Patent Application
20230104013
This application is based on and claims priority to Korean Patent Application No. 10-2021-0096715, filed on Jul. 22, 2021, in the Korean Intellectual Property Office, and all 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 organometallic compounds and organic light-emitting devices including the same.
Organic light-emitting devices (OLEDs) are self-emissive devices that produce full-color images, and also have wide viewing angles, high contrast ratios, short response times, and excellent characteristics in terms of luminance, driving voltage, and response speed, compared to devices in the art.
In an example, an organic light-emitting device includes an anode, a cathode, and an organic layer arranged between the anode and the cathode, wherein the organic layer 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 recombine in the emission layer to produce excitons. These excitons transition from an excited state to a ground state, thereby generating light.
Provided are organometallic compounds and organic light-emitting devices including the same.
Additional aspects will be set forth in part in the description, which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments of the disclosure.
According to an aspect, provided is an organometallic compound represented by Formula 1:
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 organometallic compound.
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 embodiments of the disclosure will be more apparent from the following description taken in conjunction with the drawing.
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 detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout the specification. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described below, by referring to the FIGURES, to explain aspects. As used herein, the term “and/or” includes any and all combinations of one or more of the same 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.
According to an aspect, an organometallic compound is represented by Formula 1:
In Formula 1, M1 is a transition metal.
In Formula 1, M1 may be a Period 1 transition metal of the Periodic Table of Elements, a Period 2 transition metal of the Periodic Table of Elements, or a Period 3 transition metal of the Periodic Table of Elements.
In one or more embodiments, M1 may be iridium (Ir), platinum (Pt), osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), thulium (Tm), rhodium (Rh), palladium (Pd), or gold (Au).
In one or more embodiments, M1 may be Pt, Pd, or Au.
In Formula 1, X10, X11, X20, X30, and X40 are each independently C or N, provided that one of X10 and X11 is N, and the other of X10 and X11 is C.
In one or more embodiments, X20 and X30 may each be C, and X40 may be N.
In Formula 1, two bonds of a bond between X10 and M1, a bond between X20 and M1, a bond between X30 and M1, and a bond between X40 and M1 may be coordinate bonds, and the other two bonds may be covalent bonds. In this regard, the organometallic compound represented by Formula 1 may be electrically neutral.
In one or more embodiments, a bond between X10 and M1 in Formula 1 may be a coordinate bond.
In one or more embodiments, in Formula 1, one bond of a bond between X20 and M1, a bond between X30 and M1, and a bond between X40 and M1 may be a coordinate bond, and the other two bonds may be covalent bonds. For example, in Formula 1, a bond between X20 M1 and a bond between X30 and M1 may be covalent bonds, and a bond between X40 and M1 may be a coordinate bond.
In Formula 1, ring A10 is present or absent, and each of X12 and X13 is C when ring A10 is present, and X12 is C(R11) and X13 is C(R12) when ring A10 is not present.
In Formula 1, ring A11, which is a 5-membered ring including N, X10, X11, X12, and X13 as ring members, is a pyrazole ring or an imidazole ring.
In Formula 1, ring A10 may be absent, or ring A10 may be a C5-C30 carbocyclic group or a C1-C30 heterocyclic group.
In Formula 1, ring A20, ring A30, and ring A40 are each independently a C5-C30 carbocyclic group or a C1-C30 heterocyclic group.
In one or more embodiments, in Formula 1, ring A10, ring A20, ring A30, and ring A40 may each independently be i) a first ring, ii) a second ring, iii) a condensed ring in which two or more first rings are condensed with each other, iv) a condensed ring in which two or more second rings are condensed with each other, or v) a condensed ring in which one or more first rings and one or more second rings are condensed with each other,
For example, in Formula 1, ring A10, ring A20, ring A30, and ring A40 may each independently be a cyclopentane group, a cyclopentene group, a cyclohexane group, a cyclohexene group, a cyclohexadiene 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, a borole group, a phosphole group, a germole group, a selenophene 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-fluorene-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-fluorene-9-one group, an azadibenzothiophene 5,5-dioxide group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a 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, a 5,6,7,8-tetrahydroquinoline group, an adamantane group, a norbornane group, or a norbornene group.
In one or more embodiments, a moiety represented by
in Formula 1 may be represented by one of Formulae A10(1) to A10(4):
wherein, in Formulae A10(1) to A10(4),
In one or more embodiments, a moiety represented by
in Formula 1 may be represented by Formula A10-1, A10-2, A10(3), or A10(4):
wherein, in Formulae A10-1, A10-2, A10(3), and A10(4),
In one or more embodiments, ring A20 in Formula 1 may be represented by one of Formulae A20(1) to A20(15):
wherein, in Formulae A20(1) to A20(15),
In one or more embodiments, ring A30 in Formula 1 may be represented by one of Formulae A30(1) to A30(12):
wherein, in Formulae A30(1) to A30(12),
For example, ring A30 in Formula 1 may be represented by Formula A30(1), and accordingly, a moiety represented by
in Formula 1 may be represented by Formula A30-1:
wherein, in Formula A30-1,
For example, X31 in Formula A30-1 may be a single bond.
In one or more embodiments, ring A40 in Formula 1 may be represented by one of Formulae A40(1) to A40(34):
wherein, in Formulae A40(1) to A40(34),
In Formula 1, T1 and T2 are each independently a single bond, *—N(R51)—*′, *—B(R51)—*′ *—P(R51)—*′, *—C(R51)(R52)—*′, *—Si(R51)(R52)—*′, *—Ge(R51)(R52)—*′, *—S—*′, *—Se—*′, *—O—*′, *—C(═O)—*′, *—S(═O)—*′, *—S(═O)2—*, *—C(R51)═C(R52)—*′, *—C(═S)—*′, or *—C≡C—*′.
In Formula 1, R10 to R12, R10A, R20, R30, R40, R51, and R52 are each independently be a group represented by Formula 2, hydrogen, deuterium, —F, —Cl, —Br, —I, —SF5, a hydroxyl group, a cyano group, a nitro 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, —N(Q1)(Q2), —Si(Q3)(Q4)(Q5), —B(Q6)(Q7), —P(Q8)(Q9), or —P(═O)(Q5)(Q9), and
In one or more embodiments, R10 to R12, R10A, R20, R30, R40, R51, and R52 may each independently be:
In Formula 1, b10, b20, b30, and b40 each indicate the number of R10(s), the number of R20(s), the number of R30(s), and the number of R40(s), respectively, and are each independently an integer from 1 to 10.
In Formula 1, at least one of R10, R11, R12, R20, R30, or R40 is a group represented by Formula 2:
In one or more embodiments, L21 to L24 in Formula 2 may each independently be: 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 pyrrole group, a thiophene group, a furan group, an indole group, an indene group, a benzothiophene group, a benzofuran group, a carbazole group, a fluorene group, a dibenzothiophene group, or a dibenzofuran group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, —SF5, —CD3, —CD2H,-CDH2, —CF3, —CF2H, —CFH2, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C1-C20 alkyl group, a C1-C20 alkoxy group, a C1-C20 alkylthio group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a furanyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a benzocarbazolyl group, a benzocarbazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, —Si(Q33)(Q34)(Q35), or a combination thereof, and
In one or more embodiments, L21 to L24 in Formula 2 may each independently be:
In Formula 2, a21 to a24 re each independently an integer from 0 to 3.
In one or more embodiments, in Formula 1, a21 to a24 may each independently be 0 or 1. In one or more embodiments, in Formula 2, a21 to a23 may each independently be 0, and a24 may be 0 or 1.
In one or more embodiments, in Formula 2, R201 to R203 may each independently be 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 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, or a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group.
In one or more embodiments, in Formula 2, R201 to R203 may each independently be:
In one or more embodiments, in Formula 2, R201 to R203 may each independently be: a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isooctyl group, a sec-octyl group, a tert-octyl group, an n-nonyl group, an isononyl group, a sec-nonyl group, a tert-nonyl group, an n-decyl group, an isodecyl group, a sec-decyl group, or a tert-decyl group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, —SF5, —CD3, —CD2H,-CDH2, —CF3, —CF2H, —CFH2, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C1-C20 alkoxy group, a C1-C20 alkylthio group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, or a combination thereof; or
In Formula 2 n21 is an integer from 1 to 5.
For example, in one or more embodiments, in Formula 2, n21 may be 1 or 2.
In one or more embodiments, a compound represented by Formula 2 may be represented by Formula 2(1):
wherein, in Formula 2(1),
For example, in Formula 2(1), L24 may be a benzene group, a naphthalene group, a carbazole group, a fluorene group, a dibenzothiophene group, or a dibenzofuran group, each substituted or unsubstituted deuterium, —F, —Cl, —Br, —I, —SF5, —CD3, —CD2H, —CDH2, —CF3, —CF2H, —CFH2, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C1-C20 alkyl group, a C1-C20 alkoxy group, a C1-C20 alkylthio group, a cyclopentyl group, a cyclohexyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a carbazolyl group, a fluorenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, or a combination thereof.
In one or more embodiments, a group represented by Formula 2 may be a group represented by one of Formulae 2-1 to 2-4:
wherein, in Formulae 2-1 to 2-4,
In one or more embodiments, in Formulae 2-1 to 2-4, R201 to R203 may each independently be:
In one or more embodiments, n21 in Formula 2-2 may be 1 or 2, and n21 in Formulae 2-3 and 2-4 may be 1.
In one or more embodiments, each group represented by Formula 2 independently may be a group represented by one of Formulae 2-101 to 2-134:
wherein, in Formulae 2-101 to 2-134,
In one or more embodiments, in Formula 1, one of R10, R11, R12, R20, R30, and R40 may be a group represented by Formula 2.
In one or more embodiments, the organometallic compound may be represented by one or more of Formulae 1A to 1D:
wherein, in Formulae 1A to 1D,
In the present specification, as used herein, at least one substituent of the substituted C5-C60 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:
In the present specification, as used herein, * and *′ each indicate a binding site to a neighboring atom.
In one or more embodiments, the organometallic compound may be one or more of Compounds 1 to 218:
wherein “TMG” is a trimethyl-germyl group, and “TPG” is a triphenyl-germyl group.
The organometallic compound represented by Formula 1 may include, as a ligand substituent, at least one group represented by Formula 2. The organometallic compound may include a group represented by Formula 2 which is a bulky germanium (Ge)-containing substituent so that the emission waveform may be improved. For example, the organometallic compound may exhibit an emission spectrum having a narrow full width at half maximum (FWHM) and a small second peak intensity. Accordingly, an organic light-emitting device including the organometallic compound may have improved color purity.
In one embodiment, the organometallic compound may have an electroluminescence (EL) and/or photoluminescence (PL) spectrum that includes a first peak and a second peak, wherein the maximum emission wavelength of the second peak is greater than the maximum emission wavelength of the first peak, and the intensity of the second peak may be less than the intensity of the first peak.
In addition, when the organometallic compound represented by Formula 1 includes a bulky Ge-containing substituent and is used as an emitter of an emission layer, the formation of exciplex with a host molecule may be suppressed. Accordingly, a decrease in efficiency of an organic light-emitting device including the organometallic compound may be substantially suppressed, and thus high luminescence efficiency may be achieved.
The highest occupied molecular orbital (HOMO) energy level (electron Volts, eV), lowest unoccupied molecular orbital (LUMO) energy level (eV), lowest triplet (T1) energy level (eV), and FWHM (nm) of select organometallic compound represented by Formula 1 were evaluated by density functional theory (DFT) using the Gaussian 09 program with the molecular structure optimization obtained at the B3LYP-basis level, and results thereof are shown in Table 1.
wherein “TMG” is a trimethyl-germyl group, and “TPG” is a triphenyl-germyl group.
Referring to Table 1, it was confirmed that, as a result of molecular simulation, the organometallic compound according to one or more embodiments exhibits a relatively narrow FWHM compared to Comparative Compounds C1 and C3 to C5.
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 described below.
Accordingly, the organometallic compound represented by Formula 1 may be suitable for use as a material for an organic layer of an organic light-emitting device, for example, a material for an emission layer of the organic layer. Thus, another aspect of the present disclosure 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 and including an emission layer, wherein the organic layer includes at least one organometallic compound represented by Formula 1.
The organic light-emitting device may have, due to the inclusion of the organic layer including the organometallic compound represented by Formula 1, excellent external quantum efficiency, an emission waveform with a reduced second peak intensity, and excellent color purity.
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”.
In one or more embodiments, 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 exist in an identical layer (for example, Compound 1 and Compound 2 may all exist in the emission layer).
In one or more embodiments, the at least one organometallic compound may be included in the emission layer of the organic light-emitting device.
For example, the emission layer may further include a host, and an amount of the host in the emission layer may be greater than that of the at least one organometallic compound in the emission layer.
The emission layer may emit red light, green light, or blue light. For example, the emission layer may emit blue light having a maximum emission wavelength of about 410 nm to about 490 nm.
For example, the emission layer may have a configuration as described in First exemplary configuration or the second exemplary configuration, but embodiments are not limited thereto.
The emission layer may include the organometallic compound represented by Formula 1, and the organometallic compound represented by Formula 1 may serve as a phosphorescent emitter. For example, a ratio of a luminescent component emitted from the organometallic compound with respect to all luminescent components of the emission layer may be about 80% or greater, or about 85% or greater, or about 90% or greater, or about 95% or greater.
In one or more embodiments, light emitted from the organometallic compound may be blue light.
The emission layer may include, in addition to the organometallic compound represented by Formula 1, a phosphorescent dopant, a fluorescent dopant, or a combination thereof, which is different from the organometallic compound. In this regard, the organometallic compound may serve not as a phosphorescent emitter, but as a sensitizer or an auxiliary dopant. For example, the emission layer may further include a fluorescent dopant, and the fluorescent dopant may be different from the organometallic compound. The ratio of a luminescent component emitted from the fluorescent dopant with respect to all luminescent components of the emission layer may be about 80% or greater, or about 85% or greater, or about 90% or greater, or about 95% or greater.
In the second embodiment, an amount of the fluorescent dopant may be, based on 100 parts by weight of the organometallic compound represented by Formula 1, in a range of about 1 part by weight to about 100 parts by weight, or about 5 parts by weight to about 50 parts by weight, or about 10 parts by weight to about 20 parts by weight.
In the second embodiment, a total amount of the organometallic compound represented by Formula 1 and the fluorescent dopant may be, based on 100 parts by weight of the emission layer, in a range of about 1 part by weight to 30 parts by weight, or about 3 parts by weight to about 20 parts by weight, or about 5 parts by weight to about 15 parts by weight.
The fluorescent dopant that may be used in the second embodiment may not include a transition metal.
In the second embodiment, the emission layer may emit fluorescence generated while triplet excitons of the organometallic compound represented by Formula 1 are delivered to the fluorescent dopant and then transferred.
For example, the fluorescent dopant may include a compound represented by Formula 503-1 or 503-2:
wherein, in Formulae 503-1 and 503-2,
In one or more embodiments, 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. In one or more embodiments, 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.
In one or more embodiments, the first electrode may be an anode, the second electrode may be a cathode, and the organic layer may include a hole transport region between the first electrode and the emission layer and an electron transport region 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.
For example, the organometallic compound may be included in at least one of the hole transport region and the electron transport region.
The term “organic layer” as used herein refers to a single layer and/or a plurality of layers 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 an exemplary embodiment will be described in further detail in connection with the FIGURE.
The organic light-emitting device 10 of the FIGURE 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 1, any substrate that is used in organic light-emitting devices of the related art may be used, and for example, a glass substrate or a transparent plastic substrate, each having excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and water resistance, may be used.
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. In one or more embodiments, 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), 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 two or more layers. For example, the first electrode 11 may have a three-layered structure of ITO/Ag/ITO, but the structure of the first electrode 11 is 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 between the first electrode 11 and the emission layer.
The hole transport region may include at least one selected from a hole injection layer, a hole transport layer, an electron blocking layer, and a buffer layer.
The hole transport region may include only either a hole injection layer or a hole transport layer. 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 constituting layers for each structure 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/or Langmuir-Blodgett (L-B) 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 (A/sec) to about 100 Å/sec. However, the deposition conditions 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 properties 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. However, the coating conditions are not limited thereto.
Conditions for forming the hole transport layer and the electron blocking layer may be 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(naphthalene-1-yl)-N,N′-diphenyl-benzidine (NPB), pi-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 a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, a heptalenylene group, an acenaphthylene group, a fluorenylene group, a phenalenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylenylene group, a naphthacenylene group, a picenylene group, a perylenylene group, or a pentacenylene group, each unsubstituted or substituted with at least one of 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 C1-C60 alkyl group, a C2-C60 alkenyl group, a C2-C60 alkynyl group, a C1-C60 alkoxy group, a C1-C60 alkylthio group, a C3-C10 cycloalkyl group, a C3-C10 cycloalkenyl group, a C1-C10 heterocycloalkyl group, a C1-C10 heterocycloalkenyl group, a C6-C60 aryl group, a C7-C60 alkyl aryl group, a C7-C60 aryl alkyl group, a C1-C60 aryloxy group, a C2-C60 arylthio group, a C1-C60 heteroaryl group, a C2-C60 alkyl heteroaryl group, a C2-C60 heteroaryl alkyl group, a C1-C60 heteroaryloxy group, a C1-C60 heteroarylthio group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, or a combination thereof.
In Formula 201, xa and xb may each independently be an integer from 0 to 5, or may each independently be 0, 1, or 2. For example, xa may be 1, and xb may be 0, but xa and xb are not limited thereto.
In Formulae 201 and 202, R101 to R108, R111 to R119, and R121 to R124 may each independently be:
In Formula 201, R109 may be a phenyl group, a naphthyl group, an anthracenyl group, or a pyridinyl group, each unsubstituted or substituted with 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 C1-C20 alkyl group, a C1-C20 alkoxy group, a C1-20 alkylthio group, a phenyl group, a naphthyl group, an anthracenyl group, a pyridinyl group, or a combination thereof.
In one or more embodiments, the compound represented by Formula 201 may be represented by Formula 201A:
wherein, in Formula 201A, R101, R111, R112, and R109 may respectively be as described herein.
For example, the hole transport region may include one of Compounds HT1 to HT20, or a combination thereof:
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 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 these materials, a charge-generation material for the improvement of 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 include a quinone derivative, a metal oxide, a cyano group-containing compound, or a combination thereof, but embodiments of the present disclosure are not limited thereto. For example, non-limiting examples of the p-dopant are a quinone derivative, such as tetracyanoquinodimethane (TCNQ), 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinonedimethane (F4-TCNQ), or F6-TCNQ, a metal oxide, such as a tungsten oxide or a molybdenum oxide; or a cyano group-containing compound, such as Compounds HT-D1 and F12, but 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, and thus, efficiency of the light-emitting device may be improved.
Then, the emission layer may be formed on the hole transport region by using methods such as vacuum deposition, spin coating, casting, and/or L-B 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 although the deposition or coating conditions may vary according to a material that is used to form the hole transport layer.
The hole transport region may further include an electron blocking layer. The electron blocking layer may include a material available in the art, for example, mCP, but embodiments of the present disclosure are not limited thereto:
A thickness of the electron blocking layer may be about 50 Å to about 1,000 Å, for example about 70 Å to about 500 Å. When the thickness of the electron blocking layer is within the range described above, the electron blocking layer may have satisfactory electron blocking characteristics without a substantial increase in driving voltage.
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, based on 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.
The emission layer may include the organometallic compound represented by Formula 1.
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 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), TCP, mCP, Compound H50, Compound H51, Compound H52, or a combination thereof:
In one or more embodiments, the host may further include a compound represented by Formula 301:
wherein, in Formula 301, Ar111 and Ar112 may each independently be:
In Formula 301, Ar113 to Ar116 may each independently be:
In Formula 301, g, h, i, and j may each independently be 0, 1, 2, 3, or 4, and for example, may each independently be 0, 1, or 2.
In Formula 301, Ar113 to Ar115 may each independently be:
but embodiments are not limited thereto.
In one or more embodiments, the host may include a compound represented by Formula 302:
In Formula 302, Ar125 and Ar127 may each independently be a C1-C10 alkyl group (for example, a methyl group, an ethyl group, or a propyl group).
In Formula 302, k and l may each independently be 0, 1, 2, 3, or 4. For example, k and l may each independently be 0, 1, or 2.
When the emission layer includes both a host and a dopant, an amount of the dopant may be in a range of about 0.01 parts by weight to about 20 parts by weight based on 100 parts by weight of the host, but embodiments of the present disclosure are not limited thereto. When the amount of the dopant is within the ranges above, emission without extinction phenomenon may be implemented.
In one or more embodiments, the organic layer of the organic light-emitting device may further include, in addition to the organometallic compound represented by Formula 1, a fluorescent dopant.
For example, the fluorescent dopant may be a condensation polycyclic compound, a styryl-based compound, or a combination thereof.
In one or more embodiments, the fluorescent dopant may include a naphthalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, an indenoanthracene group, a tetracene group, a group represented by one of Formulae 501-1 to 501-21, or a combination thereof:
In one or more embodiments, the fluorescent dopant may be a compound represented by Formula 501:
For example, Ar501 in Formula 501 may be:
In one or more embodiments, the fluorescent dopant may include a compound represented by one or more of Formulae 502-1 to 502-5:
In one or more embodiments, the fluorescent dopant may include a compound represented by one or more of Formula 503-1 or 503-2:
The fluorescent dopant may include, for example, one of Compounds FD(16) and FD1 to FD17, or a combination thereof:
A thickness of the emission layer may be in a range of about 100 Å to about 1,000 Å, for example, about 200 Å to about 600 Å. When the thickness of the emission layer is within these ranges, excellent luminescence characteristics may be obtained without a substantial increase in driving voltage.
Next, the electron transport region 5 is arranged on the emission layer.
The electron transport region may include at least one selected from a hole blocking layer, an electron transport layer and an electron injection layer.
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 the structure of the electron transport region is 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 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) or 4,7-diphenyl-1,10-phenanthroline (Bphen), 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 these ranges, excellent hole-blocking characteristics may be obtained without a substantial increase in driving voltage.
In one or more embodiments, the electron transport layer may include 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), 1,3,5-tris(N-phenylbenzimidazole-2-yl)benzene (TPBi), tris(8-hydroxyquinolino)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), 4-(naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (NTAZ), or a combination thereof:
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 these ranges, 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, Compound ET-D1 (lithium quinolate (LiQ)) or ET-D2:
In one or more embodiments, the electron transport region may also include an electron injection layer that promotes the flow of electrons from the second electrode 19 thereinto.
The electron injection layer may include at least one of LiQ, LiF, NaCl, CsF, Li2O, or BaO.
A thickness of the electron injection layer may be in a range of about 1 Å to about 100 Å, and, for example, about 3 Å to about 90 Å. When the thickness of the electron injection layer is within these ranges, satisfactory electron injection characteristics may be obtained without a substantial increase in driving voltage.
The second electrode 19 is arranged on the organic layer 15. The second electrode 19 may be a cathode. A material for forming the second electrode 19 may be 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), aluminum (Al), silver (Ag), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), or magnesium-silver (Mg—Ag). To manufacture a top-emission type light-emitting device, various modifications are possible, and for example, a transmissive electrode formed using ITO or IZO may be used as the second electrode 19.
Hereinbefore, the organic light-emitting device has been described with reference to
Another aspect of the present disclosure provides a diagnostic composition including at least one organometallic compound represented by Formula 1.
The organometallic compound represented by Formula 1 provides high luminescence efficiency, and accordingly, the diagnostic composition including the at least one organometallic compound may have high diagnostic efficiency.
The diagnostic composition may be used in various applications including a diagnosis kit, a diagnosis reagent, a biosensor, and a biomarker.
Definitions of Terms
The term “C1-C60 alkyl group” as used herein refers to a linear or branched saturated aliphatic hydrocarbon monovalent group having 1 to 60 carbon atoms, and examples thereof are 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, and the like. The term “C1-C6 alkylene group” as used herein refers to a divalent group having 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 examples thereof are a methoxy group, an ethoxy group, an isopropyloxy group, and the like. The term “C1-C6 alkylthio group” as used herein refers to a monovalent group represented by —SA101 (wherein A101 is the C1-C60 alkyl group).
The term “C2-C6 alkenyl group” as used herein refers to a hydrocarbon group formed by substituting at least one carbon-carbon double bond in the middle or at the terminus of the C2-C60 alkyl group, and examples thereof are an ethenyl group, a propenyl group, a butenyl group, and 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 refers to a hydrocarbon group formed by substituting at least one carbon-carbon triple bond in the middle or at the terminus of the C2-C60 alkyl group, and examples thereof are an ethynyl group, a propynyl group, and 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 examples thereof are a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and 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 saturated monocyclic group having at least one heteroatom selected from N, O, P, Si, Se, Ge, and S as a ring-forming atom and 1 to 10 carbon atoms, and examples thereof are a tetrahydrofuranyl group, a tetrahydrothiophenyl group, and 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 monocyclic group that has 3 to 10 carbon atoms and at least one carbon-carbon double bond in the ring thereof and no aromaticity, and examples thereof are a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, and 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 monocyclic group that has at least one heteroatom selected from N, O, P, Si, Se, Ge, and S as a ring-forming atom, 1 to 10 carbon atoms, and at least one carbon-carbon double bond in its ring. Examples of the C1-C10 heterocycloalkenyl group are a 2,3-dihydrofuranyl group, a 2,3-dihydrothiophenyl group, and 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 having a carbocyclic aromatic system having 6 to 60 carbon atoms, and the term “C6-C60 arylene group” as used herein refers to a divalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms. Examples of the C6-C60 aryl group are a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, a chrysenyl group, and the like. When the C6-C60 aryl group and the C6-C60 arylene group each include two or more rings, the two or more rings may be fused to each other.
The term “C1-C6 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, Se, Ge, 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. 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, and the like. When the C6—C60 heteroaryl group and the C6-C60 heteroarylene group each include two or more rings, the two or more rings may be fused to each other.
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 —OA102, (wherein A102, is the C1-C60 heteroaryl group), and the term “C1-C60 heteroarylthio group” as used herein refers to —SA103′ (wherein A103′ is the C1-C60 heteroaryl group).
The term “C7-C60 alkyl aryl group” as used herein refers to a C1-C30 aryl group substituted with a C1-C30 alkyl group. The term “C7-C60 aryl alkyl group” as used herein refers to a C1-C30 alkyl group substituted with a C6-C30 aryl group.
The term “C2-C60 alkyl heteroaryl group” as used herein refers to a C1-C30 heteroaryl group substituted with a C1-C30 alkyl group. The term “C2-C60 heteroaryl alkyl group” as used herein refers to a C1-C30 alkyl group substituted with a C1-C30 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. Examples of the monovalent non-aromatic condensed polycyclic group are a fluorenyl group and the like. The term “divalent non-aromatic condensed polycyclic group” as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed polycyclic group described above.
The term “monovalent non-aromatic condensed heteropolycyclic group” as used herein refers to a monovalent group (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, Se, Ge, and S, other than carbon atoms, as a ring-forming atom, and no aromaticity in its entire molecular structure. Examples of the monovalent non-aromatic condensed heteropolycyclic group are a carbazolyl group and the like. The term “divalent non-aromatic condensed heteropolycyclic group” as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed heteropolycyclic group described above.
The term “C5-C30 carbocyclic group” as used herein refers to a saturated or unsaturated cyclic group having, as a ring-forming atom, 5 to 30 carbon atoms only. 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 having, as a ring-forming atom, at least one heteroatom selected from N, O, P, Si, Se, Ge, and S other than 1 to 30 carbon atoms. The C1-C30 heterocyclic group may be a monocyclic group or a polycyclic group.
At least one substituent of each 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 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:
For example, Q1 to Q9, Q11 to Q19, Q21 to Q29, and Q31 to Q39 as used herein may each independently be:
The term “room temperature” as used herein refers to a temperature of about 25° C.
The terms “a biphenyl group, a terphenyl group, and a tetraphenyl group” as used herein respectively refer to monovalent groups in which two, three, or four phenyl groups which are linked together via a single bond.
Hereinafter, a compound and an organic light-emitting device according to one or more exemplary embodiments are described in further detail with reference to Synthesis Examples and Examples. However, the compound and the organic light-emitting device 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.
(1) Synthesis of 2-(3-(1H-benzo[d]imidazol-1-yl)phenoxy)-9-(4-(tert-butyl)pyridin-2-yl)-6-chloro-9H-carbazole
1-(3-bromophenyl)-1H-benzo[d]imidazole (4.0 g, 14.65 mmol), 9-(4-(tert-butyl)pyridin-2-yl)-6-chloro-9H-carbazol-2-ol (7.19 g, 20.50 mmol), CuI (0.84 g, 4.39 mmol), Pyridine-2-carboxylic Acid (0.72 g, 5.86 mmol), and Potassium phosphate (9.33 g, 43.94 mmol) were mixed with DMSO (98 mL), and stirred at 100° C. for 12 hours. After completion of the reaction, the resultant mixture was allowed to cool to room temperature. An extraction process was performed thereon using saturated ammonium chloride (NH4Cl) aqueous solution and ethyl acetate (EA), and an organic layer extracted therefrom was dried using anhydrous magnesium sulfate (MgSO4), filtered, and then concentrated under reduced pressure. The resultant product thus obtained was subjected to silica gel flash column chromatography to obtain 2-(3-(1H-benzo[d]imidazol-1-yl)phenoxy)-9-(4-(tert-butyl)pyridin-2-yl)-6-chloro-9H-carbazole (7.5 g, yield=94%).
2-(3-(1H-benzo[d]imidazol-1-yl)phenoxy)-9-(4-(tert-butyl)pyridin-2-yl)-6-chloro-9H-carbazole (6.00 grams (g), 11.05 millimoles (mmol)), (7-(trimethylgermyl)dibenzo[b,d]furan-4-yl)boronic acid (4.72 g, 14.36 mmol), palladium (II) acetate (0.50 g, 2.21 mmol), 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl (X-phos) (1.05 g, 2.21 mmol), and cesium carbonate (7.20 g, 22.10 mmol) were mixed with 1,4-dioxane and water (3:1 v/v, 56 mL), and stirred at 100° C. for 12 hours. After completion of the reaction, the resultant mixture was allowed to cool to room temperature. An extraction process was performed thereon using saturated ammonium chloride (NH4Cl) and ethyl acetate (EA), and an organic layer extracted therefrom was dried using anhydrous magnesium sulfate (MgSO4), filtered, and then concentrated under reduced pressure. The resultant product thus obtained was subjected to silica gel flash column chromatography to obtain Intermediate 161-IM2 (7.45 g, 9.41 mmol, yield=85%).
Liquid chromatography-mass spectrometry (LS-MS) (calculated: 792.25 g/mol, found M+1=793.23 g/mol).
Intermediate 161-IM2 (4.60 g, 5.81 mmol), (3,5-di-tert-butylphenyl)(mesityl)iodonium trifluoromethanesulfonate (4.08 g, 6.97 mmol), and copper (II) acetate (0.11 g, 0.58 mmol) were mixed with 23 mL of N,N-dimethylformamide (DMF), and stirred at 100° C. for 12 hours. After completion of the reaction, the resultant mixture was allowed to cool to room temperature. An extraction process was performed thereon using saturated NH4Cl and EA, and an organic layer extracted therefrom was dried using anhydrous MgSO4, filtered, and then concentrated under reduced pressure. The resultant product thus obtained was subjected to silica gel flash column chromatography to obtain Intermediate 161-IM1 (4.49 g, 3.97 mmol, yield=68%).
LC-MS (calculated: 1130.37 g/mol, found M+=981.38 g/mol).
Intermediate 161-IM1 (4.49 g, 3.97 mmol), (1,5-cyclooctadiene)platinum(II) dichloride (Pt(COD)Cl2) (1.64 g, 4.37 mmol), and sodium acetate (0.98 g, 11.92 mmol) were mixed with 99 mL of DMF, and stirred at 150° C. for 16 hours. After completion of the reaction, the resultant mixture was allowed to cool to room temperature. An extraction process was performed thereon using saturated NH4Cl and dichloromethane (MC), and an organic layer extracted therefrom was dried using anhydrous MgSO4, filtered, and then concentrated under reduced pressure. The resultant product thus obtained was subjected to silica gel flash column chromatography to obtain Compound 161 (1.51 g, 1.28 mmol, yield=32%).
LC-MS (calculated: 1172.36 g/mol, found M+1=1173.32 g/mol).
2-(3-(1H-benzo[d]imidazol-1-yl)phenoxy)-9-(4-(tert-butyl)pyridin-2-yl)-6-chloro-9H-carbazole (5.00 g, 9.21 mmol), trimethyl(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)germane (4.43 g, 13.81 mmol), palladium (II) acetate (0.70 g, 3.68 mmol), 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl (S-phos) (0.91 g, 7.37 mmol), and potassium phosphate tribasic (5.86 g, 27.62 mmol) were mixed with 1,4-dioxane and DI water (4:1 v/v, 100 mL), and stirred at 110° C. for 20 hours. After completion of the reaction, the resultant mixture was allowed to cool to room temperature. An extraction process was performed thereon using saturated NH4Cl and EA, and an organic layer extracted therefrom was dried using anhydrous MgSO4, filtered, and then concentrated under reduced pressure. The resultant product thus obtained was subjected to silica gel flash column chromatography to obtain Intermediate 130-IM2 (3.72 g, 5.30 mmol, yield=58%).
LC-MS (calculated: 702.24 g/mol, found M+1=703.23 g/mol).
Intermediate 130-IM2 (3.72 g, 5.30 mmol), (3,5-di-tert-butylphenyl)(mesityl)iodonium trifluoromethanesulfonate (4.65 g, 7.95 mmol), and copper (II) acetate (0.10 g, 0.53 mmol) were mixed with 21 mL of DMF, and stirred at 100° C. for 3 hours. After completion of the reaction, the resultant mixture was allowed to cool to room temperature. An extraction process was performed thereon using saturated NH4Cl and EA, and an organic layer extracted therefrom was dried using anhydrous MgSO4, filtered, and then concentrated under reduced pressure. The resultant product thus obtained was subjected to silica gel flash column chromatography to obtain Intermediate 130-IM1 (3.53 g, 3.39 mmol, yield=64%).
LC-MS (calculated: 1040.36 g/mol, found M+=891.38 g/mol).
Intermediate 130-IM1 (3.53 g, 3.39 mmol), Pt(COD)C12 (1.40 g, 3.73 mmol), and sodium acetate (0.84 g, 10.18 mmol) were mixed with 85 mL of DMF, and stirred at 150° C. for 18 hours. After completion of the reaction, the resultant mixture was cooled to room temperature. An extraction process was performed thereon using saturated NH4Cl and MC, and an organic layer extracted therefrom was dried using anhydrous MgSO4, filtered, and then concentrated under reduced pressure. The resultant product thus obtained was subjected to silica gel flash column chromatography to obtain Compound 130 (1.22 g, 1.12 mmol, yield=33%).
LC-MS (calculated: 1083.35 g/mol, found M=1083.32 g/mol).
A sample was prepared by diluting Compound 161 in toluene at a concentration of 1×10−4 M. A PL spectrum of the sample was measured at room temperature (25° C.) by using an ISC PC1 spectrofluorometer equipped with a Xenon lamp. Then, a similar process was repeated for each of Compound 130 and Comparative Compound C1, and a maximum PL emission wavelength (λmax, nm), full width at half maximum (FWHM, nm), and second peak intensity (arbitrary units, AU) of each compound are shown in Table 2.
As shown in Table 2, it was observed that Compounds 130 and 161 according to the exemplary embodiments showed PL spectra having FWHM that was less than or equal to the FWHM in PL spectra of Comparative Compound C1, and Compounds 130 and 161 showed a decrease in the second peak intensity. Accordingly, it was confirmed that the exemplary compounds exhibiting a maximum emission wavelength in a blue light wavelength region had optical properties suitable for emission of deep blue light.
A glass substrate with a 500 Å-thick indium tin oxide (ITO) electrode (first electrode, anode) formed thereon was cleaned by ultrasonication using DI water. After washing with DI water, ultrasonication was performed thereon using isopropyl alcohol, acetone, and methanol in this stated order, and then, the resultant glass substrate was dried and transferred to a plasma cleaner. The glass substrate was cleaned using oxygen plasma for 5 minutes, and then transferred to a vacuum laminator.
Compound HT3 was vacuum-deposited on the ITO electrode surface of the glass substrate to form a first hole injection layer having a thickness of 3,500 Å, Compound HT-D1 was vacuum-deposited on the first hole injection layer to form a second hole injection layer having a thickness of 300 Å, and TAPC was vacuum-deposited on the second hole injection layer to form an electron blocking layer having a thickness of 100 Å, thereby forming a hole transport region.
Compound H52 as a host and Compound 161 as an emitter were co-deposited at an emitter concentration of 13 wt % on the hole transport region to form an emission layer having a thickness of 300 Å.
Compound ET3 was vacuum-deposited on the emission layer to form an electron transport layer having a thickness of 250 Å, ET-D1 (LiQ) was deposited on the electron transport layer to form an electron injection layer having a thickness of 5 Å, and an Al second electrode (cathode) having a thickness of 1,000 Å was formed on the electron injection layer, thereby completing the manufacture of an organic light-emitting device.
Organic light-emitting devices were manufactured in a similar manner as in Example 1, except that, in forming an emission layer, for use as an emitter, corresponding compounds shown in Table 3 were used instead of Compound 161.
For each of the organic light-emitting devices manufactured according to Examples 1 and 2 and Comparative Example 1, a maximum emission wavelength (λmax, nm), FWHM (nm), CIE color y-coordinate (CIEy), and external quantum efficiency (EQE, %) were evaluated, and results are shown in Table 3. Details for measuring the maximum emission wavelength and the EQE were as follows.
Regarding the organic light-emitting devices manufactured herein, the maximum emission wavelength results were obtained from electroluminescence (EL) spectra at luminance of 1,000 candela per square meter (cd/m2 or nits) by using a luminance meter (Minolta Cs-1000A).
The EQE results were obtained at luminance of 1,000 cd/m2 by using a current-voltmeter (Keithley 2400) and a luminance meter (Minolta Cs-1000A).
Referring to Table 3, the organic light-emitting devices of Examples 1 and 2 had narrow FWHM and small CIEy and improved EQE, as compared to the organic light-emitting device of Comparative Example 1 using a compound not including a Ge-containing group as an emitter. Accordingly, it was confirmed that the compound of the present disclosure had optical properties suitable for emission of deep blue light.
An organic light-emitting device was manufactured in a similar manner as in Example 1, except that, in forming an emission layer, 1.5 wt % of FD17 was used as an emitter and 10 wt % of Compound 161 was used as a sensitizer.
An organic light-emitting device was manufactured in a similar manner as in Example 1, except that, in forming an emission layer, 1.5 wt % of FD17 was used as an emitter and 10 wt % of Compound 130 was used as a sensitizer.
An organic light-emitting device was manufactured in a similar manner as in Example 1, except that, in forming an emission layer, 1.5 wt % of FD17 was used as an emitter and 10 wt % of Compound C1 was used as a sensitizer.
For each of the organic light-emitting devices manufactured according to Examples 3 and 4 and Comparative Example 2, a maximum luminescence wavelength (λmax, nm), FWHM (nm), and EQE (%) were evaluated, and results are shown in Table 4.
Referring to Table 4, the organic light-emitting devices of Examples 3 and 4 using the organometallic compound according to one or more embodiments as a sensitizer in the emission layer had excellent CIEy color coordinates and slightly increased EQE, as compared to the organic light-emitting device of Comparative Example 2. Accordingly, it was found that, when the organometallic compound according one or more embodiments was applied to the emission layer, the energy transfer to a fluorescent dopant occurred smoothly so that the EQE could be improved.
As described above, according to the one or more embodiments, an organometallic compound represented by Formula 1 exhibits an emission spectrum having a narrow full width at half maximum and a small second peak intensity. Thus, when applied to an organic light-emitting device, emission of deep blue may be implemented by improving color purity.
It should be understood that embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments. While one or more embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2021-0096715 | Jul 2021 | KR | national |
