Patent Application
20240040924
This application claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2022-0087079, filed on Jul. 14, 2022, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety.
The disclosure relates to a heterocyclic compound, an organic light-emitting device including the same, and an electronic apparatus including the organic light-emitting device.
Organic light-emitting devices (OLEDs) are self-emissive devices that, as compared with conventional devices, have wide viewing angles, high contrast ratios, short response times, and excellent brightness, driving voltage, and response speed characteristics, and produce full-color images.
OLEDs include an anode, a cathode, and an organic layer between the anode and the cathode and including an emission layer. A hole transport region may be between the anode and the emission layer, and an electron transport region may be between the emission layer and the cathode. Holes provided from the anode may move toward the emission layer through the hole transport region, and electrons provided from the cathode may move toward the emission layer through the electron transport region. The holes and the electrons recombine in the emission layer to produce excitons. The excitons may transition from an excited state to a ground state, thus generating light.
Provided are a heterocyclic compound, an organic light-emitting device including the same, and an electronic apparatus including the organic light-emitting device.
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.
According to an aspect of the disclosure, provided is a heterocyclic compound represented by Formula 1:
According to another aspect of the disclosure, provided is an organic light-emitting device including a first electrode, a second electrode, and an organic layer arranged between the first electrode and the second electrode and including an emission layer, wherein the organic layer comprises the heterocyclic compound.
According to another aspect of the disclosure, an electronic apparatus includes the organic light-emitting device.
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 accompanying drawings, in which:
Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. 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, by referring to the figures, to explain aspects. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” 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 understood that when an element is referred to as being “on” another element, it can be directly on the other element or intervening elements may be present therebetween In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present
It will be understood that, although the terms “first,” “second,” “third” etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, “a first element,” “component,” “region,” “layer” or “section” discussed below could be termed a second element, component, region, layer or section without departing from the teachings herein.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, “a,” “an,” “the,” and “at least one” do not denote a limitation of quantity, and are intended to cover both the singular and plural, unless the context clearly indicates otherwise. For example, “an element” has the same meaning as “at least one element,” unless the context clearly indicates otherwise.
“Or” means “and/or.” As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. It will be further understood that the terms “comprises” and/or “comprising,” or “includes” and/or “including” when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof.
Furthermore, relative terms, such as “lower” or “bottom” and “upper” or “top,” may be used herein to describe one element's relationship to another element as illustrated in the Figures. It will be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures. For example, if the device in one of the figures is turned over, elements described as being on the “lower” side of other elements would then be oriented on “upper” sides of the other elements. The exemplary term “lower,” can therefore, encompasses both an orientation of “lower” and “upper,” depending on the particular orientation of the figure. Similarly, if the device in one of the figures is turned over, elements described as “below” or “beneath” other elements would then be oriented “above” the other elements. The exemplary terms “below” or “beneath” can, therefore, encompass both an orientation of above and below.
“About” or “approximately” as used herein is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with measurement of the particular quantity (i.e., the limitations of the measurement system). For example, “about” can mean within one or more standard deviations, or within ±30%, 20%, 10% or 5% of the stated value.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
Exemplary embodiments are described herein with reference to cross section illustrations that are schematic illustrations of idealized embodiments. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments described herein should not be construed as limited to the particular shapes of regions as illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, a region illustrated or described as flat may, typically, have rough and/or nonlinear features. Moreover, sharp angles that are illustrated may be rounded Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the precise shape of a region and are not intended to limit the scope of the present claims.
A heterocyclic compound according to an embodiment may be represented by Formula 1:
In an embodiment, in Formula 1, A11 to A13 may each independently be a benzene group, a naphthalene group, a phenanthrene group, a furan group, a thiophene group, a pyrrole group, a cyclopentene group, a silole group, a germole group, a benzofuran group, a benzothiophene group, an indole group, an indene group, a benzosilole group, a benzogermole group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, a fluorene group, a dibenzosilole group, or a dibenzogermole group.
In some embodiments, in Formula 1, A11 to A13 may each independently be a benzene group, a naphthalene group, a benzofuran group, a benzothiophene group, an indole group, an indene group, a benzosilole group, or a benzogermole group.
In some embodiments, A11 to A15 in Formula 1 may each independently be a benzene group or a naphthalene group.
In detail, A11 to A13 in Formula 1 may each independently be a benzene group.
In Formula 1, R11 to R13, R141 to R144, R151 to R153, R161 to R164, R171, and R172 may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a substituted or unsubstituted C1-C60 alkyl group, a substituted or unsubstituted C2-C60 alkenyl group, a substituted or unsubstituted C2-C60 alkynyl group, a substituted or unsubstituted C1-C60 alkoxy group, a substituted or unsubstituted C3-C10 cycloalkyl group, a substituted or unsubstituted C1-C10 heterocycloalkyl group, a substituted or unsubstituted C3-C10 cycloalkenyl group, a substituted or unsubstituted C1-C10 heterocycloalkenyl group, a substituted or unsubstituted C6-C60 aryl group, a substituted or unsubstituted C7-C60 alkylaryl group, a substituted or unsubstituted C6-C60 aryloxy group, a substituted or unsubstituted C6-C60 arylthio group, a substituted or unsubstituted C1-C60 heteroaryl group, a substituted or unsubstituted C2-C60 alkyl heteroaryl group, a substituted or unsubstituted C1-C60 heteroaryloxy group, a substituted or unsubstituted C1-C60 heteroarylthio group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q1)(Q2)(Q3), —C(Q1)(Q2)(Q3), —B(Q1)(Q2), —N(Q1)(Q2), —P(Q1)(Q2), —C(═O)(Q1), —S(═O)(Q1), —S(═O)2(Q1), —P(═O)(Q1)(Q2), or —P(═S)(Q1)(Q2), and
Q1 to Q3 may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C1-C60 alkyl group, a C2-C60 alkenyl group, a C2-C60 alkynyl group, a C1-C60 alkoxy group, a C3-C10 cycloalkyl group, a C1-C10 heterocycloalkyl group, a C3-C10 cycloalkenyl group, a C1-C10 heterocycloalkenyl group, a C6-C60 aryl group, a C7-C60 alkylaryl group, a C6-C60 aryloxy group, a C6-C60 arylthio group, a C1-C60 heteroaryl group, a C2-C60 alkyl heteroaryl group, a C1-C60 heteroaryloxy group, a C1-C60 heteroarylthio group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a C1-C6 alkyl group that is substituted with at least one deuterium, —F, cyano group, C1-C60 alkyl group, C6-C60 aryl group, or any combination thereof, or a C6-C60 aryl group that is substituted with deuterium, —F, cyano group, C1-C60 alkyl group, C6-C60 aryl group, or any combination thereof.
In an embodiment, in Formula 1, R11 to R13, R141 to R144, R151 to R153, R161 to R164, R171, and R172 may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C1-C20 alkyl group, a C1-C20 alkenyl group, a C1-C20 alkoxy group, or a C1-C20 alkylthio group;
—Si(Q1)(Q2)(Q3),—C(Q1)(Q2)(Q3),—B(Q1)(Q2), or —N(Q1)(Q2),
In some embodiments, in Formula 1, R11 to R13, R141 to R144, R151 to R153, R161 to R164, R171, and R172 may each independently hydrogen, deuterium, —F, —CH3, —CD3, —CD2H, —CDH2, —CF3, —CF2H, —CFH2, a C2-C10 alkenyl group, a C1-C10 alkoxy group, a C1-C10 alkylthio group, a group represented by one of Formulae 2-1 to 2-6, a group represented by one of Formulae 2-1 to 2-6 in which at least one hydrogen is substituted with deuterium, a group represented by one of Formulae 2-1 to 2-6 in which at least one hydrogen is substituted with —F, a group represented by one of Formulae 9-1 to 9-39, a group represented by one of Formulae 9-1 to 9-39 in which at least one hydrogen is substituted with deuterium, a group represented by one of Formulae 9-1 to 9-39 in which at least one hydrogen is substituted with —F, a group represented by one of Formulae 9-201 to 9-236, a group represented by one of Formulae 9-201 to 9-236 in which at least one hydrogen is substituted with deuterium, a group represented by one of Formulae 9-201 to 9-236 in which at least one hydrogen is substituted with —F, a group represented by one of Formulae 10-1 to 10-130, a group represented by one of Formulae 10-1 to 10-130 in which at least one hydrogen is substituted with deuterium, a group represented by one of Formulae 10-1 to 10-130 in which at least one hydrogen is substituted with —F, a group represented by one of Formulae 10-201 to 10-358, a group represented by one of Formulae 10-201 to 10-358 in which at least one hydrogen is substituted with deuterium, a group represented by one of Formulae 10-201 to 10-358 in which at least one hydrogen is substituted with —F, —N(Q1)(Q2), —Si(Q1)(Q2)(Q3), or —C(Q1)(Q2)(Q3),
In Formulae 9-1 to 9-39, 9-201 to 9-236, 10-1 to 10-130, and 10-201 to 10-358, * indicates a binding site to an adjacent atom, “Ph” represents a phenyl group, “TMS” and “SiMe3” each represent a trimethylsilyl group, and “TMG” and “GeMe3” each represent a trimethylgermyl group.
The “group represented by Formulae 9-1 to 9-39 in which at least one hydrogen is substituted with deuterium” and the “group represented by Formulae 9-201 to 9-236 in which at least one hydrogen is substituted with deuterium” may each be, for example, a group represented by one of Formulae 9-501 to 9-514 and 9-601 to 9-636:
The “group represented by Formulae 9-1 to 9-39 in which at least one hydrogen is substituted with —F” and the “group represented by Formulae 9-201 to 9-236 in which at least one hydrogen is substituted with —F” may each be, for example, a group represented by one of Formulae 9-701 to 9-710:
The “group represented by Formulae 10-1 to 10-130 in which at least one hydrogen is substituted with a deuterium” and the “group represented by Formulae 10-201 to 10-358 in which at least one hydrogen is substituted with deuterium” may each be, for example, a group represented by one of Formulae 10-501 to 576:
The “group represented by Formulae 10-1 to 10-130 in which at least one hydrogen is substituted with —F” and the “group represented by Formulae 10-201 to 10-358 in which at least one hydrogen is substituted with —F” may each be, for example, a group represented by one of Formulae 10-601 to 617:
In an embodiment, in Formula 1, at least one of R11 to R13, R141 to R144, R151 to R153, R161 to R164, R171, and R172 may be a group represented by one of Formulae 2-1 to 2-6 and a group represented by one of Formulae 2-1 to 2-6 in which at least one hydrogen is substituted with deuterium:
In some embodiments, at least one of R151 to R153 in Formula 1 may be a group represented by one of Formulae 2-1 to 2-6 or a group represented by one of Formulae 2-1 to 2-6 in which at least one hydrogen is substituted with deuterium.
In some embodiments, R152 in Formula 1 may be a group represented by one of Formulae 2-1 to 2-6 or a group represented by one of Formulae 2-1 to 2-6 in which at least one hydrogen is substituted with deuterium.
In an embodiment, the heterocyclic compound may be represented by Formula 1-1:
In an embodiment, at least one of R11 to R13, R141 to R144, R151 to R153, R161 to R164, R171, and R172 in Formula 1-1 may be a group represented by one of Formulae 2-1 to 2-6 and a group represented by one of Formulae 2-1 to 2-6 in which at least one hydrogen is substituted with deuterium.
In some embodiments, at least one of R151 to R153 and R161 to R164 in Formula 1-1 may be a group represented by one of Formulae 2-1 to 2-6 and a group represented by one of Formulae 2-1 to 2-6 in which at least one hydrogen is substituted with deuterium.
In some embodiments, at least one of R152 and R162 in Formula 1 may be a group represented by one of Formulae 2-1 to 2-6 and a group represented by one of Formulae 2-1 to 2-6 in which at least one hydrogen is substituted with deuterium.
In an embodiment, the heterocyclic compound may be compounds of Group C:
Since the heterocyclic compound has a rigid structure in which aromatic hydrocarbon rings or heteroaromatic rings are condensed, structural relaxation in an excited state may be suppressed. As a result, the heterocyclic compound may have a narrow width of blue emission spectrum and improved colorimetric purity.
Specifically, in the heterocyclic compound, carbazole is condensed at a specific position in a specific direction, specifically, at the para and meta positions with respect to boron and nitrogen, respectively, so that the LUMO energy level of the heterocyclic compound may be enhanced (LUMO energy level is elevated), and the lowest singlet excitation energy level can be relatively high, which can be more favorable for deep blue light emission.
In addition, since the heterocyclic compound has an asymmetric structure in the core thereof, the emission wavelength can be shortened and may also be finely adjusted, thereby providing an organic light-emitting device with high efficiency and/or long life.
The peak wavelength in the photoluminescence (PL) spectrum of the heterocyclic compound according to an embodiment is not particularly limited and may be about 430 nanometers (nm) or greater. In some embodiments, the peak wavelength may be about 435 nm or greater, about 440 nm or greater, about 500 nm or greater, about 490 nm or greater, or about 480 nm or greater. When the peak wavelength is within any of these ranges, the heterocyclic compound according to an embodiment may be more suitable for blue light emission.
The heterocyclic compound according to one or more embodiments may have a small the full width at half maximum (FWHM) of an emission intensity of a peak having a PL peak wavelength. In some embodiments, FWHM may be about 45 nm or less, about 40 nm or less, or about 35 nm or less. When the FWHM is within any of these ranges, the heterocyclic compound according to an embodiment may have improved colorimetric purity.
The peak wavelength at PL and the FWHM at PL may be measured and/or calculated using a spectrofluorophotometer.
ΔEST (found value) of the heterocyclic compound may be about 0.300 eV or less. In an embodiment, ΔEST (found value) of the heterocyclic compound may be about 0.280 eV or less, or about 0.260 eV or less. Within these ranges, the width of the emission spectrum of the heterocyclic compound may be narrow, and high-efficiency light emission can be obtained.
A highest occupied molecular orbital (HOMO) energy level and lowest unoccupied molecular orbital (LUMO) energy level of some heterocyclic compounds represented by Formula 1 and compounds of Comparative Examples were evaluated using the Gaussian 09 program with the molecular structure optimization obtained by B3LYP/6-31(d,p)/gas-based TD density functional theory (DFT), and results thereof are shown in Table 1. In addition, the S1 energy level and the T1 energy level of some of the heterocyclic compounds represented by Formula 1 and compounds of Comparative Examples were evaluated by referring to delta SCF-based J. Phys. Chem. A 2021, 125, 10373-10378 method. The evaluation results are shown in Table 1.
From Table 1, it may be seen that the heterocyclic compound represented by Formula 1 has characteristics suitable for use in an electronic device, for example, for use as a dopant in an emission layer of an organic light-emitting device. Specifically, the heterocyclic compound represented by Formula 1 may have a relatively high lowest singlet excitation energy level compared to the compounds of Comparative Examples 1 to 14, and thus may be suitable for deep blue light emission.
The synthesis method of the heterocyclic compound according to one or more embodiments is not particularly limited and the heterocyclic compound may be synthesized according to a known synthesis method. In particular, it may be synthesized according to or in view of the method described in the Examples. For example, in the method described in the Examples, the heterocyclic compound according to one or more embodiments may be synthesized through modifications such as changing raw materials and reaction conditions, adding or excluding some processes, or appropriately combining with other known synthesis methods.
The method of identifying a structure of the heterocyclic compound according to one or more embodiments is not particularly limited. The heterocyclic compound containing nitrogen according to one or more embodiments may be identified by a known method, for example, NMR or LC-MS.
In
In
A substrate may be additionally disposed under the first electrode 11 or on the second electrode 19. The substrate may be a conventional substrate used in organic light-emitting devices, e.g., a glass substrate or a transparent plastic substrate, each having excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and water repellency.
The first electrode 11 may be produced by depositing or sputtering, onto the substrate, a material for forming the first electrode 11. The first electrode 11 may be an anode. The material for forming the first electrode 11 may be materials with a high work function for easy hole injection.
The first electrode 11 may be a reflective electrode, a semi-transmissive electrode, or a transmissive electrode. When the first electrode 110 is a transmissive electrode, a material for forming the first electrode 110 may be indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO2), zinc oxide (ZnO), and any combinations thereof, but embodiments are not limited thereto. In some embodiments, when the first electrode 110 is a semi-transmissive electrode or a reflective electrode, as a material for forming the first electrode 110, at least one of magnesium (Mg), silver (Ag), aluminum (A1), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), or any combination thereof may be used, but embodiments are not limited thereto.
The first electrode 11 may have a single-layered structure or a multi-layered structure including a plurality of layers.
Emission layer 15
The emission layer 15 may include a heterocyclic compound of Formula I.
A thickness of the emission layer may be in a range of about 100 Å to about 1,000 Å, for example, about 200 Å to about 600 Å. When the thickness of the emission layer is within these ranges, excellent light-emission characteristics may be obtained without a substantial increase in driving voltage.
In the First Embodiment, the heterocyclic compound may be a fluorescence emitter. According to the First Embodiment, the emission layer may further include a host (hereinafter, referred to as ‘Host A’, and Host A may not be identical to the heterocyclic compound). Host A may be understood by referring to the description of the host material provided herein, but embodiments are not limited thereto. Host A may be a fluorescent host.
A general energy transfer of the Example will be described with reference to
Singlet excitons may be produced from Host A in the emission layer, and singlet excitons produced from Host A may be transferred to a fluorescence emitter through Förster energy transfer (FRET).
A ratio of singlet excitons produced from Host A may be 25%, and thus, 75% of triplet excitons produced from Host A may be fused to one another to be converted into singlet excitons. Thus, efficiency of the organic light-emitting device may be further improved. That is, efficiency of an organic light-emitting device may be further improved by using a triplet-triplet fusion mechanism.
According to the First Embodiment, a ratio of emission components emitted from the heterocyclic compound to the total emission components emitted from the emission layer may be 80% or greater, for example, 90% or greater. In some embodiments, a ratio of emission components emitted from the heterocyclic compound may be 95% or greater to the total emission components emitted from the emission layer.
The heterocyclic compound may emit fluorescence, and the host may not emit light.
In the First Embodiment, when the emission layer further includes Host A, in addition to the heterocyclic compound, an amount of the heterocyclic compound may be 50 parts by weight or less, e.g., 30 parts by weight or less, based on 100 parts by weight of the emission layer, and an amount of Host A in the emission layer may be 50 parts by weight or greater, e.g., 70 parts by weight or greater, based on 100 parts by weight of the emission layer, but embodiments are not limited thereto.
In the First Embodiment, when the emission layer further includes Host A, in addition to the heterocyclic compound, Host A and the heterocyclic compound may satisfy Condition A:
E(HA)S1>ES1 Condition A
Here, E(HA)S1 and ES1 may be evaluated using the DFT method of the Gaussian program, which is structure-optimized at the B3LYP/6-31 G(d,p) level.
In the Second Embodiment, the heterocyclic compound may be a delayed fluorescence emitter. According to the Second Embodiment, the emission layer may further include a host (hereinafter, referred to as ‘Host B’, and Host B may not be identical to the heterocyclic compound). Host B may be understood by referring to the description of the host material provided herein, but embodiments are not limited thereto.
A general energy transfer of the Second Embodiment will be described with reference to
25% of singlet excitons produced from Host B in the emission layer may be transferred to a delayed fluorescence emitter through FRET. In addition, 75% of triplet excitons produced from Host B in the emission layer may be transferred to a delayed fluorescence emitter through Dexter energy transfer. Energy transferred to a triplet state of a delayed fluorescence emitter may undergo RISC to a singlet state. Accordingly, by transferring all the singlet excitons and triplet excitons generated in the emission layer to the heterocyclic compound, an organic light-emitting device having improved efficiency can be obtained.
According to the Second Embodiment, a ratio of emission components emitted from the heterocyclic compound to the total emission components emitted from the emission layer may be 80% or greater, for example, 90% or greater. In some embodiments, a ratio of emission components emitted from the heterocyclic compound may be 95% or greater to the total emission components emitted from the emission layer.
Here, the heterocyclic compound may emit fluorescence and/or delayed fluorescence, and the emission components of the heterocyclic compound may be a total of prompt emission components of the heterocyclic compound and delayed fluorescence components by RISC of the heterocyclic compound. In addition, Host B may not emit light.
In the Second Embodiment, when the emission layer further includes Host B, in addition to the heterocyclic compound, an amount of the heterocyclic compound may be 50 parts by weight or less, e.g., 30 parts by weight or less, based on 100 parts by weight of the emission layer, and an amount of Host B in the emission layer may be 50 parts by weight or greater, e.g., 70 parts by weight or greater, based on 100 parts by weight of the emission layer, but embodiments are not limited thereto.
In the Second Embodiment, when the emission layer further includes Host B, in addition to the heterocyclic compound, Host B and the heterocyclic compound may satisfy Condition B:
E(HB)S1>ES1 Condition B
Here, E(HB)S1 and ES1 may be evaluated using the DFT method of the Gaussian program, which is structure-optimized at the B3LYP/6-31 G(d,p) level.
In the Third Embodiment, the heterocyclic compound may be used as a fluorescence emitter, and the emission layer may include a sensitizer, e.g., a delayed fluorescence sensitizer. In the Third Embodiment, the emission layer may further include a host (hereinafter, the host may be referred to as ‘Host C’, and Host C may not be identical to the heterocyclic compound and the sensitizer) and a sensitizer (hereinafter, the sensitizer may be referred to as ‘Sensitizer A’, and Sensitizer A may not be identical to Host C and the heterocyclic compound). Host C and Sensitizer A may respectively be understood by referring to the description of the host material and the sensitizer material provided herein, but embodiments are not limited thereto.
In the Third Embodiment, a ratio of emission components of the heterocyclic compound may be about 80% or greater, for example, 90% or greater (or for example, 95% or greater) to the total emission components emitted from the emission layer. For example, the heterocyclic compound may emit fluorescence. In addition, Host C and Sensitizer A may not each emit light.
A general energy transfer of the Third Embodiment will be described with reference to
Singlet and triplet excitons may be produced from Host C in the emission layer, and singlet and triplet excitons produced from Host C may be transferred to Sensitizer A and then to the heterocyclic compound through FRET. 25% of singlet excitons produced from Host C may be transferred to Sensitizer A through FRET, and energy of 75% of triplet excitons produced from Host C may be transferred to singlet and triplet states of Sensitizer A. Energy transferred to a triplet state of Sensitizer A may undergo RISC to a singlet state, and then, singlet energy of Sensitizer A may be transferred to the heterocyclic compound through FRET.
Accordingly, by transferring all the singlet excitons and triplet excitons generated in the emission layer to the dopant, an organic light-emitting device having improved efficiency can be obtained. In addition, since an organic light-emitting device can be obtained with significantly reduced energy loss, the lifespan characteristics of the organic light-emitting device can be improved.
In the Third Embodiment, when the emission layer further includes Host C and Sensitizer A, in addition to the heterocyclic compound, Host C and Sensitizer A may satisfy Condition C-1 and/or C-2:
S1(HC)≥S1(SA) Condition C-1
S1(SA)≥S1(HC) Condition C-2
S1(HC), S1(SA), and S1(HC) may be evaluated using the DFT method of the Gaussian program, which is structure-optimized at the B3LYP/6-31 G(d,p) level.
When Host C, Sensitizer A, and the heterocyclic compound satisfy Condition C-1 and/or C-2, FRET from Sensitizer A to the heterocyclic compound may be facilitated, and accordingly, the organic light-emitting device may have improved luminescence efficiency.
In the Fourth Embodiment, the heterocyclic compound may be used as a fluorescence emitter, and the emission layer may include a sensitizer, e.g., a phosphorescence sensitizer. In the Fourth Embodiment, the emission layer may further include a host (hereinafter, the host may be referred to as ‘Host D’, and Host D may not be identical to the heterocyclic compound and the sensitizer) and a sensitizer (hereinafter, the sensitizer may be referred to as ‘Sensitizer B’, and Sensitizer B may not be identical to Host D and the heterocyclic compound). Host D and Sensitizer B may respectively be understood by referring to the description of the host material and the sensitizer material provided herein, but embodiments are not limited thereto.
In the Fourth Embodiment, a ratio of emission components of the heterocyclic compound may be about 80% or greater, for example, about 90% or greater (or for example, about 95% or greater) to the total emission components emitted from the emission layer. For example, the heterocyclic compound may emit fluorescence. In addition, Host D and Sensitizer B may not each emit light.
A general energy transfer of the Fourth Embodiment will be described with reference to
75% of triplet excitons produced from Host D in the emission layer may be transferred to Sensitizer B through Dexter energy transfer, and energy of 25% of singlet excitons produced from Host D may be transferred to singlet and triplet states of Sensitizer B. Energy transferred to a singlet state of Sensitizer B may undergo ISC to a triplet state, and then, triplet energy of Sensitizer B may be transferred to the heterocyclic compound through FRET.
Accordingly, by transferring all the singlet excitons and triplet excitons generated in the emission layer to the dopant, an organic light-emitting device having improved efficiency can be obtained. In addition, since an organic light-emitting device can be obtained with significantly reduced energy loss, the lifespan characteristics of the organic light-emitting device can be improved.
In the Third Embodiment, when the emission layer further includes Host D and Sensitizer B, in addition to the heterocyclic compound, Host D and Sensitizer B may satisfy Condition D-1 and/or D-2:
T1(HD)≥T1(SB) Condition D-1
T1(SB)≥S1(HC) Condition D-2
T1(HD), T1(SB), and S1(HC) may be evaluated using the DFT method of the Gaussian program, which is structure-optimized at the B3LYP/6-31 G(d,p) level.
When Host D, Sensitizer B, and the heterocyclic compound satisfy Condition D-1 and/or D-2, FRET from Sensitizer B to the heterocyclic compound may be facilitated, and accordingly, the organic light-emitting device may have improved luminescence efficiency.
In the Third Embodiment and the Fourth Embodiment, an amount of the sensitizer in the emission layer may be in a range of about 5 percent by weight (wt %) to about 50 wt %, or for example, about 10 wt % to about 30 wt %. When the content is within this range, energy transfer may effectively occur in the emission layer. Thus, the organic light-emitting device may have high efficiency and long lifespan.
In the Third Embodiment and the Fourth Embodiment, an amount of the heterocyclic compound in the emission layer may be in a range of about 0.01 wt % to about 15 wt %, or for example, about 0.05 wt % to about 3 wt %, but embodiments are not limited thereto.
In the Third Embodiment and the Fourth Embodiment, the sensitizer and the heterocyclic compound may further satisfy Condition 5:
0μs<Tdecay(HC)<5μs Condition 5
The decay time of the heterocyclic compound was measured from a time-resolved photoluminescence (TRPL) spectrum at room temperature of a film (hereinafter, referred to as “Film (HC)”) having a thickness of 40 nm formed by vacuum-depositing the host and the heterocyclic compound included in the emission layer on a quartz substrate at a weight ratio of 90:10 at a vacuum pressure of 10-7 torr.
In the Fifth Embodiment, the heterocyclic compound may be used as a delayed fluorescence emitter, and the emission layer may include a sensitizer, e.g., a delayed fluorescence sensitizer. In the Fifth Embodiment, the emission layer may further include a host (hereinafter, the host may be referred to as ‘Host E’, and Host E may not be identical to the heterocyclic compound and the sensitizer) and a sensitizer (hereinafter, the sensitizer may be referred to as ‘Sensitizer C’, and Sensitizer C may not be identical to Host E and the heterocyclic compound). Host E and Sensitizer C may respectively be understood by referring to the description of the host material and the sensitizer material provided herein, but embodiments are not limited thereto.
In the Fifth Embodiment, a ratio of emission components of the heterocyclic compound may be about 80% or greater, for example, about 90% or greater (or for example, about 95% or greater) to the total emission components emitted from the emission layer. In some embodiments, the heterocyclic compound may emit fluorescence and/or delayed fluorescence. In addition, Host E and Sensitizer C may not each emit light.
Here, the heterocyclic compound may emit fluorescence and/or delayed fluorescence, and the emission components of the heterocyclic compound may be a total of prompt emission components of the heterocyclic compound and delayed fluorescence components by RISC of the heterocyclic compound.
The general energy transfer of the Fifth Embodiment will be described with reference to
25% of singlet excitons produced from Host E in the emission layer may be transferred to a singlet state of Sensitizer C through FRET, and energy of 75% of triplet excitons produced from Host E may be transferred to a triplet state of Sensitizer C, and then singlet energy of Sensitizer C may be transferred to the heterocyclic compound through FRET. Subsequently, the triplet energy of Sensitizer C may be transferred to the heterocyclic compound through Dexter energy transfer. Energy transferred to a triplet state of Sensitizer C may undergo RISC to a singlet state. Further, in a case of Sensitizer C, energy of triplet excitons produced from Sensitizer C may undergo reverse transfer to Host E and then to the heterocyclic compound, thus emitting by reverse intersystem transfer.
Accordingly, by transferring all the singlet excitons and triplet excitons generated in the emission layer to the dopant, an organic light-emitting device having improved efficiency can be obtained. In addition, since an organic light-emitting device can be obtained with significantly reduced energy loss, the lifespan characteristics of the organic light-emitting device can be improved.
In the Fifth Embodiment, when the emission layer further includes Host E and Sensitizer C, in addition to the heterocyclic compound, Host E and Sensitizer C may satisfy Condition E-1, E-2, and/or E-3:
S1(HE)≥S1(SC) Condition E-1
S1(SC)≥S1(HC) Condition E-2
T1(SC)≥T1(HC) Condition E-3
S1(HE), S1(SC), S1(HC), T1(SC), and T1(HC) may be evaluated using the DFT method of the Gaussian program, which is structure-optimized at the B3LYP/6-31 G(d,p) level.
When Host E, Sensitizer C, and the heterocyclic compound satisfy Condition E-1, E-2, and/or E-3, Dexter transfer FRET from Sensitizer C to the heterocyclic compound may be facilitated, and accordingly, the organic light-emitting device may have improved luminescence efficiency.
In the Fifth Embodiment, an amount of Sensitizer C in the emission layer may be in a range of about 5 wt % to about 50 wt %, or for example, about 10 wt % to about 30 wt %. When the content is within this range, energy transfer may effectively occur in the emission layer. Thus, the organic light-emitting device may have high efficiency and long lifespan.
In the Fifth Embodiment, an amount of the heterocyclic compound in the emission layer may be in a range of about 0.01 wt % to about 15 wt %, or for example, about 0.05 wt % to about 3 wt %, but embodiments are not limited thereto.
The host may not include a metal atom.
In one or more embodiments, the host may include one kind of host. When the host includes one host, the one host may be a bipolar host, an electron-transporting host, and a hole-transporting host, which will be described later.
In one or more embodiments, the host may include a mixture of two or more different hosts. For example, the host may be a mixture of an electron-transporting host and a hole-transporting host, a mixture of two types of electron-transporting hosts different from each other, or a mixture of two types of hole-transporting hosts different from each other. The electron-transporting host and the hole-transporting host may be understood by referring to the related description to be presented later.
In one or more embodiments, the host may include an electron-transporting host including at least one electron-transporting moiety and a hole-transporting host that is free of an electron-transporting moiety.
The electron-transporting moiety used herein may be a cyano group, a π electron-deficient nitrogen-containing cyclic group, and a group represented by one of the following Formulae:
In one or more embodiments, the electron-transporting host of the emission layer 15 may include at least one of a cyano group, a π electron-deficient nitrogen-containing cyclic group, or any combination thereof.
In one or more embodiments, the electron-transporting host in the emission layer 15 may include at least one cyano group.
In one or more embodiments, the electron-transporting host in the emission layer 15 may include at least one cyano group, at least one π electron deficient nitrogen-containing cyclic group, or any combination thereof.
In one or more embodiments, the host may include an electron-transporting host and a hole-transporting host, wherein the electron-transporting host may include at least one π electron-deficient nitrogen-free cyclic group and at least one electron-transporting moiety, and the hole-transporting host may include at least one π electron-deficient nitrogen-free cyclic group and may not include an electron-transporting moiety.
The term “π electron-deficient nitrogen-containing cyclic group” used herein refers to a cyclic group having at least one *—N═*′ moiety, and for example, may be 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 pyridazine group, a pyrimidine group, an indazole group, a purine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a phthalazine group, a naphthyridine group, a quinoxaline group, a quinazoline group, a cinnoline group, a phenanthridine group, an acridine group, a phenanthroline group, a phenazine group, a benzimidazole group, an isobenzothiazole group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a thiadiazole group, an imidazopyridine group, an imidazopyrimidine group, and an azacarbazole group; and a condensed cyclic group in which two or more π electron-efficient nitrogen-containing cyclic groups are condensed with each other.
Meanwhile, the π electron-deficient nitrogen-free cyclic group may be a benzene group, a heptalene group, an indene group, a naphthalene group, an azulene group, an indacene group, an acenaphthylene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentacene group, a hexacene group, a pentacene group, a rubicene group, a corogen group, an ovalene group, a pyrrole group, an isoindole group, an indole group, a furan group, a thiophene group, a benzofuran group, a benzothiophene group, a benzocarbazole group, a dibenzocarbazole group, a dibenzofuran group, a dibenzothiophene group, a dibenzothiophene sulfone group, a carbazole group, a dibenzosilole group, an indenocarbazole group, an indolocarbazole group, a benzofurocarbazole group, a benzothienocarbazole group, a triindolobenzene group, and a condensed cyclic group of two or more π electron-deficient nitrogen-free cyclic groups, but embodiments are not limited thereto.
In one or more embodiments, the electron-transporting host may be at least one compound represented by Formula E-1, and the hole-transporting host may be a compound represented by Formula H-1, but embodiments are not limited thereto:
[Ar301]xb11-[(L301)xb1-R301]xb21 Formula E-1
In one or more embodiments, the hole-transporting host may be a compound represented by Formula H-1:
—Si(Q404)(Q405)(Q406),
In some embodiments, in Formula E-1, Ar301 and L301 may each independently be a benzene group, a naphthalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, an indenoanthracene group, a dibenzofuran group, a dibenzothiophene 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 pyridazine group, a pyrimidine group, an indazole group, a purine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a phthalazine group, a naphthyridine group, a quinoxaline group, a quinazoline group, a cinnoline group, a phenanthridine group, an acridine group, a phenanthroline group, a phenazine group, a benzimidazole group, an isobenzothiazole group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a thiadiazole group, an imidazopyridine group, an imidazopyrimidine group, or an azacarbazole group, each unsubstituted or substituted with at least one deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C1-C20 alkyl group, a C1-C20 alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a cyano group-containing phenyl group, a cyano group-containing biphenyl group, a cyano group-containing terphenyl group, a cyano group-containing naphthyl group, a pyridinyl group, a phenylpyridinyl group, a diphenylpyridinyl group, a biphenylpyridinyl group, a di(biphenyl)pyridinyl group, a pyrazinyl group, a phenylpyrazinyl group, a diphenylpyrazinyl group, a biphenylpyrazinyl group, a di(biphenyl)pyrazinyl group, a pyridazinyl group, a phenylpyridazinyl group, a diphenylpyridazinyl group, a biphenylpyridazinyl group, a di(biphenyl)pyridazinyl group, a pyrimidinyl group, a phenylpyrimidinyl group, a diphenylpyrimidinyl group, a biphenylpyrimidinyl group, a di(biphenyl)pyrimidinyl group, a triazinyl group, a phenyltriazinyl group, a diphenyltriazinyl group, a biphenyltriazinyl group, a di(biphenyl)triazinyl group, —Si(Q31)(Q32)(Q33), —N(Q31)(Q32), —B(Q31)(Q32), —C(═O)(Q31), —S(═O)2(Q31), —P(═O)(Q31)(Q32), or any combination thereof,
In one or more embodiments, Ar301 may be
Q31 to Q33 are each the same as described above.
In one or more embodiments, L301 may be a group represented by Formulae 5-2, 5-3 and 6-8 to 6-33.
In one or more embodiments, R301 may be a cyano group or a group represented by Formula 7-1 to 7-18, and at least one of Ar402 in the number of xd11 may be a group represented by Formulae 7-1 to 7-18, but embodiments are not limited thereto:
In Formula E-1, at least two Ar301(s) may be identical to or different from each other, and at least two L301(s) may be identical to or different from each other. In Formula H-1, at least two L401(s) may be identical to or different from each other, and at least two Ar402(s) may be identical to or different from each other.
In an embodiment, the electron-transporting host includes i) at least one of a cyano group, a pyrimidine group, a pyrazine group, a triazine group, or any combination thereof, or ii) a triphenylene group, and the hole-transporting host may include a carbazole group.
In one or more embodiments, the electron-transporting host may include at least one cyano group.
In an embodiment, the host may be a fluorescent host, and the fluorescent host may be represented by, for example, one of Formulae FH-1 to FH-4.
In an embodiment, the fluorescent host may be represented by Formula FH-1:
In an embodiment, the fluorescent host may be represented by Formula FH-2:
In an embodiment, the fluorescent host may be represented by Formula FH-3:
In an embodiment, the fluorescent host may be represented by Formula FH-4:
When the host is a mixture of an electron-transporting host and a hole-transporting host, the weight ratio of the electron-transporting host and the hole-transporting host may be 1:9 to 9:1, for example, 2:8 to 8:2, for example, 4:6 to 6:4, for example, 5:5. When the weight ratio of the electron-transporting host and the hole-transporting host satisfies these ranges, the hole-and-electron-transporting balance in the emission layer 15 may be made.
The dopant includes the heterocyclic compound of Formula I.
In an embodiment, the sensitizer may be a phosphorescent sensitizer including at least one metal of a first-row transition metal of the Periodic Table of Elements, a second-row transition metal of the Periodic Table of Elements, a third-row transition metal of the Periodic Table of Elements, or any combination thereof.
In an embodiment, the sensitizer may include at least one metal (M11) a first-row transition metal of the Periodic Table of Elements, a second-row transition metal of the Periodic Table of Elements, and a third-row transition metal of the Periodic Table of Elements, and an organic ligand (L1), and L11 and M11 may form 1, 2, 3, or 4 cyclometalated rings.
In an embodiment, the sensitizer may include an organometallic compound represented by Formula 101:
M11(L11)n11(L12)n12 Formula 101
In an embodiment, the sensitizer may be represented by Formula 101 or 102, and in this case, the sensitizer may be referred to as a delayed fluorescence sensitizer:
In an embodiment, A21 in Formulae 101 and 102 may be a substituted or unsubstituted π electron-deficient nitrogen-free cyclic group.
In an embodiment, the π electron-deficient nitrogen-free cyclic group may be a benzene group, a heptalene group, an indene group, a naphthalene group, an azulene group, an indacene group, an acenaphthylene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentacene group, a hexacene group, a pentacene group, a rubicene group, a corogen group, an ovalene group, a pyrrole group, an isoindole group, an indole group, a furan group, a thiophene group, a benzofuran group, a benzothiophene group, a benzocarbazole group, a dibenzocarbazole group, a dibenzofuran group, a dibenzothiophene group, a dibenzothiophene sulfone group, a carbazole group, a dibenzosilole group, an indenocarbazole group, an indolocarbazole group, a benzofurocarbazole group, a benzothienocarbazole group, a triindolobenzene group; or a condensed cyclic group of two or more π electron-deficient nitrogen-free cyclic groups, but embodiments are not limited thereto.
In an embodiment, in Formulae 101 and 102, D21 may be: —F, a cyano group, or a π electron-deficient nitrogen-containing cyclic group;
In an embodiment, the π electron-deficient nitrogen-free cyclic group is the same as described above.
The term “π electron-deficient nitrogen-containing cyclic group” used herein refers to a cyclic group having at least one *—N═*′ moiety, and, for example, may be 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 pyridazine group, a pyrimidine group, an indazole group, a purine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a phthalazine group, a naphthyridine group, a quinoxaline group, a quinazoline group, a cinnoline group, a phenanthridine group, an acridine group, a phenanthroline group, a phenazine group, a benzimidazole group, an isobenzothiazole group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a thiadiazole group, an imidazopyridine group, an imidazopyrimidine group, an azacarbazole group, or a benzimidazolobenzimidazole group; and a condensed cyclic group in which two or more π electron-deficient nitrogen-containing cyclic groups are condensed with each other.
[Hole Transport Region 12]
The hole transport region 12 may be located between the first electrode 11 and the emission layer 15 of the organic light-emitting device 10.
The hole transport region 12 may have a single-layered structure or a multi-layered structure.
For example, the hole transport region 12 may have a hole injection layer, a hole-transport layer, a hole injection layer/hole-transport layer structure, a hole injection layer/first hole-transport layer/second hole-transport layer structure, a hole-transport layer/interlayer structure, a hole injection layer/hole-transport layer/interlayer structure, a hole-transport layer/electron blocking layer structure, or a hole injection layer/hole-transport layer/electron blocking layer structure, but embodiments are not limited thereto.
The hole transport region 12 may include any compound having hole-transporting properties.
For example, the hole transport region 12 may include an amine-based compound.
In an embodiment, the hole transport region 1 may include at least one a compound represented by Formula 201 to a compound represented by Formula 205, but embodiments are not limited thereto:
For example, L201 to L209 may be a benzene group, a heptalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthylene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentacene group, a hexacene group, a pentacene group, a rubicene group, a corogen group, an ovalene group, a pyrrole group, an isoindole group, an indole group, a furan group, a thiophene group, a benzofuran group, a benzothiophene group, a benzocarbazole group, a dibenzocarbazole group, a dibenzofuran group, a dibenzothiophene group, a dibenzothiophene sulfone group, a carbazole group, a dibenzosilole group, an indenocarbazole group, an indolocarbazole group, a benzofurocarbazole group, a benzothienocarbazole group, and a triindolobenzene group, each unsubstituted or substituted with deuterium, a C1-C10 alkyl group, a C1-C10 alkoxy group, a phenyl group, a naphthyl group, a fluorenyl group, a carbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a triphenylenyl group, a biphenyl group, a terphenyl group, a tetraphenyl group, or —Si(Q11)(Q12)(Q13),
In one or more embodiments, the hole transport region 12 may include a carbazole-containing amine-based compound.
In an embodiment, the hole transport region 12 may include a carbazole-containing amine-based compound and a carbazole-free amine-based compound.
The carbazole-containing amine-based compound may be, for example, a compound represented by Formula 201 including a carbazole group and further including at least one a dibenzofuran group, a dibenzothiophene group, a fluorene group, a spiro-bifluorene group, an indenocarbazole group, an indolocarbazole group, a benzofurocarbazole group, a benzothienocarbazole group, or any combination thereof.
The carbazole-free amine-based compound may be, for example, a compound represented by Formula 201 which do not include a carbazole group and which include at least one a dibenzofuran group, a dibenzothiophene group, a fluorene group, a spiro-bifluorene group, an indenocarbazole group, an indolocarbazole group, a benzofurocarbazole group, a benzothienocarbazole group, or any combination thereof.
In one or more embodiments, the hole transport region 12 may include at least one compound represented by Formulae 201 or 202.
In an embodiment, the hole transport region 12 may include at least one compound represented by Formulae 201-1, 202-1 and 201-2, but embodiments are not limited thereto:
In Formulae 201-1, 202-1, and 201-2, L201 to L203, L205, xa1 to xa3, xa5, R201 and R202 are the same as described herein, and R211 to R213 are each independently hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C1-C20 alkyl group, a C1-C20 alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a phenyl group substituted with a C1-C10 alkyl group, a phenyl group substituted with —F, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a dimethylfluorenyl group, a diphenyl fluorenyl group, a triphenylenyl 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, or a pyridinyl group.
For example, the hole transport region 12 may include at least one of Compounds HT1 to HT39, but embodiments are not limited thereto.
In an embodiment, the hole transport region may include 4,4′-cyclohexylidenebis[N,N-bis(4-methylphenyl)benzenamine] (TAPC), tris(4-carbazoyl-9-ylphenyl)amine (TCTA), or any combination thereof.
In one or more embodiments, hole transport region 12 of the organic light-emitting device 10 may further include a p-dopant. When the hole transport region 12 further includes a p-dopant, the hole transport region 12 may have a matrix (for example, at least one of compounds represented by Formulae 201 to 205) and a p-dopant included in the matrix. The p-dopant may be uniformly or non-uniformly doped in the hole transport region 12.
In an embodiment, the LUMO energy level of the p-dopant may be about −3.5 eV or less.
The p-dopant may include at least one of a quinone derivative, a metal oxide, a cyano group-containing compound, or any combination thereof, but embodiments are not limited thereto.
In an embodiment, the p-dopant may include at least one of:
The hole transport region 12 may have a thickness of about 100 Å to about 10000 Å, for example, about 400 Å to about 2000 Å, and the emission layer 15 may have a thickness of about 100 Å to about 3000 Å, for example, about 300 Å to about 1000 Å. When the thickness of each of the hole transport region 12 and the emission layer 15 is within these ranges described above, satisfactory hole transportation characteristics and/or luminescent characteristics may be obtained without a substantial increase in driving voltage.
[Electron Transport Region 17]
The electron transport region 17 may be placed between the emission layer 15 and the second electrode 19 of the organic light-emitting device 10.
The electron transport region 17 may have a single-layered structure or a multi-layered structure.
For example, the electron transport region 17 may have an electron transport layer, an electron transport layer/electron injection layer structure, a buffer layer/electron transport layer structure, hole blocking layer/electron transport layer structure, a buffer layer/electron transport layer/electron injection layer structure, or a hole blocking layer/electron transport layer/electron injection layer structure, but embodiments are not limited thereto. The electron transport region 17 may further include an electron control layer.
The electron transport region 17 may include known electron-transporting materials.
The electron transport region (for example, a buffer layer, a hole blocking layer, an electron control layer, or an electron transport layer in the electron transport region) may include a metal-free compound containing at least one π electron-deficient nitrogen-containing cyclic group. The π electron-deficient nitrogen-containing cyclic group is the same as described above.
In an embodiment, the electron transport region may include a compound represented by Formula 601:
[Ar601]xe11-[(L601)xe1-R601]xe21 Formula 601
In an embodiment, at least one of Ar601 in the number of xe11 and R601 in the number of xe21 may include a π electron-deficient nitrogen-containing cyclic group.
In an embodiment, ring Ar601 and L601 in Formula 601 may each independently be a benzene group, a naphthalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, an indenoanthracene group, a dibenzofuran group, a dibenzothiophene group, a carbazole 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, an indazole group, a purine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a phthalazine group, a naphthyridine group, a quinoxaline group, a quinazoline group, a cinnoline group, a phenanthridine group, an acridine group, a phenanthroline group, a phenazine group, a benzimidazole group, an isobenzothiazole group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a thiadiazole group, an imidazopyridine group, an imidazopyrimidine group, or an azacarbazole group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C1-C20 alkyl group, a C1-C20 alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, —Si(Q31)(Q32)(Q33), —S(═O)2(Q31), or —P(═O)(Q31)(Q32),
When xe11 in Formula 601 is 2 or more, two or more of 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 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 a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl 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, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, or an azacarbazolyl group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C1-C20 alkyl group, a C1-C20 alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl 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, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolyl group, or any combination thereof, or
—S(═O)2(Q601) or —P(═O)(Q601)(Q602),
The electron transport region may include at least one of Compounds ET1 to ET36, but embodiments are not limited thereto:
In an embodiment, the electron transport region may include at least one of 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), 2,2′,2″-(1,3,5-benzenetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBi), NTAZ, or any combination thereof.
Thicknesses of the buffer layer, the hole blocking layer, and the electron control layer may each independently be in the range of 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 or excellent electron control characteristics may be obtained without a substantial increase in driving voltage.
A thickness of the electron transport layer may be in the range of 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 transporting characteristics without a substantial increase in driving voltage.
The electron transport region 17 (for example, the electron transport layer in the electron transport region 17) may further include, in addition to the materials described above, a metal-containing material.
The metal-containing material may include at least one alkali metal complex, alkaline earth-metal complex, or any combination thereof. The alkali metal complex may include a Li ion, a Na ion, a K ion, a Rb ion, a Cs ion, or any combination thereof and the alkaline earth-metal complex may include a Be ion, a Mg ion, a Ca ion, a Sr ion, a Ba ion, or any combination thereof. A ligand coordinated with the metal ion of the alkali metal complex or the alkaline earth-metal complex may be a hydroxy quinoline, a hydroxy isoquinoline, a hydroxy benzoquinoline, a hydroxy acridine, a hydroxy phenanthridine, a hydroxy phenyloxazole, a hydroxy phenylthiazole, a hydroxy diphenyloxadiazole, a hydroxy diphenylthiadiazole, a hydroxy phenylpyridine, a hydroxy phenylbenzimidazole, a hydroxy phenylbenzothiazole, a bipyridine, a phenanthroline, or a cyclopentadiene, but embodiments are not limited thereto.
In an embodiment, 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 17 may include an electron injection layer that facilitates the injection of electrons from the second electrode 19. The electron injection layer may directly contact the second electrode 19.
The electron injection layer may have i) a single-layered structure including a single layer including a single material, ii) a single-layered structure including a single layer including a plurality of different materials, or iii) a multi-layered structure having a plurality of layers including 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 combinations thereof.
The alkali metal may be Li, Na, K, Rb, or Cs. In an 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 are not limited thereto.
The alkaline earth metal may be Mg, Ca, Sr, or Ba.
The rare earth metal may be Sc, Y, Ce, Tb, Yb, or Gd.
The alkali metal compound, the alkaline earth-metal compound, and the rare earth metal compound may be an oxide and a halide (for example, fluoride, chloride, bromide, or iodide) of the alkali metal, the alkaline earth-metal, and the rare earth metal.
The alkali metal compound may be an alkali metal oxide, such as Li2O, Cs2O, or K2O, or an alkali metal halide, such as LiF, NaF, CsF, KF, LiI, NaI, CsI, or KI. In an embodiment, the alkali metal compound may be LiF, Li2O, NaF, LiI, NaI, CsI, or KI, but embodiments are not limited thereto.
The alkaline earth-metal compound may be an alkaline earth-metal oxide, such as BaO, SrO, CaO, BaxSr1-xO (0<x<1), or BaxCa1-xO (0<x<1). In an embodiment, the alkaline earth-metal compound may be BaO, SrO, or CaO, but embodiments are not limited thereto.
The rare earth metal compound may be YbF3, ScF3, ScO3, Y2O3, Ce2O3, GdF3, or TbF3. In an embodiment, the rare earth metal compound may be YbF3, ScF3, TbF3, YbI3, ScI3, or TbI3, but embodiments are not limited thereto.
The alkali metal complex, the alkaline earth-metal complex, and the rare earth metal complex may include an ion of an alkali metal, an alkaline earth-metal, or a rare earth metal as described above, and a ligand coordinated with a metal ion of the alkali metal complex, the alkaline earth-metal complex, or the rare earth metal complex may be hydroxy quinoline, hydroxy isoquinoline, hydroxy benzoquinoline, hydroxy acridine, hydroxy phenanthridine, hydroxy phenyloxazole, hydroxy phenylthiazole, hydroxy diphenyloxadiazole, hydroxy diphenylthiadiazole, hydroxy phenylpyridine, hydroxy phenylbenzimidazole, hydroxy phenylbenzothiazole, bipyridine, phenanthroline, or cyclopentadiene, but embodiments are not limited thereto.
The electron injection layer may 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 combinations 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, 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 may be homogeneously or non-homogeneously dispersed in a matrix including the organic material.
A thickness of the electron injection layer may be in a range of about 1 Å to about 100 Å, and, for example, about 3 Å to about 90 Å. When the thickness of the electron injection layer is within the ranges described above, satisfactory electron injection characteristics may be obtained without a substantial increase in driving voltage.
[Second Electrode 19]
The second electrode 19 is located on the organic layer 10A having such a structure. The second electrode 19 may be a cathode which is an electron injection electrode, and in this regard, a material for forming the second electrode 19 may be a metal, an alloy, an electrically conductive compound, or a combination thereof, which have a relatively low work function.
The second electrode 19 may include at least one of lithium (Li), silver (Ag), magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), ITO, IZO, or any combination thereof, but embodiments are not limited thereto. The second electrode 19 may be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode.
The second electrode 19 may have a single-layered structure having a single layer or a multi-layered structure including two or more layers.
Hereinbefore, the organic light-emitting device has been described with reference to the figures, but embodiments are not limited thereto.
Description of
The organic light-emitting device 100 of
The first light-emitting unit 151 may include a first emission layer 151-EM, and the second light-emitting unit 152 may include a second emission layer 152-EM. The maximum emission wavelength of light emitted from the first light-emitting unit 151 may be different from the maximum emission wavelength of light emitted from the second light-emitting unit 152. For example, the mixed light including the light emitted from the first light-emitting unit 151 and the light emitted from the second light-emitting unit 152 may be white light, but embodiments are not limited thereto.
The hole transport region 120 is located between the first emission unit 151 and the first electrode 110, and the second emission unit 152 may include the first hole transport region 121 located on the side of the first electrode 110.
An electron transport region 170 is located between the second emission unit 152 and the second electrode 190, and the first emission unit 151 may include a first electron transport region 171 located between the charge generation layer 141 and the first emission layer 151-EM.
The first emission layer 151-EM may include the heterocyclic compound.
The second emission layer 152-EM may include the heterocyclic compound.
The first electrode 110 and the second electrode 190 illustrated in
The first emission layer 151-EM and the second emission layer 152-EM in
The hole transport region 120 and the first hole transport region 121 illustrated in
The electron transport region 170 and the first electron transport region 171 illustrated in
As described above, referring to
[Description of
The organic light-emitting device 200 includes a first electrode 210, a second electrode 290 facing the first electrode 210, and a first emission layer 251 and a second emission layer 252 which are stacked between the first electrode 210 and the second electrode 290.
The maximum emission wavelength of light emitted from the first emission layer 251 may be different from the maximum emission wavelength of light emitted from the second emission layer 252. For example, the mixed light of the light emitted from the first emission layer 251 and the light emitted from the second emission layer 252 may be white light, but embodiments are not limited thereto.
In one or more embodiments, a hole transport region 220 may be located between the first emission layer 251 and the first electrode 210, and an electron transport region 270 may be located between the second emission layer 252 and the second electrode 290.
The first emission layer 251 may include the heterocyclic compound.
The second emission layer 252 may include the heterocyclic compound.
The first electrode 210, the hole transport region 220, and the second electrode 290 illustrated in
The first emission layer 251 and the second emission layer 252 illustrated in
The electron transport region 270 illustrated in
Hereinbefore, referring to
Electronic Apparatus
The organic light-emitting device may be included in various electronic apparatuses.
The electronic apparatus may further include a thin-film transistor in addition to the organic light-emitting device as described above. The thin-film transistor may include a source electrode, a drain electrode, and an activation layer, wherein any one of the source electrode and the drain electrode may be electrically connected to any one of the first electrode and the second electrode of the organic light-emitting device.
Explanation of Terms
The term “C1-C60 alkyl group” as used herein refers to a linear or branched saturated aliphatic hydrocarbon monovalent group having 1 to 60 carbon atoms, and 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 the same structure as the C1-C60 alkyl group.
The term “C1-C60 alkoxy group” used herein refers to a monovalent group represented by —OA101 (wherein A101 is the C1-C60 alkyl group), and examples thereof include a methoxy group, an ethoxy group, and an isopropoxy group.
The term “C2-C60 alkenyl group” as used herein refers to a hydrocarbon group formed by substituting at least one carbon-carbon double bond in the middle or at the terminus of the C2-C60 alkyl group, and 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 the same structure as the C2-C60 alkenyl group.
The term “C2-C60 alkynyl group” as used herein refers to a hydrocarbon group formed by substituting at least one carbon-carbon triple bond in the middle or at the terminus of the C2-C60 alkyl group, and 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 the same structure as the C2-C60 alkynyl 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 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 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 of N, O, P, Si, S, B, Se, Ge, or any combination thereof as a ring-forming atom and 1 to 10 carbon atoms, and non-limiting examples thereof include a tetrahydrofuranyl group and a tetrahydrothiophenyl group. The term “C1-C10 heterocycloalkylene group” as used herein refers to a divalent group having the same structure as the C1-C10 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 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 N, O, P, Si, S, B, Se, Ge, or any combination thereof as a ring-forming atom, 1 to 10 carbon atoms, and at least one carbon-carbon double bond in its ring. Examples of the C1-C10 heterocycloalkenyl group are 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 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. 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 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 N, O, P, Si, S, B, Se, Ge, or any combination thereof as a ring-forming atom, and 1 to 60 carbon atoms. The term “C1-C60 heteroarylene group” as used herein refers to a divalent group having a carbocyclic aromatic system that has at least one heteroatom N, O, P, S, B, Se, Ge, or any combination thereof as a ring-forming atom, and 1 to 60 carbon atoms. 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 C6-C60 heteroaryl group and the C6-C60 heteroarylene group each include two or more rings, the rings may be fused to each other.
The term “C6-C60 aryloxy group” as used herein indicates —OA102 (wherein A102 is the C6-C60 aryl group), and the term “C6-C60 arylthio group” as used herein indicates —SA103 (wherein A103 is the C6-C60 aryl group).
The term “monovalent aromatic condensed polycyclic group” as used herein refers to a monovalent group having two or more rings condensed with each other, including only carbon atoms (for example, the number of carbon atoms may be in a range of 8 to 60) as ring-forming atoms, and having aromaticity in its molecular structure when considered as a whole. The term “divalent aromatic condensed polycyclic group” as used herein refers to a divalent group having the same structure as the monovalent aromatic condensed polycyclic group.
The term “monovalent aromatic condensed heteropolycyclic group” as used herein refers to a monovalent group having at least two rings condensed with each other, including a heteroatom N, O, P, Si, and S as well as carbon atoms (for example, the number of carbon atoms may be in a range of 1 to 60) as ring-forming atoms, and having aromaticity in its molecular structure when considered as a whole. The term “divalent aromatic condensed heteropolycyclic group” as used herein refers to a divalent group having the same structure as the monovalent aromatic condensed heteropolycyclic group.
The term “monovalent non-aromatic condensed polycyclic group” used herein refers to a monovalent group in which two or more rings are condensed with each other, only carbon is used as a ring-forming atom (for example, the number of carbon atoms may be 8 to 60) and the whole molecule is a non-aromaticity group. Examples of the monovalent non-aromatic condensed polycyclic group include a fluorenyl group. The term “divalent non-aromatic condensed polycyclic group” as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed polycyclic group described above.
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, a heteroatom N, O, P, Si, S, B, Se, Ge, or any combination thereof, other than carbon atoms (for example, having 1 to 60 carbon atoms), as a ring-forming atom, and no aromaticity in its entire molecular structure. Examples of the monovalent non-aromatic condensed heteropolycyclic group include a carbazolyl group. The term “divalent non-aromatic condensed heteropolycyclic group” as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed heteropolycyclic group described above.
The term “π electron-depleted nitrogen-containing C1-C60 cyclic group” as used herein refers to a cyclic group having 1 to 60 carbon atoms and including at least one *—N═*′ (wherein * and *′ each indicate a binding site to an adjacent atom) as a ring-forming moiety. For example, the π electron-depleted nitrogen-containing C1-C60 cyclic group may be a) a first ring, b) a condensed ring in which at least two first rings are condensed, or c) a condensed ring in which at least one first ring and at least one second ring are condensed with each other.
The term “π electron-rich C3-C60 cyclic group” as used herein refers to a cyclic group having 3 to 60 carbon atoms and not including at least one *—N═*′ (wherein * and *′ each indicate a binding site to an adjacent atom) as a ring-forming moiety. For example, the π electron-rich C3-C60 cyclic group may be a) a second ring or b) a condensed ring in which at least two second rings are condensed.
The term “C5-C60 carbocyclic group” as used herein refers to a monocyclic or polycyclic group having 5 to 60 carbon atoms, and may be, for example, a) a third ring or b) a condensed ring in which two or more third rings are condensed with each other.
The term “C1-C60 heterocyclic group” as used herein refers to a monocyclic or polycyclic group that has 1 to 60 carbon atoms and includes at least one heteroatom, and may be, for example, a) a fourth ring, b) a condensed ring in which two or more fourth rings are condensed with each other, or c) a condensed ring in which at least one third ring is condensed with at least one fourth ring.
The “first ring” as used herein may be 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 pyridazine group, a pyrimidine group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, or a thiadiazole group.
The “second ring” as used herein may be a benzene group, a cyclopentadiene group, a pyrrole group, a furan group, a thiophene group, or a silole group.
The “third ring” as used herein may be a cyclopentane group, a cyclopentadiene group, an indene group, an adamantane group, a norbornene group, a bicyclo[1.1.1]pentane group, a bicyclo[2.1.1]hexane group, a bicyclo[2.2.1]heptane group (a norbornane group), a bicyclo[2.2.2]octane group, a cyclohexane group, a cyclohexene group, or a benzene group.
The “fourth ring” as used herein may be a furan group, a thiophene group, a pyrrole group, a silole group, an oxazole group, an isoxazole group, an oxadiazole group, an isoxadiazole group, an oxatriazole group, an isoxatriazole group, a thiazole group, an isothiazole group, a thiadiazole group, an isothiadiazole group, a thiatriazole group, an isothiatriazole group, a pyrazole group, an imidazole group, a triazole group, a tetrazole group, an azasilole group, a diazasilole group, a triazasilole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, or a triazine group.
In some embodiments, the π electron-depleted nitrogen-containing C1-C60 cyclic group may be 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 pyridazine group, a pyrimidine group, an indazole group, a purine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a phthalazine group, a naphthyridine group, a quinoxaline group, a benzoquinoxaline group, a quinazoline group, a cinnoline group, a phenanthridine group, an acridine group, a phenanthroline group, a phenazine group, a benzimidazole group, an isobenzothiazole group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a thiadiazole group, an imidazopyridine group, an imidazopyrimidine group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, an azadibenzosilole group, an acridine group, or a pyridopyrazine group:
In some embodiments, the π electron-rich C3-C60 cyclic group may be a benzene group, a heptalene group, an indene group, a naphthalene group, an azulene group, an indacene group, an acenaphthylene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentacene group, a hexacene group, a pentaphene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a furan group, a thiophene group, an isoindole group, an indole group, an indene group, a benzofuran group, a benzothiophene group, a benzosilole group, a naphthopyrrole group, a naphthofuran group, a naphthothiophene group, a naphthosilole group, a benzocarbazole group, a dibenzocarbazole group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, a dibenzosilole group, an indenocarbazole group, an indolocarbazole group, a benzofurocarbazole group, a benzothienocarbazole group, a benzosilolocarbazole group, a triindolobenzene group, a pyrrolophenanthrene group, a furanophenanthrene group, a thienophenanthrene group, a benzonaphthofuran group, a benzonapthothiophene group, an (indolo)phenanthrene group, a (benzofurano)phenanthrene group, or a (benzothieno)phenanthrene group.
For example, the C5-C60 carbocyclic group may be a cyclopentane group, a cyclohexane group, a cyclohexene group, a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a 1,2,3,4-tetrahydronaphthalene group, cyclopentadiene group, an indene group, a fluorene group, a 5,6,7,8-tetrahydroisoquinoline group, a 5,6,7,8-tetrahydroquinoline group, an adamantane group, a norbornane group, or a norbornene group.
For example, the C1-C60 heterocyclic group may be a thiophene group, a furan group, a pyrrole group, a cyclopentadiene group, a silole group, a borole group, a phosphole group, a selenophene group, a germole group, a benzothiophene group, a benzofuran group, an indole group, an indene group, a benzosilole group, a benzoborole group, a benzophosphole group, a benzoselenophene group, a benzogermole group, a dibenzothiophene group, a dibenzofuran group, a carbazole group, a dibenzosilole group, a dibenzoborole group, a dibenzophosphole group, a dibenzoselenophene group, a dibenzogermole group, a dibenzothiophene 5-oxide group, a 9H-fluorene-9-one group, a dibenzothiophene 5,5-dioxide group, an azabenzothiophene group, an azabenzofuran group, an azaindole group, an azaindene group, an azabenzosilole group, an azabenzoborole group, an azabenzophosphole group, an azabenzoselenophene group, an azabenzogermole group, an azadibenzothiophene group, an azadibenzofuran group, an azacarbazole group, an azafluorene group, an azadibenzosilole group, an azadibenzoborole group, an azadibenzophosphole group, an azadibenzoselenophene group, an azadibenzogermole group, an azadibenzothiophene 5-oxide group, an aza-9H-fluorene-9-one group, an azadibenzothiophene 5,5-dioxide group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, or a benzothiadiazole group.
The term “a π electron-deficient nitrogen-containing C1-C60 cyclic group, a π electron-rich C3-C60 cyclic group, a C5-C60 cyclic group, and a C1-C60 heterocyclic group” may be part of a condensed cycle or may be a monovalent, a divalent, a trivalent, a tetravalent, a pentavalent, or a hexavalent group, depending on the formula structure.
As used herein, the number of carbons in each group that is substituted (e.g., C1-C60) excludes the number of carbons in the substituent. For example, a C1-C6 alkyl group can be substituted with a C1-C60 alkyl group. The total number of carbons included in the C1-C60 alkyl group substituted with the C1-C60 alkyl group is not limited to 60 carbons. In addition, more than one C1-C60 alkyl substituent may be present on the C1-C60 alkyl group. This definition is not limited to the C1-C60 alkyl group and applies to all substituted groups that recite a carbon range.
In the present specification, at least one substituent of the substituted C5-C30 carbocyclic group, the substituted C1-C30 heterocyclic 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 aromatic condensed polycyclic group, the substituted monovalent aromatic condensed heteropolycyclic group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group may be:
The term “room temperature” used herein refers to a temperature of about 25° C.
The terms “a biphenyl group, a terphenyl group, and a tetraphenyl group” used herein respectively refer to monovalent groups in which two, three, or four phenyl groups which are linked together via a single bond.
The terms “a cyano-containing phenyl group, a cyano-containing biphenyl group, a cyano-containing terphenyl group, and a cyano-containing tetraphenyl group” used herein respectively refer to a phenyl group, a biphenyl group, a terphenyl group, and a tetraphenyl group, each of which is substituted with at least one cyano group. In “a cyano-containing phenyl group, a cyano-containing biphenyl group, a cyano-containing terphenyl group, and a cyano-containing tetraphenyl group”, a cyano group may be substituted to any position of the corresponding group, and the “cyano-containing phenyl group, the cyano-containing biphenyl group, the cyano-containing terphenyl group, and the cyano-containing tetraphenyl group” may further include substituents other than a cyano group. For example, a phenyl group substituted with a cyano group, and a phenyl group substituted with a cyano group and a methyl group may all belong to “a cyano-containing phenyl group.”
Hereinafter, a compound and an organic light-emitting device according to embodiments are described in detail with reference to Synthesis Examples and Examples.
However, the organic light-emitting device is not limited thereto. The wording “‘B’ was used instead of ‘A’” used in describing Synthesis Examples means that an amount of ‘A’ used was identical to an amount of ‘B’ used, in terms of a molar equivalent.
N1,N1,N3-tri([1,1′-biphenyl]-4-yl)-5-(9H-carbazol-9-yl)-2-chloro-N3-(9-phenyl-9H-carbazol-4-yl)benzene-1,3-diamine (6.4 g, 5.54 mmol) was added to a 50 mL round-bottom flask, and t-Bu-benzene (184 mL) was added thereto in a nitrogen atmosphere. The resultant mixture was cooled to −78° C. by using dry ice and acetone, and then, t-BuLi (11.0 mL, 16.61 mmol) was slowly added and stirred at 60° C. for 2 hours. The temperature was lowered to −78° C., and BBr3 (1.1 mL, 11.07 mmol) was slowly added thereto, followed by 2 hours of stirring at room temperature. The temperature was lowered to 0° C. using an ice water bath, and then, i-Pr2NEt (3.4 mL, 19.38 mmol) was slowly added thereto and stirred at 130° C. for 4 hours. The reaction solution was cooled to 0° C. using an ice water bath, and then, the reaction was terminated with 5% sodium acetate (20 mL), followed by extraction with 100 mL of EtOAc. The organic layer was collected, and then, MgSO4 was added thereto to remove water, and then filtered and concentrated. The concentrated reaction product was purified by silica gel column chromatography (DCM:hexanes=2:8) to obtain Compound 5 (3.21 g) as a yellow solid. The obtained Compound 5 was identified by UPLC-MS (C72H47BN4: 978.99).
Compound 7 (1.1 g) was prepared in the same manner as in Synthesis Example 1, except that N1-(3-(9H-carbazol-9-yl)phenyl)-N3-(9-([1,1′-biphenyl]-3-yl)-9H-carbazol-4-yl)-N1,N3-di([1,1′-biphenyl]-4-yl)-5-(9H-carbazol-9-yl)-2-chlorobenzene-1,3-diamine(4.0 g) was used instead of N1,N1,N3-tri([1,1′-biphenyl]-4-yl)-5-(9H-carbazol-9-yl)-2-chloro-N3-(9-phenyl-9H-carbazol-4-yl)benzene-1,3-diamine. The compound was identified by UPLC-MS (C84H54BN5:1144.42).
Compound 5 was diluted in toluene to a concentration of 1.0×10−5 M, and the photoluminescence (PL) spectrum thereof was measured at room temperature using an ISC PC1 spectrofluorometer equipped with a xenon lamp. The maximum emission wavelength of Compound 5 was 461 nm, and the FWHM thereof was evaluated as 19 nm, confirming suitability for deep blue light emission. In addition, the PL spectrum of Compound 5 is illustrated in
An ITO glass substrate was cut to a size of 50 mm×50 mm×0.5 mm and then, sonicated in acetone isopropyl alcohol and pure water, each for 15 minutes, and then, washed by exposure to ultraviolet (UV) light ozone for 30 minutes.
Then, HAT-CN was deposited on the ITO electrode (anode) on the glass substrate to form a hole injection layer having a thickness of 100 Å, NPB was deposited on the hole injection layer to form a first hole transport layer having a thickness of 500 Å, TCTA was deposited on the first hole transport layer to form a second hole transport layer having a thickness of 50 Å, and mCP was deposited on the second hole transport layer to form an electron blocking layer having a thickness of 50 Å.
A first host (Compound H1), a second host (Compound H2) and an emitter (Compound 5) were co-deposited on the electron-blocking layer to form an emission layer having a thickness of 400 Å. In this regard, the first host and the second host were mixed in a weight ratio of 60:40, and the emitter was adjusted to be 3 wt % based on the total weight of the first host, the second host, and the emitter.
DBFPO was deposited on the emission layer to form a hole blocking layer having a thickness of 100 Å, and then DBFPO and Liq were co-deposited thereon at a weight ratio of 5:5 to form an electron transport layer having a thickness of 300 Å, and then, Liq was deposited on the electron transport layer to form an electron injection layer having a thickness of 10 Å, and Al was deposited on the electron injection layer to form a cathode having a thickness of 1000 Å, thereby completing the manufacture of an organic light-emitting device.
An organic light-emitting device was manufactured in the same manner as Example 1-1, except that Compound 7 was used as the dopant to form the emission layer.
An organic light-emitting device was manufactured in the same manner as in Example 1-1, except that, in forming an emission layer, for use as a dopant, corresponding compounds shown in Table 2 were used.
A glass substrate with an ITO electrode located thereon was cut to a size of 50 mm×50 mm×0.5 mm and then, sonicated in acetone isopropyl alcohol and pure water, each for 15 minutes, and then, washed by exposure to UV ozone for 30 minutes.
Then, HAT-CN was deposited on the ITO electrode (anode) on the glass substrate to form a hole injection layer having a thickness of 100 Å, NPB was deposited on the hole injection layer to form a first hole transport layer having a thickness of 500 Å, TCTA was deposited on the first hole transport layer to form a second hole transport layer having a thickness of 50 Å, and mCP was deposited on the second hole transport layer to form an electron blocking layer having a thickness of 50 Å.
A first host (Compound H1), a second host (Compound H2), a sensitizer (Compound S-1), and an emitter (Compound 1) were co-deposited on the electron blocking layer to form an emission layer having a thickness of 400 Å. At this time, the first host and the second host were mixed at a weight ratio of 60:40, and the amounts of the sensitizer and the emitter were adjusted to be 15 wt % and 1 wt %, respectively, based on the total weight of the first host, the second host, the sensitizer, and the emitter.
DBFPO was deposited on the emission layer to form a hole blocking layer having a thickness of 100 Å, and then DBFPO and Liq were co-deposited thereon at a weight ratio of 5:5 to form an electron transport layer having a thickness of 300 Å, and then, Liq was deposited on the electron transport layer to form an electron injection layer having a thickness of 10 Å, and Al was deposited on the electron injection layer to form a cathode having a thickness of 1000 Å, thereby completing the manufacture of an organic light-emitting device.
An organic light-emitting device was manufactured in the same manner as in Example 1-1, except that, in forming an emission layer, for use as a sensitizer and a dopant, Compound 7 was used.
An organic light-emitting device was manufactured in the same manner as in Example 2-1, except that, in forming an emission layer, for use as a sensitizer and a dopant, the compound shown in Table 3 was used.
The driving voltage, maximum external quantum efficiency, and/or maximum emission wavelength of the organic light-emitting devices manufactured in Examples and Comparative Example above were measured using a current-voltage meter (Keithley 2400) and a luminance meter (Minolta Cs-1000A), and results thereof are shown in Tables 2 and 3.
Referring to Table 2, it can be seen that the organic light-emitting devices of Examples 1-1 and 1-2 are suitable for deep blue light emission and have a low driving voltage compared to the organic light-emitting device of Comparative Example 1-1. In general, it is known that EQE significantly decreases as the wavelength of light emitted from an organic light-emitting device becomes shorter. However, the organic light-emitting device of Example 1-1 showed significantly improved EQE while emitting a shorter wavelength compared to the organic light-emitting device of Comparative Example 1-1, and the organic light-emitting device of Example 1-2 shows a similar level of EQE while emitting significantly shorter wavelength of light compared to the organic light-emitting device of Comparative Example 1-1. Accordingly, it can be seen that the organic light-emitting devices of Examples 1-1 and 1-2 show, compared to the organic light-emitting device of Comparative Example 1-1, further improved EQE within the desired wavelength range compared to the light-emitting device.
Referring to Table 3, it can be seen that the organic light-emitting devices of Examples 2-1 and 2-2 are suitable for deep blue light emission and have a low driving voltage compared to the organic light-emitting device of Comparative Example 1-1.
In addition, referring to Tables 2 and 3, it can be seen that the heterocyclic compound is applicable to all organic light-emitting devices that emit light through various mechanisms.
An organic light-emitting device including the heterocyclic compound may have improved efficiency and/or color purity.
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. While one or more embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2022-0087079 | Jul 2022 | KR | national |
