CN114039000A - Electrode, light emitting device, and electronic apparatus - Google Patents

Electrode, light emitting device, and electronic apparatus Download PDF

Info

Publication number
CN114039000A
CN114039000A CN202011190193.3A CN202011190193A CN114039000A CN 114039000 A CN114039000 A CN 114039000A CN 202011190193 A CN202011190193 A CN 202011190193A CN 114039000 A CN114039000 A CN 114039000A
Authority
CN
China
Prior art keywords
layer
electrode
cationic
emitting device
light emitting
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202011190193.3A
Other languages
Chinese (zh)
Inventor
朱佩
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Guangdong Juhua Printing Display Technology Co Ltd
Original Assignee
Guangdong Juhua Printing Display Technology Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Guangdong Juhua Printing Display Technology Co Ltd filed Critical Guangdong Juhua Printing Display Technology Co Ltd
Priority to CN202011190193.3A priority Critical patent/CN114039000A/en
Publication of CN114039000A publication Critical patent/CN114039000A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
    • H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
    • H10K50/115—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers comprising active inorganic nanostructures, e.g. luminescent quantum dots
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
    • H10K50/14—Carrier transporting layers
    • H10K50/16—Electron transporting layers
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H10K50/80—Constructional details
    • H10K50/805—Electrodes
    • H10K50/81—Anodes
    • H10K50/816—Multilayers, e.g. transparent multilayers

Abstract

The invention relates to an electrode, a light emitting device and an electronic apparatus. The electrode includes: and a conductive layer interface layer bonded to a surface of the conductive layer by means of electrostatic self-assembly, wherein a work function of the electrode is smaller than a work function of the conductive layer. The electrode forms an interface layer on the surface of the conducting layer in a static self-assembly mode, so that the work function of the electrode is reduced, the extraction and injection of electrons are facilitated, the uniformity of the electrode layer can be improved, and the luminous efficiency of a device is improved.

Description

Electrode, light emitting device, and electronic apparatus
Technical Field
The present invention relates to the field of display and lighting technologies, and in particular, to an electrode, a light emitting device, and an electronic apparatus.
Background
In recent years, with the rapid development of display technologies, semiconductor quantum dot materials have attracted extensive attention as quantum dot light emitting diodes (QLEDs), and the quantum dot light emitting diodes have a wide application prospect in the fields of flat panel display, solid state lighting and the like due to the good characteristics of high color purity, high light emitting efficiency, adjustable light emitting color, stable devices and the like.
At present, the QLED screen can be mainly prepared by an ink-jet printing and evaporation method. In particular, the preparation of the inverted QLED device only needs to print a ZnO electron transport layer and a QD light emitting layer on an ITO (tin-doped indium oxide) cathode, and a hole transport layer, a hole injection layer, an anode layer, and the like can be prepared under the evaporation conditions of an OLED (organic light emitting diode), so that the inverted QLED device has great commercial prospect.
However, the ITO thin film has an extremely high work function, resulting in that it is difficult for electrons to be extracted and injected into the electron transport layer when it is used as a cathode. Meanwhile, with the prolonging of the service time, the defects are increased at the interface of the ZnO electron transmission layer and the ITO electrode, so that the electron injection barrier is increased, and the service life of the device is further influenced.
Disclosure of Invention
The present invention has been made in view of the above problems. The present invention aims to provide an electrode, a light-emitting device, and an electronic apparatus capable of avoiding the above problems.
According to a first aspect of the present invention, there is provided an electrode comprising:
a conductive layer;
an interfacial layer bonded to a surface of the conductive layer by means of electrostatic self-assembly,
the work function of the electrode is smaller than that of the conductive layer.
According to the electrode, the interface layer is formed on the surface of the conducting layer in an electrostatic self-assembly mode, the conducting layer is modified, and the work function of the conducting layer is reduced, so that the work function of the electrode is reduced, and electrons are extracted from the electrode and injected into the electron transmission layer; meanwhile, the interface layer is formed in an electrostatic self-assembly mode, so that the number of layers, the thickness and the charged property of the film of the interface layer can be accurately regulated, the coverage rate and the stability of the film are improved, the conductivity and the uniformity of an electrode are ensured, and the luminous efficiency of a device is improved.
In some of these embodiments, the interfacial layer comprises at least one cationic layer and at least one anionic layer,
the cation layer and the anion layer are alternately laminated and have the same number of layers,
the interfacial layer is bonded to a surface of the conductive layer through the cationic layer.
In some embodiments, the material of the conductive layer comprises at least one of ITO (indium tin oxide), IZO (indium zinc oxide), IGZO (indium gallium zinc oxide) and AZO (Al: ZnO, aluminum-doped zinc oxide),
the material of the cationic layer comprises at least one of nanoscale cationic amine-based polymer, nanoscale cationic methyl polymer and nanoscale cationic methacrylic acid,
the material of the anionic layer comprises at least one of nanoscale anionic amine-based polymer, nanoscale anionic methyl polymer and nanoscale anionic methacrylic acid.
In some of these embodiments, the material of the cationic layer comprises at least one of nano-scale quaternary amine chitosan, cationic polyacrylamide and cationic polyhydroxyethyl acrylate,
the material of the anion layer comprises at least one of nano-scale oxygen hydroxymethyl chitosan, anion polyacrylamide and anion polyhydroxyethyl acrylate.
In some of these embodiments, the work function of the electrode is 4.2eV or less.
It is a further object of the present invention to provide a light emitting device comprising a cathode, which is an electrode as described above.
In some of these embodiments, the light emitting device further comprises an electron transport layer in contact with the cathode,
the material of the electron transport layer includes an electron transport material and a cationic surfactant.
In some of these embodiments, the electron transport material comprises at least one of zinc oxide, titanium oxide, and a silicon-containing heterocyclic compound,
the cationic surfactant comprises at least one of aminopropyltriethoxysilane, trialkyl ammonium chloride and dialkyl ethanolamine ester methyl ammonium sulfate.
In some of these embodiments, the light emitting device is an OLED or a QLED.
It is another object of the present invention to provide an electronic device, which includes the above-mentioned electrode; or include the light emitting device described above.
It is noted that the electronic device may be a display device or an illumination device. The display device may be a flat panel display, a television display, an electronic paper, a logic and memory circuit, a flexible display, or the like.
Drawings
Fig. 1 is a schematic structural diagram of a light emitting device according to an embodiment of the present invention.
Detailed Description
In order that the invention may be more fully understood, a more particular description of the invention will now be rendered by reference to specific embodiments thereof that are illustrated in the appended 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.
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.
In order to solve the problem that electrons are difficult to extract and inject into an electron transmission layer when the ITO film is used as a cathode, the surface of the ITO film is modified, so that the work function of the ITO film is reduced, and the uniformity of the ITO film is improved. The invention takes the material with the hydroxyl amino group as the modifying material, and adopts the electrostatic self-assembly method to modify the surface of the ITO film, so that the material with the hydroxyl amino group can accurately regulate and control the number of layers and the property of the film on the nanometer scale to adjust the work function of the ITO film, improve the coverage rate of the film and ensure the conductivity and the uniformity of the film.
An embodiment of the present invention provides an electrode, including: a conductive layer and an interfacial layer; the interface layer is combined on the surface of the conducting layer in an electrostatic self-assembly mode, and the work function of the electrode is smaller than that of the conducting layer.
The electrostatic self-assembly technology is based on electrostatic attraction between opposite charge components, polyelectrolyte with opposite charges is adsorbed on the surface of a substrate with activated charges layer by layer so as to form a multilayer film; meanwhile, the repulsion force of the same charges enables the adsorption quantity of each layer not to be increased endlessly, and the layers reach saturation within a certain time, so that the stable linear growth of the film layer is ensured. The preparation method is simple, the thickness of each film can be accurately controlled at a molecular level, and the stability of the film is good.
The electrode forms an interface layer on the surface of the conducting layer by layer in a static self-assembly mode, and the conducting layer and the interface layer form a dipole through static action, so that the work function of the electrode is reduced, and electrons are extracted from the electrode and injected into the electron transmission layer; meanwhile, the interface layer is formed on the conducting layer in a self-assembling mode by static electricity layer by layer, so that the number of layers, the thickness and the charged property of the film of the interface layer can be accurately regulated and controlled, the coverage rate and the stability of the film are improved, the conductivity and the uniformity of the electrode are ensured, and the luminous efficiency of the device is improved.
In some embodiments, the interfacial layer comprises at least one anionic layer and at least one cationic layer.
In some embodiments, the interfacial layer comprises alternating layers of cations and anions.
In some embodiments, the cationic layers and the anionic layers are alternately stacked and the number of layers is the same.
Further, the interfacial layer is bonded to the surface of the conductive layer through a cationic layer. That is, the interface layer is an anionic layer with respect to the outermost layer of the conductive layer.
Furthermore, the number of the cation layer and the anion layer is 1-4.
Therefore, the number of the layers of the cation layer and the anion layer is controlled to be 1-4 layers by accurate control, the last layer of the self-assembly is the anion layer, the thickness of the interface layer can be controlled to be nano, the surface of the interface layer is negatively charged, and therefore the electron transport layer material with positive charges is easily deposited on the surface of the electrode, the electron transport layer and the electrode can be fully contacted through electrostatic interaction and mutual adsorption, transmission and extraction of electrons are facilitated, and carrier balance of a device is further improved.
In some embodiments, the conductive material of the conductive layer includes at least one of ITO, IZO, IGZO, AZO, and the like.
In some embodiments, the material of the cationic layer comprises at least one of a nanoscale cationic amine-based polymer, a nanoscale cationic methyl polymer, and a nanoscale cationic methacrylic acid;
the material of the anionic layer comprises at least one of nanoscale anionic amine-based polymer, nanoscale anionic methyl polymer and nanoscale anionic methacrylic acid.
By using an organic material containing hydroxyl or/and amino as a material of the interface layer, the work function of the electrode can be modified and adjusted layer by layer on the nanometer size by an electrostatic self-assembly method on the premise of ensuring the conductivity of the electrode, and the uniformity of the surface of the electrode film can be improved.
Further, the material of the cationic layer comprises nanoscale cationic amine-based polymer and cationic methyl polymer, such as at least one of quaternary ammonium chitosan, cationic polyacrylamide, cationic polyhydroxyethyl acrylate, etc.;
the material of the anion layer comprises nanometer-scale anion amine-based polymer and anion methyl polymer, such as at least one of oxygen hydroxyl methyl chitosan, anion polyacrylamide, anion polyhydroxyethyl acrylate and the like.
Thus, the interfacial layer formed by electrostatic self-assembly using the above polymer as a material has a better film-forming property.
In some embodiments, the work function of the electrode is 4.2eV or less.
The electrode modifies the conductive layer by forming an interface layer on the surface of the conductive layer through electrostatic self-assembly, so that the work function of the electrode is smaller than that of the conductive layer, the work function of the electrode is controlled to be lower than 4.2eV, the work function of the electrode is closer to the LUMO level of 3.5eV of an electron transport layer such as a zinc oxide electron transport layer, and the injection of electrons can be promoted.
Another embodiment of the present invention provides a light emitting device, as shown in fig. 1, a light emitting device 100 including: the cathode 20, the electron transport layer 30, the light emitting layer 40, and the anode 70 are stacked on the substrate 10.
It is understood that the light emitting device 100 of the present embodiment is an inverted type structure. In other embodiments, the light emitting device may be a front-mount type structure, and the layer structure is changed accordingly.
The cathode 20 is the above-mentioned electrode, and includes a conductive layer (not shown) and an interface layer (not shown) laminated on the surface of the conductive layer; the interface layer is made of a material which is combined on the surface of the conducting layer in a static layer-by-layer self-assembly mode.
In some embodiments, the thickness of cathode 20 is 50nm to 150 nm.
In some embodiments, the interfacial layer has a thickness of 1nm to 10 nm.
The substrate 10 may be a flexible substrate such as polyimide or polyester, or may be a rigid substrate such as glass or metal.
In some embodiments, the material of the electron transport layer 30 includes an electron transport material and an ionic surfactant, wherein the charge properties of the ionic surfactant are opposite to the charge properties of the interface layer surface.
Thus, the electron transport layer 30 and the interface layer are mutually attracted through electrostatic interaction, so that the electron transport layer 30 is fully contacted with the interface layer of the cathode 20, the electron transport and extraction are more facilitated, and the carrier balance of the device is further improved.
Further, in the electron transport layer 30, an electron transport material and an ionic surfactant are mixed with each other.
In some embodiments, the outermost layer of the interfacial layer relative to the conductive layer is an anionic layer, i.e., the side of the interfacial layer adjacent to the electron transport layer 30 is an anionic layer, and the ionic surfactant in the electron transport layer 30 is a cationic surfactant.
Thus, the last layer of the interface layer self-assembled layer by layer through static electricity is an anion layer, so that the surface of the cathode 20 is negatively charged, and the material for forming the electron transport layer 30 contains a cationic surfactant, which is positively charged, so that the interface of the electron transport layer 30 and the cathode 20 is fully contacted through electrostatic interaction.
In some embodiments, the cationic surfactant is an amine salt type cationic surfactant.
Further, the cationic surfactant is selected from at least one of aminopropyltriethoxysilane, trialkyl ammonium chloride and dialkyl ethanolamine ester methyl ammonium sulfate.
In some embodiments, the electron transport material is an inorganic electron transport material comprising at least one of zinc oxide, titanium oxide, and silicon-containing heterocyclic compounds, among others.
In this embodiment, the conductive layer of the cathode 20 is made of ITO, and the interface layer is made of a polymer containing hydroxylamine groups; the material for forming the electron transport layer 30 includes an electron transport material ZnO and a cationic surfactant. Specifically, the material of the interface layer comprises a cationic amine-based polymer and an anionic amine-based polymer.
Thus, the surface of the ITO conductive layer is modified by adopting an electrostatic layer-by-layer self-assembly method, and the anionic amino polymer are adsorbed on the surface of the ITO conductive layer by layer to form an interface layer, so that the work function of the ITO conductive layer can be reduced, and the work function of the ITO conductive layer is reduced from 4.6eV to about 4.2eV, so that the work function is closer to the LUMO energy level of the zinc oxide electron transport layer of 3.5eV, and the extraction and injection of electrons can be promoted; meanwhile, due to the modification of the self-assembly film layer, the surface roughness of the ITO conductive layer is reduced, and the uniformity of the film layer is improved.
In some embodiments, the thickness of the electron transport layer 30 is 30nm to 150 nm.
In this particular embodiment, the light emitting layer 150 of the light emitting device 100 is a quantum dot light emitting layer, i.e. the light emitting device is a QLED device.
Further, the material of the quantum dot light emitting layer may be selected from group II-VI compound semiconductors including, but not limited to, core-shell quantum dot materials such as CdS, CdSe, CdS/ZnS, CdSe/ZnS, ZnCdS/ZnS, CdSe/CdS/ZnS, or graded shell based quantum dot materials; and may also be selected from group III-V or group IV-VI compound semiconductors including, but not limited to, InP, InAs, InP, InAsP, GaAs, PbS/ZnS, PbSe/ZnS; and may be selected from group I-III-VI semiconductor nanocrystals.
In other embodiments, the light emitting layer of the light emitting device may be an organic light emitting layer, i.e. the light emitting device 100 is an OLED device.
Further, the material of the organic light emitting layerThe material is selected from Ir (piq)3、Ir(ppy)3、C545T、Ir(ppy)2(acac), Firpic, and DCJTB.
In some embodiments, light-emitting device 100 further includes a hole transport layer 50 disposed between light-emitting layer 40 and anode 70.
Further, the thickness of the hole transport layer 50 is 30nm to 40 nm.
Further, the material of the hole transport layer 60 may be, but is not limited to, poly-TPD (poly [ bis (4-phenyl) (4-butylphenyl) amine)]) Organic transport materials such as TFB (poly (9, 9-dioctylfluorene-co-n- (4-butylphenyl) diphenylamine)), NiO (nickel oxide), MoO3Inorganic transport materials such as (molybdenum trioxide) and composites thereof.
In an embodiment, light emitting device 100 further includes a hole injection layer 60 disposed between hole transport layer 50 and anode 70.
Further, the thickness of the hole injection layer 60 is 30nm to 40 nm.
Further, the material of the hole injection layer 70 is selected from PEDOT (poly (3, 4-ethylenedioxythiophene)), F4-TCNQ (tetrafluorotetracyanoquinodimethane), MoO3、V2O5(vanadium pentoxide) and WO3(tungsten trioxide) and the like.
In some embodiments, the material of the anode 70 may be Ag, Al, or Mg, or a composite metal formed of these metals, such as Mg — Ag alloy, or the like.
In some embodiments, the thickness of the anode 70 is 20nm to 100 nm.
In some embodiments, the light emitting device 100 further includes an encapsulation layer 80 disposed over the anode 70.
An embodiment of the present invention provides a method for manufacturing a light emitting device, including the steps of:
providing a substrate, and forming a cathode on the substrate;
sequentially laminating an electron transport layer, a light emitting layer and an anode on the cathode;
wherein, the cathode comprises a conductive layer and an interface layer laminated and combined on the surface of the conductive layer; the work function of the material of the interface layer is smaller than that of the material of the conductive layer, and the material of the interface layer is combined on the surface of the conductive layer in a static layer-by-layer self-assembly mode.
Specifically, the cathode and each functional layer of the light-emitting device are formed by ink-jet printing or evaporation.
In some embodiments, the materials forming the interfacial layer include cationic organic materials and anionic organic materials.
In some embodiments, the cationic organic material is a cationic amine-based polymer and the anionic organic material is an anionic amine-based polymer.
In some embodiments, the material forming the electron transport layer comprises an electron transport material and an ionic surfactant having a charge property opposite to a charge property of the interface layer surface;
and forming an electron transmission layer by adopting a static layer-by-layer self-assembly method.
In some embodiments, the ionic surfactant is a cationic surfactant.
In one embodiment, the cathode and electron transport layer are prepared as follows:
depositing a cationic amino polymer (such as quaternary ammonium chitosan) on a conductive layer (such as a zinc oxide film) by adopting an ink-jet printing method to form a cationic amino polymer film, then depositing an anionic amino polymer (such as oxymethylol chitosan) on the cationic amino polymer film by adopting an ink-jet printing method, forming an anionic amino polymer film by adopting an electrostatic self-assembly method, repeating the operation, alternately depositing for 2-4 times, and obtaining an interface layer by taking the last layer as the anionic amino polymer film;
dispersing electron transport material (such as zinc oxide) with cationic surfactant (such as 3-aminopropyl triethoxysilane) to obtain electron transport layer material ink, depositing the electron transport layer material ink onto cathode by ink jet printing method, and forming electron transport layer by electrostatic self-assembly method.
Therefore, the multilayer organic film is formed on the conductive layer by the electrostatic self-assembly method, the conductive layer can be well covered, the defects and the roughness of the conductive layer are reduced, the work function difference between the electrode and the electron transmission layer is reduced, the electron transmission barrier is reduced, and the electron extraction and injection of the device are promoted. Meanwhile, the ink of the electron transport layer material with cations is deposited on the interface layer, so that the ink forms regularly arranged electron transport material particles through electrostatic self-assembly in the drying process, the electron transport layer is fully contacted with the cathode interface, the injection and the transmission of electrons are further facilitated, the carrier balance is improved, and the luminous efficiency and the service life of the device are further improved.
Still another embodiment of the present invention also provides an electronic device including the above electrode or light emitting device.
In some embodiments, the electronic device may be a display device or a lighting device. The display device includes, but is not limited to, a flat panel display, a television display, an electronic paper, a logic and memory circuit, a flexible display, and the like.
The following are specific examples
Example 1
An electrode comprises an ITO conductive layer and an interface layer, wherein the interface layer is combined on the surface of the ITO conductive layer in an electrostatic self-assembly mode. The ITO conductive layer had a thickness of 15nm, the interface layer had a thickness of about 2nm, the interface layer included a cationic layer and an anionic layer alternately stacked, each of the cationic layer and the anionic layer had 3 layers, and finally formed was an anionic layer.
Preparing an electrode:
providing a substrate, cleaning and drying the substrate, and preparing an ITO conductive film with the thickness of 15nm on the substrate as an ITO conductive layer.
Respectively adopting an ink-jet printing mode to alternately deposit a chitosan cation derivative quaternary amine chitosan solution (with the concentration of 1mg/mL) and an anion derivative oxygen hydroxymethyl chitosan solution (with the concentration of 1mg/mL) on the surface of the ITO conducting layer by layer through electrostatic self-assembly to form an interface layer. Wherein, quaternary amine chitosan solution and oxygen hydroxymethyl chitosan solution are alternately deposited for 6 times, and oxygen hydroxymethyl chitosan solution is finally deposited.
Example 2
An electrode comprises an ITO conductive layer and an interface layer, wherein the interface layer is combined on the surface of the ITO conductive layer in an electrostatic self-assembly mode. The ITO conductive layer had a thickness of 20nm, the interface layer had a thickness of about 1.5nm, the interface layer included a cationic layer and an anionic layer alternately stacked, each of the cationic layer and the anionic layer had 2 layers, and finally formed was an anionic layer.
Preparing an electrode:
providing a substrate, cleaning and drying the substrate, and preparing an ITO conductive film with the thickness of 20nm on the substrate as an ITO conductive layer.
Respectively adopting an ink-jet printing mode to alternately deposit a chitosan cation derivative quaternary amine chitosan solution (1mg/mL) and an anion derivative oxygen hydroxymethyl chitosan solution (1mg/mL) on the surface of the ITO conducting layer by layer through electrostatic self-assembly to form an interface layer. Wherein, quaternary amine chitosan solution and oxygen hydroxymethyl chitosan solution are alternately deposited for 4 times, and oxygen hydroxymethyl chitosan solution is finally deposited.
Example 3
An electrode comprises an ITO conductive layer and an interface layer, wherein the interface layer is combined on the surface of the ITO conductive layer in an electrostatic self-assembly mode.
Preparing an electrode:
providing a substrate, cleaning and drying the substrate, and preparing an ITO conductive film with the thickness of 15nm on the substrate as an ITO conductive layer.
Respectively adopting an ink-jet printing mode to alternately deposit a cationic polyacrylamide solution (1mg/mL) and an anionic polyacrylamide solution (1mg/mL) on the surface of the ITO conducting layer by layer through electrostatic self-assembly to form an interface layer with the thickness of 2 nm. Wherein, the cation polyacrylamide solution and the anion polyacrylamide solution are alternately deposited for 8 times, and the anion polyacrylamide solution is finally deposited.
Example 4
A QLED top emission device comprising a cathode, an electron transport layer, a quantum dot light emitting layer, a hole transport layer, a hole injection layer and an anode, which are stacked and disposed on a substrate, wherein the cathode is the electrode of embodiment 1.
The structure of the QLED light-emitting device is as follows: ITO (15 nm)/zinc oxide (50 nm)/quantum dot light emitting layer (20nm)/poly-TPD (30nm)/PEDOT (20 nm)/silver (20 nm). In the structure representation method, each functional layer such as zinc oxide (50nm) represents that the electron transmission layer is a zinc oxide thin film layer with the thickness of 50 nm.
Preparing a QLED top light-emitting device:
after a cathode is prepared according to the method of example 1, a zinc oxide ink (with a concentration of 50mg/mL) dispersed with cationic surfactant aminopropyltriethoxysilane is deposited on the surface of the cathode by means of inkjet printing, and then a quantum dot light-emitting layer, a hole transport layer and an anode with corresponding thicknesses are sequentially deposited by means of inkjet printing or evaporation.
Example 5
A QLED bottom emission device comprising a cathode, an electron transport layer, a quantum dot light emitting layer, a hole transport layer, a hole injection layer and an anode, which are stacked and disposed on a substrate, wherein the cathode is the electrode of embodiment 2.
The structure of the QLED light-emitting device is as follows: ITO (20 nm)/zinc oxide (30 nm)/quantum dot light emitting layer (20nm)/poly-TPD (30nm)/PEDOT (20 nm)/silver (70 nm).
Preparing a QLED bottom light-emitting device:
after a cathode is prepared according to the method of example 2, a zinc oxide ink (with a concentration of 50mg/mL) in which cationic surfactant aminopropyltriethoxysilane is dispersed is deposited on the surface of the cathode by means of inkjet printing, and then a quantum dot light-emitting layer, a hole transport layer and an anode with corresponding thicknesses are sequentially deposited by means of inkjet printing or evaporation.
Example 6
A QLED top emission device comprising a cathode, an electron transport layer, a quantum dot light emitting layer, a hole transport layer, a hole injection layer and an anode, which are stacked and disposed on a substrate, wherein the cathode is the electrode of embodiment 3.
The structure of the QLED light-emitting device is as follows: ITO (15 nm)/zinc oxide (50 nm)/quantum dot light emitting layer (20nm)/poly-TPD (30nm)/PEDOT (20 nm)/silver (20 nm).
Preparing a QLED top light-emitting device:
after a cathode is prepared according to the method of example 3, a zinc oxide ink (with a concentration of 50mg/mL) in which cationic surfactant aminopropyltriethoxysilane is dispersed is deposited on the surface of the cathode by means of inkjet printing, and then a quantum dot light-emitting layer, a hole transport layer and an anode with corresponding thicknesses are sequentially deposited by means of inkjet printing or evaporation.
Example 7
An electronic device includes a substrate, an inverted QLED top-emitting device bonded on the substrate, and an encapsulation film for encapsulating the QLED top-emitting device. Here, the structure of the QLED top emission device is the same as that of embodiment 4.
The structure of the electronic device is as follows: ITO (15nm) Ag (140nm) + ITO (15 nm)/zinc oxide (50 nm)/quantum dot light emitting layer (20nm)/poly-TPD (30nm)/PEDOT (20 nm)/silver (20 nm)/encapsulation layer (100 nm).
Example 8
An electronic device comprises a substrate, an inverted QLED bottom light-emitting device combined on the substrate and a packaging film used for packaging the QLED bottom light-emitting device. Wherein, the structure of the QLED bottom emission device is the same as that of the QLED bottom emission device of embodiment 5.
The structure of the electronic device is as follows: ITO (20 nm)/zinc oxide (30 nm)/quantum dot light emitting layer (20nm)/poly-TPD (30nm)/PEDOT (20 nm)/silver (70 nm)/encapsulating layer (100 nm).
Example 9
An electronic device, comprising: the QLED light-emitting device comprises a substrate, an inverted QLED top light-emitting device combined on the substrate and an encapsulation film used for encapsulating the QLED top light-emitting device. Among them, the structure of the QLED top emission device is the same as that of the QLED top emission device of embodiment 6.
The structure of the electronic device is as follows: ITO (15nm) Ag (140nm) + ITO (15 nm)/zinc oxide (50 nm)/quantum dot light emitting layer (20nm)/poly-TPD (30nm)/PEDOT (20 nm)/silver (20 nm)/encapsulation layer (100 nm).
Comparative example 1
The electrode of comparative example 1 was a common ITO electrode having no ITO thin film layer after 15nm, which was different from the electrode of example 1 in that the surface of the ITO thin film layer had no interface layer.
Comparative example 2
Comparative example 2 is a standard device, i.e. the ITO electrode surface is not modified.
Specifically, the electronic device of comparative example 2 includes a substrate, an inverted QLED bottom emission device bonded to the substrate, and an encapsulation film for encapsulating the QLED bottom emission device.
The structure of the QLED bottom light-emitting device is as follows: the ITO (20 nm)/zinc oxide (30 nm)/quantum dot light emitting layer (20nm)/poly-TPD (30nm)/PEDOT (20 nm)/silver (70 nm)/packaging layer (100nm), wherein the surface of the ITO electrode is free of an interface layer, and the zinc oxide electron transport layer is free of a surfactant.
Performance detection
The performance of the electrodes of examples 1 to 3, the light emitting devices of examples 4 to 6, the electrode of comparative example 1, and the QLED device of comparative example 2 was tested, and the results are shown in table 1 below.
TABLE 1
Work function of electrode (eV) Electrode Rq EQE(RQD)
Comparative example 1 4.6 2.4 5.3％
Comparative example 2 / / 5.3％
Example 1 4.2 1.8 /
Example 2 4.2 1.8 /
Example 3 4.18 1.3 /
Example 4 / / 7.7％
Example 5 / / 6.4％
Example 6 / / 8.5％
Note: the electrode Rq is the root-mean-square roughness of the surface of the film, the electrode Rq is obtained by scanning with an atomic force microscope, the lower the Rq is, the flatter the surface of the film is, the fewer defects of the film are, and current carriers can be transmitted more effectively;
EQE (rqd) is the external quantum efficiency of red quantum dots, which refers to the efficiency of excited photons after carrier recombination, and is used to characterize the efficiency of quantum dot devices, with higher EQE indicating more balanced carrier injection and higher efficiency; and testing by using an efficiency brightness test system.
As can be seen from table 1 above, the electrodes of embodiments 1 to 3 of the present application are subjected to interface modification, and compared with the conventional electrode of comparative example 1, the work function is reduced, and the surface is flatter, and the luminous efficiency of the QLED devices of embodiments 4 to 6 is significantly improved compared with the conventional QLED device of comparative example 2, which indicates that after the ITO electrode of the QLED device is modified, electrons are more easily injected, and carriers are more easily combined in the luminous region, so that the luminous efficiency of the device is increased.
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 (10)

1. An electrode, comprising:
a conductive layer;
an interfacial layer bonded to a surface of the conductive layer by means of electrostatic self-assembly,
the work function of the electrode is smaller than that of the conductive layer.
2. The electrode of claim 1, wherein the interfacial layer comprises at least one cationic layer and at least one anionic layer,
the cation layer and the anion layer are alternately laminated and have the same number of layers,
the interfacial layer is bonded to a surface of the conductive layer through the cationic layer.
3. The electrode according to claim 2, wherein a material of the conductive layer comprises at least one of ITO, IZO, IGZO, and AZO,
the material of the cationic layer comprises at least one of nanoscale cationic amine-based polymer, nanoscale cationic methyl polymer and nanoscale cationic methacrylic acid,
the material of the anionic layer comprises at least one of nanoscale anionic amine-based polymer, nanoscale anionic methyl polymer and nanoscale anionic methacrylic acid.
4. The electrode of claim 3, wherein the material of the cationic layer comprises at least one of nano-scale quaternary amine chitosan, cationic polyacrylamide, and cationic polyhydroxyethyl acrylate,
the material of the anion layer comprises at least one of nano-scale oxygen hydroxymethyl chitosan, anion polyacrylamide and anion polyhydroxyethyl acrylate.
5. The electrode according to any one of claims 1 to 4, wherein the work function of the electrode is 4.2eV or less.
6. A light-emitting device comprising a cathode, wherein the cathode is an electrode according to any one of claims 1 to 5.
7. The light-emitting device according to claim 6, further comprising an electron transport layer in contact with the cathode,
the material of the electron transport layer includes an electron transport material and a cationic surfactant.
8. The light-emitting device according to claim 7, wherein the electron-transporting material comprises at least one of zinc oxide, titanium oxide, and a silicon-containing heterocyclic compound,
the cationic surfactant comprises at least one of aminopropyltriethoxysilane, trialkyl ammonium chloride and dialkyl ethanolamine ester methyl ammonium sulfate.
9. A light emitting device according to any one of claims 6 to 8, wherein the light emitting device is an OLED or a QLED.
10. An electronic device comprising the electrode according to any one of claims 1 to 4 and/or the light-emitting device according to any one of claims 6 to 9.
CN202011190193.3A 2020-10-30 2020-10-30 Electrode, light emitting device, and electronic apparatus Pending CN114039000A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202011190193.3A CN114039000A (en) 2020-10-30 2020-10-30 Electrode, light emitting device, and electronic apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011190193.3A CN114039000A (en) 2020-10-30 2020-10-30 Electrode, light emitting device, and electronic apparatus

Publications (1)

Publication Number Publication Date
CN114039000A true CN114039000A (en) 2022-02-11

Family

ID=80134124

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011190193.3A Pending CN114039000A (en) 2020-10-30 2020-10-30 Electrode, light emitting device, and electronic apparatus

Country Status (1)

Country Link
CN (1) CN114039000A (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104821374A (en) * 2015-03-12 2015-08-05 华南理工大学 Preparation method of organic optoelectronic device cathode interface layer based on conjugated polyelectrolyte and application thereof
US20160181541A1 (en) * 2014-12-23 2016-06-23 Gwangju Institute Of Science And Technology P-doped conjugated small molecular electrolyte and organic electronic devices using the same
CN108807720A (en) * 2017-04-26 2018-11-13 Tcl集团股份有限公司 Functionalization cathode, QLED and preparation method, illuminating module and display device
CN110739408A (en) * 2018-07-18 2020-01-31 Tcl集团股份有限公司 Quantum dot light-emitting diode and preparation method thereof
CN111223999A (en) * 2018-11-26 2020-06-02 Tcl集团股份有限公司 Quantum dot light-emitting diode and preparation method thereof

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20160181541A1 (en) * 2014-12-23 2016-06-23 Gwangju Institute Of Science And Technology P-doped conjugated small molecular electrolyte and organic electronic devices using the same
CN104821374A (en) * 2015-03-12 2015-08-05 华南理工大学 Preparation method of organic optoelectronic device cathode interface layer based on conjugated polyelectrolyte and application thereof
CN108807720A (en) * 2017-04-26 2018-11-13 Tcl集团股份有限公司 Functionalization cathode, QLED and preparation method, illuminating module and display device
CN110739408A (en) * 2018-07-18 2020-01-31 Tcl集团股份有限公司 Quantum dot light-emitting diode and preparation method thereof
CN111223999A (en) * 2018-11-26 2020-06-02 Tcl集团股份有限公司 Quantum dot light-emitting diode and preparation method thereof

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
QUN CHEN, ET AL.: "Finely Tailored Performance of Inverted Organic Photovoltaics through Layer-by-Layer Interfacial Engineering", 《ACS APPLIED MATERIALS & INTERFACES》 *

Similar Documents

Publication Publication Date Title
US11515446B2 (en) Element, electronic device, and method for producing element
CN101405888B (en) Nanostructured electroluminescent device and display
CN110718637B (en) Quantum dot light-emitting diode and preparation method thereof
CN111384256B (en) Quantum dot light-emitting diode and preparation method thereof
KR20100082556A (en) Electroluminescent device including quantum dot multilayer thin film
CN109216566B (en) Composite light emitting layer, QLED device and preparation method thereof
CN109216567B (en) Composite light emitting layer, QLED device and preparation method thereof
CN110970579A (en) Zinc oxide nanocrystalline electron transport layer, preparation method thereof and electronic device
CN108695413B (en) A kind of electroluminescent device and preparation method thereof
CN110649167A (en) Quantum dot light-emitting diode and preparation method thereof
CN114039000A (en) Electrode, light emitting device, and electronic apparatus
CN111244298A (en) Light-emitting device and display
CN111223999A (en) Quantum dot light-emitting diode and preparation method thereof
CN114039002B (en) Electron transport ink, electron transport film, electroluminescent diode, and display device
CN112349853B (en) Electroluminescent device, preparation method thereof and display device
KR20140083190A (en) Organic electroluminescent device and fabracation method by using graphene oxide
CN109244252B (en) QLED device and preparation method thereof
CN114342102A (en) Element and electronic device
CN115568241B (en) Light-emitting device, preparation method thereof and display device
WO2024078562A1 (en) Film and preparation method therefor, and photoelectric device
CN115734639A (en) Film, preparation method of film, photoelectric device and display panel
CN115915809A (en) Film, light-emitting device and display panel
CN116209331A (en) Processing method of photoelectric device and photoelectric device
CN114068296A (en) ZnS composite material, preparation method thereof, ZnS film and light-emitting device
CN113130787A (en) Composite material, quantum dot light-emitting diode and preparation method thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
RJ01 Rejection of invention patent application after publication
RJ01 Rejection of invention patent application after publication

Application publication date: 20220211