WO2020244252A1

WO2020244252A1 - Organic light-emitting device, display panel and display device

Info

Publication number: WO2020244252A1
Application number: PCT/CN2020/075942
Authority: WO
Inventors: 吴海东; 李彦松
Original assignee: 京东方科技集团股份有限公司
Priority date: 2019-06-05
Filing date: 2020-02-20
Publication date: 2020-12-10
Also published as: CN110148677A

Abstract

The present disclosure discloses an organic light-emitting device, a display panel and a display device. The organic light-emitting device comprises a cathode layer and an anode layer, which are arranged oppositely, and a light-emitting composite structure located between the cathode layer and the anode layer. The light-emitting composite structure is mixed with a hole-type material, an electronic material and a light-emitting doping material, wherein the proportion of the electronic material in the light-emitting composite structure at the side close to the cathode layer is greater than that of the hole-type material, and the proportion of the hole-type material in the light-emitting composite structure at the side close to the anode layer is greater than that of the electronic material.

Description

Organic electroluminescent device, display panel and display device

Cross references to related applications

This application claims the priority of Chinese Patent Application No. 201910485873.9 filed in China on June 5, 2019, the entire content of which is incorporated herein by reference.

Technical field

The present disclosure relates to the field of display technology, in particular to an organic electroluminescent device, a display panel and a display device.

Background technique

Organic Light Emitting Diode (OLED) has received great attention in the field of flat panel display and lighting due to its advantages of high brightness, saturated color, thinness, and flexibility. However, organic electroluminescent devices in the related art have problems such as brightness degradation and low current efficiency.

Summary of the invention

The embodiment of the present disclosure provides an organic electroluminescence device, including: a cathode layer and an anode layer, and a light-emitting composite structure located between the cathode layer and the anode layer; holes are mixed in the light-emitting composite structure Type materials, electronic type materials and light-emitting doped materials; wherein the proportion of the electron-type material on the side close to the cathode layer in the light-emitting composite structure is greater than the proportion of the hole-type material, and the light-emitting composite structure is close to The proportion of hole-type materials on one side of the anode layer is greater than that of electron-type materials.

Optionally, in a specific implementation, in the above-mentioned organic electroluminescent device provided by the embodiment of the present disclosure, the light-emitting composite structure includes only one light-emitting layer, and the direction along the cathode layer points to the anode layer, so The proportion of electron-type materials in the light-emitting layer gradually decreases, and the proportion of hole-type materials in the light-emitting layer gradually increases.

Optionally, in a specific implementation, in the above-mentioned organic electroluminescence device provided by the embodiment of the present disclosure, the light-emitting composite structure includes at least two light-emitting layers, and the electronic type in the outermost light-emitting layer close to the cathode layer The proportion of the material is greater than the proportion of the hole-type material, and the proportion of the hole-type material in the outermost light-emitting layer close to the anode layer is greater than the proportion of the electron-type material.

Optionally, in specific implementation, in the above-mentioned organic electroluminescent device provided by the embodiment of the present disclosure, the light-emitting composite structure includes a first light-emitting layer and a second light-emitting layer, and the first light-emitting layer is close to the cathode. Layer, the second light-emitting layer is close to the anode layer.

Optionally, in specific implementation, in the above-mentioned organic electroluminescent device provided by the embodiment of the present disclosure, the light-emitting composite structure further includes a third light-emitting layer located between the first light-emitting layer and the second light-emitting layer. For the light-emitting layer, the proportion of the electron-type material in the third light-emitting layer is equal to the proportion of the hole-type material.

Optionally, in a specific implementation, in the above-mentioned organic electroluminescent device provided by the embodiment of the present disclosure, the thickness of the first light-emitting layer and the thickness of the second light-emitting layer are the same, and the thickness of the third light-emitting layer The thickness is smaller than the thickness of the first light-emitting layer.

Optionally, in specific implementation, in the above-mentioned organic electroluminescent device provided by the embodiment of the present disclosure, the thickness of the first light-emitting layer and the second light-emitting layer are both 10nm-20nm, and the third light-emitting layer The thickness of the layer is 10nm-15nm.

Optionally, in specific implementation, in the above-mentioned organic electroluminescent device provided by the embodiment of the present disclosure, the hole-type material in each light-emitting layer is the same or different, and the electron-type material in each light-emitting layer is the same Or different.

Optionally, during specific implementation, in the above-mentioned organic electroluminescent device provided by the embodiment of the present disclosure, the light-emitting doping material in each light-emitting layer is the same.

Correspondingly, an embodiment of the present disclosure also provides a display panel, including any one of the organic electroluminescent devices provided in the embodiment of the present disclosure.

Correspondingly, an embodiment of the present disclosure also provides a display device, including the above-mentioned display panel provided by the embodiment of the present disclosure.

Description of the drawings

FIG. 1 is one of the structural schematic diagrams of an organic electroluminescent device provided by an embodiment of the disclosure;

2 is the second structural diagram of an organic electroluminescent device provided by an embodiment of the disclosure;

3 is the third structural diagram of the organic electroluminescent device provided by the embodiments of the disclosure;

4A and 4B are schematic diagrams of the structure after performing various steps when preparing the structure of the organic electroluminescent device provided by the embodiments of the disclosure.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present disclosure clearer, specific implementations of the organic electroluminescent device, display panel, and display device provided by the embodiments of the present disclosure will be described in detail below in conjunction with the accompanying drawings.

The film thickness and shape of each layer in the drawings do not reflect the true ratio of the organic electroluminescent device, and the purpose is only to illustrate the present disclosure schematically.

In the structure of an organic electroluminescence device, electrons and holes are injected from the cathode and the anode, respectively, and emit light in the light-emitting layer of the device. Therefore, the number of electrons and holes transported to the light-emitting layer plays an important role in the performance of the organic electroluminescent device. At present, there are some technical problems in the structure of organic electroluminescent devices. For example, due to the difference in the transport characteristics of electrons and holes in the light-emitting layer, the recombination center of electrons and holes may deviate from the center of the light-emitting layer. When the recombination center of electrons and holes is close to the interface of the electron blocking layer or the hole blocking layer, interface aging is more likely to occur at the interface, causing problems such as brightness degradation and low current efficiency of the organic electroluminescent device.

The organic electroluminescent device provided by the embodiments of the present disclosure, as shown in FIGS. 1 to 3, includes: a cathode layer 1 and an anode layer 2 disposed oppositely, and a light-emitting composite structure 3 located between the cathode layer 1 and the anode layer 2 The light-emitting composite structure 3 is mixed with hole-type materials, electronic-type materials and light-emitting doping materials; among them, the proportion of the electronic-type materials on the side close to the cathode layer 1 in the light-emitting composite structure 3 is greater than the proportion of the hole-type materials The proportion of the hole-type material on the side close to the anode layer 2 in the light-emitting composite structure 3 is greater than the proportion of the electron-type material.

In the organic electroluminescent device provided by the embodiments of the present disclosure, the proportion of the electron-type material on the side close to the cathode layer in the light-emitting composite structure of the organic electroluminescent device is greater than the proportion of the hole-type material. The proportion of hole-type materials on the side of the anode layer is greater than that of electron-type materials. When emitting light, the electrons in the cathode layer can be easily transported to the side of the light-emitting composite structure near the cathode layer, so that the Holes are easily transported to the side of the light-emitting composite structure close to the anode layer, thereby ensuring that the recombination position of electrons and holes is controlled within the light-emitting composite structure, and avoiding the quenching caused by the diffusion of electrons and holes to other layers. The electronic materials and hole materials at different positions in the composite structure are designed in different proportions, which can greatly reduce the probability that the recombination position of electrons and holes will deviate to the barrier layer interface, reduce the risk of deterioration at the barrier layer interface, and improve the organic conductivity The balance ability of carriers in the light-emitting device can reduce the attenuation of luminous brightness and improve the current efficiency.

Further, in specific implementation, in the above-mentioned organic electroluminescent device provided by the embodiment of the present disclosure, as shown in FIG. 1, the light-emitting composite structure 3 only includes one light-emitting layer 3', which is directed to the anode layer 2 along the cathode layer 1 The proportion of electronic materials in the light-emitting layer 3'gradually decreases, and the proportion of hole materials in the light-emitting layer gradually increases. In this way, the proportion of the electron-type material on the side close to the cathode layer 1 in the light-emitting layer 3'can be greater than the proportion of the hole-type material, and the proportion of the hole-type material on the side close to the anode layer 2 in the light-emitting layer 3'is greater than The proportion of electronic materials, when emitting light, the electrons in the cathode layer 1 can be easily transported to the side of the light-emitting layer 3'close to the cathode layer 1, and the holes in the anode layer 2 can be easily transported to the light-emitting layer 3' The side close to the anode layer 2 in order to ensure that the recombination position of electrons and holes is controlled in the light-emitting layer 3', and to avoid the quenching caused by the diffusion of electrons and holes to other layers, so by setting different positions in the light-emitting layer 3' The electronic materials and hole-type materials are designed in different proportions, which can greatly reduce the probability that the recombination position of electrons and holes will deviate to the barrier layer interface, reduce the risk of deterioration at the barrier layer interface, and increase the current carrying in the organic electroluminescent device The balance ability of the electronic components can reduce the attenuation of the luminous brightness and improve the current efficiency.

Further, in a specific implementation, in the above-mentioned organic electroluminescent device provided by the embodiment of the present disclosure, the light-emitting composite structure includes at least two light-emitting layers, and the proportion of electronic materials in the outermost light-emitting layer close to the cathode layer is greater than The proportion of hole-type materials is larger than the proportion of electron-type materials in the outermost light-emitting layer close to the anode layer. As shown in FIG. 2, the light-emitting composite structure 3 includes two light-emitting layers. Specifically, the light-emitting composite structure 3 includes a first light-emitting layer 31 and a second light-emitting layer 32. The first light-emitting layer 31 is close to the cathode layer 1, and the second light-emitting layer 32 is close to the anode layer 2. In this way, the proportion of the electronic material in the first light-emitting layer 31 can be set to be greater than the proportion of the hole-type material, and the proportion of the hole-type material in the second light-emitting layer 32 can be set to be greater than the proportion of the electronic material. Proportionally, when emitting light, the electrons in the cathode layer 1 can be easily transported into the first light-emitting layer 31, and the holes in the anode layer 2 can be easily transported into the second light-emitting layer 32, and the electrons and holes can be recombined. The location is located in the area of the first light-emitting layer 31 and the second light-emitting layer 32 to avoid the quenching caused by the diffusion of electrons and holes to other layers, greatly reduce the probability that the recombination position of electrons and holes deviate to the barrier layer interface, and reduce the deterioration at the barrier layer interface The risk of improving the balance of carriers in the organic electroluminescent device can reduce the attenuation of luminous brightness and improve the current efficiency. As shown in FIG. 3, the light-emitting composite structure 3 includes three light-emitting layers. Specifically, the light-emitting composite structure 3 includes a first light-emitting layer 31 and a second light-emitting layer 32. The first light-emitting layer 31 is close to the cathode layer 1, and the second light-emitting layer 32 is close to the anode layer 2. The light-emitting composite structure 3 also includes a third light-emitting layer 33 located between the first light-emitting layer 31 and the second light-emitting layer 32. The proportion of electronic materials in the third light-emitting layer 33 is equal to the hole type. The percentage of materials. By setting the proportion of the electron-type material in the third light-emitting layer 33 equal to the proportion of the hole-type material, the recombination position of electrons and holes can be further located in the area of the third light-emitting layer 33, avoiding electrons and holes. The quenching caused by the diffusion of holes to other layers further reduces the probability that the recombination position of electrons and holes deviates to the barrier layer interface, reduces the risk of deterioration at the barrier layer interface, and improves the balance of carriers in the organic electroluminescent device, which can Further reduce the attenuation of luminous brightness and improve current efficiency.

It should be noted that in the embodiment shown in FIG. 3 of the present disclosure, the proportion of electronic materials in the third light-emitting layer 33 is equal to the proportion of hole materials, where equal means approximately equal, and there may be a certain The deviation.

It should be noted that in the specific implementation, in the above-mentioned organic electroluminescent device provided by the embodiments of the present disclosure, the ratio of the proportion of the electron type material and the proportion of the hole type material may be a mass ratio, and each light-emitting layer The proportion of electron-type materials and the proportion of hole-type materials can be adjusted according to actual light-emitting needs.

Further, in specific implementation, in the above-mentioned organic electroluminescent device provided by the embodiment of the present disclosure, as shown in FIG. 2 and FIG. 3, the thickness of the first light-emitting layer 31 and the thickness of the second light-emitting layer 32 may be based on The electron mobility of the electronic type material and the hole mobility of the hole type material are adjusted. Generally, the greater the mobility, the correspondingly thicker the thickness of the light-emitting layer.

Further, in specific implementation, in the above-mentioned organic electroluminescent device provided by the embodiment of the present disclosure, as shown in FIGS. 2 and 3, the thickness of the first light-emitting layer 31 and the thickness of the second light-emitting layer 32 may be the same, The thickness of the third light-emitting layer 33 may be smaller than the thickness of the first light-emitting layer 31.

It should be noted that the thickness of the first light-emitting layer 31 and the thickness of the second light-emitting layer 32 in the embodiment shown in FIG. 2 and FIG. 3 of the present disclosure are the same, where the same refers to approximately the same, and there may be certain deviations. .

Further, in specific implementation, in the above-mentioned organic electroluminescent device provided by the embodiment of the present disclosure, as shown in FIG. 2 and FIG. 3, the thickness of the first light-emitting layer 31 and the second light-emitting layer 32 may both be 10 nm- 20 nm, the thickness of the third light-emitting layer 33 may be 10 nm-15 nm.

Further, in specific implementation, in the above-mentioned organic electroluminescent device provided by the embodiment of the present disclosure, as shown in FIG. 1 to FIG. 3, the hole-type material in each light-emitting layer is the same or different, that is, in each light-emitting layer The hole-type material can be the same material or different kinds of materials; the electronic materials in each light-emitting layer are the same or different, that is, the electronic materials in each light-emitting layer can be the same material or different kinds of materials. material.

Further, in specific implementation, in the above-mentioned organic electroluminescent device provided by the embodiments of the present disclosure, the hole-type material is usually an aniline compound, and the electronic-type material is usually an imidazole compound. Specifically, the hole-type material may be a compound such as triphenylamine, (biphenyl) diamine, carbazole, etc. Alternatively, the hole-type material may be: N,N'-diphenyl-[1,1'- Biphenyl]-4,4'-diamine, phenyl-[1,1'-diphenyl]-4,4'-diamine, 1,3,5-triaminobenzene, 4,4' ,4"-Tris(N,N-diphenylamino), N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4-4 '-Diamine (NPB), triphenyldiamine derivative (TPD), TPTE, 1,3,5-tris(N-3-methylphenyl-N-phenylamino)benzene (TDAB), etc. The electronic material can be a compound such as oxadiazole, imidazole, pyridinequinoline, imine, etc. Alternatively, the electronic material can be: 2-(4-diphenyl)-5-(4-tert-butylphenyl) -1,3,4-oxadiazole, 2-(4-biphenyl)-5-phenyloxadiazole (PBD), 1,3,5-tris(N-phenyl-2-benzimidazole) -2) Benzene 41, poly(1,2-vinylidenepyridine), perylene diimide, etc.

Further, in specific implementation, in the above-mentioned organic electroluminescent device provided by the embodiment of the present disclosure, as shown in FIG. 1 to FIG. 3, the light-emitting doping material in each light-emitting layer is the same, that is, the light-emitting layer in each light-emitting layer The doping material is the same material, so that monochromatic light can be emitted and a monochromatic light-emitting device can be formed.

Further, in specific implementation, in the above-mentioned organic electroluminescent device provided by the embodiment of the present disclosure, as shown in FIG. 1 to FIG. 3, it further includes a cathode layer located between the cathode layer 1 and the first light-emitting layer 31. 1 The electron injection layer 4, the electron transport layer 5, and the hole blocking layer 6 are stacked in sequence, and the hole injection layer 7 and the hole are stacked between the anode layer 2 and the second light-emitting layer 32 facing away from the anode layer 2. The hole transport layer 8 and the electron blocking layer 9. By adding the above-mentioned electron/hole injection layer, electron/hole transport layer, and electron/hole blocking layer on both sides of the light-emitting layer, all are designed to adjust the number of electrons and holes in the organic electroluminescent device structure. Through the design of the above functional layers, the energy level difference between the layers in the organic electroluminescent device is significantly reduced, the number of electrons and holes transported to the interface of the light-emitting layer is significantly increased, and the luminous efficiency is improved.

In summary, in the embodiments of the present disclosure, the light-emitting layer of the traditional organic electroluminescent device structure is prepared into 2 to 3 light-emitting layers, each light-emitting layer includes an electronic type material, a hole type material and a light-emitting doped material, each The light-emitting layer only accounts for a different proportion of electron-type materials and hole-type materials. Through such a design, it is possible to avoid device degradation and life deterioration caused by an obvious interface between the two light-emitting layers. In addition, through the design of electronic materials and hole materials with different proportions in the three layers, it is possible to greatly reduce the position of the combined light emission of electrons and holes close to the barrier interface, and reduce the risk of deterioration at the barrier interface. Therefore, each light-emitting layer in the organic electroluminescent device provided by the embodiment of the present disclosure has different electron/hole transport characteristics, thereby improving the carrier balance ability in the light-emitting layer of the organic electroluminescent device and achieving the best current efficiency. , Reduce life attenuation and other characteristics.

Further, in specific implementation, in the above-mentioned organic electroluminescent device provided by the embodiments of the present disclosure, the material of the anode layer may be indium-doped tin oxide (ITO), and the material of the cathode layer may be Mg/Ag alloy.

Further, in specific implementation, the structure of the organic electroluminescent device provided by the embodiment of the present disclosure may be a upright structure or an inverted structure, which is not specifically limited.

Further, in specific implementation, the above-mentioned organic electroluminescent device provided by the embodiments of the present disclosure has an upright structure, as shown in FIGS. 1 to 3, and further includes a layer located on the side of the anode layer 2 facing away from the cathode layer 1. The reflective layer 12, the driving circuit 11 and the base substrate 10, and the protective layer 13 on the side of the cathode layer 1 facing away from the anode layer 2.

The preparation method of the organic electroluminescent device provided in FIG. 3 of the embodiment of the present disclosure with the upright structure will be described in detail below through specific embodiments. Specifically, the preparation methods of each film layer in the organic electroluminescent device include, but are not limited to, one or more of spin coating, vapor deposition, chemical vapor deposition, physical vapor deposition, magnetron sputtering, etc. .

(1) Clean the base substrate 10, and fabricate a drive circuit 11 on the cleaned base substrate 10. The drive circuit 11 is used to light up the pixel area of the organic electroluminescent device, as shown in FIG. 4A; specifically, the substrate The substrate 10 may be a glass substrate or the like.

(2) The reflective layer 12, the anode layer 2, the hole injection layer 7, the hole transport layer 8, and the electron blocking layer are sequentially fabricated on the base substrate 10 on which the drive circuit 11 is formed by vacuum evaporation or inkjet printing. 9. The second light-emitting layer 32, the third light-emitting layer 33, the first light-emitting layer 31, the hole blocking layer 6, the electron transport layer 5, the electron injection layer 4, the cathode layer 1, and the protective layer 13, as shown in FIG. 4B.

The organic electroluminescent device shown in FIG. 4B prepared in the embodiment of the present disclosure has an upright structure. Of course, in specific implementation, an organic electroluminescent device with an inverted structure can also be prepared, specifically, an organic electroluminescent device with an inverted structure. The light-emitting device is to sequentially fabricate a driving circuit, a reflective layer, a cathode layer, an electron injection layer, an electron transport layer, a hole blocking layer, a first light-emitting layer, a third light-emitting layer, a second light-emitting layer, and an electron blocking layer on a base substrate. , Hole transport layer, hole injection layer, anode layer and protective layer; the specific preparation process of the inverted structure organic electroluminescent device can refer to the above-mentioned preparation method of the upright structure organic electroluminescent device, only the layers The order of preparation of the product has changed, so I will not elaborate on it here.

The present disclosure does not limit the light emission type of the organic electroluminescence device, such as not limited to bottom light emission or top light emission. In specific implementation, the electrodes on the light emitting side of the organic electroluminescent device in the anode layer and the cathode layer are transparent electrodes.

During specific implementation, the organic electroluminescent device provided by the embodiments of the present disclosure may also include other functional film layers well known to those skilled in the art, which will not be described in detail here.

Based on the same inventive concept, an embodiment of the present disclosure further provides a display panel, including the above-mentioned organic electroluminescent device provided by the embodiment of the present disclosure. The problem-solving principle of the display panel is similar to that of the aforementioned organic electroluminescence device. Therefore, the implementation of the display panel can refer to the implementation of the aforementioned organic electroluminescence device, and the repetitions are not repeated here.

Based on the same inventive concept, an embodiment of the present disclosure also provides a display device, including the above-mentioned display panel provided by the embodiment of the present disclosure. The problem-solving principle of the display device is similar to that of the aforementioned organic electroluminescent device. Therefore, the implementation of the display device can refer to the implementation of the aforementioned organic electroluminescent device, and the repetitive parts will not be repeated here.

The organic electroluminescent device, display panel and display device provided by the embodiments of the present disclosure, by making the light-emitting composite structure of the organic electroluminescent device the electron type material on the side close to the cathode layer account for greater proportions than the hole type material In the light-emitting composite structure, the proportion of hole-type materials on the side close to the anode layer is greater than the proportion of electron-type materials. When emitting light, the electrons in the cathode layer can be easily transferred to the side of the light-emitting composite structure near the cathode layer. , So that the holes in the anode layer are easily transported to the side of the light-emitting composite structure close to the anode layer, so as to ensure that the recombination position of electrons and holes is controlled within the light-emitting composite structure, and avoid the quenching caused by the diffusion of electrons and holes to other layers. Therefore, by designing the electron-type material and hole-type material at different positions in the light-emitting composite structure in different proportions, the probability that the recombination position of electrons and holes deviates to the barrier layer interface can be greatly reduced, and the deterioration at the barrier layer interface can be reduced. Risk, improve the balance of carriers in the organic electroluminescent device, thereby reducing the attenuation of luminous brightness and improving current efficiency.

Obviously, those skilled in the art can make various changes and modifications to the present disclosure without departing from the spirit and scope of the present disclosure. In this way, if these modifications and variations of the present disclosure fall within the scope of the claims of the present disclosure and equivalent technologies, the present disclosure also intends to include these modifications and variations.

Claims

An organic electroluminescence device, comprising: a cathode layer and an anode layer, and a light-emitting composite structure located between the cathode layer and the anode layer; the light-emitting composite structure is mixed with hole-type materials and electron-type materials And light-emitting doped materials; wherein the proportion of the electron-type material on the side close to the cathode layer in the light-emitting composite structure is greater than the proportion of the hole-type material, and the light-emitting composite structure on the side close to the anode layer The proportion of hole-type materials is greater than that of electron-type materials.
The organic electroluminescent device according to claim 1, wherein the light-emitting composite structure only includes a light-emitting layer, and the direction of the cathode layer pointing to the anode layer is along the direction of the anode layer, and the electronic material in the light-emitting layer is The proportion gradually decreases, and the proportion of the hole-type material in the light-emitting layer gradually increases.
The organic electroluminescence device according to claim 1, wherein the light-emitting composite structure includes at least two light-emitting layers, and the proportion of electron-type materials in the outermost light-emitting layer close to the cathode layer is greater than that of hole-type materials The proportion of the hole-type material in the outermost light-emitting layer close to the anode layer is greater than the proportion of the electron-type material.
4. The organic electroluminescent device of claim 3, wherein the light-emitting composite structure comprises a first light-emitting layer and a second light-emitting layer, the first light-emitting layer is close to the cathode layer, and the second light-emitting layer is close to The anode layer.
8. The organic electroluminescence device of claim 4, wherein the light-emitting composite structure further comprises a third light-emitting layer located between the first light-emitting layer and the second light-emitting layer, and the third light-emitting layer The proportion of electron-type materials is equal to the proportion of hole-type materials.
The organic electroluminescent device of claim 5, wherein the thickness of the first light-emitting layer is the same as the thickness of the second light-emitting layer, and the thickness of the third light-emitting layer is smaller than that of the first light-emitting layer. thickness.
7. The organic electroluminescent device according to claim 6, wherein the thickness of the first light-emitting layer and the second light-emitting layer are both 10nm-20nm, and the thickness of the third light-emitting layer is 10nm-15nm.
3. The organic electroluminescent device of claim 3, wherein the hole-type materials in each of the light-emitting layers are the same or different, and the electron-type materials in each of the light-emitting layers are the same or different.
8. The organic electroluminescence device of claim 3, wherein the light-emitting doping material in each of the light-emitting layers is the same.
A display panel comprising the organic electroluminescence device according to any one of claims 1-9.
A display device comprising the display panel as claimed in claim 10.