KR102515818B1 - Organic compounds, lighe emitting diode and light emitting device having the compounds - Google Patents

Abstract

The present invention has an amine core substituted with three aromatic rings, some of the three aromatic rings are substituted with functional groups capable of solution processing, and other aromatic rings are substituted with heteroaromatic functional groups. It relates to light emitting diodes and light emitting devices applied to By using the organic compound according to the present invention in the light emitting layer, a HOMO energy barrier between the light emitting layer and another adjacent light emitting layer can be eliminated. In addition, when the light emitting layer is formed by using the organic compound of the present invention in combination with the light emitting particles, the interface characteristics between the light emitting layer and adjacent layers are improved, and the morphology characteristics of the light emitting diode are improved. By applying the organic compound according to the present invention, since holes and electrons can be moved and injected in a balanced manner into the light emitting material layer, light emitting efficiency is improved and light emitting diodes and light emitting devices capable of low-voltage driving can be implemented and manufactured. can

Description

Organic compounds, light emitting diodes and light emitting devices including the same

The present invention relates to an organic compound, and more particularly, to an organic compound capable of a solution process, and a light emitting diode and a light emitting device including the organic compound with improved light emitting efficiency.

Among flat panel display devices, an organic light emitting diode (OLED) display device and a quantum dot light emitting diode (QLED) display device can have a thin structure and consume less power. (LCD) device) is attracting attention as a next-generation display device.

However, when the current density of the light emitting diode is increased or the driving voltage is increased in order to increase the light emitting luminance in the organic light emitting diode display device, the lifetime of the light emitting diode is shortened due to deterioration such as decomposition of the organic light emitting material used in the organic light emitting diode. There is a problem with shortening. In particular, OLED is ITU-R Recommendation BT. 2020 (Rec. 2020 or Bt. 2020) has not been able to achieve the high level of color gamut required.

Recently, efforts have been made to use quantum dots (QDs) in display devices. Quantum dots are inorganic particles that emit light as electrons in an unstable state descend from a conduction band to a valence band. Quantum dots generate strong fluorescence because they have a very high extinction coefficient and excellent quantum yield among inorganic particles. In addition, since the emission wavelength is changed according to the size of the quantum dots, by adjusting the size of the quantum dots, light in the entire visible light range can be obtained, so that various colors can be implemented. In other words, when quantum dots are used as the light emitting material layer (EML), the color purity of individual pixels can be increased, and white light composed of red (R), blue (B), and green (G) emission of high purity can be realized. . 2020 standards are achievable.

Accordingly, a quantum dot light emitting diode (QLED) is being developed using quantum dots. FIG. 1 is a schematic cross-sectional view of a general quantum dot light emitting diode, and FIG. 2 is a bandgap energy diagram in a typical quantum dot light emitting diode. is shown 1 and 2, a typical quantum dot light emitting diode 10 includes an anode and a cathode facing each other, a quantum dot emitting material layer (EML) positioned between the anode and the cathode, and the anode and the emitting material layer. A hole injection layer (HIL) and a hole transport layer (HTL) located between the (EML), and an electron transport layer (ETL) located between the cathode and the light emitting material layer (EML) and an electron injection layer (EIL).

In the quantum dot light emitting diode 10, when charge carriers are injected into a light emitting layer formed between an electron injection electrode (cathode) and a hole injection electrode (anode), electrons and holes form pairs and emit light while disappearing. am. In order to implement light emission, the hole injection layer (HIL) and the hole transport layer (HTL) inject and transfer holes, which are positive charge carriers, from the anode to the light emitting material layer (EML), and the electron injection layer (EIL) and the electron transport layer (ETL) Injects and transfers electrons, which are negative charge carriers, from the silver cathode to the light emitting material layer (EML). Holes and electrons injected from the anode and cathode meet in the light emitting material layer (EML) to form excitons. By this energy, the light emitting material included in the light emitting material layer (EML) enters an excited state. Energy transition occurs in the light emitting material from the excited state to the ground state, and the generated energy is emitted as light. to emit light

In order to inject and transfer holes and electrons into the light emitting material layer (EML), each layer must be made of a material having an appropriate bandgap energy. For example, the hole injection layer (HIL) is made of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), and the hole transport layer (HTL) is poly(4-butylphenyl-diphenyl-amine) (Poly-TPD) , the electron transport layer (ETL) may be made of ZnO, and the electron injection layer (EIL) may be made of aluminum.

The light emitting material layer (EML) is made of nano-sized quantum dots (QD), for example, after applying on the hole transport layer (HTL) through a process using a solution containing quantum dots (QD) in a solvent, volatilizes the solvent. By doing so, a light emitting material layer (EML) is formed. As shown in FIG. 1, since the light emitting material layer (EML) finally formed by volatilizing the solvent is composed of only nano-sized quantum dots (QDs), a layer positioned adjacent thereto, for example, a hole transport layer (HTL) And the interface between the electron transport layer (ETL) is not formed smoothly and has a rough cross-sectional shape. As the interface between the light emitting layers becomes rough, overall morphology characteristics of the light emitting diode 10 deteriorate, and holes and electrons are not uniformly injected into the light emitting material layer EML over the entire area of the light emitting diode 10 .

In addition, as shown in FIG. 2, compared to the highest occupied molecular orbital (HOMO) energy level of the hole transport material constituting the hole transport layer (HTL), the quantum dots constituting the light emitting material layer (EML) A valence band energy level corresponding to the HOMO energy level of an inorganic light emitting material such as the like is very low (deep). In addition, the conduction band energy level corresponding to the LUMO energy level of the inorganic light emitting material constituting the light emitting material layer (EML) is higher than the lowest unoccupied molecular orbital (LUMO) energy level of the organic light emitting material ( high). Therefore, when holes are transported from the hole transport layer (HTL) to the light emitting material layer (EML) and when electrons are transported from the electron transport layer (ETL) to the light emitting material layer (EML), light emitting constituting the light emitting material layer (EML) An energy barrier is formed due to the difference between the energy level of the material and the energy level of the adjacent charge transport layer.

However, compared to the difference (ΔG _L ) between the LUMO energy level of the electron transport layer (ETL) and the LUMO energy level of the light emitting material layer (EML), the HOMO energy level of the hole transport layer (HTL) and the HOMO energy of the light emitting material layer (EML) The difference in levels (ΔG _H ) is much larger (ΔG _H > ΔG _L ). For example, the HOMO energy level of hole transport materials such as poly-TPD used in the hole transport layer (HTL) is around -5.0 eV, whereas the valence band energy level corresponding to the HOMO energy level of the shell constituting the inorganic light emitting material is approximately -7.0 eV. Therefore, compared to the movement and injection of electrons into the light emitting material layer (EML), since the movement and injection of holes into the light emitting material layer (EML) is delayed, positively charged holes and negatively charged electrons are transferred to the light emitting material layer (EML). cannot be injected in a balanced way.

Holes and electrons are not uniformly injected over the entire area of the light emitting material layer (EML) due to the deterioration of overall morphological characteristics of the light emitting diode 10, so holes and electrons do not emit light and are lost. In addition, as electrons are injected into the light emitting material layer (EML) in excess compared to holes due to the difference in energy barrier, a significant portion of the excessively injected electrons recombine with the holes to form excitons and disappear. In addition, as electrons are injected into the light emitting material layer EML more quickly than holes, holes and electrons are not recombinated in the light emitting material constituting the light emitting material layer EML, and the light emitting material layer EML and the hole transport layer ( HTL) recombines at the interface. Accordingly, not only does the light emitting efficiency of the light emitting diode decrease, but also a high driving voltage is required to realize desired light emission, which causes an increase in power consumption.

An object of the present invention is to provide an organic compound in which charges such as holes and electrons can be injected into a light emitting material layer in a balanced manner by improving the speed of hole movement into the light emitting material layer, and a light emitting diode and a light emitting device using the same. .

Another object of the present invention is to provide an organic compound capable of solution processing and functioning as a matrix, and a light emitting diode and a light emitting device having excellent overall morphological characteristics by applying the organic compound and capable of uniformly injecting electric charges over the entire area. that you want to provide.

Another object of the present invention is to provide an organic compound capable of improving light emitting efficiency and realizing low-voltage driving, and a light emitting diode and a light emitting device using the same.

According to one aspect of the present invention, the present invention has an amine moiety substituted with three aromatic rings having excellent hole transfer properties as a core, some of the three aromatic rings are substituted with functional groups capable of solution processing, and other aromatic rings The ring provides an organic compound substituted with a condensed heteroaromatic functional group having at least two heteroatoms.

In another aspect of the present invention, the present invention provides a light emitting diode in which the organic compound is used in a light emitting layer.

In an exemplary embodiment, the organic compound may be used as a host of the light emitting material layer.

According to another aspect of the present invention, the present invention provides a light emitting device including a substrate, the above-described light emitting diode located on the substrate, and a driving element located between the substrate and the light emitting diode and connected to the light emitting diode, an example To provide a light emitting display device.

The organic compound of the present invention comprises an amine core moiety substituted with three aromatic rings, a solution processable functional group moiety connected to a portion of the three aromatic rings, and a condensed heteroaromatic functional group connected to the other portion of the three aromatic rings. made up of moieties

Not only does it have excellent hole transfer characteristics due to the amine core moiety substituted with three aromatic rings, but also has a high triplet energy level (E _T ) due to having a condensed heteroaromatic functional group moiety, and excellent thermal stability, Electron transfer properties are also excellent, and solution processing is possible.

That is, the organic compound according to the present invention can be applied to the light emitting layer of a light emitting diode as a bipolar compound having excellent transport and coupling characteristics for both holes and electrons.

In particular, when used in combination with inorganic light emitting materials such as quantum dots and quantum rods, it is used as a matrix for uniformly dispersing the inorganic light emitting material, so that an interface with an adjacent light emitting layer can be formed smoothly. Accordingly, while the light emitting diode has a desired shape, morphology characteristics may be improved.

In addition, the organic compound according to the present invention has a relatively high HOMO energy level. Therefore, when used in the light emitting material layer in combination with the organic compound according to the present invention and an inorganic light emitting material having a very low valence band energy level, the difference in HOMO energy level between the light emitting material layer and the hole transport layer can be reduced. can

By applying the organic compound according to the present invention to the light emitting layer, holes and electrons are injected in a balanced manner into the light emitting material layer, so that holes and electrons are not lost and excitons can be effectively formed to contribute to light emission. Accordingly, it is possible to implement and manufacture a light emitting diode and a light emitting device capable of improving light emitting efficiency and reducing power consumption due to low-voltage driving.

1 is a schematic cross-sectional view of a conventional light emitting diode.
2 is a diagram schematically illustrating energy levels of materials constituting an electrode constituting a conventional light emitting diode and a light emitting layer positioned between the electrodes.
3 is a schematic cross-sectional view of a light emitting diode having a normal structure, according to the first exemplary embodiment of the present invention.
4 is a diagram schematically illustrating energy levels of materials constituting an electrode and a light emitting layer constituting a light emitting diode according to the first exemplary embodiment of the present invention.
5 is a schematic cross-sectional view of a light emitting diode having an inverted structure according to a second exemplary embodiment of the present invention.
6 is a diagram schematically showing energy levels of materials constituting an electrode and a light emitting layer constituting a light emitting diode according to a second exemplary embodiment of the present invention.
7 is a schematic cross-sectional view of a light emitting diode display device as an example of a light emitting device to which a light emitting diode according to an exemplary embodiment of the present invention is applied.
8 is a graph showing the results of measuring the voltage-current density of a light emitting diode to which an organic compound synthesized according to an exemplary embodiment of the present invention is applied to a light emitting layer.
9 is a graph showing the results of measuring the voltage-luminance of a light emitting diode to which an organic compound synthesized according to an exemplary embodiment of the present invention is applied to a light emitting layer.

Hereinafter, the present invention will be described with reference to the accompanying drawings when necessary.

A compound used as a charge transport material in a light emitting diode needs to have excellent charge mobility and must be able to inject charges into the light emitting material layer in a balanced manner. An organic compound according to one aspect of the present invention may satisfy these characteristics and may be represented by Formula 1 below.

Formula 1

(In Formula 1, R ₁ and R ₂ are each independently an unsubstituted or substituted C ₁ ~ C ₂₀ linear or branched alkyl group, an unsubstituted or substituted C ₂ ~ C ₂₀ linear or branched alkenyl group, and an unsubstituted or substituted C ₁ ~ C ₂₀ Selected from the group consisting of alkoxy groups; R ₃ is a C ₈ ~ C ₃₀ fused heteroaryl group having 2 or more heteroatoms, a C ₈ ~C ₃₀ fused heteroaralkyl group having 2 or more heteroatoms, 2 Selected from the group consisting of a C ₈ ~ C ₃₀ fused heteroaryloxy group having at least two heteroatoms and a C ₈ ~C ₃₀ fused heteroaryl amine group having at least 2 heteroatoms; Ar ₁ to Ar ₃ are each independently substituted unsubstituted or substituted C ₅ ~C ₃₀ homoaryl group, unsubstituted or substituted C ₄ ~C ₃₀ heteroaryl group, unsubstituted or substituted C ₅ ~C ₃₀ homoaralkyl group, unsubstituted or substituted C ₄ ~C ₃₀ hetero aralkyl group, unsubstituted or substituted C ₅ ~ C ₃₀ homo araloxy group and unsubstituted or substituted C ₄ ~ C ₃₀ selected from the group consisting of hetero araloxy group)

In the present specification, 'unsubstituted' or 'unsubstituted' means that a hydrogen atom is substituted, and in this case, the hydrogen atom includes light hydrogen, heavy hydrogen, and tritium.

In the present specification, the substituent in 'substituted' is, for example, a C ₁ ~ C ₂₀ alkyl group unsubstituted or substituted with a halogen atom, a cyano group, and/or a nitro group, an unsubstituted or substituted with a halogen atom, a cyano group, and/or a nitro group. C ₁ ~C ₂₀ alkoxy group, halogen atom, cyano group, alkyl halide group such as -CF ₃ , hydroxy group unsubstituted or substituted with a halogen atom, cyano group and/or nitro group, carboxy group, carbonyl group, amine group , C ₁ ~C ₁₀ alkyl substituted amine group, C ₅ ~C ₃₀ aryl substituted amine group, C ₄ ~C ₃₀ heteroaryl substituted amine group, nitro group, hydrazyl group, sulfonic acid group, C ₁ ~C ₂₀ Alkyl silyl group, C ₁ ~C ₂₀ Alkoxy silyl group, C ₃ ~C ₃₀ Cycloalkyl silyl group, C ₅ ~C ₃₀ Aryl silyl group, C ₄ ~C ₃₀ Heteroaryl silyl group, C ₅ ~C ₃₀ Aryl group , C ₄ ~ C ₃₀ heteroaryl group, C ₅ ~ C ₃₀ homo aralkyl group, C ₄ ~ C ₃₀ hetero aralkyl group, C ₅ ~ C ₃₀ homo aralkoxy group or C ₄ ~ C ₃₀ hetero aralkoxy group, and the like. However, the present invention is not limited thereto.

In the present specification, the term 'hetero' used in 'heteroaromatic ring', 'heterocycloalkylene group', 'heteroaryl group', 'heteroaralkyl group', 'heteroaraloxyl group', 'heteroarylamine group', etc. It means that one or more of the carbon atoms constituting the aromatic or alicyclic ring, for example, 1 to 5 carbon atoms are substituted with one or more heteroatoms selected from the group consisting of N, O, S, and combinations thereof. do.

As shown in Chemical Formula 1, since the organic compound according to the present invention has an amine core moiety linked to three aromatic functional groups, it has excellent hole transfer properties that transfer holes while easily binding to holes. In addition, R ₁ and/or R ₂ functional groups are soluble moieties, and thus, the organic compound according to the present invention has an advantage of being layered through a solution process.

In one exemplary embodiment, R ₃ in Formula 1 is a substituted or unsubstituted C ₈ ~ C ₃₀ fused heteroaryl group having two or more nitrogen atoms, or a substituted or unsubstituted C ₈ ~ C ₃₀ fused hetero aralkyl group. , a substituted or unsubstituted C ₈ ~ C ₃₀ condensed heteroaryloxy group or a substituted or unsubstituted C ₈ ~ C ₃₀ condensed heteroaryl amine group. More specifically, in Formula 1, R ₃ is an unsubstituted or substituted indolyl group, phthalazinyl group, quinoxalinyl group, cinolinyl group, quinazolinyl group, benzoindolyl group, benzophthalazinyl group, benzoquinoxalinyl group, Benzocinolinyl group, benzoquinazolinyl group, benzoazepinyl group, dibenzoindolyl group, dibenzophthalazinyl group, dibenzoquinoxalinyl group, dibenzocinolinyl group, dibenzoquinazolinyl group, dibenzoazepinyl group, It may be selected from the group consisting of an indolopyridyl group, an indolocarbazolyl group, a carvolyl group, and a phenanthrolinyl group, but the present invention is not limited thereto. As such, when R ₃ is a condensed heteroaromatic substituent containing two or more nitrogen atoms, the moiety represented by R ₃ combines with electrons to transfer electrons, resulting in electron transfer characteristics. In this case, the organic compound according to the present invention may be a bipolar compound having both hole transfer characteristics and electron transfer characteristics.

Meanwhile, in one non-limiting embodiment, in Formula 1, Ar ₁ to Ar ₃ are each independently an unsubstituted or substituted phenyl group, a biphenyl group, a terphenyl group, a tetraphenyl group, a naphthyl group, an anthracenyl group, an indenyl group, uncondensed or fused homoaromatic rings such as phenalenyl, phenanthrenyl, azulenyl, pyrenyl, fluorenyl, tetracenyl, indacenyl or spiro fluorenyl, and/or Pyrrolyl group, pyridinyl group, pyrimidinyl group, pyrazinyl group, pyridazinyl group, triazinyl group, tetrazinyl group, imidazolyl group, pyrazolyl group, indolyl group, carbazolyl group, benzocarbazolyl group, dibenzo Carbazolyl group, indolocarbazolyl group, indenocarbazolyl group, benzofuranocarbazolyl group, benzothienocarbazolyl group, quinolinyl group, isoquinolinyl group, phthalazinyl group, quinoxalinyl group, cynoli Nyl group, quinazolinyl group, phthalazinyl group, quinoxalinyl group, cynolinyl group, quinazolinyl group, benzoquinolinyl group, benzoisoquinolinyl group, benzoquinazolinyl group, benzoquinoxalinyl group, acridinyl group, phenanthroly Nyl group, furanyl group, pyranyl group, oxazinyl group, oxazolyl group, oxadiazolyl group, triazolyl group, dioxynyl group, benzofuranyl group, dibenzofuranyl group, thiopyranyl group, thiazinyl group, thiophenyl group or a non-condensed or condensed heteroaromatic ring such as an N-substituted spiro fluorenyl group.

For example, in Formula 1, Ar ₁ to AR ₃ may be, in addition to R ₁ to R ₃ , a phenyl group, a biphenyl group, a terphenyl group, substituted with at least one functional group selected from a halogen atom such as fluorine, a nitro group, and/or a cyano group; A benzothiophenyl group substituted with at least one functional group selected from a homoaryl group such as naphthyl group, anthracenyl group, fluorenyl group or spirofluorenyl group and/or a halogen atom such as fluorine, a nitro group and/or a cyano group , dibenzothiophenyl group, benzofuranyl group, dibenzofuranyl group, pyrrolyl group, pyridinyl group, pyrimidinyl group, pyrazinyl group, pyridazinyl group, triazinyl group, tetrazinyl group, imidazolyl group, pyrazole diary, indole group, carbazolyl group, benzocarbazolyl group, dibenzocarbazolyl group, indolocarbazolyl group, indenocarbazolyl group, benzofuranocarbazolyl group, benzothienocarbazolyl group, quinolinyl group, Isoquinolinyl group, phthalazinyl group, quinoxalinyl group, cinolinyl group, quinazolinyl group, phthalazinyl group, quinoxalinyl group, cinolinyl group, quinazolinyl group, benzoquinolinyl group, benzoisoquinolinyl group, It may be a heteroaryl group such as a benzoquinazolinyl group or a benzoquinoxalinyl group.

In this case, when the number of aromatic rings constituting Ar ₁ to Ar ₃ increases, the conjugated structure in the entire organic compound becomes excessively long, and thus the band gap of the organic compound may be excessively reduced. Therefore, the number of aromatic rings constituting Ar ₁ to Ar ₃ is preferably 1 to 2, more preferably 1. In addition, with respect to hole injection and transfer characteristics, Ar ₁ to Ar ₃ may each be a 5-membered ring or a 7-membered ring, particularly a 6-membered ring (6 -membered ring) may be desirable. For example, Ar ₁ to Ar ₃ are each independently a substituted or unsubstituted phenyl group, a biphenyl group, a naphthyl group, a biphenyl group, a pyrrole group, an imidazole group, a pyrazole group, a pyridinyl group, a pyrazinyl group, or a pyrimidinyl group. , It may be a pyridazinyl group, a furanyl group, or a thiophenyl group.

The organic compound represented by Chemical Formula 1 has an amine core moiety substituted with three aromatic functional groups, some of the three aromatic functional groups are soluble functional groups, and others are substituted with condensed heteroaromatic functional groups. Accordingly, the organic compound represented by Chemical Formula 1 not only has excellent charge transfer characteristics, but also has high thermal stability and triplet energy level (E _T ) and can be subjected to a solution process.

In addition, since it has a relatively high HOMO energy level, when the light emitting material layer is formed in combination with an inorganic light emitting material having a low HOMO energy level (valence band energy level), the HOMO energy level of the light emitting material layer is increased, particularly A HOMO energy band gap between the hole transfer layer and the light emitting material layer may be reduced. In addition, when a solution process is applied together with the inorganic light emitting material, the organic compound of Chemical Formula 1 may function as a matrix for dispersing the inorganic light emitting material. Since the interface between the light emitting material layer and the layer adjacent to the light emitting material layer has a smooth cross section, morphology characteristics of the light emitting diode may be improved.

A HOMO energy bandgap between the light emitting material layer and the hole transfer layer is reduced and morphological characteristics of the light emitting diode are improved, so that holes and electrons can be injected into the light emitting material layer in a balanced manner over the entire area. When the organic compound of Chemical Formula 1 is applied to a light emitting diode, holes and electrons injected from the anode and cathode are not lost and are injected into the light emitting material layer to form effective excitons, and the charge transfer layer adjacent to the light emitting material layer Light emission can be realized not at the interface but in the region where the light emitting material is located. Accordingly, a light emitting diode having improved light emitting efficiency and capable of being driven at a low voltage can be manufactured using the organic compound of Chemical Formula 1.

According to one exemplary embodiment, in the organic compound represented by Chemical Formula 1, the aromatic linking group bonded to amine may be a phenyl group or a naphthyl group. These organic compounds have the advantage of greatly improving hole transfer properties. For example, the organic compound represented by Chemical Formula 1 may include an organic compound represented by Chemical Formula 2 below.

Formula 2

(In Formula 1, R ₁ to R ₃ are the same as defined in Formula 1; Ar ₄ to Ar ₆ are each independently a phenyl group or a naphthyl group)

Looking more specifically, the organic compound that can be used in the hole transfer layer of the light emitting diode may include any one organic compound represented by Chemical Formula 3 below.

Formula 3

The organic compound represented by Formula 2 or Formula 3 has an amine core moiety substituted with a phenyl or naphthyl group having excellent hole transfer properties, a moiety having soluble properties, and a condensed heteroaromatic moiety having excellent electron transfer properties. there is. Applying the organic compound represented by Formula 2 or Formula 3 to the light emitting layer of the light emitting diode, for example, the light emitting material layer, to improve the morphology characteristics of the light emitting diode and to reduce the HOMO energy band gap between the light emitting material layer and the adjacent hole transfer layer. can Accordingly, a light emitting diode having excellent light emitting efficiency and capable of being driven at a low voltage can be implemented.

Subsequently, a light emitting diode comprising an organic compound according to the present invention will be described. 3 is a schematic cross-sectional view of a light emitting diode having a normal structure according to the first exemplary embodiment of the present invention, and FIG. 4 is a cross-sectional view showing a light emitting diode according to the first exemplary embodiment of the present invention. It is a diagram schematically showing the bandgap energy of materials constituting the constituting electrode and the light emitting layer.

As shown in FIG. 3, a light emitting diode 100 according to an exemplary embodiment of the present invention includes a first electrode 110, a second electrode 120 facing the first electrode, and a first electrode 110. ) and the second electrode 120, and includes a light emitting layer 130 including an emitting material layer (EML, 150). For example, the light emitting layer 130 includes a first charge transfer layer 140 positioned between the first electrode 110 and the light emitting material layer 150 and between the light emitting material layer 150 and the second electrode 120. A second charge transfer layer 160 may be further included.

In the first embodiment of the present invention, the first electrode 110 may be an anode such as a hole injection electrode. The first electrode 110 may be formed on a substrate (not shown in FIG. 2) which may be glass or polymer. For example, the first electrode 10 may be indium-tin-oxide (ITO), indium-zinc-oxide (IZO), or indium-tin-zinc-oxide (indium-tin-oxide). tin-zinc oxide (ITZO), indium-copper-oxide (ICO), tin oxide (SnO ₂ ), indium oxide (In ₂ O ₃ ), cadmium:zinc oxide (Cd:ZnO), fluorine Doped or undoped, including: tin oxide (F:SnO ₂ ), indium:tin oxide (In:SnO ₂ ), gallium:tin oxide (Ga:SnO ₂ ) and aluminum:zinc oxide (Al:ZnO; AZO). It may be a non-metal oxide. Optionally, the first electrode 110 may include nickel (Ni), platinum (Pt), gold (Au), silver (Ag), iridium (Ir) or carbon nanotube (CNT) in addition to the aforementioned metal oxide. It may be made of a metal material or a non-metal material including.

In the first embodiment of the present invention, the second electrode 120 may be a cathode such as an electron injection electrode. For example, the second electrode 120 may be Ca, Ba, Ca/Al, LiF/Ca, LiF/Al, BaF ₂ /Al, CsF/Al, CaCO ₃ /Al, BaF ₂ /Ca/Al, Al, Mg, It may consist of Au:Mg or Ag:Mg. For example, the first electrode 110 and the second electrode 120 may be stacked to a thickness of 30 to 300 nm.

In one exemplary embodiment, in the case of a bottom emission type light emitting diode, the first electrode 110 may be made of a transparent conductive metal such as ITO, IZO, ITZO, or AZO, and the second electrode 120 is Ca , Ba, Ca/Al, LiF/Ca, LiF/Al, BaF ₂ /Al, Al, Mg, Ag:Mg alloy, etc. may be used.

The first charge transfer layer 140 that can form the light emitting layer 130 is positioned between the first electrode 110 and the light emitting material layer 150 . In the first embodiment of the present invention, the first charge transfer layer 140 may be a hole transfer layer supplying holes to the light emitting material layer 150 . For example, the first charge transfer layer 140 is a hole injection layer (HIL, 142) positioned adjacent to the first electrode 110 between the first electrode 110 and the light emitting material layer 150. and a hole transport layer (HTL, 144) positioned adjacent to the light emitting material layer 150 between the first electrode 110 and the light emitting material layer 150.

The hole injection layer 142 facilitates hole injection from the first electrode 110 into the light emitting material layer 150 . For example, the hole injection layer 142 is poly (ethylenedioxythiophene): polystyrenesulfonate (PEDOT: PSS), tetrafluoro-tetracyano-quinodimethane (tetrafluoro-tetracyano- 4,4',4"-tris(diphenylamino)triphenylamine (4,4',4"-tris(diphenylamino)triphenylamine; TDATA) doped with quinodimethane; F4-TCNQ); For example, p-doped phthalocyanine such as F4-TCNQ doped zinc phthalocyanine (ZnPc), F4-TCNQ doped N,N'-diphenyl-N,N'-bis(1-naphthyl ) -1,1'-biphenyl-4,4"-diamine (N,N'-diphenyl-N,N'-bis(1-naphtyl)-1,1'-biphenyl-4,4"-diamine; α-NPD), hexaazatriphenylene-hexanitrile (HAT-CN), and combinations thereof, but the present invention is not limited thereto. For example, a dopant such as F4-TCNQ may be doped in an amount of 1 to 30% by weight with respect to the host.

In another exemplary embodiment, the hole injection layer 142 may be formed of organic compounds represented by Chemical Formulas 1 to 3. The hole injection layer 142 may be omitted depending on the structure and shape of the light emitting diode 100 .

The hole transport layer 144 transfers holes from the first electrode 110 to the light emitting material layer 150 . In the drawings, the first charge transfer layer 140 is divided into a hole injection layer 142 and a hole transport layer 144, but the first charge transfer layer 140 may be formed of a single layer. For example, the hole injection layer 142 may be omitted and the first charge transfer layer 140 may include only the hole transport layer 144 .

The hole transport layer 144 transfers holes from the first electrode 110 to the light emitting material layer 150 . The hole transport layer 144 may be made of an inorganic or organic material. For example, when the hole transport layer 144 is made of an organic material, the hole transport layer 144 is 4,4'-N, N'-dicarbazolyl-biphenyl (4,4'-N, N'-dicarbazolyl-biphenyl ; CBP), N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4"-diamine (N,N'-diphenyl-N,N '-bis(1-naphtyl)-1,1'-biphenyl-4,4"-diamine; α-NPD), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1 ,1'-biphenyl)-4,4'-diamine (N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine; TPD), N, N'-bis (3-methylphenyl) -N, N'-bis (phenyl) -spiro (N, N'-bis (3-methylphenyl) -N, N'-bis (phenyl) - spiro; spiro-TPD), N,N'-di(4-(N,N'-diphenyl-amino)phenyl-N,N'-diphenylbenzidine (N,N'-di(4-(N, N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine; DNTPD), 4,4',4"-tris(N-carbazolyl-triphenylamine(4,4',4"-tris(N Arylamines such as -carbazolyl)-triphenylamine; TCTA), polyaniline, polypyrrole, poly(phenylenevinylene), copper phthalocyanine, aromatic tertiary amines amine) or polynuclear aromatic tertiary amine, 4,4'-bis(p-carbazolyl)-1,1'-biphenyl compound (4,4'-bis(p-carbazolyl)-1 ,1'-biphenyl compound), N,N,N',N'-tetraarylbenzidine (N,N,N',N'-tetraarylbenzidine), PEDOT:PSS and its derivatives, poly-N-vinylcarbazole ( Poly(N-vinylcarbazole) ; PVK) and its derivatives, poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene](poly[2-methoxy-5-(2-ethylhexyloxy)-1, 4-phenylenevinylene]; MEH-PPV) or poly[2-methoxy-5-(3',7'-dimethyloctyloxy)1,4-phenylenevinylene](poly[2-methoxy-5-(3 ',7'-dimethyloctyloxy)-1,4-phenylenevinylene]; poly(para)phenylenevinylene and its derivatives such as MOMO-PPV), polymethacrylate and its derivatives, poly(9,9- octylfluorene) (poly(9,9-octylfluorene) and its derivatives, poly(spiro-fluorene) and its derivatives, N,N'-di(naphthalene-l-yl )-N,N'-diphenyl-benzidine (N,N'-di(naphthalene-l-yl)-N,N'-diphenyl-benzidine; NPB), tris(3-methylphenylphenylamino)-triphenylamine (tris(3-methylphenylphenylamino)-triphenylamine; m-MTDATA), poly(9,9'-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec -Butylphenyl)diphenylamine (poly(9,9'-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine; TFB), poly(4 -Butylphenyl-diphenylamine) (Poly (4-butylphenyl-dipnehyl amine); poly-TPD), spiro-NPB (spiro-NPB), and may be made of an organic material selected from the group consisting of combinations thereof.

When the hole transport layer 144 is made of an inorganic material, the hole transport layer 144 is a metal oxide such as NiO, MoO ₃ , Cr ₂ O ₃ , Bi ₂ O ₃ or p-type ZnO, copper thiocyanate (CuSCN), Mo ₂ It may be made of an inorganic material selected from the group consisting of S, non-oxidizing equivalents such as p-type GaN, or combinations thereof.

In one exemplary embodiment, the hole transport layer 144 may use an organic material having a triamine moiety having excellent hole mobility. For example, the host of the hole transport layer 144 may include any one organic material represented by Chemical Formulas 4 to 6 below.

formula 4

Formula 5

formula 6

(In Formulas 4 to 6, R ₁₁ to R ₁₄ are each independently an unsubstituted or substituted C ₁ ~ C ₂₀ linear or branched alkyl group, an unsubstituted or substituted C ₁ ~ C ₂₀ alkoxy group, an unsubstituted or substituted C ₅ ~ C ₃₀ homoaryl group or unsubstituted or substituted C ₄ ~ C ₃₀ heteroaryl group; a and b are each an integer from 1 to 4; n is an integer of 1 or more)

In an exemplary embodiment, R ₁₁ to R ₁₄ in Formulas 4 to 6 are each independently an unsubstituted or substituted C1 to C20 straight-chain or branched-chain alkyl group. For example, organic compounds represented by Formulas 4 to 6 are poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (Poly[N,N'-bis( 4-butylphenyl)-N,N'-bis(phenyl)-benzidine]; poly-TPD, p-TPD), poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-( 4,4'-(N-(4-sec-butylphenyl)diphenylamine))]((poly[(9,9-dioctylflorenyl-2,7-diyl)-co-(4,4'-(N -(4-sec-butylphenyl)diphenylamine))];TFB), poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(p- Butylphenyl)diphenylamine))]((poly[(9,9-dioctylflorenyl-2,7-diyl)-co-(4,4'-(N-(p-butylphenyl)diphenylamine))]), poly [bis(4-phenyl)(2,4,6-trimethylphenyl)amine](poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]; PTAA), N,N'-bis( 3-methylphenyl) -N, N'-bis (phenyl) benzidine (N, N'-Bis (3-methylphenyl) -N, N'-bis (phenyl) benzidine; TPD), N, N'-bis (4 -Methylphenyl)-N,N'-bis(phenyl)benzidine (N,N'-Bis(4-methylphenyl)-N,N'-bis(phenyl)benzidine), N ¹ ,N ⁴ -diphenyl- N ¹ ,N ⁴ -di-m-tolylbenzene-1,4-diamine (N ¹ ,N ⁴ -diphenyl- N ¹ ,N ⁴ -di-m-tolylbenzene-1,4-diamine; TTP), N,N, N', N'-tetra (3-methylphenyl) -3,3'-dimethylbenzidine (N, N, N', N'-tetra (3-methylphenyl) 3,3'-dimethylbenzidien; HMTPD), di-[ 4-(N,N'-di-p-tolyl-amino)-phenyl]cyclohexane (di-[4-(N,N'-di-p-tolyl-amion)-phenyl]cyclohexane; TAPC), N4 ,N4'-bis(4-(6- ((3-ethyloxen-3-yl)methoxy)hexyne)phenyl)-N4,N4'-diphenylbiphenyl-4,4'-diamine (N4,N4'-Bis(4-(6-(( 3-ethyloxetan-3-yl)methoxy)hexyl)phenyl)-N4,N4'-diphenylbiphenyl-4,4'-diamine; OTPD), 4,4', 4 "-tris (N, N-phenyl-3-methylphenylamino) triphenylamine (4,4', 4''-tris (N, N-phenyl-3-methylphenylamino) triphenylamine ), etc., but

The present invention is not limited thereto.

In another exemplary embodiment, the hole transport layer 144 may include organic compounds represented by Chemical Formulas 1 to 3 above.

For example, the first charge transfer layer 140 including the hole injection layer 142 and the hole transport layer 144 may be formed by a vacuum vapor deposition process, a vacuum deposition process including a sputtering method, spin coating, or drop coating. (drop coating), dip coating (dip coating), spray coating (spray coating), roll coating (roll coating), flow coating (flow coating) as well as solution processes such as casting process, screen printing or inkjet printing method It can be used alone or in combination. For example, the thickness of the hole injection layer 142 and the hole transport layer 144 may be 10 nm to 200 nm, preferably 10 nm to 100 nm, but the present invention is not limited thereto.

Meanwhile, the light emitting material layer 150 may be formed of inorganic light emitting particles. When the light emitting material layer 150 is made of inorganic light emitting particles, the inorganic light emitting particles may be made of nano inorganic light emitting particles such as quantum dots (QDs) or quantum rods (QR).

Quantum dots or quantum rods are inorganic particles that emit light as electrons in an unstable state descend from a conduction band to a valence band. These nano-inorganic light-emitting particles have a very high extinction coefficient and excellent quantum yield among inorganic particles, so they generate strong fluorescence. In addition, since the emission wavelength is changed according to the size of the nano-inorganic light-emitting particles, adjusting the size of the nano-inorganic light-emitting particles can obtain light in the entire range of visible light, so that various colors can be implemented. That is, when nano-inorganic light-emitting particles such as quantum dots or quantum rods are used as the light-emitting material of the light-emitting material layer 150, not only can the color purity of individual pixels be increased, but also high-purity red (R), green (G), It is possible to implement white light composed of blue (B) light emission.

In one exemplary embodiment, quantum dots or quantum rods may have a unitary structure. In another exemplary embodiment, quantum dots or quantum rods may have a core/shell heterogeneous structure. At this time, the shell may be composed of one shell or may be composed of multiple shells.

The degree of growth, crystal structure, etc. of these nano-inorganic light-emitting particles can be controlled according to the reactivity and injection rate of the reactive precursor constituting the core and/or the shell, the type of ligand, and the reaction temperature. Light emission in various wavelength ranges can be induced.

For example, a quantum dot or quantum rod may have a core component that emits light at the center and a heterologous structure surrounded by a shell to protect the core on the surface of the core, and the quantum dot or quantum rod as the surface of the shell. A ligand component for dispersing in a solvent may be surrounded. For example, a quantum dot or quantum rod is a structure in which an energy bandgap of a component constituting a core is surrounded by an energy bandgap of a shell, and electrons and holes move toward the core, and electrons and holes move in the core. As recombination takes place, it can have a light-emitting type-core/shell structure that emits energy as light.

When the quantum dots or quantum rods form a type-I core/shell structure, the core is a portion where light emission occurs substantially, and the emission wavelength of the quantum dots or quantum rods is determined according to the size of the core. In order to receive the quantum confinement effect, the core must have a size smaller than the exciton Bohr radius according to each material and have an optical band gap at that size.

On the other hand, the shell constituting the quantum dot or quantum rod promotes the quantum confinement effect of the core and determines the stability of the quantum dot or quantum rod. Atoms exposed on the surface of a colloidal quantum dot or quantum rod of a single structure have an electron state (lone pair electron) that does not participate in chemical bonding unlike internal atoms. The energy levels of these surface atoms are positioned between the conduction band edge and the valence band edge of the quantum dot or quantum rod to trap charges, resulting in surface defects. The luminous efficiency of quantum dots or quantum rods may decrease due to the non-radiative recombination process of excitons caused by surface defects, and the trapped charges react with external oxygen and compounds to form quantum dots or quantum rods. It may cause a change in the chemical composition or permanently lose the electrical/optical properties of the quantum dots or quantum rods.

Thus, in one preferred embodiment, quantum dots or quantum rods may have a core/shell heterostructure. In order for the shell to be efficiently formed on the surface of the core, the lattice constant of the material constituting the shell should be similar to that of the material constituting the core. By enclosing the surface of the core with a shell, oxidation of the core is prevented to improve the chemical stability of quantum dots or quantum rods, to minimize the loss of excitons due to surface traps on the surface of the core, and to prevent energy loss due to molecular vibration Thus, the quantum efficiency can be improved.

Quantum dots or quantum rods may be semiconductor nanocrystals or metal oxide particles having a quantum confinement effect. For example, the quantum dot or quantum rod may include a nano-semiconductor compound of group II-VI, group I-III-VI, or group III-V. More specifically, the core and/or shell constituting the quantum dot or quantum rod may be a II-VI compound semiconductor nanocrystal such as CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgS, HgTe or a combination thereof; Group III-V compound semiconductor nanocrystals such as GaP, GaAs, GaSb, InP, InAs, InSb or combinations thereof; Group IV-VI compound semiconductor nanocrystals such as PbS, PbSe, PbTe or any combination thereof; Group I-III-VI compound semiconductor nanocrystals such as AgGaS ₂ , AgGaSe ₂ , AgGaTe ₂ , AgInS ₂ , CuInS ₂ , CuInSe ₂ , CuGaS ₂ , CuGaSe ₂ or combinations thereof; metal oxide nanoparticles such as ZnO, TiO ₂ or combinations thereof; core/shell structures such as CdSe/ZnSe, CdSe/ZnS, CdS/ZnSe, CdS/ZnS, ZnSe/ZnS, InP/ZnS ZnO/MgO, or any combination thereof. Semiconductor nanoparticles may be doped or undoped with rare earth elements such as Eu, Er, Tb, Tm, Dy or any combination thereof, or transition metal elements such as Mn, Cu, Ag, Al or any combination thereof. Can be doped with a combination of.

For example, the cores constituting the quantum dots or quantum rods are ZnSe, ZnTe, CdSe, CdTe, InP, ZnCdS, Cu _x In _1-x S, Cu _x In _1-x Se, Ag _x In _1-x S and these It may be selected from the group consisting of a combination of. In addition, the shells constituting the quantum dots or quantum rods are ZnS, GaP, CdS, ZnSe, CdS/ZnS, ZnSe/ZnS, ZnS/ZnSe/CdSe, GaP/ZnS, CdS/CdZnS/ZnS, ZnS/CdSZnS, Cd _X Zn It may be selected from the group consisting of _1-x S and combinations thereof.

On the other hand, the quantum dots are homogeneous alloy quantum dots or alloy quantum dots such as gradient alloy quantum dots (alloy QD; for example, CdS _x Se _1-x , CdSe _x Te _1-x , Zn _x Cd _1-x Se) may be

When the light emitting material layer 150 is made of inorganic light emitting particles such as quantum dots or quantum rods, the first charge transfer layer 140, for example, the hole transport layer ( 144), the light emitting material layer 150 is formed by volatilizing the solvent.

In one exemplary embodiment, the light-emitting material layer 150 may include quantum dots or quantum rods, which are nano-inorganic light-emitting particles having PL emission characteristics of 440 nm, 530 nm, and 620 nm, so that a white light-emitting diode can be manufactured. Optionally, the light-emitting material layer 150 includes quantum dots or quantum rods, which are light-emitting nanoparticles having one of red, green, and blue colors, and may be implemented to individually emit light of any one of them.

The band gap of the organic compounds represented by Chemical Formulas 1 to 3 is wider than, for example, the band gap of the core constituting the inorganic light emitting material. In an exemplary embodiment, organic compounds represented by Chemical Formulas 1 to 3 may be used as a host of the light emitting material layer (EML) 150, and the above-described inorganic light emitting material may be used as a dopant (or guest) of the light emitting material layer (EML). can be used as Accordingly, holes and electrons are transferred to the light emitting material layer 150, and energy for forming excitons can be efficiently transferred from the organic compound according to the present invention to the inorganic light emitting material. For example, in the light emitting material layer (EML, 150), the ratio of the organic compound represented by Chemical Formulas 1 to 3 and the inorganic light emitting material is approximately 1:5 to 5:1, preferably 1:3 to 3:1, more preferably Preferably, they may be used in combination at a weight ratio of 1:2 to 2:1, but the present invention is not limited thereto.

At this time, the organic compounds represented by Chemical Formulas 1 to 3 may be subjected to a solution process. Therefore, in one exemplary embodiment, the light emitting material layer 150 is coated with a dispersion containing an inorganic light emitting material such as light emitting nanoparticles, such as quantum dots or quantum rods, and organic compounds represented by Chemical Formulas 1 to 3 in a solvent. It may be formed by coating on the first charge transfer layer 140 through a solution process and volatilizing the solvent. As a method of forming the light emitting material layer 150, a solution process such as spin coating, drop coating, dip coating, spray coating, roll coating, and flow coating, as well as a casting process, screen printing, or inkjet printing, is used alone or in combination. can be layered.

Illustratively, the organic compounds represented by Chemical Formulas 1 to 3 may function as a matrix for dispersing the inorganic light emitting material. Therefore, as shown in FIG. 3, the light emitting material layer (EML, 150) has a smooth cross-sectional shape with respect to the adjacent charge transfer layer, for example, the hole transport layer (144, HTL) and the electron transport layer (164, ETL), and has an interface form Since the light emitting diode 100 including the light emitting layer 130 has excellent morphological characteristics, holes and electrons can be uniformly injected into the entire area of the light emitting diode 100, so that holes and electrons can pass through the light emitting material layer 150. Excitons can be formed efficiently.

In addition, organic compounds represented by Chemical Formulas 1 to 3 have higher HOMO energy levels than inorganic light emitting materials. Therefore, as shown in FIG. 4, the HOMO (or valence band) energy level of the light emitting material layer (EML) using the inorganic light emitting material in combination with the organic compound represented by Chemical Formulas 1 to 3 is the light emitting material using only the inorganic light emitting material. It is higher than the valence band energy level of the layer. Accordingly, the difference (ΔG' _H ) between the HOMO energy level of the hole transport layer (HTL) and the HOMO energy level of the light emitting material layer (EML) is greatly reduced, resulting in an energy barrier between the hole transport layer (HTL) and the light emitting material layer (EML). can be removed.

That is, by applying the organic compound represented by Chemical Formulas 1 to 3 to the light emitting material layer (EML), the difference between the HOMO energy level of the hole transport layer (HTL) and the HOMO energy level of the light emitting material layer (EML) (ΔG' _H ) Is equal to the difference (ΔG L ) between the lowest unoccupied molecular orbital (LUMO) energy level of the electron transport layer (ETL) and the LUMO energy level of the light emitting material layer ( _EML ) or does not have a large difference. .

As described above, by using the organic compounds represented by Chemical Formulas 1 to 3 in the light emitting material layer, holes and electrons are injected into the light emitting material layer (EML) in a balanced manner to form excitons, so electrons that disappear without forming excitons decreases or disappears In addition, light emission can be efficiently generated from the light emitting material injected into the light emitting material layer EML instead of the interface between the light emitting material layer EML and the adjacent charge transfer layers HTL and ETL. Accordingly, the light emitting efficiency of the light emitting diode 100 can be maximized, and power consumption can be reduced because it can be driven at a low voltage.

Meanwhile, the second charge transfer layer 160 is positioned between the light emitting material layer 150 and the second electrode 120 . In this embodiment, the second charge transfer layer 160 may be an electron transfer layer supplying electrons to the light emitting material layer 150 . In one exemplary embodiment, the second charge transfer layer 160 is an electron injection layer positioned adjacent to the second electrode 120 between the second electrode 120 and the light emitting material layer 150. ;

The electron injection layer 162 facilitates electron injection from the second electrode 120 into the light emitting material layer 150 . For example, the electron injection layer 162 is made of a material in which fluorine is doped or bonded to a metal such as Al, Cd, Cs, Cu, Ga, Ge, In, Li, Al, Mg, In, Li, Ga, Titanium dioxide (TiO ₂ ) doped or undoped with Cd, Cs, Cu, etc., zinc oxide (ZnO), zirconium oxide (ZrO), tin oxide (SnO ₂ ), tungsten oxide (WO ₃ ), tantalum oxide (Ta ₂ O ₃ ) may be made of a metal oxide such as.

The electron transport layer 164 transfers electrons to the light emitting material layer 150 . The electron transport layer 164 may be made of an inorganic material and/or an organic material. When the electron transport layer 764 is made of an inorganic material, the electron transport layer 164 is titanium dioxide (TiO ₂ ) doped or undoped with Al, Mg, In, Li, Ga, Cd, Cs, Cu, or the like, or zinc oxide (ZnO). ), zinc magnesium oxide (ZnMgO), zirconium oxide (ZrO), tin oxide (SnO ₂ ), tungsten oxide (WO ₃ ), tantalum oxide (Ta ₂ O ₃ ), hafnium oxide (HfO ₃ ), aluminum oxide (Al ₂ O ₃ ), zirconium silicon oxide (ZrSiO ₄ ), barium titanium oxide (BaTiO ₃ ), barium zirconium oxide (BaZrO ₃ ) and/or metal/non-metal oxides such as Al, Mg, In, Li, Ga, Cd, Cs, It may be made of an inorganic material selected from the group consisting of semiconductor particles such as CdS, ZnSe, and ZnS doped or not doped with Cu, nitrides such as Si ₃ N ₄ , and combinations thereof.

When the electron transport layer 164 is made of an organic material, the electron transport layer 164 includes an oxazole-based compound, an isoxazole-based compound, a triazole-based compound, an isothiazole-based compound, an oxadiazole-based compound, a thiadizaol-based compound, phenanthroline )-based compounds, perylene-based compounds, benzoxazole-based compounds, benzothiazole-based compounds, benzimidazole-based compounds, triazine-based compounds, or organic materials such as aluminum complexes may be used. Specifically, the organic material capable of constituting the electron transport layer 164 is 3-(biphenyl-4-yl)-5-(4-tetrabutylphenyl)-4-phenyl-4H-1,2,4-tria Sol (3-(biphenyl-4-yl)-5-(4-tertbutylphenyl)-4-phenyl-4H-1,2,4-triazole, TAZ), bathocuproine (2,9-dimethyl- 4,7-diphenyl-1,10-phenanthroline; BCP), 2,2',2"-(1,3,5-benzyntriyl)-tris(1-phenyl-1-H-benzimiazole) (2,2',2"-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole); TPBi), 2-[4-(9,10-di-2-naf Talenyl-2-anthracenyl)phenyl]-1-phenyl-1H-benzimidazole (2-[4-(9,10-Di-2-naphthalenyl-2-anthracenyl)phenyl]-1-phenyl-1H- benzimidazole), tris (8-hydroxyquinoline) aluminum (Tris (8-hydroxyquinoline) aluminum; Alq ₃ ), bis (2-methyl-8-quinolinato) -4-phenylphenolate aluminum (Ⅲ) (bis ( 2-methyl-8-quninolinato)-4-phenylphenolatealuminum (III); Balq), bis(2-methyl-quinolinato) (triphenylsiloxy), 8-hydroxy-quinolinato lithium (8-hydroxy- quinolinato lithium, Liq), aluminum (Ⅲ) (bis(2-methyl-quinolinato)(tripnehylsiloxy) aluminum (Ⅲ); Salq), 2-phenyl-9-(3-(2-(phenyl-1,10-phenan) 2-phenyl-9-(3-(2-phenyl-1,10-phenanthrolin-9-yl)phenyl)-1,10-phenanthroline ) and materials composed of combinations thereof, but the present invention is not limited thereto.

In another optional embodiment, the electron transport layer 164 may be formed of organic compounds represented by Chemical Formulas 1 to 3.

Similar to the first charge transfer layer 140, although the second charge transfer layer 160 is shown as two layers of an electron injection layer 162 and an electron transport layer 164 in FIG. 3, the second charge transfer layer 160 ) may be formed of only one layer of the electron transport layer 164. In addition, the second charge transfer layer 160 may be formed with one layer of the electron transport layer 164 obtained by blending cesium carbonate with the aforementioned inorganic electron transport material.

The second charge transfer layer 160 including the electron injection layer 162 and/or the electron transport layer 164 can be applied by spin coating, drop coating, dip coating, spray coating, roll coating, flow coating, casting process, Solution processes such as screen printing or inkjet printing may be used alone or in combination. For example, the electron injection layer 162 and the electron transport layer 164 may be stacked to a thickness of 10 to 200 nm, preferably 10 to 100 nm.

For example, a mixed charge transport layer (CTL) in which the hole transport layer 144 constituting the first charge transfer layer 140 is made of an organic material and the second charge transfer layer 160 is made of an inorganic material is formed. When introduced, light emitting characteristics of the light emitting diode 100 may be improved.

On the other hand, when holes pass through the light emitting material layer 150 and move to the second electrode 120 or electrons pass through the light emitting material layer 150 and go to the first electrode 110, the lifespan and efficiency of the device are reduced. can bring To prevent this, in the light emitting diode 100 according to the first exemplary embodiment of the present invention, at least one exciton blocking layer may be positioned adjacent to the light emitting material layer 150 .

For example, the light emitting diode 100 according to the first embodiment of the present invention has an electron blocking layer capable of controlling or preventing the movement of electrons between the hole transport layer 144 and the light emitting material layer 150. , EBL) may be located. For example, the electron blocking layer is TCTA, tris [4- (diethylamino) phenyl] amine (tris [4- (diethylamino) phenyl] amine), N- (biphenyl-4-yl) -9,9-dimethyl -N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine, tri-p-tolylamine, 1,1- Bis(4-(N,N-di(p-tolyl)amino)phenyl)cyclohexane(1,1-bis(4-(N,N'-di(ptolyl)amino)phenyl)cyclohexane; TAPC),m -MTDATA, 1,3-bis (N-carbazolyl) benzene (1,3-bis (N-carbazolyl) benzene; mCP), 3,3'-bis (N-carbazolyl) -1,1'-bi Phenyl (3,3'-bis (N-carbazolyl) -1,1'-biphenyl; mCBP), Poly-TPD, copper phthalocyanine (CuPc), DNTPD and / or 1,3,5-tris [4 -(diphenylamino)phenyl]benzene (1,3,5-tris[4-(diphenylamino)phenyl]benzene; TDAPB).

In addition, a hole blocking layer (HBL) is positioned as a second exciton blocking layer between the light emitting material layer 150 and the electron transport layer 164, so that holes are formed between the light emitting material layer 150 and the electron transport layer 164. movement can be prevented. In one exemplary embodiment, oxadiazole-based, triazole-based, phenanthroline-based, benzoxazole-based, benzothiazole-based, benzimidazole-based, triazine-based, etc. that can be used for the electron transport layer 164 as a material for the hole blocking layer. Organic derivatives of can be used.

For example, the hole blocking layer is 2,9-dimethyl-4,7-diphenyl-1 having a lower HOMO (highest occupied molecular orbital) energy level compared to the material used in the light emitting material layer 150. ,10-phenanthroline (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline; BCP), BAlq, Alq3, PBD, spiro-PBD, and/or Liq.

In one optional embodiment, the exciton blocking layer may be formed of organic compounds represented by Chemical Formulas 1 to 3.

As described above, according to the first embodiment of the present invention, the light emitting layer 130, for example, the light emitting material layer 150 (EML) may be formed of organic compounds represented by Chemical Formulas 1 to 3. The organic compounds represented by Chemical Formulas 1 to 3 may function as a matrix for dispersing the inorganic light emitting material. As the interface between the light emitting material layer 150 and the adjacent charge transfer layer is formed smoothly, the morphology characteristics of the light emitting diode 100 are improved. In addition, the HOMO energy barrier between the light emitting material layer 150 and the hole transport layer 144 is reduced. As holes and electrons are injected into the entire area of the light emitting material layer 150 in a balanced manner, the light emitting efficiency of the light emitting diode 100 is improved, and power consumption can be reduced because it can be driven at a low voltage.

Meanwhile, in FIGS. 3 and 4, the hole transfer layer is positioned between the light emitting material layer and the first electrode having a relatively low work function value, and the electron transfer layer is positioned between the light emitting material layer and the second electrode having a relatively high work function value. A light emitting diode having a normal structure having a normal structure has been described. A light emitting diode may have an inverted structure rather than a normal structure, which will be described. 5 is a cross-sectional view schematically showing a light emitting diode having an inverted structure according to the second exemplary embodiment of the present invention, and FIG. 6 is a light emitting diode according to the second exemplary embodiment of the present invention. It is a diagram schematically showing the bandgap energy of materials constituting the constituting electrode and the light emitting layer.

As shown in FIG. 5, the light emitting diode 200 according to the second exemplary embodiment of the present invention includes a first electrode 210, a second electrode 220 facing the first electrode 210, a first The light emitting layer 230 including the light emitting material layer 250 positioned between the electrode 210 and the second electrode 220 is included. The light emitting layer 230 includes a first charge transfer layer 240 positioned between the first electrode 210 and the light emitting material layer 250, and positioned between the second electrode 220 and the light emitting material layer 250. A second charge transfer layer 260 may be further included.

In the second embodiment of the present invention, the first electrode 210 may be a cathode such as an electron injection electrode. For example, the first electrode 810 is doped with ITO, IZO, ITZO, ICO, SnO ₂ , In ₂ O ₃ , Cd:ZnO, F:SnO ₂ , In:SnO ₂ , Ga:SnO ₂ and AZO. It may be an undoped metal oxide or a material including nickel (Ni), platinum (Pt), gold (Au), silver (Ag), iridium (Ir), or carbon nanotubes in addition to the above-mentioned metal oxide.

In the second embodiment of the present invention, the second electrode 220 may be an anode such as a hole injection electrode. For example, the second electrode 220 may be Ca, Ba, Ca/Al, LiF/Ca, LiF/Al, BaF ₂ /Al, CsF/Al, CaCO ₃ /Al, BaF ₂ /Ca/Al, Al, Mg, It may be Au:Mg or Ag:Mg. For example, the first electrode 810 and the second electrode 220 may be stacked to a thickness of 30 to 300 nm.

In the second embodiment of the present invention, the first charge transfer layer 240 may be an electron transfer layer supplying electrons to the light emitting material layer 250 . In one exemplary embodiment, the first charge transfer layer 240 includes an electron injection layer 242 positioned adjacent to the first electrode 210 between the first electrode 210 and the light emitting material layer 250 and , An electron transport layer 244 positioned adjacent to the light emitting material layer 250 between the first electrode 210 and the light emitting material layer 250 .

The electron injection layer 242 is made of a material in which fluorine is doped or bonded to a metal such as Al, Cd, Cs, Cu, Ga, Ge, In, or Li, or Al, Mg, In, Li, Ga, Cd, or Cs. , TiO ₂ , ZnO, ZrO, SnO ₂ , WO ₃ , Ta ₂ O ₃ doped or not doped with Cu or the like.

The electron transport layer 244 may be made of an inorganic material and/or an organic material. When the electron transport layer 244 is made of an inorganic material, the electron transport layer 244 is TiO ₂ , ZnO, ZnMgO, ZrO, SnO ₂ doped or undoped with Al, Mg, In, Li, Ga, Cd, Cs, or Cu. , WO ₃ , Ta ₂ O ₃ , HfO ₃ , Al ₂ O ₃ , ZrSiO ₄ , BaTiO ₃ , metal/non-metal oxides such as BaZrO ₃ and/or Al, Mg, In, Li, Ga, Cd, Cs, Cu, etc. It may be made of an inorganic material selected from the group consisting of semiconductor particles such as doped or undoped CdS, ZnSe, and ZnS, nitrides such as Si ₃ N ₄ , and combinations thereof.

When the electron transport layer 244 is made of an organic material, the electron transport layer 244 may include an oxazole-based compound, an isoxazole-based compound, a triazole-based compound, an isothiazole-based compound, an oxidiazole-based compound, a thiadizaol-based compound, and perylene. A base compound or an aluminum complex can be used. Specifically, organic materials capable of constituting the electron transport layer 244 include TAZ, BCP, TPBi, 2-[4-(9,10-di-2-naphthalenyl-2-anthracenyl)phenyl]-1- Phenyl-1H-benzimidazole, Alq ₃ , Balq, LIQ, Salq, 2-phenyl-9-(3-(2-(phenyl-1,10-phenanthrolin-9-yl)phenyl)-1,10 - It may be made of an organic material selected from the group consisting of phenanthroline and combinations thereof, but the present invention is not limited thereto. It may also consist of a compound.

Meanwhile, the first charge transfer layer 240 may be formed of only one layer of the electron transport layer 244 . In addition, the first charge transfer layer 240 may be formed with one layer of the electron transport layer 244 obtained by blending cesium carbonate with the above-described electron transport material composed of inorganic particles. For example, the electron injection layer 242 and the electron transport layer 244 may be stacked to a thickness of 10 to 200 nm, preferably 10 to 100 nm.

The light emitting material layer 250 may include inorganic light emitting particles and organic compounds represented by Chemical Formulas 1 to 3. The inorganic light-emitting particles may be nano-inorganic light-emitting particles such as quantum dots or quantum rods. Quantum dots or quantum rods may have a single structure or a heterogeneous core/shell structure.

Quantum dots or quantum rods may be semiconductor nanocrystals or metal oxide particles having a quantum confinement effect. For example, the quantum dot or quantum rod may include a nano-semiconductor compound of group II-VI, group I-III-VI, or group III-V. More specifically, the core and / or shell constituting the quantum dot or quantum rod may be a group II to VI compound semiconductor nanocrystal such as CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgS, HgTe or a combination thereof; Group III to V or IV to VI compound semiconductor nanocrystals such as GaP, GaAs, GaSb, InP, InAs and InSb; PbS, PbSe, PbTe or any combination thereof; AgGaS ₂ , AgGaSe ₂ , AgGaTe ₂ , CuInS ₂ , CuInSe ₂ , CuGaS ₂ , CuGaSe ₂ nanocrystals; metal oxide nanoparticles such as ZnO, TiO ₂ or combinations thereof; CdSe/ZnSe, CdSe/ZnS, CdS/ZnSe, CdS/ZnS, ZnSe/ZnS, InP/ZnS ZnO/MgO, or any combination thereof. Semiconductor nanoparticles may be doped or undoped with rare earth elements such as Eu, Er, Tb, Tm, Dy or any combination thereof, or transition metal elements such as Mn, Cu, Ag, Al or any combination thereof. Can be doped with a combination of.

When the light emitting material layer 250 is made of inorganic light emitting particles such as quantum dots or quantum rods, a dispersion solution containing inorganic light emitting materials such as quantum dots or quantum rods and organic compounds represented by Chemical Formulas 1 to 3 is used in a solvent. After being coated on the first charge transfer layer 240, for example, the electron transport layer 244 through the process, the light emitting material layer 250 is formed by volatilizing the solvent.

Meanwhile, in the second embodiment of the present invention, the second charge transfer layer 260 may be a hole transfer layer supplying holes to the light emitting material layer 250 . In one exemplary embodiment, the second charge transfer layer 260 includes a hole injection layer 262 positioned adjacent to the second electrode 220 between the second electrode 220 and the light emitting material layer 250 and , a hole transport layer 264 positioned adjacent to the light emitting material layer 250 between the second electrode 220 and the light emitting material layer 250 .

The hole injection layer 262 is PEDOT:PSS, TDATA doped with F4-TCNQ, for example, p-doped phthalocyanine such as ZnPc doped with F4-TCNQ, α-NPD doped with F4-TCNQ, and HAT-CN. And it may be made of a material selected from the group consisting of combinations thereof, but the present invention is not limited thereto. For example, a dopant such as F4-TCNQ may be doped in an amount of 1 to 30% by weight with respect to the host. The hole injection layer 262 may be omitted depending on the structure and shape of the light emitting diode 200 . In an optional embodiment, the hole injection layer 262 may be formed of organic compounds represented by Chemical Formulas 1 to 3.

The hole transport layer 264 may be made of an inorganic or organic material. For example, when the hole transport layer 264 is made of an organic material, the hole transport layer 264 may include arylamines such as CBP, α-NPD, TPD, spiro-TPD, DNTPD, and TCTA, polyaniline, polypyrrole, Poly(phenylenevinylene), copper phthalocyanine, aromatic tertiary amine or polynuclear aromatic tertiary amine, 4,4'-bis(p-carbazolyl)-1,1'- Biphenyl compounds, N,N,N',N'-tetraarylbenzidine, PEDOT:PSS and its derivatives, poly-N-vinylcarbazole and its derivatives, poly(para)phenyls such as MEH-PPV and MOMO-PPV Lenvinylene and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, poly(spiro-fluorene) and its derivatives, NPB, m-MTDATA, TFB, poly - It may be made of an organic material selected from the group consisting of TPD, piro-NPB, and combinations thereof. For example, the hole transport layer 264 may be formed of an organic material having a triphenyl amine moiety represented by Chemical Formulas 4 to 6. In another optional embodiment, the hole transport layer 264 may be formed of organic compounds represented by Chemical Formulas 1 to 3.

When the hole transport layer 264 is made of an inorganic material, the hole transport layer 264 is a metal oxide such as NiO, MoO ₃ , Cr ₂ O ₃ , Bi ₂ O ₃ or p-type ZnO, copper thiocyanate (CuSCN), Mo ₂ It may be made of an inorganic material selected from the group consisting of S, non-oxidizing equivalents such as p-type GaN, or combinations thereof.

The second charge transfer layer 260 may be formed of a single layer. For example, the hole injection layer 262 may be omitted and the second charge transfer layer 260 may include only the hole transport layer 264 . The hole injection layer 262 and the hole transport layer 264 may have a thickness of 10 nm to 200 nm, preferably 10 nm to 100 nm, but the present invention is not limited thereto.

Similar to the first embodiment, in the light emitting diode 200 according to the second exemplary embodiment of the present invention, at least one exciton blocking layer may be positioned adjacent to the light emitting material layer 250 . For example, the light emitting diode 200 is positioned between the light emitting material layer 250 and the hole transport layer 264 to control and prevent the movement of electrons, and/or the electron blocking layer and/or the electron transport layer 244 and the light emitting material. A hole blocking layer positioned between the layers 250 to control or prevent the movement of holes may be further included. The exciton blocking layer may be formed of organic compounds represented by Chemical Formulas 1 to 3.

In the light emitting diode 200 according to the second embodiment of the present invention, the light emitting layer 230, for example, the light emitting material layer 250 (EML) includes organic compounds represented by Chemical Formulas 1 to 3. The organic compounds represented by Chemical Formulas 1 to 3 may function as a matrix for dispersing the inorganic light emitting material. The interface between the light emitting material layer 250 and the charge transfer layer adjacent to the light emitting material layer 250, for example, the electron transport layer 244 and the hole transport layer 264, is formed smoothly, resulting in morphological characteristics of the light emitting diode 100. As this is improved, holes and electrons can be uniformly injected into the light emitting material layer EML over the entire area of the light emitting diode 100 .

In addition, the HOMO energy levels of organic compounds represented by Chemical Formulas 1 to 3 are higher than those of inorganic light emitting materials. Therefore, as schematically shown in FIG. 6, when compared to the HOMO energy level of the light emitting material layer (EML) composed of only the inorganic light emitting material, the light emitting material layer (EML) using the organic compounds of Formulas 1 to 3 and the inorganic light emitting material in combination ), the HOMO energy level increases. The difference (ΔG' _H ) between the HOMO energy level of the hole transport layer (HTL) and the HOMO energy level of the light emitting material layer (EML) is greatly reduced to remove the energy barrier between the hole transport layer (HTL) and the light emitting material layer (EML). can

That is, by applying the organic compound represented by Chemical Formulas 1 to 3 to the light emitting material layer (EML), the difference between the HOMO energy level of the hole transport layer (HTL) and the HOMO energy level of the light emitting material layer (EML) (ΔG' _H ) is equal to or does not have a large difference (ΔG _L ) between the LUMO energy level of the electron transport layer (ETL) and the LUMO energy level of the light emitting material layer (EML). Since holes and electrons are injected into the light emitting material layer (EML) in a balanced manner to form excitons, electrons that are extinguished without forming excitons are reduced or eliminated. In addition, the light emitting material injected into the light emitting material layer EML efficiently emits light, not the interface between the light emitting material layer EML and the adjacent charge transfer layers HTL and ETL. Accordingly, the light emitting efficiency of the light emitting diode 200 can be maximized, and power consumption can be reduced because it can be driven at a low voltage.

Accordingly, a light emitting diode in which organic compounds represented by Chemical Formulas 1 to 3 are applied to the light emitting layer may be applied to a light emitting device such as a lighting device or a display device. As an example, a light emitting device having a light emitting diode in which an organic compound according to the present invention is applied to a hole transfer layer will be described. 7 is a schematic cross-sectional view of a light emitting display device according to an exemplary embodiment of the present invention.

As shown in FIG. 7 , the light emitting display device 300 is connected to a substrate 310, a driving element Tr positioned on the substrate 310, and the driving thin film transistor Tr. A light emitting diode 400 is included.

A semiconductor layer 322 made of an oxide semiconductor material or polycrystalline silicon is formed on the substrate 310 . When the semiconductor layer 322 is made of an oxide semiconductor material, a light-shielding pattern (not shown) may be formed under the semiconductor layer 322, and the light-shielding pattern prevents light from entering the semiconductor layer 322 to prevent light from entering the semiconductor layer 322. Layer 322 is prevented from being degraded by light. Alternatively, the semiconductor layer 322 may be made of polycrystalline silicon, and in this case, both edges of the semiconductor layer 322 may be doped with impurities.

A gate insulating layer 324 made of an insulating material is formed on the semiconductor layer 322 . The gate insulating layer 324 may be formed of an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx). A gate electrode 330 made of a conductive material such as metal is formed on the gate insulating layer 324 corresponding to the center of the semiconductor layer 322 .

An interlayer insulating layer 332 made of an insulating material is formed on the gate electrode 330 . The interlayer insulating film 332 may be formed of an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx), or an organic insulating material such as benzocyclobutene or photo-acryl. there is.

The interlayer insulating layer 332 has first and second semiconductor layer contact holes 334 and 336 exposing both sides of the semiconductor layer 322 . The first and second semiconductor layer contact holes 334 and 336 are spaced apart from the gate electrode 330 on both sides of the gate electrode 330 . A source electrode 340 and a drain electrode 342 made of a conductive material such as metal are formed on the interlayer insulating film 332 .

The source electrode 340 and the drain electrode 342 are spaced apart from each other about the gate electrode 330, and the semiconductor layer 322 passes through the first and second semiconductor layer contact holes 334 and 336, respectively. contact both sides The semiconductor layer 322, the gate electrode 330, the source electrode 340, and the drain electrode 342 form a driving thin film transistor Tr as a driving element.

In FIG. 7 , the driving thin film transistor Tr has a coplanar structure in which a gate electrode 330 , a source electrode 340 , and a drain electrode 342 are positioned on top of a semiconductor layer 322 . Alternatively, the driving thin film transistor Tr may have an inverted staggered structure in which a gate electrode is positioned under the semiconductor layer and a source electrode and a drain electrode are positioned above the semiconductor layer. In this case, the semiconductor layer may be made of amorphous silicon.

Although not shown, a gate line and a data line cross each other to define a pixel area, and a switching element connected to the gate line and the data line is further formed. The switching element is connected to the driving thin film transistor Tr, which is a driving element. In addition, the power wiring is formed to be spaced apart in parallel with the gate wiring or the data wiring, and a storage capacitor is further configured to maintain the voltage of the gate electrode of the driving thin film transistor (Tr), which is a driving element, constant during one frame. It can be.

Meanwhile, a protective layer 350 having a drain contact hole 352 exposing the drain electrode 342 of the driving thin film transistor Tr is formed to cover the driving thin film transistor Tr. For example, the protective layer 350 is formed of an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx), or an organic insulating material such as benzocyclobutene or photo-acryl. can be formed as

On the protective layer 350, a first electrode 410 connected to the drain electrode 342 of the driving thin film transistor Tr through the drain contact hole 352 is formed separately for each pixel area. The first electrode 410 may be an anode or a cathode, and may be made of a conductive material having a relatively high work function value. For example, the first electrode 410 is doped with ITO, IZO, ITZO, ICO, SnO ₂ , In ₂ O ₃ , Cd:ZnO, F:SnO ₂ , In:SnO ₂ , Ga:SnO ₂ and AZO. It may be an undoped or undoped metal oxide, or may be made of a metal material including nickel (Ni), platinum (Pt), gold (Au), silver (Ag), iridium (Ir), or carbon nanotubes in addition to the above-mentioned metal oxides. .

Meanwhile, when the light emitting display device 300 of the present invention is a top-emission type, a reflective electrode or a reflective layer may be further formed below the first electrode 410 . For example, the reflective electrode or the reflective layer may be made of an aluminum-palladium-copper (APC) alloy.

In addition, a bank layer 368 covering an edge of the first electrode 410 is formed on the passivation layer 350 . The bank layer 368 exposes the center of the first electrode 410 corresponding to the pixel area.

A light emitting layer 430 is formed on the first electrode 410 . The light emitting layer 430 may be formed of only light emitting material layers, but may include a plurality of charge transfer layers to increase light emitting efficiency. For example, in FIG. 7 , the light emitting layer 430 includes a first charge transfer layer 440, a light emitting material layer 450, and a second charge transfer layer sequentially stacked between the first electrode 410 and the second electrode 420. It is exemplified by the layer 460 . For example, the first charge transfer layer 440 may be a hole transfer layer, and may include a hole injection layer 142 (see FIG. 2) made of an organic material and a hole transport layer 144 (see FIG. 2).

The light emitting material layer 440 may include an inorganic light emitting material and organic compounds represented by Chemical Formulas 1 to 3. Meanwhile, the second charge transfer layer 450 may be an electron transfer layer, and may include an electron injection layer 162 (see FIG. 2) and an electron transport layer 164 (see FIG. 2). For example, the second charge transfer layer 450 may be formed of an inorganic or organic material.

A second electrode 420 is formed on the substrate 310 on which the light emitting layer 430 is formed. The second electrode 420 is positioned on the front surface of the display area and may be made of a conductive material having a relatively low work function value, and may be a cathode or an anode. For example, the second electrode 420 may be Ca, Ba, Ca/Al, LiF/Ca, LiF/Al, BaF ₂ /Al, CsF/Al, CaCO ₃ /Al, BaF ₂ /Ca/Al, Al, Mg, Au:Mg or Ag:Mg.

7 exemplarily, the first charge transfer layer 440 as a hole transfer layer is positioned between the first electrode 410 and the light emitting material layer 450, and the second electrode 420 and the light emitting material layer 450 It shows the light emitting diode 400 of normal structure in which the second charge transfer layer 460 as an electron transfer layer is located therebetween.

In another embodiment, a first charge transfer layer as an electron transfer layer is located between the first electrode 410 and the light emitting material layer 450, and a hole transfer layer is between the second electrode 420 and the light emitting material layer 450. A light emitting diode having an inverted structure in which the second charge transfer layer is located may be manufactured.

An organic compound represented by Chemical Formulas 1 to 3 is applied to the light emitting material layer 450 in combination with an inorganic light emitting material to have a smooth cross-sectional shape between the light emitting material layer 450 and the adjacent charge transfer layers 440 and 460. interfaces can be formed. Morphological characteristics of the light emitting diode 400 are improved, and charges are uniformly injected into the entire area of the light emitting diode 400 . In addition, the difference in HOMO energy level between the light emitting material layer 450 and the first charge transfer layer 440 or the second charge transfer layer 460, which may be a hole transfer layer, is reduced, so that the hole transfer layer and the light emitting material layer ( 450) can remove the HOMO energy barrier between them. The organic compounds represented by Chemical Formulas 1 to 3 may be applied to the light emitting material layer 450 to improve charge transfer characteristics and induce injection of holes and electrons into the light emitting material layer 450 in a balanced manner. As holes and electrons are injected into the light emitting material layer 450 in a balanced manner, the light emitting efficiency of the light emitting diode 400 and the light emitting display device 300 is improved, and power consumption can be reduced by driving at a low voltage.

Hereinafter, the present invention will be described through exemplary embodiments, but the present invention is not limited to the technical idea described in the following examples.

Synthesis Example 1: Synthesis of Compound H1

(1) Synthesis of 3-bromo-N-phenylpyridin-2-amine

4-amino-2-bromopyridine (10 g, 57.8 mmol), iodobenzene (12.38 g, 60.68 mmol), 4,5-Bis(diphenyl phosphino)-9,9-dimerhylxanthene (0.334 g, 0.58 mmol) in a round bottom flask , palladium(II)acetate (0.13 g, 0.58 mmol), and sodium-tert-butoxide (8.39 g, 87.27 mmol) were added and dissolved in 75 mL of toluene, followed by refluxing and stirring for 24 hours. After HPLC confirmation, column (MC: Hex = 1: 2) was performed to obtain 8.0 g of solid 3-bromo-N-phenylapyridine-2-amine (yield: 55.6%).

(2) Synthesis of 9H-pyrido[2,3-b]indole

3-bromo-N-phenylpyridin-2-amine (7.5 g, 30 mmol), (2-biphenyl)dicyclohexylphosphine (0.633 g, 1.81 mmol), palladium(II)acetate (0.13 g, 0.58 mmol), After adding 1,8-diazabicyclo[5.4.0]undec-7-ene (9.2 mL, 60 mmol) and dissolving in 150 mL of dimethylacetamide, the mixture was refluxed and stirred for 24 hours. After confirming by HPLC, the reaction was terminated, the solvent was evaporated, and column (EA: HEX = 6: 1) was performed to obtain 3.5 g of 9H-pyrido[2,3-b]indole (yield: 70%).

(3) Synthesis of 9-(4-bromophenyl)-9H-pyrido[2,3-b]indole

9H-pyrido[2,3-b]indole (3.5 g, 21 mmol), 1-bromo-4-iodobenzene (8.83 g, 31 mmol), copper(Ⅰ)iodide (0.8 g, 4.2 mmol) in a round bottom flask , (±)-trans-1,2-diaminocylohexane (0.48 g, 4.2 mmol), potassium phosphate tribasic (8.9 g, 42 mmol) were added and dissolved in 160 mL of toluene, followed by refluxing and stirring for 24 hours. After confirmation by TLC and HPLC, the reaction was terminated, and 5.19 g of 9-(4-bromophenyl)-9H-pyrido[2,3-b]indole was obtained by filtering and column (MC: HEX = 1:4) (yield: 75%).

(4) Synthesis of bis(4-propylphenyl)amine

In a round bottom flask, 4-propylbenzenamine (2.24 g, 11.25 mmol), 1-bromo-4-propylbenzene (1.01 g, 7.5 mmol), sodium tert-butoxide (1.075 g, 11.25 mmol), Tris(dibenzylideneacetone)dipalladium (0) (0.14 g, 0.15 mmol) was dissolved in 50 mL of toluene, then tri-tert-butylphosphine (0.03 g, 0.15 mmol) was added and stirred under reflux for 24 hours. After confirming by HPLC and LC-MASS, the reaction was terminated, and the solvent was removed and then extracted with MC/H2O. Column (EA: HEX = 1:4), re-precipitation in MC/hexane, and vacuum drying to obtain 1.70 g of bis(4-propylphenylamine) (yield: 89%).

(5) H1 synthesis

In a round bottom flask, bis(4-propylphenyl)amine (0.9 g, 3.55 mmol), 9-(4-bromophenyl)-9H-pyrido[2,3-b]indole (1.25 g, 3.9 mmol), sodium tert-butoxide (0.48 g, 4.97 mmol) and Tris(dibenzylideneacetone)dipalladium(0) (0.065 g, 0.071 mmol) were dissolved in 50 mL of toluene, then tri-tert-butylphosphine (0.03 g, 0.14 mmol) was added and stirred under reflux for 24 hours. . After confirming by HPLC and LC-MASS, the reaction was terminated, and after solvent removal, extraction was performed with MC/H2O. Column (EA: HEX = 1:4), reprecipitation in MC / hexane, vacuum drying and sublimation purification to obtain 1.25 g of compound H1 (yield: 71%).

Synthesis Example 2: Synthesis of Compound H2

(1) Synthesis of bis(4-butylphenyl)amine

In a round bottom flask, 4-butylbenzenamine (2.40 g, 11.25 mmol), 1-bromo-4-butylbenzene (1.12 g, 7.5 mmol), sodium tert-butoxide (1.075 g, 11.25 mmol), Tris(dibenzylideneacetone)dipalladium(0) (0.14 g, 0.15 mmol) was dissolved in 50 mL of toluene, then tri-tert-butylphosphine (0.03 g, 0.15 mmol) was added and stirred under reflux for 24 hours. After confirming by HPLC and LC-MASS, the reaction was terminated, and after removing the solvent, extraction was performed with MC / H2O. Column (EA: HEX = 1:4), reprecipitation in MC / hexane, and vacuum drying to obtain 1.85 g of bis(4-butylphenyl)amine (yield: 88%).

(2) H2 synthesis

In a round bottom flask, bis(4-butylphenyl)amine (1 g, 3.55 mmol), 9-(4-bromophenyl)-9H-pyrido[2,3-b]indole (1.25 g, 3.9 mmol), sodium tert-butoxide (0.48 g, 4.97 mmol) and Tris(dibenzylideneacetone)dipalladium(0)(0.065 g, 0.071 mmol) were dissolved in 50 mL of toluene, then tri-tert-butylphosphine (0.03 g, 0.14 mmol) was added and stirred under reflux for 24 hours. . After confirming by HPLC and LC-MASS, the reaction was terminated, and after solvent removal, extraction was performed with MC/H2O. Column (EA: HEX = 1:4), reprecipitation in MC/hexane, vacuum drying, and sublimation purification to obtain 1.45 g of H2 (yield: 78%).

Synthesis Example 3: Synthesis of Compound H3

(1) Synthesis of bis(4-pentylphenyl)amine

In a round bottom flask, 4-pentylbenzenamine (2.56 g, 11.25 mmol), 1-bromo-4-pentylbenzene (1.22 g, 7.5 mmol), sodium tert-butoxide (1.075 g, 11.25 mmol), Tris (dibenzylideneacetone) dipalladium (0) (0.14 g, 0.15 mmol) was dissolved in 50 mL of toluene, then tri-tert-butylphosphine (0.03 g, 0.15 mmol) was added and stirred under reflux for 24 hours. After confirming by HPLC and LC-MASS, the reaction was terminated, and after solvent removal, extraction was performed with MC/H2O. Column (EA: HEX = 1:4), reprecipitation in MC/hexane, and vacuum drying to obtain 1.75 g of bis(4-pentylphenyl)amine (yield: 75%).

(2) H3 synthesis

In a round bottom flask, bis(4-pentylphenyl)amine (1.1 g, 3.55 mmol), 9-(4-bromophenyl)-9H-pyrido[2,3-b]indole (1.25 g, 3.9 mmol), sodium tert-butoxide (0.48 g, 4.97 mmol) and Tris(dibenzylideneacetone)dipalladium(0)(0.065 g, 0.071 mmol) were dissolved in 50 mL of toluene, then tri-tert-butylphosphine (0.03 g, 0.14 mmol) was added and stirred under reflux for 24 hours. . After confirming by HPLC and LC-MASS, the reaction was terminated, and after solvent removal, extraction was performed with MC/H2O. Column (EA: HEX = 1:4), re-precipitation in MC/hexane, vacuum drying and sublimation purification to obtain 1.5 g of H3 (yield: 76%).

Synthesis Example 4: Synthesis of Compound H4

(1) Synthesis of bis(4-hexylphenyl)amine

In a round bottom flask, 4-hexylbenzenamine (2.7 g, 11.25 mmol), 1-bromo-4-hexylbenzene (1.33 g, 7.5 mmol), sodium tert-butoxide (1.075 g, 11.25 mmol), Tris (dibenzylideneacetone) dipalladium (0) (0.14 g, 0.15 mmol) was dissolved in 50 mL of toluene, then tri-tert-butylphosphine (0.03 g, 0.15 mmol) was added and stirred under reflux for 24 hours. After confirming by HPLC and LC-MASS, the reaction was terminated, and after solvent removal, extraction was performed with MC/H2O. Column (EA: HEX = 1:4), re-precipitation in MC/hexane, and vacuum drying to obtain 1.85 g of bis(4-hexylphenyl)amine (yield: 73%).

(2) H4 synthesis

In a round bottom flask, bis(4-hexylphenyl)amine (1.2 g, 3.55 mmol), 9-(4-bromophenyl)-9H-pyrido[2,3-b]indole (1.25 g, 3.9 mmol), sodium tert-butoxide (0.48 g, 4.97 mmol) and Tris(dibenzylideneacetone)dipalladium(0)(0.065 g, 0.071 mmol) were dissolved in 50 mL of toluene, then tri-tert-butylphosphine (0.03 g, 0.14 mmol) was added and stirred under reflux for 24 hours. . After confirming by HPLC and LC-MASS, the reaction was terminated, and after solvent removal, extraction was performed with MC/H2O. Column (EA: HEX = 1:4), reprecipitation in MC/hexane, vacuum drying and sublimation purification to obtain 1.55 g of H4 (yield: 75%).

Synthesis Example 5: Synthesis of Compound H5

(1) Synthesis of 4-(2-ethylhexyl)benzenamine

3-(chloromethyl)heptane (1 g, 6.7 mmol), 4-aminophenylboronic acid (1.1 g, 8.07 mmol), Palladium(II) acetate (0.083 g, 0.36 mmol), DavePhos (2-Dicyclohexylphosphino-2 Dissolve '-(N,N-dimethylamino)biphenyl, 0.22g, 0.55 mmol) and tripotassium phosphate (3.49 g, 16.46 mmol) in 60 mL of 1,4-dioxane, and stir under reflux for 4 hours. After confirming by HPLC and LC-MASS, the reaction was terminated, and after solvent removal, extraction was performed with MC/H2O. Column (MC: HEX = 1:6) and precipitated with methylene chloride/petroleum ether to obtain 1.22 g of 4-(2-ethylhexyl)benzenamine (yield: 88.6%).

(2) Synthesis of 1-bromo-4-(2-ethylhexyl)benzene

In a round bottom flask, 3-(chloromethyl)heptane (1 g, 6.7 mmol), 4-bromophenylboronic acid (1.62 g, 8.07 mmol), Palladium(II)acetate (0.083 g, 0.36 mmol), DavePhos (0.22g, 0.55 mmol) ), tripotassium phosphate (3.49 g, 16.46 mmol) was dissolved in 60 mL of 1,4-dioxane and stirred under reflux for 4 hours. After confirming by HPLC and LC-MASS, the reaction was terminated, and after solvent removal, extraction was performed with MC/H2O. column (MC: HEX = 1:6) and precipitated with methylene chloride/petroleum ether to obtain 1.4 g of 1-bromo-4-(2-ethylhexyl)benzene (yield: 77.6%).

(3) Synthesis of bis(4-(2-ethylhexyl)phenyl)amine

In a round bottom flask, 1-bromo-4-(2-ethylhexyl)benzene(1.0 g, 3.75 mmol), 4-(2-ethylhexyl)benzenamine(1.15 g, 5.6 mmol), sodium tert-butoxide(0.54 g, 5.6 mmol) ), Tris(dibenzylideneacetone)dipalladium(0)(0.14 g, 0.15 mmol) was dissolved in 50 mL of toluene, tri-tert-butylphosphine (0.03 g, 0.15 mmol) was added, and the mixture was refluxed and stirred for 24 hours. After confirming by HPLC and LC-MASS, the reaction was terminated, and after solvent removal, extraction was performed with MC/H2O. Column (EA: HEX = 1:4), re-precipitation in MC/hexane, and vacuum drying to obtain 1.2 g of bis(4-(2-ethylhexyl)phenyl)amine (yield: 81%).

(4) H5 synthesis

In a round bottom flask, bis(4-(2-ethylhexyl)phenyl)amine (1.2 g, 3.55 mmol), 9-(4-bromophenyl)-9H-pyrido[2,3-b]indole (1.25 g, 3.9 mmol) After dissolving sodium tert-butoxide (0.48 g, 4.97 mmol) and Tris(dibenzylideneacetone)dipalladium (0 ) (0.065 g, 0.071 mmol) in 50 mL of toluene, tri-tert-butylphosphine (0.03 g, 0.14 mmol) was added and 24 Reflux for an hour and stir. After confirming by HPLC and LC-MASS, the reaction was terminated, and after solvent removal, extraction was performed with MC/H2O. Column (EA: HEX = 1:4), reprecipitation in MC/hexane, vacuum drying, and sublimation purification to obtain 1.2 g of H5 (yield: 53%).

Experimental Example 1: Evaluation of physical properties related to light emission of organic compounds

For the H1 to H5 compounds synthesized in Synthesis Example 1 to Synthesis Example 5, physical properties related to light emission were simulated and evaluated using spartan'10 software. The HOMO energy level (eV), LUMO energy level (eV), band gap energy (eV, LUMO-HOMO), and triplet energy level (E _T , eV) for each organic compound were evaluated, and the evaluation results are shown in the table below. shown in 1.

Evaluation of physical properties of organic compounds compound HOMO (eV) LUMO (eV) Bandgap (eV) E _T (eV) H1 -5.81 -1.98 3.83 2.96 H2 -5.89 -1.56 4.33 2.97 H3 -5.81 -1.98 3.83 2.98 H4 -5.82 -1.96 3.86 3.04 H5 -5.81 -2.0 3.81 3.04

As shown in Table 1, the HOMO energy levels of the organic compounds synthesized according to Synthesis Example 1 to Synthesis Example 5 are shells of quantum dots or quantum rods (eg, ZnSe or ZnS) that can be used as the light emitting material of the light emitting material layer. It has a value between the valence band energy level corresponding to the HOMO energy level of and the HOMO energy level of the hole transport material used in the hole transport layer. In addition, it was confirmed that the energy band gap of the organic compound synthesized according to Synthesis Example 1 to Synthesis Example 5 was larger than that of the core (eg InP) of the inorganic light emitting material.

Therefore, when the organic compound synthesized in Synthesis Example 1 to Synthesis Example 5 is used in the light emitting material layer in combination with the inorganic light emitting material, the HOMO (or valence band) energy level of the light emitting material layer is increased, thereby forming the hole transport layer and the light emitting material layer. Hole injection into the light emitting material layer may be improved by removing the HOMO energy barrier between the layers. In addition, when the organic compound synthesized in Synthesis Example 1 to Synthesis Example 5 is used as a host of the light emitting material layer and an inorganic light emitting material is used in combination as a dopant (guest), it will act advantageously in energy transfer to form excitons. It was also confirmed that it can.

Example 1: Manufacturing of Light-Emitting Diodes

A light emitting diode was manufactured by applying the H2 compound synthesized according to Synthesis Example 2 to the light emitting material layer. The light emitting area of the ITO substrate was patterned to have a size of 3 mm X 3 mm, washed with ozone, and used to fabricate a light emitting diode. After the ITO substrate was subjected to a solution process to the light emitting material layer, it was transferred into a vacuum chamber to deposit an electron transport layer, an electron injection layer, and a cathode thereon. The deposition process was formed by evaporation from a heated boat under a vacuum of about 10 ⁻⁷ Torr. The light emitting layer and the cathode on the ITO substrate were stacked in the following order.

Hole injection layer (HIL, PEDOT: PSS, spin coating (7000 rpm, 60 seconds) followed by heating at 170 ° C for 30 minutes; 150 Å), hole transport layer (HTL, TFB in chlorobenzene (8 mg / ml), spin coating (4000 rpm, 45 seconds) followed by heating at 130 ° C for 30 minutes; 200 Å), light emitting material layer (EML, H2: InP / ZnSe / ZnS (1: 1) in octane (25 mg / ㎖), spin coating (2000 rpm, 45 sec) followed by heating at 70 ° C for 60 min; 200 Å), electron transport layer (ETL, 2-phenyl-9-(3-(2-phenyl-1,10-phenanthrolin-9-yl)phenyl)-1,10 -phenanthroline, 0.6 Å/s at 300 °C; 500 Å), electron injection layer (EIL, LiF, 12 Å), cathode (Al, 800 Å).

After deposition, it was moved from the deposition chamber to a dry box for film formation and subsequently encapsulated using UV curing epoxy and a moisture getter. This light emitting diode has an emission area of 9 mm 2 .

Example 2: Fabrication of light emitting diode

A light emitting diode was manufactured by repeating the procedure of Example 1, except that the H5 compound synthesized according to Synthesis Example 5 was applied to the light emitting material layer.

Comparative Example: Manufacturing of Light-Emitting Diodes

A light emitting diode was manufactured by repeating the procedure of Example 1 except that only inorganic light emitting material quantum dots (InP/ZnSe/ZnS) was used for the light emitting material layer.

Experimental Example 2: Evaluation of Physical Properties of Light-Emitting Diodes

The light emitting diodes manufactured in Examples 1 and 2 and Comparative Example were connected to an external power supply source, and the EL characteristics of all devices manufactured in the present invention were evaluated at room temperature using a constant current supply source (KEITHLEY) and a photometer PR 650. did Specifically, the driving voltage, voltage at maximum luminance, current, current density (mA/cm 2 ), external quantum efficiency (EQE), luminance ( cd/m2) was measured, and the voltage of the light emitting diode, EQE, luminance and color coordinates for emission wavelength (CIEx, CIEy), maximum EL (EL Max, nm) with the current density fixed at 10 J (mA/cm2) ), and full width at half maximum (FWHM, nm) were measured. Table 2 shows the light emitting characteristics of each light emitting diode at driving voltage and maximum luminance, and Table 3 shows the light emitting characteristics of the light emitting diodes in a state where the current density is set to 10 J. In addition, FIGS. 8 and 9 show measurement results of voltage-current density and voltage-luminance for each light emitting diode.

Light emission characteristics at maximum luminance of light emitting diode Sample driving voltage
(V) Max V A J(mA/cm2) EQE cd/㎡ comparative example 5 7 0.04 513.2 1.2 4025 Example 1 4 8 0.05 649.5 2.1 6626 Example 2 4 7 0.03 340.2 3.0 6668

Light Emission Characteristics of Light Emitting Diodes Sample 10J V EQE cd/㎡ CIEx CIEy EL max FWHM comparative example 5.23 2.26 155 0.678 0.317 636 57 Example 1 5.02 4.59 311 0.680 0.317 636 57 Example 2 5.08 5.43 379 0.681 0.317 636 56

As shown in Table 2, compared to a light emitting diode having a light emitting material layer made of only the light emitting material, the maximum luminance of the light emitting diode using the organic compound synthesized according to the present invention in combination with the light emitting material was improved by up to 65.7%, in this case , the current density was improved by up to 26.6%, and the EQE was improved by up to 150%.

In addition, as shown in Table 3, compared to a light emitting diode having a light emitting material layer made of only a light emitting material in a state where the current density is set to 10 J, the light emitting diode using the organic compound synthesized according to the present invention in combination with the light emitting material The driving voltage was reduced by up to 4.2%, EQE was improved by up to 140.3%, and brightness was improved by up to 144.6%. Therefore, it was confirmed that by applying the organic compound synthesized according to the present invention to the light emitting material layer, a light emitting diode and a light emitting device capable of low-voltage driving and significantly improved light emitting efficiency and quantum efficiency could be implemented.

In the above, the present invention has been described based on exemplary embodiments and examples of the present invention, but the present invention is not limited to the technical idea described in the above embodiments and examples. Rather, those skilled in the art to which the present invention belongs can easily make various modifications and changes based on the above-described embodiments and examples. However, it is clear from the appended claims that all of these modifications and changes fall within the scope of the present invention.

100, 200, 400: light emitting diode
110, 210, 410: first electrode 120, 220, 320: second electrode
130, 230, 430: light emitting layer 140: first charge transfer layer (hole transfer layer)
150, 250, 450: light emitting material layer 160: second charge transfer layer (electron transfer layer)
240: first charge transfer layer (electron transfer layer) 260: second charge transfer layer (hole transfer layer)
300: light emitting display device 440: first charge transfer layer
460: second charge transfer layer Tr: driving thin film transistor

Claims (15)

delete delete delete a first electrode and a second electrode facing each other; and
A light emitting layer positioned between the first electrode and the second electrode,
The light emitting layer includes an organic compound represented by Formula 1 below,
The light-emitting layer includes a light-emitting material layer including the organic compound and a light-emitting material such as a quantum dot (QD) or a quantum rod (QR), and the organic compound is used as a host of the light-emitting material layer, The light emitting material is used as a dopant of the light emitting material layer.
Formula 1

(In Formula 1, R ₁ and R ₂ are each independently an unsubstituted or substituted C ₁ ~ C ₂₀ linear or branched alkyl group, an unsubstituted or substituted C ₂ ~ C ₂₀ linear or branched alkenyl group, and an unsubstituted or substituted C ₁ ~ C ₂₀ Selected from the group consisting of alkoxy groups; R ₃ is a C ₈ ~ C ₃₀ fused heteroaryl group having 2 or more heteroatoms, a C ₈ ~C ₃₀ fused heteroaralkyl group having 2 or more heteroatoms, 2 Selected from the group consisting of a C ₈ ~ C ₃₀ fused heteroaryloxy group having at least two heteroatoms and a C ₈ ~C ₃₀ fused heteroaryl amine group having at least 2 heteroatoms; Ar ₁ to Ar ₃ are each independently substituted unsubstituted or substituted C ₅ ~C ₃₀ homoaryl group, unsubstituted or substituted C ₄ ~C ₃₀ heteroaryl group, unsubstituted or substituted C ₅ ~C ₃₀ homoaralkyl group, unsubstituted or substituted C ₄ ~C ₃₀ hetero aralkyl group, unsubstituted or substituted C ₅ ~ C ₃₀ homo araloxy group and unsubstituted or substituted C ₄ ~ C ₃₀ selected from the group consisting of hetero araloxy group)
According to claim 4,
The organic compound is a light emitting diode including an organic compound represented by Formula 2 below.
Formula 2

(In Formula 1, R ₁ to R ₃ are the same as defined in Formula 1; Ar ₄ to Ar ₆ are each independently a phenyl group or a naphthyl group)
According to claim 4,
The organic compound is a light emitting diode including any one organic compound represented by Formula 3 below.
Formula 3

delete delete delete Board;
Located on the substrate, the light emitting diode according to any one of claims 4 to 6; and
A driving element positioned between the substrate and the light emitting diode and connected to the light emitting diode
A light emitting device comprising a.
According to claim 10,
The light emitting device is a light emitting display device. According to claim 4,
The light emitting layer further includes a hole transport layer positioned between the first electrode and the light emitting material layer or between the second electrode and the light emitting material layer,
The hole transport layer is a light emitting diode made of an inorganic material.
According to claim 12,
The inorganic material included in the hole transport layer is NiO, MoO ₃ , Cr ₂ O ₃ , Bi ₂ O ₃ or a metal oxide of p-type ZnO, copper thiocyanate (CuSCN), Mo ₂ S or p-type GaN of non- A light emitting diode selected from the group consisting of inorganic oxides and combinations thereof.
According to claim 4,
Further comprising an electron transport layer positioned between the light emitting material layer and the second electrode or between the first electrode and the light emitting material layer,
The electron transport layer is a light emitting diode made of an inorganic material.
According to claim 14,
The inorganic material included in the electron transport layer may be titanium dioxide (TiO ₂ ), zinc oxide (ZnO), zinc magnesium oxide (ZnMgO) doped or undoped with Al, Mg, In, Li, Ga, Cd, Cs or Cu, Zirconium oxide (ZrO), tin oxide (SnO ₂ ), tungsten oxide (WO ₃ ), tantalum oxide (Ta ₂ O ₃ ), hafnium oxide (HfO ₃ ), aluminum oxide (Al ₂ O ₃ ), zirconium silicon oxide (ZrSiO ₄ ), an inorganic oxide that is barium titanium oxide (BaTiO ₃ ) or barium zirconium oxide (BaZrO ₃ ); semiconductor particles that are CdS, ZnSe or ZnS doped or undoped with Al, Mg, In, Li, Ga, Cd, Cs or Cu; A light emitting diode selected from the group consisting of Si ₃ N ₄ and combinations thereof.

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