KR102301616B1 - Light-emitting diode comprising two-dimensional metal carbide transparent electrode and preparation method thereof - Google Patents

Abstract

The present invention relates to a light emitting device including a two-dimensional transition metal carbide transparent electrode and a method for manufacturing the same. According to the present invention, a light emitting device comprising a transparent MXene electrode and a neutralized conductive polymer composition hole injection layer (n-GraHIL) uses an MXene material, which has a lower production cost than the existing ITO, with high efficiency equivalent to that of the existing ITO-based light emitting device. In the case of depositing the MXene transparent electrode on a PET substrate, it can be implemented as a flexible light emitting device, so it is possible to manufacture a flexible light emitting device with high efficiency at low cost compared to the production cost of a conventional ITO-based light emitting device.

Description

Light-emitting device including two-dimensional transition metal carbide transparent electrode and manufacturing method thereof

The present invention relates to a light emitting device including a two-dimensional transition metal carbide transparent electrode and a method for manufacturing the same.

MXene is a 2D nanomaterial developed by Professor Yury Gogotsi of Drexel University, and refers to a two-dimensional transition metal carbide or nitride. This is a nanomaterial composed of a double element of a transition metal atom such as titanium (Ti) and a carbon (C) atom, and has a two-dimensional plate-like structure having a thickness of several nm (nano) and a length of several μm (micrometer) in shape. Eggplant is a 2D nanomaterial, can be solution processed, has excellent electrical conductivity, is light, and has advantages of low cost, so it has been actively studied in recent years.

The MXene has been actively researched and developed in the fields of ion batteries, sensors, and catalysts, and is also being studied as a transparent electrode material, but related research is still scarce in the field of optoelectronics.

1. WO 2019/055784 A1

A first object of the present invention is to provide a light emitting device using a two-dimensional transition metal carbide as a transparent electrode.

A second object of the present invention is to provide a method of manufacturing a light emitting device including the two-dimensional transition metal carbide transparent electrode.

In order to achieve the first object, the present invention provides a substrate; a first electrode positioned on the substrate; a hole injection layer positioned on the first electrode; a light emitting layer positioned on the hole injection layer; and a second electrode positioned on the light emitting layer, wherein the first electrode is an electrode including an MXene material represented by the following Chemical Formula 1, and the hole injection layer is a conductive polymer with a fluorine-based material of Chemical Formula 2 and a basic material To provide a light emitting device comprising a conductive polymer composition having a work function of 5.6 eV or more in a thin film and neutralized to a pH of 4.0 to 10.0 in a dispersion or solution state by adding a .

[Formula 1]

M _n+1 X _n T _x

(In Formula 1,

M is a transition metal,

X is C or N;

T _x is a -OH, -O or -F end group located on the surface,

n is an integer from 1 to 3.)

[Formula 2]

(In Formula 2,

0 < m ≤ 10,000,000, 0 ≤ n < 10,000,000, 0 ≤ a ≤ 20, 0 ≤ b ≤ 20;

A, B, A' and B' are each independently selected from the group consisting of C, Si, Ge, Sn, and Pb;

R ₁ , R ₂ , R ₃ , R ₄ , R ₁ ', R ₂ ', R ₃ ' and R ₄ ' are each independently hydrogen, halogen, nitro group, substituted or unsubstituted amino group, cyano group, substituted or unsubstituted C ₁ -C ₃₀ alkyl group, substituted or unsubstituted C ₁ -C ₃₀ heteroalkyl group, substituted or unsubstituted C ₁ -C ₃₀ alkoxy group, substituted or unsubstituted C ₁ -C ₃₀ heteroalkoxy group, a substituted or unsubstituted C ₆ -C ₃₀ aryl group, a substituted or unsubstituted C ₆ -C aryl group, a substituted or unsubstituted aryloxy-substituted C ₆ -C _30, substituted or unsubstituted C _{2 30} - C ₃₀ heteroaryl group, substituted or unsubstituted C ₂ -C ₃₀ heteroarylalkyl group, substituted or unsubstituted C ₂ -C ₃₀ heteroaryloxy group, substituted or unsubstituted C ₅ -C ₂₀ cyclo Alkyl group, substituted or unsubstituted C ₂ -C ₃₀ heterocycloalkyl group, substituted or unsubstituted C ₁ -C ₃₀ alkylester group, substituted or unsubstituted C ₁ -C ₃₀ heteroalkyl ester group, substituted or unsubstituted selected from the group consisting of a C ₆ -C ₃₀ aryl ester group and a substituted or unsubstituted C ₂ -C ₃₀ heteroaryl ester group, provided that at least one of _{R 1} , R ₂ , R ₃ , and R _{4 .} The above is an ionic group or contains an ionic group;

X and X' are each independently a simple bond, O, S, a substituted or unsubstituted C ₁ -C ₃₀ alkylene group, a substituted or unsubstituted C ₁ -C ₃₀ heteroalkylene group, a substituted or unsubstituted C ₆ - C ₃₀ arylene group, substituted or unsubstituted C ₆ -C ₃₀ arylalkylene group, substituted or unsubstituted C ₂ -C ₃₀ heteroarylene group, substituted or unsubstituted C ₂ -C ₃₀ heteroarylalkylene group , a substituted or unsubstituted C ₅ -C ₂₀ cycloalkylene group, a substituted or unsubstituted C ₅ -C ₃₀ heterocycloalkylene group, a substituted or unsubstituted C ₆ -C ₃₀ aryl ester group, and a substituted or It is selected from the group consisting of an unsubstituted C ₂ -C _{30 heteroaryl ester group,}

However, when n is 0, _{at least one of R 1} , R ₂ , R ₃ , and R ₄ is a hydrophobic functional group including a halogen element or a hydrophobic functional group.)

The MXene material is Ti ₂ C, Ti ₂ N, Mo ₂ C,V ₂ C, Nb ₂ C, Ti ₃ C ₂ , Zr ₃ C ₂ , Ti ₄ N ₃ , V ₄ C ₃ , Nb ₄ C ₃ , Ta ₄ C ₃ and derivatives thereof.

The first electrode has a transmittance of 50 to 95%, and a sheet resistance of 10 to 300 ohm/sq (or 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120) by controlling the thickness of the MXene thin film. , 130, 140, 150, 200, 250, 300 ohm/sq)).

The MXene material may be one in which -OH groups and -O groups on the surface are removed through heat treatment on the surface and the density of -F groups is increased.

The conductive polymer is a copolymer including two or more different repeating units selected from among polythiophene, polyaniline, polypyrrole, polystyrene, polyethylenedioxythiophene, polyacetylene, polyphenylene, polyphenylvinylene and polycarbazole, and derivatives thereof. or a mixture of two or more thereof.

The basic material is naphthylamine (2-Naphtylamine), arylaniline (n-Allylaniline), aminobiphenyl (4-Aminobiphenyl), toluidine (o-Toluidine), aniline (Aniline), quinoline (Quinoline), dimethyl aniline It is selected from the group consisting of (N,N,-Diethyl aniline) and pyridine (Pyridine), and may be an amine compound or a pyridine compound having a pKa of 4-6.

The conductive polymer composition may include a PEDOT:PSS polymer, a perfluorinated ionomer (PFI), and aniline.

The conductive polymer composition comprises 100 parts by weight of a conductive polymer, 100 to 300 parts by weight of a fluorine-based material (or a value of one of 100, 120, 150, 170, 200, 250, or 300 parts by weight), 0.5 to 5 parts by weight of a basic material (or 0.5, 0.7, 1, 1.5, 2,3,4,5 parts by weight).

The light emitting device may be selected from the group consisting of a light emitting diode, a light-emitting transistor, a laser light emitting device, and a polarized light emitting device.

The active layer used for light emission may include, but is not limited to, an organic light emitting material, an organic-inorganic hybrid halide perovskite light source, an inorganic halide perovskite light source, a Cd-based quantum dot, an In-based quantum dot, and the like.

The driving method of the light emitting device may be a DC driving method or a pulse driving method. Preferably, the light emitting device of the direct current driving method of 20 V or less, more preferably 15 V or less, and more preferably 10 V or less may be included. If an insulator is placed in the lower part, upper part, or both of the lower and upper parts of the light emitting body and light is emitted in an alternating current driving method, a high voltage (>50 V) is required, so that a low power light emitting device cannot be driven.

The light emitting device may be a flexible light emitting device using a flexible substrate.

In addition, in order to achieve the second object of the present invention, the present invention comprises the steps of forming a first electrode including an MXene material represented by the following Chemical Formula 1 on a substrate (S10); forming a hole injection layer on the first electrode with a conductive polymer composition including a conductive polymer, a fluorine-based material represented by Chemical Formula 2, and a basic material (S20); forming a light emitting layer on the hole injection layer (S30); and forming a second electrode on the light emitting layer (S40).

[Formula 1]

M _{n+ 1} X _n T _x

(In Formula 1,

M is a transition metal,

X is C or N;

T _x is a -OH, -O or -F end group located on the surface,

n is an integer from 1 to 3.)

[Formula 2]

(In Formula 2,

0 < m ≤ 10,000,000, 0 ≤ n < 10,000,000, 0 ≤ a ≤ 20, 0 ≤ b ≤ 20;

A, B, A' and B' are each independently selected from the group consisting of C, Si, Ge, Sn, and Pb;

R ₁ , R ₂ , R ₃ , R ₄ , R ₁ ', R ₂ ', R ₃ ' and R ₄ ' are each independently hydrogen, halogen, nitro group, substituted or unsubstituted amino group, cyano group, substituted or unsubstituted C ₁ -C ₃₀ alkyl group, substituted or unsubstituted C ₁ -C ₃₀ heteroalkyl group, substituted or unsubstituted C ₁ -C ₃₀ alkoxy group, substituted or unsubstituted C ₁ -C ₃₀ heteroalkoxy group, a substituted or unsubstituted C ₆ -C ₃₀ aryl group, a substituted or unsubstituted C ₆ -C aryl group, a substituted or unsubstituted aryloxy-substituted C ₆ -C _30, substituted or unsubstituted C _{2 30} - C ₃₀ heteroaryl group, substituted or unsubstituted C ₂ -C ₃₀ heteroarylalkyl group, substituted or unsubstituted C ₂ -C ₃₀ heteroaryloxy group, substituted or unsubstituted C ₅ -C ₂₀ cyclo Alkyl group, substituted or unsubstituted C ₂ -C ₃₀ heterocycloalkyl group, substituted or unsubstituted C ₁ -C ₃₀ alkylester group, substituted or unsubstituted C ₁ -C ₃₀ heteroalkyl ester group, substituted or unsubstituted selected from the group consisting of a C ₆ -C ₃₀ aryl ester group and a substituted or unsubstituted C ₂ -C ₃₀ heteroaryl ester group, provided that at least one of _{R 1} , R ₂ , R ₃ , and R _{4 .} The above is an ionic group or contains an ionic group;

X and X' are each independently a simple bond, O, S, a substituted or unsubstituted C ₁ -C ₃₀ alkylene group, a substituted or unsubstituted C ₁ -C ₃₀ heteroalkylene group, a substituted or unsubstituted C ₆ - C ₃₀ arylene group, substituted or unsubstituted C ₆ -C ₃₀ arylalkylene group, substituted or unsubstituted C ₂ -C ₃₀ heteroarylene group, substituted or unsubstituted C ₂ -C ₃₀ heteroarylalkylene group , a substituted or unsubstituted C ₅ -C ₂₀ cycloalkylene group, a substituted or unsubstituted C ₅ -C ₃₀ heterocycloalkylene group, a substituted or unsubstituted C ₆ -C ₃₀ aryl ester group, and a substituted or It is selected from the group consisting of an unsubstituted C ₂ -C _{30 heteroaryl ester group,}

However, when n is 0, _{at least one of R 1} , R ₂ , R ₃ , and R ₄ is a hydrophobic functional group including a halogen element or a hydrophobic functional group.)

The step S10 may be a step of forming an MXene thin film by coating a solution in which an MXene material is dispersed on a substrate by a solution process.

The MXene material is Ti ₂ C, Ti ₂ N, Mo ₂ C,V ₂ C, Nb ₂ C, Ti ₃ C ₂ , Zr ₃ C ₂ , Ti ₄ N ₃ , V ₄ C ₃ , Nb ₄ C ₃ , Ta ₄ C ₃ and derivatives thereof.

The solution process is a spin coating method, a spray method, a dip coating method, a bar coating method, a nozzle printing method, a slot-die coating method, a gravure printing method, a cast method, or a Langmuir-Blodgett film method (LB (Langmuir-Blodgett) )) can be used.

The MXene thin film is 1 to 100 nm (or 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15, 16, 17, 18, 19, 20, The smaller of the two values selected from among 21, 22, 23, 24, 25, 26, 27, 38, 29, 30, 35, 40, 45, 50, 55, 60, 70, 80, 90, 100 nm is the lower limit. It can be formed with a thickness of a range of values with a large value as the upper limit).

The MXene thin film may be heat-treated at 100 to 200 °C to improve electrical properties.

In step S20, 100 parts by weight of a conductive polymer, 100 to 300 parts by weight of a fluorine-based material (or one of 100, 120, 150, 170, 200, 250, or 300 parts by weight), 0.5 to 5 parts by weight of a basic material (or 0.5 , 0.7, 1, 1.5, 2, 3, 4, 5 parts by weight) may be a step of coating a mixed solution on the first electrode by a solution process to form a hole injection layer thin film.

The conductive polymer is a copolymer including two or more different repeating units selected from among polythiophene, polyaniline, polypyrrole, polystyrene, polyethylenedioxythiophene, polyacetylene, polyphenylene, polyphenylvinylene and polycarbazole, and derivatives thereof. or a mixture of two or more thereof.

The basic material is naphthylamine (2-Naphtylamine), arylaniline (n-Allylaniline), aminobiphenyl (4-Aminobiphenyl), toluidine (o-Toluidine), aniline (Aniline), quinoline (Quinoline), dimethyl aniline It is selected from the group consisting of (N,N,-Diethyl aniline) and pyridine (Pyridine), and may be an amine compound or a pyridine compound having a pKa of 4-6.

The conductive polymer may be a PEDOT:PSS polymer, the fluorine-based material may be a perfluorinated ionomer (PFI), and the basic material may be aniline.

According to the present invention, a light emitting device comprising a transparent MXene electrode and a neutralized conductive polymer composition hole injection layer (n-GraHIL) uses an MXene material, which has a lower production cost than the existing ITO, with high efficiency equivalent to that of the existing ITO-based light emitting device. In the case of depositing the MXene transparent electrode on a PET substrate, it can be implemented as a flexible light emitting device, so it is possible to manufacture a flexible light emitting device with high efficiency at low cost compared to the production cost of a conventional ITO-based light emitting device.

1 is a schematic diagram showing the structure of a light emitting device according to an embodiment of the present invention.
2 is a schematic diagram showing a schematic structure of an MXene material used as a transparent electrode of a light emitting device of the present invention.
3 is a schematic diagram illustrating a process of forming a _{Ti 3} C ₂ layer by spin-coating _{Ti 3} C ₂ MXene material on a substrate for manufacturing a transparent electrode in the manufacture of a light emitting device according to an embodiment of the present invention. .
4 is an atomic force microscope (AFM) image of _{the Ti 3} C ₂ layer constituting the transparent electrode of the light emitting device according to an embodiment of the present invention.
5 is a graph of transmittance according to the thickness of the _{Ti 3} C ₂ layer in an experimental example of the present invention.
6 is a graph showing transmittance and sheet resistance according to the thickness of the _{Ti 3} C ₂ layer in an experimental example of the present invention.
7 shows the spatial surface potential difference through the Kelvin probe according to the presence or absence of heat treatment of the _{Ti 3} C ₂ layer and the heat treatment temperature in an experimental example of the present invention.
8 is a graph showing the photoluminescence current with respect to the work function according to the presence or absence of heat treatment of the _{Ti 3} C ₂ layer in an experimental example of the present invention.
9 is a schematic diagram schematically showing the configuration of _{a Ti 3} C ₂ thin film prepared in one preparation example of the present invention.
10 is a photograph showing the peeling of the _{Ti 3} C ₂ layer during spin coating of the PEDOT:PSS layer on the _{Ti 3} C ₂ layer in an experimental example of the present invention.
_{11 is an OM image of the interface between the Ti 3} C ₂ layer and the PEDOT:PSS layer in an experimental example of the present invention.
_{12 is an SEM image of the interface between the Ti 3} C ₂ layer and the PEDOT:PSS layer in an experimental example of the present invention.
13 is a photograph showing the n-GraHIL layer spin-coated without peeling on the _{Ti 3} C ₂ layer in an experimental example of the present invention.
_{14 is an OM image of the interface between the Ti 3} C ₂ layer and the n-GraHIL layer in an experimental example of the present invention.
_{15 is a graph showing transmittance of a Ti 3} C ₂ film and a layer and a Ti ₃ C ₂ /n-GraHIL film in an experimental example of the present invention.
16 is an XPS depth profile graph of a _{Ti 3} C ₂ film in an experimental example of the present invention.
17 is an XPS depth profile graph of the _{PEDOT:PSS/Ti 3} C ₂ film in an experimental example of the present invention.
18 is an XPS depth profile graph of the _{n-GraHIL/Ti 3} C ₂ film in an experimental example of the present invention.
19 is a structural diagram of an organic light emitting device according to an embodiment of the present invention.
20 is a voltage-current density graph of an MXene-based organic light-emitting device according to a manufacturing example of the present invention and an ITO-based organic light-emitting device according to a comparative example.
21 is a photocurrent efficiency graph of an MXene-based organic light-emitting device according to a manufacturing example of the present invention and an ITO-based organic light-emitting device according to a comparative example.
22 is a graph of photovoltage efficiency of an MXene-based organic light-emitting device according to a manufacturing example of the present invention and an ITO-based organic light-emitting device according to a comparative example.
23 is a light-EQE graph of an MXene-based organic light-emitting device according to a preparation example of the present invention and an ITO-based organic light-emitting device according to a comparative example.
24 is a voltage-light curve of an MXene-based organic light-emitting device according to a manufacturing example of the present invention and an ITO-based organic light-emitting device according to a comparative example.
25 is an operation view of an MXene-based organic light emitting device manufactured according to a manufacturing example of the present invention.
26 is a view of a flexible MXene-based organic light emitting device manufactured on a PET substrate according to a manufacturing example of the present invention.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

While the present invention is susceptible to various modifications and variations, specific embodiments thereof are illustrated and shown in the drawings and will be described in detail hereinafter. However, it is not intended to limit the invention to the particular form disclosed, but rather the invention includes all modifications, equivalents and substitutions consistent with the spirit of the invention as defined by the claims.

It will be understood that when an element, such as a layer, region, or substrate, is referred to as being “on” another component, it may be directly on the other element or intervening elements in between. .

Although the terms first, second, etc. may be used to describe various elements, components, regions, layers and/or regions, such elements, components, regions, layers and/or regions are not It will be understood that they should not be limited by these terms.

As used herein, the term “light emitting device” may include all devices that emit light, such as a light emitting diode, a light emitting transistor, a laser, and a polarized light emitting device. . A driving method of the device may be a DC driving method or a pulse driving method. Preferably, it may include all of the light emitting devices of the direct current driving method of 20 V or less, more preferably 15 V or less, more preferably 10 V or less.

In the present specification, "transparent electrode" means an electrode having a transmittance of 50% or more, preferably a transmittance of 80% or more.

As used herein, the "work function" refers to an energy difference between a vacuum level and a Fermi energy level. This work function corresponds to the minimum energy required to remove one electron from the conductor. Therefore, the work function is always positive. On the other hand, the HOMO (Highest Occupied Molecular Orbital) energy level defined in the organic semiconductor and the VBM (Valence Band Maximum) energy level defined in the inorganic semiconductor are displayed in a negative (-) direction from the vacuum level, All have negative values, and the difference between the vacuum level and the HOMO (or VBM) energy level is defined as ionization energy (IE), and this value has a positive value. Therefore, the ionization energy is the absolute value of the HOMO or VBM energy level.

One. MXene Light emitting device including electrode

1 is a schematic diagram showing a light emitting device according to an embodiment of the present invention.

1, the light emitting device according to the present invention includes a substrate 10, an anode 20 as a first electrode, a hole injection layer 30, a light emitting layer 40, and a cathode 50 as a second electrode .

The substrate 10 serves as a support for the light emitting device and may be made of a transparent material. In addition, the substrate may be a flexible material or a hard material, for example, glass, sapphire, quartz, silicon, polyethylene terephthalate (PET). , polystyrene (PS), polyimide (polyimide, PI), polyvinyl chloride (PVC), polyvinylpyrrolidone (PVP) or polyethylene (PE), etc., but is not limited thereto does not

The substrate 10 may be disposed under the anode or over the cathode. In other words, the anode may be formed before the cathode or the cathode may be formed before the anode on the substrate. Accordingly, the light emitting device may have both a normal structure and an inverse structure.

A first electrode 20 may be positioned on the substrate 10 .

The first electrode may be a positive electrode, and the positive electrode is a conductive film having a high work function, and includes an MXene material represented by the following Chemical Formula 1.

(In Formula 1,

M is a transition metal,

X is C or N;

T _x is a -OH, -O or -F end group located on the surface,

n is an integer from 1 to 3.)

2 is a schematic diagram showing the structure of the MXene material.

Referring to FIG. 2 , the MXene material is a carbide or nitride layer in which unit cells in which one X atom is located inside six transition metal (M) atoms arranged in an octahedral shape are two-dimensionally arranged, several nanometers thick and A two-dimensional plate-like structure having a length of several micrometers is formed. The MXene material is also expressed as _{M n+1} X _{n composition.}

Changes in the elements or end groups located on the surface of the MXene material can affect the electrical structure and properties of the MXene material. The interesting electrical and electrochemical properties of these MXene materials are applied to various fields, for example, lithium ion batteries, supercapacitors, field emission transistors, or sensors, etc. However, the MXene has not yet been applied to a light emitting device. .

Accordingly, the present invention is characterized in that the MXene material is manufactured and applied as a transparent electrode having a specification suitable for a light emitting device.

Specific examples of the MXene material include Ti _2C , Ti ₂ N, Mo ₂ C, V ₂ C, Nb ₂ C, Ti ₃ C ₂ , Zr ₃ C ₂ , Ti ₄ N ₃ , V ₄ C ₃ , Nb ₄ C ₃ , Ta ₄ C _{3 ,} etc., and derivatives derived therefrom, MXene derivatives containing three or more elements (3 atoms) derived therefrom, and the like are possible, Mohammad Khazaei et al., Current Opinion in Solid State & Materials Science 23 (2019) may include all of the materials described in 164-178, but is not limited thereto, and Ti ₃ C ₂ was used in this example. In particular, Ti ₂ C, Mo ₂ C, Ti ₃ C _2, etc. may be mainly used as electrodes for batteries and light emitting devices.

The anode including the MXene material may be prepared by, for example, coating a solution in which the MXene material is dispersed on a substrate using a solution process such as spin coating and drying it at room temperature, or forming an MXene thin film through vacuum heat treatment. However, the present invention is not limited thereto.

Since the MXene material has different electrical properties depending on the element or terminal groups located on the surface, the electrical properties can be improved by additionally changing the distribution of the terminal groups through surface treatment such as heat treatment. For example, through heat treatment Electrical properties can be improved by removing -OH and -O groups on the surface of MXene and increasing the density of -F groups.

A hole injection layer 30 may be positioned on the anode, which is the first electrode 20 . The hole injection layer 30 must have a value greater than the work function of the anode, and has a value similar to or more similar to the absolute value (ie, ionization energy value) of the HOMO (or VBM) energy level of the light emitting layer 40 to be described later. As a layer having a large work function value, it is generally formed on an anode, and functions to increase the injection or transport efficiency of holes from the anode to the light emitting layer.

As the hole injection layer 30, conventionally, a conductive polymer, PEOT:PSS, was mainly used. However, since the MXene material used as an anode in the light emitting device according to the present invention is vulnerable to acidity and moisture, when PEOT:PSS is coated on the MXene layer with a hole injection layer, the strong acidity of the PEOT:PSS (pH 1 ~ 2) and the MXene layer was peeled off and oxidized from the substrate by the solvent (see FIGS. 10 to 12 and 17).

Therefore, the hole injection layer material of the light emitting device including the MXene electrode according to the present invention lowers the acidity of the existing acidic conductive polymer solution so as not to affect the properties of the MXene layer, which is the anode, and contains the conductive polymer solution or dispersion. It is very important to reduce the amount of water present. Accordingly, the hole injection layer material of the light emitting device including the MXene electrode according to the present invention has a neutral pH by neutralizing the acidity of the conductive polymer solution or dispersion, and lowers the water content (eg, PEDOT: In the case of PSS dispersion, the solvent is When water is 100%, PEDOT:PSS dispersion is 100 parts by weight, and fluorine-based material solution of the same concentration (mainly when a solvent of 1:1 ratio of water and alcohol is used) is 100 parts by weight, the content of water in the total solvent is reduced to 75% and, when the fluorine-based material solution of the same concentration is 300 parts by weight, the content of water relative to the total solvent is reduced to 62.5%) material. In addition, it is preferable that the work function of the hole injection layer thin film is higher than the work function of the anode, and in some cases, the ionization energy of the light emitting layer (that is, the absolute value of the HOMO energy level) is usually a similar value by a difference of about 0 to 0.2 eV. It is common to have , and even if it has a value greater than the ionization energy of the emission layer, Fermi-level pinning occurs and there is no problem in hole injection.

As such a hole injection layer material, when an Au thin film deposited by thermal evaporation equipment is used as a reference electrode and measured by a Kelvin probe method (eg, using KP technology equipment), 5.6 eV or more, preferably 5.7 eV or more , more preferably having a work function of 5.8 eV or more, and having a pH of 4.0 to 10.0, for example, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3 , 7.4, 7.5, 8.0, 8.5, 9.0, 9.5, and a conductive polymer composition neutralized to a value selected from 10.0 may be used. The conductive polymer composition may be prepared by adding a fluorine-based material and a basic material to the conductive polymer to adjust the work function and pH. As a method of measuring the work function, in addition to the Kelvin Probe, an Air Photoemission Spectrometer (eg, AC2, Riken Keiki Co.) and a UV Photoelectron Spectrometer (vacuum UPS equipment) may be used, but the present invention is not limited thereto. There may be some error in the absolute value of the work function. In this embodiment, Kelvin Probe equipment (KP Technology, UK) was used to measure the work function of the hole injection layer.

The conductive polymer may include polythiophene, polyaniline, polypyrrole, polystyrene, polyethylenedioxythiophene, polyacetylene, polyphenylene, polyphenylvinylene, polycarbazole, a copolymer including two or more different repeating units of these, derivatives or blends of two or more thereof.

The fluorine-based material may be a fluorinated ionomer (FI) or a perfluorinated ionomer (PFI) represented by Formula 2 below.

In Formula 1,

0 < m ≤ 10,000,000, 0 ≤ n < 10,000,000, 0 ≤ a ≤ 20, 0 ≤ b ≤ 20;

A, B, A' and B' are each independently selected from the group consisting of C, Si, Ge, Sn, and Pb;

R ₁ , R ₂ , R ₃ , R ₄ , R ₁ ', R ₂ ', R ₃ ' and R ₄ ' are each independently hydrogen, halogen, nitro group, substituted or unsubstituted amino group, cyano group, substituted or unsubstituted C ₁ -C ₃₀ alkyl group, substituted or unsubstituted C ₁ -C ₃₀ heteroalkyl group, substituted or unsubstituted C ₁ -C ₃₀ alkoxy group, substituted or unsubstituted C ₁ -C ₃₀ heteroalkoxy group, a substituted or unsubstituted C ₆ -C ₃₀ aryl group, a substituted or unsubstituted C ₆ -C aryl group, a substituted or unsubstituted aryloxy-substituted C ₆ -C _30, substituted or unsubstituted C _{2 30} - C ₃₀ heteroaryl group, substituted or unsubstituted C ₂ -C ₃₀ heteroarylalkyl group, substituted or unsubstituted C ₂ -C ₃₀ heteroaryloxy group, substituted or unsubstituted C ₅ -C ₂₀ cyclo Alkyl group, substituted or unsubstituted C ₂ -C ₃₀ heterocycloalkyl group, substituted or unsubstituted C ₁ -C ₃₀ alkylester group, substituted or unsubstituted C ₁ -C ₃₀ heteroalkyl ester group, substituted or unsubstituted selected from the group consisting of a C ₆ -C ₃₀ aryl ester group and a substituted or unsubstituted C ₂ -C ₃₀ heteroaryl ester group, provided that at least one of _{R 1} , R ₂ , R ₃ , and R _{4 .} The above is an ionic group or contains an ionic group;

X and X' are each independently a simple bond, O, S, a substituted or unsubstituted C ₁ -C ₃₀ alkylene group, a substituted or unsubstituted C ₁ -C ₃₀ heteroalkylene group, a substituted or unsubstituted C ₆ - C ₃₀ arylene group, substituted or unsubstituted C ₆ -C ₃₀ arylalkylene group, substituted or unsubstituted C ₂ -C ₃₀ heteroarylene group, substituted or unsubstituted C ₂ -C ₃₀ heteroarylalkylene group , a substituted or unsubstituted C ₅ -C ₂₀ cycloalkylene group, a substituted or unsubstituted C ₅ -C ₃₀ heterocycloalkylene group, a substituted or unsubstituted C ₆ -C ₃₀ aryl ester group, and a substituted or It is selected from the group consisting of an unsubstituted C ₂ -C _{30 heteroaryl ester group,}

However, when n is 0, _{at least one of R 1} , R ₂ , R ₃ , and R ₄ is a hydrophobic functional group including a halogen element or a hydrophobic functional group.

The basic material may be _{an amine compound or a pyridine compound having a} pK a of 4 to 6, and specifically, the amine compound is naphtylamine (2-Naphtylamine), arylaniline (n-Allylaniline), aminobiphenyl (4-Aminobiphenyl) ), toluidine (o-Toluidine), aniline (Aniline), quinoline (Quinoline), dimethyl aniline (N,N,-Diethyl aniline) and may be at least one selected from the group consisting of pyridine (Pyridine).

Specifically, the conductive polymer composition may include PEDOT:PSS polymer, PFI, and aniline.

The conductive polymer composition comprises 100 parts by weight of a conductive polymer, 100 to 300 parts by weight of a fluorine-based material (or a value of one of 100, 120, 150, 170, 200, 250, or 300 parts by weight), 0.5 to 5 parts by weight of a basic material (or 0.5, 0.7, 1, 1.5, 2, 3, 4, 5 parts by weight) is preferably included, and when it is out of the above range, the work function (5.6 eV or more) value to be implemented in the present invention is There is a problem of dissatisfaction or deposits.

The light emitting layer 40 may be positioned on the hole injection layer 30 .

In the light emitting layer 40, holes (h) introduced from the anode and electrons (e) introduced from the cathode combine to form excitons, and light is emitted as the excitons transition to the ground state, thereby generating light emission. The emission layer may include a blue, red, or green emission material, and may include a host and a dopant. The material constituting the light emitting layer is not particularly limited, and a material commonly used in the art may be used.

Specifically, oxadiazole dimer dyes (Bis-DAPOXP), spiro compounds (Spiro-DPVBi, Spiro-6P), triarylamine compounds, bis (styryl) amine (bis(styryl)amine)(DPVBi, DSA), 4,4'-bis(9-ethyl-3-carbazovinylene)-1,1'-biphenyl (BCzVBi), perylene, 2 ,5,8,11-tetra-tert-butylperylene (TPBe), 9H-carbazole-3,3'-(1,4-phenylene-di-2,1-ethene-diyl)bis[9- Ethyl-(9C)](BCzVB), 4,4-bis[4-(di-p-tolylamino)styryl]biphenyl (DPAVBi), 4-(di-p-tolylamino)-4'-[ (di-p-tolylamino) styryl] stilbene (DPAVB), 4,4'-bis [4- (diphenylamino) styryl] biphenyl (BDAVBi), bis (3,5-difluoro- 2-(2-pyridyl)phenyl-(2-carboxypyridyl)iridium III (FIrPic) etc. (over blue) and 3-(2-benzothiazolyl)-7-(diethylamino)coumarin (Coumarin 6) ) 2,3,6,7-tetrahydro-1,1,7,7,-tetramethyl-1H,5H,11H-10-(2-benzothiazolyl)quinolizino-[9,9a,1gh] Coumarin (C545T), N,N'-dimethyl-quinacridone (DMQA), tris(2-phenylpyridine)iridium(III)(Ir(ppy)3), etc. (over green), tetraphenylnaphthacene (Rubrin: Rubrene), tris (1-phenylisoquinoline) iridium (III) (Ir (piq) ₃ ), bis (2-benzo [b] thiophen-2-yl-pyridine) (acetylacetonate) iridium (III)(Ir(btp) ₂ (acac)), tris(dibenzoylmethane)phenanthroline europium(III)(Eu(dbm) ₃ (phen)), tris[4,4′-di-tert-butyl -(2,2')-bipyridine]ruthenium(III) complex (Ru(dtb-bpy)3*2(PF6)), DCM1, DCM2, Eu(thenoyltrifluoroacetone trifluoride) ₃ (Eu(TT) A) ₃ , Butyl-6-(1,1,7,7-tetramethyl julolidyl-9-enyl)-4H-pyran) (butyl-6-(1,1,7,7-tetramethyljulolidyl-9-) enyl)-4H-pyran: DCJTB) and the like (red above) can be used. In addition, as the polymer light emitting material, such as phenylene-based, phenylene vinylene-based, thiophene-based, fluorene-based and spiro-fluorene-based polymers, etc. It may include an aromatic compound containing a polymer and nitrogen, but is not limited thereto.

In addition, the light emitting layer may include a metal halide perovskite.

The metal halide perovskite may be a material having a three-dimensional crystal structure, a two-dimensional crystal structure, or a one-dimensional crystal structure or a zero-dimensional crystal structure.

The metal halide perovskite is ABX ₃ (3D), A ₄ BX ₆ (0D), AB ₂ X ₅ (2D), A ₂ BX ₄ (2D), A ₂ BX ₆ (0D), A ₂ B ⁺ B ³⁺ X ₆ (3D), A ₃ B ₂ X ₉ (2D), or A _{n- 1} B _n X _{3n +1} (qausi-2D) (n is an integer between 2 and 6). . A may be a monovalent (monovalent) cation, B may be a metallic material, and X may be a halogen element. The quasi-2D structure may be a Ruddlesden-Popper phase or a Dion-Jacobson phase.

The monovalent (monovalent) cation may be a monovalent organic cation or an alkali metal. For example, the monovalent organic cation is an organic ammonium (RNH ₃ ) ⁺ , an organic amidinium derivative (RC(=NR ₂ )NR ₂ ) ⁺ , an organic guanidinium derivative (R ₂ NC(=NR ₂ )NR ₂ ) ⁺ , organic diammonium (C _x H _2x-n+4 )(NH ₃ ) _n ⁺ _, ((C _x H2 _{x + 1} ) _n NH ₃ )(CH ₃ NH ₃ ) _n ⁺ , (RNH ₃ ) ₂ ⁺ , (C _n H _{2n + 1} NH ₃ ) ₂ ⁺ , (CF ₃ NH ₃ ) ⁺ , (CF ₃ NH ₃ ) _n ⁺ , ((C _x F _2x+1 ) _n NH ₃ ) ₂ (CF _{3 )} NH ₃ ) _n ⁺ , ((C _x F _{2x + 1} ) _n NH ₃ ) ₂ ⁺ Or (C _n F _{2n + 1} NH ₃ ) ₂ ⁺ (x, n is an integer greater than or equal to 1, R = hydrocarbon derivative, H, F, Cl, Br, I) and combinations thereof, but is not limited thereto. The alkali metal may be Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , Cs ⁺ , Fr ^{+ ,} and combinations thereof, but is not limited thereto.

Also preferably, the organic cation is acetamidinium, azaspironanium, benzene diammonium, benzylammonium, butanediammonium, isobutylammonium ( iso-butylammonium), n-butylammonium, t-butylammonium, cyclohexylammonium, cyclohexylmethylammonium, diazobicyclooctanedinium, diethylammonium, N,N-diethylethane diammonium, N,N-diethylpropane diammonium, dimethylammonium, N, N,N-dimethylethane diammonium, dimethylpropane diammonium, dodecylammonium, ethanediammonium, ethylammoniuium, 4-fluoro-benzyl Ammonium (4-fluoro-benzylammonium), 4-fluoro-phenylethylammonium (4-fluoro-phenylethylammonium), 4-fluoro-phenylammonium (4-fluoro-phenylammonium), formamidinium, guanine guanidinium, hexanediammnium, hexylammonium, imidazolium, 2-methoxyethylammonium, 4-methoxy-phenylethylammonium (4-methoxy) -phenlylethylammonium), 4-methoxy-phenylammoni um), methylammonium, morpholinium, octylammonium, pentylammonium, piperazinediium, piperidinium, propanediammonium , iso-propylammonium, di-isopropylammonium, n-propylammonium, pyridinium, 2-pyrrole-1ium-1-ie Tylammonium (2-pyrrolidin-1-ium-1-yethylammonium), pyrrolidinium, quinclidin-1-ium, 4-trifluoromethyl-benzylammonium (4- trifluoromethyl-benzylammonium), 4-trifluoromethyl ammonium, and quaternary ammonium cations such as Benzalkonium chloride, Dimethyldioctadecylammonium chloride, Trimethylglycine, Choline, and combinations thereof, but are not limited thereto no.

B may be a divalent transition metal, a rare earth metal, an alkaline earth metal, a monovalent metal, a combination of a trivalent metal, an organic material (monovalent, divalent, or trivalent cation), and combinations thereof. In addition, preferably the divalent transition metal, rare earth metal, an alkaline earth metal ^{+ 2} Be, Mg ^{2 +,} Ca ^2+, Sr ^{+ 2,} Ba ^{+ 2,} Ra ^{2 +,} Mn ^{+ 2,} Fe ^{+ 2,} Co ^{2 +, Ni 2 +, Cu} 2 +, Zn 2 +, Ru 2 +, Bi 2 +, Pd 2 +, Cd 2 +, Pt 2 +, Hg 2+, Ge 2 +, Sn 2 +, Pb 2 + , ⁺ Se ^2, Te ^{2 +, 2 +,} and Po is not a combination thereof, but is limited. The monovalent metal may be Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , Cs ⁺ , Fr ⁺ , Ag ⁺ , Hg ⁺ , Ti ⁺ and combinations thereof, and the trivalent metal is Cr ^{3 +} , Fe ^{3 +,} Co ^{+ 3,} Ru ^{+ 3,} Rh ^{+ 3,} Ir ^{+ 3,} Au ^{3 +,} Al ^{3 +,} Ga ^3+, In ^3+, Ti ^3+, As ^3+, Sb ^3+, Bi ³⁺ and It may be a combination of these.

In addition, X may be F ^- , Cl ^- , Br ^- , I ^- , At ^-, and combinations thereof.

The metal halide perovskite may be in the form of a metal halide perovskite bulk thin film having a polycrystal form, or may be in the form of a metal halide perovskite nanocrystal that is easily dispersed in a colloidal state even in a solution.

The metal halide perovskite nanocrystal may further include a plurality of organic ligands surrounding the halide metal halide perovskite nanocrystal. At this time, the organic ligands are substances used as surfactants, and alkyl halides (Alkyl Halide), alkyl ammonium halide (Alkyl Ammonium Halide), amine ligands (Amine Ligand) and carboxylic acid (Carboxylic Acid) or phosphonic acid (Phosphonic Acid) may be included.

Ligand refers to a generic term for an ion or molecule capable of binding to a central atom in a Dative complex. The ligand binds to the surface of the nanoparticles and serves to precisely control the shape and size of the nanoparticles. For a detailed description of the ligand, refer to [Journal of the American Chemistry Society, 2013, 135, 49, pp 18536-18548]. The ligand binding to the surface of the nanoparticles may correspond to an L-type ligand, an X-type ligand, or a Z-type ligand depending on the mode of defecting with the surface of the nanoparticles. L-type ligand for donating two electrons for dative bonding, X-type ligand for donating one electron to the cation site on the surface of nanoparticles to form a covalent bond, and two electrons on the surface of nanoparticles The acceptor of is a Z-type ligand.

A surfactant is an amphiphatic substance having two opposite functional groups, hydrophilic and hydrophobic, in the same molecule, adsorbed at the interface between liquid and gas, liquid and liquid, or liquid and solid. It can play a role in the appearance of various physical phenomena. The role of the surfactant may serve to lower the surface tension, emulsify, improve wettability, foamability, or solubilization. have. In particular, when the surfactant acts as a ligand by binding to the surface of the nanoparticles through a coordination bond, the dispersibility of the nanoparticles can be increased. Examples of surfactants include anionic surfactants (e.g., ammonium lauryl sulfate, sodium lauryl sulfate, sodium dodecyl sulfate, sodium laureth sulfate, sodium myreth sulfate), sulfonates (e.g. dioctyl sodium sulfosuccinate, perfluorooctanesulfonate, perfluorobutanesulfonate, linear alkylbenzne sulfates). ), phosphate esters, carboxylates (eg, sodium stearate, sodium lauroyl sarcosinate, perfluorononanoate, perfluorooctanoate), cationic surfactants (primary, secondary, tertiary, quatenary containing ammonium cation), and Benzalkonium chloride, Quaternary ammonium cations such as dimethyldioctadecylammonium chloride, trimethylglycine, and choline, and amphoteric (Zwitterionic or amphoteric) surfactants having both cation and anion in the same substance, and fatty alcohols cetyl alcohol, stearyl alcohol, cetostearyl alcohol (consisting predominantly of cetyl and stearyl alcohols), and nonionic surfactants such as long chain alcohols such as oleyl alcohol.

The alkyl halide may have the structure of alkyl-X. In this case, the halogen element corresponding to X may include Cl, Br, or I. Further, at this time of the alkyl structure is a primary alcohol (primary alcohol) having a structure such as acyclic alkyl _{(acyclic alkyl), C n H} 2n + 1 OH having the structure C _n H _{2n + 1,} the secondary alcohol (secondary alcohol) , tertiary alcohol, alkylamine having an alkyl-N structure (ex. Hexadecyl amine, 9-Octadecenylamine 1-Amino-9-octadecene (C ₁₉ H ₃₇ N)), p-substituted aniline (p-substituted aniline), phenyl ammonium, or fluorine ammonium.

The amine ligand is N,N-diisopropylethylamine, ethylenediamine, hexamethylenediamine, methylamine, hexylamine, oleyl Amine (Oleylamine), N,N,N,N-tetramethyleneethylenediamine (N,N,N,N-tetramethylenediamine), triethylamine, diethanolamine, 2,2-(ethylenediamine) oxyl) bis- (ethylamine) (2,2- (ethylenedioxyl) bis- (ethylamine)) may be selected from, but is not limited thereto.

The alkylammonium halide (Alkyl Ammonium Halide or alkylammonium salt) includes methylammonium chloride, dimethylammonium bromide, and octylammonium bromide. fluoride, tetrabenzylammonium acetate). However, it is not limited thereto.

The carboxylic acid is 4,4'-azobis(4-cyanopaleric acid) (4,4'-Azobis(4-cyanovaleric acid)), acetic acid, 5-minosalic acid (5-Aminosalicylic acid), Acrylic acid, L-Aspentic acid, 6-Bromohexanoic acid, Promoacetic acid, Di Chloro acetic acid, Ethylenediaminetetraacetic acid, Isobutyric acid, Itaconic acid, Maleic acid, r-maleimido Butyric acid (r-Maleimidobutyric acid), L-Malic acid (L-Malic acid), 4-nitrobenzoic acid (4-Nitrobenzoic acid), 1-Pyrenecarboxylic acid (1-Pyrenecarboxylic acid) or oleic acid It may contain oleic acid.

The phosphonic acid is n-hexylphosphonic acid, n-octylphosphonic acid, n-decylphosphonic acid, n-dodecylphosphonic acid (n- dodecylphosphonic acid), n-tetradecylphosphonic acid (n = tetradecylphosphonic acid), n-hexadecylphosphonic acid (n-hexadecylphosphonicacid), n-octadecylphosphonic acid (n-octadecylphonic acid), but may be selected from, However, the present invention is not limited thereto.

The organic ligand may be in a fluorinated form. For example, the organic ligand is 2-fluorophenylboronic acid (2-fluorophenylbornic acid), 3,5-diformyl-2-fluorophenylboronic acid (3,5-diformyl-2-fluorophenylboronic acid) , 3-chloro-4-fluorophenylboronic acid (3-chloro-4-fluorophenylboronic acid), 4-cyano-3 fluorobenzoic acid (4-cyano-3-fluprpbenzoic acid), L-Fmoc-3 -Fluorophenylalanine (L-Fmoc-3-fluorophenylalanine), L-Fmoc-4-fluorophenylalanine (L-Fmoc-4-fluorophenylalanine), methyl-6-fluorochromone-2-carboxylic acid (Methyl 6 -fluorochromone-2-carboxylic acid), 4-fluorobenzoic acid (4-fluorobenzoic acid), 2-fluorobenzoic acid (2-fluorobenzoic acid), 2-fluoro benzylamine (2-fluoro benzylamine), 2- 2-fluorocinnamic acid, 2-fluorophenyl isothiocyanate, 4-fluorobenzenesulfonic acid, 4-fluorobenzylamine ( 4-flurobenzylamine), 4-fluorophenyl isothiocyanate, 4-fluorophenylacetic acid, fluorocinnamic acid, (3- Fluoro-4-methylphenyl)acetic acid ((3-Fluoro-4-methylphenyl)acetic acid), (3-fluoro-5-isopropoxyphenyl)boronic acid ), (3-fluoro-5-methoxycarbonylphenyl)boronic acid ((3-fluoro-5-methoxycarbonylphenyl)boronic acid), (3 -Fluoro-5-methylphenyl)boronic acid ((3-fluoro-5-methylphenyl)boronic acid), (4-fluoro-2-methoxyphenyl)oxoacetic acid acid), (4-Fluoro-3-methoxyphenyl)acetic acid), (4-fluoro-3-methoxyphenyl)boronic acid ((4-fluoro -3-methoxyphenyl) boronic acid) and combinations thereof, but is not limited thereto.

Also preferably, the fluorinated organic compound may be in the form of a perfluorinated compound. The perfluorinated compound includes perfluorinated alkyl halides, perfluorinated aryl halides, fluorochloroalkenes, perfluoroalcohols, perfluoroamines, perfluorinated carbs. It may be an acid (perfluorocarboxylic acid), perfluorosulfonic acid (perfluorosulfonic acid), or a derivative thereof, but is not limited thereto.

The perfluorinated alkyl halides and perfluorinated aryl halides include trifluoroiodomethane, pentafluoroethyl iodide, and perfluorooctyl bromide. , perflubron), dichlorodifluoromethane (dichlorodifluoromethane) and derivatives thereof, but is not limited thereto.

The fluorochloroalkene may be chlorotrifluoroethylene, dichlorodifluoroethylene, and derivatives thereof, but is not limited thereto.

The perfluorocarboxylic acid is trifluoroacetic acid, heptafluorobutryric acid, pentafluorobenzoic acid, perfluorooctanoic acid, It may be perfluorononanoic acid and derivatives thereof, but is not limited thereto.

The perfluorosulfonic acid is triflic acid, perfluorobuanesulfonic acid, perfluorobutane sulfonamide, perfluorooctanesulfonic acid, and derivatives thereof may be, but is not limited thereto.

The ligand may be trioctylphosphine oxide (TOPO), trioctylphosphine (TOP), triethylphosphine oxide, tributylphosphine oxide, and derivatives thereof. However, the present invention is not limited thereto.

Therefore, as described above, the alkyl halide used as a surfactant to stabilize the surface of the precipitated halide metal halide perovskite becomes an organic ligand surrounding the surface of the halide metal halide perovskite nanocrystal. On the other hand, when the length of the alkyl halide surfactant is short, the size of the formed nanocrystals becomes large, so it can be formed to exceed 100 nm, further 300 nm, and further 1 μm, and in large nanocrystals. Due to thermal ionization and delocalization of charge carriers, there may be a fundamental problem in that excitons do not go to light emission but are separated into free charges and annihilated. Therefore, it is possible to control the size of the halide metal halide perovskite nanocrystals formed by using an alkyl halide of a certain length or more as a surfactant to a certain size or less (ie, 100 nm or less, preferably 30 nm or less).

A hole transport layer may be formed between the hole injection layer 30 and the light emitting layer 40 .

The hole transport layer preferably includes an arylamine derivative or a polymer including the same. More preferably, the hole transport layer includes a polymer including carbazole or a derivative thereof, phenoxazine or a derivative thereof, phenothiazine or a derivative thereof, or a carbazole group, a phenoxazine group or a phenothiazine group. Even more preferably, the hole transport layer is 1,3,5-tricarbazolylbenzene, 4,4'-carbazolylbiphenyl, polyvinylcarbazole, m-biscarbazolylphenyl, 4,4'-biscarbazolyl -2,2'-dimethylbiphenyl, 4,4',4"-tri(N-carbazolyl)triphenylamine, 1,3,5-tri(2-carbazolylphenyl)benzene, 1,3,5 -tris(2-carbazolyl-5-methoxyphenyl)benzene, bis(4-carbazolylphenyl)silane, N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1 -Biphenyl]-4,4'diamine (TPD), N,N'-di(naphthalen-1-yl)-N,N'-diphenylbenzidine (α-NPD), N,N'-diphenyl- N,N'-bis(1-naphthyl)-(1,1'-biphenyl)-4,4'-diamine (NPB), IDE320 (Idemitsu), poly(9,9-dioctylfluorene) -co-N-(4-butylphenyl)diphenylamine) and poly(9,9-dioctylfluorene-co-bis-(4-butylphenyl-bis-N,N-phenyl-1,4-phenyl) Any one selected from the group consisting of rendiamine, poly(9,9-dioctylfluorene-co-N,N-di(phenyl)-N,N-di(3-carboethoxyphenyl)benzidine, and derivatives thereof Including, but not limited to, the above.

Meanwhile, an electron injection layer and/or an electron transport layer may be additionally positioned on the light emitting layer 40 .

The electron injection layer and/or the electron transport layer are layers having an absolute LUMO value between the work function of the cathode and the absolute value (ie, electron affinity) of the lowest unoccupied molecular orbital (LUMO) energy level of the light emitting layer. It functions to increase the efficiency of injection or transport of electrons into the light emitting layer. At this time, the LUMO energy level value is a negative number because it is a value expressed in the negative (-) direction from the vacuum level, and the absolute value is a positive number as the electron affinity. When comparing energy levels, a negative value is compared, and when comparing an absolute value, a positive value is compared.

Materials used in conventional light emitting devices may be commonly applied to the electron injection layer or the electron transport layer.

The electron injection layer may be, for example, LiF, NaCl, CsF, Li ₂ O, BaO, BaF ₂ , or Liq (lithium quinolate).

The electron transport layer is a quinoline derivative, in particular tris(8-hydroxyquinoline) aluminum (tris(8-hydroxyquinoline) aluminum: Alq ₃ ), bis(2-methyl-8-quinolinolate)-4-(phenylphenolato) Aluminum (Bis(2-methyl-8-quinolinolate)-4-(phenylphenolato)aluminium: Balq), bis(10-hydroxybenzo [h] quinolinato) beryllium (bis(10-hydroxybenzo [h] quinolinato)- beryllium: Bebq ₂ ), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline: BCP), 4, 7-diphenyl-1,10-phenanthroline (4,7-diphenyl-1,10-phenanthroline: Bphen), 2,2',2"-(benzene-1,3,5-triyl)-tris (1-phenyl-1H-benzimidazole) ((2,2',2"-(benzene-1,3,5-triyl)-tris(1-phenyl-1H-benzimidazole: TPBI), 3-(4) -biphenyl)-4-(phenyl-5-tert-butylphenyl-1,2,4-triazole (3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4- triazole: TAZ), 4-(naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (4-(naphthalen-1-yl)-3,5-diphenyl-4H -1,2,4-triazole: NTAZ), 2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (2,9-bis(naphthalen-2- yl)-4,7-diphenyl-1,10-phenanthroline: NBphen), tris(2,4,6-trimethyl-3-(pyridin-3-yl)phenyl)borane (Tris(2,4,6-trimethyl) -3-(pyridin-3-yl)phenyl)borane: 3TPYMB), phenyl-dipyrenylphosphine oxide (POPy2), 3, 3',5,5'-tetra[(m-pyridyl)-phen-3-yl]biphenyl (3,3',5,5'-tetra[(m-pyridyl)-phen-3-yl] biphenyl: BP4mPy), 1,3,5-tri[(3-pyridyl)-phen-3-yl]benzene (1,3,5-tri[(3-pyridyl)-phen-3-yl]benzene: TmPyPB), 1,3-bis[3,5-di(pyridin-3-yl)phenyl]benzene (1,3-bis[3,5-di(pyridin-3-yl)phenyl]benzene: BmPyPhB), Bis(10-hydroxybenzo[h]quinolinato)beryllium (Bis(10-hydroxybenzo[h]quinolinato)beryllium: Bepq2), diphenylbis(4-(pyridin-3-yl)phenyl)silane (Diphenylbis (4-(pyridin-3-yl)phenyl)silane: DPPS) and 1,3,5-tri(p-pyrid-3-yl-phenyl)benzene (1,3,5-tri(p-pyrid-) 3-yl-phenyl)benzene: TpPyPB), 1,3-bis[2-(2,2'-bipyridin-6-yl)-1,3,4-oxadiazo-5-yl]benzene (1 ,3-bis[2-(2,2'-bipyridine-6-yl)-1,3,4-oxadiazo-5-yl]benzene : Bpy-OXD), 6,6'-bis[5-(bi Phenyl-4-yl)-1,3,4-oxadiazo-2-yl]-2,2'-bipyridyl (6,6'-bis[5-(biphenyl-4-yl)-1, 3,4-oxadiazo-2-yl]-2,2'-bipyridyl: BP-OXD-Bpy), TSPO1(diphenylphosphine oxide-4-(triphenylsilyl)phenyl), TPBi(1,3,5-tris(N-) Phenylbenzimidazol-2-yl)benzene), tris(8-quinolinolate)aluminum (Alq3), 2,5-diaryl silol derivative (PyPySPyPy), perfluorinated compound (PF-6P), COTs ( Octasubstituted cyclooctatetraene) and the like.

The hole injection layer, the hole transport layer, the electron injection layer or the electron transport layer is a spin coating method, a spray method, a dip coating method, a bar coating method, a nozzle printing method, a slot-die coating method, a gravure printing method, a cast method or a Langmuir method. - It may be formed by performing a method arbitrarily selected from among various known methods, such as a bloodjet film method (LB (Langmuir-Blodgett)). In this case, conditions and coating conditions for forming the thin film may vary depending on the target compound, the structure and thermal properties of the target layer, and the like.

Next, the second electrode 50 may be positioned on the emission layer 40 or the electron transport layer or the electron injection layer. For example, when the first electrode 10 is an anode, the second electrode 50 may be a cathode.

When the second electrode is a negative electrode, for example, the second electrode is lithium (Li), magnesium (Mg), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), and the like. The second electrode may be formed using a sputtering method, a vapor deposition method, or an ion beam deposition method.

2. Manufacturing method of light emitting device

A method of manufacturing a light emitting device according to an embodiment of the present invention

forming a first electrode including an MXene material on a substrate (S10);

forming a hole injection layer with a conductive polymer composition including a conductive polymer, a fluorine-based material and a basic material on the first electrode (S20);

forming a light emitting layer on the hole injection layer (S30); and

and forming a second electrode on the light emitting layer (S40).

Hereinafter, the present invention will be described step by step.

First, step S10 is a step of forming the first electrode 20 including the MXene material on the substrate 10 using a solution process.

The solution process is a spin coating method, a spray method, a dip coating method, a bar coating method, a nozzle printing method, a slot-die coating method, a gravure printing method, a cast method, or a Langmuir-Blodgett film method (LB (Langmuir-Blodgett) )), and the like, may be formed by arbitrarily selected from a variety of known methods.

Specifically, the first electrode 20 may be manufactured by spin-coating a solution in which an MXene material is dispersed on a substrate to form a thin conductive electrode film, and then drying it at room temperature or vacuum heat treatment.

In this case, since the description of the substrate and the MXene material is the same as described above, a detailed description will be omitted to avoid overlapping description.

For use as a transparent electrode for a light emitting device of the present invention, the formed MXene thin film is 1 to 100 nm (or 1,2,3,4,5,6,7,8,9,10,11,12,13,14) ,15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 38, 29, 30, 35, 40, 45, 50, 55, 60, 70, 80, 90 , the small value of the two values selected from among 100 nm can be formed with a thickness of the range where the large value is the upper limit as the lower limit), the transmittance of the thin film is 50 to 95%, and the sheet resistance is 10 to 300 ohm/sq ( or 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 200, 250, or 300 ohm/sq).

The electrical properties of the formed MXene thin film can be improved by vacuum annealing at 100 to 200 °C for 1 to 2 hours.

Next, step S20 is a step of forming the hole injection layer 30 on the first electrode 20 .

As described above, the hole injection layer is neutralized in acidity in the solution so as not to affect the properties of the MXene layer, which is the anode, and has a neutral pH (values of 4.0 to 10.0, or 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 6.6 , 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0 desirable. The hole injection layer material has a work function of 5.6 eV or more, preferably 5.7 eV or more, more preferably 5.8 eV, neutralized to pH 4.0-10.0 in a dispersion solution using a polar solvent such as water and alcohol. A conductive polymer composition (neuralized gradient hole injection layer: n-GraHIL) may be used, and the conductive polymer composition may be prepared by adding a fluorine-based material and a basic material to the conductive polymer to adjust the work function and pH.

The formation of the hole injection layer may also be performed using a solution process. The solution process is a spin coating method, a spray method, a dip coating method, a bar coating method, a nozzle printing method, a slot-die coating method, a gravure printing method, a cast method, or a Langmuir-Blodgett film method (LB (Langmuir-Blodgett) )), and the like, may be formed by arbitrarily selected from a variety of known methods.

Specifically, 100 parts by weight of a conductive polymer, 100 to 300 parts by weight of a fluorine-based material (or a value of one of 100, 120, 150, 170, 200, 250, or 300 parts by weight), 0.5 to 5 parts by weight of a basic material (or 0.5, 0.7, 1, 1.5, 2, 3, 4, 5 parts by weight) is applied to the mixed solution on the first electrode to form a hole injection layer on the first electrode by coating.

Since the description of the conductive polymer, the fluorine-based material, and the basic material is the same as described above, a detailed description thereof will be omitted to avoid overlapping descriptions.

Next, S30 is a step of forming an emission layer on the hole injection layer, and S40 is a step of forming a second electrode on the emission layer.

In the method for manufacturing a light emitting device according to the present invention, an electrode layer including an MXene material is formed as a first electrode (anode), and as a hole injection layer, the weight portion of moisture is as low as 25% or less of the total solution weight, 5.6 eV or more, preferably preferably have a work function of 5.7 eV or more, more preferably 5.8 eV or more, and have a pH of 4.0 to 10.0 (such as 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, It is characterized in that an n-GraHIL layer containing a conductive polymer composition neutralized to a value selected from among 7.3, 7.4, 7.5, 8.0, 8.5, 9.0, 9.5, and 10.0) is formed, in addition to a light emitting layer and a second electrode (cathode) The step of forming may be performed according to a method known in the art.

The light emitting device according to the present invention uses an MXene transparent electrode, which has a lower production cost than conventional ITO, and a neutralized conductive polymer composition hole injection layer (n-GraHIL). When the electrode is deposited on a PET substrate, it can be implemented as a flexible organic light emitting device, and thus a highly efficient flexible organic light emitting device can be manufactured at low cost compared to the production cost of a conventional ITO-based organic light emitting device.

Hereinafter, the present invention will be described in detail with reference to Preparation Examples and Experimental Examples. However, the following Examples and Experimental Examples are merely illustrative of the present invention, and the content of the present invention is not limited by the following Examples and Experimental Examples.

< manufacturing example One : MXene Preparation of Electrodes>

The glass substrate was sonicated for 10 minutes while immersed in acetone and isopropyl alcohol (IPA), respectively. The surface of the substrate was treated with ultraviolet ozone for 10 minutes.

As MXene material, 250 μL of Ti ₃ C ₂ solution (14 mg/mL) was applied on the substrate and equilibrated for 30 seconds before spin coating. Next, as shown in FIG. 3 , the applied Ti ₃ C ₂ solution was spin-coated at 6000 rpm for 30 seconds and then at 7000 rpm for 5 seconds to form a thin conductive electrode film. The formed Ti ₃ C ₂ film was dried at room temperature, or dried by vacuum heat treatment at 100° C. for 1 hour or 200° C. for 2 hours.

Manufactured Ti ₃ C ₂ The electrodes were stored in a nitrogen glove box at room temperature.

< comparative example 1>

An ITO electrode used as a transparent electrode of a conventional light emitting device was used.

< Experimental example One : MXene Electrode Characterization>

Manufactured Ti ₃ C ₂ In the electrode, the Ti ₃ C ₂ layer was measured with an atomic force microscope (AFM) and is shown in FIG. 4 .

4 is an atomic force microscope (AFM) image of _{the Ti 3} C ₂ layer constituting the transparent electrode of the light emitting device according to an embodiment of the present invention.

As shown in FIG. 4 , _{it was confirmed that the Ti 3} C ₂ thin film was formed with a uniform thickness.

Next, changes in transmittance and sheet resistance according to the thickness of the _{Ti 3} C _{2 layer were measured and shown in FIGS. 5 and 6 .}

5 is a graph of transmittance according to the thickness of the _{Ti 3} C ₂ layer in an experimental example of the present invention.

6 is a graph showing transmittance and sheet resistance according to the thickness of the _{Ti 3} C ₂ layer in an experimental example of the present invention.

As shown in Figs. 5 and 6, Ti ₃ the transmission and sheet resistance proportional to the thickness of the C ₂ layer is increased or decreased to it, to form a transparent electrode suitable for the organic light-emitting device (OLED), a spin-coated Ti ₃ Transmittance and sheet resistance can be controlled by controlling the thickness of the C _{2 layer.} Specifically, as the MXene material, _{the thickness of the Ti 3} C ₂ layer was 1 to 100 nm (1,2,3,4,5,6,7,8,9,10,11,12,13,14,15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 38, 29, 30, 35, 40, 45, 50, 55, 60, 70, 80, 90, 100 nm) By controlling, transmittance 50-95% (50%, 55%, 60%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80% , 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 95%), sheet resistance 10~300 ohm/sq (10, 20, 30, 40 , 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 200, 250, 300 ohm/sq).

< Experimental example 2 : MXene Changes in properties due to heat treatment of electrodes>

Next, in order to find out the change in characteristics according to annealing after the formation of the Ti ₃ C _{2 thin film, the following experiment was performed.}

First, when the Ti ₃ C ₂ thin film is formed and dried at room temperature in the drying step, or dried by vacuum heat treatment at 100° C. for 1 hour or 200° C. for 2 hours, the spatial surface potential is measured through a Kelvin probe. 7, and the photoluminescence current according to the work function was measured and shown in FIG.

7 shows the spatial surface potential difference through the Kelvin probe according to the presence or absence of heat treatment of the _{Ti 3} C ₂ layer and the heat treatment temperature in an experimental example of the present invention.

8 is a graph showing the photoluminescence current with respect to the work function according to the presence or absence of heat treatment of the _{Ti 3} C ₂ layer in an experimental example of the present invention.

_{7 and 8, the work function of the Ti 3} C ₂ electrode freshly prepared without heat treatment shows a higher work function than the conventional ITO electrode, and the work function increases as the heat treatment is performed at 100 ° C. and 200 ° C. appear.

9 is a schematic diagram schematically showing the configuration of _{a Ti 3} C ₂ thin film prepared in one preparation example of the present invention.

9, the prepared Ti ₃ C ₂ thin film shows a layered structure in which titanium layers and carbon layers are alternately stacked, and terminal groups of -OH, -O and -F are formed on the surface of the titanium layer.

Thus, the work function and conductivity by removing the Ti ₃ C ₂ thin film formed after the heat treatment (annealing) a -OH, -O, -F terminal group of -OH, and -O end group in the thin film surface by Ti ₃ C ₂ It can be improved to be suitable for an electrode of an organic light emitting device.

< manufacturing example 2: Neutralized conductive polymer composition containing hole injection layer Manufacturing>

Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (hereinafter, PEDOT:PSS) polymer solution (solvent: water) with aniline and perfluorinated ionomer (PFI) (alcohol and Nafion, a mixed solvent containing water) was added. At this time, the pH was adjusted to about 6 by adding 100 parts by weight of the PEDOT:PSS dispersion, 1.5 parts by weight of aniline, and 100 parts by weight of Nafion (PFI).

The prepared polymer solution _{was applied on a Ti 3} C ₂ thin film, spin-coated, and dried to prepare a hole injection layer (n-GraHIL) including a neutralized conductive polymer composition.

< comparative example 2>

A PEDOT:PSS polymer solution dispersed in conventional water was applied on a Ti ₃ C ₂ thin film, spin-coated, and dried to prepare a hole injection layer.

< Experimental example 3: hole injection layer pH MXene Effect on electrode>

In the light emitting device including the MXene electrode according to the present invention, since the MXene electrode is easily oxidized in a humid or acidic environment, it is very important to control the pH of the hole injection layer located on the MXene electrode.

Accordingly, in order to investigate the effect of the pH of the hole injection layer positioned on the MXene electrode on the MXene electrode, the following experiment was performed.

First, as shown in Comparative Example 2, for the _{formation of a hole injection layer on the Ti 3} C ₂ electrode prepared in Preparation Example 1 as the MXene electrode, a solution in which PEDOT:PSS was dispersed in water was mixed with the Ti ₃ C ₂ electrode. A PEDOT:PSS thin film was formed by coating and spin coating, and the formed thin film was observed and shown in FIG. 10, and _{the interface between the Ti 3} C ₂ layer and the PEDOT:PSS layer was examined by optical microscopy (OM) and scanning electron microscopy. It was observed by (SEM) and shown in FIGS. 11 and 12, respectively. At this time, the pH of the PEDOT:PSS layer was about 1-2.

As a result, as shown in FIGS. 10 to 12, PEDOT on the Ti layer ₃ C _2: C ₃ showed that the Ti layer ₂ is developed to be peeled off from the substrate during spin-coating the PSS layer.

This is considered to be due to the penetration of water into the _{Ti 3} C ₂ layer due to the hydrophilicity =OH and -O end groups on the surface of the _{Ti 3} C _{2 thin film and the acidic properties of PEDOT:PSS.}

Next, as shown in Preparation Example 2, as the MXene electrode, _{in order to form a hole injection layer on the Ti 3} C ₂ electrode prepared in Preparation Example 1, a solution containing a neutralized conductive polymer composition was spin-coated to form a hole injection layer. was formed, and the formed thin film was observed and shown in FIG. 13, and _{the interface between the Ti 3} C ₂ layer and the neutralized conductive polymer composition layer (n-GraHIL) was observed with an optical microscope (OM) and shown in FIG. 14 . At this time, the pH of the n-GraHIL was about 6.

As a result, as shown in Figure 13, the conductive polymer composition layer the pH is neutralized with about 6 was uniformly coated on the Ti ₃ C ₂ layer without peeling of the Ti ₃ C ₂ layer, 14, an interface In addition, it can be seen that the coating was successfully performed densely without cracking.

Accordingly, the transmittance of the Ti ₃ C ₂ thin film and the Ti ₃ C ₂ /n-GraHIL thin film was measured and shown in FIG. 15 .

As shown in FIG. 15 , the transmittance of the Ti ₃ C ₂ thin film and the Ti ₃ C ₂ /n-GraHIL thin film is almost identical, so that the n-GraHIL thin film is a transparent thin film that does not affect the transmittance of the _{Ti 3} C _{2 thin film.} formation can be seen.

Further, when the hole injection layer coated on the Ti film ₃ C ₂ through the XPS depth profile analysis to measure the degree of oxidation of the Ti ₃ C ₂ film.

16 is an XPS depth profile graph of a _{Ti 3} C ₂ thin film in an experimental example of the present invention.

17 is an XPS depth profile graph of a _{PEDOT:PSS/Ti 3} C ₂ thin film in an experimental example of the present invention.

18 is an XPS depth profile graph of an _{n-GraHIL/Ti 3} C ₂ thin film in an experimental example of the present invention.

As shown in FIGS. 16 to 18 , in the PEDOT:PSS/Ti ₃ C ₂ thin film, the atomic concentration of oxygen rapidly increases over time, and _{it can be seen that the Ti 3} C ₂ thin film is oxidized, but n-GraHIL Since the atomic concentration of oxygen in the /Ti ₃ C ₂ thin film does not change relatively much, it can be seen that the oxidation of _{the Ti 3} C _{2 thin film is small.}

Therefore, it can be seen _{that the light emitting device including the Ti 3} C ₂ electrode according to the present invention preferably uses a hole injection layer (n-GraHIL) including a neutralized conductive polymer composition.

< manufacturing example 3: MXene Manufacturing of Light-Emitting Device>

_{Ti 3} C ₂ prepared in Preparation Example 1 On the transparent electrode (anode), the neutralized conductive polymer hole injection layer (n-GraHIL) prepared in Preparation Example 2 was spin-coated to prepare a 100-nm-thick film. In order to manufacture the organic light emitting device, the substrate/anode/hole injection layer (HIL) sample was transferred to a thermal evaporator.

Next, TAPC(15 nm)/TCTA:Ir(ppy) ₂ acac(5 nm, 97:3 volume ratio)/CBP:Ir(ppy) ₂ acac(5 nm, 96:4, by volume)/TPBi(55 nm) was ^{deposited using a thermal evaporator under 5.0×10 -7} torr. (where TAPC is 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane and TCTA is tris(4- Carbazoyl-9-ylphenyl)amine, CBP is 4,4'-bis(N-carbazolyl)-1,1'-biphenyl, and TPBi is 2,2,2-(1,3,5- benzenetriyl)tris-(1-phenyl-1-H-benzimidazole).)

Next, lithium fluoride (LiF) (1 nm)/aluminum (100 nm) metal electrodes were sequentially deposited.

A structural diagram of the manufactured light emitting device is shown in FIG. 19 .

< comparative example 3: ITO system Manufacturing of Light-Emitting Device>

A light emitting device was manufactured in the same manner as in Preparation Example 3, except that a PEDOT:PSS polymer solution was spin-coated on the ITO transparent electrode (anode) of Comparative Example 1 as a conductive polymer hole injection layer.

< Experimental example 4: Measurement of electrochemical properties of light emitting devices>

The electrochemical properties of the Ti ₃ C ₂ organic light-emitting device prepared in Preparation Example 3 and the ITO-based organic light-emitting device prepared in Comparative Example 3 were measured, and are shown in FIGS. 20 to 24 and Table 1 below.

20 is a voltage-current density graph of an MXene-based organic light-emitting device according to a manufacturing example of the present invention and an ITO-based organic light-emitting device according to a comparative example.

21 is a photocurrent efficiency graph of an MXene-based organic light-emitting device according to a manufacturing example of the present invention and an ITO-based organic light-emitting device according to a comparative example.

22 is a graph of photovoltage efficiency of an MXene-based organic light-emitting device according to a manufacturing example of the present invention and an ITO-based organic light-emitting device according to a comparative example.

23 is a light-EQE graph of an MXene-based organic light-emitting device according to a preparation example of the present invention and an ITO-based organic light-emitting device according to a comparative example.

24 is a voltage-light curve of an MXene-based organic light-emitting device according to a manufacturing example of the present invention and an ITO-based organic light-emitting device according to a comparative example.

Preparation 3
(MXene-based organic light emitting device) Comparative Example 3
(ITO-based organic light emitting device) Maximum current density 101.9 cd A ^-1 102.98 cd A ^-1 power efficiency 103.71 lm W ^-1 96.88 lm W ^-1 External quantum efficiency 28.5 ph/el% 29.12 ph/el%

As shown in FIGS. 20 to 24 and Table 1, the light emitting device in which an MXene material is applied as a transparent electrode and hole-injected containing a neutralized conductive polymer composition according to the present invention is a conventional ITO transparent electrode-based OLED device and It was confirmed that the same photochemical properties were exhibited, and the power efficiency was rather higher.

25 is an operation view of an MXene-based organic light emitting device manufactured according to Preparation Example 3 of the present invention.

As shown in FIG. 25 , the light emitting device according to the present invention can be actually driven.

Therefore, the light emitting device according to the present invention can be practically driven by using MXene material, which is cheaper than ITO, as a transparent electrode, and exhibits device performance equivalent to that of a conventional ITO-based organic light-emitting device. Alternatively, a light emitting device having the same performance can be manufactured at a low manufacturing cost.

< manufacturing example 4 : flexible MXene Manufacturing of organic light emitting device>

A flexible MXene-based organic light emitting device was manufactured in the same manner as in Preparation Example 3, except that a PET substrate was used as a substrate instead of a glass substrate.

26 is a view of a flexible MXene-based organic light emitting device manufactured on a PET substrate according to Preparation Example 4 of the present invention.

As shown in FIG. 26 , it was confirmed that the MXene material according to the present invention can be coated on a PET substrate, so that it can be manufactured as a flexible organic light emitting device.

Therefore, the light emitting device according to the present invention can be practically driven by using MXene material, which is cheaper than ITO, as a transparent electrode, and exhibits device performance equivalent to that of a conventional ITO-based organic light emitting device, and is also easy to manufacture as a flexible organic light emitting device. Therefore, it can be usefully used to replace the conventional ITO-based organic light emitting device.

On the other hand, the embodiments of the present invention disclosed in the present specification and drawings are merely presented as specific examples to aid understanding, and are not intended to limit the scope of the present invention. It will be apparent to those of ordinary skill in the art to which the present invention pertains that other modifications based on the technical spirit of the present invention can be implemented in addition to the embodiments disclosed herein.

10: substrate
20: positive electrode
30: hole injection layer
40: light emitting layer
50: cathode

Claims (20)

Board;
a first electrode positioned on the substrate;
a hole injection layer positioned on the first electrode;
a light emitting layer positioned on the hole injection layer; and
a second electrode positioned on the light emitting layer;
The first electrode is an electrode including an MXene material represented by the following Chemical Formula 1,
The hole injection layer is a conductive polymer by adding a fluorine-based material and a basic material of the following formula (2) to the conductive polymer, having a work function of 5.6 eV or more in the thin film, and neutralizing the conductive polymer composition to a pH of 4.0 to 10.0 in a dispersion or solution state. Light emitting device characterized in that.
[Formula 1]
M _{n+ 1} X _n T _x
(In Formula 1,
M is a transition metal,
X is C or N;
T _x is a -OH, -O or -F end group located on the surface,
n is an integer from 1 to 3.)
[Formula 2]

(In Formula 2,
0 < m ≤ 10,000,000, 0 ≤ n < 10,000,000, 0 ≤ a ≤ 20, 0 ≤ b ≤ 20;
A, B, A' and B' are each independently selected from the group consisting of C, Si, Ge, Sn, and Pb;
R ₁ , R ₂ , R ₃ , R ₄ , R ₁ ', R ₂ ', R ₃ ' and R ₄ ' are each independently hydrogen, halogen, nitro group, substituted or unsubstituted amino group, cyano group, substituted or unsubstituted C ₁ -C ₃₀ alkyl group, substituted or unsubstituted C ₁ -C ₃₀ heteroalkyl group, substituted or unsubstituted C ₁ -C ₃₀ alkoxy group, substituted or unsubstituted C ₁ -C ₃₀ heteroalkoxy group, a substituted or unsubstituted C ₆ -C ₃₀ aryl group, a substituted or unsubstituted C ₆ -C aryl group, a substituted or unsubstituted aryloxy-substituted C ₆ -C _30, substituted or unsubstituted C _{2 30} - C ₃₀ heteroaryl group, substituted or unsubstituted C ₂ -C ₃₀ heteroarylalkyl group, substituted or unsubstituted C ₂ -C ₃₀ heteroaryloxy group, substituted or unsubstituted C ₅ -C ₂₀ cyclo Alkyl group, substituted or unsubstituted C ₂ -C ₃₀ heterocycloalkyl group, substituted or unsubstituted C ₁ -C ₃₀ alkylester group, substituted or unsubstituted C ₁ -C ₃₀ heteroalkyl ester group, substituted or unsubstituted selected from the group consisting of a C ₆ -C ₃₀ aryl ester group and a substituted or unsubstituted C ₂ -C ₃₀ heteroaryl ester group, provided that at least one of _{R 1} , R ₂ , R ₃ , and R _{4 .} The above is an ionic group or contains an ionic group;
X and X' are each independently a simple bond, O, S, a substituted or unsubstituted C ₁ -C ₃₀ alkylene group, a substituted or unsubstituted C ₁ -C ₃₀ heteroalkylene group, a substituted or unsubstituted C ₆ - C ₃₀ arylene group, substituted or unsubstituted C ₆ -C ₃₀ arylalkylene group, substituted or unsubstituted C ₂ -C ₃₀ heteroarylene group, substituted or unsubstituted C ₂ -C ₃₀ heteroarylalkylene group , a substituted or unsubstituted C ₅ -C ₂₀ cycloalkylene group, a substituted or unsubstituted C ₅ -C ₃₀ heterocycloalkylene group, a substituted or unsubstituted C ₆ -C ₃₀ aryl ester group, and a substituted or It is selected from the group consisting of an unsubstituted C ₂ -C _{30 heteroaryl ester group,}
However, when n is 0, _{at least one of R 1} , R ₂ , R ₃ , and R ₄ is a hydrophobic functional group including a halogen element or a hydrophobic functional group.) According to claim 1,
The MXene material is Ti ₂ C, Ti ₂ N, Mo ₂ C,V ₂ C, Nb ₂ C, Ti ₃ C ₂ , Zr ₃ C ₂ , Ti ₄ N ₃ , V ₄ C ₃ , Nb ₄ C ₃ , Ta ₄ C ₃ A light emitting device, characterized in that it is selected from the group consisting of and derivatives thereof. According to claim 1,
The first electrode is a light emitting device, characterized in that it has a transmittance of 50 to 95%, and a sheet resistance of 10 to 300 ohm/sq by controlling the thickness of the thin film containing the MXene material. According to claim 1,
The MXene material is a light emitting device, characterized in that the -OH group, -O group on the surface is removed through heat treatment on the surface, and the density of -F group is increased. According to claim 1,
The conductive polymer is a copolymer including two or more different repeating units selected from among polythiophene, polyaniline, polypyrrole, polystyrene, polyethylenedioxythiophene, polyacetylene, polyphenylene, polyphenylvinylene and polycarbazole, and derivatives thereof. Or a light emitting device comprising a mixture of two or more of them. According to claim 1,
The basic material is naphtylamine (2-Naphtylamine), arylaniline (n-Allylaniline), aminobiphenyl (4-Aminobiphenyl), toluidine (o-Toluidine), aniline (Aniline), quinoline (Quinoline), dimethyl aniline (N,N,-Diethyl aniline) and pyridine (Pyridine) selected from the group consisting of, a pKa of 4 to 6 light emitting device, characterized in that the amine compound or pyridine compound. According to claim 1,
The conductive polymer composition is a light emitting device, characterized in that it comprises a PEDOT: PSS polymer, a perfluorinated ionomer (PFI) and aniline. According to claim 1,
The conductive polymer composition comprises 100 parts by weight of a conductive polymer, 100 to 200 parts by weight of a fluorine-based material, and 0.5 to 5 parts by weight of a basic material. According to claim 1,
The light emitting device is a light emitting device, characterized in that selected from the group consisting of a light emitting diode, a light emitting transistor (light-emitting transistor), a laser (laser) light emitting device and a polarized light emitting device. According to claim 1,
The light emitting device is a light emitting device, characterized in that it is a flexible light emitting device using a flexible substrate. forming a first electrode including an MXene material represented by the following Chemical Formula 1 on a substrate (S10);
forming a hole injection layer on the first electrode with a conductive polymer composition including a conductive polymer, a fluorine-based material represented by Chemical Formula 2, and a basic material (S20);
forming a light emitting layer on the hole injection layer (S30); and
and forming a second electrode on the light emitting layer (S40).
[Formula 1]
M _n+1 X _n T _x
(In Formula 1,
M is a transition metal,
X is C or N;
T _x is a -OH, -O or -F end group located on the surface,
n is an integer from 1 to 3.)
[Formula 2]

(In Formula 2,
0 < m ≤ 10,000,000, 0 ≤ n < 10,000,000, 0 ≤ a ≤ 20, 0 ≤ b ≤ 20;
A, B, A' and B' are each independently selected from the group consisting of C, Si, Ge, Sn, and Pb;
R ₁ , R ₂ , R ₃ , R ₄ , R ₁ ', R ₂ ', R ₃ ' and R ₄ ' are each independently hydrogen, halogen, nitro group, substituted or unsubstituted amino group, cyano group, substituted or unsubstituted C ₁ -C ₃₀ alkyl group, substituted or unsubstituted C ₁ -C ₃₀ heteroalkyl group, substituted or unsubstituted C ₁ -C ₃₀ alkoxy group, substituted or unsubstituted C ₁ -C ₃₀ heteroalkoxy group, a substituted or unsubstituted C ₆ -C ₃₀ aryl group, a substituted or unsubstituted C ₆ -C aryl group, a substituted or unsubstituted aryloxy-substituted C ₆ -C _30, substituted or unsubstituted C _{2 30} - C ₃₀ heteroaryl group, substituted or unsubstituted C ₂ -C ₃₀ heteroarylalkyl group, substituted or unsubstituted C ₂ -C ₃₀ heteroaryloxy group, substituted or unsubstituted C ₅ -C ₂₀ cyclo Alkyl group, substituted or unsubstituted C ₂ -C ₃₀ heterocycloalkyl group, substituted or unsubstituted C ₁ -C ₃₀ alkylester group, substituted or unsubstituted C ₁ -C ₃₀ heteroalkyl ester group, substituted or unsubstituted selected from the group consisting of a C ₆ -C ₃₀ aryl ester group and a substituted or unsubstituted C ₂ -C ₃₀ heteroaryl ester group, provided that at least one of _{R 1} , R ₂ , R ₃ , and R _{4 .} The above is an ionic group or contains an ionic group;
X and X' are each independently a simple bond, O, S, a substituted or unsubstituted C ₁ -C ₃₀ alkylene group, a substituted or unsubstituted C ₁ -C ₃₀ heteroalkylene group, a substituted or unsubstituted C ₆ - C ₃₀ arylene group, substituted or unsubstituted C ₆ -C ₃₀ arylalkylene group, substituted or unsubstituted C ₂ -C ₃₀ heteroarylene group, substituted or unsubstituted C ₂ -C ₃₀ heteroarylalkylene group , a substituted or unsubstituted C ₅ -C ₂₀ cycloalkylene group, a substituted or unsubstituted C ₅ -C ₃₀ heterocycloalkylene group, a substituted or unsubstituted C ₆ -C ₃₀ aryl ester group, and a substituted or It is selected from the group consisting of an unsubstituted C ₂ -C _{30 heteroaryl ester group,}
However, when n is 0, _{at least one of R 1} , R ₂ , R ₃ , and R ₄ is a hydrophobic functional group including a halogen element or a hydrophobic functional group.) 12. The method of claim 11,
Step S10 is a method of manufacturing a light emitting device, characterized in that the MXene thin film is formed by coating a solution in which the MXene material is dispersed on a substrate by a solution process. 13. The method of claim 12,
The MXene material is Ti ₂ C, Ti ₂ N, Mo ₂ C,V ₂ C, Nb ₂ C, Ti ₃ C ₂ , Zr ₃ C ₂ , Ti ₄ N ₃ , V ₄ C ₃ , Nb ₄ C ₃ , Ta ₄ C ₃ A method of manufacturing a light emitting device, characterized in that it is selected from the group consisting of and derivatives thereof. 13. The method of claim 12,
The solution process is a spin coating method, a spray method, a dip coating method, a bar coating method, a nozzle printing method, a slot-die coating method, a gravure printing method, a cast method, or a Langmuir-Blodgett film method (LB (Langmuir-Blodgett) )) a method of manufacturing a light emitting device, characterized in that using. 13. The method of claim 12,
The method of manufacturing a light emitting device, characterized in that the MXene thin film is formed to a thickness of 1 ~ 100 nm. 13. The method of claim 12,
The method of manufacturing a light emitting device, characterized in that the MXene thin film is heat-treated at 100 ~ 200 ℃ in order to improve the electrical properties. 12. The method of claim 11,
Step S20 is a step of forming a hole injection layer thin film by coating a solution in which 100 parts by weight of a conductive polymer, 100 to 200 parts by weight of a fluorine-based material, and 0.5 to 5 parts by weight of a basic material are mixed on the first electrode by a solution process. A method of manufacturing a light emitting device. 18. The method of claim 17,
The conductive polymer is a copolymer including two or more different repeating units selected from among polythiophene, polyaniline, polypyrrole, polystyrene, polyethylenedioxythiophene, polyacetylene, polyphenylene, polyphenylvinylene and polycarbazole, and derivatives thereof. Or a method of manufacturing a light emitting device comprising a mixture of two or more of them. 18. The method of claim 17,
The basic material is naphtylamine (2-Naphtylamine), arylaniline (n-Allylaniline), aminobiphenyl (4-Aminobiphenyl), toluidine (o-Toluidine), aniline (Aniline), quinoline (Quinoline), dimethyl aniline (N,N,-Diethyl aniline) and pyridine (Pyridine), selected from the group consisting of, pKa of 4-6 amine compound or a pyridine compound, characterized in that the manufacturing method of the light emitting device. 18. The method of claim 17,
The conductive polymer is a PEDOT:PSS polymer,
The fluorine-based material is a perfluorinated ionomer (PFI),
The method of manufacturing a light emitting device, characterized in that the basic material is aniline.

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