Patent Application
20230329084
This application is based on and claims priority to Korean Patent Application No. 10-2022-0044638, filed on Apr. 11, 2022, in the Korean Intellectual Property Office, and all the benefits accruing therefrom under 35 U.S.C. § 119, the content of which is incorporated by reference herein in its entirety.
The present disclosure 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 that 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 includes 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 move toward the emission layer through the hole transport region, and electrons provided from the cathode move toward the emission layer through the electron transport region. The holes and the electrons recombine in the emission layer to produce excitons. These excitons transition from an excited state to a ground state, thereby generating light.
Provided are 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 which follows and, in part, will be apparent from the detailed description, or may be learned by practice of the presented exemplary embodiments.
According to an aspect, provided is an organometallic compound represented by Formula 1:
M1(L1)n1(L2)n2. Formula 1
wherein,
wherein, in Formulae 1A and 1B,
According to another aspect, 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, wherein the organic layer includes an emission layer, and wherein the organic layer further includes at least one of the organometallic compound.
The organometallic compound may be included in the emission layer of the organic layer, and the organometallic compound included in the emission layer may act as a dopant.
According to still another aspect, provided is 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 FIGURE, which 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. 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. 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, a work function or a highest occupied molecular orbital (HOMO) energy level is expressed as an absolute value from a vacuum level. In addition, 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 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.
An aspect provides an organometallic compound represented by Formula 1:
M1(L1)n1(L2)n2 Formula 1
wherein, in Formula 1, M1 is a transition metal.
In an embodiment, 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 (Ir), platinum (Pt), palladium (Pd), gold (Au), osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), thulium (Tm), or rhodium (Rh).
For example, M1 may be Ir, Os, Pt, Pd, or Au.
In one or more embodiments, M1 may be Ir.
n1 and n2 in Formula 1 are each independently 1 or 2.
In one or more embodiments, the 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:
wherein, 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.
Ring CY1 and ring CY2 in Formula 1A are each independently a C5-C30 carbocyclic group or a C1-C30 heterocyclic group.
In one or more embodiments, ring CY1 and ring CY2 may each independently be i) a first ring, ii) a second ring, iii) a condensed ring in which at least two first rings are condensed together, iv) a condensed ring in which at least two second rings are condensed together, or v) a condensed ring in which at least one first ring is condensed with at least one second ring,
In one or more embodiments, ring CY1 and ring CY2 may each independently be a cyclopentane group, a cyclohexane group, a cycloheptane group, a cyclopentene group, a cyclohexene group, a cycloheptene group, a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a cyclopentadiene group, a 1,2,3,4-tetrahydronaphthalene group, a thiophene group, a furan group, an indole group, a benzoborole group, a benzophosphole group, an indene group, a benzosilole group, a benzogermole group, a benzothiophene group, a benzoselenophene group, a benzofuran group, a carbazole group, a dibenzoborole group, a dibenzophosphole group, a fluorene group, a dibenzosilole group, a dibenzogermole group, a dibenzothiophene group, a dibenzoselenophene group, a dibenzofuran group, a dibenzothiophene 5-oxide group, a 9H-fluoren-9-one group, a dibenzothiophene 5,5-dioxide group, an azaindole group, an azabenzoborole group, an azabenzophosphole group, an azaindene group, an azabenzosilole group, an azabenzogermole group, an azabenzothiophene group, an azabenzoselenophene group, an azabenzofuran group, an azacarbazole group, an azadibenzoborole group, an azadibenzophosphole group, an azafluorene group, an azadibenzosilole group, an azadibenzogermole group, an azadibenzothiophene group, an azadibenzoselenophene group, an azadibenzofuran group, an azadibenzothiophene 5-oxide group, an aza-9H-fluoren-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 pyrrole 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, a benzothiadiazole group, a 5,6,7,8-tetrahydroisoquinoline group, or a 5,6,7,8-tetrahydroquinoline group.
In one or more embodiments, ring CY1 and ring CY2 may each independently 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.
In one or more embodiments, ring CY1 may be a pyridine group, a pyrimidine group, a pyrazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, or a quinazoline group.
In one or more embodiments, ring CY2 may be a benzene group or a naphthalene group.
In one or more embodiments, ring CY1 may be represented by one of Formulae 1-1 to 1-32:
wherein, in Formulae 1-1 to 1-32,
In one or more embodiments, ring CY2 may be represented by one of Formulae 2-1 to 2-32:
wherein, in Formulae 2-1 to 2-32,
Z1 and Z2 in Formula 1A may each independently be —Si(Q1)(Q2)(Q3) or —Ge(Q1)(Q2)(Q3).
In one or more embodiments, Z1 and Z2 may each not be —SiH3.
In one or more embodiments, Q1 to Q3 in Z1 and Z2 may each independently be:
For example, Q1 to Q3 in Z1 may each be —CH3, —CD3, —CD2H, or —CDH2.
For example, Q1 to Q3 in Z2 may each be —CH3, —CD3, —CD2H, or —CDH2.
a1 and a2 in Formula 1A are each independently an integer of 0 to 10.
A sum of a1 and a2 in Formula 1A is 1 or greater.
In one or more embodiments, the sum of a1 and a2 may be 1.
For example, i) a1 may be 1 and a2 may be 0, or ii) a1 may be 0 and a2 may be 1.
R1 and R2 in Formula 1A are each independently 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 C2-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 and R2 may each independently be:
In one or more embodiments, R1 and R2 may each independently be:
wherein, in Formulae 9-1 to 9-39, 9-44 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 and b2 in Formula 1A are each independently an integer of i to 10.
L2 in Formula 1 is a ligand represented by Formula 1B:
wherein, in Formula 1B, X3 is C or N, and X4 is C or N.
A bond between M1 and X3 in Formula 1A may be a covalent bond or a coordinate bond.
A bond between M1 and X4 in Formula 1A may be a covalent bond or a coordinate bond.
In one or more embodiments, X3 may be N, X4 may be C, a bond between X3 and M1 may be a coordinate bond, and a bond between X4 and M1 may be a covalent bond.
Ring CY4 in Formula 1B is a C5-C30 carbocyclic group or a C1-C30 heterocyclic group.
In one or more embodiments, ring CY4 may be i) a first ring, ii) a second ring, iii) a condensed ring in which at least two first rings are condensed together, iv) a condensed ring in which at least two second rings are condensed together, or v) a condensed ring in which at least one first ring is condensed with at least one second ring,
In one or more embodiments, ring CY4 may be a cyclopentane group, a cyclohexane group, a cycloheptane group, a cyclopentene group, a cyclohexene group, a cycloheptene group, a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a cyclopentadiene group, a 1,2,3,4-tetrahydronaphthalene group, a thiophene group, a furan group, an indole group, a benzoborole group, a benzophosphole group, an indene group, a benzosilole group, a benzogermole group, a benzothiophene group, a benzoselenophene group, a benzofuran group, a carbazole group, a dibenzoborole group, a dibenzophosphole group, a fluorene group, a dibenzosilole group, a dibenzogermole group, a dibenzothiophene group, a dibenzoselenophene group, a dibenzofuran group, a dibenzothiophene 5-oxide group, a 9H-fluoren-9-one group, a dibenzothiophene 5,5-dioxide group, an azaindole group, an azabenzoborole group, an azabenzophosphole group, an azaindene group, an azabenzosilole group, an azabenzogermole group, an azabenzothiophene group, an azabenzoselenophene group, an azabenzofuran group, an azacarbazole group, an azadibenzoborole group, an azadibenzophosphole group, an azafluorene group, an azadibenzosilole group, an azadibenzogermole group, an azadibenzothiophene group, an azadibenzoselenophene group, an azadibenzofuran group, an azadibenzothiophene 5-oxide group, an aza-9H-fluoren-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 pyrrole 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, a benzothiadiazole group, a 5,6,7,8-tetrahydroisoquinoline group, or a 5,6,7,8-tetrahydroquinoline group.
In one or more embodiments, ring CY4 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 CY4 may be a benzene group or a naphthalene group.
In one or more embodiments, ring CY4 may be represented by one of Formulae 4-1 to 4-16:
wherein, in Formulae 4-1 to 4-16,
Y1 in Formula 1B is O, S, Se, C(R5)(R6), or N(R7).
R4 to R7, R31, and R32 in Formula 1B are each independently 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 C2-C1a 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, R4 to R7, R31, and R32 may each independently be:
In one or more embodiments, R4 to R7, R31, and R32 may each independently be:
wherein, in Formulae 9-1 to 9-39, 9-44 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.
b4 in Formula 1B is an integer of 1 to 10.
b31 in Formula 1B is 1 or 2.
b32 in Formula 1B is an integer of 1 to 4.
R5 and R6 in Formula 1B are optionally bonded together to form a substituted or unsubstituted C5-C30 carbocyclic group or a substituted or unsubstituted C1-C30 heterocyclic group.
In one or more embodiments, R5 and R6 may optionally be bonded together via a single bond, a double bond, or a first linking group to form a C5-C30 carbocyclic group unsubstituted or substituted with at least one R10a, or a C1-C30 heterocyclic group unsubstituted or substituted with at least one R10a (for example, a fluorene group, an xanthene group, or an acridine group, each unsubstituted or substituted with at least one R10a).
In one or more embodiments, examples of the “C5-C30 carbocyclic group unsubstituted or substituted with at least one R10a or C1-C30 heterocyclic group unsubstituted or substituted with at least one R10a” may include a benzene group, a naphthalene group, a cyclopentane group, a cyclopentadiene group, a cyclohexane group, a cycloheptane group, a bicyclo[2.2.1]heptane group, a furan group, a thiophene group, a pyrrole group, a silole group, an indene group, a benzofuran group, a benzothiophene group, an indole group, or a benzosilole group, each unsubstituted or substituted with at least one R10a. R10a may be the same as described herein in connection with R1. The C5-C30 carbocyclic group and the C1-C30 heterocyclic group may each be the same as described herein.
The first linking group may be selected from *—N(R8)—*′, *—B(R8)—*′, *—P(R8)—*′, *—C(R8)(R9)—*′, *—Si(R8)(R9)—*′, *—Ge(R8)(R9)—*′, *—S—*′, *—Se—*′, *—O—*′, *—C(═O)—*′, *—S(═O)—*′, *—S(═O)2—*′, *—C(R8)═*′, *═C(R8)—*′, *—C(R8)═C(R8)—*′, *—C(═S)—*′, and *—C═C—*′, R8 and R9 may each be the same as described herein in connection with to R7, and * and *′ each indicate a binding site to a neighboring atom.
In one or more embodiments, Q1 to Q9, Q11 to Q19, Q21 to Q29, and Q31 to Q39 may each independently be:
In one or more embodiments, L2 may be represented by one of Formulae 1B-1 to 1B-16:
wherein, in Formulae 1B-1 to 1B-16,
In one or more embodiments, the organometallic compound may be represented by one of Formulae 5-1 to 5-8:
wherein, in Formulae 5-1 to 5-8,
In one or more embodiments, the organometallic compound may be one of Compounds 1 to 82:
In one or more embodiments, the organometallic compound may be electrically neutral.
The organometallic compound represented by Formula 1 includes a ligand represented by Formula 1A and a ligand represented by Formula 1B. The ligand represented by Formula 1A includes at least one —Si(Q1)(Q2)(Q3) or —Ge(Q1)(Q2)(Q3) as a substituent, and the ligand represented by Formula 1B has a structure in which three rings are condensed. Without wishing to be bound to theory, due to this structure, an electronic device, for example, an organic light-emitting device, including the organometallic compound represented by Formula 1 may exhibit low driving voltage, high efficiency, and long lifespan.
The highest occupied molecular orbital (HOMO) energy level, lowest unoccupied molecular orbital (LUMO) energy level, the lowest excitation triplet (T1) energy level, and the lowest excitation singlet (S1) energy level of selected compounds of the organometallic compound 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 have such electric characteristics that are suitable for use as a dopant for 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 of an emission spectrum or electroluminescence (EL) spectrum of the organometallic compound may be in a range of about 490 nanometers (nm) to about 550 nm.
Synthesis methods of the organometallic compound represented by Formula 1 may be recognizable by one of ordinary skill in the art by referring to Synthesis Examples provided below.
Accordingly, the organometallic compound represented by Formula 1 may be suitable for use as a dopant in an organic layer, for example, an emission layer, of an organic light-emitting device. Thus, another aspect provides 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 organometallic compound represented by Formula 1.
Since the organic light-emitting device includes the organic layer including the organometallic compound represented by Formula 1 as described herein, excellent characteristics in terms of driving voltage, current efficiency, external quantum efficiency, roll-off ratio, and lifespan, and relatively narrow FWHM of the emission peak of the EL spectrum may be exhibited.
The organometallic compound represented by Formula 1 may be used or located between a pair of electrodes of the organic light-emitting device. For example, the organometallic compound represented by Formula 1 may be included in the emission layer. In this regard, the organometallic compound may act as a dopant, and the emission layer may further include a host (that is, an amount of the organometallic compound represented by Formula 1 is smaller than an amount of the host in the emission layer).
In one or more embodiments, the emission layer may emit a green light. For example, the emission layer may emit a green light having a maximum emission wavelength in a range of about 490 nm to about 550 nm.
The expression “(an organic layer) includes at least one organometallic compound represented by Formula 1” as used herein may include a case in which “(an organic layer) includes identical organometallic compounds represented by Formula 1” and a case in which “(an organic layer) includes two or more different organometallic compounds represented by Formula 1”.
For example, the organic layer may include, as the organometallic compound, only Compound 1. In this regard, Compound 1 may be included in the emission layer of the organic light-emitting device. In one or more embodiments, the organic layer may include, as the organometallic compound, Compound 1 and Compound 2. In this regard, Compound 1 and Compound 2 may be present in an identical 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. Alternatively, 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, and 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, wherein 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 a plurality of layers arranged between the first electrode and the second electrode of the organic light-emitting device. The “organic layer” may include, in addition to an organic compound, an organometallic complex including metal.
The FIGURE is a schematic cross-sectional view of an organic light-emitting device 10 according to one or more embodiments. Hereinafter, the structure and manufacturing method of the organic light-emitting device 10 according to one or more embodiments will be described with reference to the FIGURE. The organic light-emitting device 10 includes a first electrode 11, an organic layer 15, and a second electrode 19, which are sequentially stacked.
A substrate may be additionally arranged under the first electrode 11 or above the second electrode 19. For use as the substrate, any suitable substrate that is used in organic light-emitting devices available in the art may be used, and the substrate may be a glass substrate or a transparent plastic substrate, each having excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and/or water resistance.
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 a metal, such as magnesium (Mg), aluminum (Al), silver (Ag), 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 multi-layered 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 is arranged on 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 or located 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 either a hole injection layer or 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 this stated order from the first electrode 11.
When the hole transport region includes a hole injection layer, the hole injection layer may be formed on the first electrode 11 by using one or more suitable methods, such as vacuum deposition, spin coating, casting, and Langmuir-Blodgett (LB) deposition.
When the hole injection layer is formed by vacuum deposition, the deposition conditions may vary according to a material that is used to form the hole injection layer, and the structure and thermal characteristics of the hole injection layer. For example, the deposition conditions may include a deposition temperature in a range of about 100° C. to about 500° C., a vacuum pressure in a range of about 10−8 torr to about 10−3 torr, and a deposition rate in a range of 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, the coating conditions may vary according to a material that is used to form the hole injection layer, and the structure and thermal characteristics of the hole injection layer. For example, the coating conditions may include a coating speed in a range of about 2,000 revolutions per minute (rpm) to about 5,000 rpm and a heat treatment temperature for removing a solvent after coating in a range of about 80° C. to about 200° C., but embodiments are not limited thereto.
Conditions for forming the hole transport layer and the electron blocking layer may be 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), p-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:
wherein, in Formula 201, Ar101 and Ar102 may each independently be:
R109 in Formula 201 may be:
In 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 in a range of about 100 angstroms (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 in a range of 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 in a range of about 50 Å to about 2,000 Å, for example, about 100 Å to about 1,500 Å. When the thicknesses of the hole transport region, the hole injection layer, and the hole transport layer are within the ranges described above, 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 above, 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, and a cyano group-containing compound, but embodiments are not limited thereto. For example, non-limiting examples of the p-dopant include: a quinone derivative, such as tetracyanoquinodimethane (TCNQ), 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinonedimethane (F4-TCNQ), or F6-TCNNQ; a metal oxide, such as a tungsten oxide or a molybdenum oxide; and a cyano group-containing compound, such as Compound HT-D1 or Compound 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 to increase efficiency.
The emission layer may be formed on the hole transport region by using one or more suitable methods, such as vacuum deposition, spin coating, casting, and/or LB deposition. When the emission layer is formed by vacuum deposition or spin coating, the deposition or coating conditions may be similar to those applied in forming the hole injection layer, though the deposition or coating conditions may vary according to a material that is used to form the emission layer.
When the hole transport region includes an electron blocking layer, a material for forming the electron blocking layer may be selected from the materials for forming a hole transport region and host materials described herein, but embodiments are not limited thereto. For example, when the hole transport region includes an electron blocking layer, the material for forming the electron blocking layer may be mCP, which is further described herein.
The emission layer may include a host and a dopant, and the dopant may include the organometallic compound represented by Formula 1.
The host may include at least one of 1,3,5-tri(1-phenyl-1H-benzo[d]imidazol-2-yl)phenyl (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:
In one or more embodiments, the host may include a compound represented by Formula 301:
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, and may be, for example, 0, 1, or 2.
Ar113 to Ar116 in Formula 301 may each independently be:
In one or more embodiments, the host may include a compound represented by Formula 302:
wherein, in Formula 302, Ar122 to Ar125 may each be as described herein 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, or a propyl group).
k and I in Formula 302 may each independently be an integer from 0 to 4. For example, k and I may each be 0, 1, or 2.
When the organic light-emitting device 10 is a full-color organic light-emitting device, the emission layer may be patterned into a red emission layer, a green emission layer, and 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 are possible.
When the emission layer includes a host and a dopant, an amount of the dopant may be in a range of 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 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 the range described above, excellent light-emission characteristics may be obtained without a substantial increase in driving voltage.
Next, the electron transport region may be arranged on 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 multi-layered structure including two or more different materials.
Conditions for forming the hole blocking layer, the electron transport layer, and the electron injection layer which constitute 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,O8)-(1,1′-biphenyl-4-olato)aluminum (BAlq), but embodiments are not limited thereto:
A thickness of the hole blocking layer may be in a range of about 20 Å to about 1,000 Å, for example, about 30 Å to about 300 Å. When the thickness of the hole blocking layer is within the range described above, excellent hole blocking characteristics may be obtained without a substantial increase in driving voltage.
The electron transport layer may further include at least one of BCP, Bphen, tris(8-hydroxy-quinolinato) aluminum (Alq3), BAlq, 3-(4-biphenylyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ), and 4-(naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (NTAZ):
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 in a 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, satisfactory electron transporting characteristics may be obtained without a substantial increase in driving voltage.
The electron transport layer may further include, in addition to the materials as described above, a metal-containing material.
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 may include an electron injection layer that facilitates electron injection from the second electrode 19.
The electron injection layer may include LiF, NaCl, CsF, Li2O, BaO, or a combination thereof.
A thickness of the electron injection layer may be in a range of about 1 Å to about 100 Å, for example, about 3 Å to about 90 Å. When the thickness of the electron injection layer is within the range described above, satisfactory electron injection characteristics may be obtained without a substantial increase in driving voltage.
The second electrode 19 may be arranged on 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. For example, the material for forming the second electrode 19 may be lithium (Li), magnesium (Mg), silver (Ag), aluminum (AI), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), or magnesium-silver (Mg—Ag). In one or more embodiments, to manufacture a top-emission type light-emitting device, a transmissive electrode formed using ITO or IZO may be used as the second electrode 19.
Hereinbefore, the organic light-emitting device 10 has been described with reference to the FIGURE, but embodiments of are not limited thereto.
Another aspect provides a diagnostic composition including at least one organometallic compound represented by Formula 1.
Since the organometallic compound represented by Formula 1 provides a high luminescence efficiency, the diagnostic composition including the organometallic compound represented by Formula 1 may have a high diagnostic efficiency.
The diagnostic composition may be used in various applications including a diagnosis kit, a diagnosis reagent, a biosensor, and/or a biomarker.
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, 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” 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, and an isopropyloxy 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 non-limiting examples thereof include an ethenyl group, a propenyl group, and a butenyl group. The term “C2-C60 alkenylene group” as used herein refers to a divalent group having 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 non-limiting examples thereof include an ethynyl group and a propynyl group. The term “C2-C60 alkynylene group” as used herein refers to a divalent group having 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, 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 monocyclic group including at least one heteroatom selected from N, O, P, Si, Ge, Se, and S 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 includes 3 to 10 carbon atoms and at least one carbon-carbon double bond in the ring thereof and has 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 selected from N, O, P, Si, Ge, Se, and S as a ring-forming atom, 1 to 10 carbon atoms, and at least one carbon-carbon double bond in the ring thereof. Non-limiting examples of the C1-C10 heterocycloalkenyl group include 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 that includes 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 that includes a carbocyclic aromatic system having 6 to 60 carbon atoms. Non-limiting examples of the C6-C60 aryl group include a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, and a chrysenyl group. When the C6-C60 aryl group and the C6-C60 arylene group each include two or more rings, the rings may be fused to each other.
The term “C7-C60 alkyl aryl group” as used herein refers to a C6-C60 aryl group substituted with at least one C1-C60 alkyl group. The term “C7-C60 aryl alkyl group” as used herein refers to a C1-C60 alkyl group substituted with at least one C6-C60 aryl group.
The term “C1-C60 heteroaryl group” as used herein refers to a monovalent group having a carbocyclic aromatic system that has at least one heteroatom selected from N, O, P, Si, Ge, Se, and S 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 selected from N, O, P, Si, Se, Ge, and S as a ring-forming atom, and 1 to 60 carbon atoms. Non-limiting examples of the C1-C60 heteroaryl group include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, and an isoquinolinyl group. When the 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 “C2-C60 alkyl heteroaryl group” as used herein refers to a C1-C60 heteroaryl group 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 substituted with at least one C1-C60 heteroaryl group.
The term “C6-C60 aryloxy group” as used herein refers to —OA102 (wherein A102 is the C6-C60 aryl group), and the term “C6-C60 arylthio group” as used herein refers to —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 (for example, having 8 to 60 carbon atoms) having two or more rings condensed to each other, only carbon atoms as ring-forming atoms, and no aromaticity in its entire molecular structure. Non-limiting 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.
The term “monovalent non-aromatic condensed heteropolycyclic group” as used herein refers to a monovalent group (for example, having 2 to 60 carbon atoms) having two or more rings condensed with each other, a heteroatom selected from N, O, P, Si, Ge, Se, and S, other than carbon atoms, as a ring-forming atom, and no aromaticity in its entire molecular structure. Non-limiting 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.
The term “C5-C30 carbocyclic group” as used herein refers to a saturated or unsaturated cyclic 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 cyclic group including 1 to 30 carbon atoms and at least one heteroatom selected from N, O, P, Si, Ge, Se, and S as ring-forming atoms. 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-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 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 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, a compound and an organic light-emitting device according to one or more embodiments will be described in further detail with reference to Synthesis Examples and Examples. However, embodiments are 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.
Synthesis of Compound 1A(1)
2-phenyl-5-(trimethylgermyl)pyridine (6.94 grams (g), 25.52 millimoles (mmol)) and iridium chloride hydrate (4.0 g, 11.34 mmol) were mixed with 120 milliliters (mL) of ethoxyethanol and 40 mL of deionized (DI) water, and stirred while heating under reflux for 24 hours. Then, the temperature was allowed to lower to room temperature. The solid produced therefrom was separated by filtration, washed sufficiently with DI water, methanol, and hexane, in this stated order, and the product was then dried in a vacuum oven to obtain 8.5 g (yield of 87%) of Compound 1A(1).
Compound 1A(1) (2.0 g, 1.3 mmol) and 60 mL of methylene chloride were mixed, and silver trifluoromethanesulfonate (AgOTf) (0.7 g, 2.7 mmol) was added thereto after being mixed with 20 mL of methanol. Then, the resultant reaction mixture was stirred for 18 hours at room temperature while light was blocked with aluminum foil, and filtered through Celite to remove a solid produced therein. The solvent was removed from the filtrate under a reduced pressure to obtain a solid (Compound 1A) which was used in the next reaction without an additional purification process.
In a nitrogen environment, phenylboronic acid (0.99 g, 8.1 mmol) and 3-chlorobenzofuro[3,2-c]pyridine (1.5 g, 7.4 mmol) were dissolved in 150 mL of 1,4-dioxane.
Then, potassium carbonate (K2CO3) (2.3 g, 22.1 mmol) was dissolved in 50 mL of DI water and added to the reaction mixture, and a palladium catalyst (tetrakis(triphenylphosphine)palladium(0), Pd(PPh3)4) (0.43 g, 0.37 mmol) was added thereto. Then, the resultant reaction mixture was stirred and heated under reflux at 100° C. After an extraction process was performed thereon, the solid thus obtained was subjected to column chromatography (eluent: ethyl acetate (EA) and n-hexane) to obtain 1.5 g (yield of 85%) of Compound 1B. The obtained compound was identified by high resolution mass spectrometry using matrix assisted laser desorption ionization (HRMS (MALDI)) and high-performance liquid chromatography (HPLC) analysis.
HRMS (MALDI) calcd for C17H11NO: m/z: 245.28 grams per mole (g/mol), found: 245.99 g/mol.
Compound 1A (1.5 g, 1.6 mmol) and Compound 1B (0.43 g, 1.74 mmol) were mixed with 10 mL of 2-ethoxyethanol and 10 mL of N,N-dimethylformamide, and stirred and heated under reflux for 24 hours. Then, the temperature was lowered. The solvents were removed under a reduced pressure, and the solid thus obtained was subjected to column chromatography (eluent: methylene chloride (MC) and hexane) to obtain 0.75 g (yield of 48%) of Compound 1. The obtained compound was identified by HRMS (MALDI) and HPLC analysis.
HRMS (MALDI) calcd for C45H42Ge2IrN3O: m/z: 978.33 g/mol, found: 980.11 g/mol.
Compound 3B was synthesized in a similar manner as was used to synthesize Compound 1B, except that 3-chloro-5,5-dimethyl-5H-indeno[1,2-c]pyridine (1.5 g, 6.53 mmol) was used instead of 3-chlorobenzofuro[3,2-c]pyridine.
0.68 g (yield of 43%) of Compound 3 was obtained in a similar manner as was used to synthesize Compound 1, except that Compound 3B was used instead of Compound 1B. The obtained compound was identified by HRMS (MALDI) and HPLC analysis.
HRMS (MALDI) calcd for C48H48Ge2IrN3: m/z: 1004.41 g/mol, found: 1006.33 g/mol.
Compound 21B was synthesized in a similar manner as was used to synthesize Compound 11B, except that 4,4,5,5-tetramethyl-2-(6-methyl-[1,1′-biphenyl]-3-yl)-1,3,2-dioxoborolane (2.4 g, 8.10 mmol) was used instead of phenylboronic acid.
0.82 g (yield of 48%) of Compound 21 was obtained in a similar manner as was used to synthesize Compound 1, except that Compound 21B was used instead of Compound 1B. The obtained compound was identified by HRMS (MALDI) and HPLC analysis.
HRMS (MALDI) calcd for C52H48Ge2IrN3O: m/z: 1068.45 g/mol, found: 1070.39 g/mol.
0.92 g (yield of 54%) of Compound 22 was obtained in a similar manner as was used to synthesize Compound 1, except that 2-phenyl-5-(trimethylsilyl)pyridine was used instead of 2-phenyl-5-(trimethylgermyl)pyridine. The obtained compound was identified by HRMS (MALDI) and HPLC analysis.
HRMS (MALDI) calcd for C52H48IrN3OSi2: m/z: 979.36 g/mol, found: 979.98 g/mol.
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 exposure to ultraviolet rays and ozone for 30 minutes. The resultant ITO-patterned glass substrate was loaded onto a vacuum deposition apparatus.
Compound 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 1,650 Å.
Next, Compound GH3 (host) and Compound 1 (dopant) were co-deposited on the hole transport layer at a weight ratio of 92:8 to form an emission layer having a thickness of 400 Å.
Then, Compound ET3 and Liq-N-Dopant were co-deposited 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.
Organic light-emitting devices were manufactured in a similar manner as was used in Example 1, except that Compounds shown in Table 2 were each used instead of Compound 1 as a dopant in forming an emission layer.
For each of the organic light-emitting devices manufactured in Examples 1 to 4 and Comparative Examples 1 to 4, the maximum value of external quantum efficiency (Max EQE, %), driving voltage (Volts, V), and maximum emission wavelength (λmax, nm) of an emission spectrum were evaluated, and results thereof are shown in Table 2. As evaluation apparatuses, a current-voltage meter (Keithley 2400) and a luminance meter (Minolta Cs-1000A) were used.
Referring to Table 2, it was confirmed that the organic light-emitting devices of Examples 1 to 4 had lower driving voltage and improved external quantum efficiency, as compared with the organic light-emitting devices of Comparative Examples 1 to 4.
The organometallic compound has excellent electrical characteristics and stability. Accordingly, an electronic device, for example, an organic light-emitting device, including the organometallic compound may have a low driving voltage, a high efficiency, and long lifespan characteristics. Accordingly, by using the organometallic compound, a high-quality organic light-emitting device may be implemented.
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 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 |
|---|---|---|---|
| 10-2022-0044638 | Apr 2022 | KR | national |
