Disclosure of Invention
The embodiment of the application aims to provide a quantum dot light-emitting device and a preparation method thereof. Which aims to improve the lifetime of quantum dot light emitting devices.
The first aspect of the present application provides a method for manufacturing a quantum dot light emitting device, including:
mixing a polyether compound and metal oxide nanoparticles to obtain a mixed solution, and forming a film on the quantum dot light-emitting layer by using the mixed solution; the polyether compound is an insulating compound.
The polyether compound can increase the distance between metal oxide nano-particles, and can prevent dehydration condensation between functional groups on the surfaces of the metal oxide nano-particles to improve the transmission performance of electrons; the polyether compound can reduce the dehydration rate among functional groups, and meanwhile, oxygen atoms in the ether polymer can also form hydrogen bonds with hydroxyl (-OH) of the functional group on the surface of the metal oxide nano-particle, so that the electron mobility is integrally reduced due to the electron-withdrawing capacity of the hydrogen bonds; the mixed liquid is formed into a film to form an electron transmission layer which is arranged on the quantum dot light emitting layer to improve the transmission performance of electrons.
Accordingly, the improvement of the electron transport property is advantageous to the improvement of the lifetime of the quantum dot light emitting device.
In some embodiments of the first aspect of the present application, the polyether compound has a molecular weight of 1000 to 100000.
Optionally, the molecular weight of the polyether compound is 8000 to 30000.
In some embodiments of the first aspect of the present disclosure, the polyether compound has a functionality of 30 to 120.
In some embodiments of the first aspect of the present application, the polyether compound is selected from at least one of polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polybutylene glycol diglycidyl ether, polypentylene glycol diglycidyl ether, and polyhexamethylene glycol diglycidyl ether.
In some embodiments of the first aspect of the present disclosure, the concentration of the metal oxide nanoparticles in the mixed liquor is 16 to 51mg/ml.
In some embodiments of the first aspect of the present application, mixing the polyether compound with the metal oxide nanoparticles further comprises:
firstly, the polyether compound is mixed with a nonpolar solvent.
In some embodiments of the first aspect of the present application, the non-polar solvent comprises at least one of methanol, ethanol, acetonitrile, butanol, and isopropanol.
In some embodiments of the first aspect of the present application, the metal oxide nanoparticles comprise ZnO, niO, W 2 O 3 、Mo 2 O 3 、TiO 2 、SnO、ZrO 2 And Ta 2 O 3 At least one of (1).
In some embodiments of the first aspect of the present disclosure, the mixed solution is formed into a film at 30-50 ℃.
The second aspect of the present application provides a quantum dot light-emitting device, which is manufactured by the above method for manufacturing a quantum dot light-emitting device.
The embodiment of the application improves the electron transmission performance of the electron transmission layer of the quantum dot light-emitting device, so that the service life of the quantum dot light-emitting device is prolonged.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.
The quantum dot light emitting device and the method of manufacturing the same according to the embodiments of the present application will be described in detail below.
A method for preparing a quantum dot light-emitting device mainly comprises the following steps:
mixing polyether compounds and metal oxide nanoparticles to obtain a mixed solution, and forming a film on the quantum dot light-emitting layer by using the mixed solution; the polyether compound is an insulating compound.
In the application, a film is formed on the quantum dot light-emitting layer, and the material of the film comprises polyether compound and metal oxide nano-particles, wherein the polyether compound is an insulating compound.
The surface of the metal oxide nanoparticles has a plurality of functional groups, such as hydroxyl, carboxyl, amino, sulfydryl and the like. Hydrogen bonds are formed between the functional groups to prevent further electron transport. In addition, under the influence of external factors such as heat, electricity, light and the like, dehydration condensation between partial functional groups to form-O-bonds can occur to enhance the electron transport performance. Meanwhile, oxygen atoms in the ether polymer and hydroxyl (-OH) which is a functional group on the surface of the metal oxide nano-particle form hydrogen bonds, and the electron mobility is integrally reduced due to the electron withdrawing capacity of the hydrogen bonds.
In the embodiment of the application, the polyether compound can increase the distance between the metal oxide nanoparticles, and prevent the formation of hydrogen bonds between functional groups on the surfaces of the metal oxide nanoparticles so as to improve the electron transport performance; the polyether compound can reduce the dehydration rate among functional groups and improve the transmission performance of electrons. Accordingly, the improvement of the electron transport property is advantageous for the improvement of the lifetime of the quantum dot light emitting device.
In the examples of the present application, the molecular weight of the polyether compound is 1000 to 100000. Illustratively, the polyether compound has a molecular weight of 1000 to 2000; or 2000-3500, 4500-6500, 7000-8000, 9000-15000, 15000-3000, 90000-100000, etc.
The polyether compound with a relatively high molecular weight is beneficial to blocking hydrogen bonds formed between functional groups on the surface of the metal oxide nanoparticles, but the polyether compound with a relatively high molecular weight can cause non-uniformity of a film obtained after film formation, so that, in some embodiments of the present application, the molecular weight of the polyether compound is 1000 to 100000.
Further, in some embodiments herein, the functionality of the polyether compound is from 30 to 120.
Illustratively, the polyether compound is at least one selected from the group consisting of polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, polypentylene glycol diglycidyl ether, and polyhexamethylene glycol diglycidyl ether.
In this embodiment, the polyether compound is polyethylene glycol diglycidyl ether.
The molecular structural formula of the polyethylene glycol diglycidyl ether is as follows:
in other embodiments of the present application, the polyether compound may be other polyethylene glycol diglycidyl ethers.
In embodiments of the present application, the metal oxide nanoparticles comprise ZnO, niO, W 2 O 3 、Mo 2 O 3 、TiO 2 、SnO、ZrO 2 And Ta 2 O 3 At least one of (1). For example, in the present embodiment, the metal oxide nanoparticles are ZnO or ZrO 2 。
In the examples of the present application, the concentration of the metal oxide nanoparticles in the mixed solution is 16 to 51mg/ml. In other words, the mixed solution contains 16 to 51mg of the metal oxide nanoparticles per 1ml of the mixed solution. For example, the concentration of the metal oxide nanoparticles in the mixed solution is 16mg/ml, 18mg/ml, 23mg/ml, 30mg/ml, 34mg/ml, 40mg/ml, 43mg/ml, 50mg/ml, 51mg/ml.
In some embodiments of the present application, the mixed solution further comprises a nonpolar solvent.
Further, the method for mixing the polyether compound with the metal oxide nanoparticles comprises the following steps: firstly, the polyether compound is mixed with a nonpolar solvent.
The polyether compound is mixed with the nonpolar solvent and then mixed with the metal oxide nanoparticles, so that the metal oxide nanoparticles and the polyether compound can be fully dispersed. The metal oxide nano-particles after being fully dispersed can reduce the number of hydrogen bonds formed by surface groups of the metal oxide nano-particles.
Illustratively, the nonpolar solvent may include at least one of methanol, ethanol, acetonitrile, butanol, and isopropanol.
The volume ratio of the nonpolar solvent to the polyether compound can be 1; for example, 1.
In other embodiments of the present application, the non-polar solvent may be other solvents, or in other embodiments, the non-polar solvent may not be included in the mixed solution.
In the embodiments of the present application, the film formation method may be spin coating or coating.
In this embodiment, a method for manufacturing a quantum dot light-emitting device includes:
mixing 3-10ml of polyethylene glycol diglycidyl ether with 10ml of ethanol, then adding 100mg of metal oxide nano-particles, and stirring for 20-40 minutes to uniformly disperse the metal oxide nano-particles in the solution to obtain a mixed solution.
And forming a film on the mixed solution on the quantum dot light-emitting layer by adopting a spin coating or coating mode, and baking the film at 30-60 ℃ until the film is dried.
The preparation method of the quantum dot light-emitting device provided by the embodiment of the application has the main advantages that:
the polyether compound increases the distance between metal oxide nano particles, and prevents hydrogen bonds formed between functional groups, thereby improving the transmission performance of electrons; the polyether compound can reduce the dehydration rate among functional groups and improve the transmission performance of electrons. Accordingly, the improvement of the electron transport property is advantageous to the improvement of the lifetime of the quantum dot light emitting device.
The embodiment of the application also provides a quantum dot light-emitting device which is mainly prepared by the preparation method of the quantum dot light-emitting device.
The electron transmission performance of the electron transmission layer of the quantum dot light-emitting device is improved, so that the service life of the quantum dot light-emitting device is prolonged.
The features and properties of the present application are described in further detail below with reference to examples.
Example 1
The embodiment provides a quantum dot light-emitting device which is mainly prepared by the following steps:
sequentially preparing a hole transport layer, a quantum dot light emitting layer, an electron transport layer and a cathode on a clean ITO glass substrate; the preparation steps of the electron transport layer are as follows:
3ml of polyethylene glycol diglycidyl ether is mixed with 10ml of ethanol, wherein the molecular weight of the polyethylene glycol diglycidyl ether is about 1000. Then 100mgZnO nanoparticles are added, and the mixture is stirred for 20 minutes to uniformly disperse the metal oxide nanoparticles in the solution to obtain a mixed solution. And forming a film on the quantum dot light-emitting layer by adopting a spin coating mode, and baking the film at 30 ℃ until the film is dried.
Example 2
The embodiment provides a quantum dot light-emitting device which is mainly prepared by the following steps:
sequentially preparing a hole transport layer, a quantum dot light emitting layer, an electron transport layer and a cathode on a clean ITO glass substrate; the preparation steps of the electron transport layer are as follows:
5ml of polyethylene glycol diglycidyl ether is mixed with 10ml of ethanol, wherein the molecular weight of the polyethylene glycol diglycidyl ether is about 10000. Then 100mgZnO nanoparticles are added, and stirring is carried out for 40 minutes to ensure that the metal oxide nanoparticles are uniformly dispersed in the solution to obtain a mixed solution. And forming a film on the quantum dot light-emitting layer by adopting a coating mode, and baking the film at 40 ℃ until the film is dried.
Example 3
The embodiment provides a quantum dot light-emitting device which is mainly prepared by the following steps:
sequentially preparing a hole transport layer, a quantum dot light emitting layer, an electron transport layer and a cathode on a clean ITO glass substrate; the preparation steps of the electron transport layer are as follows:
mixing 7ml of polyethylene glycol diglycidyl ether with 10ml of ethanol, wherein the molecular weight of the polyethylene glycol diglycidyl ether is about 10000. Then 100mg TiO was added 2 And stirring the nano particles for 50 minutes to uniformly disperse the metal oxide nano particles in the solution to obtain a mixed solution. And forming a film on the quantum dot light-emitting layer by adopting a coating mode, and baking the film at 50 ℃ until the film is dried.
Example 4
The embodiment provides a quantum dot light-emitting device which is mainly prepared by the following steps:
preparing a hole transport layer, a quantum dot light emitting layer, an electron transport layer and a cathode on a clean ITO glass substrate in sequence; the preparation steps of the electron transport layer are as follows:
mixing 7ml of polyethylene glycol diglycidyl ether with 10ml of ethanol, wherein the molecular weight of the polyethylene glycol diglycidyl ether is about 10000. Then 100mg TiO was added 2 Stirring the nanoparticles for 50 minutes to obtain metal oxide nanoparticlesThe particles are uniformly dispersed in the solution to obtain a mixed solution. And forming a film on the mixed solution on the quantum dot light-emitting layer by adopting a spin coating or coating mode, and baking the film at 70 ℃ until the film is dried.
Comparative example 1
The present comparative example provides a quantum dot light-emitting device, which is mainly produced by the steps of:
sequentially preparing a hole transport layer, a quantum dot light emitting layer, an electron transport layer and a cathode on a clean ITO glass substrate; the preparation steps of the electron transport layer are as follows:
taking 13ml of ethanol, adding 100mgZnO nanoparticles, and stirring for 20 minutes to uniformly disperse the metal oxide nanoparticles in the solution to obtain a mixed solution. And forming a film on the mixed solution on the quantum dot light-emitting layer by adopting a spin coating mode, and baking the film at 30 ℃ until the film is dried.
Test examples
The quantum dot light-emitting devices provided in examples 1 to 4 and comparative example 1 were tested for luminous efficiency and service life; the lifetime T95 means that the luminance of the device is 5000cd/m 2 Time at 95% decay at current density. The test results are shown in Table 1.
TABLE 1 test results of examples 1 to 4 and comparative example 1
Examples
|
Luminous efficiency
|
Life T95
|
Example 1
|
12
|
150
|
Example 2
|
13
|
160
|
Example 3
|
11
|
180
|
Example 4
|
12.5
|
168
|
Comparative example 1
|
10
|
100 |
As can be seen from table 1, the efficiency and the service life of the quantum dot light emitting devices provided in examples 1 to 4 of the present application are significantly higher than those of comparative example 1, and it can be seen that the electron transport layer obtained by the preparation method of the quantum dot light emitting device provided in the present application can improve the electron transport performance. Further improving the efficiency and the service life of the quantum dot light-emitting device.
The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.