WO2022056792A1

WO2022056792A1 - Organic light-emitting diode and method for manufacturing organic light-emitting diode, display device, and lighting device

Info

Publication number: WO2022056792A1
Application number: PCT/CN2020/115986
Authority: WO
Inventors: 焦志强; 黄清雨; 张娟
Original assignee: 京东方科技集团股份有限公司
Priority date: 2020-09-17
Filing date: 2020-09-17
Publication date: 2022-03-24
Also published as: CN114730847A

Abstract

An organic light-emitting diode and a method for manufacturing the organic light-emitting diode, a display device, and a lighting device. The organic light-emitting diode comprises a substrate (100), an anode (200), a light-emitting layer (600), and a cathode (1000) which are sequentially disposed; the cathode (1000) is made of a transparent conductive oxide material; the organic light-emitting diode further comprises a buffer unit (1100); the buffer unit (1100) is disposed between the light-emitting layer (600) and the cathode (1000); the buffer unit (1100) contains a first energy level transition material; the buffer unit (1100) comprises at least one of a charge injection layer, a charge separation unit, and an inorganic protective layer.

Description

有机发光二极管和制备有机发光二极管的方法、显示装置及照明装置Organic light emitting diode and method for preparing organic light emitting diode, display device and lighting device

技术领域technical field

本申请属于电致发光技术领域，具体涉及有机发光二极管和制备有机发光二极管的方法、显示装置及照明装置。The present application belongs to the technical field of electroluminescence, and in particular relates to organic light-emitting diodes and methods for preparing organic light-emitting diodes, display devices and lighting devices.

背景技术Background technique

OLED(Organic Light Emitting Diode，有机发光二极管)由于具有自发光、无需背光模组、对比度以及清晰度高、视角宽、全固化、适用于挠曲性面板、温度特性好、低功耗、响应速度快以及制造成本低等一系列优异特性，已经成为新一代平面显示装置的重点发展方向之一，因此受到越来越多的关注。为了提高有机发光二极管阴极的透过率，一部分产品会选择使用高透过率的TCO(透明导电氧化物)，比如ITO、IZO等材料。但该类型的材料用于阴极存在功函数较高、溅射工艺会损伤阴极下方的发光层材料等问题。OLED (Organic Light Emitting Diode, Organic Light Emitting Diode) has self-illumination, no backlight module, high contrast and definition, wide viewing angle, full curing, suitable for flexible panels, good temperature characteristics, low power consumption, and response speed. A series of excellent characteristics, such as high speed and low manufacturing cost, have become one of the key development directions of the new generation of flat panel display devices, so they have received more and more attention. In order to improve the transmittance of organic light-emitting diode cathodes, some products will choose to use high transmittance TCO (transparent conductive oxide), such as ITO, IZO and other materials. However, when this type of material is used in the cathode, there are problems such as high work function, and the sputtering process will damage the material of the light-emitting layer under the cathode.

由此，目前的有机发光二极管和制备有机发光二极管的方法、显示装置及照明装置仍有待改进。Therefore, the current organic light emitting diodes and methods for preparing organic light emitting diodes, display devices and lighting devices still need to be improved.

发明内容SUMMARY OF THE INVENTION

本申请是基于发明人对于以下事实和问题的发现和认识作出的：This application is made based on the inventor's discovery and knowledge of the following facts and problems:

如前所述，采用透明导电氧化物为阴极的有机发光二极管具有器件功函数较高、发光层材料易损伤的问题。以顶发射发光方案为例，选择使用高透过率的TCO(透明导电氧化物)功函数较高，约在5.0eV左右，更适合做阳极。TCO用于阴极会导致器件存在电荷注入困难的问题，且TCO制备工艺通常为磁控溅射工艺，此工艺对其下方的有机薄膜(发光层等)会有损伤，导致器件存在电压高、漏电大、寿命短等问题。虽然该问题可以通过在TCO材料与发光层之间加入HATCN(Dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile，2,3,6,7,10,11-六氰基-1,4,5,8,9,12-六氮杂苯并菲)材料得到一定程度的缓解，但是仍存在器件漏电大、不能完全解决TCO制程的损伤等问题，增大HATCN材料的厚度可以在一定程度上缓解TCO制程损伤的问题，但增大HATCN材料的厚度将导致该层载流子迁移率降低，器件电压升高。在HATCN和IZO之间增加一层CuPC材料虽然可以改善不同的层叠结构之间的能级问题，使得电荷更容易注入与传输，但也不能完全解决制程的损伤问题，且CuPC等材料对腔体的污染较严重，器件寿命无法确保。As mentioned above, the organic light emitting diode using the transparent conductive oxide as the cathode has the problems of high device work function and easy damage to the material of the light emitting layer. Taking the top emission luminescence scheme as an example, the high transmittance TCO (transparent conductive oxide) has a higher work function, about 5.0eV, which is more suitable for anode. The use of TCO for the cathode will lead to the problem of difficult charge injection in the device, and the TCO preparation process is usually a magnetron sputtering process, which will damage the organic thin film (light-emitting layer, etc.) below it, resulting in high voltage and leakage of the device. large and short lifespan. Although this problem can be solved by adding HATCN (Dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile,2, 3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene) material has been alleviated to a certain extent, but there is still a large leakage of the device, which cannot be completely solved. TCO process damage and other problems, increasing the thickness of the HATCN material can alleviate the problem of TCO process damage to a certain extent, but increasing the thickness of the HATCN material will reduce the carrier mobility of this layer and increase the device voltage. Although adding a layer of CuPC material between HATCN and IZO can improve the energy level problem between different stacked structures and make charge injection and transport easier, it cannot completely solve the problem of damage in the process, and materials such as CuPC have a negative impact on the cavity. The pollution is serious, and the life of the device cannot be guaranteed.

本申请旨在至少一定程度上缓解甚至解决上述技术问题的至少之一。The present application aims to alleviate or even solve at least one of the above technical problems at least to a certain extent.

有鉴于此，本申请提出了一种有机发光二极管，所述有机发光二极管包括依次设置的基板、阳极、发光层和阴极；所述阴极由透明导电氧化物材料制成；所述有机发光二极管还包括缓冲单元；所述缓冲单元设置在所述发光层与所述阴极之间，缓冲单元中含有第一能级过渡材料，所述缓冲单元包括电荷注入层、电荷分离单元以及无机保护层的至少之一。由此，所述缓冲单元可以对发光层与阴极之间的能级进行过渡，降低电荷注入的难度，还可以在以磁控溅射工艺制备阴极时，使位于阴极下方的有机薄膜免受损伤。In view of this, the present application proposes an organic light emitting diode, the organic light emitting diode comprises a substrate, an anode, a light emitting layer and a cathode arranged in sequence; the cathode is made of a transparent conductive oxide material; the organic light emitting diode also It includes a buffer unit; the buffer unit is arranged between the light-emitting layer and the cathode, the buffer unit contains a first energy level transition material, and the buffer unit includes at least a charge injection layer, a charge separation unit and an inorganic protective layer. one. In this way, the buffer unit can transition the energy level between the light-emitting layer and the cathode, reduce the difficulty of charge injection, and can also protect the organic thin film under the cathode from damage when the cathode is prepared by the magnetron sputtering process. .

根据本申请的示例，所述第一能级过渡材料的LUMO(Lowest Unoccupied Molecular Orbital，最低未占轨道)能级在4.5eV～8eV之间。由此，可改善采用TCO材料为阴极导致的器件电子注入困难的问题。According to an example of the present application, the LUMO (Lowest Unoccupied Molecular Orbital, lowest unoccupied orbital) energy level of the first energy level transition material is between 4.5 eV and 8 eV. Therefore, the problem of difficulty in electron injection into the device caused by using TCO material as the cathode can be improved.

根据本申请的示例，所述第一能级过渡材料包括LG101(购自LG化学(LG chem))、HATCN、F4-TCNQ(2,3,5,6-四氟-7,7’,8,8’-四氰二甲基对苯醌)的至少一种。由此，可进一步提高器件电子注入的性能。According to an example of the present application, the first energy level transition material includes LG101 (purchased from LG Chem (LG chem)), HATCN, F4-TCNQ (2,3,5,6-tetrafluoro-7,7',8 , at least one of 8'-tetracyanodimethyl-p-benzoquinone). Thereby, the performance of electron injection of the device can be further improved.

根据本申请的示例，所述电荷注入层材料包括Li、Mg、Yb的至少一种。由此，电荷注入层的材料是可以导电的，在电场中，电荷注入层材料的电子可以轻易移动，进而可以提高电子注入的效果，改善电荷注入困难的问题。According to an example of the present application, the charge injection layer material includes at least one of Li, Mg, and Yb. Therefore, the material of the charge injection layer can conduct electricity, and in an electric field, the electrons of the material of the charge injection layer can easily move, thereby improving the effect of electron injection and improving the difficulty of charge injection.

根据本申请的示例，所述无机保护层材料为MoO ₃、ZnO、ZnS中的至少之一。无机保护层可以缓解或改善TCO制程损伤的问题。 According to an example of the present application, the inorganic protective layer material is at least one of MoO ₃ , ZnO, and ZnS. Inorganic protective layers can alleviate or improve the problem of TCO process damage.

根据本申请的示例，所述电荷分离单元具有多个亚层结构，且所述电荷分离单元含有所述第一能级过渡材料。电荷分离单元可以使空穴与电子分离，改善电子注入困难的问题。并且电荷分离单元多个亚层的结构可以使电荷分离单元具有较大的厚度，还可以改善TCO制程损伤的问题。According to an example of the present application, the charge separation unit has a plurality of sublayer structures, and the charge separation unit contains the first energy level transition material. The charge separation unit can separate holes from electrons and improve the difficulty of electron injection. Moreover, the structure of the multiple sub-layers of the charge separation unit can make the charge separation unit have a larger thickness, and can also improve the problem of damage in the TCO process.

根据本申请的示例，所述电荷注入层的厚度为0.5-1.5nm。由此，可进一步提高器件的电子注入能力。According to an example of the present application, the thickness of the charge injection layer is 0.5-1.5 nm. Thereby, the electron injection capability of the device can be further improved.

根据本申请的示例，无机保护层的厚度为5-15nm。由此，可更好地在形成阴极时对有机层(如发光层等)进行保护，防止制程损伤。According to the examples of the present application, the thickness of the inorganic protective layer is 5-15 nm. Therefore, the organic layer (eg, the light-emitting layer, etc.) can be better protected when the cathode is formed to prevent process damage.

根据本申请的示例，所述电荷分离单元进一步包括第二能级过渡材料，所述第二能级过渡材料的HOMO(Highest Occupied Molecular Orbital，最高已占轨道)能级范围在4.5～8eV，且所述第一能级过渡材料的LUMO能级与第二能级过渡材料的HOMO能级的差的绝对值＜1eV。由此，可进一步提高该有机发光二极管的器件性能。According to an example of the present application, the charge separation unit further includes a second energy level transition material, and the HOMO (Highest Occupied Molecular Orbital, highest occupied orbital) energy level of the second energy level transition material ranges from 4.5 to 8 eV, and The absolute value of the difference between the LUMO energy level of the first energy level transition material and the HOMO energy level of the second energy level transition material is <1 eV. Thus, the device performance of the organic light emitting diode can be further improved.

根据本申请的示例，所述第二能级过渡材料为NPB。由此，可进一步提高该有机发光二极管的器件性能。According to an example of the present application, the second energy level transition material is NPB. Thus, the device performance of the organic light emitting diode can be further improved.

根据本申请的示例，所述电荷分离单元的厚度为25-40nm。由此，可更好地保护有机层(如发光层等)结构，防止在形成阴极时对有机层造成损伤。According to an example of the present application, the thickness of the charge separation unit is 25-40 nm. In this way, the structure of the organic layer (eg, the light-emitting layer, etc.) can be better protected to prevent damage to the organic layer when the cathode is formed.

根据本申请的示例，所述缓冲单元包括依次层叠的能级过渡层以及所述无机保护层，所述能级过渡层含有所述第一能级过渡材料；所述能级过渡层设置在远离所述阴极的一侧。根据本申请的示例，能级过渡层的厚度不小于10nm。由此，可进一步提高该有机发光二极管的器件性能。According to an example of the present application, the buffer unit includes an energy level transition layer and the inorganic protective layer stacked in sequence, the energy level transition layer contains the first energy level transition material; the energy level transition layer is disposed far away from side of the cathode. According to the example of the present application, the thickness of the energy level transition layer is not less than 10 nm. Thus, the device performance of the organic light emitting diode can be further improved.

根据本申请的示例，所述缓冲单元包括依次层叠的电荷注入层以及所述能级过渡层，所述能级过渡层含有所述第一能级过渡材料；所述电荷注入层设置在远离所述阴极的一侧。根据本申请的示例，所述能级过渡层的厚度不小于10nm；优选为10-20nm。由此，可进一步提高该有机发光二极管的器件性能。According to an example of the present application, the buffer unit includes a sequentially stacked charge injection layer and the energy level transition layer, the energy level transition layer containing the first energy level transition material; the charge injection layer is disposed away from the the side of the cathode. According to an example of the present application, the thickness of the energy level transition layer is not less than 10 nm; preferably, it is 10-20 nm. Thus, the device performance of the organic light emitting diode can be further improved.

根据本申请的示例，所述缓冲单元包括电荷分离单元和无机保护层，所述电荷分离单元设置在远离所述阴极的一侧；所述电荷分离单元包括依次层叠的第一亚层和第二亚层，所述第一亚层设置在远离所述阴极的一侧；所述第一亚层含有所述第一能级过渡材料，所述第二亚层含有所述第二能级过渡材料。根据本申请的示例，第一亚层的厚度不小于10nm；第二亚层的厚度不小于10nm，优选为10-15nm。由此，可进一步提高该有机发光二极管的器件性能。According to an example of the present application, the buffer unit includes a charge separation unit and an inorganic protective layer, the charge separation unit is disposed on a side away from the cathode; the charge separation unit includes a first sublayer and a second sublayer stacked in sequence a sublayer, the first sublayer is disposed on the side away from the cathode; the first sublayer contains the first energy level transition material, and the second sublayer contains the second energy level transition material . According to an example of the present application, the thickness of the first sublayer is not less than 10 nm; the thickness of the second sublayer is not less than 10 nm, preferably 10-15 nm. Thus, the device performance of the organic light emitting diode can be further improved.

根据本申请的示例，所述缓冲单元包括电荷分离单元，所述电荷分离单元包括依次层叠的第一亚层、第二亚层和第三亚层，所述第一亚层设置在远离所述阴极的一侧；所述第一亚层和所述第三亚层均含有所述第一能级过渡材料，所述第二亚层含有所述第二能级过渡材料。根据本申请的示例，第一亚层的厚度不小于10nm，第二亚层的厚度不小于10nm，第三亚层的厚度不小于10nm。由此，可进一步提高该有机发光二极管的器件性能。According to an example of the present application, the buffer unit includes a charge separation unit including a first sublayer, a second sublayer, and a third sublayer stacked in sequence, and the first sublayer is disposed away from the cathode The first sublayer and the third sublayer both contain the first energy level transition material, and the second sublayer contains the second energy level transition material. According to an example of the present application, the thickness of the first sublayer is not less than 10 nm, the thickness of the second sublayer is not less than 10 nm, and the thickness of the third sublayer is not less than 10 nm. Thus, the device performance of the organic light emitting diode can be further improved.

根据本申请的示例，所述缓冲单元包括电荷分离单元，所述电荷分离单元包括依次层叠的第一亚层、第二亚层、第三亚层、第四亚层和第五亚层，所述第一亚层设置在远离所述阴极的一侧；所述第一亚层、第三亚层和第五亚层均含有所述第一能级过渡材料，所述第二亚层和第四亚层均含有所述第二能级过渡材料。根据本申请的示例，所述第一亚层的厚度不小于2nm，优选为2-5nm；第二亚层的厚度不小于10nm；第三亚层的厚度不小于2nm，优选为2-5nm；第四亚层的厚度不小于10nm；第五亚层的厚度不小于10nm。由此，可进一步提高该有机发光二极管的器件性能。According to an example of the present application, the buffer unit includes a charge separation unit including a first sublayer, a second sublayer, a third sublayer, a fourth sublayer, and a fifth sublayer that are sequentially stacked, the The first sublayer is arranged on the side away from the cathode; the first sublayer, the third sublayer and the fifth sublayer all contain the first energy level transition material, and the second sublayer and the fourth sublayer all contain the first energy level transition material. The layers each contain the second level transition material. According to an example of the present application, the thickness of the first sublayer is not less than 2 nm, preferably 2-5 nm; the thickness of the second sublayer is not less than 10 nm; the thickness of the third sublayer is not less than 2 nm, preferably 2-5 nm; The thickness of the fourth sublayer is not less than 10 nm; the thickness of the fifth sublayer is not less than 10 nm. Thus, the device performance of the organic light emitting diode can be further improved.

根据本申请的示例，所述缓冲单元包括电荷分离单元，所述电荷分离单元包括依次层叠的第一亚层、第二亚层、第三亚层和第四亚层，所述第一亚层设置在远离所述阴极的一侧；所述第一亚层和第四亚层均含有所述第一能级过渡材料，所述第二亚层含有P-掺杂物和第二能级过渡材料，所述第三亚层含有所述第二能级过渡材料。根据本申请的示例，所述第一亚层的厚度不小于10nm；所述第二亚层的厚度不小于2nm，优选为2-5nm；所述第三亚层的厚度不小于10nm，优选为10-15nm；所述第四亚层的厚度不小于10nm。由此，可进一步提高该有机发光二极管的器件性能。According to an example of the present application, the buffer unit includes a charge separation unit including a first sublayer, a second sublayer, a third sublayer and a fourth sublayer that are sequentially stacked, and the first sublayer is provided On the side away from the cathode; the first and fourth sublayers both contain the first level transition material, and the second sublayer contains a P-dopant and a second level transition material , the third sublayer contains the second energy level transition material. According to an example of the present application, the thickness of the first sublayer is not less than 10 nm; the thickness of the second sublayer is not less than 2 nm, preferably 2-5 nm; the thickness of the third sublayer is not less than 10 nm, preferably 10 nm -15nm; the thickness of the fourth sublayer is not less than 10nm. Thus, the device performance of the organic light emitting diode can be further improved.

根据本申请的示例，所述缓冲单元包括电荷分离单元，所述电荷分离单元包括依次层叠的第一亚层、第二亚层、第三亚层和第四亚层，所述第一亚层设置在远离所述阴极的一侧；所述第一亚层含有所述第一能级过渡材料，所述第二亚层和所述第四亚层均含有P-掺杂物和第二能级过渡材料，所述第三亚层含有所述第二能级过渡材料。根据本申请的示例，所述第一亚层的厚度不小于10nm；所述第二亚层的厚度不小于2nm，优选为2-5nm；所述第三亚层的厚度不小于10nm，优选为10-15nm；所述第四亚层的厚度不小于10nm。由此，可进一步提高该有机发光二极管的器件性能。According to an example of the present application, the buffer unit includes a charge separation unit including a first sublayer, a second sublayer, a third sublayer and a fourth sublayer that are sequentially stacked, and the first sublayer is provided On the side remote from the cathode; the first sublayer contains the first level transition material, the second sublayer and the fourth sublayer both contain a P-dopant and a second level a transition material, the third sublayer containing the second energy level transition material. According to an example of the present application, the thickness of the first sublayer is not less than 10 nm; the thickness of the second sublayer is not less than 2 nm, preferably 2-5 nm; the thickness of the third sublayer is not less than 10 nm, preferably 10 nm -15nm; the thickness of the fourth sublayer is not less than 10nm. Thus, the device performance of the organic light emitting diode can be further improved.

本申请还提供一种制备有机发光二极管的方法，所述方法包括：在基板上制备阳极；在阳极上制备发光层；在发光层上制备缓冲单元；在缓冲单元上制备阴极；所述阴极由透明导电氧化物材料制成；所述缓冲单元中含有第一能级过渡材料，且所述缓冲单元包括电荷注入层、电荷分离单元以及无机保护层的至少之一。该方法制备的有机发光二极管可具有前面描述的有机发光二极管所具有的全部特征以及优点，在此不再赘述。总的来说，该方法可简便地获得上述有机发光二极管，且制备阴极时对有机层损伤小，器件电压低，性能较好。The present application also provides a method for preparing an organic light emitting diode, the method comprising: preparing an anode on a substrate; preparing a light-emitting layer on the anode; preparing a buffer unit on the light-emitting layer; preparing a cathode on the buffer unit; The buffer unit contains a first energy level transition material, and the buffer unit includes at least one of a charge injection layer, a charge separation unit and an inorganic protective layer. The organic light emitting diode prepared by this method can have all the features and advantages of the organic light emitting diode described above, which will not be repeated here. In general, the method can easily obtain the above-mentioned organic light-emitting diode, and the organic layer is less damaged when the cathode is prepared, the device voltage is low, and the performance is good.

本申请还提供一种显示装置，包括上述有机发光二极管。由此，该显示装置具有前面描述的有机发光二极管所具有的全部特征以及优点，在此不再赘述。总的来说，该显示装置具有器件电压低、性能较好等优点。The present application also provides a display device including the above organic light emitting diode. Therefore, the display device has all the features and advantages of the organic light emitting diode described above, which will not be repeated here. In general, the display device has the advantages of low device voltage and better performance.

本申请还提供一种照明装置，包括上述有机发光二极管。由此，该照明装置具有前面描述的有机发光二极管所具有的全部特征以及优点，在此不再赘述。总的来说，该照明装置具有器件电压低、性能较好等优点。The present application also provides a lighting device including the above organic light emitting diode. Therefore, the lighting device has all the features and advantages of the organic light emitting diodes described above, which will not be repeated here. In general, the lighting device has the advantages of low device voltage and better performance.

附图说明Description of drawings

图1是现有技术中有机发光二极管的结构示意图；1 is a schematic structural diagram of an organic light-emitting diode in the prior art;

图2为图1所示有机发光二极管的能级匹配示意图；FIG. 2 is a schematic diagram of energy level matching of the organic light emitting diode shown in FIG. 1;

图3是本申请一个实施例中有机发光二极管的结构示意图；3 is a schematic structural diagram of an organic light emitting diode in an embodiment of the present application;

图4是本申请另一个实施例中有机发光二极管的结构示意图；4 is a schematic structural diagram of an organic light emitting diode in another embodiment of the present application;

图5是本申请实施例1中有机发光二极管的能级匹配示意图；5 is a schematic diagram of energy level matching of an organic light emitting diode in Example 1 of the present application;

图6是本申请实施例2中有机发光二极管的能级匹配示意图；6 is a schematic diagram of energy level matching of organic light emitting diodes in Example 2 of the present application;

图7是本申请实施例3中有机发光二极管的能级匹配示意图；7 is a schematic diagram of energy level matching of organic light emitting diodes in Example 3 of the present application;

图8是本申请实施例4中有机发光二极管的能级匹配示意图；8 is a schematic diagram of energy level matching of an organic light emitting diode in Example 4 of the present application;

图9是本申请实施例5中有机发光二极管的能级匹配示意图；9 is a schematic diagram of energy level matching of an organic light emitting diode in Example 5 of the present application;

图10是本申请实施例6中有机发光二极管的能级匹配示意图；FIG. 10 is a schematic diagram of energy level matching of organic light emitting diodes in Example 6 of the present application;

图11是本申请实施例7中有机发光二极管的能级匹配示意图；11 is a schematic diagram of energy level matching of organic light emitting diodes in Example 7 of the present application;

附图说明Description of drawings

100-基板，200-阳极，300-空穴注入层，400-空穴传输层，500-电子阻挡层，600-发光层，700-电子传输层，800-电子注入层，900-HATCN层，1000-阴极，1100-缓冲单元。100-substrate, 200-anode, 300-hole injection layer, 400-hole transport layer, 500-electron blocking layer, 600-light emitting layer, 700-electron transport layer, 800-electron injection layer, 900-HATCN layer, 1000 - cathode, 1100 - buffer unit.

具体实施方式detailed description

下面详细描述本申请的实施例。下面描述的实施例是示例性的，仅用于解释本申请，而不能理解为对本申请的限制。实施例中未注明具体技术或条件的，按照本领域内的文献所描述的技术或条件或者按照产品说明书进行。所用试剂未注明生产厂商者，均为可以通过市购获得的常规产品。Embodiments of the present application are described in detail below. The embodiments described below are exemplary, only used to explain the present application, and should not be construed as a limitation to the present application. If no specific technique or condition is indicated in the examples, the technique or condition described in the literature in the field or the product specification is used. The reagents used are not marked with the manufacturer, they are all conventional products that can be obtained from the market.

在本申请的一个方面，本申请提供一种有机发光二极管，如图3所示，有机发光二极管包括依次设置的基板100、阳极200、发光层600和阴极1000。阴极200由透明导电氧化物材料制成。有机发光二极管还包括缓冲单元1100。缓冲单元1100设置在发光层600与阴极1000之间，缓冲单元1100含有第一能级过渡材料，缓冲单元1100包括电荷注入层、电荷分离单元以及无机保护层的至少之一。也就是说，第一能级过渡材料可位于电荷注入层、电荷分离单元以及无机保护层中的任意位置处。或者，第一能级过渡材料还可单独形成一层结构，此时缓冲单元仍旧包括电荷注入层、电荷分离单元以及无机保护层的至少之一。进一步地，第一能级过渡材料可位于电荷分离单元中的任意位置处。或者，第一能级过渡材料还可单独形成一层结构，此时缓冲单元仍旧包括电荷注入层以及无机保护层的至少之一。缓冲单元1100可以降低电荷注入的难度，还可以改善TCO制程损伤的问题。In one aspect of the present application, the present application provides an organic light emitting diode. As shown in FIG. 3 , the organic light emitting diode includes a substrate 100 , an anode 200 , a light-emitting layer 600 and a cathode 1000 arranged in sequence. The cathode 200 is made of transparent conductive oxide material. The organic light emitting diode further includes a buffer unit 1100 . The buffer unit 1100 is disposed between the light-emitting layer 600 and the cathode 1000 , the buffer unit 1100 contains a first energy level transition material, and the buffer unit 1100 includes at least one of a charge injection layer, a charge separation unit and an inorganic protective layer. That is, the first energy level transition material may be located at any position in the charge injection layer, the charge separation unit, and the inorganic protective layer. Alternatively, the first energy level transition material can also form a single-layer structure, and at this time, the buffer unit still includes at least one of a charge injection layer, a charge separation unit and an inorganic protective layer. Further, the first level transition material may be located anywhere in the charge separation unit. Alternatively, the first energy level transition material can also form a single-layer structure, and in this case, the buffer unit still includes at least one of a charge injection layer and an inorganic protective layer. The buffer unit 1100 can reduce the difficulty of charge injection, and can also improve the problem of TCO process damage.

下面为了方便理解，首先对该有机发光二极管可实现上述有益效果的原理进行简单说明：如前所述，采用TCO材料为阴极时将导致器件各层之间能级匹配程度降低，器件电压高等缺陷，且TCO材料的溅射工艺会损伤发光层等有机层。而如果在阴极和发光层之间设置包括但不限于HATCN材料进行缓冲，还是无法有效阻挡溅射工艺对发光层的损伤，出于保证器件性能的考虑，HATCN材料不可过厚，例如不能超过10nm。然而当HATCN材料厚度不足10nm时，无法有效阻挡溅射制程对有机层的损伤。本申请提出的有机发光二极管在发光层和阴极之间设置有缓冲单元，且该缓冲单元具有第一能级缓冲材料，并具有电荷注入层、无机保护层和电荷分离单元的至少之一。由此，该缓冲单元一方面可通过第一能级缓冲材料缓解TCO阴极导致的器件电压高的缺陷，另一方面可通过电荷注入层、无机保护层和电荷分离单元的至少之一对发光层等有机层进行保护，由此可更加灵活的调整缓冲单元中第一能级缓冲材料的厚度，进而可以在不影响器件性能的同时，对有机层进行有效保护，防止阴极溅射制程带来的损伤。In the following, for the convenience of understanding, the principle that the organic light emitting diode can achieve the above beneficial effects is briefly explained: as mentioned above, when the TCO material is used as the cathode, the energy level matching between the layers of the device will be reduced, and the defects of high device voltage will be caused. , and the sputtering process of the TCO material will damage the organic layers such as the light-emitting layer. However, if a buffer including but not limited to HATCN material is provided between the cathode and the light-emitting layer, the damage to the light-emitting layer by the sputtering process cannot be effectively blocked. In order to ensure the performance of the device, the HATCN material should not be too thick, such as no more than 10nm. . However, when the thickness of the HATCN material is less than 10 nm, the damage to the organic layer by the sputtering process cannot be effectively blocked. The organic light emitting diode proposed in the present application is provided with a buffer unit between the light emitting layer and the cathode, and the buffer unit has a first energy level buffer material and at least one of a charge injection layer, an inorganic protective layer and a charge separation unit. Therefore, on the one hand, the buffer unit can alleviate the defect of high device voltage caused by the TCO cathode through the first energy level buffer material; The thickness of the first energy level buffer material in the buffer unit can be adjusted more flexibly, and the organic layer can be effectively protected without affecting the performance of the device to prevent the cathode sputtering process. damage.

根据本申请的示例，第一能级过渡材料可以具有较低的LUMO能级。由此，可提升发光层和阴极之间的电子传输能力。具体地，第一能级过渡材料的LUMO能级可以在4.5eV～8eV之间。由此，可改善采用TCO材料为阴极时由于TCO材料功函数较高而导致的器件电压高等问题。According to examples of the present application, the first energy level transition material may have a lower LUMO energy level. Thereby, the electron transport ability between the light-emitting layer and the cathode can be improved. Specifically, the LUMO energy level of the first energy level transition material may be between 4.5eV˜8eV. Therefore, the problem of high device voltage caused by the higher work function of the TCO material when the TCO material is used as the cathode can be improved.

根据本申请的示例，第一能级过渡材料可以包括LG101、HATCN、F4-TCNQ的至少一种。例如可以为HATCN。由此，可以进一步改善电子注入困难的问题。According to an example of the present application, the first energy level transition material may include at least one of LG101, HATCN, and F4-TCNQ. For example, it can be HATCN. Thereby, the problem of difficulty in electron injection can be further improved.

根据本申请的一些示例，缓冲单元中可以含有能级过渡层。该能级过渡层可以是由第一能级过渡材料形成的。该能级过渡层的厚度可以为10nm或10nm以上。缓冲单元还可进一步具有无机保护层或者电荷注入层。由此，可利用无机保护层辅助能级过渡层对有机层进行保护，防止阴极制程损伤，同时还无需增大能级过渡层的厚度，从而可以保证器件性能。或者，能级过渡层的厚度也可以为10nm以上，例如可为20nm，进而可利用能级过渡层对有机层进行充分保护，并采用电荷注入层缓解能级过渡层厚度较大带来的载流子迁移率低的问题。According to some examples of the present application, the buffer unit may contain an energy level transition layer. The level transition layer may be formed of a first level transition material. The thickness of the energy level transition layer may be 10 nm or more. The buffer unit may further have an inorganic protective layer or a charge injection layer. Therefore, the organic layer can be protected by the inorganic protective layer as an auxiliary energy level transition layer to prevent damage in the cathode process, and at the same time, the thickness of the energy level transition layer does not need to be increased, so that the device performance can be guaranteed. Alternatively, the thickness of the energy level transition layer can also be more than 10 nm, for example, 20 nm, and then the organic layer can be fully protected by the energy level transition layer, and the charge injection layer can be used to alleviate the load caused by the large thickness of the energy level transition layer. The problem of low carrier mobility.

根据本申请的示例，电荷注入层材料包括Li、Mg、Yb的至少一种。电荷注入层可以位于发光层和能级过渡层之间，电荷注入层的材料是可以导电的，在电场中，电荷注入层材料的电子可以轻易移动，进而可以提高电子注入的效果，改善电荷注入困难的问题。此时即便能级过渡层的厚度较厚，该有机发光二极管的器件性能也可得到改善。电荷注入层的厚度不受特别限制，例如可以为0.5-1.5nm，如0.5nm、0.6nm、0.7nm、0.8nm、0.9nm、1nm、1.1nm、1.2nm、1.3nm、1.4nm、1.5nm。由此，可以进一步提高电子注入的效果。According to an example of the present application, the charge injection layer material includes at least one of Li, Mg, and Yb. The charge injection layer can be located between the light-emitting layer and the energy level transition layer. The material of the charge injection layer can conduct electricity. In the electric field, the electrons of the charge injection layer material can easily move, which can improve the effect of electron injection and improve the charge injection. difficult question. At this time, even if the thickness of the energy level transition layer is thicker, the device performance of the organic light emitting diode can be improved. The thickness of the charge injection layer is not particularly limited, for example, it may be 0.5-1.5 nm, such as 0.5 nm, 0.6 nm, 0.7 nm, 0.8 nm, 0.9 nm, 1 nm, 1.1 nm, 1.2 nm, 1.3 nm, 1.4 nm, 1.5 nm . Thereby, the effect of electron injection can be further enhanced.

或者，根据本申请的另一些示例，能级过渡层的厚度可以较薄，例如可以为10nm。此时可以通过在能级过渡层和阴极之间设置无机保护层来提升对有机层的保护。具体地，无机保护层材料为MoO ₃、ZnO、ZnS中的至少之一。具体地，无机保护层材料可以包含MoO ₃、 ZnO、ZnS中的一种、两种或三种。无机保护层可以改善TCO制程损伤的问题。无机保护层的厚度为5-15nm，例如5nm、6nm、7nm、8nm、9nm、10nm、11nm、12nm、13nm、14nm、15nm，由此，可以更充分的对有机层进行保护。 Alternatively, according to other examples of the present application, the thickness of the energy level transition layer may be thinner, for example, may be 10 nm. At this time, the protection of the organic layer can be improved by disposing an inorganic protective layer between the energy level transition layer and the cathode. Specifically, the inorganic protective layer material is at least one of MoO ₃ , ZnO, and ZnS. Specifically, the inorganic protective layer material may include one, two or three of MoO ₃ , ZnO, and ZnS. Inorganic protective layer can improve the problem of TCO process damage. The thickness of the inorganic protective layer is 5-15 nm, such as 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, so that the organic layer can be more fully protected.

根据本申请的另一些示例，也可将第一能级过渡材料设置在电荷分离单元中。电荷分离单元可以具有多个亚层结构，可以使空穴与电子分离，在电场中，空穴向阴极传输，可以改善电子注入困难的问题。并且电荷分离单元多个亚层的结构设计可以使电荷分离单元具有较大的厚度，可以进一步改善TCO制程损伤的问题。由此，电荷分离单元的设置可以使有机发光二极管具有较低器件电压的同时，还可以对阴极下方的有机层(如发光层等)进行防护，改善TCO制程损伤的问题。According to other examples of the present application, the first energy level transition material may also be provided in the charge separation unit. The charge separation unit can have multiple sub-layer structures, which can separate holes and electrons. In an electric field, holes are transported to the cathode, which can improve the difficulty of electron injection. In addition, the structural design of the multiple sublayers of the charge separation unit can make the charge separation unit have a larger thickness, which can further improve the problem of damage in the TCO process. Therefore, the arrangement of the charge separation unit can make the organic light emitting diode have a lower device voltage, and can also protect the organic layer (such as the light emitting layer, etc.) under the cathode, and improve the problem of damage in the TCO process.

根据本申请的示例，电荷分离单元可以进一步包括第二能级过渡材料，第二能级过渡材料的HOMO能级范围在4.5～8eV，且第一能级过渡材料的LUMO能级与第二能级过渡材料的HOMO能级的差的绝对值＜1eV。具体地，第一能级过渡材料的LUMO能级可以大于第二能级过渡材料的HOMO能级，第一能级过渡材料的LUMO能级也可以小于第二能级过渡材料的HOMO能级，只要满足两者能级差的绝对值小于＜1eV即可。由此，第二能级过渡材料可搭配第一能级过渡材料实现电子与空穴的分离。根据本申请的具体示例，第二能级过渡材料可以为NPB。由此，可进一步提高有机发光二极管的器件性能。According to an example of the present application, the charge separation unit may further include a second energy level transition material, the HOMO energy level of the second energy level transition material ranges from 4.5 to 8 eV, and the LUMO energy level of the first energy level transition material is the same as the second energy level. The absolute value of the difference in the HOMO energy level of the transition material is <1 eV. Specifically, the LUMO energy level of the first energy level transition material may be greater than the HOMO energy level of the second energy level transition material, and the LUMO energy level of the first energy level transition material may also be smaller than the HOMO energy level of the second energy level transition material, As long as the absolute value of the difference between the two energy levels is less than <1 eV. Thus, the second energy level transition material can be used with the first energy level transition material to achieve separation of electrons and holes. According to a specific example of the present application, the second energy level transition material may be NPB. Thus, the device performance of the organic light emitting diode can be further improved.

根据本申请的示例，电荷分离单元的厚度为25-40nm，例如25nm、40nm。如前所述，由于电荷分离单元中不仅含有第一能级过渡材料，还含有第二能级过渡材料，第一能级过渡材料与第二能级过渡材料的配合可以使电子空穴分离，改善电子注入困难的问题，因此电荷分离单元的厚度较大也不会严重影响器件的电压。并且，厚度较大(如大于10nm)的电荷分离单元也可起到充分保护有机层的作用，从而缓解阴极制程损伤的问题。According to an example of the present application, the thickness of the charge separation unit is 25-40 nm, eg, 25 nm, 40 nm. As mentioned above, since the charge separation unit contains not only the first energy level transition material, but also the second energy level transition material, the coordination of the first energy level transition material and the second energy level transition material can separate electron holes, The problem of difficulty in electron injection is improved, so the larger thickness of the charge separation unit will not seriously affect the voltage of the device. In addition, the charge separation unit with a large thickness (eg, greater than 10 nm) can also fully protect the organic layer, thereby alleviating the problem of damage in the cathode process.

根据本申请的一个具体示例，缓冲单元包括依次层叠的能级过渡层以及无机保护层，能级过渡层含有第一能级过渡材料。能级过渡层设置在远离阴极的一侧。根据本申请的示例，能级过渡层的厚度不小于10nm，例如10nm。由此，可以进一步提高器件的性能。需要说明的是，此处的缓冲单元还可以含有申请文件中没有述及的层状结构，本申请对没有述及的层状结构所在的位置不作限制，其可以根据使用需求进行选择，例如没有述及的层状结构可以位于能级过渡层与无机保护层之间。According to a specific example of the present application, the buffer unit includes an energy level transition layer and an inorganic protective layer stacked in sequence, and the energy level transition layer contains a first energy level transition material. The energy level transition layer is arranged on the side away from the cathode. According to an example of the present application, the thickness of the energy level transition layer is not less than 10 nm, for example, 10 nm. Thereby, the performance of the device can be further improved. It should be noted that the buffer unit here may also contain a layered structure that is not mentioned in the application documents. The application does not limit the location of the layered structure that is not mentioned. It can be selected according to the use requirements. For example, no The mentioned layered structure may be located between the energy level transition layer and the inorganic protective layer.

根据本申请的示例，缓冲单元包括依次层叠的电荷注入层以及能级过渡层，能级过渡层含有第一能级过渡材料。此时电荷注入层设置在远离阴极的一侧。根据本申请的示例，能级过渡层的厚度不小于10nm，优选为10-20nm，例如20nm。例如具体地，参考图11，可采用HATCN为能级过渡层，且能级过渡层的厚度可以较厚。以采用IZO为阴极为例， IZO的功函数为5.0eV左右，HATCN的LUMO能级为5.7eV，可提高阴极的电子注入能力。且可利用Li形成1nm厚的电荷注入层，改善由于能级过渡层厚度较厚导致的器件性能降低的问题。需要说明的是，此处的缓冲单元还可以含有申请文件中没有述及的层状结构，本申请对没有述及的层状结构所在的位置不作限制，其可以根据使用需求进行选择，例如没有述及的层状结构可以位于电荷注入层与能级过渡层之间。According to an example of the present application, the buffer unit includes a sequentially stacked charge injection layer and an energy level transition layer, and the energy level transition layer contains a first energy level transition material. At this time, the charge injection layer is disposed on the side away from the cathode. According to the example of the present application, the thickness of the energy level transition layer is not less than 10 nm, preferably 10-20 nm, eg, 20 nm. For example, referring to FIG. 11 , HATCN may be used as the energy level transition layer, and the thickness of the energy level transition layer may be relatively thick. Taking IZO as the cathode as an example, the work function of IZO is about 5.0 eV, and the LUMO energy level of HATCN is 5.7 eV, which can improve the electron injection capability of the cathode. In addition, Li can be used to form a 1 nm-thick charge injection layer, which improves the problem of device performance degradation caused by the thicker energy level transition layer. It should be noted that the buffer unit here may also contain a layered structure that is not mentioned in the application documents. The application does not limit the location of the layered structure that is not mentioned. It can be selected according to the use requirements. For example, no The mentioned layered structure may be located between the charge injection layer and the energy level transition layer.

根据本申请的示例，缓冲单元包括依次层叠的电荷分离单元和无机保护层，电荷分离单元设置在远离阴极的一侧，此时电荷分离单元可以包括依次设置的第一亚层和第二亚层，第一亚层设置在远离阴极的一侧。第一亚层含有第一能级过渡材料，第二亚层含有第二能级过渡材料。例如，第一亚层可由HATCN形成，第二亚层可由NPB形成。根据本申请的示例，第一亚层的厚度不小于10nm，例如10nm。第二亚层的厚度不小于10nm，优选为10-15nm，例如15nm。无机保护层可以为MoO ₃。参考图5，由HATCN和NPB形成的电荷分离单元可有效分离电子和空穴，且当电荷分离单元仅含有上述第一亚层和第二亚层时，NPB与MoO ₃之间的能极差更小，可令NPB靠近无机保护层一侧设置。需要说明的是，此处的缓冲单元还可以含有申请文件中没有述及的层状结构，本申请对没有述及的层状结构所在的位置不作限制，其可以根据使用需求进行选择，例如没有述及的层状结构可以位于电荷分离单元和无机保护层之间。 According to an example of the present application, the buffer unit includes a charge separation unit and an inorganic protective layer stacked in sequence, the charge separation unit is disposed on a side away from the cathode, and in this case, the charge separation unit may include a first sublayer and a second sublayer disposed in sequence , the first sublayer is disposed on the side away from the cathode. The first sublayer contains the first energy level transition material, and the second sublayer contains the second energy level transition material. For example, the first sublayer may be formed of HATCN, and the second sublayer may be formed of NPB. According to an example of the present application, the thickness of the first sublayer is not less than 10 nm, eg, 10 nm. The thickness of the second sublayer is not less than 10 nm, preferably 10-15 nm, such as 15 nm. The inorganic protective layer may be MoO ₃ . Referring to Figure 5, the charge separation unit formed by HATCN and NPB can effectively separate electrons and holes, and when the charge separation unit contains only the above _- mentioned first and second sublayers, the energy difference between NPB and MoO3 Smaller, the NPB can be placed close to the side of the inorganic protective layer. It should be noted that the buffer unit here may also contain layered structures that are not mentioned in the application documents. This application does not limit the location of the layered structures that are not mentioned. The mentioned layered structure may be located between the charge separation unit and the inorganic protective layer.

根据本申请的示例，缓冲单元可以仅包括电荷分离单元，此时电荷分离单元包括依次层叠的第一亚层、第二亚层和第三亚层，第一亚层设置在远离阴极的一侧。第一亚层和第三亚层均含有第一能级过渡材料，第二亚层含有第二能级过渡材料。根据本申请的示例，第一亚层的厚度不小于10nm，例如10nm。第二亚层的厚度不小于10nm，优选为10-20nm，例如20nm。第三亚层的厚度不小于10nm，例如10nm。具体地，参考图7，由于采用含有三个亚层的结构设计使电荷分离单元整体的厚度较大，例如可以为40nm，此时无需设置无机保护层即可利用电荷分离单元对有机层进行充分保护，防止阴极制程损伤。需要说明的是，此处的缓冲单元还可以含有申请文件中没有述及的层状结构，本申请对没有述及的层状结构所在的位置不作限制，其可以根据使用需求进行选择，例如没有述及的层状结构可以位于第一亚层、第二亚层、第三亚层的任意两个亚层之间。According to an example of the present application, the buffer unit may only include a charge separation unit, in which case the charge separation unit includes a first sublayer, a second sublayer and a third sublayer stacked in sequence, and the first sublayer is disposed on a side away from the cathode. Both the first sublayer and the third sublayer contain the first energy level transition material, and the second sublayer contains the second energy level transition material. According to an example of the present application, the thickness of the first sublayer is not less than 10 nm, eg, 10 nm. The thickness of the second sublayer is not less than 10 nm, preferably 10-20 nm, such as 20 nm. The thickness of the third sublayer is not less than 10 nm, eg, 10 nm. Specifically, referring to FIG. 7 , the overall thickness of the charge separation unit is relatively large due to the structure design with three sublayers, for example, it can be 40 nm. At this time, the charge separation unit can be used to fully conduct the organic layer separation without setting an inorganic protective layer. protection to prevent damage to the cathode process. It should be noted that the buffer unit here may also contain a layered structure that is not mentioned in the application documents. The application does not limit the location of the layered structure that is not mentioned. It can be selected according to the use requirements. For example, no The mentioned layered structure may be located between any two sublayers of the first sublayer, the second sublayer, and the third sublayer.

根据本申请的示例，缓冲单元可以仅包括电荷分离单元，此时电荷分离单元包括依次层叠的第一亚层、第二亚层、第三亚层、第四亚层和第五亚层，第一亚层设置在远离阴极的一侧。第一亚层、第三亚层和第五亚层均含有第一能级过渡材料，第二亚层和第四亚层均含有第二能级过渡材料。根据本申请的示例，第一亚层的厚度不小于2nm，优选为2-5nm，例如5nm。第二亚层的厚度不小于10nm，例如10nm。第三亚层的厚度不小于2nm，优选为2-5nm，例如5nm。第四亚层的厚度不小于10nm，例如10nm。第五亚层的厚度不小于10nm，例如10nm。具体地，参考图8，由于采用含有五个亚层的结构设计使电荷分离单元整体的厚度较大，例如可以为40nm，此时无需设置无机保护层即可利用电荷分离单元对有机层进行充分保护，防止阴极制程损伤。需要说明的是，此处的缓冲单元还可以含有申请文件中没有述及的层状结构，本申请对没有述及的层状结构所在的位置不作限制，其可以根据使用需求进行选择，例如没有述及的层状结构可以位于第一亚层、第二亚层、第三亚层、第四亚层、第五亚层的任意两个亚层之间。According to an example of the present application, the buffer unit may only include a charge separation unit, and in this case, the charge separation unit includes a first sublayer, a second sublayer, a third sublayer, a fourth sublayer, and a fifth sublayer, which are sequentially stacked. The sublayer is arranged on the side remote from the cathode. The first sublayer, the third sublayer and the fifth sublayer all contain the first energy level transition material, and the second sublayer and the fourth sublayer each contain the second energy level transition material. According to the example of the present application, the thickness of the first sublayer is not less than 2 nm, preferably 2-5 nm, eg, 5 nm. The thickness of the second sublayer is not less than 10 nm, eg, 10 nm. The thickness of the third sublayer is not less than 2 nm, preferably 2-5 nm, such as 5 nm. The thickness of the fourth sublayer is not less than 10 nm, eg, 10 nm. The thickness of the fifth sublayer is not less than 10 nm, eg, 10 nm. Specifically, referring to FIG. 8 , the overall thickness of the charge separation unit is relatively large due to the structure design with five sub-layers, for example, it can be 40 nm. At this time, the charge separation unit can be used to fully conduct the organic layer without setting an inorganic protective layer. protection to prevent damage to the cathode process. It should be noted that the buffer unit here may also contain a layered structure that is not mentioned in the application documents. The application does not limit the location of the layered structure that is not mentioned. It can be selected according to the use requirements. For example, no The mentioned layered structure may be located between any two sublayers of the first sublayer, the second sublayer, the third sublayer, the fourth sublayer, and the fifth sublayer.

根据本申请的示例，缓冲单元可以仅包括电荷分离单元，此时电荷分离单元包括依次层叠的第一亚层、第二亚层、第三亚层和第四亚层，第一亚层设置在远离阴极的一侧。第一亚层和第四亚层均含有第一能级过渡材料，第二亚层含有P-掺杂物和第二能级过渡材料，第三亚层含有第二能级过渡材料。P-掺杂物包括第一能级过渡材料、NDP-9的至少一种。根据本申请的示例，第一亚层的厚度不小于10nm，例如10nm。第二亚层的厚度不小于2nm，优选为2-5nm，例如5nm。第三亚层的厚度不小于10nm，优选为10-15nm，例如15nm。第四亚层的厚度不小于10nm，例如10nm。具体地，参考图9，由于采用含有四个亚层的结构设计使电荷分离单元的整体厚度较大，例如可以为40nm，此时无需设置无机保护层即可利用电荷分离单元对阴极下方的有机层进行充分保护，防止阴极制程损伤。需要说明的是，此处的缓冲单元还可以含有申请文件中没有述及的层状结构，本申请对没有述及的层状结构所在的位置不作限制，其可以根据使用需求进行选择，例如没有述及的层状结构可以位于第一亚层、第二亚层、第三亚层、第四亚层的任意两个亚层之间。According to an example of the present application, the buffer unit may only include a charge separation unit, and in this case, the charge separation unit includes a first sublayer, a second sublayer, a third sublayer and a fourth sublayer that are stacked in sequence, and the first sublayer is disposed far away from side of the cathode. The first sublayer and the fourth sublayer each contain the first level transition material, the second sublayer contains the P-dopant and the second level transition material, and the third sublayer contains the second level transition material. The P-dopant includes at least one of the first level transition material, NDP-9. According to an example of the present application, the thickness of the first sublayer is not less than 10 nm, eg, 10 nm. The thickness of the second sublayer is not less than 2 nm, preferably 2-5 nm, eg 5 nm. The thickness of the third sublayer is not less than 10 nm, preferably 10-15 nm, such as 15 nm. The thickness of the fourth sublayer is not less than 10 nm, eg, 10 nm. Specifically, referring to FIG. 9 , the overall thickness of the charge separation unit is relatively large due to the structure design with four sub-layers, for example, it can be 40 nm. At this time, the charge separation unit can be used to remove the organic layer under the cathode without setting an inorganic protective layer. The layer is fully protected to prevent damage to the cathode process. It should be noted that the buffer unit here may also contain a layered structure that is not mentioned in the application documents. The application does not limit the location of the layered structure that is not mentioned. It can be selected according to the use requirements. For example, no The mentioned layered structure may be located between any two sublayers of the first sublayer, the second sublayer, the third sublayer, and the fourth sublayer.

根据本申请的示例，缓冲单元可以仅包括电荷分离单元，此时电荷分离单元包括依次层叠的第一亚层、第二亚层、第三亚层和第四亚层，第一亚层设置在远离阴极的一侧。第一亚层含有第一能级过渡材料，第二亚层和第四亚层均含有P-掺杂物和第二能级过渡材料，第三亚层含有第二能级过渡材料。P-掺杂物包括第一能级过渡材料、NDP-9的至少一种。根据本申请的示例，第一亚层的厚度不小于10nm，例如10nm。第二亚层的厚度不小于2nm，优选为2-5nm，例如5nm。第三亚层的厚度不小于10nm，优选为10-15nm，例如15nm。第四亚层的厚度不小于10nm，例如10nm。需要说明的是，此处的缓冲单元还可以含有申请文件中没有述及的层状结构，本申请对没有述及的层状结构所在的位置不作限制，其可以根据使用需求进行选择，例如没有述及的层状结构可以位于第一亚层、第二亚层、第三亚层、第四亚层的任意两个亚层之间。According to an example of the present application, the buffer unit may only include a charge separation unit, and in this case, the charge separation unit includes a first sublayer, a second sublayer, a third sublayer and a fourth sublayer that are stacked in sequence, and the first sublayer is disposed far away from side of the cathode. The first sublayer contains the first level transition material, the second and fourth sublayers both contain P-dopants and the second level transition material, and the third sublayer contains the second level transition material. The P-dopant includes at least one of the first level transition material, NDP-9. According to an example of the present application, the thickness of the first sublayer is not less than 10 nm, eg, 10 nm. The thickness of the second sublayer is not less than 2 nm, preferably 2-5 nm, eg 5 nm. The thickness of the third sublayer is not less than 10 nm, preferably 10-15 nm, such as 15 nm. The thickness of the fourth sublayer is not less than 10 nm, eg, 10 nm. It should be noted that the buffer unit here may also contain a layered structure that is not mentioned in the application documents. The application does not limit the location of the layered structure that is not mentioned. It can be selected according to the use requirements. For example, no The mentioned layered structure may be located between any two sublayers of the first sublayer, the second sublayer, the third sublayer, and the fourth sublayer.

根据本申请的一些示例，参考图4，该有机发光二极管还可进一步具有以下结构的至少之一：空穴注入层300、空穴传输层400、电子阻挡层500、电子传输层(Electron Transport Layer，ETL)700、电子注入层800。阳极200与发光层600之间依次设置有空穴注入层300、空穴传输层400和电子阻挡层500，空穴注入层300设置在靠近阳极200的一侧。发光层600与缓冲单元1100之间依次设置有电子传输层700和电子注入层800，电子传输层700设置在靠近发光层600的一侧。本申请对阳极、空穴注入层、空穴传输层、电子阻挡层、发光层、电子传输层、电子注入层的材料不作限制。例如，阳极可以为银薄膜和氧化铟锡薄膜，空穴注入层材料可以为HATCN，空穴传输层材料可以为NPB(N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)-benzidine)，电子阻挡层材料可以为DBTPB(N4,N4'-bis(dibenzo[b,d]thiophen-4-yl)-N4,N4'-diphenylbiphenyl-4,4'-diaMine)或Ir(ppz) ₃(Tris(phenylpyrazole)iridium)的任意一种，发光层材料可以为MADN:DSA-Ph，发光层材料的掺杂主体为MADN(2-methyl-9,10-bis(naphthalen-2-yl)anthracene)，发光层材料的掺杂客体为DSA-Ph(1-4-di-[4-(N,N-diphenyl)amino]styryl-benzene)，电子传输层材料可以为Bphen(4,7-diphenyl-1,10-phenanthroline)，电子注入层材料可以为ETL:LiQ，例如Bphen:LiQ。 According to some examples of the present application, referring to FIG. 4 , the organic light emitting diode may further have at least one of the following structures: a hole injection layer 300 , a hole transport layer 400 , an electron blocking layer 500 , an electron transport layer (Electron Transport Layer) , ETL) 700 , and electron injection layer 800 . A hole injection layer 300 , a hole transport layer 400 and an electron blocking layer 500 are arranged between the anode 200 and the light emitting layer 600 in sequence, and the hole injection layer 300 is arranged on the side close to the anode 200 . An electron transport layer 700 and an electron injection layer 800 are arranged between the light emitting layer 600 and the buffer unit 1100 in sequence, and the electron transport layer 700 is arranged on the side close to the light emitting layer 600 . The present application does not limit the materials of the anode, the hole injection layer, the hole transport layer, the electron blocking layer, the light emitting layer, the electron transport layer and the electron injection layer. For example, the anode can be silver thin film and indium tin oxide thin film, the hole injection layer material can be HATCN, and the hole transport layer material can be NPB(N,N'-bis(naphthalen-1-yl)-N,N'- bis(phenyl)-benzidine), the electron blocking layer material can be DBTPB(N4,N4'-bis(dibenzo[b,d]thiophen-4-yl)-N4,N4'-diphenylbiphenyl-4,4'-diaMine) or Ir(ppz) ₃ (Tris(phenylpyrazole) iridium), the material of the light-emitting layer can be MADN:DSA-Ph, and the doping host of the material of the light-emitting layer is MADN(2-methyl-9,10-bis(naphthalen) -2-yl)anthracene), the doping guest of the light-emitting layer material is DSA-Ph(1-4-di-[4-(N,N-diphenyl)amino]styryl-benzene), and the electron transport layer material can be Bphen (4,7-diphenyl-1,10-phenanthroline), the material of the electron injection layer can be ETL:LiQ, such as Bphen:LiQ.

此处需要特别说明的是，在本申请中术语“有机层”应做广义理解。该有机层包括发光层，当该有机发光二极管还包括电子传输层、电子注入层等结构时，该有机层还可包括发光层、电子传输层和电子注入层。总的来说，术语“有机层”含有发光层以及发光层和阴极之间除去缓冲单元以外的结构。It should be noted here that the term "organic layer" in this application should be understood in a broad sense. The organic layer includes a light-emitting layer, and when the organic light-emitting diode further includes an electron transport layer, an electron injection layer, and the like, the organic layer may further include a light-emitting layer, an electron transport layer, and an electron injection layer. In general, the term "organic layer" includes the light-emitting layer and the structure between the light-emitting layer and the cathode excluding the buffer unit.

本申请还提供一种制备有机发光二极管的方法，方法包括：在基板上制备阳极。在阳极上制备发光层。在发光层上制备缓冲单元。在缓冲单元上制备阴极，阴极由透明导电氧化物材料制成。缓冲单元中含有第一能级过渡材料，且缓冲单元包括电荷注入层、电荷分离单元以及无机保护层的至少之一。The present application also provides a method for preparing an organic light emitting diode, the method comprising: preparing an anode on a substrate. A light-emitting layer is prepared on the anode. A buffer unit is prepared on the light-emitting layer. A cathode is prepared on the buffer unit, and the cathode is made of a transparent conductive oxide material. The buffer unit contains a first energy level transition material, and the buffer unit includes at least one of a charge injection layer, a charge separation unit and an inorganic protective layer.

具体地，制备有机发光二极管的方法包括以下步骤：在基板的上方依次制备得到阳极、空穴注入层、空穴传输层、电子阻挡层、发光层、电子传输层、电子注入层。在电子注入层上制备缓冲单元。在缓冲单元上制备阴极。由于该方法制备的有机发光二极管具有前述的缓冲单元，可有效防止阴极制程损伤有机层，因此无需对制备阴极的工艺进行改进。Specifically, the method for preparing an organic light emitting diode includes the following steps: sequentially preparing an anode, a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, an electron transport layer, and an electron injection layer on the substrate. A buffer unit is prepared on the electron injection layer. A cathode is prepared on the buffer unit. Since the organic light emitting diode prepared by this method has the aforementioned buffer unit, which can effectively prevent the organic layer from being damaged in the cathode manufacturing process, it is not necessary to improve the cathode manufacturing process.

本申请还提供一种显示装置，包括上述有机发光二极管。由此，该显示装置具有前面描述的有机发光二极管所具有的全部特征以及优点，在此不再赘述。The present application also provides a display device including the above organic light emitting diode. Therefore, the display device has all the features and advantages of the organic light emitting diode described above, which will not be repeated here.

本申请还提供一种照明装置，包括上述有机发光二极管。由此，该照明装置具有前面描述的有机发光二极管所具有的全部特征以及优点，在此不再赘述。The present application also provides a lighting device including the above organic light emitting diode. Therefore, the lighting device has all the features and advantages of the organic light emitting diodes described above, which will not be repeated here.

本申请下面所描述的实施例，除非另有说明，所使用的试剂均可以从市场上购得或者可以通过本申请所描述的方法制备而得。In the examples described below in this application, unless otherwise stated, the reagents used can be purchased from the market or can be prepared by the methods described in this application.

对比例1Comparative Example 1

有机发光二极管包括依次设置的基板、阳极、空穴注入层、空穴传输层、电子阻挡层、发光层、电子传输层、电子注入层、阴极。The organic light emitting diode includes a substrate, an anode, a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, an electron transport layer, an electron injection layer, and a cathode arranged in sequence.

其中，基板为玻璃，阳极是银薄膜和氧化铟锡(ITO)薄膜，空穴注入层材料为HATCN，厚度为10nm。空穴传输层材料为NPB，厚度为150nm。电子阻挡层材料为DBTPB，厚度为4nm。发光层材料为MADN:DSA-Ph，厚度为20nm，DSA-Ph占发光层材料的质量比为5％。电子传输层材料为Bphen，厚度为35nm。电子注入层材料为Bphen:LiQ，厚度为80nm。阴极材料为IZO，厚度为200nm。The substrate is glass, the anode is silver thin film and indium tin oxide (ITO) thin film, the hole injection layer material is HATCN, and the thickness is 10 nm. The hole transport layer material is NPB with a thickness of 150 nm. The electron blocking layer material is DBTPB with a thickness of 4 nm. The material of the light-emitting layer is MADN:DSA-Ph, the thickness is 20 nm, and the mass ratio of DSA-Ph to the material of the light-emitting layer is 5%. The electron transport layer material is Bphen, and the thickness is 35 nm. The material of the electron injection layer is Bphen:LiQ, and the thickness is 80 nm. The cathode material is IZO with a thickness of 200 nm.

各功能层的顺序依次为：HATCN(10nm)/NPB(150nm)/DBTPB(4nm)/MADN:DSA-Ph(20nm，5％)/Bphen(35nm)/Bphen:LiQ(80nm)/IZO(200nm)。The order of each functional layer is: HATCN(10nm)/NPB(150nm)/DBTPB(4nm)/MADN:DSA-Ph(20nm, 5%)/Bphen(35nm)/Bphen:LiQ(80nm)/IZO(200nm) ).

对比例2Comparative Example 2

有机发光二极管包括依次设置的基板、阳极、空穴注入层、空穴传输层、电子阻挡层、发光层、电子传输层、电子注入层、HATCN层、阴极。The organic light emitting diode includes a substrate, an anode, a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, an electron transport layer, an electron injection layer, a HATCN layer, and a cathode arranged in sequence.

采用玻璃为基板，阳极是银薄膜和氧化铟锡(ITO)薄膜，空穴注入层材料为HATCN，厚度为10nm。空穴传输层材料为NPB，厚度为150nm。电子阻挡层材料为DBTPB，厚度为4nm。发光层材料为MADN:DSA-Ph，厚度为20nm，DSA-Ph占发光层材料的质量比为5％。电子传输层材料为Bphen，厚度为35nm。电子注入层材料为Bphen:LiQ，厚度为70nm。HATCN层的厚度为10nm。阴极材料为IZO，厚度为200nm。有机发光二极管具有如图1所示的结构。Glass is used as the substrate, the anode is made of silver thin film and indium tin oxide (ITO) thin film, and the material of the hole injection layer is HATCN with a thickness of 10 nm. The hole transport layer material is NPB with a thickness of 150 nm. The electron blocking layer material is DBTPB with a thickness of 4 nm. The material of the light-emitting layer is MADN:DSA-Ph, the thickness is 20 nm, and the mass ratio of DSA-Ph to the material of the light-emitting layer is 5%. The electron transport layer material is Bphen, and the thickness is 35 nm. The material of the electron injection layer is Bphen:LiQ, and the thickness is 70 nm. The thickness of the HATCN layer is 10 nm. The cathode material is IZO with a thickness of 200 nm. The organic light emitting diode has a structure as shown in FIG. 1 .

各功能层的顺序依次为：HATCN(10nm)/NPB(150nm)/DBTPB(4nm)/MADN:DSA-Ph(20nm，5％)/Bphen(35nm)/Bphen:LiQ(70nm)/HATCN(10nm)/IZO(200nm)。上述有机发光二极管的能级匹配示意图如图2所示，阴极的电子经HATCN传输到电子注入层，能级差大，存在电荷注入困难的问题，器件电压高。并且还存在TCO制程损伤的问题。The order of each functional layer is: HATCN(10nm)/NPB(150nm)/DBTPB(4nm)/MADN:DSA-Ph(20nm, 5%)/Bphen(35nm)/Bphen:LiQ(70nm)/HATCN(10nm )/IZO (200 nm). The energy level matching schematic diagram of the above organic light emitting diode is shown in Figure 2. The electrons from the cathode are transferred to the electron injection layer through the HATCN, the energy level difference is large, and there is the problem of difficulty in charge injection, and the device voltage is high. And there is also the problem of TCO process damage.

实施例1Example 1

有机发光二极管包括依次设置的基板、阳极、空穴注入层、空穴传输层、电子阻挡层、发光层、电子传输层、电子注入层、缓冲单元、阴极。The organic light emitting diode includes a substrate, an anode, a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, an electron transport layer, an electron injection layer, a buffer unit, and a cathode arranged in sequence.

其中，基板为玻璃，阳极是银薄膜和氧化铟锡(ITO)薄膜，空穴注入层材料为HATCN，厚度为10nm。空穴传输层材料为NPB，厚度为150nm。电子阻挡层材料为DBTPB，厚度为4nm。发光层材料为MADN:DSA-Ph，厚度为20nm，发光层中的掺杂主体为MADN，掺杂客体为DSA-Ph，DSA-Ph占发光层材料的质量比为5％。电子传输层材料为Bphen，厚度为35nm。电子注入层材料为Bphen:LiQ，厚度为55nm。The substrate is glass, the anode is silver thin film and indium tin oxide (ITO) thin film, the hole injection layer material is HATCN, and the thickness is 10 nm. The hole transport layer material is NPB with a thickness of 150 nm. The electron blocking layer material is DBTPB with a thickness of 4 nm. The material of the light-emitting layer is MADN:DSA-Ph, the thickness is 20 nm, the doping host in the light-emitting layer is MADN, the doping guest is DSA-Ph, and the mass ratio of DSA-Ph to the material of the light-emitting layer is 5%. The electron transport layer material is Bphen, and the thickness is 35 nm. The material of the electron injection layer is Bphen:LiQ, and the thickness is 55 nm.

本实施例的缓冲单元包括依次设置的电荷分离单元和无机保护层，电荷分离单元设置在远离阴极的一侧。电荷分离单元包括两个亚层，具体地，电荷分离单元包括依次设置的第一亚层和第二亚层，第一亚层设置在远离阴极的一侧。第一亚层含有第一能级过渡材料，第一能级过渡材料为HATCN，第一亚层的厚度为10nm。第二亚层含有第二能级过渡材料，第二能级过渡材料为NPB，第二亚层的厚度为15nm。无机保护层为MoO ₃，厚度为10nm。 The buffer unit of this embodiment includes a charge separation unit and an inorganic protective layer arranged in sequence, and the charge separation unit is arranged on a side away from the cathode. The charge separation unit includes two sublayers. Specifically, the charge separation unit includes a first sublayer and a second sublayer that are arranged in sequence, and the first sublayer is arranged on a side away from the cathode. The first sublayer contains a first energy level transition material, the first energy level transition material is HATCN, and the thickness of the first sublayer is 10 nm. The second sublayer contains a second energy level transition material, the second energy level transition material is NPB, and the thickness of the second sublayer is 15 nm. The inorganic protective layer is MoO ₃ with a thickness of 10 nm.

阴极材料为IZO，厚度为200nm。The cathode material is IZO with a thickness of 200 nm.

各功能层的顺序依次为：HATCN(10nm)/NPB(150nm)/DBTPB(4nm)/MADN:DSA-Ph(20nm，5％)/Bphen(35nm)/Bphen:LiQ(55nm)/HATCN(10nm)/NPB(15nm)/MoO ₃(10nm)/IZO(200nm)。 The order of each functional layer is: HATCN(10nm)/NPB(150nm)/DBTPB(4nm)/MADN:DSA-Ph(20nm, 5%)/Bphen(35nm)/Bphen:LiQ(55nm)/HATCN(10nm )/NPB(15nm)/MoO3 ₍ 10nm)/IZO(200nm).

制备有机发光二极管的方法为：在基板的上方依次制备得到阳极、空穴注入层、空穴传输层、电子阻挡层、发光层、电子传输层、电子注入层。在电子注入层上制备缓冲单元。在缓冲单元上制备阴极。The method for preparing the organic light emitting diode is as follows: an anode, a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, an electron transport layer and an electron injection layer are sequentially prepared on the substrate. A buffer unit is prepared on the electron injection layer. A cathode is prepared on the buffer unit.

具体地，制备有机发光二极管的方法包括：将带有Ag/ITO(其面电阻<30Ω/□)的透明玻璃基板依次在去离子水、丙酮和无水乙醇中超声环境中清洗，结束后用N ₂吹干并进行O ₂等离子体的处理。最后将处理好的基板置于蒸镀腔室中，待真空度低于5×10 ^-4Pa后，通过真空热蒸镀的方式，在ITO表面依次沉积各功能层。 Specifically, the method for preparing an organic light emitting diode includes: cleaning a transparent glass substrate with Ag/ITO (the surface resistance of which is <30Ω/□) in an ultrasonic environment in deionized water, acetone and absolute ethanol in sequence, and then using N ₂ blow dry and treat with O ₂ plasma. Finally, the processed substrate is placed in an evaporation chamber, and after the vacuum degree is lower than 5×10 ^-4 Pa, various functional layers are sequentially deposited on the surface of ITO by vacuum thermal evaporation.

实施例1中有机发光二极管的能级匹配示意图如图5所示，本实施例的缓冲单元可以使空穴与电子分离，在电场的作用下，空穴传输到阴极，可以改善电子注入困难的问题，器件电压低。并且本实施例使用了无机材料MoO ₃，可以改善TCO制程损伤的问题。 The schematic diagram of energy level matching of the organic light emitting diode in Example 1 is shown in Figure 5. The buffer unit in this example can separate holes and electrons. Under the action of an electric field, holes are transported to the cathode, which can improve the difficulty of electron injection. Problem, device voltage is low. In addition, this embodiment uses the inorganic material MoO ₃ , which can improve the problem of damage in the TCO process.

实施例2Example 2

本实施例的基板与实施例1相同，本实施例的阳极、空穴注入层、空穴传输层、电子阻挡层、发光层和阴极的材料及各层的厚度均与实施例1相同。本实施例的电子传输层材料为Bphen，厚度为35nm。电子注入层材料为Bphen:LiQ，厚度为60nm。The substrate of this embodiment is the same as that of Embodiment 1, and the materials and thicknesses of the anode, hole injection layer, hole transport layer, electron blocking layer, light-emitting layer and cathode of this embodiment are the same as those of Embodiment 1. The material of the electron transport layer in this embodiment is Bphen, and the thickness is 35 nm. The material of the electron injection layer is Bphen:LiQ, and the thickness is 60 nm.

本实施例的缓冲单元包括依次设置的能级过渡层和无机保护层，能级过渡层设置在远离阴极的一侧。能级过渡层含有第一能级过渡材料，第一能级过渡材料为HATCN，能级过渡层的厚度为10nm。无机保护层材料为MoO ₃，厚度为10nm。 The buffer unit of this embodiment includes an energy level transition layer and an inorganic protective layer arranged in sequence, and the energy level transition layer is arranged on the side away from the cathode. The energy level transition layer contains a first energy level transition material, the first energy level transition material is HATCN, and the thickness of the energy level transition layer is 10 nm. The inorganic protective layer material is MoO ₃ with a thickness of 10 nm.

各功能层的顺序依次为：HATCN(10nm)/NPB(150nm)/DBTPB(4nm)/MADN:DSA-Ph(20nm，5％)/Bphen(35nm)/Bphen:LiQ(60nm)/HATCN(10nm)/MoO ₃(10nm)/IZO(200nm)。 The order of each functional layer is: HATCN(10nm)/NPB(150nm)/DBTPB(4nm)/MADN:DSA-Ph(20nm, 5%)/Bphen(35nm)/Bphen:LiQ(60nm)/HATCN(10nm) )/MoO ₃ (10 nm)/IZO (200 nm).

参照实施例1中制备有机发光二极管的方法，可以制备得到实施例2中有机发光二极管。Referring to the method for preparing an organic light emitting diode in Example 1, the organic light emitting diode in Example 2 can be prepared.

实施例2中有机发光二极管的能级匹配示意图如图6所示，本实施例使用了无机材料MoO ₃，可以改善TCO制程损伤的问题，并且本实施例的器件电压低。 The schematic diagram of energy level matching of the organic light emitting diode in Example 2 is shown in FIG. 6 . In this example, the inorganic material MoO ₃ is used, which can improve the problem of damage in the TCO process, and the device voltage of this example is low.

实施例3Example 3

本实施例的基板与实施例1相同，本实施例的阳极、空穴注入层、空穴传输层、电子阻挡层、发光层、电子传输层和阴极的材料及各层的厚度与实施例1相同。本实施例的电子注入层材料为Bphen:LiQ，厚度为60nm。The substrate of this example is the same as that of Example 1, and the materials and thicknesses of the anode, hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, electron transport layer and cathode of this example are the same as those of Example 1. same. The material of the electron injection layer in this embodiment is Bphen:LiQ, and the thickness is 60 nm.

本实施例的缓冲单元包括电荷分离单元，电荷分离单元包括三个亚层，具体地，电荷分离单元包括依次设置的第一亚层、第二亚层和第三亚层，第一亚层设置在远离阴极的一侧。第一亚层和第三亚层均含有第一能级过渡材料，第一能级过渡材料为HATCN，即第一亚层和第三亚层均含有HATCN。第二亚层含有第二能级过渡材料，第二能级过渡材料为NPB，即第二亚层含有NPB。第一亚层的厚度为10nm，第二亚层的厚度为20nm，第三亚层的厚度为10nm。The buffer unit in this embodiment includes a charge separation unit, and the charge separation unit includes three sublayers. Specifically, the charge separation unit includes a first sublayer, a second sublayer, and a third sublayer arranged in sequence, and the first sublayer is arranged at The side away from the cathode. Both the first sublayer and the third sublayer contain a first energy level transition material, and the first energy level transition material is HATCN, that is, both the first sublayer and the third sublayer contain HATCN. The second sublayer contains the second energy level transition material, and the second energy level transition material is NPB, that is, the second sublayer contains NPB. The thickness of the first sublayer is 10 nm, the thickness of the second sublayer is 20 nm, and the thickness of the third sublayer is 10 nm.

各功能层的顺序依次为：HATCN(10nm)/NPB(150nm)/DBTPB(4nm)/MADN:DSA-Ph(20nm，5％)/Bphen(35nm)/Bphen:LiQ(60nm)/HATCN(10nm)/NPB(20nm)/HATCN(10nm)/IZO(200nm)。The order of each functional layer is: HATCN(10nm)/NPB(150nm)/DBTPB(4nm)/MADN:DSA-Ph(20nm, 5%)/Bphen(35nm)/Bphen:LiQ(60nm)/HATCN(10nm )/NPB(20nm)/HATCN(10nm)/IZO(200nm).

参照实施例1中制备有机发光二极管的方法，可以制备得到实施例3中有机发光二极管。Referring to the method for preparing an organic light emitting diode in Example 1, the organic light emitting diode in Example 3 can be prepared.

实施例3中有机发光二极管的能级匹配示意图如图7所示，本实施例的缓冲单元可以使空穴与电子分离，在电场的作用下，空穴传输到阴极，可以改善电子注入困难的问题，器件电压低。并且本实施例中多个亚层的结构设计可以改善TCO制程损伤的问题。The schematic diagram of the energy level matching of the organic light emitting diode in Example 3 is shown in Figure 7. The buffer unit in this example can separate holes and electrons. Under the action of an electric field, holes are transported to the cathode, which can improve the difficulty of electron injection. Problem, device voltage is low. In addition, the structural design of multiple sub-layers in this embodiment can improve the problem of damage in the TCO process.

实施例4Example 4

本实施例的基板与实施例1相同，本实施例的阳极、空穴注入层、空穴传输层、电子阻挡层、发光层、电子传输层和阴极的材料及各层的厚度均与实施例1相同。本实施例的电子注入层材料为Bphen:LiQ，厚度为60nm。The substrate of this embodiment is the same as that of Embodiment 1, and the materials and thicknesses of the anode, hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, electron transport layer and cathode of this embodiment are the same as those of the embodiment. 1 is the same. The material of the electron injection layer in this embodiment is Bphen:LiQ, and the thickness is 60 nm.

本实施例的缓冲单元包括电荷分离单元。电荷分离单元包括五个亚层，电荷分离单元的厚度为40nm。具体地，电荷分离单元包括依次设置的第一亚层、第二亚层、第三亚层、第四亚层和第五亚层，第一亚层设置在远离阴极的一侧。第一亚层、第三亚层和第五亚层均含有第一能级过渡材料，第一能级过渡材料为HATCN，即第一亚层、第三亚层和第五亚层均含有HATCN。第二亚层和第四亚层均含有第二能级过渡材料，第二能级过渡材料为NPB，即第二亚层和第四亚层均含有NPB。第一亚层的厚度为5nm，第二亚层的厚度为10nm，第三亚层的厚度为5nm，第四亚层的厚度为10nm，第五亚层的厚度为10nm。The buffer unit of this embodiment includes a charge separation unit. The charge separation unit includes five sublayers, and the thickness of the charge separation unit is 40 nm. Specifically, the charge separation unit includes a first sublayer, a second sublayer, a third sublayer, a fourth sublayer and a fifth sublayer that are arranged in sequence, and the first sublayer is arranged on a side away from the cathode. The first sublayer, the third sublayer and the fifth sublayer all contain the first energy level transition material, and the first energy level transition material is HATCN, that is, the first sublayer, the third sublayer and the fifth sublayer all contain HATCN. Both the second sublayer and the fourth sublayer contain a second energy level transition material, and the second energy level transition material is NPB, that is, both the second sublayer and the fourth sublayer contain NPB. The thickness of the first sublayer is 5 nm, the thickness of the second sublayer is 10 nm, the thickness of the third sublayer is 5 nm, the thickness of the fourth sublayer is 10 nm, and the thickness of the fifth sublayer is 10 nm.

各功能层的顺序依次为：HATCN(10nm)/NPB(150nm)/DBTPB(4nm)/MADN:DSA-Ph(20nm，5％)/Bphen(35nm)/Bphen:LiQ(60nm)/HATCN(5nm)/NPB(10nm)/HATCN(5nm)/NPB(10nm)/HATCN(10nm)/IZO(200nm)。The order of each functional layer is: HATCN(10nm)/NPB(150nm)/DBTPB(4nm)/MADN:DSA-Ph(20nm, 5%)/Bphen(35nm)/Bphen:LiQ(60nm)/HATCN(5nm) )/NPB(10nm)/HATCN(5nm)/NPB(10nm)/HATCN(10nm)/IZO(200nm).

参照实施例1中制备有机发光二极管的方法，可以制备得到实施例4中有机发光二极管。Referring to the method for preparing an organic light emitting diode in Example 1, the organic light emitting diode in Example 4 can be prepared.

实施例4中有机发光二极管的能级匹配示意图如图8所示，本实施例的缓冲单元可以使空穴与电子分离，在电场的作用下，空穴传输到阴极，可以改善电子注入困难的问题，器件电压低。并且本实施例中多个亚层的结构设计可以改善TCO制程损伤的问题。The schematic diagram of energy level matching of the organic light emitting diode in Example 4 is shown in Figure 8. The buffer unit in this example can separate holes and electrons. Under the action of an electric field, holes are transported to the cathode, which can improve the difficulty of electron injection. Problem, device voltage is low. In addition, the structural design of multiple sub-layers in this embodiment can improve the problem of damage in the TCO process.

实施例5Example 5

本实施例的缓冲单元包括依次设置的电荷分离单元。电荷分离单元包括四个亚层，具体地，电荷分离单元包括依次设置的第一亚层、第二亚层、第三亚层和第四亚层，第一亚层设置在远离阴极的一侧。第一亚层和第四亚层均含有第一能级过渡材料，第一能级过渡材料为HATCN，即第一亚层和第四亚层均含有HATCN。第二亚层含有P-掺杂物和第二能级过渡材料，具体地，P-掺杂物为HATCN，第二亚层含有HATCN和NPB，其中HATCN占第二亚层材料的质量比为5％。第三亚层含有第二能级过渡材料，第二能级过渡材料为 NPB，即第三亚层含有NPB。第一亚层的厚度为10nm，第二亚层的厚度为5nm，第三亚层的厚度为15nm，第四亚层的厚度为10nm。The buffer unit of this embodiment includes charge separation units arranged in sequence. The charge separation unit includes four sublayers, specifically, the charge separation unit includes a first sublayer, a second sublayer, a third sublayer and a fourth sublayer arranged in sequence, and the first sublayer is arranged on a side away from the cathode. Both the first sublayer and the fourth sublayer contain a first energy level transition material, and the first energy level transition material is HATCN, that is, both the first sublayer and the fourth sublayer contain HATCN. The second sublayer contains a P-dopant and a second energy level transition material, specifically, the P-dopant is HATCN, and the second sublayer contains HATCN and NPB, wherein the mass ratio of HATCN to the second sublayer material is 5%. The third sublayer contains the second energy level transition material, and the second energy level transition material is NPB, that is, the third sublayer contains NPB. The thickness of the first sublayer is 10 nm, the thickness of the second sublayer is 5 nm, the thickness of the third sublayer is 15 nm, and the thickness of the fourth sublayer is 10 nm.

各功能层的顺序依次为：HATCN(10nm)/NPB(150nm)/DBTPB(4nm)/MADN:DSA-Ph(20nm，5％)/Bphen(35nm)/Bphen:LiQ(60nm)/HATCN(10nm)/NPB:HATCN(5nm,1％)/NPB(15nm)/HATCN(10nm)/IZO(200nm)。The order of each functional layer is: HATCN(10nm)/NPB(150nm)/DBTPB(4nm)/MADN:DSA-Ph(20nm, 5%)/Bphen(35nm)/Bphen:LiQ(60nm)/HATCN(10nm )/NPB:HATCN(5nm,1%)/NPB(15nm)/HATCN(10nm)/IZO(200nm).

参照实施例1中制备有机发光二极管的方法，可以制备得到实施例5中有机发光二极管。Referring to the method for preparing an organic light emitting diode in Example 1, the organic light emitting diode in Example 5 can be prepared.

实施例5中有机发光二极管的能级匹配示意图如图9所示，本实施例的缓冲单元可以使空穴与电子分离，在电场的作用下，空穴传输到阴极，可以改善电子注入困难的问题，器件电压低。并且本实施例中多个亚层的结构设计可以改善TCO制程损伤的问题。The schematic diagram of energy level matching of the organic light emitting diode in Example 5 is shown in Figure 9. The buffer unit in this example can separate holes and electrons. Under the action of an electric field, holes are transported to the cathode, which can improve the difficulty of electron injection. Problem, device voltage is low. In addition, the structural design of multiple sub-layers in this embodiment can improve the problem of damage in the TCO process.

实施例6Example 6

有机发光二极管包括依次设置的基板、阳极、空穴注入层、空穴传输层、电子阻挡层、发光层、电子传输层、电子注入层、缓冲单元和阴极。The organic light emitting diode includes a substrate, an anode, a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, an electron transport layer, an electron injection layer, a buffer unit and a cathode arranged in sequence.

本实施例的缓冲单元包括电荷分离单元。电荷分离单元包括四个亚层，具体地，电荷分离单元包括依次设置的第一亚层、第二亚层、第三亚层和第四亚层，第一亚层设置在远离阴极的一侧。第一亚层含有第一能级过渡材料，第一能级过渡材料为HATCN，即第一亚层含有HATCN。第二亚层和第四亚层均含有P-掺杂物和第二能级过渡材料，具体地，P-掺杂物为HATCN，第二能级过渡材料为NPB，即第二亚层和第四亚层均含有HATCN和NPB，其中HATCN占第二亚层材料的质量比为5％，HATCN占第四亚层材料的质量比为5％。第三亚层含有第二能级过渡材料，第二能级过渡材料为NPB，即第三亚层含有NPB。第一亚层的厚度为10nm，第二亚层的厚度为5nm，第三亚层的厚度为15nm，第四亚层的厚度为10nm。The buffer unit of this embodiment includes a charge separation unit. The charge separation unit includes four sublayers, specifically, the charge separation unit includes a first sublayer, a second sublayer, a third sublayer and a fourth sublayer arranged in sequence, and the first sublayer is arranged on a side away from the cathode. The first sublayer contains a first energy level transition material, and the first energy level transition material is HATCN, that is, the first sublayer contains HATCN. Both the second sublayer and the fourth sublayer contain a P-dopant and a second energy level transition material, specifically, the P-dopant is HATCN, and the second energy level transition material is NPB, that is, the second sublayer and The fourth sublayer both contains HATCN and NPB, wherein the mass ratio of HATCN to the material of the second sublayer is 5%, and the mass ratio of HATCN to the material of the fourth sublayer is 5%. The third sublayer contains the second energy level transition material, and the second energy level transition material is NPB, that is, the third sublayer contains NPB. The thickness of the first sublayer is 10 nm, the thickness of the second sublayer is 5 nm, the thickness of the third sublayer is 15 nm, and the thickness of the fourth sublayer is 10 nm.

各功能层的顺序依次为：HATCN(10nm)/NPB(150nm)/DBTPB(4nm)/MADN:DSA-Ph(20nm,5％)/Bphen(35nm)/Bphen:LiQ(60nm)/HATCN(10nm)/NPB:HATCN(5nm,1％)/NPB(15nm)/NPB:HATCN(10nm)/IZO(200nm)。The order of each functional layer is: HATCN(10nm)/NPB(150nm)/DBTPB(4nm)/MADN:DSA-Ph(20nm,5%)/Bphen(35nm)/Bphen:LiQ(60nm)/HATCN(10nm) )/NPB:HATCN(5nm,1%)/NPB(15nm)/NPB:HATCN(10nm)/IZO(200nm).

参照实施例1中制备有机发光二极管的方法，可以制备得到实施例6中有机发光二极管。Referring to the method for preparing an organic light emitting diode in Example 1, the organic light emitting diode in Example 6 can be prepared.

实施例6中有机发光二极管的能级匹配示意图如图10所示，本实施例的缓冲单元可以使空穴与电子分离，在电场的作用下，空穴传输到阴极，可以改善电子注入困难的问题，器件电压低。并且本实施例中多个亚层的结构设计可以改善TCO制程损伤的问题。The schematic diagram of energy level matching of the organic light emitting diode in Example 6 is shown in Figure 10. The buffer unit in this example can separate holes and electrons. Under the action of an electric field, holes are transported to the cathode, which can improve the difficulty of electron injection. Problem, device voltage is low. In addition, the structural design of multiple sub-layers in this embodiment can improve the problem of damage in the TCO process.

实施例7Example 7

本实施例的基板与实施例1相同，本实施例的阳极、空穴注入层、空穴传输层、电子阻挡层、发光层、电子传输层和阴极的材料及各层的厚度与实施例1相同。本实施例中电子注入层材料为Bphen:LiQ，厚度为60nm。The substrate of this example is the same as that of Example 1, and the materials and thicknesses of the anode, hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, electron transport layer and cathode of this example are the same as those of Example 1. same. In this embodiment, the material of the electron injection layer is Bphen:LiQ, and the thickness is 60 nm.

本实施例的缓冲单元包括依次设置的电荷注入层以及能级过渡层，电荷注入层设置在远离阴极的一侧。电荷注入层材料包含Li，电荷注入层的厚度为1nm。能级过渡层含有第一能级过渡材料，第一能级过渡材料为HATCN，即能级过渡层含有HATCN，能级过渡层的厚度为20nm。The buffer unit of this embodiment includes a charge injection layer and an energy level transition layer arranged in sequence, and the charge injection layer is arranged on a side away from the cathode. The charge injection layer material contains Li, and the thickness of the charge injection layer is 1 nm. The energy level transition layer contains a first energy level transition material, and the first energy level transition material is HATCN, that is, the energy level transition layer contains HATCN, and the thickness of the energy level transition layer is 20 nm.

各功能层的顺序依次为：HATCN(10nm)/NPB(150nm)/DBTPB(4nm)/MADN:DSA-Ph(20nm，5％)/Bphen(35nm)/Bphen:LiQ(60nm)/Li(1nm)/HATCN(20nm)/IZO(200nm)。The order of each functional layer is: HATCN(10nm)/NPB(150nm)/DBTPB(4nm)/MADN:DSA-Ph(20nm, 5%)/Bphen(35nm)/Bphen:LiQ(60nm)/Li(1nm )/HATCN(20nm)/IZO(200nm).

参照实施例1中制备有机发光二极管的方法，可以制备得到实施例7中有机发光二极管。Referring to the method for preparing an organic light emitting diode in Example 1, the organic light emitting diode in Example 7 can be prepared.

实施例7中有机发光二极管的能级匹配示意图如图11所示，本实施例的Li层可以导电，在电场的作用下，Li层的电子可以轻易移动，可以提高电子注入的效果，可以改善电子注入困难的问题，降低器件电压。The schematic diagram of the energy level matching of the organic light emitting diode in Example 7 is shown in Figure 11. The Li layer in this example can conduct electricity. Under the action of the electric field, the electrons in the Li layer can easily move, which can improve the effect of electron injection and improve the The problem of difficult electron injection reduces the device voltage.

发明人对实施例1-7以及对比例1-2获得的有机发光二极管的性能进行测试。测试条件为：在给器件施加电流密度为10mA/cm ²时，测试器件的电压和发光效率。给器件施加-5V的电压，测试器件电流密度情况，当电流密度小于等于-1x10 ^-2mA/cm ²时，判定为漏电不良点，对总计140片样品进行测试。测试结果见下表1。 The inventors tested the properties of the organic light emitting diodes obtained in Examples 1-7 and Comparative Examples 1-2. The test conditions are: when a current density of 10 mA/cm ² is applied to the device, the voltage and luminous efficiency of the device are tested. A voltage of -5V was applied to the device, and the current density of the device was tested. When the current density was less than or equal to -1x10 ^-2 mA/cm ² , it was judged as a defective leakage point, and a total of 140 samples were tested. The test results are shown in Table 1 below.

表1各方案中有机发光二极管的器件电压、发光效率以及漏电情况对比表Table 1 Comparison table of device voltage, luminous efficiency and leakage of organic light emitting diodes in each scheme

由表1可知，实施例1-7的器件电压均低于对比例1-2中的器件电压，实施例1-7中器件的发光效率大于等于对比例1-2的发光效率，对比例1-2中存在漏电问题，实施例1-7中不存在漏电问题。相比于现有的有机发光二极管，本申请增加缓冲单元后，有机发光二极管的漏电问题得到了解决，从而证明本申请的缓冲单元对避免TCO溅射的损伤效果明显，器件的寿命长。而且本申请器件的电压降低，从而证明本申请可以改善电子注入困难的问题。It can be seen from Table 1 that the device voltages of Examples 1-7 are all lower than the device voltages in Comparative Examples 1-2, and the luminous efficiency of the devices in Examples 1-7 is greater than or equal to the luminous efficiency of Comparative Examples 1-2, and Comparative Example 1 There is a leakage problem in -2, and there is no leakage problem in Examples 1-7. Compared with the existing organic light emitting diode, after the buffer unit is added in the present application, the leakage problem of the organic light emitting diode is solved, which proves that the buffer unit of the present application has an obvious effect on avoiding TCO sputtering damage and has a long device life. Moreover, the voltage of the device of the present application is reduced, which proves that the present application can improve the problem of difficulty in electron injection.

在不相互矛盾的情况下，本领域的技术人员可以将本说明书中描述的不同示例以及不同示例的特征进行结合和组合。另外，需要说明的是，本说明书中，术语“第一”、“第二”、“第三”、“第四”、“第五”仅用于描述目的，而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量。Those skilled in the art may combine and combine the different examples described in this specification and the features of the different examples without contradicting each other. In addition, it should be noted that in this specification, the terms "first", "second", "third", "fourth" and "fifth" are only used for the purpose of description, and should not be construed as indicating or implying relative Importance or implicitly indicates the number of technical features indicated.

尽管上面已经示出和描述了本申请的实施例，可以理解的是，上述实施例是示例性的，不能理解为对本申请的限制，本领域的普通技术人员在本申请的范围内可以对上述实施例进行变化、修改、替换和变型。Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limitations to the present application. Embodiments are subject to variations, modifications, substitutions and variations.

Claims

一种有机发光二极管，所述有机发光二极管包括依次设置的基板、阳极、发光层和阴极；所述阴极由透明导电氧化物材料制成；An organic light-emitting diode, the organic light-emitting diode comprises a substrate, an anode, a light-emitting layer and a cathode arranged in sequence; the cathode is made of a transparent conductive oxide material;

所述有机发光二极管还包括缓冲单元；所述缓冲单元设置在所述发光层与所述阴极之间，所述缓冲单元含有第一能级过渡材料，所述缓冲单元包括电荷注入层、电荷分离单元以及无机保护层的至少之一。The organic light emitting diode further includes a buffer unit; the buffer unit is disposed between the light-emitting layer and the cathode, the buffer unit contains a first energy level transition material, and the buffer unit includes a charge injection layer, a charge separation layer at least one of a unit and an inorganic protective layer.
根据权利要求1所述的有机发光二极管，所述第一能级过渡材料的LUMO能级在4.5eV～8eV之间。According to the organic light emitting diode of claim 1, the LUMO energy level of the first energy level transition material is between 4.5eV˜8eV.
根据权利要求1或2所述的有机发光二极管，所述第一能级过渡材料包括LG101、HATCN、F4-TCNQ的至少一种。According to the organic light emitting diode of claim 1 or 2, the first energy level transition material comprises at least one of LG101, HATCN, and F4-TCNQ.
根据权利要求1所述的有机发光二极管，所述电荷注入层材料包括Li、Mg、Yb的至少一种；The organic light emitting diode according to claim 1, wherein the charge injection layer material comprises at least one of Li, Mg, and Yb;

所述无机保护层材料为MoO ₃、ZnO、ZnS中的至少之一； The inorganic protective layer material is at least one of MoO ₃ , ZnO, and ZnS;

所述电荷分离单元具有多个亚层结构，且所述电荷分离单元含有所述第一能级过渡材料。The charge separation unit has a plurality of sublayer structures, and the charge separation unit contains the first energy level transition material.
根据权利要求4所述的有机发光二极管，所述电荷注入层的厚度为0.5-1.5nm。According to the organic light emitting diode of claim 4, the thickness of the charge injection layer is 0.5-1.5 nm.
根据权利要求4所述的有机发光二极管，无机保护层的厚度为5-15nm。According to the organic light emitting diode of claim 4, the thickness of the inorganic protective layer is 5-15 nm.
根据权利要求4所述的有机发光二极管，所述电荷分离单元进一步包括第二能级过渡材料，所述第二能级过渡材料的HOMO能级范围在4.5～8eV，且所述第一能级过渡材料的LUMO能级与第二能级过渡材料的HOMO能级的差的绝对值＜1eV。The organic light emitting diode according to claim 4, the charge separation unit further comprises a second energy level transition material, the HOMO energy level of the second energy level transition material is in the range of 4.5˜8 eV, and the first energy level The absolute value of the difference between the LUMO energy level of the transition material and the HOMO energy level of the transition material at the second energy level is <1 eV.
根据权利要求7所述的有机发光二极管，所述第二能级过渡材料为NPB。The organic light emitting diode according to claim 7, wherein the second energy level transition material is NPB.
根据权利要求7所述的有机发光二极管，所述电荷分离单元的厚度为25-40nm。According to the organic light emitting diode of claim 7, the thickness of the charge separation unit is 25-40 nm.
根据权利要求4所述的有机发光二极管，所述缓冲单元包括依次层叠的能级过渡层以及所述无机保护层，所述能级过渡层含有所述第一能级过渡材料；所述能级过渡层设置在远离所述阴极的一侧。The organic light emitting diode according to claim 4, wherein the buffer unit comprises an energy level transition layer and the inorganic protective layer stacked in sequence, the energy level transition layer containing the first energy level transition material; the energy level transition layer The transition layer is arranged on the side away from the cathode.
根据权利要求10所述的有机发光二极管，所述能级过渡层的厚度不小于10nm。According to the organic light emitting diode of claim 10, the thickness of the energy level transition layer is not less than 10 nm.
根据权利要求1所述的有机发光二极管，所述缓冲单元包括依次层叠的电荷注入层以及所述能级过渡层，所述能级过渡层含有所述第一能级过渡材料；所述电荷注入层设置在远离所述阴极的一侧。The organic light emitting diode of claim 1, wherein the buffer unit comprises a charge injection layer and the energy level transition layer stacked in sequence, the energy level transition layer containing the first energy level transition material; the charge injection The layer is arranged on the side remote from the cathode.
根据权利要求12所述的有机发光二极管，所述能级过渡层的厚度不小于10nm。The organic light emitting diode according to claim 12, wherein the thickness of the energy level transition layer is not less than 10 nm.
根据权利要求7所述的有机发光二极管，所述缓冲单元包括电荷分离单元和无机保护层，所述电荷分离单元设置在远离所述阴极的一侧；所述电荷分离单元包括依次层叠的第一亚层和第二亚层，所述第一亚层设置在远离所述阴极的一侧；The organic light emitting diode according to claim 7, wherein the buffer unit comprises a charge separation unit and an inorganic protective layer, the charge separation unit is disposed on a side away from the cathode; the charge separation unit comprises a first a sublayer and a second sublayer, the first sublayer is disposed on a side away from the cathode;

所述第一亚层含有所述第一能级过渡材料，所述第二亚层含有所述第二能级过渡材料。The first sublayer contains the first level transition material and the second sublayer contains the second level transition material.
根据权利要求14所述的有机发光二极管，所述第一亚层的厚度不小于10nm；The organic light emitting diode according to claim 14, wherein the thickness of the first sublayer is not less than 10 nm;

所述第二亚层的厚度不小于10nm。The thickness of the second sublayer is not less than 10 nm.
根据权利要求7所述的有机发光二极管，所述缓冲单元包括包括电荷分离单元，所述电荷分离单元包括依次层叠的第一亚层、第二亚层和第三亚层，所述第一亚层设置在远离所述阴极的一侧；The organic light emitting diode of claim 7, wherein the buffer unit comprises a charge separation unit comprising a first sublayer, a second sublayer and a third sublayer stacked in sequence, the first sublayer arranged on the side away from the cathode;

所述第一亚层和所述第三亚层均含有所述第一能级过渡材料，所述第二亚层含有所述第二能级过渡材料。The first sublayer and the third sublayer each contain the first level transition material, and the second sublayer contains the second level transition material.
根据权利要求16所述的有机发光二极管，所述第一亚层的厚度不小于10nm；The organic light emitting diode according to claim 16, wherein the thickness of the first sublayer is not less than 10 nm;

所述第二亚层的厚度不小于10nm；The thickness of the second sublayer is not less than 10 nm;

所述第三亚层的厚度不小于10nm。The thickness of the third sublayer is not less than 10 nm.
根据权利要求7所述的有机发光二极管，所述缓冲单元包括电荷分离单元，所述电荷分离单元包括依次层叠的第一亚层、第二亚层、第三亚层、第四亚层和第五亚层，所述第一亚层设置在远离所述阴极的一侧；The organic light emitting diode of claim 7, wherein the buffer unit comprises a charge separation unit comprising a first sublayer, a second sublayer, a third sublayer, a fourth sublayer and a fifth sublayer stacked in sequence a sublayer, the first sublayer is arranged on a side away from the cathode;

所述第一亚层、第三亚层和第五亚层均含有所述第一能级过渡材料，所述第二亚层和第四亚层均含有所述第二能级过渡材料。The first sublayer, the third sublayer and the fifth sublayer all contain the first energy level transition material, and the second sublayer and the fourth sublayer each contain the second energy level transition material.
根据权利要求18所述的有机发光二极管，所述第一亚层的厚度不小于2nm；The organic light emitting diode according to claim 18, wherein the thickness of the first sublayer is not less than 2 nm;

所述第二亚层的厚度不小于10nm；The thickness of the second sublayer is not less than 10 nm;

所述第三亚层的厚度不小于2nm；The thickness of the third sublayer is not less than 2nm;

所述第四亚层的厚度不小于10nm；The thickness of the fourth sublayer is not less than 10 nm;

所述第五亚层的厚度不小于10nm。The thickness of the fifth sublayer is not less than 10 nm.
根据权利要求7所述的有机发光二极管，所述缓冲单元包括电荷分离单元，所述电荷分离单元包括依次层叠的第一亚层、第二亚层、第三亚层和第四亚层，所述第一亚层设置在远离所述阴极的一侧；The organic light emitting diode of claim 7, wherein the buffer unit comprises a charge separation unit comprising a first sublayer, a second sublayer, a third sublayer and a fourth sublayer stacked in sequence, the the first sublayer is disposed on the side away from the cathode;

所述第一亚层和第四亚层含有所述第一能级过渡材料，所述第二亚层含有P-掺杂物和第二能级过渡材料，所述第三亚层含有所述第二能级过渡材料。The first sublayer and the fourth sublayer contain the first level transition material, the second sublayer contains a P-dopant and a second level transition material, and the third sublayer contains the first level transition material. Two-level transition materials.
根据权利要求20所述的有机发光二极管，所述第一亚层的厚度不小于10nm；The organic light emitting diode according to claim 20, wherein the thickness of the first sublayer is not less than 10 nm;

所述第二亚层的厚度不小于2nm；The thickness of the second sublayer is not less than 2nm;

所述第三亚层的厚度不小于10nm；The thickness of the third sublayer is not less than 10 nm;

所述第四亚层的厚度不小于10nm。The thickness of the fourth sublayer is not less than 10 nm.
根据权利要求7所述的有机发光二极管，所述缓冲单元包括电荷分离单元，所述电荷分离单元包括依次层叠的第一亚层、第二亚层、第三亚层和第四亚层，所述第一亚层设置在远离所述阴极的一侧；The organic light emitting diode of claim 7, wherein the buffer unit comprises a charge separation unit comprising a first sublayer, a second sublayer, a third sublayer and a fourth sublayer stacked in sequence, the the first sublayer is disposed on the side away from the cathode;

所述第一亚层含有所述第一能级过渡材料，所述第二亚层和所述第四亚层均含有P-掺杂物和第二能级过渡材料，所述第三亚层含有所述第二能级过渡材料。The first sublayer contains the first level transition material, the second sublayer and the fourth sublayer each contain a P-dopant and a second level transition material, and the third sublayer contains the second energy level transition material.
根据权利要求22所述的有机发光二极管，所述第一亚层的厚度不小于10nm；The organic light emitting diode according to claim 22, wherein the thickness of the first sublayer is not less than 10 nm;

所述第二亚层的厚度不小于2nm；The thickness of the second sublayer is not less than 2nm;

所述第三亚层的厚度不小于10nm；The thickness of the third sublayer is not less than 10 nm;

所述第四亚层的厚度不小于10nm。The thickness of the fourth sublayer is not less than 10 nm.
根据权利要求1所述的有机发光二极管，所述有机发光二极管进一步包括空穴注入层、空穴传输层、电子阻挡层、电子传输层、电子注入层；The organic light emitting diode according to claim 1, further comprising a hole injection layer, a hole transport layer, an electron blocking layer, an electron transport layer, and an electron injection layer;

所述阳极与所述发光层之间依次设置有空穴注入层、空穴传输层和电子阻挡层，所述空穴注入层设置在靠近所述阳极的一侧；A hole injection layer, a hole transport layer and an electron blocking layer are sequentially arranged between the anode and the light-emitting layer, and the hole injection layer is arranged on the side close to the anode;

所述发光层与所述缓冲单元之间依次设置有电子传输层和电子注入层，所述电子传输层设置在靠近所述发光层的一侧。An electron transport layer and an electron injection layer are sequentially arranged between the light-emitting layer and the buffer unit, and the electron transport layer is arranged on the side close to the light-emitting layer.
一种制备有机发光二极管的方法，所述方法包括：A method of preparing an organic light emitting diode, the method comprising:

在基板上制备阳极；preparing an anode on a substrate;

在阳极上制备发光层；prepare a light-emitting layer on the anode;

在发光层上制备缓冲单元；preparing a buffer unit on the light-emitting layer;

在缓冲单元上制备阴极；所述阴极由透明导电氧化物材料制成；preparing a cathode on the buffer unit; the cathode is made of a transparent conductive oxide material;

所述缓冲单元中含有第一能级过渡材料，且所述缓冲单元包括电荷注入层、电荷分离单元以及无机保护层的至少之一。The buffer unit contains a first energy level transition material, and the buffer unit includes at least one of a charge injection layer, a charge separation unit and an inorganic protective layer.
一种显示装置，包括权利要求1-24任一项所述的有机发光二极管。A display device, comprising the organic light emitting diode according to any one of claims 1-24.
一种照明装置，包括权利要求1-24任一项所述的有机发光二极管。A lighting device, comprising the organic light emitting diode according to any one of claims 1-24.