Patent Grant
12250876
This application claims priority to and the benefit of Korean Patent Application No. 10-2020-0011356, filed on Jan. 30, 2020, in the Korean Intellectual Property Office, the entire content of which is incorporated herein by reference.
One or more aspects of embodiments of the present disclosure relate to a light-emitting device.
An example light-emitting device includes an anode, a cathode, and an emission layer between the anode and the cathode. When holes provided from the anode and electrons provided from the cathode combine in the emission layer, excitons are produced that may fall from an excited state to the ground state, thereby generating light.
Light-emitting devices may be driven at low voltage, may be configured to have a thin and lightweight design, and may have excellent characteristics in terms of viewing angles, contrast, and/or response speed. Thus, light-emitting devices have been applied to an increasingly wide range of personal portable devices, such as MP3 players, mobile phones, and televisions (TV).
One or more aspects of embodiments of the present disclosure are directed toward a light-emitting device that has no dark spot(s), has excellent lifespan characteristics, and reduced production costs due to a simplified process.
Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments of the disclosure.
One or more example embodiments of the present disclosure provide a light-emitting device including: a first electrode;
In Equation 1, |ELUMO_HIL| and |ELUMO_HTL| refer to absolute values of lowest unoccupied molecular orbital (LUMO) energy levels of the hole injection layer and the hole transport layer, respectively, and
In one embodiment, the first inorganic material may be at least one selected from WO3, MoO3, ZnO, Cu2O, CuO, CoO, Ga2O3, and GeO2.
In one embodiment, the hole transport layer may include at least one second inorganic material selected from WO3, MoO3, ZnO, Cu2O, CuO, CoO, Ga2O3, and GeO2, and the second inorganic material may be different from the first inorganic material.
In one embodiment, the HOMO energy level of the hole transport layer may have an absolute value of 5.15 eV or less.
In one embodiment, the hole injection layer may be an inorganic hole injection layer, and the hole transport layer may be an inorganic hole transport layer.
In one embodiment, the hole transport layer substantially may not include (e.g., may substantially exclude) a p-dopant.
In one embodiment, the hole transport layer, the hole injection layer, and the first electrode may be collectively wet-etched.
In one embodiment, the emission layer may be an inorganic emission layer including at least one selected from quantum dots and a perovskite.
In one embodiment, the emission layer may include quantum dots, each quantum dot having a core-shell structure including a core including a first semiconductor crystal and a shell including a second semiconductor crystal.
In some embodiments, for example, the first semiconductor crystal and the second semiconductor crystal may each independently include a Group 12-Group 16-based compound, a Group 13-Group 15-based compound, a Group 14-Group 16-based compound, a Group 11-Group 13-Group 16-based compound, a Group 11-Group 12-Group 13-Group 16-based compound, or any combination thereof.
In some embodiments, for example, the first semiconductor crystal and the second semiconductor crystal may each independently include InP, InN, InSb, InAs, InAsP, InGaAs, InGaP, ZnS, ZnSe, ZnSeS, ZnTe, ZnTeSe, GaP, GaN, GaSb, GaAs, CuInS, CuInZnS, AgInS2, CdSe, CdS, CdTe, HgSe, HgTe, CdZnSe, CdSeTe, ZnCdSe, In2S3, Ga2S3, PbS, PbSe, PbTe, or any combination thereof.
In some embodiments, for example, the first semiconductor crystal may include InP, InN, InSb, InAs, InAsP, InGaAs, InGaP, ZnS, ZnSe, ZnSeS, ZnTe, ZnTeSe, GaP, GaN, GaSb, GaAs, CuInS, CuInZnS, AgInS2, CdSe, CdS, CdTe, HgSe, HgTe, CdZnSe, CdSeTe, ZnCdSe, or any combination thereof, and the second semiconductor crystal may include ZnSe, ZnS, In2S3, Ga2S3, or any combination thereof.
In some embodiments, for example, the quantum dots may each further include a ligand linked to the shell.
In some embodiments, for example, the ligand may be or include oleic acid, octylamine, decylamine, mercapto-propionic acid, dodecanethiol, 1-octanethiol, thionyl chloride, or any combination thereof.
In one embodiment, the emission layer may be an organic emission layer.
In one embodiment, the electron transport region may include an electron transport layer, and the electron transport layer may include an inorganic material.
In some embodiments, for example, the electron transport layer may include ZnO, TiO2, WO3, SnO2, Mg-doped ZnO (ZnMgO), Al-doped ZnO (AZO), Ga-doped ZnO (GZO), In-doped ZnO (IZO), ZnSiOx (ZSO, 0<x<5), Al-doped TiO2, Ga-doped TiO2, In-doped TiO2, Al-doped WO3, Ga-doped WO3, In-doped WO3, Al-doped SnO2, Ga-doped SnO2, In-doped SnO2, or any combination thereof.
In one embodiment, an electron blocking layer may be further located between the hole transport layer and the emission layer.
In one embodiment, a hole blocking layer may be further located between the emission layer and the electron transport region.
One or more example embodiments of the present disclosure provide a display apparatus including: a thin-film transistor including a source electrode, a drain electrode, and an activation layer; and the light-emitting device, wherein the first electrode of the light-emitting device is electrically connected to one selected from the source electrode and the drain electrode of the thin-film transistor.
The above and other aspects, features, and advantages of certain embodiments of the disclosure will be more apparent from the following description taken in conjunction with the drawings, including:
Reference will now be made in more detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout, and duplicative descriptions thereof may not be provided. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described below, by referring to the drawings, to explain aspects of the present description. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Throughout the disclosure, the expression “at least one of a, b or c” indicates only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof.
The present disclosure can take the form of various embodiments. and can include various transformations thereof, examples of which are illustrated in the drawings and described in the detailed description. Effects and features of the present disclosure, and methods of achieving the same will be clarified by referring to the Examples described in detail with reference to the drawings. However, the present disclosure is not limited to the examples disclosed below, and may be implemented in various forms.
It will be understood that although the terms “first,” “second,” etc. may be used herein to describe various components, these components should not be limited by these terms. These components are only used to distinguish one component from another.
As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, expressions such as “at least one of,” “one of,” and “selected from,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.
It will be further understood that the terms “includes,” “including,” “comprises,” and/or “comprising,” used herein specify the presence of stated features or components, but do not preclude the presence or addition of one or more other features or components. Further, the use of “may” when describing embodiments of the present disclosure refers to “one or more embodiments of the present disclosure”.
In the following embodiments, when various components such as layers, films, regions, plates, etc. are said to be “on” another component, this may include a case in which the layers, films, regions, or plates are “immediately on” the other component, as well as also a case in which additional components are placed therebetween. The sizes of elements in the drawings may be exaggerated for convenience of explanation. In other words, because sizes and thicknesses of components in the drawings are arbitrarily illustrated for convenience of explanation, the following embodiments of the present disclosure are not limited thereto.
In the present disclosure, a highest occupied molecular orbital (HOMO) energy level, a lowest unoccupied molecular orbital (LUMO) energy level, and a work function of a compound or material may be calculated or evaluated using Gaussian 09 with molecular structure optimization by density functional theory (DFT) using a B3LYP functional.
When a layer is described as an “organic layer”, the layer may consist of one or more organic materials, may substantially be formed or composed of one or more organic materials, or may be formed or composed of a mixture of materials in which the organic components total greater than 50%. When a layer is described as an “inorganic layer”, the layer may consist of one or more inorganic materials, may substantially be formed or composed of one or more inorganic materials, or may be formed or composed of a mixture of materials in which the inorganic components total greater than 50%. In some embodiments, an “organic layer” may not be limited to including organic materials, and in some embodiments, the “organic layer” may only include organic materials. Likewise, in some embodiments, an “inorganic layer” may not be limited to including inorganic materials, and in some embodiments, the “inorganic layer” may only include inorganic materials.
[Description of
Hereinafter, a structure of the light-emitting device 100 according to an embodiment of the present disclosure and a method of manufacturing the light-emitting device 100 will be described in connection with
Referring to
|ELUMO_HIL|>|ELUMO_HTL|+0.1 eV Equation 1
|EHOMO_HIL|>|EHOMO_HTL|+0.1 eV. Equation 2
In Equation 1, |ELUMO_HIL| and |ELUMO_HTL| refer to absolute values of the LUMO energy levels of the hole injection layer 131 and the hole transport layer 132, respectively, and, in Equation 2, |EHOMO_HIL| and |EHOMO_HTL| refer to absolute values of the HOMO energy levels of the hole injection layer 131 and the hole transport layer 132, respectively.
Due to the different energy configurations between the hole transport layer 132 and the hole injection layer 131 (e.g., due to the above energy level relationships or characteristics of the hole transport layer 132 and the hole injection layer 131), an increase in driving voltage of the light-emitting device 100 may be suppressed or decreased, compared to a case of the same configuration therebetween (e.g., a case when the hole transport layer 132 and the hole injection layer 131 have the same or a more similar energy level structure).
In one embodiment, the hole transport layer 132 may have a HOMO energy level absolute value of about 5.15 eV or less.
When a first inorganic material included in a hole injection layer 131 has a suitable work function as described above, a hole transport layer 132 having a deep HOMO energy level (e.g., a relatively deep HOMO energy level compared to the hole injection layer 131) may be implemented, enabling improved lifespan characteristics of a light-emitting device 100.
In one embodiment, the hole transport layer 132, the hole injection layer 131, and the first electrode 110 may be collectively wet-etched (e.g., simultaneously or concurrently etched within the same wet process).
In some embodiments, the wet etching may be performed using an etchant including at least one of phosphoric acid, nitric acid, and acetic acid.
In some embodiments, the wet etching may be performed collectively on the layers from the first electrode 110 to the hole transport layer 132 of the light-emitting device 100, and this simplified process may thereby reduce production costs.
First Electrode 110
The first electrode 110 may be formed by depositing and/or sputtering a material for forming the first electrode 110 on the substrate. When the first electrode 110 is an anode, a material for the first electrode 110 may be selected from materials having a high work function to facilitate hole injection.
In
The first electrode 110 may be a reflective electrode, a semi-transmissive electrode, or a transmissive electrode. When the first electrode 110 is a transmissive electrode, the material for forming the first electrode 110 may be selected from indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO2), zinc oxide (ZnO), and any combination thereof, but embodiments of the present disclosure are not limited thereto. In one or more embodiments, when the first electrode 110 is a semi-transmissive electrode or a reflective electrode, the material for forming the first electrode 110 may be selected from magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), and any combination thereof, but embodiments of the present disclosure are not limited thereto.
The first electrode 110 may have a single-layered structure or a multi-layered structure including two or more layers. For example, the first electrode 110 may have a three-layered structure of ITO/Ag/ITO, but the structure of the first electrode 110 is not limited thereto.
Hole Transport Region 130
The hole transport region 130 may have: i) a single-layered structure including a single material, ii) a single-layered structure including a plurality of different materials, or iii) a multi-layered structure having a plurality of layers including a plurality of different materials.
The hole transport region 130 may include, in addition to the hole injection layer 131 and the hole transport layer 132 that are illustrated in
For example, the hole transport region 130 may have a single-layered structure consisting of a single layer consisting of a plurality of different materials, or a multi-layered structure including a hole injection layer 131/hole transport layer 132, a hole injection layer 131/hole transport layer 132/emission auxiliary layer, a hole injection layer 131/emission auxiliary layer, a hole transport layer 132/emission auxiliary layer, or a hole injection layer 131/hole transport layer 132/electron blocking layer, wherein the constituting layers of each structure are sequentially stacked in each stated order, but the structure of the hole transport region 130 is not limited thereto.
As described above, the hole injection layer 131 may include an oxide, that is, a first inorganic material, of at least one selected from tungsten (W), molybdenum (Mo), zinc (Zn), copper (Cu), nickel (Ni), cobalt (Co), gallium (Ga), and germanium (Ge).
In one embodiment, the first inorganic material may be at least one selected from WO3, MoO3, ZnO, Cu2O, CuO, CoO, Ga2O3, and GeO2.
For example, the first inorganic material may be WO3, but is not limited thereto.
In one embodiment, the hole transport layer 132 may include at least one second inorganic material selected from WO3, MoO3, ZnO, Cu2O, CuO, CoO, Ga2O3, and GeO2, and the second inorganic material may be different from the first inorganic material.
For example, the second inorganic material may be MoO3, but is not limited thereto.
In one embodiment, the hole injection layer 131 may be an inorganic hole injection layer, and the hole transport layer 132 may be an inorganic hole transport layer.
In one embodiment, the hole transport layer 132 substantially may not include a p-dopant (e.g., may substantially exclude a p-dopant, or may substantially not be p-doped).
Here, the expression “substantially may not include a p-dopant” denotes that the hole transport layer 132 includes a p-dopant in an amount of 0.1 wt % or less based on a total weight of the hole transport layer 132, for example, 0.01 wt % or less, for example, 0.001 wt % or less.
In addition, the hole transport region 130 may include at least one selected from m-MTDATA, TDATA, 2-TNATA, NPB(NPD), β-NPB, TPD, spiro-TPD, spiro-NPB, methylated-NPB, TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA), polyaniline/dodecylbenzene sulfonic acid (PANI/DBSA), poly(3,4-ethylene dioxythiophene)/poly(4-styrene sulfonate) (PEDOT/PSS), polyaniline/camphor sulfonic acid (PANI/CSA), polyaniline/poly(4-styrene sulfonate) (PANI/PSS), a compound represented by Formula 201, and a compound represented by Formula 202:
In Formulae 201 and 202,
For example, in Formula 202, R201 and R202 may optionally be linked to each other via a single bond, a dimethyl-methylene group, or a diphenyl-methylene group, and R203 and R204 may optionally be linked to each other via a single bond, a dimethyl-methylene group, or a diphenyl-methylene group.
In one embodiment, in Formulae 201 and 202,
In one or more embodiments, xa1 to xa4 may each independently be 0, 1, or 2.
In one or more embodiments, xa5 may be 1, 2, 3, or 4.
In one or more embodiments, R201 to R204 and Q201 may each independently be selected from: a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group; and
In one or more embodiments, at least one of R201 to R203 in Formula 201 may each independently be selected from:
In one or more embodiments, in Formula 202, i) R201 and R202 may be linked to each other via a single bond, and/or ii) R203 and R204 may be linked to each other via a single bond.
In one or more embodiments, R201 to R204 in Formula 202 may be selected from:
In one or more embodiments, the compound represented by Formula 201 may be represented by Formula 201A:
In one or more embodiments, the compound represented by Formula 201 may be represented by Formula 201A(1), but embodiments of the present disclosure are not limited thereto:
In one or more embodiments, the compound represented by Formula 201 may be represented by Formula 201A-1, but embodiments of the present disclosure are not limited thereto:
In one or more embodiments, the compound represented by Formula 202 may be represented by Formula 202A:
In one or more embodiments, the compound represented by Formula 202 may be represented by Formula 202A-1:
In Formulae 201A, 201A(1), 201A-1, 202A, and 202A-1,
The hole transport region 130 may include at least one compound selected from compounds HT1 to HT39, but compounds to be included in the hole transport region 130 are not limited thereto:
For example, the hole transport region 130 may include a metal oxide.
A thickness of the hole transport region 130 may be about 100 Å to about 10,000 Å, for example, about 100 Å to about 1,000 Å. A thickness of the hole injection layer 131 may be about 100 Å to about 9,000 Å, for example, about 100 Å to about 1,000 Å, and a thickness of the hole transport layer 132 may be about 50 Å to about 2,000 Å, for example, about 100 Å to about 1,500 Å. When the thicknesses of the hole transport region 130, the hole injection layer 131, and the hole transport layer 132 are within these ranges, satisfactory hole transporting characteristics may be obtained without a substantial increase in driving voltage.
The emission auxiliary layer may increase light-emission efficiency by compensating for an optical resonance distance of the wavelength of light emitted by an emission layer 150, and the electron blocking layer may block or reduce the flow of electrons from an electron transport region 170. The emission auxiliary layer and the electron blocking layer may each include the materials as described above.
Emission Layer 150
The emission layer 150 may be a single-layered structure, or a structure including two or more stacked layers. For example, the emission layer 150 may be a single-layered structure, or a structure in which two to ten layers are stacked.
The emission layer 150 may be an inorganic emission layer including at least one selected from quantum dots and a perovskite. As used herein, the term “quantum dot” refers to a spherical semiconductor nanomaterial having a size (e.g., average diameter) of several to several hundreds of nm (e.g., 1 nm to 100 nm), which may include a single material, or may include a core including (e.g., consisting of) a first material having a small band gap, and a shell including a second material disposed to surround the core. As used herein, the term “perovskite” refers to a compound having a CaTiO3-like perovskite crystal structure. The perovskite may have the general formula ABX3, where A and B are cations of different elements, and X is an anion (for example, a halide such as fluoride, chloride, bromide, or iodide, or an oxide). In some embodiments, the perovskite may be an inorganic oxide.
The quantum dots 151 in the emission layer 150 (as shown in
The first semiconductor crystal and the second semiconductor crystal may each independently include a Group 12-Group 16-based compound, a Group 13-Group 15-based compound, a Group 14-Group 16-based compound, a Group 11-Group 13-Group 16-based compound, a Group 11-Group 12-Group 13-Group 16-based compound, or any combination thereof.
For example, the first semiconductor crystal and the second semiconductor crystal may each independently include InP, InN, InSb, InAs, InAsP, InGaAs, InGaP, ZnS, ZnSe, ZnSeS, ZnTe, ZnTeSe, GaP, GaN, GaSb, GaAs, CuInS, CuInZnS, AgInS2, CdSe, CdS, CdTe, HgSe, HgTe, CdZnSe, CdSeTe, ZnCdSe, In2S3, Ga2S3, PbS, PbSe, PbTe, or any combination thereof.
For example, the first semiconductor crystal may include InP, InN, InSb, InAs, InAsP, InGaAs, InGaP, ZnS, ZnSe, ZnSeS, ZnTe, ZnTeSe, GaP, GaN, GaSb, GaAs, CuInS, CuInZnS, AgInS2, CdSe, CdS, CdTe, HgSe, HgTe, CdZnSe, CdSeTe, ZnCdSe, or any combination thereof, and the second semiconductor crystal may include ZnSe, ZnS, In2S3, Ga2S3, or any combination thereof.
In some embodiments, the quantum dots 151 may each further include a ligand linked to a shell.
For example, the ligand may be oleic acid, octylamine, decylamine, mercapto-propionic acid, dodecanethiol, 1-octanethiol, thionyl chloride, or any combination thereof.
The quantum dots 151 may be dispersed in a naturally coordinated form in a dispersion medium (such as an organic solvent and/or a polymer resin), and the dispersion medium may be any transparent medium as long as the medium is not deteriorated by light, does not reflect or absorb light, and does not substantially affect wavelength conversion performance of the quantum dots 151. For example, the organic solvent may include at least one of toluene, chloroform, or ethanol, and the polymer resin may include at least one selected from epoxy resin, silicone, polyethylene, and acrylate.
Unlike bulk state materials, quantum dots have a discontinuous band gap energy due to quantum confinement effects. The band gap energy may vary according to the size of the quantum dot, and even in a case where the same quantum dot composition is used, the quantum dot may emit light of a different wavelength when its size is changed. The smaller the quantum dot size (diameter), the greater the band gap energy, and thus the shorter the wavelength of light being emitted. The size of quantum dots may thereby be adjusted to provide light in a desired or suitable wavelength band, for example, by adjusting or changing the growth conditions of the quantum dot nanocrystals. Accordingly, a light-emitting device with high light efficiency and high color purity may be implemented by introducing such quantum dots into the light-emitting device.
Electron Transport Region 170
The electron transport region 170 may include an electron transport layer.
In one embodiment, the electron transport region 170 may include an electron transport layer, and the electron transport layer may include an inorganic material.
For example, the electron transport layer may include ZnO, TiO2, WO3, SnO2, Mg-doped ZnO (ZnMgO), Al-doped ZnO (AZO), Ga-doped ZnO (GZO), In-doped ZnO (IZO), ZnSiOx (ZSO, 0<x<5), Al-doped TiO2, Ga-doped TiO2, In-doped TiO2, Al-doped WO3, Ga-doped WO3, In-doped WO3, Al-doped SnO2, Ga-doped SnO2, In-doped SnO2, or any combination thereof.
In addition, the electron transport region 170 may have i) a single-layered structure consisting of a single layer consisting of a single material, ii) a single-layered structure consisting of a single layer consisting of a plurality of different materials, or iii) a multi-layered structure having a plurality of layers consisting of a plurality of different materials.
The electron transport region 170 may include at least one selected from a buffer layer, a hole blocking layer, an electron control layer, an electron transport layer, and an electron injection layer, but embodiments of the present disclosure are not limited thereto.
For example, the electron transport region 170 may have an electron transport layer/electron injection layer structure, a hole blocking layer/electron transport layer/electron injection layer structure, an electron control layer/electron transport layer/electron injection layer structure, or a buffer layer/electron transport layer/electron injection layer structure, wherein for each structure, constituting layers are sequentially stacked from an emission layer 150 in this stated order. However, embodiments of the structure of the electron transport region 170 are not limited thereto.
The electron transport region 170 (for example, a buffer layer, a hole blocking layer, an electron control layer, or an electron transport layer in the electron transport region 170) may include a metal-free compound containing at least one π-electron-deficient nitrogen-containing ring.
The “π-electron-deficient nitrogen-containing ring” indicates a C1-C60 heterocyclic group having at least one *—N═*′ moiety as a ring-forming moiety.
For example, the “π-electron-deficient nitrogen-containing ring” may be i) a 5-membered to 7-membered heteromonocyclic group having at least one *—N═*′ moiety, ii) a heteropolycyclic group in which two or more 5-membered to 7-membered heteromonocyclic groups each having at least one *—N═*′ moiety are condensed with each other, or iii) a heteropolycyclic group in which at least one of 5-membered to 7-membered heteromonocyclic groups, each having at least one *—N═*′ moiety, is condensed with at least one C5-C60 carbocyclic group.
Non-limiting examples of the π-electron-deficient nitrogen-containing ring include an imidazole ring, a pyrazole ring, a thiazole ring, an isothiazole ring, an oxazole ring, an isoxazole ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, an indazole ring, a purine ring, a quinoline ring, an isoquinoline ring, a benzoquinoline ring, a phthalazine ring, a naphthyridine ring, a quinoxaline ring, a quinazoline ring, a cinnoline ring, a phenanthridine ring, an acridine ring, a phenanthroline ring, a phenazine ring, a benzimidazole ring, an isobenzothiazole ring, a benzoxazole ring, an isobenzoxazole ring, a triazole ring, a tetrazole ring, an oxadiazole ring, a triazine ring, a thiadiazole ring, an imidazopyridine ring, an imidazopyrimidine ring, and an azacarbazole ring, but are not limited thereto.
For example, the electron transport region 170 may include a compound represented by Formula 601:
[Ar601]xe11-[(L601)xe1-R601]xe21. Formula 601
In Formula 601,
In one embodiment, at least one of the xe11 Ar601(s) and the xe21 R601(s) may include the π-electron-deficient nitrogen-containing ring.
In one embodiment, Ar601 in Formula 601 may be selected from:
When xe11 in Formula 601 is 2 or more, two or more Ar601(s) may be linked to each other via a single bond.
In one or more embodiments, Ar601 in Formula 601 may be an anthracene group.
In one or more embodiments, the compound represented by Formula 601 may be represented by Formula 601-1:
In Formula 601-1,
In one embodiment, L601 and L611 to L613 in Formulae 601 and 601-1 may each independently be selected from:
In one or more embodiments, xe1 and xe611 to xe613 in Formulae 601 and 601-1 may each independently be 0, 1, or 2.
In one or more embodiments, R601 and R611 to R613 in Formulae 601 and 601-1 may each independently be selected from:
The electron transport region 170 may include at least one compound selected from Compounds ET1 to ET36, but embodiments of the present disclosure are not limited thereto:
In one or more embodiments, the electron transport region 170 may include at least one compound selected from 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), Alq3, BAlq, 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole (TAZ), tetra-N-phenylbenzidine (TPB), and NTAZ:
The thicknesses of the buffer layer, the hole blocking layer, and the electron control layer may each independently be about 20 Å to about 1,000 Å, for example, about 30 Å to about 300 Å. When the thicknesses of the buffer layer, the hole blocking layer, and the electron control layer are within these ranges, excellent hole blocking characteristics and/or excellent electron control characteristics may be obtained without a substantial increase in driving voltage.
A thickness of the electron transport layer may be about 100 Å to about 1,000 Å, for example, about 150 Å to about 500 Å. When the thickness of the electron transport layer is within the range described above, the electron transport layer may have satisfactory electron transport characteristics without a substantial increase in driving voltage.
The electron transport region 170 (for example, the electron transport layer in the electron transport region 170) may further include, in addition to the materials described above, a metal-containing material.
The metal-containing material may include at least one selected from an alkali metal complex and an alkaline earth-metal complex. A metal ion of the alkali metal complex may be selected from a Li ion, a Na ion, a K ion, a Rb ion, and a Cs ion, and a metal ion of the alkaline earth-metal complex may be selected from a Be ion, a Mg ion, a Ca ion, a Sr ion, and a Ba ion. A ligand coordinated with the metal ion of the alkali metal complex or the alkaline earth-metal complex may be selected from a hydroxy quinoline, a hydroxy isoquinoline, a hydroxy benzoquinoline, a hydroxy acridine, a hydroxy phenanthridine, a hydroxy phenyloxazole, a hydroxy phenylthiazole, a hydroxy phenyloxadiazole, a hydroxy phenylthiadiazole, a hydroxy phenylpyridine, a hydroxy phenylbenzimidazole, a hydroxy phenylbenzothiazole, a bipyridine, a phenanthroline, and a cyclopentadiene, but embodiments of the present disclosure are not limited thereto.
In some embodiments, for example, the metal-containing material may include a Li complex. The Li complex may include, for example, Compound ET-D1 (lithium quinolate, LiQ) or ET-D2:
The electron transport region 170 may include an electron injection layer to facilitate electron injection from the second electrode 190. The electron injection layer may directly contact the second electrode 190.
The electron injection layer may have i) a single-layered structure including (e.g., consisting of) a single material, ii) a single-layered structure including (e.g., consisting of) a plurality of different materials, or iii) a multi-layered structure having a plurality of layers consisting of a plurality of different materials.
The electron injection layer may include an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal compound, an alkaline earth-metal compound, a rare earth metal compound, an alkali metal complex, an alkaline earth-metal complex, a rare earth metal complex, or any combination thereof.
The alkali metal may be selected from Li, Na, K, Rb, and Cs. In one embodiment, the alkali metal may be Li, Na, or Cs. In one or more embodiments, the alkali metal may be Li or Cs, but embodiments of the present disclosure are not limited thereto.
The alkaline earth metal may be selected from Mg, Ca, Sr, and Ba.
The rare earth metal may be selected from scandium (Sc), yttrium (Y), cerium (Ce), terbium (Tb), ytterbium (Yb), and gadolinium (Gd).
The alkali metal compound, the alkaline earth-metal compound, and the rare earth metal compound may each independently be selected from oxides and halides (for example, fluorides, chlorides, bromides, and/or iodides) of the alkali metal, the alkaline earth-metal, and the rare earth metal.
The alkali metal compound may be selected from alkali metal oxides (such as Li2O, Cs2O, and/or K2O), and alkali metal halides (such as LiF, NaF, CsF, KF, LiI, NaI, CsI, KI, and/or RbI). In one embodiment, the alkali metal compound may be selected from LiF, Li2O, NaF, LiI, NaI, CsI, and KI, but embodiments of the present disclosure are not limited thereto.
The alkaline earth-metal compound may be selected from alkaline earth-metal oxides (such as BaO, SrO, CaO, BaxSr1-xO (0<x<1), and/or BaxCa1-xO (0<x<1)). In one embodiment, the alkaline earth-metal compound may be selected from BaO, SrO, and CaO, but embodiments of the present disclosure are not limited thereto.
The rare earth metal compound may be selected from YbF3, ScF3, Sc2O3, Y2O3, Ce2O3, GdF3, and TbF3. In one embodiment, the rare earth metal compound may be selected from YbF3, ScF3, TbF3, YbI3, ScI3, and TbI3, but embodiments of the present disclosure are not limited thereto.
The alkali metal complex, the alkaline earth-metal complex, and the rare earth metal complex may respectively include an ion of the alkali metal, the alkaline earth-metal, and the rare earth metal as described above, and a ligand coordinated with the metal ion of the alkali metal complex, the alkaline earth-metal complex, or the rare earth metal complex may be selected from hydroxy quinoline, hydroxy isoquinoline, hydroxy benzoquinoline, hydroxy acridine, hydroxy phenanthridine, hydroxy phenyloxazole, hydroxy phenylthiazole, hydroxy phenyloxadiazole, hydroxy phenylthiadiazole, hydroxy phenylpyridine, hydroxy phenylbenzimidazole, hydroxy phenylbenzothiazole, bipyridine, phenanthroline, and cyclopentadiene, but embodiments of the present disclosure are not limited thereto.
The electron injection layer may include (e.g., consist of) an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal compound, an alkaline earth-metal compound, a rare earth metal compound, an alkali metal complex, an alkaline earth-metal complex, a rare earth metal complex, or any combination thereof, as described above. In one or more embodiments, the electron injection layer may further include an organic material. When the electron injection layer further includes an organic material, the alkali metal, alkaline earth metal, rare earth metal, alkali metal compound, alkaline earth-metal compound, rare earth metal compound, alkali metal complex, alkaline earth-metal complex, rare earth metal complex, or combination thereof may be substantially homogeneously or non-homogeneously dispersed in a matrix including (e.g., of) the organic material.
A thickness of the electron injection layer may be about 1 Å to about 100 Å, for example, about 3 Å to about 90 Å. When the thickness of the electron injection layer is within the range described above, the electron injection layer may have satisfactory electron injection characteristics without a substantial increase in driving voltage.
Second Electrode 190
As described above, the light-emitting device 100 includes a second electrode 190 facing the first electrode 110. The second electrode 190 may be the same as described above.
For example, the second electrode 190 may be a cathode and a transmissive electrode, and may include or be formed of InSnOx (x>0) (ITO), Ga-doped ZnO (GZO), In-doped ZnO (IZO), Al-doped ZnO (AZO), InZnSnOx (x>0) (IZTO), ZnSnOx (x>0) (ZTO), or any combination thereof.
For example, the second electrode 190 may include a lower electrode and an upper electrode, and the lower electrode and the upper electrode may each independently include InSnOx (x>0) (ITO), Ga-doped ZnO (GZO), In-doped ZnO (IZO), Al-doped ZnO (AZO), InZnSnOx (x>0) (IZTO), ZnSnOx (ZTO), or any combination thereof.
Description of
Referring to
Each of the layers except for the emission layer 250 are the same as described above.
In one embodiment, the emission layer 250 may be an organic emission layer.
The emission layer 250, which is an organic emission layer, is described below.
Emission Layer 250
When the light-emitting device 200 is a full-color light-emitting device, the emission layer 250 may be patterned into a red emission layer, a green emission layer, or a blue emission layer, according to a sub-pixel. In one or more embodiments, the emission layer 250 may have a stacked structure of two or more layers selected from a red emission layer, a green emission layer, and a blue emission layer, in which the two or more layers may contact each other or may be separated from each other. In one or more embodiments, the emission layer may include two or more materials selected from a red light-emitting material, a green light-emitting material, and a blue light-emitting material, in which the two or more materials are mixed with each other in a single layer to emit white light.
The emission layer 250 may include a host and a dopant. The dopant may include at least one of a phosphorescent dopant or a fluorescent dopant.
An amount of the dopant in the emission layer 250 may be about 0.01 parts by weight to about 15 parts by weight based on 100 parts by weight of the host, but embodiments of the present disclosure are not limited thereto.
A thickness of the emission layer 250 may be about 100 Å to about 1,000 Å, for example, about 200 Å to about 600 Å. When the thickness of the emission layer 250 is within the range, excellent luminescence characteristics may be obtained without a substantial increase in driving voltage.
[Host of Emission Layer 250]
In one or more embodiments, the host may include a compound represented by Formula 301:
[Ar301]xb11-[(L301)xb1-R301]xb21. Formula 301
In Formula 301,
In one embodiment, Ar301 in Formula 301 may be selected from:
When xb11 in Formula 301 is two or more, two or more of Ar301(s) may be linked via a single bond.
In one or more embodiments, the compound represented by Formula 301 may be represented by Formula 301-1 or Formula 301-2:
In Formulae 301-1 and 301-2,
For example, L301 to L304 in Formulae 301, 301-1, and 301-2 may each independently be selected from:
In one embodiment, R301 to R304 in Formulae 301, 301-1, and 301-2 may each independently be selected from:
In one or more embodiments, the host may include an alkaline earth metal complex. For example, the host may be selected from a Be complex (for example, Compound H55) and an Mg complex. In some embodiments, the host may be a Zn complex.
The host may include at least one selected from 9,10-di(2-naphthyl)anthracene (ADN), 2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN), 9,10-di-(2-naphthyl)-2-t-butyl-anthracene (TBADN), 4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP), 1,3-di-9-carbazolylbenzene (mCP), 1,3,5-tri(carbazol-9-yl)benzene (TCP), and Compounds H1 to H55, but embodiments of the present disclosure are not limited thereto:
Phosphorescent Dopant Included in the Emission Layer 250
The phosphorescent dopant may include an organometallic complex represented by Formula 401:
In Formulae 401 and 402,
In one embodiment, A401 and A402 in Formula 402 may each independently be selected from a benzene group, a naphthalene group, a fluorene group, a spiro-bifluorene group, an indene group, a pyrrole group, a thiophene group, a furan group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a quinoxaline group, a quinazoline group, a carbazole group, a benzimidazole group, a benzofuran group, a benzothiophene group, an isobenzothiophene group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a dibenzofuran group, and a dibenzothiophene group.
In one or more embodiments, in Formula 402, i) X401 may be nitrogen and X402 may be carbon, or ii) both X401 and X402 may be nitrogen (e.g., simultaneously).
In one or more embodiments, R401 and R402 in Formula 402 may each independently be selected from:
In one or more embodiments, when xc1 in Formula 401 is two or more, the two A401(s) in two or more L401(s) may optionally be linked to each other via X407 (which is a linking group), and the two A402(s) may optionally be linked to each other via X408 (which is a linking group) (see e.g., Compounds PD1 to PD4 and PD7). X407 and X408 may each independently be a single bond, *—C(═O)—*′, *—N(Q413)-*′, *—C(Q413)(Q414)-*′, or *—C(Q413)=C(Q414)-*′ (wherein Q413 and Q414 may each independently be hydrogen, deuterium, a C1-C20 alkyl group, a C1-C20 alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group), but embodiments of the present disclosure are not limited thereto.
L402 in Formula 401 may be a monovalent, divalent, or trivalent organic ligand. For example, L402 may be selected from a halogen, a diketone (for example, acetylacetonate), a carboxylic acid (for example, picolinate), a —C(═O), an isonitrile, a —CN, and a phosphorus-containing material (for example, phosphine or phosphite), but embodiments of the present disclosure are not limited thereto.
In one or more embodiments, the phosphorescent dopant may be selected from, for example, Compounds PD1 to PD25, but embodiments of the present disclosure are not limited thereto:
Fluorescent Dopant in Emission Layer 250
The fluorescent dopant may include an arylamine compound or a styrylamine compound.
The fluorescent dopant may include a compound represented by Formula 501 or Formula 502:
In Formula 501,
In Formula 502,
In one embodiment, in Formula 501 and Formula 502, Ar501 and A501 to A505 may each independently selected from:
In one or more embodiments, L501 to L503 in Formula 501 may each independently be selected from:
In one or more embodiments, R501 to R505 in Formula 501 and Formula 502 may each independently be selected from:
In one or more embodiments, xd4 in Formula 501 may be 2, but embodiments of the present disclosure are not limited thereto.
For example, the fluorescent dopant may be selected from Compounds FD1 to FD22:
In one or more embodiments, the fluorescent dopant may be selected from the following compounds, but embodiments of the present disclosure are not limited thereto:
Hereinbefore, the light-emitting device according to an embodiment has been described in connection with
The layers constituting the light-emitting device may be formed in a set or predetermined region using one or more suitable methods selected from vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) deposition, ink-jet printing, laser-printing, and laser-induced thermal imaging (LITI).
When the layers constituting the light-emitting device are formed by vacuum deposition, the vacuum deposition may be performed at a deposition temperature of about 100° C. to about 500° C., a vacuum degree of about 10−8 torr to about 10−3 torr, and a deposition speed of about 0.01 Å/sec to about 100 Å/sec, depending on the material to be included and the structure of a layer to be formed.
When the layers constituting the light-emitting device are formed by spin coating, the spin coating may be performed at a coating speed of about 2,000 rpm to about 5,000 rpm and at a heat treatment temperature of about 80° C. to 200° C., depending on the material to be included and the structure of a layer to be formed.
Display Apparatus
The light-emitting device may be included in a display apparatus including a thin-film transistor. The thin-film transistor may include a source electrode, a drain electrode, and an activation layer, and any one of the source electrode and the drain electrode may be electrically connected to the first electrode of the light-emitting device.
The thin-film transistor may further include a gate electrode, a gate insulation layer, and/or the like.
The activation layer may include crystalline silicon, amorphous silicon, an organic semiconductor, an oxide semiconductor, and/or the like, but embodiments of the present disclosure are not limited thereto.
The display apparatus may further include a sealing portion for sealing a light-emitting device. The sealing portion may allow an image from a light-emitting device to be implemented and may block outside air and moisture from penetrating into the light-emitting device. The sealing portion may be a sealing substrate including a transparent glass or a plastic substrate. The sealing portion may be a thin film encapsulation layer including a plurality of organic layers and/or a plurality of inorganic layers. When the sealing portion is a thin-film encapsulation layer, the entire flat display apparatus may be flexible.
General Definition of Substituents
The term “C1-C60 alkyl group” as used herein refers to a linear or branched aliphatic saturated hydrocarbon monovalent group having 1 to 60 carbon atoms, and non-limiting examples thereof include a methyl group, an ethyl group, a propyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an isoamyl group, and a hexyl group. The term “C1-C60 alkylene group” as used herein refers to a divalent group having substantially the same structure as the C1-C60 alkyl group.
The term “C2-C60 alkenyl group” as used herein refers to a hydrocarbon group having at least one carbon-carbon double bond in the middle or at the terminus of the C2-C60 alkyl group, and non-limiting examples thereof include an ethenyl group, a propenyl group, and a butenyl group. The term “C2-C60 alkenylene group” as used herein refers to a divalent group having substantially the same structure as the C2-C60 alkenyl group.
The term “C2-C60 alkynyl group” as used herein refers to a hydrocarbon group having at least one carbon-carbon triple bond in the middle or at the terminus of the C2-C60 alkyl group, and non-limiting examples thereof include an ethynyl group, and a propynyl group. The term “C2-C60 alkynylene group” as used herein refers to a divalent group having substantially the same structure as the C2-C60 alkynyl group.
The term “C1-C60 alkoxy group” as used herein refers to a monovalent group represented by -OA101 (wherein A101 is a C1-C60 alkyl group), and non-limiting examples thereof include a methoxy group, an ethoxy group, and an isopropyloxy group.
The term “C3-C10 cycloalkyl group” as used herein refers to a monovalent saturated hydrocarbon monocyclic group having 3 to 10 carbon atoms, and non-limiting examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group. The term “C3-C10 cycloalkylene group” as used herein refers to a divalent group having substantially the same structure as the C3-C10 cycloalkyl group.
The term “C1-C10 heterocycloalkyl group” as used herein refers to a monovalent saturated monocyclic group having at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom and 1 to 10 carbon atoms, and non-limiting examples thereof include a 1,2,3,4-oxatriazolidinyl group, a tetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term “C1-C10 heterocycloalkylene group” as used herein refers to a divalent group having substantially the same structure as the heterocycloalkyl group.
The term “C3-C10 cycloalkenyl group” as used herein refers to a monovalent monocyclic group that has 3 to 10 carbon atoms, and at least one carbon-carbon double bond in the ring thereof, and no aromaticity, and non-limiting examples thereof include a cyclopentenyl group, a cyclohexenyl group, and a cycloheptenyl group. The term “C3-C10 cycloalkenylene group” as used herein refers to a divalent group having substantially the same structure as the C3-C10 cycloalkenyl group.
The term “C1-C10 heterocycloalkenyl group” as used herein refers to a monovalent monocyclic group that has at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom, 1 to 10 carbon atoms, and at least one double bond in its ring. Non-limiting examples of the C1-C10 heterocycloalkenyl group include a 4,5-dihydro-1,2,3,4-oxatriazolyl group, a 2,3-dihydrofuranyl group, and a 2,3-dihydrothiophenyl group. The term “C1-C10 heterocycloalkenylene group” as used herein refers to a divalent group having substantially the same structure as the C1-C10 heterocycloalkenyl group.
The term “C6-C60 aryl group” as used herein refers to a monovalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms, and the term “C6-C60 arylene group” as used herein refers to a divalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms. Non-limiting examples of the C6-C60 aryl group include a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, and a chrysenyl group. When the C6-C60 aryl group and the C6-C60 arylene group each include two or more rings, the two or more rings may be fused to each other.
The term “C1-C60 heteroaryl group” as used herein refers to a monovalent group having a heterocyclic aromatic system that has at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom, in addition to 1 to 60 carbon atoms. The term “C1-C60 heteroarylene group” as used herein refers to a divalent group having a heterocyclic aromatic system that has at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom, in addition to 1 to 60 carbon atoms. Non-limiting examples of the C1-C60 heteroaryl group include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, and an isoquinolinyl group. When the C1-C60 heteroaryl group and the C1-C60 heteroarylene group each include two or more rings, the two or more rings may be condensed with each other.
The term “C6-C60 aryloxy group” as used herein refers to -OA102 (wherein A102 is a C6-C60 aryl group), and the term “C6-C60 arylthio group” as used herein refers to -SA103 (wherein A103 is a C6-C60 aryl group).
The term “monovalent non-aromatic condensed polycyclic group” as used herein refers to a monovalent group having two or more rings condensed with each other, only carbon atoms (for example, 8 to 60 carbon atoms) as ring-forming atoms, and non-aromaticity in its entire molecular structure. A non-limiting example of the monovalent non-aromatic condensed polycyclic group is a fluorenyl group. The term “divalent non-aromatic condensed polycyclic group” as used herein refers to a divalent group having substantially the same structure as the monovalent non-aromatic condensed polycyclic group.
The term “monovalent non-aromatic condensed heteropolycyclic group” as used herein refers to a monovalent group having two or more rings condensed to each other, at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom in addition to carbon atoms (for example, 1 to 60 carbon atoms), and non-aromaticity in its entire molecular structure. A non-limiting example of the monovalent non-aromatic condensed heteropolycyclic group is a carbazolyl group. The term “divalent non-aromatic condensed heteropolycyclic group” as used herein refers to a divalent group having substantially the same structure as the monovalent non-aromatic condensed heteropolycyclic group.
The term “C4-C60 (e.g., C5-C60) carbocyclic group” as used herein refers to a monocyclic or polycyclic group that includes (e.g., consists of) 4 to 60 carbon atoms as ring-forming atom. The term “C4-C60 carbocyclic group” as used herein may be an aromatic carbocyclic group or a non-aromatic carbocyclic group. The C4-C60 carbocyclic group may be a ring (such as benzene), a monovalent group (such as a phenyl group), or a divalent group (such as a phenylene group). In one or more embodiments, depending on the number of substituents connected to the C4-C60 carbocyclic group, the C4-C60 carbocyclic group may be a trivalent group or a quadrivalent group.
The term “C2-C60 (e.g., C1-C60) heterocyclic group” as used herein refers to a group having substantially the same structure as the C4-C60 carbocyclic group, except for including at least one heteroatom selected from N, O, Si, P, and S in addition to carbon (for example, 2 to 60 carbon atoms, or 1 to 60 carbon atoms) as ring-forming atoms.
In the present specification, at least one substituent of the substituted C4-C60 carbocyclic group, the substituted C2-C60 heterocyclic group, the substituted C1-C20 alkylene group, the substituted C2-C20 alkenylene group, the substituted C3-C10 cycloalkylene group, the substituted C1-C10 heterocycloalkylene group, the substituted C3-C10 cycloalkenylene group, the substituted C1-C10 heterocycloalkenylene group, the substituted C6-C60 arylene group, the substituted C1-C60 heteroarylene group, the substituted divalent non-aromatic condensed polycyclic group, the substituted divalent non-aromatic condensed heteropolycyclic group, the substituted C1-C60 alkyl group, the substituted C2-C60 alkenyl group, the substituted C2-C60 alkynyl group, the substituted C1-C60 alkoxy group, the substituted C3-C10 cycloalkyl group, the substituted C1-C10 heterocycloalkyl group, the substituted C3-C10 cycloalkenyl group, the substituted C1-C10 heterocycloalkenyl group, the substituted C6-C60 aryl group, the substituted C6-C60 aryloxy group, the substituted C6-C60 arylthio group, the substituted C1-C60 heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group may be selected from:
The term “Ph” as used herein refers to a phenyl group, the term “Me” as used herein refers to a methyl group, the term “Et” as used herein refers to an ethyl group, the term “tert-Bu” or “But” as used herein refers to a tert-butyl group, and the term “OMe” as used herein refers to a methoxy group.
The term “biphenyl group” as used herein refers to “a phenyl group substituted with a phenyl group”. For example, a “biphenyl group” is a substituted phenyl group having a C6-C60 aryl group as a substituent.
The term “terphenyl group” as used herein refers to “a phenyl group substituted with a biphenyl group”. For example, a “terphenyl group” is a substituted phenyl group having, as a substituent, a C6-C60 aryl group substituted with a C6-C60 aryl group.
*, *′, and *″, as used herein, unless defined otherwise, each refer to a binding site to a neighboring atom in a corresponding formula.
Hereinafter, compounds and light-emitting devices according to example embodiments of the present disclosure will be described in more detail.
As a substrate and an anode, a glass substrate with 15 Ωcm2 (1,200 Å) ITO thereon (manufactured by Corning Inc.) was cut to a size of 50 mm×50 mm×0.7 mm, sonicated using isopropyl alcohol and pure water for 5 minutes each, and then cleaned by ultraviolet irradiation and exposure to ozone for 30 minutes. Then, the resultant glass substrate was loaded onto a vacuum deposition apparatus.
WO3 was vacuum-deposited on the ITO anode to form a hole injection layer having a thickness of 600 Å, and MoO3 was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 300 Å.
mCP and t-DABNA were co-deposited on the hole transport layer to form an emission layer having a thickness of 300 Å.
TPB was deposited on the emission layer to form an electron transport layer having a thickness of 300 Å, and then Yb/AgMg was vacuum-deposited on the electron transport layer to form a cathode, thereby completing the manufacture of a light-emitting device.
As a substrate and an anode, a glass substrate with 15 Ωcm2 (1,200 Å) ITO thereon (manufactured by Corning Inc.) was cut to a size of 50 mm×50 mm×0.7 mm, sonicated using isopropyl alcohol and pure water for 5 minutes each, and then cleaned by ultraviolet irradiation and exposure to ozone for 30 minutes. Then, the resultant glass substrate was loaded onto a vacuum deposition apparatus.
MoO3 was vacuum-deposited on the ITO anode to form a hole injection layer having a thickness of 600 Å, and MoO3 was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 300 Å.
mCP and t-DABNA were co-deposited on the hole transport layer to form an emission layer having a thickness of 300 Å.
TPB was deposited on the emission layer to form an electron transport layer having a thickness of 300 Å, and then Yb/AgMg was vacuum-deposited on the electron transport layer to form a cathode, thereby completing the manufacture of a light-emitting device.
As a substrate and an anode, a glass substrate with 15 Ωcm2 (1,200 Å) ITO thereon (manufactured by Corning Inc.) was cut to a size of 50 mm×50 mm×0.7 mm, sonicated using isopropyl alcohol and pure water for 5 minutes each, and then cleaned by ultraviolet irradiation and exposure to ozone for 30 minutes. Then, the resultant glass substrate was loaded onto a vacuum deposition apparatus.
NiO was vacuum-deposited on the ITO anode to form a hole injection layer having a thickness of 600 Å, and MoO3 was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 300 Å.
mCP and t-DABNA were co-deposited on the hole transport layer to form an emission layer having a thickness of 300 Å.
TPB was deposited on the emission layer to form an electron transport layer having a thickness of 300 Å, and then Yb/AgMg was vacuum-deposited on the electron transport layer to form a cathode, thereby completing the manufacture of a light-emitting device.
As a substrate and an anode, a glass substrate with 15 Ωcm2 (1,200 Å) ITO thereon (manufactured by Corning Inc.) was cut to a size of 50 mm×50 mm×0.7 mm, sonicated using isopropyl alcohol and pure water for 5 minutes each, and then cleaned by ultraviolet irradiation and exposure to ozone for 30 minutes. Then, the resultant glass substrate was loaded onto a vacuum deposition apparatus.
ZnO was vacuum-deposited on the ITO anode to form a hole injection layer having a thickness of 600 Å, and CBP was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 300 Å.
mCP and t-DABNA were co-deposited on the hole transport layer to form an emission layer having a thickness of 300 Å.
TPB was deposited on the emission layer to form an electron transport layer having a thickness of 300 Å, and then Yb/AgMg was vacuum-deposited on the electron transport layer to form a cathode, thereby completing the manufacture of a light-emitting device.
As a substrate and an anode, a glass substrate with 15 Ωcm2 (1,200 Å) ITO thereon (manufactured by Corning Inc.) was cut to a size of 50 mm×50 mm×0.7 mm, sonicated using isopropyl alcohol and pure water for 5 minutes each, and then cleaned by ultraviolet irradiation and exposure to ozone for 30 minutes. Then, the resultant glass substrate was loaded onto a vacuum deposition apparatus.
NiO was vacuum-deposited on the ITO anode to form a hole injection layer having a thickness of 600 Å, and WO3 was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 300 Å.
mCP and t-DABNA were co-deposited on the hole transport layer to form an emission layer having a thickness of 300 Å.
TPB was deposited on the emission layer to form an electron transport layer having a thickness of 300 Å, and then Yb/AgMg was vacuum-deposited on the electron transport layer to form a cathode, thereby completing the manufacture of a light-emitting device.
J-V characteristics, EQE, and lifespan were measured for the light-emitting devices manufactured according to Example 1 and Comparative Examples 1 to 4, and the results are shown in Table 1:
Referring to Table 1, it was confirmed that the light-emitting device manufactured according to Example 1 has a lower driving voltage, higher levels of luminance and luminescence efficiency, and a long lifespan, compared to the light-emitting devices manufactured according to Comparative Examples 1 to 4.
The light-emitting device may have no dark spot and may have excellent lifespan characteristics and reduced production costs, due to a simplified manufacturing process.
As used herein, the terms “substantially,” “about,” and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent deviations in measured or calculated values that would be recognized by those of ordinary skill in the art.
Any numerical range recited herein is intended to include all sub-ranges of the same numerical precision subsumed within the recited range. For example, a range of “1.0 to 10.0” is intended to include all subranges between (and including) the recited minimum value of 1.0 and the recited maximum value of 10.0, that is, having a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as, for example, 2.4 to 7.6. Any maximum numerical limitation recited herein is intended to include all lower numerical limitations subsumed therein and any minimum numerical limitation recited in this specification is intended to include all higher numerical limitations subsumed therein. Accordingly, Applicant reserves the right to amend this specification, including the claims, to expressly recite any sub-range subsumed within the ranges expressly recited herein.
It should be understood that embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments. It will be understood by those of ordinary skill in the art that various changes in form and details may be made to the described embodiments without departing from the spirit and scope as defined by the following claims and equivalents thereof.
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| Number | Date | Country | |
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| 20210249606 A1 | Aug 2021 | US |
