Patent Application
20240224785
This application claims priority to and the benefit of Korean Patent Application No. 10-2022-0165096, filed on Nov. 30, 2022, in the Korean Intellectual Property Office, and all the benefits accruing therefrom under 35 U.S.C. § 119, the entire content of which is incorporated by reference herein.
The present subject matter relates to an organometallic 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, which have improved characteristics in terms of viewing angles, response time, luminance, driving voltage, and response speed. In addition, OLEDs can produce full-color images.
In an example, an organic light-emitting device may include an anode, a cathode, and an organic layer that is arranged between the anode and the cathode and includes an emission layer. A hole transport region may be arranged between the anode and the emission layer, and an electron transport region may be arranged 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 may then recombine in the emission layer to produce excitons. These excitons may transition from an excited state to the ground state, to thereby generate light.
One or more embodiments include an organometallic 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 detailed description that follows and, in part, will be apparent from the detailed description, or may be learned by practice of the presented exemplary embodiments described in further detail herein.
According to an aspect, there is provided an organometallic compound represented by Formula 1:
M1(L1)n1(L2)n2 Formula 1
wherein, in Formula 1,
wherein, in Formulae 1A and 1B,
According to another aspect, there is provided 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, wherein the organic layer includes an emission layer, and wherein the organic layer further includes at least one of the organometallic compounds represented by Formula 1.
The at least one organometallic compound represented by Formula 1 may be included in the emission layer of the organic layer, and the at least one organometallic compound of Formula 1 included in the emission layer may act as a dopant.
According to still another aspect, there is provided an electronic apparatus including the organic light-emitting device.
The above and other aspects, features, and advantages of certain exemplary embodiments will be more apparent from the following detailed description taken in conjunction with the accompanying drawing, in which the FIGURE is a schematic cross-sectional view of an organic light-emitting device according to one or more embodiments.
Reference will now be made in further detail to exemplary embodiments, examples of which are illustrated in the accompanying drawing, wherein like reference numerals refer to like elements throughout the present detailed description. In this regard, the present exemplary embodiments may have different forms and should not be construed as being limited to the detailed descriptions set forth herein. Accordingly, the exemplary embodiments are merely described in further detail below, and by referring to the FIGURE, to explain certain aspects and features. 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.
The terminology used herein is for the purpose of describing one or more exemplary embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term “or” means “and/or.” 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.
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 of the present embodiments.
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.
It will be understood that when an element is referred to as being “on” another element, it can be directly in contact with 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.
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 general inventive concept 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.
“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%, 5% of the stated value.
Hereinafter, when the work function or the HOMO energy level is referred to be “deep,” “high” or “large,” the work function or the HOMO energy level has a large absolute value based on “0 electron Volts (eV)” of the vacuum level, while when the work function or the HOMO energy level is referred to be “shallow,” “low,” or “small,” the work function or HOMO energy level has a small absolute value based on “0 eV” of the vacuum level.
According to an aspect, there is provided an organometallic compound represented by Formula 1:
M1(L1)n1(L2)n2 Formula 1
wherein M1 in Formula 1 is a transition metal.
In one or more embodiments, M1 in Formula 1 may be a first-row transition metal of the Periodic Table of Elements, a second-row transition metal of the Periodic Table of Elements, or a third-row transition metal of the Periodic Table of Elements.
In one or more embodiments, M1 may be iridium, platinum, osmium, palladium, gold, titanium, zirconium, hafnium, europium, terbium, thulium, or rhodium.
For example, M1 may be iridium, platinum, osmium, palladium, or gold.
In one or more embodiments, M1 may be iridium.
In Formula 1, n1 and n2 are each independently 1 or 2.
In one or more embodiments, a sum of n1 and n2 may be 3.
For example, n1 may be 2, and n2 may be 1.
L1 in Formula 1 is a ligand represented by Formula 1A.
In Formula 1A, X1 is C or N, and X2 is C or N.
A bond between M1 and X1 in Formula 1A may be a covalent bond or a coordinate bond.
A bond between M1 and X2 in Formula 1A may be a covalent bond or a coordinate bond.
In one or more embodiments, X1 may be N, X2 may be C, a bond between X1 and M1 may be a coordinate bond, and a bond between X2 and M1 may be a covalent bond.
In Formula 1A, X11 is C(R11) or N, and X12 is C(R12) or N,
In one or more embodiments, ring CY1 may be i) a first ring, ii) a second ring, iii) a condensed ring group in which at least two first rings are condensed together, iv) a condensed ring group in which at least two second rings are condensed together, or v) a condensed ring group in which at least one first ring and at least one second ring are condensed together,
In one or more embodiments, ring CY1 may be a benzene group, a naphthalene group, a 1,2,3,4-tetrahydronaphthalene group, a phenanthrene 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 benzofuran group, a benzothiophene group, a fluorene group, a carbazole group, a dibenzofuran group, a dibenzothiophene group, a dibenzosilole group, an azafluorene group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, or an azadibenzosilole group.
For example, ring CY1 may be a benzene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, or a triazine group.
In one or more embodiments, a moiety represented by
in Formula 1A may be a group represented by one of Formulae CY(1)-1 to CY(1)-4:
wherein, in Formulae CY(1)-1 to CY(1)-4,
In one or more embodiments, a moiety represented by
in Formula 1A may be a group represented by one of Formulae CY(2)-1 to CY(2)-3:
wherein, in Formulae CY(2)-1 to CY(2)-3,
In one or more embodiments, a moiety represented by
in Formula 1A may be a group represented by one of Formulae CY(2)-11 to CY(2)-22:
wherein, in Formulae CY(2)-11 to CY(2)-22,
In Formula 1A, L10 is a single bond, a substituted or unsubstituted C5-C30 carbocyclic group, or a substituted or unsubstituted C1-C30 heterocyclic group.
In one or more embodiments, L10 may be a single bond, a C3-C10 cycloalkylene group that is unsubstituted or substituted with at least one R10a, a C1-C10 heterocycloalkylene group that is unsubstituted or substituted with at least one R10a, a C3-C10 cycloalkenylene group that is unsubstituted or substituted with at least one R10a, a C1-C10 heterocycloalkenylene group that is unsubstituted or substituted with at least one R10a, a C6-C60 arylene group that is unsubstituted or substituted with at least one R10a, or a C1-C60 heteroarylene group that is unsubstituted or substituted with at least one R10a, and R10a may be as described herein in connection with R1.
In one or more embodiments, L10 may be a single bond, a phenylene group, a naphthalene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, or an isoquinoline group.
In Formula 1A, a10 is an integer from 1 to 3.
R10 in Formula 1A is —F, a substituted C1-C60 alkyl group, a substituted C3-C10 cycloalkyl group, a substituted C6-C60 aryl group, a substituted C1-C60 heteroaryl group, —Si(Q1)(Q2)(Q3), or —Ge(Q1)(Q2)(Q3).
When R10 in Formula 1A is a substituted C1-C60 alkyl group, a substituted C3-C10 cycloalkyl group, a substituted C6-C60 aryl group, or a substituted C1-C60 heteroaryl group, R10 includes at least one fluorine. For example, when R10 is a substituted C1-C60 alkyl group, R10 may include, as a substituent, i) at least one fluorine, or ii) at least one substituent that is substituted with at least one fluorine (for example, —CF3 or the like), and a substituent that does not include fluorine together with the substituent (for example, —CH3, a phenyl group, or the like).
In one or more embodiments, R10 may be —F, —CF3, —CF2H, —CFH2, a C1-C20 alkyl group that is substituted with at least one R10b, a C3-C10 cycloalkyl group that is substituted with at least one R10b, a C6-C60 aryl group that is substituted with at least one R10b, a substituted C1-C60 heteroaryl group that is substituted with at least one R10b, —Si(Q1)(Q2)(Q3), or —Ge(Q1)(Q2)(Q3), and
In one or more embodiments, R10 may be:
wherein, in Formulae 9-1 to 9-61, 9-201 to 9-237, 10-1 to 10-129, and 10-201 to 10-350, indicates a binding site to a neighboring atom, “Ph” is a phenyl group, “TMS” is a trimethylsilyl group, and “TMG” is a trimethylgermyl group.
As used herein, a “group represented by one of Formulae 9-1 to 9-61 in which, in each formula, at least one hydrogen is substituted with —F” and a “group represented by one of Formulae 9-201 to 9-237 in which, in each formula, at least one hydrogen is substituted with —F” may each be, for example, a group represented by one of Formulae 9-101 to 9-114:
As used herein, a “group represented by one of Formulae 10-1 to 10-129 in which at least one hydrogen is substituted with —F” and a “group represented by one of Formulae 10-201 to 10-350 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 10-636:
In one or more embodiments, a moiety represented by
(R1)b10-(L10)a10-*″
in Formula 1A may be —F, —CF3, —CF2H, —CFH2, —Si(Q1)(Q2)(Q3), —Ge(Q1)(Q2)(Q3), or a group represented by one of Formulae R-1 to R-3:
wherein, in Formulae R-1 to R-3,
In one or more embodiments, Q1 to Q3 and Q1a to Q3a may each independently be:
In one or more embodiments, L1 may be a ligand represented by one of Formulae 1A-1 to 1A-3:
wherein, in Formulae 1A-1 to 1A-3,
L2 in Formula 1 is a ligand represented by Formula 1B.
In Formulae 1A and 1B, R1, R10a, R11, R12, R21 to R24, R31 to R33, and R41 to R46 may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, —SF5, 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 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 C1-C60 alkylthio 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 alkyl aryl group, a substituted or unsubstituted C7-C60 aryl alkyl 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 C2-C60 heteroaryl alkyl 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), —Ge(Q1)(Q2)(Q3), —N(Q4)(Q5), —B(Q6)(Q7), —P(Q8)(Q9), or —P(═O)(Q8)(Q9).
In one or more embodiments, R1, R11, R12, R21 to R24, R31 to R33, and R41 to R46 may each independently be:
In one or more embodiments, R1, R11, R12, R21 to R24, R31 to R33, and R41 to R46 may each independently be:
wherein, in Formulae 9-1 to 9-61, 9-201 to 9-237, 10-1 to 10-129, and 10-201 to 10-350, * indicates a binding site to a neighboring atom, “Ph” is a phenyl group, “TMS” is a trimethylsilyl group, and “TMG” is a trimethylgermyl group.
b1 in Formulae 1A and 1B is an integer from 0 to 10.
Each of * and *′ in Formulae 1A and 1B indicates a binding site to M1 in Formula 1.
In one or more embodiments, the organometallic compound may be represented by one of Formulae 5-1 to 5-3:
wherein, in Formulae 5-1 to 5-3,
In one or more embodiments, the organometallic compound may be represented by one of Compounds 1 to 124:
In one or more embodiments, the organometallic compound may be electrically neutral.
The organometallic compound represented by Formula 1 includes at least one ligand represented by Formula 1A and at least one ligand represented by Formula 1B. The ligand represented by Formula 1A may control conjugation and wavelength of the compound and improve lifespan and efficiency of a light-emitting device including the organometallic compound, by introducing carbon (C), silicon (Si), or germanium (Ge) into Y1 and/or introducing a substituent such as (L10)a10-(R10)b10.
Therefore, an electronic device, for example, an organic light-emitting device, including the organometallic compound represented by Formula 1 may have a low driving voltage, a low roll-off ratio, a low full width at half maximum (FWHM), and high maximum external quantum efficiency characteristics.
A highest occupied molecular orbital (HOMO) energy level, lowest unoccupied molecular orbital (LUMO) energy level, triplet (T1) energy level, and singlet (S1) energy level of selected organometallic compounds represented by Formula 1 were calculated using a density functional theory (DFT) method of the Gaussian 09 program with the molecular structure optimized at the B3LYP level, and results thereof are shown in Table 1. The energy levels are expressed in electron volts (eV).
From Table 1, it was confirmed that the organometallic compounds represented by Formula 1 had electric characteristics that are suitable for use as a dopant of an electronic device, for example, an organic light-emitting device.
In one or more embodiments, a maximum emission wavelength (emission peak wavelength, λmax) of an emission peak in an emission spectrum or electroluminescence (EL) spectrum of the organometallic compound represented by Formula 1 may be about 580 nanometers (nm) to about 650 nm. For example, a maximum emission wavelength of an emission peak in an emission spectrum or electroluminescence spectrum of the organometallic compound represented by Formula 1 may be about 590 nm to about 650 nm, about 580 nm to about 640 nm, about 600 nm to about 650 nm, or about 600 nm to about 640 nm.
A method of synthesizing the organometallic compound represented by Formula 1 may be apparent to one of ordinary skill in the art and by referring to Synthesis Examples provided herein.
The organometallic compound represented by Formula 1 may be suitable for use as a dopant in an organic layer of an organic light-emitting device, for example, an emission layer of the organic layer. Therefore, according to one or more aspects, there is provided 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, wherein the organic layer includes an emission layer, and wherein the organic layer further includes at least one of the organometallic compounds represented by Formula 1.
The organic light-emitting device may include an organic layer including at least one of the organometallic compounds represented by Formula 1. Thus, the organic light-emitting device may have an excellent driving voltage, an excellent current efficiency, an excellent external quantum efficiency, an excellent roll-off ratio, a relatively narrow FWHM of an emission peak in an EL spectrum, and excellent lifespan characteristics.
The organometallic compound represented by Formula 1 may be used between a pair of electrodes of the organic light-emitting device. For example, at least one of the organometallic compounds represented by Formula 1 may be included in the emission layer. In this regard, the organometallic compound represented by Formula 1 may act as a dopant, and the emission layer may further include a host (that is, an amount of the at least one of the organometallic compounds represented by Formula 1 in the emission layer may be less than that of the host in the emission layer, based on weight). In one or more embodiments, an amount of the host in the emission layer may be greater than an amount of the at least one of the organometallic compounds represented by Formula 1 in the emission layer, based on weight.
In one or more embodiments, the emission layer may emit a red light. For example, the emission layer may emit a red light having a maximum emission wavelength of about 580 nm to about 650 nm. For example, the emission layer may emit a red light having a maximum emission wavelength of about 590 nm to about 650 nm, about 580 nm to about 640 nm, about 600 nm to about 650 nm, or about 600 nm to about 640 nm.
The expression “(organic layer) includes at least one of the organometallic compound represented by Formula 1” as utilized herein may be to mean that the (organic layer) may include one kind of organometallic compound represented by Formula 1 or two or more different kinds of organometallic compounds, each represented by Formula 1.
For example, the organic layer may include Compound 1 only as the at least one of the organometallic compounds represented by Formula 1. In this regard, Compound 1 may be present in the emission layer of the organic light-emitting device. In one or more embodiments, the organic layer may include, as the at least one organometallic compound represented by Formula 1, Compound 1 and Compound 2. In this regard, Compound 1 and Compound 2 may be present in the same layer (for example, both Compound 1 and Compound 2 may be present in the emission layer).
The first electrode may be an anode which is a hole injection electrode, and the second electrode may be a cathode which is an electron injection electrode, or the first electrode may be a cathode which is an electron injection electrode, and the second electrode may be an anode which is a hole injection electrode.
For example, in the organic light-emitting device, the first electrode may be an anode, the second electrode may be a cathode, the organic layer may further include a hole transport region arranged between the first electrode and the emission layer, and an electron transport region arranged between the emission layer and the second electrode, the hole transport region may include a hole injection layer, a hole transport layer, an electron blocking layer, a buffer layer, or a combination thereof, and the electron transport region may include a hole blocking layer, an electron transport layer, an electron injection layer, or a combination thereof.
The term “organic layer” as used herein refers to a single layer and/or all of a plurality of layers that are arranged between the first electrode and the second electrode of the organic light-emitting device. The “organic layer” may include not only organic compounds, but also organometallic complexes including metals.
The FIGURE is a schematic cross-sectional view of an organic light-emitting device 10 according to one or more embodiments. Hereinafter, a structure and manufacturing method of the organic light-emitting device 10 according to one or more embodiments will be described in further detail with reference to the FIGURE, but embodiments are not limited thereto. The organic light-emitting device 10 may include a first electrode 11, an organic layer 15, and a second electrode 19, which may be sequentially layered in this stated order.
A substrate may be additionally disposed under the first electrode 11 or above the second electrode 19. The substrate may be a conventional substrate used in organic light-emitting devices, for example, a glass substrate or a transparent plastic substrate, each having excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and/or water repellency.
The first electrode 11 may be, for example, formed by depositing or sputtering a material for forming the first electrode 11 on the substrate. The first electrode 11 may be an anode. The material for forming the first electrode 11 may be selected from materials with a high work function to facilitate hole injection. The first electrode 11 may be a reflective electrode, a semi-transmissive electrode, or a transmissive electrode. The material for forming the first electrode 11 may be indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO2), or zinc oxide (ZnO). In one or more embodiments, the material for forming the first electrode 11 may be metal, such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), or magnesium-silver (Mg—Ag).
The first electrode 11 may have a single layered structure or a multilayer structure including a plurality of layers. For example, the first electrode 11 may have a three-layered structure of ITO/Ag/ITO, but embodiments are not limited thereto.
The organic layer 15 may be disposed above the first electrode 11.
The organic layer 15 may include a hole transport region; an emission layer; and an electron transport region.
The hole transport region may be arranged between the first electrode 11 and the emission layer.
The hole transport region may include a hole injection layer, a hole transport layer, an electron blocking layer, a buffer layer, or a combination thereof.
The hole transport region may include only a hole injection layer or only a hole transport layer. In one or more embodiments, the hole transport region may have a hole injection layer/hole transport layer structure, or a hole injection layer/hole transport layer/electron blocking layer structure, wherein, for each structure, respective layers are sequentially stacked in the stated order from the first electrode 11.
When the hole transport region includes a hole injection layer, the hole injection layer (HIL) may be formed on the first electrode 11 by using one or more suitable methods, for example, vacuum deposition, spin coating, casting, and/or Langmuir-Blodgett (LB) deposition.
When the hole injection layer is formed by vacuum deposition, conditions for the deposition may vary depending on a compound that is used as a material for forming the hole injection layer and a structure and thermal properties of the desired hole injection layer. For example, a deposition temperature may be about 100° C. to about 500° C., a vacuum may be about 10−8 torr to about 10−3 torr, and a deposition rate may be about 0.01 angstroms per second (Å/sec) to about 100 Å/sec, but embodiments are not limited thereto.
When the hole injection layer is formed by spin coating, conditions for the coating may vary depending on a compound that is used as a material for forming the hole injection layer and a structure and thermal properties of the desired hole injection layer. A coating speed may be about 2,000 revolutions per minute (rpm) to about 5,000 rpm, and a heat treatment temperature may be about 80° C. to about 200° C. to remove a solvent after the coating, but embodiments are not limited thereto.
Conditions for forming the hole transport layer and the electron blocking layer may be similar to or the same as the conditions for forming the hole injection layer.
The hole transport region may include, for example, at least one of 4,4′,4″-tris(3-methylphenylphenylamino)triphenylamine (m-MTDATA), 4,4′,4″-tris(N,N-diphenylamino)triphenylamine (TDATA), 4,4′,4″-tris{N-(2-naphthyl)-N-phenylamino}-triphenylamine (2-TNATA), N,N′-di(1-naphthyl)-N,N′-diphenylbenzidine (NPB), β-NPB, N,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1-biphenyl]-4,4′-diamine (TPD), spiro-TPD, spiro-NPB, methylated NPB, 4,4′-cyclohexylidene bis[N,N-bis(4-methylphenyl)benzenamine] (TAPC), 4,4′-bis[N,N′-(3-tolyl)amino]-3,3′-dimethylbiphenyl (HMTPD), 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA), polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA), poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS), polyaniline/camphor sulfonic acid (PANI/CSA), (polyaniline)/poly(4-styrenesulfonate) (PANI/PSS), a compound represented by Formula 201, or a compound represented by Formula 202, but embodiments are not limited thereto:
Ar101 and Ar102 in Formula 201 may each independently be:
xa and xb in Formula 201 may each independently be an integer from 0 to 5, or 0, 1, or 2. For example, xa may be 1, and xb may be 0, but embodiments are not limited thereto.
R101 to R108, R111 to R119, and R121 to R124 in Formulae 201 and 202 may each independently be:
R109 in Formula 201 may be:
According to one or more embodiments, the compound represented by Formula 201 may be represented by Formula 201A, but embodiments are not limited thereto:
wherein, in Formula 201A, R101, R111, R112, and R109 may each be as described herein.
For example, the compound represented by Formula 201 and the compound represented by Formula 202 may include one or more of Compounds HT1 to HT20, but embodiments are not limited thereto:
A thickness of the hole transport region may be about 100 Å to about 10,000 Å, for example, about 100 Å to about 1,000 Å. When the hole transport region includes at least one of a hole injection layer and a hole transport layer, a thickness of the hole injection layer may be about 100 Å to about 10,000 Å, for example, about 100 Å to about 1,000 Å, and a thickness of the hole transport layer may be about 50 Å to about 2,000 Å, for example, about 100 Å to about 1,500 Å. Without wishing to be bound to theory, when the thicknesses of the hole transport region, the hole injection layer, and the hole transport layer are within these ranges, satisfactory hole transporting characteristics may be obtained without a substantial increase in driving voltage.
The hole transport region may further include, in addition to the materials as described herein, a charge-generation material for improving conductive properties. The charge-generation material may be homogeneously or non-homogeneously dispersed in the hole transport region.
The charge generation material may be, for example, a p-dopant. The p-dopant may be one of a quinone derivative, a metal oxide, or a cyano group-containing compound, but is not limited thereto. For example, non-limiting examples of the p-dopant may be a quinone derivative, such as tetracyanoquinodimethane (TCNQ), 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinonedimethane (F4-TCNQ), 1,3,4,5,7,8-hexafluorotetracyanonaphthoquinodimethane (F6-TCNQ), or the like; a metal oxide, such as a tungsten oxide, a molybdenum oxide, or the like; or a cyano group-containing compound, such as one of Compounds HT-D1 or F12, but embodiments are not limited thereto:
The hole transport region may further include a buffer layer.
The buffer layer may compensate for an optical resonance distance according to a wavelength of light emitted from the emission layer, thereby improving efficiency.
An emission layer may be formed on the hole transport region by vacuum deposition, spin coating, casting, LB deposition, or the like. When the emission layer is formed by vacuum deposition or spin coating, the deposition and coating conditions may vary depending on a compound that is used, but in general, may be similar to the conditions for forming the hole injection layer.
In one or more embodiments, when the hole transport region includes an electron blocking layer, a material for forming the electron blocking layer may be selected from materials that may be used in the hole transport region as described above and host materials described herein. However, embodiments are not limited thereto. For example, when the hole transport region includes an electron blocking layer, a material for forming the electron blocking layer may be 1,3-bis(N-carbazolyl)benzene (mCP), as described herein.
The emission layer may include a host and a dopant, and the dopant may include at least one of the organometallic compounds represented by Formula 1.
The host may include, for example, at least one of 1,3,5-tri(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene (TPBi), 3-tert-butyl-9,10-di(naphth-2-yl)anthracene (TBADN), 9,10-di(naphthalene-2-yl)anthracene (ADN) (also referred to as “DNA”), 4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP), 4,4′-bis(9-carbazolyl)-2,2′-dimethyl-biphenyl (CDBP), 1,3,5-tris(carbazole-9-yl)benzene (tCP), 1,3-bis(N-carbazolyl)benzene (mCP), Compound H50, or Compound H51, but embodiments are not limited thereto:
In one or more embodiments, the host may include a compound represented by Formula 301, but embodiments are not limited thereto:
wherein, in Formula 301, Ar111 and Ar112 may each independently be:
Ar113 to Ar116 in Formula 301 may each independently be:
g, h, i, and j in Formula 301 may each independently be an integer from 0 to 4, for example, 0, 1, or 2.
but embodiments are not limited thereto.
In one or more embodiments, the host may include a compound represented by Formula 302, but embodiments are not limited thereto:
Ar122 to Ar125 in Formula 302 may each be as described in detail in connection with Ar113 in Formula 301.
Ar126 and Ar127 in Formula 302 may each independently be a C1-C10 alkyl group (for example, a methyl group, an ethyl group, a propyl group, or the like).
k and l in Formula 302 may each independently be an integer from 0 to 4. For example, k and l may each independently be 0, 1, or 2.
When the organic light-emitting device is a full-color organic light-emitting device, the emission layer may be patterned into a red emission layer, a green emission layer, and/or a blue emission layer. In one or more embodiments, due to a stacked structure including a red emission layer, a green emission layer, and/or a blue emission layer, the emission layer may emit white light, and various modifications may be made.
When the emission layer includes a host and a dopant, an amount of the dopant may be about 0.01 parts by weight to about 15 parts by weight, based on 100 parts by weight of the host, but embodiments are not limited thereto.
A thickness of the emission layer may be about 100 Å to about 1,000 Å, for example, about 200 Å to about 600 Å. Without wishing to be bound to theory, when the thickness of the emission layer is within this range, excellent light-emission characteristics may be obtained without a substantial increase in driving voltage.
An electron transport region may be disposed above the emission layer.
The electron transport region may include a hole blocking layer, an electron transport layer, an electron injection layer, or a combination thereof.
For example, the electron transport region may have a hole blocking layer/electron transport layer/electron injection layer structure, or an electron transport layer/electron injection layer structure, but embodiments are not limited thereto. The electron transport layer may have a single-layered structure or a multilayer structure including two or more different materials.
Conditions for forming the hole blocking layer, the electron transport layer, and the electron injection layer of the electron transport region may be similar to or the same as the conditions for forming the hole injection layer.
When the electron transport region includes a hole blocking layer, the hole blocking layer may include, for example, at least one of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), or bis(2-methyl-8-quinolinolato-N1,08)-(1,1′-biphenyl-4-olato)aluminum (BAlq), but embodiments are not limited thereto.
A thickness of the hole blocking layer may be about 20 Å to about 1,000 Å, for example, about 30 Å to about 300 Å. Without wishing to be bound to theory, when the thickness of the hole blocking layer is within the range as described above, excellent hole blocking characteristics may be obtained without a substantial increase in driving voltage.
The electron transport layer may further include, for example, at least one of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), tris(8-hydroxy-quinolinato)aluminum (Alq3), bis(2-methyl-8-quinolinolato-N1,08)-(1,1′-biphenyl-4-olato)aluminum (BAlq), 3-(4-biphenylyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ), or 4-(naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (NTAZ), but embodiments are not limited thereto.
In one or more embodiments, the electron transport layer may include at least one of Compounds ET1 to ET25, but embodiments are not limited thereto.
A thickness of the electron transport layer may be about 100 Å to about 1,000 Å, for example, about 150 Å to about 500 Å. Without wishing to be bound to theory, when the thickness of the electron transport layer is within the range as described above, satisfactory electron transporting characteristics may be obtained without a substantial increase in driving voltage.
The electron transport layer may include, in addition to the materials described above, a metal-containing material.
The metal-containing material may include a Li complex. The Li complex may include, for example, one or more of Compound ET-D1 (lithium quinolate (LiQ)) or Compound ET-D2, but embodiments are not limited thereto:
In addition, the electron transport region may include an electron injection layer (EIL) that facilitates the flow of electrons from the second electrode 19 thereinto.
The electron injection layer may include LiF, NaCl, CsF, Li2O, BaO, or a combination thereof.
A thickness of the electron injection layer may be about 1 Å to about 100 Å, and, for example, about 3 Å to about 90 Å. Without wishing to be bound to theory, when the thickness of the electron injection layer is within this range, satisfactory electron injection characteristics may be obtained without a substantial increase in driving voltage.
The second electrode 19 may be provided above the organic layer 15. The second electrode 19 may be a cathode. A material for forming the second electrode 19 may be a metal, an alloy, an electrically conductive compound, or a combination thereof, which has a relatively low work function. Examples of the material for forming the second electrode 19 may include lithium (Li), magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), and magnesium-silver (Mg—Ag). In one or more embodiments, to obtain a top-emission type light-emitting device, a transmissive electrode formed using ITO or IZO may be used as the second electrode 19, and various modifications may be made.
Hereinbefore, the organic light-emitting device has been described with reference to the FIGURE, but embodiments are not limited thereto.
According to one or more embodiments, there is provided a diagnostic composition including at least one of the organometallic compounds represented by Formula 1.
The organometallic compound represented by Formula 1 provides a high emission efficiency. Accordingly, the diagnostic composition including at least one of the organometallic compounds represented by Formula 1 may have a high diagnostic efficiency.
The diagnostic composition may be used in various applications including, for example, a diagnosis kit, a diagnosis reagent, a biosensor, a biomarker, or the like, but embodiments are not limited thereto.
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 non-limiting examples thereof include a methyl group, an ethyl group, a propyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an isoamyl group, a hexyl group, or the like. The term “C1-C60 alkylene group” as used herein refers to a divalent group having substantially the same structure as the C1-C60 alkyl group.
The term “C1-C60 alkoxy group” as used herein refers to a monovalent group represented by —OA101 (wherein A101 is the C1-C60 alkyl group), and non-limiting examples thereof include a methoxy group, an ethoxy group, an isopropyloxy group, or the like.
The term “C1-C60 alkylthio group” as used herein refers to a monovalent group represented by —SA101, (wherein A101, is the C1-C60 alkyl group).
The term “C2-C60 alkenyl group” as used herein has a structure including at least one carbon-carbon double bond in the middle or at the terminus of the C2-C60 alkyl group, and non-limiting examples thereof include an ethenyl group, a propenyl group, a butenyl group, or the like. 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 has a structure including at least one carbon-carbon triple bond in the middle or at the terminus of the C2-C60 alkyl group. Non-limiting examples thereof include an ethynyl group, a propynyl group, or the like. 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 non-limiting examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, or the like. 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 cyclic group having at least one heteroatom selected from N, O, P, Si, S, Se, Ge, and B as a ring-forming atom and 1 to 10 carbon atoms as ring-forming atom(s), and non-limiting examples thereof include a tetrahydrofuranyl group, a tetrahydrothiophenyl group, or the like. 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 cyclic group that has 3 to 10 carbon atoms, 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, a cycloheptenyl group, or the like. 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 cyclic group that has at least one heteroatom selected from N, O, P, Si, S, Se, Ge, and B as a ring-forming atom, 1 to 10 carbon atoms as ring-forming atom(s), and at least one double bond in its ring. Non-limiting examples of the C1-C1a heterocycloalkenyl group include a 2,3-dihydrofuranyl group, a 2,3-dihydrothiophenyl group, or the like. 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 that includes a carbocyclic aromatic ring system having 6 to 60 carbon atoms, and the term “C6-C60 arylene group” as used herein refers to a divalent group that includes a carbocyclic aromatic ring system having 6 to 60 carbon atoms. Non-limiting examples of the C6-C60 aryl group include a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, a chrysenyl group, or the like. When each of the C6-C60 aryl group and the C6-C60 arylene group includes two or more rings, the two or more rings may be fused to each other.
The term “C7-C60 alkyl aryl group” as used herein refers to a C6-C60 aryl group that is substituted with at least one C1-C60 alkyl group. The term “C7-C60 aryl alkyl group” as used herein refers to a C6-C60 alkyl group that is substituted with at least one C1-C60 aryl group.
The term “C1-C60 heteroaryl group” as used herein refers to a monovalent group having a cyclic aromatic ring system that has at least one heteroatom selected from N, O, P, Si, S, Se, Ge, and B as a ring-forming atom, and 1 to 60 carbon atoms as ring-forming atom(s). The term “C1-C60 heteroarylene group” as used herein refers to a divalent group having a carbocyclic aromatic ring system that has at least one heteroatom selected from N, O, P, Si, S, Se, Ge, and B as a ring-forming atom, and 1 to 60 carbon atoms as ring-forming atom(s). Non-limiting examples of the C1-C60 heteroaryl group include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, or the like. When each of the C1-C60 heteroaryl group and the C1-C60 heteroarylene group includes two or more rings, the two or more rings may be fused to each other.
The term “C2-C60 alkyl heteroaryl group” as used herein refers to a C1-C60 heteroaryl group that is substituted with at least one C1-C60 alkyl group. The term “C2-C60 heteroaryl alkyl group” as used herein refers to a C1-C60 alkyl group that is substituted with at least one C1-C60 heteroaryl group.
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 “C1-C60 heteroaryloxy group” as used herein refers to —OA104 (wherein A104 is the C1-C60 heteroaryl group), and the term “C1-C60 heteroarylthio group” as used herein refers to —SA105 (wherein A105 is the C1-C60 heteroaryl group).
The term “monovalent non-aromatic condensed polycyclic group” as used herein refers to a monovalent group having two or more rings condensed to each other, only carbon atoms (for example, having 8 to 60 carbon atoms) as ring-forming atoms, and no aromaticity in its molecular structure when considered as a whole. Non-limiting examples of the monovalent non-aromatic condensed polycyclic group include a fluorenyl group or the like. The term “divalent non-aromatic condensed polycyclic group” as used herein refers to a divalent group having the same structure as a monovalent non-aromatic condensed polycyclic group.
The term “monovalent non-aromatic condensed heteropolycyclic group” as used herein refers to a monovalent group having two or more rings condensed together, a heteroatom selected from N, O, P, Si, S, Se, Ge, and B, other than carbon atoms (for example, having 1 to 60 carbon atoms), as a ring-forming atom, and no aromaticity in its molecular structure when considered as a whole. Non-limiting examples of the monovalent non-aromatic condensed heteropolycyclic group include a carbazolyl group or the like. The term “divalent non-aromatic condensed heteropolycyclic group” as used herein refers to a divalent group having the same structure as a monovalent non-aromatic condensed heteropolycyclic group.
The term “C5-C30 carbocyclic group” as used herein refers to a saturated or unsaturated ring group including 5 to 30 carbon atoms only as ring-forming atoms. The C5-C30 carbocyclic group may be a monocyclic group or a polycyclic group.
The term “C1-C30 heterocyclic group” as used herein refers to a saturated or unsaturated ring group including 1 to 30 carbon atoms and at least one heteroatom selected from N, O, P, Si, S, Se, Ge, and B as a ring-forming atom. The C1-C30 heterocyclic group may be a monocyclic group or a polycyclic group.
At least one substituent of the substituted C5-C30 carbocyclic group, the substituted C1-C60 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 C1-C60 alkylthio 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 C7-C60 alkyl aryl group, the substituted C7-C60 aryl alkyl group, the substituted C6-C60 aryloxy group, the substituted C6-C60 arylthio group, the substituted C1-C60 heteroaryl group, the substituted C2-C60 alkyl heteroaryl group, the substituted C2-C60 heteroaryl alkyl group, the substituted C1-C60 heteroaryloxy group, the substituted C1-C60 heteroarylthio group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group may be:
Hereinafter, organometallic compounds and an organic light-emitting device according to exemplary embodiments are described in further detail with reference to Synthesis Example and Examples. However, the disclosure is not limited to the following Synthesis Examples and Examples. The wording “B was used instead of A” used in describing Synthesis Examples means that an amount of B used was identical to an amount of A used based on molar equivalence.
Under a nitrogen environment, 1-chloro-9,9-dimethyl-7-(4-(trifluoromethyl)phenyl)-9H-benzo[4,5]germolo[2,3-c]pyridine (1.00 gram (g), 2.30 millimoles (mmol)) and 2-(4-(tert-butyl)naphthalene-2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxoborolane (0.79 g, 2.53 mmol) were dissolved in 60 milliliters (mL) of 1,4-dioxane to form a first solution. A second solution was prepared by dissolving potassium carbonate (K2CO3) (0.73 g, 5.28 mmol) in 20 mL of deionized (DI) water. The second solution was added to the first solution to form a reaction mixture, and then a palladium catalyst tetrakis(triphenylphosphine)palladium(0) (Pd(PPh3)4) (0.13 g, 0.12 mmol) was added thereto. Afterwards, the resulting reaction mixture was stirred while refluxing at 110° C. After cooling to room temperature, a solid obtained after extraction was purified by column chromatography (eluents: ethyl acetate (EA) and n-hexane) to obtain 1.13 g (yield of 84%) of Compound 4A, which was 1-(4-(tert-butyl)naphthalene-2-yl)-9,9-dimethyl-7-(4-(trifluoromethyl)phenyl)-9H-benzo[4,5]germolo[2,3-c]pyridine. The material was identified by high resolution mass spectrometry using matrix assisted laser desorption ionization (HRMS (MALDI)) and high-performance liquid chromatography (HPLC) analysis.
HRMS (MALDI) calculated for C34H30F3GeN: m/z: 582.25; found: 583.32.
Compound 4A (1.21 g, 2.08 mmol) and iridium chloride trihydrate (0.35 g, 0.99 mmol) were mixed with 20 mL of 2-ethoxyethanol and 7 mL of DI water, followed by stirring while refluxing for 24 hours, and then the temperature was allowed to lower to room temperature. The resulting solid was separated therefrom by filtration and then washed sufficiently with water, methanol, and hexane, in the stated order, and the solid thus obtained was dried in a vacuum oven, to thereby obtain 1.20 g (yield of 87%) of Compound 4B. Compound 4B thus obtained was used in the next reaction without additional purification.
Pentane-2,4-dione (0.11 g, 1.10 mmol) and potassium carbonate (K2CO3) (0.15 g, 1.08 mmol) were added to Compound 4B (1.20 g, 0.43 mmol), and then mixed with 15 mL of 2-ethoxyethanol, followed by stirring at room temperature for 18 hours. A solid obtained after extraction was purified by column chromatography (eluents: methylene chloride (MC) and hexane) to thereby obtain 1.04 g (yield of 83%) of Compound 4. The material was identified by HRMS (MALDI) and HPLC analysis.
HRMS (MALDI) calculated for C73H65F6Ge2IrN2O2: m/z: 1453.80; found: 1455.62.
1.12 g (yield of 89%) of Compound 5 was obtained in a similar manner as in the synthesis of Compound 4 of Synthesis Example 1, except that, during the synthesis of Compound 5A, in the synthesis of Compound 4A, 1-chloro-9,9-dimethyl-7-(4-(trimethylsilyl)phenyl)-9H-benzo[4,5]germolo[2,3-c]pyridine (1.00 g, 2.28 mmol) was used instead of 1-chloro-9,9-dimethyl-7-(4-(trifluoromethyl)phenyl)-9H-benzo[4,5]germolo[2,3-c]pyridine. The material was identified by HRMS (MALDI) and HPLC analysis.
H RMS (MALDI) calculated for C77H83Ge2IrN2O2Si2: m/z: 1462.17; found: 1464.22.
1.06 g (yield of 84%) of Compound 50 was obtained in a similar manner as in the synthesis of Compound 4 of Synthesis Example 1, except that, during the synthesis of Compound 50A, in the synthesis of Compound 4A, 1-chloro-9,9-dimethyl-7-(trimethylsilyl)-9H-benzo[4,5]germolo[2,3-c]pyridine (1.00 g, 2.76 mmol) was used instead of 1-chloro-9,9-dimethyl-7-(4-(trifluoromethyl)phenyl)-9H-benzo[4,5]germolo[2,3-c]pyridine. The material was identified by HRMS (MALDI) and HPLC analysis.
HRMS (MALDI) calculated for C65H75Ge2IrN2O2Si2: m/z: 1309.97; found: 1311.95.
1.08 g (yield of 86%) of Compound 59 was obtained in a similar manner as in the synthesis of Compound 4 of Synthesis Example 1, except that, during the synthesis of Compound 59A, in the synthesis of Compound 4A, 1-chloro-8,9,9-trimethyl-7-(trimethylsilyl)-9H-benzo[4,5]germolo[2,3-c]pyridine (1.00 g, 2.66 mmol) was used instead of 1-chloro-9,9-dimethyl-7-(4-(trifluoromethyl)phenyl)-9H-benzo[4,5]germolo[2,3-c]pyridine. The material was identified by HRMS (MALDI) and HPLC analysis.
HRMS (MALDI) calculated for C67H79Ge2IrN2O2Si2: m/z: 1338.03; found: 1340.21.
1.25 g (yield of 88%) of Compound 1 was obtained in a similar manner as in the synthesis of Compound 4 of Synthesis Example 1, except that, during the synthesis of Compound 1A, in the synthesis of Compound 4A, 1-chloro-9,9-dimethyl-7-(4-(trifluoromethyl)phenyl)-9H-benzo[4,5]silolo[2,3-c]pyridine (1.00 g, 2.57 mmol) was used instead of 1-chloro-9,9-dimethyl-7-(4-(trifluoromethyl)phenyl)-9H-benzo[4,5]germolo[2,3-c]pyridine. The material was identified by HRMS (MALDI) and HPLC analysis.
HRMS (MALDI) calcd for C73H65F6IrN2O2Si2: m/z: 1364.71; found: 1365.63.
1.23 g (yield of 89%) of Compound 7 was obtained in a similar manner as in the synthesis of Compound 4 of Synthesis Example 1, except that, during the synthesis of Compound 7A, in the synthesis of Compound 4A, 1-chloro-9,9-dimethyl-7-(4-(trifluoromethyl)phenyl)-9H-indeno[2,1-c]pyridine (1.00 g, 2.68 mmol) was used instead of 1-chloro-9,9-dimethyl-7-(4-(trifluoromethyl)phenyl)-9H-benzo[4,5]germolo[2,3-c]pyridine. The material was identified by HRMS (MALDI) and HPLC analysis.
HRMS (MALDI) calculated for C75H65F6IrN2O2: m/z: 1332.56; found: 1333.48.
As an anode, an ITO-patterned glass substrate was cut to a size of 50 millimeters (mm)×50 mm×0.5 mm, sonicated with isopropyl alcohol and DI water, each for 5 minutes, and then cleaned by irradiation of ultraviolet rays and exposure of ozone thereto for 30 minutes. The resultant glass substrate was loaded onto a vacuum deposition apparatus.
Compounds HT3 and F12-P-dopant were co-deposited by vacuum on the anode at a weight ratio of 98:2 to form a hole injection layer having a thickness of 100 Å, and Compound HT3 was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 1,600 Å.
Next, Compound RH3 (host) and Compound 4 (dopant) were co-deposited by vacuum on the hole transport layer at a weight ratio of 97:3 to form an emission layer having a thickness of 400 Å.
Afterwards, Compound ETL and Liq-N-Dopant were co-deposited by vacuum on the emission layer at a volume ratio of 50:50 to form an electron transport layer having a thickness of 350 Å, Liq-N-Dopant was vacuum-deposited on the electron transport layer to form an electron injection layer having a thickness of 10 Å, and Al was vacuum-deposited on the electron injection layer to form a cathode having a thickness of 1,000 Å, thereby completing the manufacture of an organic light-emitting device.
The organic light-emitting devices were manufactured in a similar manner as in Example 1, except that, in forming the emission layer, for use as a dopant in the emission layer, corresponding compounds shown in Table 2 were used instead of Compound 4.
A driving voltage (Volts, V), roll-off ratio (%), maximum emission wavelength (λmax, nm), FWHM (nm), and maximum external quantum efficiency (Max EQE, %) of each of the organic light-emitting devices manufactured in Examples 1 to 6 and Comparative Examples 1 to 3 were evaluated. Results thereof are shown in Table 2. A current voltmeter (Keithley 2400) and a luminance meter (Minolta Cs-1000A) were used as evaluation apparatuses. The roll-off ratio was calculated according to Equation 2.
Roll-off ratio={1−(efficiency (at 3,500 cd/m2)/maximum emission efficiency)}×100% Equation 2
From Table 2, it was found that the organic light-emitting devices of Examples 1 to 6 had low driving voltage, low roll-off ratio, narrow FWHM, and increased maximum external quantum efficiency characteristics.
From Table 2, it was found that the organic light-emitting devices of Examples 1 to 6 had lower driving voltage, lower roll-off ratio, and higher maximum external quantum efficiency than the organic light-emitting devices of Comparative Examples 1 to 3.
The organometallic compounds represented by Formula 1 have excellent electric characteristics, and thus, an electronic device, for example, an organic light-emitting device, including at least one of the organometallic compounds represented by Formula 1 may have low driving voltage, low roll-off ratio, and high maximum external quantum efficiency characteristics. Therefore, a high-quality organic light-emitting device may be implemented by using the organometallic compound represented by Formula 1.
It should be understood that exemplary embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each exemplary embodiment should typically be considered as available for other similar features or aspects in other exemplary embodiments. While one or more exemplary embodiments have been described with reference to the FIGURE, 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 |
|---|---|---|---|
| 10-2022-0165096 | Nov 2022 | KR | national |
