly, and the service life of the silver metal layer is prolonged.

Specifically, the silver metal layer is a main component of the anode. Different from the existing transparent electrode, the embodiment of the invention reduces the thickness of the metal layer from 60-120nm to below 15nm and combines the metal layer with the molybdenum source layer and the tungsten oxide layer, thereby not only improving the transparency of the electrode, but also effectively solving the problems of discontinuous and uniform film appearance, current leakage, metal oxidation and the like caused by the over-thin thickness of the existing transparent electrode and improving the luminous efficiency of the device. Different from common metal electrode materials such as aluminum, copper, gold and the like, the silver has the characteristics of low extinction coefficient and high conductivity, has higher bonding strength with the molybdenum source layer and the tungsten oxide layer, has stable structure, and can be used as a transparent electrode to be applied to the technical fields of AR head-mounted equipment, navigation equipment loaded on an automobile windshield, real-time medical imaging equipment and the like. In one embodiment, the silver metal layer has a thickness of 15nm or less, which ensures high light transmittance and good transparency of the anode.

Specifically, the molybdenum source layer refers to a thin film material layer of an organic or inorganic substance containing molybdenum atoms, which has a certain hole injection effect and a high light reflectance. In the light-emitting diode, the molybdenum source layer is arranged on the surface of the hole transport layer and/or the hole injection layer, which is deviated from the light-emitting layer, so that the molybdenum source layer is better in conductive contact with the hole transport layer and/or the hole injection layer, the conductivity of the light-emitting diode is integrally enhanced, and the light-emitting efficiency of the light-emitting diode is improved. As an embodiment, the molybdenum-containing material is selected from at least one of phosphomolybdic acid (PMA), molybdenum oxide, ammonium molybdate, molybdenum acetylacetonate, and peroxymolybdic acid, and in some embodiments, the molybdenum-containing material is selected from PMA. The molybdenum-containing material has high reflectivity and has an anti-reflection effect on light reflected to the interface of the molybdenum source layer, so that most of light reflected by the tungsten oxide layer can be reflected by the molybdenum source layer again and refracted into the tungsten oxide layer, and most of light emitted by the light emitting layer can be transmitted to the outside of the light emitting secondary light, so that high light transmittance is ensured, and light energy loss is reduced. As an embodiment mode, the thickness of the molybdenum source layer is 1-8nm, and the thickness of the molybdenum source layer is adjusted within the thickness range, so that the light-emitting optical path is shortened to condense light. The thickness of the molybdenum source layer is optimized, and the conductivity, the stability and the luminous efficiency of the light-emitting diode are improved by matching with other layer structures such as a silver metal layer, a molybdenum oxide layer and the like.

Specifically, the tungsten oxide layer has a high refractive index, so that light rays entering the tungsten oxide layer can be gathered, and radiation loss of plasma on the surface of the silver metal layer and outcoupling loss of overall luminescence are effectively inhibited. In one embodiment, the tungsten oxide layer has a thickness of 30 to 80 nm. Through optimizing the thickness of tungsten oxide layer, other layer structures such as silver metal layer and molybdenum source layer of cooperation can further promote the emergent light to gather together, have effectively prevented the quick oxidation of silver metal layer to improved to a certain extent emitting diode's electric conductivity, stability and luminous efficacy.

In the light-emitting diode, a molybdenum source layer, a silver metal layer and a tungsten oxide layer are sequentially arranged, and the molybdenum source layer, the silver metal layer and the tungsten oxide layer are in synergistic action, so that on one hand, the radiation loss of plasmas on the surface of the silver metal layer and the outcoupling loss of overall luminescence are inhibited, the light transmittance is improved, and the light energy loss is reduced; on the other hand, the silver metal layer is effectively prevented from being oxidized, so that the light-emitting secondary light is stable and reliable in performance; in another aspect, the molybdenum source layer has a melting point of about 1000 ℃, the tungsten oxide layer has a melting point of 1473 ℃, and in the process of manufacturing the light emitting diode, the molybdenum source layer, the silver metal layer and the tungsten oxide layer are generally evaporated upwards from the hole transport layer and/or the hole injection layer in sequence, and the device may be irreversibly damaged due to the high temperature in the evaporation chamber when the tungsten oxide layer is evaporated. Therefore, in the embodiment of the invention, the molybdenum source layer is compounded with the tungsten oxide layer, and the molybdenum source layer is arranged on the surface of the hole transport layer and/or the hole injection layer, which is far away from the light-emitting layer, so that the heat atoms can be effectively prevented from being transferred to the lower layer through interface diffusion to influence the performance of the device, the stability and reliability of the light-emitting secondary light are ensured, and the light-emitting performance of the light-emitting secondary light in the using process is ensured. In some test examples, the anode has a film resistance of about 4.4 Ω/sq, and the light emitting diode including the anode has an average transmittance of 80% in all visible wavelengths, and thus can be used as a transparent electrode having excellent properties.

In some application embodiments, the action principle between the molybdenum source layer and the tungsten oxide layer can refer to fig. 1. Light emitted by the light emitting layer enters the molybdenum source layer through the hole transport layer and the hole injection layer, then enters the silver metal layer, and is refracted to the outside through the tungsten oxide layer. Most of light rays (solid lines) entering the silver metal layer enter the tungsten oxide layer, and the refractive index of the tungsten oxide layer is larger than that of the silver metal layer, so that the light rays entering the tungsten oxide layer gather towards the middle, and the radiation loss of plasmas on the surface of the silver metal layer and the outcoupling loss of overall luminescence are effectively inhibited; part of light (dotted line) entering the silver metal layer is reflected at the interface between the tungsten oxide layer and the silver metal layer and reflected to the direction of the molybdenum source layer, and the molybdenum-containing material has high reflectivity and has an anti-reflection effect on the light reflected to the interface of the molybdenum source layer, so that the light at the dotted line part in the graph 1 can be reflected again by the molybdenum source layer and refracted into the tungsten oxide layer, most of light emitted by the light emitting layer can be transmitted out of the light emitting diode, high light transmittance is ensured, and light energy loss is reduced.

The light emitting diode comprises a cathode and an anode which are oppositely arranged, and a light emitting layer arranged between the cathode and the anode. As an embodiment, the light emitting diode further includes: an electron functional layer disposed between the cathode and the light emitting layer. The electron function layer comprises an electron injection layer and an electron transport layer, the electron transport layer is arranged close to the light emitting layer, and the electron injection layer is arranged between the electron transport layer and the light emitting layer. In some embodiments, the light emitting diode is an inverted light emitting diode, and the cathode serves as a bottom electrode. In some embodiments, the cathode material is selected from indium tin oxide.

The type of the light emitting diode is not particularly limited in the embodiment of the present invention, and the light emitting diode may be a quantum dot light emitting diode, and may also be an organic light emitting diode.

In one embodiment, the light emitting diode is a quantum dot light emitting diode.

In some embodiments, the material of the light emitting layer is selected from at least one of group II-VI semiconductor nanocrystals, group III-V semiconductor nanocrystals, and group II-III-VI semiconductor nanocrystals. Wherein the II-VI semiconductor nanocrystal is preferably at least one of CdSe, CdS, ZnSe, CdS, PbS and PbSe; the III-V semiconductor nanocrystal is preferably InP and/or InAs; the II-III-VI semiconductor nanocrystal is preferably CuInS₂And/or AgInS₂. In some embodiments, the light emitting layer has a thickness of 25-50 nm.

In some embodiments, the electronically functional layer comprises an electron transport layer of a material selected from ZnO, TiO₂、BaTiO₃At least one of aluminum-doped zinc oxide, lithium-doped zinc oxide and magnesium-doped zinc oxide.

In some embodiments, the material of the hole transport layer is selected from at least one of Poly [ (9, 9-dioctylfluorenyl-2, 7-diyl) -co- (4,4' - (N- (p-butylphenyl)) diphenylamine) ], Poly (9-vinylcarbazole), Poly [ bis (4-phenyl) (4-butylphenyl) amine ] (Poly-TPD), and NPB. In some embodiments, the hole transport layer is about 30nm thick.

In some embodiments, the hole injection layer is made of a material selected from the group consisting of PEDOT: PSS (poly (3, 4-ethylenedioxythiophene) -poly (styrenesulfonic acid)) and PEDOT: PSS: s-MoO₃. In other embodiments, the material of the electron transport layer is selected from ZnO, TiO₂、BaTiO₃At least one of aluminum-doped zinc oxide (AZO), lithium-doped zinc oxide (LZO) and magnesium-doped zinc oxide (MZO).

In one embodiment, the light emitting diode is an organic light emitting diode.

In some embodiments, the material of the light emitting layer is selected from Ir (ppy)₃、Ir(tpy)₃、Ir(bzq)₃、Ir(thp)₃、Ir(btp)₃、Ir(acac)₃4,4' -N, N ' -dicarbazole-biphenyl and 3-phenyl-4- (1' -naphthyl) -5-phenyl-1, 2, 4-triazoleAt least one of them. In some embodiments, the light emitting layer has a thickness of 25-40nm in some embodiments.

In some embodiments, the material of the hole transport layer is selected from at least one of 1, 1-bis [4- [ N, N-di (P-tolylamino) phenyl ] cyclohexane (TAPC), poly (9-vinylcarbazole), polyparapyrrole, polyparaphenylene-ethylene, polythiophene, polyaniline, P3CT-N, and PCE-10. In some embodiments, the hole transport layer is 30-50 nm.

In some embodiments, the electronically functional layer comprises: an electron injection layer and an electron transport layer, the electron transport layer being disposed adjacent to the light emitting layer; the material of the electron injection layer is selected from bathophenanthroline doped with cesium carbonate, for example with Cs in a molar mass ratio of 5% to 10%₂CO₃Bathophenanthroline of (1); the material of the electron transport layer is at least one selected from bathophenanthroline (BPhen), C71-methyl butyrate and C60. In a further embodiment, the thickness of the electron injection layer is 3-5nm and the thickness of the electron transport layer is 50-80 nm.

The preparation process of the light emitting diode can refer to conventional operations in the field, for example, a chemical deposition method, an evaporation method, a spin coating method or a magnetron sputtering method and other methods are adopted to sequentially deposit functional film layers such as a light emitting layer, a hole transport layer, a hole injection layer, an anode and the like on a cathode, and then packaging is carried out.

As an embodiment, the light emitting diode is a quantum dot light emitting diode, please refer to fig. 2, and the preparation method includes the following steps:

s01, providing a cathode substrate made of the cathode contained in the quantum dot light-emitting diode; depositing anelectron transport layer 11 on thecathode substrate 10, wherein the material of the electron transport layer is the material of the electron transport layer of the quantum dot light-emitting diode;

s02, depositing a quantum dot light-emittinglayer 12 on theelectron transport layer 11, wherein the material of the quantum dot light-emitting layer refers to the material of the light-emitting layer of the quantum dot light-emitting diode;

s03, depositing ahole transport layer 13 on the quantum dot light-emittinglayer 12, wherein the material of the hole transport layer refers to the material of the hole transport layer of the quantum dot light-emitting diode;

s04, depositing ahole injection layer 14 on thehole transport layer 13, wherein the material of the hole injection layer refers to the material of the hole injection layer of the quantum dot light-emitting diode;

s05, depositing amolybdenum source layer 15 on thehole injection layer 14, wherein the material of the molybdenum source layer is the material of the molybdenum source layer of the quantum dot light-emitting diode;

s06, growing asilver metal layer 16 on themolybdenum source layer 15, wherein the material of the silver metal layer refers to the material of the silver metal layer of the quantum dot light-emitting diode;

s07, depositing atungsten oxide layer 17 on thesilver metal layer 16, wherein the material of the tungsten oxide layer refers to the material of the tungsten oxide layer of the quantum dot light-emitting diode;

and S08, packaging to obtain the quantum dot light-emitting diode.

As an embodiment, the light emitting diode is an organic light emitting diode, please refer to fig. 3, and the manufacturing method includes the following steps:

s11, providing a cathode substrate made of the cathode contained in the organic light-emitting diode; depositing anelectron injection layer 21 on thecathode substrate 20, wherein the material of the electron injection layer is the material of the electron injection layer of the organic light emitting diode;

s12, depositing anelectron transport layer 22 on theelectron injection layer 21, wherein the material of the electron transport layer refers to the material of the electron transport layer of the organic light emitting diode;

s13, depositing an organic light-emittinglayer 23 on theelectron transport layer 22, wherein the material of the organic light-emitting layer is the material of the light-emitting layer of the organic light-emitting diode;

s14, depositing ahole transport layer 24 on the organiclight emitting layer 23, wherein the material of the hole transport layer is the material of the hole transport layer of the organic light emitting diode mentioned above;

s15, depositing amolybdenum source layer 25 on thehole transport layer 24, the material of the molybdenum source layer being referred to the material of the molybdenum source layer of the above organic light emitting diode;

s16, growing asilver metal layer 26 on themolybdenum source layer 25, wherein the material of the silver metal layer is the material of the silver metal layer of the organic light emitting diode;

s17, depositing atungsten oxide layer 27 on thesilver metal layer 26, wherein the material of the tungsten oxide layer refers to the material of the tungsten oxide layer of the organic light-emitting diode;

and S18, packaging to obtain the organic light-emitting diode.

It is understood that, in the above preparation method, the deposition and/or growth can be performed by, but not limited to, chemical deposition, evaporation, magnetron sputtering, or the like.

In order that the details of the above-described implementation and operation of the present invention will be clearly understood by those skilled in the art, and the improved performance of a light emitting diode according to an embodiment of the present invention will be apparent, the implementation of the present invention will be illustrated by the following examples.

Example 1

The embodiment provides an inverted quantum dot light emitting diode (QLED), which specifically includes the following steps:

1. plating an AZO electronic transmission layer with the thickness of 40nm on the ITO substrate by a magnetron sputtering method;

2. spin-coating a CdSe @ ZnS quantum dot light-emitting layer with the thickness of 50nm on the electron transport layer, and then annealing at 110 ℃;

3. spin-coating a PVK hole transport layer with the thickness of 30nm on the quantum dot light-emitting layer and annealing at 90 ℃;

4. spin-coating a layer of PEDOT, PSS, s-MoO on the hole transport layer₃Hole injection layer and annealing at 85 deg.C;

5. spraying an 8nm PMA layer on the hole injection layer;

6. an Ag metal layer with the thickness of 12nm is vapor-plated on the PMA layer;

7. deposition of 50nm thick WO on Ag metal layer₃A layer;

8. and packaging to obtain the inverted quantum dot light-emitting diode.

Example 2

The embodiment provides an inverted organic Light Emitting Diode (LED), which specifically includes the following steps:

1. evaporating a 5 nm-thick BPhen electron injection layer doped with cesium carbonate with a molar mass ratio of 10%;

2. a BPhen electron transport layer with the thickness of 60nm is evaporated on the electron injection layer;

3. vapor-plating 30 nm-thick electron transport layer doped with 8% by molar mass ratio Ir (acac)₃The CBP active light emitting layer of (a);

4. evaporating a TAPC hole transport layer with the thickness of 45nm on the luminescent layer;

5. replacing mask plate, evaporating MoO with thickness of 5nm on the hole transport layer₃A layer;

6. in MoO₃An Ag metal layer with the thickness of 15nm is vapor-plated on the layer;

7. evaporating 35nm WO on Ag metal layer₃A layer;

8. and packaging to obtain the OLED device with the inverted structure.

Comparative example 1

This comparative example differs from example 2 in that: the PMA layer is omitted.

Comparative example 2

This comparative example differs from example 2 in that: omit WO₃And (3) a layer. .

The performance test of the light emitting diodes prepared in example 2 and comparative examples 1 to 2 was performed, and the results are shown in table 1, which shows that the brightness, transmittance, external quantum efficiency, and current efficiency of the light emitting diode prepared in this example are further improved.

TABLE 1

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims (11)

1. The utility model provides a light-emitting diode, includes relative negative pole and the positive pole that sets up, sets up the negative pole with the luminescent layer between the positive pole, its characterized in that, the positive pole is including the molybdenum source layer, silver metal layer and the tungsten oxide layer that stack gradually the setting, just the tungsten oxide layer sets up and is deviating from the one side of luminescent layer.

2. The led of claim 1, further comprising: and the molybdenum source layer is arranged on the surface of the hole function layer, which is far away from the light-emitting layer.

3. The light-emitting diode according to claim 2, wherein the hole function layer comprises a hole transport layer, and the molybdenum source layer is disposed on a surface of the hole transport layer facing away from the light-emitting layer;

or, the hole function layer comprises a hole injection layer, and the molybdenum source layer is arranged on the surface of the hole injection layer, which faces away from the light-emitting layer;

or, the hole function layer comprises a hole transport layer and a hole injection layer, the hole transport layer is arranged close to the light-emitting layer, and the molybdenum source layer is arranged on the surface of the hole injection layer, which is far away from the light-emitting layer.

4. The light-emitting diode of claim 1, wherein the material of the molybdenum source layer comprises at least one of phosphomolybdic acid, molybdenum oxide, ammonium molybdate, molybdenum acetylacetonate, and peroxymolybdic acid.

5. The led of claim 1, wherein the molybdenum source layer has a thickness of 1-8 nm; and/or

The thickness of the silver metal layer is less than or equal to 15 nm; and/or

The thickness of the tungsten oxide layer is 30-80 nm.

6. The light-emitting diode according to any one of claims 1 to 5, wherein the light-emitting secondary light further comprises: an electron functional layer disposed between the cathode and the light emitting layer.

7. The LED of claim 6, wherein the LED is an inverted LED, and the cathode is a bottom electrode.

8. The LED of claim 6, wherein the LED is a quantum dot LED, the electronically functional layer comprises an electron transport layer, and the electron transport layer comprises a material selected from ZnO and TiO₂、BaTiO₃At least one of aluminum-doped zinc oxide, lithium-doped zinc oxide and magnesium-doped zinc oxide.

9. The light-emitting diode according to claim 6, wherein the light-emitting diode is an organic light-emitting diode, and the electronically functional layer comprises: an electron injection layer and an electron transport layer, the electron transport layer being disposed adjacent to the light emitting layer;

the material of the electron injection layer is selected from bathophenanthroline doped with cesium carbonate, and the material of the electron transport layer is selected from at least one of bathophenanthroline, C71-methyl butyrate and C60.

10. The light-emitting diode according to any one of claims 1 to 5, wherein the light-emitting diode is a quantum dot light-emitting diode, and the material of the light-emitting layer is at least one selected from group II-VI semiconductor nanocrystals, group III-V semiconductor nanocrystals, and group II-III-VI semiconductor nanocrystals.

11. The LED according to any one of claims 1-5, wherein the LED is an organic LED, and the material of the light-emitting layer is selected from Ir (ppy)₃、Ir(tpy)₃、Ir(bzq)₃、Ir(thp)₃、Ir(btp)₃、Ir(acac)₃4,4' -N, N ' -dicarbazole-biphenyl and 3-phenyl-4- (1' -naphthyl) -5-phenyl-1, 2, 4-triazole.

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