Organic light-emitting device and display panel thereof

Abstract

The invention provides an organic light-emitting device and a display panel thereof. The organic light-emitting device comprises a light-emitting layer, an electron blocking layer and a hole blocking layer, wherein the electron blocking layer and the hole blocking layer are located on two opposite sides of the light-emitting layer; wherein the light-emitting layer is composed of a host material, a guest material and a co-doping agent; and the absolute value of the highest occupied molecular orbital energy level of the co-doping agent is between the absolute value of the highest occupied molecular orbital energy level of the electron blocking layer and the absolute value of the highest occupied molecular orbital energy level of the host material. Specifically, in the luminescent layer, the absolute value of the highest occupied molecular orbital energy level of the co-doping agent is between the absolute value of the highest occupied molecular orbital energy level of the electron blocking layer and the absolute value of the highest occupied molecular orbital energy level of the host material; the co-doping agent can be used as a hole transfer step to assist holes in entering the light-emitting layer and capture part of the holes, so that the hole accumulation amount at the interface of the electron blocking layer and the light-emitting layer is reduced, the capacitance of the organic light-emitting device is reduced, and the problem of smear and color cast is solved.

Description

Technical Field

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

[0002] Organic Light-Emitting Diode (OLED) has the advantages of high response speed, high color purity, flexibility, etc. Therefore, it has been widely used in the display field.

[0003] In the prior art, since the capacitance (CV) of the three R / G / B devices is inconsistent, the device with a large CV charges more slowly and has a lower first frame ratio; while the device with a small CV charges more quickly and has a higher first frame ratio. Therefore, there is a difference in the first frame ratio of the R / G / B devices during the lighting process, resulting in ghosting and color cast. Summary of the invention

[0004] The present application provides an organic light emitting device and a display panel thereof, which can improve the problem of smear and color cast.

[0005] In order to solve the above technical problems, the first technical solution provided by the present application is: providing an organic light-emitting device, the organic light-emitting device comprising a light-emitting layer and an electron blocking layer and a hole blocking layer located on opposite sides of the light-emitting layer;

[0006] The light-emitting layer is composed of a host material, a guest material and a co-dopant; and the absolute value of the highest occupied molecular orbital energy level of the co-dopant is between the absolute value of the highest occupied molecular orbital energy level of the electron blocking layer and the absolute value of the highest occupied molecular orbital energy level of the host material.

[0007] In one embodiment, the absolute value of the highest occupied molecular orbital energy level of the co-dopant is between the absolute value of the highest occupied molecular orbital energy level of the guest material and the absolute value of the highest occupied molecular orbital energy level of the host material;

[0008] And the absolute value of the highest occupied molecular orbital energy level of the guest material is greater than the absolute value of the highest occupied molecular orbital energy level of the electron blocking layer.

[0009] In one embodiment, the absolute value of the lowest unoccupied molecular orbital energy level of the co-dopant is smaller than the absolute value of the lowest unoccupied molecular orbital energy level of the host material and smaller than the absolute value of the lowest unoccupied molecular orbital energy level of the guest material.

[0010] In one embodiment, the absolute value of the lowest unoccupied molecular orbital energy level of the host and guest materials and the co-dopant is greater than the absolute value of the lowest unoccupied molecular orbital energy level of the electron blocking layer; and the absolute value of the highest occupied molecular orbital energy level of the host and guest materials and the co-dopant is less than the absolute value of the highest occupied molecular orbital energy level of the hole blocking layer.

[0011] In one embodiment, the absolute value of the triplet energy level of the co-dopant is greater than the absolute value of the triplet energy level of the host material.

[0012] In one embodiment, the doping ratio of the co-dopant is 0.4 wt %-1 wt %.

[0013] In one embodiment, the doping ratio of the guest material is 5wt%-12wt%.

[0014] In one embodiment, the co-dopant and the guest material are uniformly distributed in the light-emitting layer.

[0015] In one embodiment, the organic light emitting device further comprises:

[0016] A hole transport layer, disposed on a side of the electron blocking layer away from the light-emitting layer;

[0017] A hole injection layer is disposed on a side of the hole transport layer away from the light-emitting layer;

[0018] An electron transport layer is disposed on the side of the hole blocking layer away from the light-emitting layer;

[0019] The electron injection layer is disposed on a side of the electron transport layer away from the light emitting layer.

[0020] In order to solve the above technical problems, the first technical solution provided in the present application is: providing a display panel, wherein the display panel comprises any one of the organic light-emitting devices described above.

[0021] The beneficial effects of the present application are different from those of the prior art. In the organic light-emitting device and its display panel provided by the present application, the organic light-emitting device includes a light-emitting layer and an electron blocking layer and a hole blocking layer located on opposite sides of the light-emitting layer; wherein the light-emitting layer is composed of a host material, a guest material and a co-dopant; and the absolute value of the highest occupied molecular orbital energy level of the co-dopant is between the absolute value of the highest occupied molecular orbital energy level of the electron blocking layer and the absolute value of the highest occupied molecular orbital energy level of the host material. Specifically, by setting the absolute value of the highest occupied molecular orbital energy level of the co-dopant in the light-emitting layer between the absolute value of the highest occupied molecular orbital energy level of the electron blocking layer and the absolute value of the highest occupied molecular orbital energy level of the host material, the co-dopant can serve as a hole transfer ladder to assist holes to enter the light-emitting layer and capture some holes, thereby reducing the amount of hole accumulation at the interface between the electron blocking layer and the light-emitting layer, reducing the capacitance of the organic light-emitting device, and thereby improving the problem of smear and color cast. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0023] Figure 1 A partial structural schematic diagram of an embodiment of an organic light-emitting device provided in the present application;

[0024] Figure 2 for Figure 1 Schematic diagram of energy levels of the organic light-emitting device shown;

[0025] Figure 3 A partial structural schematic diagram of another embodiment of the organic light-emitting device provided in the present application;

[0026] Figure 4 for Figure 3 Schematic diagram of energy levels of the organic light-emitting device shown;

[0027] Figure 5 A schematic structural diagram of an embodiment of a display panel provided in the present application;

[0028] Figure 6 A partial structural schematic diagram of an embodiment of a display panel provided in the present application;

[0029] Figure 7 A schematic diagram of the film layer structure of an embodiment of a display panel provided in the present application. DETAILED DESCRIPTION

[0030] The terms "first", "second", "third" in this application are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first", "second", "third" can expressly or implicitly include at least one of the features. In the description of this application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. In the embodiments of this application, all directional indications (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication also changes accordingly. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the steps or units listed, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or devices.

[0031] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0032] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0033] See also Figure 1 and Figure 2 , Figure 1 A partial structural schematic diagram of an embodiment of an organic light-emitting device provided in the present application; Figure 2 for Figure 1 Schematic diagram of the energy levels of the organic light-emitting device shown.

[0034] The present application provides an organic light-emitting device, which includes a light-emitting layer 10 and an electron blocking layer 20 and a hole blocking layer 30 located on opposite sides of the light-emitting layer 10 .

[0035] Among them, the function of the electron blocking layer 20 is to prevent electrons from being directly injected from the cathode of the display panel into the hole transport layer 40, thereby reducing the expansion of the effective recombination area of ​​electron-hole pairs, avoiding unnecessary current leakage at the edge of the device or non-luminous area, and improving the luminous efficiency and color purity.

[0036] Among them, the position and function of the hole blocking layer 30 are opposite to those of the electron blocking layer 20. The function of the hole blocking layer 30 is to prevent holes from diffusing from the anode side of the display panel to the electron transport layer 60, and prevent holes and electrons from prematurely recombining in the non-luminous area, thereby improving the luminous efficiency and color stability of the device.

[0037] Among them, the light-emitting layer 10 is "G-EML (Green-EML)". Compared with EML that simply uses self-luminous small molecules or polymers, G-EML utilizes the advantages of the guest-host system to improve the stability of doping concentration, enhance light extraction efficiency, and improve device life.

[0038] Among them, compared with the light-emitting layer 10 in the prior art including the main material GH and the guest material GD, in the embodiment of the present application, the light-emitting layer 10 also includes a co-dopant CD, that is, the light-emitting layer 10 is composed of the main material GH, the guest material GD and the co-dopant CD; wherein the absolute value of the highest occupied molecular orbital energy level (i.e., the HOMO energy level) of the co-dopant CD is between the absolute value of the highest occupied molecular orbital energy level of the electron blocking layer 20 and the absolute value of the highest occupied molecular orbital energy level of the main material GH.

[0039] Specifically, by setting the light-emitting layer 10, the absolute value of the highest occupied molecular orbital energy level of the co-dopant CD is between the absolute value of the highest occupied molecular orbital energy level of the electron blocking layer 20 and the absolute value of the highest occupied molecular orbital energy level of the main material GH, specifically, the absolute value of the highest occupied molecular orbital energy level of the co-dopant CD is greater than the absolute value of the highest occupied molecular orbital energy level of the electron blocking layer 20, and less than the absolute value of the highest occupied molecular orbital energy level of the main material GH; thus, the co-dopant CD can serve as a hole transfer step to assist holes to enter the light-emitting layer 10 and capture some holes, thereby reducing the amount of hole accumulation at the interface between the electron blocking layer 20 and the light-emitting layer 10, reducing the capacitance of the organic light-emitting device, and thereby improving the problem of smear and color cast.

[0040] Taking the existing organic light-emitting devices as an example, which are divided into red organic light-emitting devices, green organic light-emitting devices and blue organic light-emitting devices, since the capacitance of red organic light-emitting devices, green organic light-emitting devices and blue organic light-emitting devices is inconsistent, the capacitance of red organic light-emitting devices and blue organic light-emitting devices is smaller, so they charge faster and have a higher frame ratio, while the capacitance of green organic light-emitting devices is larger, so they charge slower and have a lower frame ratio. Therefore, organic light-emitting devices of different colors have different first frame ratios during the lighting process. Specifically, in the first frame, the brightness of the green organic light-emitting device is lower than that of the stable frame, while the brightness of the red organic light-emitting device and the blue organic light-emitting device is relatively high, resulting in the first frame color being reddish. Then, when the low grayscale picture is dragged, the subjective visual effect is reddish, the human eye recognition is high, and the subjective visual effect is poor. This is called the ghosting and color cast problem.

[0041] To solve the above problems, the present application further adds a co-dopant CD into the light-emitting layer 10, for example, a co-dopant CD is added into the light-emitting layer 10 in a green organic light-emitting device. The co-dopant CD can serve as a hole transfer step in the green organic light-emitting device to assist holes in entering the light-emitting layer 10 and capture some holes, thereby reducing the amount of hole accumulation at the interface between the electron blocking layer 20 and the light-emitting layer 10, reducing the capacitance of the green organic light-emitting device, and thereby reducing the capacitance difference between the red organic light-emitting device, the green organic light-emitting device and the blue organic light-emitting device. In the first frame, the light emission consistency of the red organic light-emitting device, the green organic light-emitting device and the blue organic light-emitting device is improved, and the problem of smear and color cast is improved.

[0042] In other embodiments, the co-dopant CD may be added to the light-emitting layer 10 of the red organic light-emitting device, the green organic light-emitting device, and the blue organic light-emitting device. By adjusting the doping ratio of the co-dopant CD in the light-emitting layer 10 of different colors, the capacitance of the organic light-emitting devices of different colors can be made basically consistent, thereby avoiding the problem of different first frame proportions of organic light-emitting devices of different colors during the lighting process, which leads to the problem of smear and color cast.

[0043] For ease of description, the embodiments of the present application take a green organic light-emitting device as an example.

[0044] Please continue to see Figure 2In one embodiment, in the light-emitting layer 10, the absolute value of the highest occupied molecular orbital energy level of the co-dopant CD is also between the absolute value of the highest occupied molecular orbital energy level of the guest material GD and the absolute value of the highest occupied molecular orbital energy level of the host material GH. Specifically, the absolute value of the highest occupied molecular orbital energy level of the co-dopant CD is smaller than the absolute value of the highest occupied molecular orbital energy level of the host material GH, and greater than the absolute value of the highest occupied molecular orbital energy level of the guest material GD, and the absolute value of the highest occupied molecular orbital energy level of the guest material GD is greater than the absolute value of the highest occupied molecular orbital energy level of the electron blocking layer 20. In this way, the co-dopant can capture a small amount of holes, but will not capture holes excessively, and will not affect the recombination of holes with electrons in the light-emitting layer.

[0045] Please continue to see Figure 2 In one embodiment, the absolute value of the lowest unoccupied molecular orbital energy level (i.e., LUMO energy level) of the co-dopant CD is smaller than the absolute value of the lowest unoccupied molecular orbital energy level of the host material GH, and smaller than the absolute value of the lowest unoccupied molecular orbital energy level of the guest material GD. Specifically, by setting the absolute value of the lowest unoccupied molecular orbital energy level of the co-dopant CD to be smaller than the absolute value of the lowest unoccupied molecular orbital energy level of the host material GH, and smaller than the absolute value of the lowest unoccupied molecular orbital energy level of the guest material GD, it is possible to prevent electrons from being captured by the co-dopant CD, avoid affecting the capture of electrons by the host and guest materials, and thus avoid affecting the device efficiency.

[0046] Please continue to see Figure 2 In one embodiment, the absolute value of the lowest unoccupied molecular orbital energy level of the host, guest and co-dopant CD is greater than the absolute value of the lowest unoccupied molecular orbital energy level of the electron blocking layer 20; and the absolute value of the highest occupied molecular orbital energy level of the host, guest material and co-dopant is less than the absolute value of the highest occupied molecular orbital energy level of the hole blocking layer 30. In this way, electrons and holes are confined in the light-emitting layer, and the probability of electron-hole recombination is increased.

[0047] Furthermore, in one embodiment, the absolute value of the triplet energy level of the co-dopant CD is greater than the absolute value of the triplet energy level of the host material GH, thereby preventing energy from being transferred from the host material GH to the co-dopant CD, thereby affecting the process of energy being transferred from the host material GH to the guest material GD, resulting in deterioration of device efficiency.

[0048] Among them, in the above embodiments, the host material GH is used to carry the guest material GD and assist it in emitting light. The selection of the host material GH directly affects the key performances of the device, such as the luminous efficiency, color purity, and service life. Specifically, the types of the host material GH include, but are not limited to, aromatic amine compounds; carbazole derivatives; fluorene compounds; pyridine, pyrazoline and oxadiazole derivatives; condensed ring aromatic compounds, etc. In the embodiments of the present application, the types of the host material GH include, but are not limited to, one or more of mCBPP (3,3'-di(9H-carbazole-9-yl)-1,1'-biphenyl), mCP (9,9'-dicarbazolyl-3,5-diphenyl), TCTA (4,4',4"-tri(carbazole-9-yl)triphenylamine), DMQA (N,N'-dimethylquinacridone), and TPA (tri-n-propylamine).

[0049] Among them, the guest material GD plays a key role in luminescence, and they are doped into the main material GH to adjust and enhance the luminescence characteristics of the device. Specifically, the guest material GD includes a fluorescent material or a phosphorescent material. In the embodiment of the present application, the types of guest materials GD include but are not limited to 4CzIPNN (2,4,5,6-tetrakis (9-carbazolyl) -isophthalonitrile), 4CzTPN (2,3,5,6-tetrakis (9-carbazolyl) -terephthalonitrile), TADF (thermally excited delayed fluorescence), ADN ((9,10-bis (1-naphthyl) anthracene), DPVBi (4,4'-bis (2,2-diphenylethylene) -1,1'-biphenyl) one or more.

[0050] Among them, the material of the co-dopant CD can be selected from one or more of the types of the main material GH or the guest material GD. As long as the absolute value of the highest occupied molecular orbital energy level of the co-dopant CD is between the absolute value of the highest occupied molecular orbital energy level of the electron blocking layer 20 and the absolute value of the highest occupied molecular orbital energy level of the main material GH, it can serve as a hole transfer step to assist holes to enter the light-emitting layer 10 and capture some holes, thereby reducing the amount of hole accumulation at the interface between the electron blocking layer 20 and the light-emitting layer 10 and reducing the capacitance of the organic light-emitting device. No limitation is made here.

[0051] In one embodiment, the doping ratio of the co-dopant CD is 0.4wt%-1wt%. For example, the doping ratio of the co-dopant CD may be 0.4wt%, 0.6wt%, 0.8wt% or 1wt%. It can be understood that the doping ratio of the co-dopant CD is associated with the size of reducing the capacitance of the organic light-emitting device. In the present application, as long as the specific doping ratio of the co-dopant CD can reduce the capacitance of the organic light-emitting device using the co-dopant CD, so that the capacitance of organic light-emitting devices of different colors is basically the same, it is not limited here.

[0052] Furthermore, in the embodiment of the present application, the co-dopant CD and the guest material GD are uniformly distributed in the light-emitting layer 10 to avoid affecting the light-emitting efficiency of the device.

[0053] Specifically, experiments have found that if the doping concentrations of the co-dopant CD and the guest material GD in the light-emitting layer 10 are not uniform, although the hole injection will be improved to a certain extent, the luminous efficiency of the device will also be reduced.

[0054] In one embodiment, the doping ratio of the guest material GD is 5wt%-12wt%. For example, the doping ratio of the guest material GD can be 5wt%, 7wt%, 9wt% or 12wt%. Specifically, the doping ratio of the guest material GD is related to the type of the guest material GD. In some high-efficiency phosphorescent organic light-emitting devices, the guest material GD often adopts a lower doping ratio to reduce the self-quenching effect while ensuring efficient triplet exciton utilization. For some fluorescent organic light-emitting devices, the doping ratio of the guest material GD may be higher because there are spin statistical limitations in the fluorescence process, and more luminescence centers are required to improve the quantum efficiency.

[0055] Specifically, the organic light-emitting device provided by the present application is configured such that the absolute value of the highest occupied molecular orbital energy level of the co-dopant CD in the light-emitting layer 10 is between the absolute value of the highest occupied molecular orbital energy level of the electron blocking layer 20 and the absolute value of the highest occupied molecular orbital energy level of the main material GH. In this way, the co-dopant CD can serve as a hole transfer step to assist holes in entering the light-emitting layer 10 and capture some holes, thereby reducing the amount of hole accumulation at the interface between the electron blocking layer 20 and the light-emitting layer 10, reducing the capacitance of the organic light-emitting device, and thereby improving the problem of smear and color cast.

[0056] See also Figure 3 and Figure 4 , Figure 3 A partial structural schematic diagram of another embodiment of the organic light-emitting device provided in the present application; Figure 4 for Figure 3 Schematic diagram of the energy levels of the organic light-emitting device shown.

[0057] In some embodiments, the organic light emitting device further includes a hole transport layer 40 , a hole injection layer 50 , an electron transport layer 60 , and an electron injection layer 70 .

[0058] Among them, the hole transport layer 40 is arranged on the side of the electron blocking layer 20 away from the light-emitting layer 10; the hole injection layer 50 is arranged on the side of the hole transport layer 40 away from the light-emitting layer 10; the electron transport layer 60 is placed on the side of the hole blocking layer 30 away from the light-emitting layer 10; the electron injection layer 70 is arranged on the side of the electron transport layer 60 away from the light-emitting layer 10.

[0059] The absolute values ​​of the highest occupied molecular orbital energy levels of the hole injection layer 50 , the hole transport layer 40 , the electron blocking layer 20 , the light emitting layer 10 , the hole blocking layer 30 , the electron transport layer 60 and the electron injection layer 70 increase in sequence.

[0060] Specifically, the working principle of the light-emitting layer 10 generally includes four steps: carrier injection, carrier transport, exciton generation, and radiative luminescence. Specifically, under the drive of the external electric field, the carrier injection link includes electrons injected from the cathode into the electron injection layer 70, and holes injected from the anode into the hole injection layer 50; the carrier transport link includes electrons injected from the electron injection layer 70 into the electron transport layer 60, and finally transported to the light-emitting layer 10, and holes injected from the hole injection layer 50 into the hole transport layer 40, and finally transported to the light-emitting layer 10; the exciton generation link occurs in the light-emitting layer 10, and electrons and holes recombine to generate excitons; the radiative luminescence link includes the excitons in the light-emitting layer 10 radiatively transitioning back to the ground state and emitting light.

[0061] See also Figure 5 , Figure 5 This is a schematic diagram of the structure of an embodiment of a display panel provided by the present application. The present application also provides a display panel 1000, which can be applied to mobile phones, televisions, tablet computers, notebook computers, smart wearable devices, etc.

[0062] The display panel 1000 includes a plurality of organic light-emitting devices 100 arranged in an array, wherein the organic light-emitting device 100 is an organic light-emitting device provided by any of the above embodiments. Specifically, by setting the display panel 1000 to include the organic light-emitting device 100, the capacitance of the organic light-emitting devices 100 of different colors in the display panel 1000 is basically the same, thereby avoiding the problem of smear and color cast caused by the difference in the first frame proportion of the organic light-emitting devices 100 of different colors during the lighting process, thereby improving the subjective visual effect of the display panel 1000 and improving the user experience.

[0063] See also Figure 6 , Figure 6 A partial structural diagram of an embodiment of a display panel provided in the present application. In one embodiment, the display panel 1000 further includes an anode 200 and a cathode 300 located on both sides of the light-emitting layer 10, wherein the anode 200 is located on the side of the hole injection layer 50 away from the light-emitting layer 10, and the cathode 300 is located on the side of the electron injection layer 70 away from the light-emitting layer 10.

[0064] Specifically, under the drive of the external electric field, the anode 200 is used to inject holes into the hole injection layer 50; the cathode 300 is used to inject electrons into the electron injection layer 70, and the electrons and holes are finally transferred to the light-emitting layer 10 to recombine and generate excitons, and the excitons radiatively transition back to the ground state, thereby causing the organic light-emitting device 100 to emit light.

[0065] See also Figure 7 , Figure 7 The schematic diagram of the film layer structure of an embodiment of the display panel provided in the present application is as follows: In an embodiment, the display panel 1000 further includes a substrate 400 , a driving circuit layer 500 , a pixel definition layer 600 and an encapsulation layer 700 .

[0066] The substrate 400 plays a supporting role in the display panel 1000, and can be a flexible substrate or a rigid substrate. When the substrate 400 is a flexible substrate, its material can be polyimide (PI), or it can also be a multilayer structure in which organic layers and inorganic layers are alternately stacked; when the substrate 400 is a rigid substrate, its material can be glass or metal. The present application does not limit the structure of the substrate 400.

[0067] The driving circuit layer 500 includes a pixel driving circuit for driving the organic light-emitting device 100 to emit light, wherein the pixel driving circuit can be, for example, a 2T1C circuit, a 7T1C circuit, a 7T2C circuit or a 9T1C circuit, and the present application does not limit its specific structure.

[0068] The plurality of organic light-emitting devices 100 arranged in an array are disposed in a pixel definition layer 600. Specifically, the pixel definition layer 600 may be formed of an organic material such as polyimide (PI), polyamide, benzocyclobutene (BCB), acrylic resin or phenolic resin, or an inorganic material such as SiNx. In one embodiment, the material of the pixel definition layer 600 includes a light-absorbing material, which can prevent the light emitted by adjacent organic light-emitting devices 100 from crosstalk.

[0069] Among them, the encapsulation layer 700 is used to prevent external moisture and oxygen from affecting the organic light-emitting device 100 and the film layers such as the driving circuit layer 500. The encapsulation layer 700 includes a plurality of inorganic encapsulation film layers and at least one organic encapsulation film layer stacked together. The at least one organic encapsulation film layer is arranged between the plurality of inorganic encapsulation film layers, and the plurality of inorganic encapsulation films form a closed space that seals the organic encapsulation film layer. As an embodiment, the inorganic encapsulation film layers and the organic encapsulation film layers can be stacked alternately, and the inorganic encapsulation film layers can be set as the top and bottom layers of the encapsulation unit. The outermost inorganic encapsulation film layer can completely cover the organic encapsulation film layer, thereby forming a barrier space that can prevent water and oxygen from entering.

[0070] The above is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. An organic light-emitting device, characterized in that: The organic light emitting device comprises a light emitting layer and an electron blocking layer and a hole blocking layer located on opposite sides of the light emitting layer; The light-emitting layer is composed of a host material, a guest material and a co-dopant; and the absolute value of the highest occupied molecular orbital energy level of the co-dopant is between the absolute value of the highest occupied molecular orbital energy level of the electron blocking layer and the absolute value of the highest occupied molecular orbital energy level of the host material.

2. The organic light-emitting device according to claim 1, characterized in that: The absolute value of the highest occupied molecular orbital energy level of the co-dopant is between the absolute value of the highest occupied molecular orbital energy level of the guest material and the absolute value of the highest occupied molecular orbital energy level of the host material; And the absolute value of the highest occupied molecular orbital energy level of the guest material is greater than the absolute value of the highest occupied molecular orbital energy level of the electron blocking layer.

3. The organic light-emitting device according to claim 1, characterized in that: The absolute value of the lowest unoccupied molecular orbital energy level of the co-dopant is smaller than the absolute value of the lowest unoccupied molecular orbital energy level of the host material, and smaller than the absolute value of the lowest unoccupied molecular orbital energy level of the guest material.

4. The organic light emitting device according to claim 3, characterized in that: The absolute value of the lowest unoccupied molecular orbital energy level of the host material, the guest material and the co-dopant is greater than the absolute value of the lowest unoccupied molecular orbital energy level of the electron blocking layer; and the absolute value of the highest occupied molecular orbital energy level of the host material, the guest material and the co-dopant is less than the absolute value of the highest occupied molecular orbital energy level of the hole blocking layer.

5. The organic light-emitting device according to claim 1, characterized in that: An absolute value of the triplet energy level of the co-dopant is greater than an absolute value of the triplet energy level of the host material.

6. The organic light-emitting device according to any one of claims 1 to 5, characterized in that: The doping ratio of the co-dopant is 0.4wt%-1wt%.

7. The organic light emitting device according to claim 6, characterized in that: The doping ratio of the guest material is 5wt%-12wt%.

8. The organic light emitting device according to claim 6, characterized in that: The co-dopant and the guest material are uniformly distributed in the light-emitting layer.

9. The organic light emitting device according to claim 1, characterized in that: The organic light emitting device further comprises: A hole transport layer, disposed on a side of the electron blocking layer away from the light-emitting layer; A hole injection layer is disposed on a side of the hole transport layer away from the light-emitting layer; An electron transport layer is disposed on the side of the hole blocking layer away from the light-emitting layer; The electron injection layer is disposed on a side of the electron transport layer away from the light emitting layer.

10. A display panel, characterized in that: The display panel comprises the organic light emitting device according to any one of claims 1 to 9.

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