WO2021253786A1

WO2021253786A1 - Composite material and preparation method therefor and quantum dot light-emitting diode

Info

Publication number: WO2021253786A1
Application number: PCT/CN2020/139382
Authority: WO
Inventors: 聂志文; 张旋宇; 刘文勇
Original assignee: Tcl科技集团股份有限公司
Priority date: 2020-06-15
Filing date: 2020-12-25
Publication date: 2021-12-23
Also published as: CN113801648A; CN113801648B

Abstract

Disclosed are a composite material and a preparation method therefor and a quantum dot light-emitting diode. The composite material comprises n-type metal oxide nanoparticles and organic molecules represented by formula I attached to the surface of the n-type metal oxide nanoparticles, and carboxyl groups on the organic molecules are bound to the surface of the n-type metal oxide nanoparticles; in formula I, R₁ is -(CH₂)_n-, and n is an integer greater than or equal to 1. The composite material not only effectively shortens the spacing of the metal oxide nanoparticles, but also ensures that the nanoparticles are not agglomerated; moreover, the organic molecules having bipolar groups are bound to the surface of the n-type metal oxide nanoparticles, so that the surface defects thereof can be reduced, the electron conduction capacity among the nanoparticles is enhanced, thereby improving the electron mobility of the composite material, and thus the electron transport capability of the composite material is enhanced.

Description

复合材料及其制备方法和量子点发光二极管Composite material and preparation method thereof and quantum dot light emitting diode

本申请要求于2020年06月15日提交的中国专利申请No.202010543936.4的优先权，其全部内容通过引用结合在本申请中。This application claims the priority of Chinese Patent Application No. 202010543936.4 filed on June 15, 2020, the entire content of which is incorporated into this application by reference.

技术领域Technical field

本申请涉及发光器件材料技术领域，具体涉及一种复合材料及其制备方法和量子点发光二极管。This application relates to the technical field of light-emitting device materials, in particular to a composite material and a preparation method thereof, and a quantum dot light-emitting diode.

背景技术Background technique

量子点的电致发光器件仍然存在效率低、寿命短等缺陷，而构筑高效能QLED器件常用溶液法制备，通常使用无机金属氧化物如氧化锌作为QLED的电子传输层(Electron Transport Layer，ETL)。为了保持量子点优异的光学稳定性，量子点表面配体一般呈非极性，这样导致与无机金属氧化物接触差，使得电子注入更加困难。另外，现有QLED器件一般电子迁移率远高于空穴迁移率，使得QD/ETL界面的电荷积累现象非常严重，对QLED器件的效率和寿命都产生了非常不利的影响。而且金属氧化物纳米粒子在旋涂成膜后的膜结构常表现为无序的松散结构，含有大量的各种缺陷，如微孔等。同时，在某些特定方向容易发生堆积，均匀性较差。Quantum dot electroluminescent devices still have defects such as low efficiency and short lifespan. The construction of high-performance QLED devices is usually prepared by solution method, and inorganic metal oxides such as zinc oxide are usually used as the electron transport layer (Electron Transport Layer, ETL) of QLEDs. . In order to maintain the excellent optical stability of quantum dots, the surface ligands of quantum dots are generally non-polar, which leads to poor contact with inorganic metal oxides and makes electron injection more difficult. In addition, existing QLED devices generally have electron mobility much higher than hole mobility, which makes the charge accumulation phenomenon at the QD/ETL interface very serious, which has a very negative impact on the efficiency and life of the QLED device. Moreover, the film structure of the metal oxide nanoparticles after the spin coating is formed into a film often appears as a disordered loose structure, containing a large number of various defects, such as micropores. At the same time, it is easy to accumulate in some specific directions, and the uniformity is poor.

发明内容Summary of the invention

为解决上述技术问题，本申请实施例采用的技术方案是：In order to solve the above technical problems, the technical solutions adopted in the embodiments of this application are:

第一方面，本申请提供了一种复合材料，包括n型金属氧化物纳米颗粒和连接在所述n型金属氧化物纳米颗粒表面的如下式I所示的有机分子，所述有机分子上的羧基结合在所述n型金属氧化物纳米颗粒表面；In the first aspect, the present application provides a composite material, comprising n-type metal oxide nanoparticles and organic molecules shown in the following formula I attached to the surface of the n-type metal oxide nanoparticles, on the organic molecules The carboxyl group is bound to the surface of the n-type metal oxide nanoparticles;

其中，R ₁为-(CH ₂) _n-，n为大于或等于1的整数。 Wherein, R ₁ is -(CH ₂ ) _n -, and n is an integer greater than or equal to 1.

第二方面，本申请提供了一种复合材料的制备方法，包括以下步骤：In the second aspect, this application provides a method for preparing a composite material, including the following steps:

提供n型金属氧化物纳米颗粒和如下式II所示的二羧酸单酯有机物；Provide n-type metal oxide nanoparticles and dicarboxylic acid monoester organic compounds as shown in the following formula II;

将所述n型金属氧化物纳米颗粒和二羧酸单酯有机物溶于极性溶剂中，进行加热处理，得到混合溶液；Dissolving the n-type metal oxide nanoparticles and the organic dicarboxylic acid monoester in a polar solvent, and performing heating treatment to obtain a mixed solution;

将所述混合溶液进行固液分离，得到所述复合材料；Subjecting the mixed solution to solid-liquid separation to obtain the composite material;

其中，R ₁为-(CH ₂) _n-，R ₂为-O(CH ₂) _mCH ₃，n为大于或等于1的整数，m为大于或等于0的整数。 Wherein, R ₁ is -(CH ₂ ) _n -, R ₂ is -O(CH ₂ ) _m CH ₃ , n is an integer greater than or equal to 1, and m is an integer greater than or equal to 0.

第三方面，提供一种量子点发光二极管，包括阳极、阴极以及位于所述阳极和所述阴极之间的量子点发光层，所述阴极与所述量子点发光层之间设置有电子传输层，所述电子传输层由本申请所述的复合材料组成。In a third aspect, a quantum dot light-emitting diode is provided, including an anode, a cathode, and a quantum dot light-emitting layer located between the anode and the cathode, and an electron transport layer is provided between the cathode and the quantum dot light-emitting layer The electron transport layer is composed of the composite material described in this application.

本申请实施例提供的量子点发光二极管的有益效果在于：该量子点发光二极管中的电子传输层由本申请特有的复合材料组成，该复合材料具有很好的晶体结构电学性能，可以提高电子迁移率，减少n型金属氧化物纳米颗粒表面缺陷，因此其组成的电子传输层提高了该器件的电子有效利用率，减少缺陷复合，增强电子注入，减少量子点发光层和电子传输层的界面的电荷积累，从而提高了QLED器件的效率和寿命。The beneficial effect of the quantum dot light-emitting diode provided by the embodiments of the application is that the electron transport layer in the quantum dot light-emitting diode is composed of a composite material unique to the application, and the composite material has good electrical properties of a crystal structure and can improve electron mobility. , Reduce the surface defects of n-type metal oxide nanoparticles, so the electron transport layer composed of it improves the effective utilization of electrons of the device, reduces defect recombination, enhances electron injection, and reduces the charge at the interface between the quantum dot light-emitting layer and the electron transport layer Accumulation, thereby improving the efficiency and lifespan of QLED devices.

附图说明Description of the drawings

图1为本申请实施例的复合材料的制备方法流程图；Fig. 1 is a flow chart of a method for preparing a composite material according to an embodiment of the application;

图2为本申请实施例的量子点发光二极管的结构示意图。FIG. 2 is a schematic diagram of the structure of a quantum dot light-emitting diode according to an embodiment of the application.

本发明的实施方式Embodiments of the present invention

为了使本申请的目的、技术方案及优点更加清楚明白，以下结合附图及实施例，对本申请进行进一步详细说明。应当理解，此处所描述的具体实施例仅用以解释本申请，并不用于限定本申请。In order to make the purpose, technical solutions, and advantages of this application clearer, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present application, and are not used to limit the present application.

本申请一些实施例提供了一种复合材料，所述复合材料包括n型金属氧化物纳米颗粒和连接在所述n型金属氧化物纳米颗粒表面的如下式I所示的有机分子，所述有机分子上的羧基结合在所述n型金属氧化物纳米颗粒表面；Some embodiments of the present application provide a composite material, the composite material includes n-type metal oxide nanoparticles and organic molecules shown in the following formula I connected to the surface of the n-type metal oxide nanoparticles, the organic The carboxyl group on the molecule is bound to the surface of the n-type metal oxide nanoparticle;

本申请实施例提供的复合材料包括n型金属氧化物纳米颗粒和与该n型金属氧化物纳米颗粒连接的式I所示的有机分子，该有机分子中的羧基基团可以与n型金属氧化物纳米颗粒表面的金属离子结合，因该有机分子为二羧酸类小分子，如此该有机分子通过羧基可以与两个n型金属氧化物纳米颗粒连接，从而将n型金属氧化物纳米颗粒相互连接起来构成网络状结构。这些网状连结结构不仅有效缩短了粒子间距，而且保证纳米颗粒之间不会团聚，同时双极性基团的有机分子结合在n型金属氧化物纳米颗粒表面，可以降低其表面缺陷，增强纳米粒子间的电子传导能力，从而提高了复合材料的电子迁移率，因此增强了复合材料的电子传输能力。The composite material provided by the embodiments of the present application includes n-type metal oxide nanoparticles and organic molecules of formula I connected to the n-type metal oxide nanoparticles. The carboxyl groups in the organic molecules can be oxidized with the n-type metal oxide nanoparticles. Because the organic molecule is a small dicarboxylic acid molecule, the organic molecule can be connected to two n-type metal oxide nanoparticles through the carboxyl group, thereby connecting the n-type metal oxide nanoparticles to each other. Connected to form a network-like structure. These network connection structures not only effectively shorten the particle spacing, but also ensure that the nanoparticles will not agglomerate. At the same time, the organic molecules of the bipolar group are bound to the surface of the n-type metal oxide nanoparticles, which can reduce the surface defects and enhance the nanoparticles. The electron conductivity between particles increases the electron mobility of the composite material, thus enhancing the electron transport ability of the composite material.

在一些实施例中，所述有机分子的R ₁中，n＝2～20；具体地，n可以为2、4、6、9、12、14、16、18、20等；进一步地，所述有机分子的R ₁中，n＝4～9，该碳原子数范围内的无支链的直链R ₁，可以更好地将n型金属氧化物纳米颗粒连接。在一个实施例中，所述有机分子与所述n型金属氧化物纳米颗粒的质量比为(0.1～5)：30，具体地，有机分子与n型金属氧化物纳米颗粒的质量比可以为0.1:30、0.5:30、1:30、2:30、4:30、5:30等；进一步地，有机分子与所述n型金属氧化物纳米颗粒的质量比为(1～4)：30；在该质量比范围内掺杂式I所示的有机分子，可以更好地提升复合材料的电子传输性能。 In some embodiments, in R ₁ of the organic molecule, n=2-20; specifically, n may be 2, 4, 6, 9, 12, 14, 16, 18, 20, etc.; further, In the R ₁ of the organic molecule, n=4-9, and the unbranched straight chain R ₁ within the range of the number of carbon atoms can better connect the n-type metal oxide nanoparticles. In an embodiment, the mass ratio of the organic molecules to the n-type metal oxide nanoparticles is (0.1-5): 30, specifically, the mass ratio of the organic molecules to the n-type metal oxide nanoparticles may be 0.1:30, 0.5:30, 1:30, 2:30, 4:30, 5:30, etc.; further, the mass ratio of organic molecules to the n-type metal oxide nanoparticles is (1 to 4): 30; Doping the organic molecules shown in formula I within this mass ratio range can better improve the electron transport performance of the composite material.

在一些实施例中，所述n型金属氧化物纳米颗粒选自锌的氧化物纳米颗粒、钛的氧化物纳米颗粒、锡的氧化物纳米颗粒、锆的氧化物纳米颗粒和铝掺杂锌的氧化物纳米颗粒中的一种或多种，具体地，锌的氧化物如ZnO、钛的氧化物如TiO ₂、锡的氧化物如SnO ₂、锆的氧化物如ZrO ₂、铝掺杂锌的氧化物如AlZnO。进一步地，所述n型金属氧化物纳米颗粒选自ZnO纳米颗粒，ZnO具有很好的电子传输性能，但是ZnO纳米粒子在旋涂成膜后的膜结构常表现为无序的松散结构，含有大量的各种缺陷，如微孔等。而且ZnO与量子点表面呈非极性的配体接触差，使得电子注入困难。因此，将式I所示的有机分子结合在氧化锌纳米颗粒表面，可以降低其表面缺陷，增强纳米粒子间的电子传导能力，从而提高了氧化锌的电子传输性能。 In some embodiments, the n-type metal oxide nanoparticles are selected from zinc oxide nanoparticles, titanium oxide nanoparticles, tin oxide nanoparticles, zirconium oxide nanoparticles, and aluminum-doped zinc oxide nanoparticles. One or more of oxide nanoparticles, specifically, zinc oxides such as ZnO, titanium oxides such as TiO ₂ , tin oxides such as SnO ₂ , zirconium oxides such as ZrO ₂ , aluminum-doped zinc The oxides such as AlZnO. Further, the n-type metal oxide nanoparticles are selected from ZnO nanoparticles. ZnO has good electron transport properties, but the film structure of ZnO nanoparticles after spin-coating is often shown as a disordered loose structure, containing A large number of various defects, such as micropores, etc. In addition, ZnO has poor contact with non-polar ligands on the surface of quantum dots, making electron injection difficult. Therefore, combining the organic molecules represented by formula I on the surface of zinc oxide nanoparticles can reduce surface defects and enhance the electronic conductivity between the nanoparticles, thereby improving the electron transport performance of zinc oxide.

在一些实施例中，所述复合材料由所述n型金属氧化物纳米颗粒和所述有机分子组成。In some embodiments, the composite material is composed of the n-type metal oxide nanoparticles and the organic molecules.

另一方面，本申请实施例还提供了一种复合材料的制备方法，如图1所示，该制备方法包括如下步骤：On the other hand, the embodiment of the present application also provides a preparation method of a composite material. As shown in FIG. 1, the preparation method includes the following steps:

S01：提供n型金属氧化物纳米颗粒和式II所示的二羧酸单酯有机物；S01: Provide n-type metal oxide nanoparticles and dicarboxylic acid monoester organic compounds represented by formula II;

S02：将所述n型金属氧化物纳米颗粒和二羧酸单酯有机物溶于极性溶剂中，进行加热处理，得到混合溶液；S02: Dissolve the n-type metal oxide nanoparticles and the organic dicarboxylic acid monoester in a polar solvent, and perform heating treatment to obtain a mixed solution;

S03：将所述混合溶液进行固液分离，得到所述复合材料；S03: Perform solid-liquid separation of the mixed solution to obtain the composite material;

本申请实施例提供的复合材料的制备方法，通过将n型金属氧化物纳米颗粒、式II所示的二羧酸单酯有机物溶于极性溶剂中进行加热处理，式II所示的二羧酸单酯有机物水解形成式I所示的有机分子，因此后续固液分离得到的复合材料中，该有机分子通过羧基可以与两个n型金属氧化物纳米颗粒结合，使该有机分子将n型金属氧化物纳米颗粒相互连接起来；该制备方法不仅工艺简单，成本低廉，可大规模制备，而且这样的制备方法得到的复合材料不仅有效缩短了粒子间距，而且保证纳米颗粒之间不会团聚，同时双极性基团的有机分子结合在n型金属氧化物纳米颗粒表面，可以降低其表面缺陷，增强纳米粒子间的电子传导能力，从而提高了复合材料的电子迁移率，因此增强了复合材料的电子传输能力。The preparation method of the composite material provided by the embodiment of the application is by dissolving n-type metal oxide nanoparticles and the dicarboxylic acid monoester organic compound represented by formula II in a polar solvent for heating treatment, the dicarboxylic acid represented by formula II The acid monoester organic matter is hydrolyzed to form an organic molecule represented by formula I. Therefore, in the composite material obtained by subsequent solid-liquid separation, the organic molecule can be combined with two n-type metal oxide nanoparticles through the carboxyl group, so that the organic molecule will be n-type The metal oxide nanoparticles are connected to each other; the preparation method is not only simple in process, low in cost, and can be prepared on a large scale, and the composite material obtained by such a preparation method not only effectively shortens the particle distance, but also ensures that the nanoparticles will not agglomerate. At the same time, the organic molecules of the bipolar group are bound to the surface of the n-type metal oxide nanoparticles, which can reduce the surface defects and enhance the electronic conductivity between the nanoparticles, thereby increasing the electron mobility of the composite material, thereby enhancing the composite material The ability of electronic transmission.

在一些实施例中，本申请实施例提供的复合材料由上述制备方法得到，所述复合材料包括n型金属氧化物纳米颗粒和与所述n型金属氧化物纳米颗粒连接的如式I所示的有机分子，所述有机分子上的两个羧基可以分别结合n型金属氧化物纳米颗粒表面的金属离子，从而使该有机分子将n型金属氧化物纳米颗粒相互连接起来形成网络结构，具体制备步骤如上述所示。In some embodiments, the composite material provided in the embodiments of the present application is obtained by the above-mentioned preparation method, and the composite material includes n-type metal oxide nanoparticles and the n-type metal oxide nanoparticles connected to the n-type metal oxide nanoparticles as shown in formula I The two carboxyl groups on the organic molecules can respectively bind to the metal ions on the surface of the n-type metal oxide nanoparticles, so that the organic molecules connect the n-type metal oxide nanoparticles to form a network structure, which is specifically prepared The steps are shown above.

上述步骤S01中，式II所示的二羧酸单酯有机物，R ₁中，n＝2～20；R ₂中，m＝2～20。该碳原子数范围内的无支链的直链R ₁，可以更好地将n型金属氧化物纳米颗粒连接。该碳原子数范围内的无支链的直链R ₂，可以更好地水解形成式I所示的双极性基团的有机分子。所述n型金属氧化物纳米颗粒选自锌的氧化物纳米颗粒、钛的氧化物纳米颗粒、锡的氧化物纳米颗粒、锆的氧化物纳米颗粒和铝掺杂锌的氧化物纳米颗粒中的一种或多种。 The above-described step S01, dicarboxylic acid monoester represented by Formula II organics, R in _{1, n = 2 ~ 20;} R 2 are, m = 2 ~ 20. _{The unbranched straight chain R 1} within the range of the number of carbon atoms can better connect the n-type metal oxide nanoparticles. _{The unbranched straight chain R 2} within the range of carbon atoms can be better hydrolyzed to form the organic molecule of the bipolar group represented by formula I. The n-type metal oxide nanoparticles are selected from zinc oxide nanoparticles, titanium oxide nanoparticles, tin oxide nanoparticles, zirconium oxide nanoparticles, and aluminum-doped zinc oxide nanoparticles One or more.

上述步骤S02中，n型金属氧化物纳米颗粒、二羧酸单酯有机物在极性溶剂加热溶解得到混合溶液，而二羧酸单酯有机物水解形成式I所示的双极性基团的有机分子，所述加热处理的条件包括：温度为60～120℃，时间为30min～4h，上述条件下二羧酸单酯有机物可以更好地水解。例如，混合溶液是辛二酸单甲酯和醋酸锌的脂肪酸溶液，加热水解后辛二酸单甲酯转变为辛二酸，然后与n型金属氧化物纳米颗粒结合。其中，所述极性溶剂包括乙醇、甲醇、水、N,N-二甲基甲酰胺、N,N-二甲基乙酰胺中的一种或多种。In the above step S02, the n-type metal oxide nanoparticles and the dicarboxylic acid monoester organic matter are heated and dissolved in a polar solvent to obtain a mixed solution, and the dicarboxylic acid monoester organic matter is hydrolyzed to form the organic bipolar group represented by formula I. Molecule, the conditions of the heat treatment include: a temperature of 60-120°C and a time of 30min-4h. Under the above conditions, the organic dicarboxylic acid monoester can be better hydrolyzed. For example, the mixed solution is a fatty acid solution of monomethyl suberate and zinc acetate. After heating and hydrolyzing, the monomethyl suberate is converted into suberic acid and then combined with n-type metal oxide nanoparticles. Wherein, the polar solvent includes one or more of ethanol, methanol, water, N,N-dimethylformamide, and N,N-dimethylacetamide.

在一些实施例中，上述加入的所述二羧酸单酯有机物与所述n型金属氧化物纳米颗粒的质量比为(0.1～5)：30；在该质量比范围内可以更好地提升复合材料的电子传输性能。In some embodiments, the mass ratio of the added organic dicarboxylic acid monoester to the n-type metal oxide nanoparticles is (0.1-5): 30; it can be better improved within the range of the mass ratio The electron transport properties of composite materials.

上述骤S03中，所述固液分离的步骤包括退火结晶处理，例如所述固液分离包括在温度为80～120℃的条件下退火结晶，例如温度可以80℃、100℃、120℃等；进一步地，退火时间为20min～40min，例如可以是20min、30min、40min等。在一具体实施例中，为了得到该复合材料薄膜，将混合溶液沉积在基板上进行退火结晶处理，从而得到复合材料膜层，可以作电子传输膜层。In the above step S03, the step of solid-liquid separation includes annealing crystallization treatment, for example, the solid-liquid separation includes annealing crystallization at a temperature of 80 to 120°C, for example, the temperature can be 80°C, 100°C, 120°C, etc.; Further, the annealing time is 20min-40min, for example, it can be 20min, 30min, 40min, etc. In a specific embodiment, in order to obtain the composite material film, the mixed solution is deposited on the substrate for annealing and crystallization treatment, thereby obtaining a composite material film layer, which can be used as an electron transport film layer.

退火后得到的复合材料膜层可以提高复合材料的成膜结晶性，从而提高空穴传输。现有n型金属氧化物纳米颗粒在成膜前都是以水合粒子的形态存在，水合粒子比本身的粒子大小大近一倍，在成膜过程中成膜溶剂蒸发以后，没有相互吸引的作用力的作用下，间距比较大；而且现有技术中合成的n型金属氧化物纳米颗粒、以及溶液法成膜技术通常使得n型金属氧化物纳米颗粒组成的电子传输层结构无序、具有较多的微孔缺陷且膜结晶度低。The composite material film layer obtained after annealing can improve the film-forming crystallinity of the composite material, thereby improving hole transport. Existing n-type metal oxide nanoparticles exist in the form of hydrated particles before film formation. The hydrated particles are nearly twice the size of their own particles. After the film-forming solvent evaporates during the film-forming process, there is no mutual attraction. Under the action of force, the spacing is relatively large; and the n-type metal oxide nanoparticles synthesized in the prior art and the solution method film formation technology usually make the electron transport layer composed of n-type metal oxide nanoparticles disorderly and relatively Many microporous defects and low film crystallinity.

本申请实施例通过掺杂式I所示的有机分子，对n型金属氧化物纳米颗粒进行改性修饰，改善ETL 层膜质量和结晶性能，一方面在成膜结晶过程中无支链的直链二羧酸单酯有机物能够完全水解形成式I所示的双极性基团的有机分子，该有机分子能够将相邻金属氧化物纳米颗粒(如ZnO纳米颗粒)相互连结起来，形成n型金属氧化物纳米颗粒-式I所示有机分子-n型金属氧化物纳米颗粒的结构，从而实现将n型金属氧化物纳米颗粒连接起来构成网络状结构；另一方面，双极性基团的存在同样也有效地填补了n型金属氧化物纳米颗粒表面缺陷，减少了电子在电子传输膜层缺陷跃迁的损失，减少了层内电子积累，增强了纳米粒子间的电子传导能力，提高了氧化锌层的电子迁移率。因此，上述制备方法得到的复合材料提高电子在界面的传导和复合能力，提高载流子在界面间的传输效率，平衡器件的空穴和电子注入速率，提高器件的亮度和寿命。The embodiment of the application modifies the n-type metal oxide nanoparticles by doping the organic molecules represented by formula I to improve the film quality and crystallization performance of the ETL layer. The chain dicarboxylic acid monoester organics can be completely hydrolyzed to form organic molecules of the bipolar group shown in formula I, which can connect adjacent metal oxide nanoparticles (such as ZnO nanoparticles) to each other to form an n-type The structure of metal oxide nanoparticles-organic molecules represented by formula I-n-type metal oxide nanoparticles, so as to realize the connection of n-type metal oxide nanoparticles to form a network structure; on the other hand, the structure of the bipolar group Existence also effectively fills up the surface defects of n-type metal oxide nanoparticles, reduces the loss of electrons in the electron transport film defect transition, reduces the accumulation of electrons in the layer, enhances the electron conductivity between nanoparticles, and improves oxidation Electron mobility of the zinc layer. Therefore, the composite material obtained by the above preparation method improves the conduction and recombination ability of electrons at the interface, improves the transport efficiency of carriers between the interface, balances the hole and electron injection rate of the device, and improves the brightness and life of the device.

本申请实施例还提供一种上述复合材料或上述复合材料的制备方法得到的复合材料作为电子传输材料的应用。因本申请实施例提供的上述复合材料晶体平面电学性能更加优异，电子迁移率更高，通过在n型金属氧化物纳米颗粒中掺杂双极性基团的有机分子形成平面层状晶体，提升电子传输层的电学性能，因此该复合材料可以用作电子传输材料，具体用于量子点发光二极管的电子传输层。The embodiments of the present application also provide an application of the above-mentioned composite material or the composite material obtained by the above-mentioned composite material preparation method as an electron transport material. Because the above-mentioned composite material crystals provided by the embodiments of the present application have more excellent planar electrical properties and higher electron mobility, the planar layered crystals are formed by doping organic molecules with bipolar groups in the n-type metal oxide nanoparticles to improve The electrical properties of the electron transport layer, so the composite material can be used as an electron transport material, specifically for the electron transport layer of quantum dot light-emitting diodes.

最后，本申请实施例提供一种量子点发光二极管，包括阳极、阴极以及位于所述阳极和所述阴极之间的量子点发光层，所述阴极与所述量子点发光层之间设置有电子传输层，所述电子传输层由本申请实施例所述的复合材料组成。Finally, the embodiments of the present application provide a quantum dot light-emitting diode, which includes an anode, a cathode, and a quantum dot light-emitting layer located between the anode and the cathode, and electrons are arranged between the cathode and the quantum dot light-emitting layer. The transport layer, the electron transport layer is composed of the composite material described in the embodiments of the present application.

本申请实施例提供的量子点发光二极管中，其电子传输层由本申请实施例特有的复合材料组成，该复合材料具有很好的晶体结构电学性能，可以提高电子迁移率，减少n型金属氧化物纳米颗粒表面缺陷，因此该器件提高了电子的有效利用率，减少缺陷复合，增强电子注入，减少量子点发光层和空穴传输层的界面的电荷积累，提高QLED器件的效率和寿命。In the quantum dot light-emitting diode provided by the embodiment of the application, the electron transport layer is composed of a composite material unique to the embodiment of the application. The composite material has good electrical properties of a crystal structure, can improve electron mobility, and reduce n-type metal oxides. Nanoparticle surface defects, so the device improves the effective utilization of electrons, reduces defect recombination, enhances electron injection, reduces charge accumulation at the interface between the quantum dot light-emitting layer and the hole transport layer, and improves the efficiency and life of the QLED device.

在一写实施例中，电子传输层与阴极之间还设置有电子注入层。在另一写实施例中，量子点发光层与阳极之间设置有空穴功能层，如空穴传输层，或层叠的空穴注入层和空穴传输层，其中空穴注入层与阳极相邻。In one embodiment, an electron injection layer is also provided between the electron transport layer and the cathode. In another embodiment, a hole function layer, such as a hole transport layer, or a stacked hole injection layer and a hole transport layer is provided between the quantum dot light-emitting layer and the anode, wherein the hole injection layer is in phase with the anode. adjacent.

本申请实施例提供的量子点发光二极管包括正置结构和倒置结构。The quantum dot light-emitting diode provided by the embodiment of the present application includes an upright structure and an inverted structure.

在一种实施方式中，正置结构量子点发光二极管包括相对设置的阳极和阴极的层叠结构，设置在所述阳极和所述阴极之间的量子点发光层，设置在所述阴极和所述量子点发光层之间的电子传输层，且所述阳极设置在衬底上。进一步的，在所述阴极和所述电子传输层之间还可以设置电子注入层，所述阴极和所述量子点发光层之间还可以设置空穴阻挡层等电子功能层；在所述阳极和所述量子点发光层之间还可以设置空穴传输层、空穴注入层和电子阻挡层等空穴功能层。在一些正置结构器件的实施例中，所述量子点发光二极管包括衬底，设置在所述衬底表面的阳极，设置在阳极表面的所述空穴注入层，设置在所述空穴注入层表面的空穴传输层，设置在所述空穴传输层表面的量子点发光层，设置在量子点发光层表面的电子传输层和设置在电子传输层表面的阴极。In one embodiment, the upright structure quantum dot light-emitting diode includes a laminated structure of an anode and a cathode disposed oppositely, and a quantum dot light-emitting layer disposed between the anode and the cathode is disposed on the cathode and the cathode. The electron transport layer between the quantum dot light-emitting layers, and the anode is disposed on the substrate. Further, an electron injection layer may be provided between the cathode and the electron transport layer, and an electron functional layer such as a hole blocking layer may be provided between the cathode and the quantum dot light-emitting layer; A hole function layer such as a hole transport layer, a hole injection layer, and an electron blocking layer may also be provided between the quantum dot light-emitting layer and the quantum dot light-emitting layer. In some embodiments of the upright structure device, the quantum dot light emitting diode includes a substrate, an anode disposed on the surface of the substrate, the hole injection layer disposed on the surface of the anode, and the hole injection layer is disposed on the hole injection layer. The hole transport layer on the surface of the layer, the quantum dot light emitting layer provided on the surface of the hole transport layer, the electron transport layer provided on the surface of the quantum dot light emitting layer, and the cathode provided on the surface of the electron transport layer.

在一种实施方式中，倒置结构量子点发光二极管包括相对设置的阳极和阴极的叠层结构，设置在所述阳极和所述阴极之间的量子点发光层，设置在所述阴极和所述量子点发光层之间的电子传输层，且所述阴极设置在衬底上。进一步的，在所述阴极和所述电子传输层之间还可以设置电子注入层，所述阴极和所述量子点发光层之间还可以设置空穴阻挡层等电子功能层；在所述阳极和所述量子点发光层之间还可以设置空穴传输层、空穴注入层和电子阻挡层等空穴功能层。在一些倒置结构器件的实施例中，所述量子点发光二极管包括衬底，设置在所述衬底表面的阴极，设置在阴极表面的所述电子传输层，设置在所述电子传输层表面的量子点发光层，设置在所述量子点发光层表面的空穴传输层，设置在空穴传输层表面的空穴注入层和设置在空穴注入层表面的阳极。In one embodiment, the inverted structure quantum dot light-emitting diode includes a stacked structure of an anode and a cathode disposed oppositely, and a quantum dot light-emitting layer disposed between the anode and the cathode is disposed on the cathode and the cathode. The electron transport layer between the quantum dot light-emitting layers, and the cathode is disposed on the substrate. Further, an electron injection layer may be provided between the cathode and the electron transport layer, and an electron functional layer such as a hole blocking layer may be provided between the cathode and the quantum dot light-emitting layer; A hole function layer such as a hole transport layer, a hole injection layer, and an electron blocking layer may also be provided between the quantum dot light-emitting layer and the quantum dot light-emitting layer. In some embodiments of the inverted structure device, the quantum dot light emitting diode includes a substrate, a cathode disposed on the surface of the substrate, the electron transport layer disposed on the surface of the cathode, and the electron transport layer disposed on the surface of the electron transport layer. A quantum dot light-emitting layer, a hole transport layer provided on the surface of the quantum dot light-emitting layer, a hole injection layer provided on the surface of the hole transport layer, and an anode provided on the surface of the hole injection layer.

相应地，一种量子点发光二极管的制备方法，该量子点发光二极管的制备方法包括如下步骤：Correspondingly, a method for manufacturing a quantum dot light-emitting diode includes the following steps:

E01：提供基板；E01: Provide substrate;

E02：将本申请实施例所述的复合材料或者制备方法得到的复合材料沉积在所述基板上，得到电子传输层。E02: Deposit the composite material described in the embodiment of the application or the composite material obtained by the preparation method on the substrate to obtain an electron transport layer.

本申请实施例提供的量子点发光二极管的制备方法将本申请实施例的特有复合材料制备成器件的电子传输层，因该复合材料具有很好的电子传输性能，因此复合材料作为电子传输层可以提高器件发光效率和寿命。The method for preparing quantum dot light-emitting diodes provided in the embodiments of the application prepares the unique composite material of the embodiments of the application into the electron transport layer of the device. Because the composite material has good electron transport properties, the composite material can be used as the electron transport layer. Improve the luminous efficiency and lifetime of the device.

具体地，一种QLED器件制备包括如下步骤：Specifically, the preparation of a QLED device includes the following steps:

(1)提供一衬底基板，基板上形成阳极；(1) Provide a base substrate on which an anode is formed;

(2)在阳极上形成空穴注入层；(2) A hole injection layer is formed on the anode;

(3)在空穴注入层上形成空穴传输层。(3) A hole transport layer is formed on the hole injection layer.

(4)在所述空穴传输层上沉淀量子点发光层；(4) Precipitating a quantum dot light-emitting layer on the hole transport layer;

(5)在量子点发光层上沉淀电子传输层；(5) Precipitating an electron transport layer on the quantum dot light-emitting layer;

(6)在电子传输层上形成阴极。(6) A cathode is formed on the electron transport layer.

衬底可选为钢性衬底或柔性衬底，包括但不限于玻璃、硅晶片等。The substrate may be a rigid substrate or a flexible substrate, including but not limited to glass, silicon wafer, and the like.

阳极可选为导电金属氧化物，包括但不限于氧化锌、氧化铟、氧化锡、氧化铟锡(ITO)等。The anode may be a conductive metal oxide, including but not limited to zinc oxide, indium oxide, tin oxide, indium tin oxide (ITO), and the like.

空穴注入层可选为聚噻吩、WoO ₃等。 The hole injection layer can be polythiophene, WoO _3, and the like.

空穴传输层可选为TFB、TPD等。The hole transport layer can be TFB, TPD, etc.

发光层材料可选为诸如CdS等的II-VI族、诸如GaN等的III-V族或诸如SnS等IV-VI族。The material of the light-emitting layer may be group II-VI such as CdS, group III-V such as GaN, or group IV-VI such as SnS.

阴极可选为金属或合金，包括但不限于铝、银等。The cathode can be a metal or alloy, including but not limited to aluminum, silver, and the like.

所述阳极的厚度为20～200nm；所述空穴注入层的厚度为20～200nm；空穴传输层的厚度为30～180nm；所述量子点混合发光层的总厚度为30～180nm。所述电子传输层的厚度为10～180nm；所述阴极的厚度为40～190nm。The thickness of the anode is 20-200nm; the thickness of the hole injection layer is 20-200nm; the thickness of the hole transport layer is 30-180nm; the total thickness of the quantum dot hybrid light-emitting layer is 30-180nm. The thickness of the electron transport layer is 10-180 nm; the thickness of the cathode is 40-190 nm.

本申请先后进行过多次试验，现举一部分试验结果作为参考对申请进行进一步详细描述，下面结合具体实施例进行详细说明。This application has been tested for many times, and a part of the test results will now be used as a reference to further describe the application in detail, and the detailed description will be given below in conjunction with specific examples.

实施例1Example 1

本实施例提供一种QLED器件，其结构如图2所示，该QLED器件从下而上依次包括衬底1、阳极2、空穴注入层3、空穴传输层4、量子点发光层5、电子传输层6、阴极7。其中，衬底1的材料为玻璃片，阳极2的材料为ITO基板，空穴注入层3的材料为PEDOT：PSS，空穴传输层4的材料为TFB，量子点发光层5的材料为CdZnSe/ZnSe量子点，电子传输层6的材料为辛二酸掺杂修饰ZnO的复合材料，阴极7的材料为Al。This embodiment provides a QLED device whose structure is shown in FIG. 2. The QLED device includes a substrate 1, an anode 2, a hole injection layer 3, a hole transport layer 4, and a quantum dot light emitting layer 5 from bottom to top. , Electron transport layer 6, cathode 7. Among them, the material of the substrate 1 is a glass sheet, the material of the anode 2 is an ITO substrate, the material of the hole injection layer 3 is PEDOT:PSS, the material of the hole transport layer 4 is TFB, and the material of the quantum dot light-emitting layer 5 is CdZnSe /ZnSe quantum dots, the material of the electron transport layer 6 is a composite material of suberic acid doped and modified ZnO, and the material of the cathode 7 is Al.

该器件的制备方法包括如下步骤：The preparation method of the device includes the following steps:

1.将TFB溶液沉积于空穴注入层(PEDOT：PSS)上，沉积条件为3000r/min旋涂30s，再于150℃下加热30min完成结晶，得到空穴传输层。1. Deposit the TFB solution on the hole injection layer (PEDOT: PSS), the deposition condition is 3000r/min spin coating for 30s, and then heat at 150°C for 30min to complete the crystallization to obtain the hole transport layer.

2.将CdZnSe/ZnSe量子点沉积于空穴传输层上，在一定转数3000r/min旋涂30s，得到量子点发光层。2. Depositing the CdZnSe/ZnSe quantum dots on the hole transport layer, and spin-coating for 30s at a certain number of revolutions of 3000r/min to obtain the quantum dot light-emitting layer.

3.沉积电子传输层(ETL)，3. Deposit the electron transport layer (ETL),

室温，向采用乙醇溶解的ZnO溶液中加入一定量辛二酸单甲酯的正辛酸溶液。所掺杂二羧酸单酯与ZnO材料的质量之比为1:30，80℃加热2h实现二羧酸单酯完全水解形成辛二酸，得到溶液1。将溶液1以3000r/min旋涂30s后，于80℃加热30min，得到电子传输层。At room temperature, add a certain amount of n-octanoic acid solution of monomethyl suberate to the ZnO solution dissolved in ethanol. The mass ratio of the doped dicarboxylic acid monoester to the ZnO material is 1:30, and the dicarboxylic acid monoester is completely hydrolyzed to form suberic acid by heating at 80° C. for 2 hours, and solution 1 is obtained. After the solution 1 was spin-coated at 3000 r/min for 30 s, it was heated at 80° C. for 30 min to obtain an electron transport layer.

4.然后蒸镀Al电极，采用电子胶封装得到QLED器件。4. Then the Al electrode is evaporated, and the QLED device is obtained by packaging with electronic glue.

实施例2Example 2

本实施例提供一种QLED器件，其结构如图2所示，该QLED器件从下而上依次包括衬底1、阳极2、空穴注入层3、空穴传输层4、量子点发光层5、电子传输层6、阴极7。其中，衬底1的材料为玻璃片，阳极2的材料为ITO基板，空穴注入层3的材料为PEDOT：PSS，空穴传输层4的材料为TFB，量子点发光层5的材料为CdZnSe/ZnSe/ZnS量子点，电子传输层6的材料为庚二酸掺杂修饰ZnO的复合材料，阴极7的材料为Al。This embodiment provides a QLED device whose structure is shown in FIG. 2. The QLED device includes a substrate 1, an anode 2, a hole injection layer 3, a hole transport layer 4, and a quantum dot light emitting layer 5 from bottom to top. , Electron transport layer 6, cathode 7. Among them, the material of the substrate 1 is a glass sheet, the material of the anode 2 is an ITO substrate, the material of the hole injection layer 3 is PEDOT:PSS, the material of the hole transport layer 4 is TFB, and the material of the quantum dot light-emitting layer 5 is CdZnSe /ZnSe/ZnS quantum dots, the material of the electron transport layer 6 is a composite material of pimelic acid doped and modified ZnO, and the material of the cathode 7 is Al.

2.将CdZnSe/ZnSe/ZnS量子点沉积于空穴传输层上，在一定转数2000r/min旋涂30s，得到量子点发光层。2. Depositing CdZnSe/ZnSe/ZnS quantum dots on the hole transport layer, spin-coating at a certain speed of 2000r/min for 30s to obtain the quantum dot light-emitting layer.

3.沉积电子传输层(ETL)，3. Deposit the electron transport layer (ETL),

室温，向采用乙醇溶解的ZnO溶液中加入一定量庚二酸单甲酯的正辛酸溶液。所掺杂二羧酸单酯与ZnO材料的质量之比为2:30，80℃加热2h实现二羧酸单酯完全水解形成庚二酸，得到溶液1。将溶液1以3000r/min旋涂30s后，于80℃加热30min，得到电子传输层。At room temperature, add a certain amount of n-octanoic acid solution of monomethyl pimelate to the ZnO solution dissolved in ethanol. The mass ratio of the doped dicarboxylic acid monoester to the ZnO material is 2:30, heated at 80°C for 2 hours to achieve complete hydrolysis of the dicarboxylic acid monoester to form pimelic acid, and solution 1 is obtained. After the solution 1 was spin-coated at 3000 r/min for 30 s, it was heated at 80° C. for 30 min to obtain an electron transport layer.

实施例3Example 3

本实施例提供一种QLED器件，其结构如图2所示，该QLED器件从下而上依次包括衬底1、阳极2、空穴注入层3、空穴传输层4、量子点发光层5、电子传输层6、阴极7。其中，衬底1的材料为玻璃片，阳极2的材料为ITO基板，空穴注入层3的材料为PEDOT：PSS，空穴传输层4的材料为TFB，量子点发光层5的材料为CdZnSe/ZnSe/CdZnS量子点，电子传输层6的材料为丁二酸掺杂修饰ZnO的复合材料，阴极7的材料为Al。This embodiment provides a QLED device whose structure is shown in FIG. 2. The QLED device includes a substrate 1, an anode 2, a hole injection layer 3, a hole transport layer 4, and a quantum dot light emitting layer 5 from bottom to top. , Electron transport layer 6, cathode 7. Among them, the material of the substrate 1 is a glass sheet, the material of the anode 2 is an ITO substrate, the material of the hole injection layer 3 is PEDOT:PSS, the material of the hole transport layer 4 is TFB, and the material of the quantum dot light-emitting layer 5 is CdZnSe /ZnSe/CdZnS quantum dots, the material of the electron transport layer 6 is a composite material of succinic acid doped and modified ZnO, and the material of the cathode 7 is Al.

2.将CdZnSe/ZnSe/CdZnS量子点沉积于空穴传输层上，在一定转数4000r/min旋涂30s，得到量子点发光层。2. Depositing the CdZnSe/ZnSe/CdZnS quantum dots on the hole transport layer, spin-coating at a certain speed of 4000r/min for 30s to obtain the quantum dot light-emitting layer.

3.沉积电子传输层(ETL)，3. Deposit the electron transport layer (ETL),

室温，向采用乙醇溶解的ZnO溶液中加入一定量丁二酸单甲酯的正辛酸溶液。所掺杂二羧酸单酯与ZnO材料的质量之比为2:30，80℃加热2h实现二羧酸单酯完全水解形成丁二酸，得到溶液1。将溶液1以3000r/min旋涂30s后于80℃加热60min，得到电子传输层。At room temperature, add a certain amount of n-octanoic acid solution of monomethyl succinate to the ZnO solution dissolved in ethanol. The mass ratio of the doped dicarboxylic acid monoester to the ZnO material is 2:30, and the dicarboxylic acid monoester is completely hydrolyzed to form succinic acid by heating at 80° C. for 2 hours, and solution 1 is obtained. The solution 1 was spin-coated at 3000r/min for 30s and then heated at 80°C for 60min to obtain an electron transport layer.

实施例4Example 4

本实施例提供一种QLED器件，其结构如图2所示，该QLED器件从下而上依次包括衬底1、阳极2、空穴注入层3、空穴传输层4、量子点发光层5、电子传输层6、阴极7。其中，衬底1的材料为玻璃片，阳极2的材料为ITO基板，空穴注入层3的材料为PEDOT：PSS，空穴传输层4的材料为TFB，量子点发光层5的材料为CdZnSeS/ZnS量子点，电子传输层6的材料为壬二酸掺杂修饰ZnO的复合材料，阴极7的材料为Al。This embodiment provides a QLED device whose structure is shown in FIG. 2. The QLED device includes a substrate 1, an anode 2, a hole injection layer 3, a hole transport layer 4, and a quantum dot light emitting layer 5 from bottom to top. , Electron transport layer 6, cathode 7. Among them, the material of the substrate 1 is a glass sheet, the material of the anode 2 is an ITO substrate, the material of the hole injection layer 3 is PEDOT:PSS, the material of the hole transport layer 4 is TFB, and the material of the quantum dot light-emitting layer 5 is CdZnSeS /ZnS quantum dots, the material of the electron transport layer 6 is azelaic acid doped and modified ZnO composite material, and the material of the cathode 7 is Al.

2.将CdZnSeS/ZnS量子点沉积于空穴传输层上，在一定转数4000r/min旋涂30s，得到量子点发光层。2. Depositing CdZnSeS/ZnS quantum dots on the hole transport layer, spin-coating at a certain speed of 4000r/min for 30s, to obtain the quantum dot light-emitting layer.

3.沉积电子传输层(ETL)，3. Deposit the electron transport layer (ETL),

室温，向采用乙醇溶解的ZnO溶液中加入一定量壬二酸单甲酯的正辛酸溶液。所掺杂二羧酸单酯与ZnO材料的质量之比为4:30，80℃加热2h实现二羧酸单酯完全水解形成壬二酸，得到溶液1。将溶液1以3000r/min旋涂30s后于80℃加热30min，得到电子传输层。At room temperature, add a certain amount of n-octanoic acid solution of monomethyl azelate to the ZnO solution dissolved in ethanol. The mass ratio of the doped dicarboxylic acid monoester to the ZnO material is 4:30, and the dicarboxylic acid monoester is completely hydrolyzed to form azelaic acid by heating at 80° C. for 2 hours, and solution 1 is obtained. The solution 1 was spin-coated at 3000r/min for 30s and then heated at 80°C for 30min to obtain an electron transport layer.

实施例5Example 5

本实施例提供一种QLED器件，其结构如图2所示，该QLED器件从下而上依次包括衬底1、阳极2、空穴注入层3、空穴传输层4、量子点发光层5、电子传输层6、阴极7。其中，衬底1的材料为玻璃片，阳极2的材料为ITO基板，空穴注入层3的材料为PEDOT：PSS，空穴传输层4的材料为TFB，量子点发光层5的材料为CdZnSe/ZnSe量子点，电子传输层6的材料为辛二酸掺杂修饰TiO ₂的复合材料，阴极7的材料为Al。 This embodiment provides a QLED device whose structure is shown in FIG. 2. The QLED device includes a substrate 1, an anode 2, a hole injection layer 3, a hole transport layer 4, and a quantum dot light emitting layer 5 from bottom to top. , Electron transport layer 6, cathode 7. Among them, the material of the substrate 1 is a glass sheet, the material of the anode 2 is an ITO substrate, the material of the hole injection layer 3 is PEDOT:PSS, the material of the hole transport layer 4 is TFB, and the material of the quantum dot light-emitting layer 5 is CdZnSe /ZnSe quantum dots, the material of the electron transport layer 6 is a composite material of suberic acid doped and modified TiO ₂ , and the material of the cathode 7 is Al.

3.沉积电子传输层(ETL)，3. Deposit the electron transport layer (ETL),

室温，向采用乙醇溶解的TiO ₂溶液中加入一定量辛二酸单甲酯的正辛酸溶液。所掺杂二羧酸单酯与TiO ₂材料的质量之比为1:30，80℃加热2h实现二羧酸单酯完全水解形成辛二酸，得到溶液1。将溶液1以3000r/min旋涂30s后，于80℃加热30min，得到电子传输层。 At room temperature, a certain amount of n-octanoic acid solution of monomethyl suberate is added to _{the TiO 2 solution dissolved in ethanol.} The mass ratio of the doped dicarboxylic acid monoester to the TiO ₂ material is 1:30, and the dicarboxylic acid monoester is completely hydrolyzed to form suberic acid by heating at 80° C. for 2 hours, and solution 1 is obtained. After the solution 1 was spin-coated at 3000 r/min for 30 s, it was heated at 80° C. for 30 min to obtain an electron transport layer.

实施例6Example 6

本实施例提供一种QLED器件，其结构如图2所示，该QLED器件从下而上依次包括衬底1、阳极2、空穴注入层3、空穴传输层4、量子点发光层5、电子传输层6、阴极7。其中，衬底1的材料为玻璃片，阳极2的材料为ITO基板，空穴注入层3的材料为PEDOT：PSS，空穴传输层4的材料为TFB，量子点发光层5的材料为CdZnSe/ZnSe量子点，电子传输层6的材料为辛二酸掺杂修饰SnO ₂的复合材料，阴极7的材料为Al。 This embodiment provides a QLED device whose structure is shown in FIG. 2. The QLED device includes a substrate 1, an anode 2, a hole injection layer 3, a hole transport layer 4, and a quantum dot light emitting layer 5 from bottom to top. , Electron transport layer 6, cathode 7. Among them, the material of the substrate 1 is a glass sheet, the material of the anode 2 is an ITO substrate, the material of the hole injection layer 3 is PEDOT:PSS, the material of the hole transport layer 4 is TFB, and the material of the quantum dot light-emitting layer 5 is CdZnSe /ZnSe quantum dots, the material of the electron transport layer 6 is a composite material of suberic acid doped and modified SnO _{2 and} the material of the cathode 7 is Al.

3.沉积电子传输层(ETL)，3. Deposit the electron transport layer (ETL),

室温，向采用乙醇溶解的SnO ₂溶液中加入一定量辛二酸单甲酯的正辛酸溶液。所掺杂二羧酸单酯与SnO ₂材料的质量之比为1:30，80℃加热2h实现二羧酸单酯完全水解形成辛二酸，得到溶液1。将溶液1以3000r/min旋涂30s后，于80℃加热30min，得到电子传输层。 At room temperature, add a certain amount of n-octanoic acid solution of monomethyl suberate to _{the SnO 2 solution dissolved in ethanol.} The mass ratio of the doped dicarboxylic acid monoester to the SnO ₂ material is 1:30, heated at 80° C. for 2 hours to achieve complete hydrolysis of the dicarboxylic acid monoester to form suberic acid, and solution 1 is obtained. After the solution 1 was spin-coated at 3000 r/min for 30 s, it was heated at 80° C. for 30 min to obtain an electron transport layer.

对比例1Comparative example 1

该对比例除了电子传输层的材料为无掺杂的ZnO材料外，其他制备方式均与实施例1相同。This comparative example is the same as Example 1 except that the material of the electron transport layer is undoped ZnO material.

对比例2Comparative example 2

该对比例除了电子传输层的材料为无掺杂的ZnO材料外，其他制备方式均与实施例2相同。This comparative example is the same as Example 2 except that the material of the electron transport layer is undoped ZnO material.

对比例3Comparative example 3

该对比例除了电子传输层的材料为无掺杂的ZnO材料外，其他制备方式均与实施例3相同。This comparative example is the same as Example 3 except that the material of the electron transport layer is undoped ZnO material.

对比例4Comparative example 4

该对比例除了电子传输层的材料为无掺杂的ZnO材料外，其他制备方式均与实施例4相同。This comparative example is the same as Example 4 except that the material of the electron transport layer is undoped ZnO material.

对比例5Comparative example 5

该对比例除了电子传输层的材料为无掺杂的TiO ₂材料外，其他制备方式均与实施例5相同。 This comparative example is the same as in Example 5 except that the material of the electron transport layer is undoped TiO _{2 material.}

对比例6Comparative example 6

该对比例除了电子传输层的材料为无掺杂的SnO ₂材料外，其他制备方式均与实施例6相同。 This comparative example is the same as Example 6 except that the material of the electron transport layer is undoped SnO _{2 material.}

性能测试Performance Testing

以上对比例1～6与实施例1～6中制备的量子点发光二极管进行性能测试，测试方法如下：The quantum dot light-emitting diodes prepared in Comparative Examples 1 to 6 and Examples 1 to 6 were tested for performance, and the test methods are as follows:

(1)外量子点效率：(1) External quantum dot efficiency:

注入到量子点中的电子-空穴对数转化为出射的光子数的比值，单位是％，是衡量电致发光器件优劣的一个重要参数，采用EQE光学测试仪器测定即可得到。具体计算公式如下：The ratio of the number of electron-hole pairs injected into the quantum dot into the number of emitted photons, in %, is an important parameter to measure the pros and cons of electroluminescent devices, which can be obtained by measuring with an EQE optical testing instrument. The specific calculation formula is as follows:

式中η _e为光输出耦合效率，η _r为复合的载流子数与注入载流子数的比值，χ为产生光子的激子数与总激子数的比值，K _R为辐射过程速率，K _NR为非辐射过程速率。 Where η _e is the light output coupling efficiency, η _r is the ratio of the number of recombined carriers to the number of injected carriers, χ is the ratio of the number of excitons that generate photons to the total number of excitons, and K _R is the rate of radiation process , K _{NR is the} non-radiation process rate.

测试条件：在室温下进行，空气湿度为30～60％。Test conditions: carried out at room temperature, with an air humidity of 30-60%.

(2)QLED器件寿命：(2) QLED device life:

器件在恒定电流或电压驱动下，亮度减少至最高亮度的一定比例时所需的时间，亮度下降至最高亮度的95％的时间定义为T95，该寿命为实测寿命。为缩短测试周期，器件寿命测试通常是参考OLED器件测试在高亮度下通过加速器件老化进行，并通过延伸型指数衰减亮度衰减拟合公式拟合得到高亮度下的寿命，比如：1000nit下的寿命计为T95 _1000nit。具体计算公式如下： When the device is driven by a constant current or voltage, the time required for the brightness to decrease to a certain proportion of the maximum brightness, the time for the brightness to decrease to 95% of the maximum brightness is defined as T95, and this lifetime is the measured lifetime. In order to shorten the test cycle, the device life test is usually carried out by accelerating the aging of the device with reference to the OLED device test at high brightness, and the extended exponential decay brightness decay fitting formula is used to fit the life under high brightness, such as: life under 1000nit Counted as T95 _1000nit . The specific calculation formula is as follows:

式中T95 _L为低亮度下的寿命，T95 _H为高亮度下的实测寿命，L _H为器件加速至最高亮度，L _L为1000nit，A为加速因子，对QLED而言，该取值通常为1.6～2，本实验通过测得若干组绿色QLED器件在额定亮度下的寿命得出A值为1.7。 Where T95 _L is the life under low brightness, T95 _H is the measured life under high brightness, L _H is the acceleration of the device to the highest brightness, L _L is 1000nit, and A is the acceleration factor. For QLEDs, the value is usually 1.6~2. In this experiment, the A value of 1.7 is obtained by measuring the lifetime of several groups of green QLED devices at rated brightness.

采用寿命测试***对相应器件进行寿命测试，测试条件：在室温下进行，空气湿度为30～60％。The life test system is used to carry out life test on the corresponding device, and the test conditions are: at room temperature, and the air humidity is 30-60%.

(3)电子迁移率：单位电场作用下载流子获得的平均速率，反应了载流子在电场作用下的运输能力，单位为cm ²/(V·s)。通过制备相应的纯电子型器件，然后采用空间电荷受限的电流法(SCLC)测定即可得到。纯电子型器件结构如下：阳极/电子传输层/阴极。具体计算公式如下： (3) Electron mobility: the average velocity of the carrier under the action of a unit electric field, which reflects the transport capacity of the carrier under the action of the electric field, and the unit is cm ² /(V·s). It can be obtained by preparing the corresponding pure electronic device and then using the space charge limited current method (SCLC) measurement. The pure electronic device structure is as follows: anode/electron transport layer/cathode. The specific calculation formula is as follows:

J＝(9/8)/ε _rε _oμ _eV ²/d ³ J=(9/8)/ε _r ε _o μ _e V ² /d ³

式中，J表示电流密度，单位为mA·cm-2；ε _r表示相对介电常数，ε _o表示真空介电常数，μ _e电子迁移率，单位为cm ²/(V·s)；V表示驱动电压，单位为V；d表示膜厚度，单位为m。 In the formula, J represents the current density, the unit is mA·cm-2; ε _r represents the relative permittivity, ε _o represents the vacuum permittivity, μ _e electron mobility, the unit is cm ² /(V·s); V Represents the driving voltage, the unit is V; d represents the film thickness, the unit is m.

上述测试结果如表1所示：The above test results are shown in Table 1:

表1Table 1

从上表1可见，本申请实施例提供的量子点发光二极管中，电子传输层薄膜的电子迁移率明显高于各自对应的对比例中电子传输层薄膜。而且本申请实施例提供的量子点发光二极管的外量子效率和寿命明显高于各自对应的对比例中的量子点发光二极管，说明本申请实施例的量子点发光二极管具有更好的发光效率。It can be seen from Table 1 above that in the quantum dot light-emitting diodes provided in the embodiments of the present application, the electron mobility of the electron transport layer film is significantly higher than that of the corresponding electron transport layer film in the respective comparative examples. Moreover, the external quantum efficiency and lifetime of the quantum dot light-emitting diodes provided by the embodiments of the present application are significantly higher than those of the corresponding quantum dot light-emitting diodes in the comparative examples, indicating that the quantum dot light-emitting diodes of the embodiments of the present application have better luminous efficiency.

以上仅为本申请的可选实施例而已，并不用于限制本申请。对于本领域的技术人员来说，本申请可以有各种更改和变化。凡在本申请的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本申请的权利要求范围之内。The above are only optional embodiments of the application, and are not used to limit the application. For those skilled in the art, this application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included in the scope of the claims of this application.

Claims

一种复合材料，其特征在于，所述复合材料包括n型金属氧化物纳米颗粒和连接在所述n型金属氧化物纳米颗粒表面的如下式I所示的有机分子，所述有机分子上的羧基结合在所述n型金属氧化物纳米颗粒表面；A composite material, characterized in that the composite material comprises n-type metal oxide nanoparticles and organic molecules shown in the following formula I connected on the surface of the n-type metal oxide nanoparticles, and the organic molecules on the The carboxyl group is bound to the surface of the n-type metal oxide nanoparticles;

其中，R ₁为-(CH ₂) _n-，n为大于或等于1的整数。 Wherein, R ₁ is -(CH ₂ ) _n -, and n is an integer greater than or equal to 1.
如权利要求1所述的复合材料，其特征在于，所述有机分子的R ₁中，n＝2～20。 The composite material of claim 1, wherein in R ₁ of the organic molecule, n=2-20.
如权利要求2所述的复合材料，其特征在于，所述有机分子的R ₁中，n＝4～9。 The composite material of claim 2, wherein in R ₁ of the organic molecule, n=4-9.
如权利要求1所述的复合材料，其特征在于，所述有机分子与所述n型金属氧化物纳米颗粒的质量比为(0.1～5)：30。The composite material of claim 1, wherein the mass ratio of the organic molecules to the n-type metal oxide nanoparticles is (0.1-5):30.
如权利要求4所述的复合材料，其特征在于，所述有机分子与所述n型金属氧化物纳米颗粒的质量比为(1～4)：30。The composite material of claim 4, wherein the mass ratio of the organic molecules to the n-type metal oxide nanoparticles is (1˜4):30.
如权利要求1所述的复合材料，其特征在于，所述n型金属氧化物纳米颗粒选自锌的氧化物纳米颗粒、钛的氧化物纳米颗粒、锡的氧化物纳米颗粒、锆的氧化物纳米颗粒和铝掺杂锌的氧化物纳米颗粒中的一种或多种。The composite material of claim 1, wherein the n-type metal oxide nanoparticles are selected from the group consisting of zinc oxide nanoparticles, titanium oxide nanoparticles, tin oxide nanoparticles, and zirconium oxide nanoparticles. One or more of nanoparticles and aluminum-doped zinc oxide nanoparticles.
如权利要求6所述的复合材料，其特征在于，所述n型金属氧化物纳米颗粒选自锌的氧化物纳米颗粒。8. The composite material of claim 6, wherein the n-type metal oxide nanoparticles are selected from zinc oxide nanoparticles.
如权利要求1所述的复合材料，其特征在于，所述复合材料由所述n型金属氧化物纳米颗粒和连接在所述n型金属氧化物纳米颗粒表面的所述有机分子组成。The composite material of claim 1, wherein the composite material is composed of the n-type metal oxide nanoparticles and the organic molecules connected to the surface of the n-type metal oxide nanoparticles.
一种复合材料的制备方法，其特征在于，包括如下步骤：A method for preparing a composite material is characterized in that it comprises the following steps:

提供n型金属氧化物纳米颗粒和如下式II所示的二羧酸单酯有机物；Provide n-type metal oxide nanoparticles and dicarboxylic acid monoester organic compounds as shown in the following formula II;

将所述n型金属氧化物纳米颗粒和二羧酸单酯有机物溶于极性溶剂中，进行加热处理，得到混合溶液；Dissolving the n-type metal oxide nanoparticles and the organic dicarboxylic acid monoester in a polar solvent, and performing heating treatment to obtain a mixed solution;

将所述混合溶液进行固液分离，得到所述复合材料；Subjecting the mixed solution to solid-liquid separation to obtain the composite material;

其中，R ₁为-(CH ₂) _n-，R ₂为-O(CH ₂) _mCH ₃，n为大于或等于1的整数，m为大于或等于0的整数。 Wherein, R ₁ is -(CH ₂ ) _n -, R ₂ is -O(CH ₂ ) _m CH ₃ , n is an integer greater than or equal to 1, and m is an integer greater than or equal to 0.
如权利要求9所述的复合材料的制备方法，其特征在于，所述二羧酸单酯有机物的R ₁中，n＝2～20；和/或， The method for preparing a composite material according to claim 9, wherein in R ₁ of the organic dicarboxylic acid monoester, n=2-20; and/or,

所述二羧酸单酯有机物的R ₂中，m＝2～20。 _{In R 2} of the organic dicarboxylic acid monoester, m=2-20.
如权利要求9所述的复合材料的制备方法，其特征在于，所述二羧酸单酯有机物与所述n型金属氧化物纳米颗粒的质量比为(0.1～5)：30。9. The method for preparing a composite material according to claim 9, wherein the mass ratio of the organic dicarboxylic acid monoester to the n-type metal oxide nanoparticles is (0.1-5):30.
如权利要求9所述的复合材料的制备方法，其特征在于，所述加热处理的温度为60～120℃。The method for preparing a composite material according to claim 9, wherein the temperature of the heating treatment is 60-120°C.
如权利要求9所述的复合材料的制备方法，其特征在于，所述固液分离包括在温度为80～120℃的条件下退火结晶。The method for preparing a composite material according to claim 9, wherein the solid-liquid separation includes annealing and crystallization at a temperature of 80-120°C.
如权利要求9所述的复合材料的制备方法，其特征在于，所述n型金属氧化物纳米颗粒选自锌的氧化物纳米颗粒、钛的氧化物纳米颗粒、锡的氧化物纳米颗粒、锆的氧化物纳米颗粒和铝掺杂锌的氧化物纳米颗粒中的一种或多种。The method for preparing a composite material according to claim 9, wherein the n-type metal oxide nanoparticles are selected from the group consisting of zinc oxide nanoparticles, titanium oxide nanoparticles, tin oxide nanoparticles, and zirconium oxide nanoparticles. One or more of the oxide nanoparticles and aluminum-doped zinc oxide nanoparticles.
一种量子点发光二极管，包括阳极、阴极以及位于所述阳极和所述阴极之间的量子点发光层，所述阴极和所述量子点发光层之间设置有电子传输层，其特征在于，所述电子传输层由权利要求1所述的复合材料组成。A quantum dot light-emitting diode includes an anode, a cathode, and a quantum dot light-emitting layer located between the anode and the cathode, and an electron transport layer is arranged between the cathode and the quantum dot light-emitting layer, and is characterized in that: The electron transport layer is composed of the composite material of claim 1.
如权利要求15所述的量子点发光二极管，其特征在于，所述复合材料中，所述有机分子的R ₁中的n＝2～20。 The quantum dot light emitting diode as claimed in claim 15, wherein said composite material, R ₁ of the organic molecules in n = 2 ~ 20.
如权利要求15所述的量子点发光二极管，其特征在于，所述复合材料中，所述有机分子与所述n型金属氧化物纳米颗粒的质量比为(0.1～5)：30。15. The quantum dot light-emitting diode according to claim 15, wherein in the composite material, the mass ratio of the organic molecules to the n-type metal oxide nanoparticles is (0.1-5):30.
如权利要求15所述的量子点发光二极管，其特征在于，所述复合材料中的所述n型金属氧化物纳米颗粒选自锌的氧化物纳米颗粒、钛的氧化物纳米颗粒、锡的氧化物纳米颗粒、锆的氧化物纳米颗粒和铝掺杂锌的氧化物纳米颗粒中的一种或多种。The quantum dot light-emitting diode of claim 15, wherein the n-type metal oxide nanoparticles in the composite material are selected from the group consisting of zinc oxide nanoparticles, titanium oxide nanoparticles, and tin oxide nanoparticles. One or more of nano-particles, zirconium oxide nanoparticles, and aluminum-doped zinc oxide nanoparticles.
如权利要求18所述的量子点发光二极管，其特征在于，所述复合材料中的所述n型金属氧化物纳米颗粒选自锌的氧化物纳米颗粒。18. The quantum dot light emitting diode of claim 18, wherein the n-type metal oxide nanoparticles in the composite material are selected from zinc oxide nanoparticles.
如权利要求15所述的量子点发光二极管，其特征在于，所述复合材料由所述n型金属氧化物纳米颗粒和连接在所述n型金属氧化物纳米颗粒表面的所述有机分子组成。15. The quantum dot light-emitting diode of claim 15, wherein the composite material is composed of the n-type metal oxide nanoparticles and the organic molecules connected to the surface of the n-type metal oxide nanoparticles.