CN114039004A

CN114039004A - Light emitting device and method of manufacturing the same

Info

Publication number: CN114039004A
Application number: CN202011631277.6A
Authority: CN
Inventors: 朱佩
Original assignee: Guangdong Juhua Printing Display Technology Co Ltd
Current assignee: Guangdong Juhua Printing Display Technology Co Ltd
Priority date: 2020-12-31
Filing date: 2020-12-31
Publication date: 2022-02-11
Anticipated expiration: 2040-12-31
Also published as: CN114039004B

Abstract

The invention relates to a light emitting device and a manufacturing method thereof. The light-emitting device comprises a first electrode, a hole transport layer, an interface layer, a quantum dot light-emitting layer and a second electrode, wherein the hole transport layer is arranged on the first electrode, the interface layer is arranged on the hole transport layer and comprises a carbon material, the quantum dot light-emitting layer is arranged on the interface layer, and the second electrode is arranged on the quantum dot light-emitting layer. The existence of interface layer can avoid the solvent in the quantum dot solution to dissolve hole transport layer material to the good electric conductivity of interface layer has reduced the contact resistance between hole transport layer and the quantum dot luminescent layer, promotes the injection and the transmission of hole, makes hole and electron can be better at the recombination of quantum dot luminescent layer, improves luminescent device's efficiency. In addition, the interface layer can prevent excessive electrons from accumulating between the hole transport layer and the quantum dot light-emitting layer, inhibit the damage of partial leakage electrons to the hole transport layer, improve the stability of the hole transport layer and prolong the service life of the device.

Description

Light emitting device and method of manufacturing the same

Technical Field

The invention relates to the technical field of display, in particular to a light-emitting device and a manufacturing method thereof.

Background

In recent years, with the rapid development of display technology, quantum dot light emitting diodes (QLEDs) having semiconductor quantum dot materials as light emitting layers have received much attention. The semiconductor quantum dot material has the advantages of high color purity, high luminous efficiency, adjustable luminous color, stable device and the like, so that the quantum dot light-emitting diode has wide application prospect in the fields of flat panel display, solid state lighting and the like.

By solution processesIn the process of preparing QLED device, hole transport layer material such as TFB (1,2,4, 5-tetra (trifluoromethyl) benzene), PVK (polyvinyl carbazole), styrene, NiO (nickel oxide), MoO₃The (molybdenum trioxide) and the like are easily dissolved by a solvent of the quantum dot light-emitting layer, and the contact resistance between the hole transport layer and the quantum dot light-emitting layer is relatively large, so that a carrier is easily compounded at the interface of the hole transport layer and the quantum dot light-emitting layer, and further the efficiency and the service life of the QLED device are reduced.

Disclosure of Invention

Based on this, there is a need for a light emitting device and a method for fabricating the same to improve the efficiency and lifetime of QLED devices.

An object of the present invention is to provide a light emitting device, which is configured as follows:

a light emitting device, comprising:

a first electrode;

a hole transport layer disposed on the first electrode;

an interfacial layer disposed on the hole transport layer, the interfacial layer comprising a carbon material;

a quantum dot light emitting layer disposed on the interface layer;

and the second electrode is arranged on the quantum dot light-emitting layer.

In one embodiment, the interfacial layer is comprised of the carbon material.

In one embodiment, the surface of the hole transport layer is modified with a first functional group, and the surface of the interface layer facing the hole transport layer is modified with a second functional group, wherein the first functional group and the second functional group are connected through electrostatic interaction.

In one embodiment, the first functional group is a hydroxyl group and the second functional group is a carboxyl group and/or an amine group.

In one embodiment, a surface of the interface layer facing the quantum dot light-emitting layer is modified with a third functional group, a surface of the quantum dot light-emitting layer is modified with a fourth functional group, and the third functional group and the fourth functional group are connected through electrostatic interaction.

In one embodiment, the third functional group is a hydroxyl group, and the fourth functional group is a carboxyl group and/or an amine group.

In one embodiment, the carbon material is selected from one or more of carbon nanotubes, carbon quantum dots, and carbon fibers.

In one embodiment, the interface layer has a thickness of 2nm to 10 nm.

Another object of the present invention is to provide a method for manufacturing a light emitting device, which comprises the following steps:

a method for manufacturing a light emitting device comprises the following steps:

manufacturing a hole transport layer on the first electrode;

forming an interface layer on the hole transport layer, the interface layer comprising a carbon material;

manufacturing a quantum dot light-emitting layer on the interface layer;

and manufacturing a second electrode on the quantum dot light-emitting layer.

In one embodiment, the step of forming an interfacial layer on the hole transport layer comprises:

modifying a first functional group on the surface of the hole transport layer;

and depositing an interface layer on the hole transport layer, wherein a second functional group is modified on the surface of one side, facing the hole transport layer, of the interface layer, and the first functional group can be connected with the second functional group through electrostatic interaction.

In one embodiment, the method for modifying the surface of the hole transport layer with the first functional group includes soaking the surface of the hole transport layer with a first alkali solution;

the second functional group is a carboxyl group and/or an amine group.

In one embodiment, the first base solution is selected from one or more of a potassium hydroxide solution, a sodium hydroxide solution, and a calcium hydroxide solution.

In one embodiment, the concentration of the first alkali solution is 2mol/l to 5 mol/l.

In one embodiment, the step of fabricating a quantum dot light emitting layer on the interface layer comprises:

modifying a third functional group on the surface of the interface layer;

and depositing a quantum dot material with a surface modified with a fourth functional group on the interface layer, so that the third functional group can be connected with the fourth functional group through electrostatic interaction.

In one embodiment, the method for modifying the surface of the interface layer with the third functional group comprises soaking the surface of the interface layer with a second alkali solution;

the quantum dot material modified with the fourth functional group on the surface is a quantum dot material with a surface ligand containing carboxyl and/or amino.

In one embodiment, the second base solution is selected from one or more of a potassium hydroxide solution, a sodium hydroxide solution, and a calcium hydroxide solution.

In one embodiment, the concentration of the second alkali solution is 2mol/l to 5 mol/l.

Compared with the prior scheme, the light-emitting device and the manufacturing method thereof have the following beneficial effects:

according to the light-emitting device and the manufacturing method thereof, the interface layer is arranged between the hole transport layer and the quantum dot light-emitting layer and comprises the carbon material, when the light-emitting device is manufactured by a solution method, the problem that a solvent in a quantum dot solution dissolves a hole transport layer material is avoided, the contact resistance between the hole transport layer and the quantum dot light-emitting layer is reduced due to good conductivity of the interface layer, the injection and the transmission of holes are promoted, the holes and electrons can be better compounded in the quantum dot light-emitting layer, the carrier balance of the device is improved, and the efficiency of the light-emitting device is improved. In addition, due to the existence of the interface layer, the accumulation of excessive electrons between the hole transport layer and the quantum dot light emitting layer can be blocked, the damage of partial leakage electrons to the hole transport layer is inhibited, the stability of the hole transport layer is improved, and the service life of the device is further prolonged.

Drawings

Fig. 1 is a schematic structural view of a light-emitting device according to an embodiment.

Fig. 2 is a schematic view of the adsorption between the hole transport layer and the interface layer by cations and anions.

Description of reference numerals:

100. a light emitting device; 110. a first electrode; 120. a hole transport layer; 130. an interfacial layer; 140. a quantum dot light emitting layer; 150. a second electrode; 160. a substrate; 170. a hole injection layer; 180. an electron transport layer.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1, a light emitting device 100 according to an embodiment of the invention includes a first electrode 110, a hole transport layer 120, an interface layer 130, a quantum dot light emitting layer 140, and a second electrode 150.

The hole transport layer 120 is disposed on the first electrode 110. An interface layer 130 is disposed on the hole transport layer 120, the interface layer 130 comprising a carbon material. The quantum dot light emitting layer 140 is disposed on the interface layer 130. The second electrode 150 is disposed on the quantum dot light emitting layer 140.

According to the light-emitting device 100, the interface layer 130 is arranged between the hole transport layer 120 and the quantum dot light-emitting layer 140, the interface layer 130 contains a carbon material, when the light-emitting device 100 is manufactured by a solution method, a solvent in a quantum dot solution is prevented from dissolving a material of the hole transport layer 120, the contact resistance between the hole transport layer 120 and the quantum dot light-emitting layer 140 is reduced due to the good conductivity of the interface layer 130, the injection and transmission of holes are promoted, the holes and electrons can be better compounded in the quantum dot light-emitting layer 140, the carrier balance of the device is improved, and the efficiency of the light-emitting device 100 is improved. In addition, due to the existence of the interface layer, the accumulation of excessive electrons between the hole transport layer 120 and the quantum dot light emitting layer 140 can be blocked, the damage of partial leakage electrons to the hole transport layer 120 is inhibited, the stability of the hole transport layer is improved, and the service life of the device is further prolonged.

In one example, the interface layer 130 has a thickness of 2nm to 10 nm. Too thin an interfacial layer 130 may not be able to form a film and does not play a role, while too thick a film may directly affect hole transport and injection. Further, in one example, the interface layer 130 has a thickness of 4nm to 8 nm. In some specific examples, the interface layer 130 has a thickness of 3nm, 5nm, 7nm, 9nm, and the like.

In one example, the interface layer 130 is composed of a carbon material.

In one example, the carbon material is selected from one or more of carbon nanotubes, carbon quantum dots, and carbon fibers.

In one example, the carbon material is a carbon quantum dot. Because the carbon quantum dot material is a one-dimensional nano material, the defect of the hole transport material film can be better filled, the surface roughness of the hole transport layer 120 is reduced, and the uniformity of a subsequently formed film layer is improved.

In one example, the surface of the hole transport layer 120 is modified with a first functional group, and the surface of the interface layer 130 facing the hole transport layer 120 is modified with a second functional group, wherein the first functional group and the second functional group are connected by electrostatic interaction.

In the light-emitting device 100 of the above example, the carbon materials of the hole transport layer 120 and the interface layer 130 are connected by the first functional group and the second functional group through electrostatic interaction, so that the hole transport layer 120 and the interface layer 130 are more tightly combined, the conductivity is improved, the contact resistance between the two layers is reduced, and the injection and transport of holes are promoted. Meanwhile, due to the modification of the self-assembly film, the surface roughness of the hole transport layer 120 is reduced, and the uniformity of the film is improved.

Note that both the first functional group and the second functional group are not limited to a single kind of functional group, and both the first functional group and the second functional group may be a plurality of kinds of functional groups.

In one example, the first functional group is an anionic group and the second functional group is a cationic group. In the present example, the first functional group and the second functional group are specifically linked by an ionic bond.

In one example, the first functional group is a hydroxyl group and the second functional group is a carboxyl group and/or an amine group. As shown in fig. 2, the carbon material is anchored on the hole transport layer 120 by adsorption of cations and anions.

In one example, a surface of the interface layer 130 facing the quantum dot light emitting layer 140 is modified with a third functional group, a surface of the quantum dot light emitting layer 140 is modified with a fourth functional group, and the third functional group and the fourth functional group are connected through electrostatic interaction.

In the light emitting device 100 of the above example, the interface layer 130 and the quantum dot light emitting layer 140 are connected through the third functional group and the fourth functional group by electrostatic interaction, so that the interface layer 130 and the quantum dot light emitting layer 140 are combined more tightly, the contact resistance between the two layers is reduced, and the injection and transmission of holes are promoted.

It should be noted that the third functional group and the fourth functional group are not limited to a single kind of functional group, and the third functional group and the fourth functional group may be a plurality of kinds of functional groups.

In one example, the third functional group is an anionic group and the fourth functional group is a cationic group. In the present example, the third functional group and the fourth functional group are specifically linked by an ionic bond.

In one example, the third functional group is a hydroxyl group and the fourth functional group is a carboxyl group and/or an amine group.

Due to the modification of the self-assembled film, the surface roughness of the interface layer 130 is reduced, and the film uniformity is improved.

Carboxyl or amido functional groups are modified on the surface of the quantum dot material, so that mutual electrostatic repulsion between quantum dot particles is realized, the quantum dot particle agglomeration is inhibited, the quantum dot light-emitting layer can be uniformly arranged and covered on the interface layer, the hole transmission layer and the quantum dot light-emitting layer have better interface contact, the better interface contact can promote the injection of holes, the combination of the holes and electrons in the quantum dot light-emitting layer is further promoted, and the efficiency and the service life of the device are improved.

In one example, the material of the hole transport layer 120 is selected from TFB (1,2,4, 5-tetrakis (trifluoromethyl) benzene), PVK (polyvinylcarbazole), styrene, NiO (nickel oxide), MoO₃(molybdenum trioxide) and poly-TPD.

In one example, the quantum dot material in the quantum dot light emitting layer 140 can be, but is not limited to, a core-shell quantum dot such as CdSe/ZnS, CdS/ZnSe, CdZnS/ZnSe, or a graded shell based quantum dot material.

It will be appreciated that the light emitting device 100 further comprises a substrate 160, as shown in fig. 1, the substrate 160 serving as a carrier for the TFT driver array and the functional layers thereon. The substrate 160 may be a flexible substrate such as polyimide or the like, or a rigid substrate such as glass or the like.

As shown in fig. 1, in one example, the light emitting device 100 further includes a hole injection layer 170 disposed between the first electrode 110 and the hole transport layer 120.

As shown in fig. 1, in one example, the light emitting device 100 further includes an electron transport layer 180 disposed between the quantum dot light emitting layer 140 and the second electrode 150. The electron transport layer 180 may be, but is not limited to, zinc oxide.

Further, the invention also provides a manufacturing method of the light-emitting device, which comprises the following steps:

fabricating a hole transport layer 120 on the first electrode 110;

forming an interface layer 130 on the hole transport layer 120, the interface layer 130 comprising a carbon material;

manufacturing a quantum dot light emitting layer 140 on the interface layer 130;

a second electrode 150 is fabricated on the quantum dot light emitting layer 140.

In one example, the step of forming the interface layer 130 on the hole transport layer 120 includes:

modifying the surface of the hole transport layer 120 with a first functional group;

and depositing an interface layer 130 on the hole transport layer 120, wherein the surface of one side, facing the hole transport layer 120, of the interface layer 130 is modified with a second functional group, and the first functional group and the second functional group can be connected through electrostatic interaction.

In one example, the method of modifying the surface of the hole transport layer 120 with the first functional group includes soaking the surface of the hole transport layer 120 with a first alkali solution. Further, the step of soaking the surface of the hole transport layer 120 with the first alkali solution is to print a layer of the first alkali solution on the hole transport layer 120, and soak the layer for 0.5 to 2 hours, so that the surface of the material of the hole transport layer 120 uniformly adsorbs hydroxyl groups, and then dry the material.

In one example, the first base solution is selected from one or more of a potassium hydroxide solution, a sodium hydroxide solution, and a calcium hydroxide solution.

In one example, the concentration of the first alkali solution is 2mol/l to 5 mol/l.

In one example, the second functional group is a carboxyl group and/or an amine group.

In one example, the step of fabricating the quantum dot light emitting layer 140 on the interface layer 130 includes:

modifying a third functional group on the surface of the interface layer 130;

and depositing a quantum dot material with a surface modified with a fourth functional group on the interface layer 130, wherein the third functional group can be connected with the fourth functional group through electrostatic interaction.

In one example, the method for modifying the surface of the interface layer 130 with the third functional group includes soaking the surface of the interface layer 130 with a second alkaline solution. Further, the carbon material surface is adopted to adsorb hydroxyl uniformly and is dried.

In one example, the second base solution is selected from one or more of a potassium hydroxide solution, a sodium hydroxide solution, and a calcium hydroxide solution.

In one example, the concentration of the second base solution is 2mol/l to 5 mol/l.

In one example, the quantum dot material surface-modified with the fourth functional group is a quantum dot material having a surface ligand containing a carboxyl group and/or an amine group. The method can adopt a quantum dot material with a surface ligand of an oil-soluble ligand (such as oleic acid), and adds substances such as glycolic acid or mercaptoethylamine and the like to perform ligand exchange, so as to obtain the water-soluble quantum dot material with a surface group of carboxyl or amine.

In one example, the interface layer 130 is formed on the hole transport layer 120 by printing a carbon material solution on the hole transport layer 120 and drying the printed solution to form a film. In this example, the thickness of the interface layer 130 may be controlled by the concentration of the carbon material and the number of ink print drops.

In one example, the carbon material solution has a concentration of 3mg/ml to 8 mg/ml.

The following examples are provided to illustrate the present invention, but the present invention is not limited to the following examples, and it should be understood that the appended claims outline the scope of the present invention and those skilled in the art who are guided by the inventive concept will appreciate that certain changes made to the embodiments of the present invention will be covered by the spirit and scope of the claims of the present invention.

Example 1

The embodiment provides a light emitting device and a method for manufacturing the same.

The structure of the light emitting device is as follows:

ITO/Ag/ITO/PEDOT/TFB/carbon quantum dot interface layer/red quantum dot light emitting layer/zinc oxide/silver/packaging layer.

The manufacturing method of the light-emitting device comprises the following steps:

(1) a substrate with an ITO (15nm)/Ag (140nm)/ITO (15nm) electrode is adopted, and the substrate is cleaned and dried according to a standard method.

(2) Depositing PEDOT on the substrate by adopting an ink-jet printing method, and drying to obtain a hole injection layer with the thickness of 20 nm;

(3) and (3) depositing TFB on the hole injection layer obtained in the step (2) by adopting an ink-jet printing method, and drying to obtain a hole transport layer with the thickness of 30 nm.

(4) And (3) printing a layer of KOH solution on the hole transport layer obtained in the step (3) by adopting an ink-jet printing method, and soaking the hole transport layer in the KOH solution for 1h to enable the surface of the TFB film to uniformly adsorb hydroxyl ions.

(5) And (3) printing 6 drops of carbon quantum dot solution rich in carboxyl ions with the concentration of 3mg/ml on the surface of the TFB film adsorbing the hydroxyl in the step (4) by adopting an ink-jet printing method, so that the carbon quantum dots are anchored on the surface of the TFB film through the carboxyl ions, and after the reaction is finished, heating to 100 ℃ for 30min to volatilize solvent molecules, thereby forming an interface layer with the thickness of 5 nm.

(6) And (3) printing a layer of KOH solution on the interface layer obtained in the step (5) by adopting an ink-jet printing method, and soaking the interface layer in the KOH solution for 1h to enable the carbon quantum dots to adsorb hydroxyl ions.

(7) And (3) printing 8 drops of quantum dot luminescent material adopting carboxyl provided by mercaptoacetic acid ligand exchange on the carbon quantum dot absorbing hydroxyl in the step (6) by adopting an ink-jet printing method, and anchoring the carboxyl provided by mercaptoacetic acid on the carbon quantum dot rich in hydroxyl to obtain the quantum dot luminescent layer with the thickness of 20 nm.

(8) And subsequently, sequentially depositing zinc oxide on the quantum dot light emitting layer to obtain an electron transmission layer with the thickness of 20nm, depositing a silver layer on the electron transmission layer to obtain an electrode layer with the thickness of 20nm, and depositing on the electrode layer to form a packaging layer with the thickness of 100 nm.

Example 2

The structure of the light emitting device is as follows:

ITO/PEDOT/TFB/carbon nano tube interface layer/blue quantum dot light emitting layer/zinc oxide/silver/packaging layer.

(1) and (3) adopting a substrate with an ITO (50nm) electrode, cleaning the substrate according to a standard method, and drying.

(5) And (3) printing 6 drops of carbon nanotube solution rich in amino radical ions with the concentration of 3mg/ml on the surface of the TFB film adsorbing the hydroxyl in the step (4) by adopting an ink-jet printing method, so that the carbon nanotubes are anchored on the surface of the TFB film through the amino radical ions, and after the reaction is finished, heating to 100 ℃ for 30min to volatilize solvent molecules, thereby forming an interface layer with the thickness of 10 nm.

(6) And (3) printing a layer of KOH solution on the interface layer obtained in the step (5) by adopting an ink-jet printing method, and soaking the interface layer in the KOH solution for 1h to enable the carbon nano tubes to adsorb hydroxyl ions.

(7) And (3) printing 8 drops of blue quantum dot luminescent material provided with amino by 3-mercapto-1-propylamine on the carbon quantum dot adsorbing hydroxyl in the step (6) by adopting an ink-jet printing method, and anchoring the amino provided by the 3-mercapto-1-propylamine on the carbon nano tube rich in hydroxyl to obtain the blue quantum dot luminescent layer with the thickness of 20 nm.

(8) And subsequently, sequentially depositing zinc oxide on the blue quantum dot light-emitting layer to obtain an electron transmission layer with the thickness of 20nm, depositing a silver layer on the electron transmission layer to obtain an electrode layer with the thickness of 100nm, and depositing on the electrode layer to form a packaging layer with the thickness of 100 nm.

Example 3

The structure of the light emitting device is as follows:

ITO/Ag/ITO/PEDOT/TFB/carbon fiber interface layer/red quantum dot light emitting layer/zinc oxide/silver/packaging layer.

(1) and cleaning and drying the ITO/Ag/ITO substrate by adopting an ITO (15nm)/Ag (140nm)/ITO (15nm) electrode according to a standard method.

(5) And (3) printing 6 drops of carbon fiber solution rich in carboxyl ions with the concentration of 3mg/ml on the surface of the TFB film adsorbing the hydroxyl in the step (4) by adopting an ink-jet printing method, so that the carbon fibers are anchored on the surface of the TFB film through the carboxyl ions, and after the reaction is finished, heating to 100 ℃ for 30min to volatilize solvent molecules, thereby forming an interface layer with the thickness of 5 nm.

(6) And (3) printing a layer of KOH solution on the interface layer obtained in the step (5) by adopting an ink-jet printing method, and soaking the interface layer in the KOH solution for 1h to enable the carbon fiber to absorb hydroxyl ions.

(7) And (3) printing 8 drops of quantum dot luminescent material adopting carboxyl provided by mercaptoacetic acid ligand exchange on the carbon fiber adsorbing hydroxyl in the step (6) by adopting an ink-jet printing method, and anchoring the carboxyl provided by mercaptoacetic acid on the carbon fiber rich in hydroxyl to obtain the quantum dot luminescent layer with the thickness of 20 nm.

Example 4

The structure of the light emitting device is as follows:

(4) Printing 6 drops of carbon fiber solution with the concentration of 3mg/ml on the surface of the TFB film by adopting an ink-jet printing method, so that the carbon fiber directly covers the surface of the TFB film, and heating to 100 ℃ for 30min after the reaction is finished so as to volatilize solvent molecules and form an interface layer with the thickness of 5 nm.

(5) And (4) printing 8 drops of quantum dot luminescent material on the carbon fiber in the step (4) by adopting an ink-jet printing method to obtain a quantum dot luminescent layer with the thickness of 20 nm.

(6) And subsequently, sequentially depositing zinc oxide on the quantum dot light emitting layer to obtain an electron transmission layer with the thickness of 20nm, depositing a silver layer on the electron transmission layer to obtain an electrode layer with the thickness of 20nm, and depositing on the electrode layer to form a packaging layer with the thickness of 100 nm.

Example 5

The structure of the light emitting device is as follows:

(4) Printing 2 drops of carbon fiber solution with the concentration of 3mg/ml on the surface of the TFB film by adopting an ink-jet printing method, so that the carbon fiber directly covers the surface of the TFB film, and heating to 100 ℃ for 30min after the reaction is finished so as to volatilize solvent molecules and form an interface layer with the thickness of 2 nm.

Comparative example 1

The structure of the light emitting device provided in comparative example 1 is:

ITO/PEDOT/TFB/red quantum dot light emitting layer/zinc oxide/silver/encapsulation layer.

This structure differs from example 1 in that no interface layer is present.

(7) And (4) depositing a quantum dot luminescent material on the hole transport layer obtained in the step (3) by adopting an ink-jet printing method to obtain a quantum dot luminescent layer with the thickness of 20 nm.

The results of testing the light-emitting devices manufactured in examples 4 to 7 and comparative example 1 are shown in table 1.

As can be seen from the results in table 1, compared with comparative example 1, the light-emitting devices manufactured in examples 1 to 4 have lower surface roughness of the interface layer, and the device efficiency and lifetime are significantly improved. It should be noted that the relatively low efficiency of example 2 is mainly due to the fact that in example 2, which is a blue quantum dot device, the charge needs more energy to excite a photon, and the efficiency and lifetime are relatively low.

TABLE 1

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A light emitting device, comprising:

a first electrode;

a hole transport layer disposed on the first electrode;

a quantum dot light emitting layer disposed on the interface layer;

and the second electrode is arranged on the quantum dot light-emitting layer.

2. The light-emitting device according to claim 1, wherein a surface of the hole transport layer is modified with a first functional group, a surface of the interface layer on a side facing the hole transport layer is modified with a second functional group, and the first functional group and the second functional group are connected by electrostatic interaction.

3. A light emitting device according to claim 2, wherein the first functional group is a hydroxyl group, and the second functional group is a carboxyl group and/or an amine group.

4. The light-emitting device according to any one of claims 1 to 3, wherein a surface of the interface layer facing the quantum dot light-emitting layer is modified with a third functional group, a surface of the quantum dot light-emitting layer is modified with a fourth functional group, and the third functional group and the fourth functional group are connected through electrostatic interaction.

5. The light-emitting device according to claim 4, wherein the third functional group is a hydroxyl group, and the fourth functional group is a carboxyl group and/or an amine group.

6. The light-emitting device according to any one of claims 1 to 3 and 5, wherein the carbon material is selected from one or more of a carbon nanotube, a carbon quantum dot, and a carbon fiber.

7. The light-emitting device according to any one of claims 1 to 3 and 5, wherein the interface layer has a thickness of 2nm to 10 nm.

8. A manufacturing method of a light-emitting device is characterized by comprising the following steps:

manufacturing a hole transport layer on the first electrode;

manufacturing a quantum dot light-emitting layer on the interface layer;

and manufacturing a second electrode on the quantum dot light-emitting layer.

9. The method of claim 8, wherein the step of forming an interfacial layer on the hole transport layer comprises:

modifying a first functional group on the surface of the hole transport layer;

10. The method according to claim 9, wherein the step of modifying the surface of the hole transport layer with the first functional group comprises immersing the surface of the hole transport layer with a first alkali solution;

the second functional group is a carboxyl group and/or an amine group.

11. The method of claim 10, wherein the first base solution is selected from one or more of a potassium hydroxide solution, a sodium hydroxide solution, and a calcium hydroxide solution.

12. The method of any of claims 8 to 11, wherein the step of forming a quantum dot light emitting layer on the interface layer comprises:

modifying a third functional group on the surface of the interface layer;

and depositing a quantum dot material with a surface modified with a fourth functional group on the interface layer, wherein the third functional group can be connected with the fourth functional group through electrostatic interaction.

13. The method of manufacturing of claim 12,

the method for modifying the surface of the interface layer with the third functional group comprises the steps of soaking the surface of the interface layer with a first alkali solution;