LIGHT-EMITTING DEVICE AND ELECTRONIC APPARATUS INCLUDING SAME

CROSS-REFERENCE TO RELATED APPLICATION

This application is based on and claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2021-0031483, filed on Mar. 10, 2021, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety.

BACKGROUND
1. Field

Provided are a light-emitting device and an electronic apparatus including the same.

2. Description of the Related Art

Organic light-emitting devices (OLEDs), from among light-emitting devices, are self-emissive devices which produce full-color images. In addition, OLEDs have wide viewing angles and exhibit excellent driving voltage and response speed characteristics.

OLEDs include an anode, a cathode, and an organic layer between the anode and the cathode and including an emission layer. A hole transport region may be between the anode and the emission layer, and an electron transport region may be between the emission layer and the cathode. Holes provided from the anode may move toward the emission layer through the hole transport region, and electrons provided from the cathode may move toward the emission layer through the electron transport region. The holes and the electrons recombine in the emission layer to produce excitons. The excitons may transition from an excited state to a ground state, thus generating light.

SUMMARY

The present disclosure relates to a light-emitting device including a novel emission layer and an electronic apparatus including the light-emitting device.

Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments of the disclosure.

According to an aspect of an embodiment, an organic light-emitting device includes

a first electrode,

a second electrode facing the first electrode, and

an emission layer between the first electrode and the second electrode,

wherein the emission layer includes i) a first emission layer and ii) a second emission layer between the first emission layer and the second electrode,

the first emission layer may be in direct contact with the second emission layer,

the first emission layer includes a first dopant, a first hole-transporting compound, and a first electron-transporting compound,

the second emission layer includes a second dopant, a second hole-transporting compound, and a second electron-transporting compound,

the first dopant is identical to the second dopant,

the first electron-transporting compound is different from the second electron-transporting compound,

the electron mobility of the second electron-transporting compound is greater than electron mobility of the first electron-transporting compound, and

the electron mobility of the first electron-transporting compound and the electron mobility of the second electron-transporting compound may respectively be evaluated by using a time versus current graph of a time of flight (TOF) device including the first electron-transporting compound or the second electron-transporting compound.

According to an aspect of another embodiment, an electronic apparatus may include the light-emitting device.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of certain embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a graph of thickness of an emission layer (x-axis) versus an exciton concentration profile (y-axis) in an exemplary embodiment of a light-emitting device;

FIG. 2 is a schematic cross-sectional view of an organic light-emitting device according to an exemplary embodiment; and

FIG. 3 is a graph of time versus current graph of TOF (E1-62) and TOF (E1-63).

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described 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 associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.

It will be understood that when an element is referred to as being “on” another element, it can be directly on the other element or intervening elements may be present therebetween. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present.

It will be understood that, although the terms “first,” “second,” “third” etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, “a first element,” “component,” “region,” “layer” or “section” discussed below could be termed a second element, component, region, layer or section without departing from the teachings herein.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, “a,” “an,” “the,” and “at least one” do not denote a limitation of quantity, and are intended to cover both the singular and plural, unless the context clearly indicates otherwise. For example, “an element” has the same meaning as “at least one element,” unless the context clearly indicates otherwise.

“Or” means “and/or.” As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. It will be further understood that the terms “comprises” and/or “comprising,” or “includes” and/or “including” when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof.

Furthermore, relative terms, such as “lower” or “bottom” and “upper” or “top,” may be used herein to describe one element's relationship to another element as illustrated in the Figures. It will be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures. For example, if the device in one of the figures is turned over, elements described as being on the “lower” side of other elements would then be oriented on “upper” sides of the other elements. The exemplary term “lower,” can therefore, encompasses both an orientation of “lower” and “upper,” depending on the particular orientation of the figure. Similarly, if the device in one of the figures is turned over, elements described as “below” or “beneath” other elements would then be oriented “above” the other elements. The exemplary terms “below” or “beneath” can, therefore, encompass both an orientation of above and below.

“About” or “approximately” as used herein is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with measurement of the particular quantity (i.e., the limitations of the measurement system). For example, “about” can mean within one or more standard deviations, or within ±30%, 20%, 10% or 5% of the stated value.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Exemplary embodiments are described herein with reference to cross section illustrations that are schematic illustrations of idealized embodiments. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments described herein should not be construed as limited to the particular shapes of regions as illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, a region illustrated or described as flat may, typically, have rough and/or nonlinear features. Moreover, sharp angles that are illustrated may be rounded. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the precise shape of a region and are not intended to limit the scope of the present claims.

The light-emitting device may include: a first electrode; a second electrode facing the first electrode; and an emission layer between the first electrode and the second electrode, wherein the emission layer may include i) a first emission layer and ii) a second emission layer between the first emission layer and the second electrode.

The first emission layer may be in direct contact with the second emission layer.

The first emission layer may include a first dopant, a first hole-transporting compound, and a first electron-transporting compound, and the second emission layer may include a second dopant, a second hole-transporting compound, and a second electron-transporting compound.

The first dopant, the first hole-transporting compound, and the first electron-transporting compound included in the first emission layer may be different from each other.

The second dopant, the second hole-transporting compound, and the second electron-transporting compound included in the second emission layer may be different from each other.

A total weight of the first hole-transporting compound and the first electron-transporting compound in the first emission layer may be greater than a weight of the first dopant in the first emission layer.

In an embodiment, the first emission layer may include a dopant and a host (for example, a weight of the host may be greater than a weight of the dopant in the first emission layer), the dopant may include the first dopant, and the host may include the first hole-transporting compound and the first electron-transporting compound.

A total weight of the second hole-transporting compound and the second electron-transporting compound in the second emission layer may be greater than a weight of the second dopant in the second emission layer.

In an embodiment, the second emission layer may include a dopant and a host (for example, a weight of the host may be greater than a weight of the dopant in the second emission layer), the dopant may include the second dopant, and the host may include the second hole-transporting compound and the second electron-transporting compound.

In one or more embodiments, the first emission layer may include a mixture including the first dopant, the first hole-transporting compound, and the first electron-transporting compound. In one or more embodiments, the first emission layer may include a single layer including a mixture including the first dopant, the first hole-transporting compound, and the first electron-transporting compound. In one or more embodiments, the first emission layer may be formed by co-deposition of the first dopant, the first hole-transporting compound, and the first electron-transporting compound.

In one or more embodiments, the second emission layer may include a mixture including the second dopant, the second hole-transporting compound, and the second electron-transporting compound. In one or more embodiments, the second emission layer may include a single layer including a mixture including the second dopant, the second hole-transporting compound, and the second electron-transporting compound. In one or more embodiments, the second emission layer may be formed by co-deposition of second dopant, the second hole-transporting compound, and the second electron-transporting compound.

The first dopant included in the first emission layer may be identical to the second dopant included in the second emission layer. The first dopant and the second dopant may respectively be understood by referring to the descriptions of the first dopant and the second dopant provided herein.

In an embodiment, the first dopant and the second dopant may each be a phosphorescent dopant.

In one or more embodiments, the first dopant and the second dopant may each be a transition metal-containing organometallic compound.

In one or more embodiments, the first dopant and the second dopant may each be a heteroleptic transition metal-containing organometallic compound.

In one or more embodiments, the first dopant and the second dopant may each be an organometallic compound represented by Formula 1. Formula 1 may be understood by referring to the description of Formula 1 provided herein.

In one or more embodiments, the first dopant and the second dopant may each be a transition metal-containing organometallic compound, and the transition metal-containing organometallic compound may include a pyridine group, a benzimidazole group (or a naphthoimidazole group), and/or a dibenzofuran group (or an azadibenzofuran group, a dibenzothiophene group, or an azadibenzothiophene group). The pyridine group and the benzimidazole group (or the naphthoimidazole group) may each be bound to the transition metal of the transition metal-containing organometallic compound via a nitrogen atom, and the dibenzofuran group (or the azadibenzofuran group, the dibenzothiophene group, or the azadibenzothiophene group) may each be bound to the transition metal of the transition metal-containing organometallic compound via a carbon atom. The pyridine group, the benzimidazole group (or the naphthoimidazole group), and the dibenzofuran group (or the azadibenzofuran group, the dibenzothiophene group, or the azadibenzothiophene group) may optionally be substituted with at least one R₁. R₁may be understood by referring to the description of R₁in Formula 1.

In one or more embodiments, the first dopant and the second dopant may each be a transition metal-containing organometallic compound, and the transition metal-containing organometallic compound may include a pyridine group, a benzimidazole group (or a naphthoimidazole group), a benzene group, and/or a dibenzofuran group (or an azadibenzofuran group, a dibenzothiophene group, or an azadibenzothiophene group). The pyridine group and the benzimidazole group (or the naphthoimidazole group) may each be bound to the transition metal of the transition metal-containing organometallic compound via a nitrogen atom, and the benzene group and the dibenzofuran group (or the azadibenzofuran group, the dibenzothiophene group, or the azadibenzothiophene group) may each be bound to the transition metal of the transition metal-containing organometallic compound via a carbon atom. The pyridine group, the benzimidazole group (or the naphthoimidazole group), the benzene group, and the dibenzofuran group (or the azadibenzofuran group, the dibenzothiophene group, or the azadibenzothiophene group) may optionally be substituted with at least one R₁. R₁may be understood by referring to the description of R₁in Formula 1.

In one or more embodiments, the first dopant and the second dopant may each be a transition metal-containing organometallic compound, and the transition metal-containing organometallic compound may include a group represented by —Si(Q₃)(Q₄)(Q₅), a group represented by —Ge(Q₃)(Q₄)(Q₅), or any combination thereof. The —Si(Q₃)(Q₄)(Q₅) group and the —Ge(Q₃)(Q₄)(Q₅) group may respectively be understood by referring to the descriptions of —Si(Q₃)(Q₄)(Q₅) and —Ge(Q₃)(Q₄)(Q₅) in Formula 1.

In one or more embodiments, an absolute value of a highest occupied molecular orbital (HOMO) energy level of each of the first dopant and the second dopant may be smaller than each of an absolute value of a HOMO energy level of the first hole-transporting compound, an absolute value of a HOMO energy level of the second hole-transporting compound, an absolute value of a HOMO energy level of the first electron-transporting compound, and an absolute value of a HOMO energy level of the second electron-transporting compound. For example, the HOMO energy level may be a negative value as an actual measurement value measured by using a photoelectron spectrometer in an atmospheric pressure.

In one or more embodiments, a HOMO energy level of the first dopant and the second dopant may be in a range of about −5.60 eV to about −5.20 eV.

In an embodiment, the first hole-transporting compound included in the first emission layer may be identical to the second hole-transporting compound included in the second emission layer.

In one or more embodiments, the first hole-transporting compound included in the first emission layer may be different from the second hole-transporting compound included in the second emission layer.

The first hole-transporting compound and the second hole-transporting compound may respectively be understood by referring to the descriptions of the first hole-transporting compound and the second hole-transporting compound provided herein.

The first hole-transporting compound and the second hole-transporting compound may each be a compound i) including at least one π electron-rich C₃-C₆₀cyclic group (e.g., a carbazole group, an indolocarbazole group, or a benzene group) and ii) not including an electron-transporting group. Examples of the electron-transporting group may include a cyano group, a fluoro group, a π electron-depleted nitrogen-containing C₁-C₆₀cyclic group, a phosphine oxide group, and a sulfoxide group.

In an embodiment, the first hole-transporting compound and the second hole-transporting compound may each be a compound represented by Formula 5. Formula 5 may be understood by referring to the description of Formula 5 provided herein.

In an embodiment, the first electron-transporting compound included in the first emission layer may be different from the second electron-transporting compound included in the second emission layer.

For example, the first electron-transporting compound and the second electron-transporting compound may each be a compound including at least one electron-transporting group. The electron-transporting group may be a cyano group, a fluoro group, a π electron-depleted nitrogen-containing C₁-C₆₀cyclic group, a phosphine oxide group, a sulfoxide group, or any combination thereof.

In an embodiment, the first electron-transporting compound and the second electron-transporting compound may each be a compound represented by Formula 7. Formula 7 may be understood by referring to the description of Formula 7 provided herein.

The electron mobility of the second electron-transporting compound may be greater than the electron mobility of the first electron-transporting compound.

The electron mobility of the first electron-transporting compound and the electron mobility of the second electron-transporting compound may respectively be evaluated by using a time versus current graph of a time of flight (TOF) device including the first electron-transporting compound or the second electron-transporting compound.

In an embodiment, the TOF device may include a pair of electrodes and a first film between the pair of electrodes, and the first film may consist of the first electron-transporting compound or the second electron-transporting compound.

The pair of electrodes may be a pair of conductive electrodes. For example, the pair of electrodes may be an indium tin oxide (ITO) electrode and an aluminum (Al) electrode, an ITO electrode and a silver (Ag) electrode, or an ITO electrode and a magnesium (Mg) electrode.

The first film may be formed by deposition. A thickness of the first film may be, for example, about 0.1 micrometers (μm) to about 5 μm.

The electron mobility of the first electron-transporting compound and the electron mobility of the second electron-transporting compound may each be calculated according to Equation 100:

$\begin{matrix} μ = \frac{d^{2}}{tV} & Equation 100 \end{matrix}$

wherein, in Equation 100,

μ indicates the electron mobility of a compound of which electron mobility is measured,

d indicates the thickness of a film including the compound of which electron mobility is measured (that is, the first film of the TOF device),

t indicates the electron migration time evaluated from a time versus current graph of the TOF device including the compound of which electron mobility is measured, and

V indicates the voltage applied to the TOF device including the compound of which electron mobility is measured.

In an embodiment, in Equation 100, “t” may be the time corresponding to the intersection point of two tangent lines in the time versus current graph (e.g., a log-log scale) of the TOF device (e.g., the tangent line in FIG. 3) (e.g., Harvey Scher and Elliott W. Montroll. Phys. Rev. B 12, 2455 (1975)).

For example, a method of evaluating the electron mobility may be understood by referring to the description of Evaluation Example 1 provided herein.

In an embodiment, the electron mobility of the second electron-transporting compound may be about 110% or greater, about 110% to about 1,000%, about 110% to about 500%, about 110% to about 300%, about 110% to about 200%, about 130% to about 210%, about 150% to about 220%, about 170% to about 230%, about 180% to about 240%, or about 190% to about 250% of the electron mobility of the first electron-transporting compound.

In one or more embodiments, the electron mobility of the second electron-transporting compound may be about 2.0×10⁻⁵cm²/Vs or greater, or for example, about 2.0×10⁻⁵cm²/Vs to about 5.0×10⁻⁵cm²/Vs, about 2.2×10⁻⁵cm²/Vs to about 4.5×10⁻⁵cm²/Vs, about 2.4×10⁻⁵cm²/Vs to about 4.0×10⁻⁵cm²/Vs, about 2.6×10⁻⁵cm²/Vs to about 3.0×10⁻⁵cm²/Vs, or about 2.8×10⁻⁵cm²/Vs to about 3.2×10⁻⁵cm²/Vs.

In one or more embodiments, the electron mobility of the first electron-transporting compound may be less than about 2.8×10⁻⁵cm²/Vs, or for example, about 1.0×10⁻⁵cm²/Vs to about 2.7×10⁻⁵cm²/Vs, about 1.1×10⁻⁵cm²/Vs to about 2.2×10⁻⁵cm²/Vs, about 1.2×10⁻⁵cm²/Vs to about 1.8×10⁻⁵cm²/Vs, or about 1.3×10⁻⁵cm²/Vs to about 1.6×10⁻⁵cm²/Vs.

In one or more embodiments, the electron mobility of the first electron-transporting compound may be about 2.0×10⁻⁵cm²/Vs or less, or for example, about 1.8×10⁻⁵cm²/Vs or less, about 1.0×10⁻⁵cm²/Vs to about 2.0×10⁻⁵cm²/Vs, or about 1.2×10⁻⁵cm²/Vs to about 1.6×10⁻⁵cm²/Vs.

As described above, when the electron mobility of the second electron-transporting compound is greater than the electron mobility of the first electron-transporting compound, resistance may not be generated between the first hole-transporting compound and the second hole-transporting compound, and resistance of the light-emitting device may be reduced due to the second electron-transporting compound (having relatively high electron mobility), thereby improving the driving voltage of the light-emitting device. In addition, an exciton recombination zone in the emission layer may have a relatively narrow width, and thus, an exciton recombination rate in the emission layer may increase, thereby improving luminescence efficiency of the light-emitting device. At the same time, due to the first electron-transporting compound (having relatively low electron mobility), the exciton recombination zone may be spaced apart from the interface between the hole transport region and the emission layer by a predetermined distance, thereby improving lifespan characteristics of the light-emitting device. Accordingly, the driving voltage of the light-emitting device including the emission layer may be reduced, and thus, luminescence efficiency and lifespan characteristics of the light-emitting device may be increased.

FIG. 1 is a graph of thickness of an emission layer (x-axis) versus an exciton concentration profile (y-axis) in a light-emitting device. The hatched area indicates the exciton recombination zone.

The x-axis in FIG. 1 indicates the thickness of the emission layer, and when i) the light-emitting device further includes 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, ii) a thickness of the first emission layer is D₁nanometers (nm), and iii) a thickness of the second emission layer is D₂nm, the interface between the hole transport region and the first emission layer in the x-axis in FIG. 1 may be at 0 nm, and the interface between the second emission layer and the electron transport region may be at D₁+D₂nm.

In an embodiment, the light-emitting device may satisfy at least one of Conditions 1 to 3, and Conditions 1 to 3 may be understood by referring to FIG. 1:

Condition 1

70% or greater of the exciton recombination zone may be formed in the first emission layer of the emission layer,

Condition 2

the full width at half maximum (FWHM) of the exciton concentration profile in the emission layer may be 0.1×D₁nm to 0.7×D₁nm, and D₁may be the thickness of the first emission layer, and

Condition 3

a hole transport region may be between the first electrode and the emission layer, and

a maximum value of the exciton concentration in the emission layer may be present in an area of 0.5×D₁nm to D₁nm from the interface between the hole transport region and the emission layer to inside the emission layer, and D₁indicates thickness of the first emission layer.

In one or more embodiments, the light-emitting device may satisfy Equation 1:

Con(HT1)>Con(ET1) Equation 1

wherein, in Equation 1,

Con(HT1) indicates the parts by weight of the first hole-transporting compound, based on 100 parts by weight of the total weight of the first dopant, the first hole-transporting compound, and the first electron-transporting compound, and

Con(ET1) indicates the parts by weight of the first electron-transporting compound, based on 100 parts by weight of the total weight of the first dopant, the first hole-transporting compound, and the first electron-transporting compound.

In one or more embodiments, a ratio of Con(HT1) to Con(ET1) may be in a range of about 8:2 to about 5.2:4.8.

In one or more embodiments, the light-emitting device may satisfy Equation 2:

Con(HT2)>Con(ET2) Equation 2

wherein, in Equation 2,

Con(HT2) indicates the parts by weight of the second hole-transporting compound, based on 100 parts by weight of the total weight of the second dopant, the second hole-transporting compound, and the second electron-transporting compound, and

Con(ET2) indicates the parts by weight of the second electron-transporting compound, based on 100 parts by weight of the total weight of the second dopant, the second hole-transporting compound, and the second electron-transporting compound.

In one or more embodiments, a ratio of Con(HT2) to Con(ET2) may be in a range of about 8:2 to about 5.2:4.8.

In one or more embodiments, the light-emitting device may satisfy Equation 3:

Con(ET2)>Con(ET1) Equation 3

wherein, in Equation 3,

In one or more embodiments, the light-emitting device may satisfy Equation 4:

Con(ET2)<Con(ET1) Equation 4

wherein, in Equation 4,

In one or more embodiments, a ratio of a thickness of the second emission layer to a thickness of the first emission layer may be in a range of about 9:1 to about 1:9, or for example, about 2:8 to about 8:2.

In one or more embodiments, light which may be emitted from the emission layer and passed through at least one of the first electrode and the second electrode to the outside of the device may be green light having a maximum emission wavelength (emission peak wavelength) in a range of about 500 nm to about 580 nm.

In one or more embodiments, the light-emitting device may further include a hole transport region between the first electrode and the emission layer, wherein the hole transport region may not include a charge-generation layer and an 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.

In one or more embodiments, the light-emitting device may further include an electron transport region between the emission layer and the second electrode, wherein the electron transport region may not include a charge-generation layer and an emission layer. The electron transport region may include a hole blocking layer, an electron transport layer, an electron injection layer, or a combination thereof.

In one or more embodiments, the emission layer may not include a compound of Group A:

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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 some 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.

Description for Formula 1

M(L₁)_n1(L₂)_n2 Formula 1

In Formula 1, M may be a transition metal.

In some embodiments, M may be a first-row transition metal, a second-row transition metal, or a third-row transition metal.

In some embodiments, M may be iridium (Ir), platinum (Pt), osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), thulium (Tm), or rhodium (Rh).

In an embodiment, M may be Ir, Pt, Os, or Rh.

In Formula 1, L₁may be a ligand represented by Formula 2A, and L₂may be a ligand represented by Formula 2B:

embedded image

Formulae 2A and 2B may respectively be understood by referring to the descriptions of Formulae 2A and 2B provided herein.

n1 in Formula 1 may be 1, 2, or 3, and when n1 is 2 or greater, at least two L₁(s) may be identical to or different from each other.

In Formula 1, n2 may be 0, 1, or 2, and when n2 is 2, two L₂(s) may be identical to or different from each other.

In Formula 1, the sum of n1 and n2 may be 2 or 3. For example, a sum of n1 and n2 may be 3.

In some embodiments, in Formula 1, i) M may be Ir, and n1+n2=3, or ii) M may be Pt, and n1+n2=2.

In one or more embodiments, in Formula 1, M may be Ir, and i) n1 may be 1, and n2 may be 2, or ii) n1 may be 2, and n2 may be 1.

L₁and L₂in Formula 1 may be different from each other.

In Formulae 2A to 2B, Y₁to Y₄may each independently be C or N. For example, Y₁and Y₃may each be N, and Y₂and Y₄may each be C.

In Formulae 2A and 2B, ring CY₁to ring CY₄may each independently be a C₅-C₃₀carbocyclic group or a C₁-C₃₀heterocyclic group.

In some embodiments, ring CY₁to ring CY₄may each independently include i) a third ring, ii) a fourth ring, iii) a condensed ring in which at least two third rings are condensed, iv) a condensed ring in which at least two fourth rings are condensed, or v) a condensed ring in which at least one third ring is condensed with at least one fourth ring,

the third ring may be a cyclopentane group, a cyclopentene group, a furan group, a thiophene group, a pyrrole group, a silole group, a borole group, a phosphole group, a germole group, a selenophene group, an oxazole group, an oxadiazole group, an oxatriazole group, a thiazole group, a thiadiazole group, a thiatriazole group, a pyrazole group, an imidazole group, a triazole group, a tetrazole group, or an azasilole group, and

the fourth ring may be an adamantane group, a norbornane group, a norbornene group, a cyclohexane group, a cyclohexene group, a benzene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, or a triazine group.

In an embodiment, ring CY₁to ring CY₄may each independently be a cyclopentane group, a cyclohexane group, a cyclohexene group, a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a 1,2,3,4-tetrahydronaphthalene group, a cyclopentadiene group, a pyrrole group, a furan group, a thiophene group, a silole group, a borole group, a phosphole group, a germole group, a selenophene group, an indene group, an indole group, a benzofuran group, a benzothiophene group, a benzosilole group, a benzoborole group, a benzophosphole group, a benzogermole group, a benzoselenophene group, a fluorene group, a carbazole group, a dibenzofuran group, a dibenzothiophene group, a dibenzosilole group, a dibenzoborole group, a dibenzophosphole group, a dibenzogermole group, a dibenzoselenophene group, a benzofluorene group, a benzocarbazole group, a naphthobenzofuran group, a naphthobenzothiophene group, a naphthobenzosilole group, a naphthobenzoborole group, a naphthobenzophosphole group, a naphthobenzogermole group, a naphthobenzoselenophene group, a dibenzofluorene group, a dibenzocarbazole group, a dinaphthofuran group, a dinaphthothiophene group, a dinaphthosilole group, a dinaphthoborole group, a dinaphthophosphole group, a dinaphthogermole group, a dinaphthoselenophene group, an indenophenanthrene group, an indolophenanthrene group, a phenanthrobenzofuran group, a phenanthrobenzothiophene group, a phenanthrobenzosilole group, a phenanthrobenzoborole group, a phenanthrobenzophosphole group, a phenanthrobenzogermole group, a phenanthrobenzoselenophene group, a dibenzothiophene 5-oxide group, a 9H-fluorene-9-one group, a dibenzothiophene 5,5-dioxide group, an azaindene group, an azaindole group, an azabenzofuran group, an azabenzothiophene group, an azabenzosilole group, an azabenzoborole group, an azabenzophosphole group, an azabenzogermole group, an azabenzoselenophene group, an azafluorene group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, an azadibenzosilole group, an azadibenzoborole group, an azadibenzophosphole group, an azadibenzogermole group, an azadibenzoselenophene group, an azabenzofluorene group, an azabenzocarbazole group, an azanaphthobenzofuran group, an azanaphthobenzothiophene group, an azanaphthobenzosilole group, an azanaphthobenzoborole group, an azanaphthobenzophosphole group, an azanaphthobenzogermole group, an azanaphthobenzoselenophene group, an azadibenzofluorene group, an azadibenzocarbazole group, an azadinaphthofuran group, an azadinaphthothiophene group, an azadinaphthosilole group, an azadinaphthoborole group, an azadinaphthophosphole group, an azadinaphthogermole group, an azadinaphthoselenophene group, an azaindenophenanthrene group, an azaindolophenanthrene group, an azaphenanthrobenzofuran group, an azaphenanthrobenzothiophene group, an azaphenanthrobenzosilole group, an azaphenanthrobenzoborole group, an azaphenanthrobenzophosphole group, an azaphenanthrobenzogermole group, an azaphenanthrobenzoselenophene group, an azadibenzothiophene 5-oxide group, an aza9H-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 benzoquinoline group, a benzoisoquinoline group, a benzoquinoxaline group, a benzoquinazoline group, a phenanthroline group, a phenanthridine group, a pyrrole group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isooxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, an azasilole group, an azaborole group, an azaphosphole group, an azagermole group, an azaselenophene group, a benzopyrrole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzisoxazole group, a benzothiazole group, a benzoisothiazole group, a benzoxadiazole group, a benzothiadiazole group, a pyridinopyrrole group, a pyridinopyrazole group, a pyridinoimidazole group, a pyridinooxazole group, a pyridinoisoxazole group, a pyridinothiazole group, a pyridinoisothiazole group, a pyridinooxadiazole group, a pyridinothiadiazole group, a pyrimidinopyrrole group, a pyrimidinopyrazole group, a pyrimidinoimidazole group, a pyrimidinooxazole group, a pyrimidinoisoxazole group, a pyrimidinothiazole group, a pyrimidinoisothiazole group, a pyrimidinooxadiazole group, a pyrimidinothiadiazole group, a 5,6,7,8-tetrahydroisoquinoline group, a 5,6,7,8-tetrahydroquinoline group, an adamantane group, a norbornane group, a norbornene group, a benzene group condensed with a cyclohexane group, a benzene group condensed with a norbornane group, a pyridine group condensed with a cyclohexane group, or a pyridine group condensed with a norbornane group.

In an embodiment, ring CY₁may be an azaindene group, an azaindole group, an azabenzofuran group, an azabenzothiophene group, an azabenzosilole group, an azabenzoborole group, an azabenzophosphole group, an azabenzogermole group, an azabenzoselenophene group, an azafluorene group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, an azadibenzosilole group, an azadibenzoborole group, an azadibenzophosphole group, an azadibenzogermole group, an azadibenzoselenophene group, an azabenzofluorene group, an azabenzocarbazole group, an azanaphthobenzofuran group, an azanaphthobenzothiophene group, an azanaphthobenzosilole group, an azanaphthobenzoborole group, an azanaphthobenzophosphole group, an azanaphthobenzogermole group, an azanaphthobenzoselenophene group, an azadibenzofluorene group, an azadibenzocarbazole group, an azadinaphthofuran group, an azadinaphthothiophene group, an azadinaphthosilole group, an azadinaphthoborole group, an azadinaphthophosphole group, an azadinaphthogermole group, an azadinaphthoselenophene group, an azaindenophenanthrene group, an azaindolophenanthrene group, an azaphenanthrobenzofuran group, an azaphenanthrobenzothiophene group, an azaphenanthrobenzosilole group, an azaphenanthrobenzoborole group, an azaphenanthrobenzophosphole group, an azaphenanthrobenzogermole group, an azaphenanthrobenzoselenophene group, an azadibenzothiophene 5-oxide group, an aza9H-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 benzoquinoline group, a benzoisoquinoline group, a benzoquinoxaline group, a benzoquinazoline group, a phenanthroline group, a phenanthridine group, a pyrrole group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isooxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, an azasilole group, an azaborole group, an azaphosphole group, an azagermole group, an azaselenophene group, a benzopyrrole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzisoxazole group, a benzothiazole group, a benzoisothiazole group, a benzoxadiazole group, a benzothiadiazole group, a pyridinopyrrole group, a pyridinopyrazole group, a pyridinoimidazole group, a pyridinooxazole group, a pyridinoisoxazole group, a pyridinothiazole group, a pyridinoisothiazole group, a pyridinooxadiazole group, a pyridinothiadiazole group, a pyrimidinopyrrole group, a pyrimidinopyrazole group, a pyrimidinoimidazole group, a pyrimidinooxazole group, a pyrimidinoisoxazole group, a pyrimidinothiazole group, a pyrimidinoisothiazole group, a pyrimidinooxadiazole group, a pyrimidinothiadiazole group, a 5,6,7,8-tetrahydroisoquinoline group, a 5,6,7,8-tetrahydroquinoline group, a pyridine group condensed with a cyclohexane group, or a pyridine group condensed with a norbornane group.

In one or more embodiments, ring CY₂and CY₄may each independently be a cyclopentane group, a cyclohexane group, a cyclohexene group, a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a 1,2,3,4-tetrahydronaphthalene group, a cyclopentadiene group, a pyrrole group, a furan group, a thiophene group, a silole group, a borole group, a phosphole group, a germole group, a selenophene group, an indene group, an indole group, a benzofuran group, a benzothiophene group, a benzosilole group, a benzoborole group, a benzophosphole group, a benzogermole group, a benzoselenophene group, a fluorene group, a carbazole group, a dibenzofuran group, a dibenzothiophene group, a dibenzosilole group, a dibenzoborole group, a dibenzophosphole group, a dibenzogermole group, a dibenzoselenophene group, a benzofluorene group, a benzocarbazole group, a naphthobenzofuran group, a naphthobenzothiophene group, a naphthobenzosilole group, a naphthobenzoborole group, a naphthobenzophosphole group, a naphthobenzogermole group, a naphthobenzoselenophene group, a dibenzofluorene group, a dibenzocarbazole group, a dinaphthofuran group, a dinaphthothiophene group, a dinaphthosilole group, a dinaphthoborole group, a dinaphthophosphole group, a dinaphthogermole group, a dinaphthoselenophene group, an indenophenanthrene group, an indolophenanthrene group, a phenanthrobenzofuran group, a phenanthrobenzothiophene group, a phenanthrobenzosilole group, a phenanthrobenzoborole group, a phenanthrobenzophosphole group, a phenanthrobenzogermole group, a phenanthrobenzoselenophene group, a dibenzothiophene 5-oxide group, a 9H-fluorene-9-one group, a dibenzothiophene 5,5-dioxide group, an azaindene group, an azaindole group, an azabenzofuran group, an azabenzothiophene group, an azabenzosilole group, an azabenzoborole group, an azabenzophosphole group, an azabenzogermole group, an azabenzoselenophene group, an azafluorene group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, an azadibenzosilole group, an azadibenzoborole group, an azadibenzophosphole group, an azadibenzogermole group, an azadibenzoselenophene group, an azabenzofluorene group, an azabenzocarbazole group, an azanaphthobenzofuran group, an azanaphthobenzothiophene group, an azanaphthobenzosilole group, an azanaphthobenzoborole group, an azanaphthobenzophosphole group, an azanaphthobenzogermole group, an azanaphthobenzoselenophene group, an azadibenzofluorene group, an azadibenzocarbazole group, an azadinaphthofuran group, an azadinaphthothiophene group, an azadinaphthosilole group, an azadinaphthoborole group, an azadinaphthophosphole group, an azadinaphthogermole group, an azadinaphthoselenophene group, an azaindenophenanthrene group, an azaindolophenanthrene group, an azaphenanthrobenzofuran group, an azaphenanthrobenzothiophene group, an azaphenanthrobenzosilole group, an azaphenanthrobenzoborole group, an azaphenanthrobenzophosphole group, an azaphenanthrobenzogermole group, an azaphenanthrobenzoselenophene group, an azadibenzothiophene 5-oxide group, an aza9H-fluorene-9-one group, an azadibenzothiophene 5,5-dioxide group, a pyridine group, an adamantane group, a norbornane group, a norbornene group, a benzene group condensed with a cyclohexane group, or a benzene group condensed with a norbornane group.

In one or more embodiments, ring CY₃may be an azaindene group, an azaindole group, an azabenzofuran group, an azabenzothiophene group, an azabenzosilole group, an azabenzoborole group, an azabenzophosphole group, an azabenzogermole group, an azabenzoselenophene group, an azafluorene group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, an azadibenzosilole group, an azadibenzoborole group, an azadibenzophosphole group, an azadibenzogermole group, an azadibenzoselenophene group, an azabenzofluorene group, an azabenzocarbazole group, an azanaphthobenzofuran group, an azanaphthobenzothiophene group, an azanaphthobenzosilole group, an azanaphthobenzoborole group, an azanaphthobenzophosphole group, an azanaphthobenzogermole group, an azanaphthobenzoselenophene group, an azadibenzofluorene group, an azadibenzocarbazole group, an azadinaphthofuran group, an azadinaphthothiophene group, an azadinaphthosilole group, an azadinaphthoborole group, an azadinaphthophosphole group, an azadinaphthogermole group, an azadinaphthoselenophene group, an azaindenophenanthrene group, an azaindolophenanthrene group, an azaphenanthrobenzofuran group, an azaphenanthrobenzothiophene group, an azaphenanthrobenzosilole group, an azaphenanthrobenzoborole group, an azaphenanthrobenzophosphole group, an azaphenanthrobenzogermole group, an azaphenanthrobenzoselenophene group, an azadibenzothiophene 5-oxide group, an aza9H-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 benzoquinoline group, a benzoisoquinoline group, a benzoquinoxaline group, a benzoquinazoline group, a phenanthroline group, a phenanthridine group, a 5,6,7,8-tetrahydroquinoline group, a pyridine group condensed with a cyclohexane group, or a pyridine group condensed with a norbornane group.

In one or more embodiments, ring CY₁of Formula 2A may be a pyridine group, a benzimidazole group, a pyridinoimidazole group, or a pyrimidinoimidazole group.

In one or more embodiments, ring CY₂in Formula 2A may be a fluorene group, a carbazole group, a dibenzofuran group, a dibenzothiophene group, a dibenzosilole group, a dibenzoborole group, a dibenzophosphole group, a dibenzogermole group, a dibenzoselenophene group, a benzofluorene group, a benzocarbazole group, a naphthobenzofuran group, a naphthobenzothiophene group, a naphthobenzosilole group, a naphthobenzoborole group, a naphthobenzophosphole group, a naphthobenzogermole group, a naphthobenzoselenophene group, a dibenzofluorene group, a dibenzocarbazole group, a dinaphthofuran group, a dinaphthothiophene group, a dinaphthosilole group, a dinaphthoborole group, a dinaphthophosphole group, a dinaphthogermole group, a dinaphthoselenophene group, an indenophenanthrene group, an indolophenanthrene group, a phenanthrobenzofuran group, a phenanthrobenzothiophene group, a phenanthrobenzosilole group, a phenanthrobenzoborole group, a phenanthrobenzophosphole group, a phenanthrobenzogermole group, a phenanthrobenzoselenophene group, an azafluorene group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, an azadibenzosilole group, an azadibenzoborole group, an azadibenzophosphole group, an azadibenzogermole group, an azadibenzoselenophene group, an azabenzofluorene group, an azabenzocarbazole group, an azanaphthobenzofuran group, an azanaphthobenzothiophene group, an azanaphthobenzosilole group, an azanaphthobenzoborole group, an azanaphthobenzophosphole group, an azanaphthobenzogermole group, an azanaphthobenzoselenophene group, an azadibenzofluorene group, an azadibenzocarbazole group, an azadinaphthofuran group, an azadinaphthothiophene group, an azadinaphthosilole group, an azadinaphthoborole group, an azadinaphthophosphole group, an azadinaphthogermole group, an azadinaphthoselenophene group, an azaindenophenanthrene group, an azaindolophenanthrene group, an azaphenanthrobenzofuran group, an azaphenanthrobenzothiophene group, an azaphenanthrobenzosilole group, an azaphenanthrobenzoborole group, an azaphenanthrobenzophosphole group, an azaphenanthrobenzogermole group, or an azaphenanthrobenzoselenophene group.

In one or more embodiments, ring CY₃of Formula 2B may be a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a 5,6,7,8-tetrahydroquinoline group, a pyridine group condensed with a cyclohexane group, or a pyridine group condensed with a norbornane group.

In one or more embodiments, ring CY₄of Formula 2B may be a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a 1,2,3,4-tetrahydronaphthalene group, a benzene group condensed with a cyclohexane group, or a benzene group condensed with a norbornane group.

For example, in Formulae 2A and 2B, ring CY₁may be different from ring CY₃.

For example, in Formulae 2A and 2B, ring CY₂may be different from ring CY₄.

For example, in Formulae 2A and 2B, ring CY₁to ring CY₄may be different from each other.

In Formulae 2A and 2B, R₁to R₄may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, —SF₅, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C₁-C₆₀alkyl group, a substituted or unsubstituted C₂-C₆₀alkenyl group, a substituted or unsubstituted C₂-C₆₀alkynyl group, a substituted or unsubstituted C₁-C₆₀alkoxy group, a substituted or unsubstituted C₁-C₆₀alkylthio group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀arylthio group, a substituted or unsubstituted C₁-C₆₀heteroaryl 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), —Ge(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), —P(═O)(Q₈)(Q₉), or —P(Q₈)(Q₉). Q₁to Q₉may respectively be understood by referring to the descriptions of Q₁to Q₉provided herein.

In an embodiment, in Formulae 2A and 2B, R₁to R₄may each independently be:

hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, —SF₅, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, or a C₁-C₂₀alkylthio group;

a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, or a C₁-C₂₀alkylthio group, each substituted with deuterium, —F, —Cl, —Br, —I, —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-C₁₀alkyl 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 bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl group, a bicyclo[2.2.2]octyl group, a (C₁-C₂₀alkyl)cyclopentyl group, a (C₁-C₂₀alkyl)cyclohexyl group, a (C₁-C₂₀alkyl)cycloheptyl group, a (C₁-C₂₀alkyl)cyclooctyl group, a (C₁-C₂₀alkyl)adamantanyl group, a (C₁-C₂₀alkyl)norbornanyl group, a (C₁-C₂₀alkyl)norbornenyl group, a (C₁-C₂₀alkyl)cyclopentenyl group, a (C₁-C₂₀alkyl)cyclohexenyl group, a (C₁-C₂₀alkyl)cycloheptenyl group, a (C₁-C₂₀alkyl)bicyclo[1.1.1]pentyl group, a (C₁-C₂₀alkyl)bicyclo[2.1.1]hexyl group, a (C₁-C₂₀alkyl)bicyclo[2.2.2]octyl group, a phenyl group, a (C₁-C₂₀alkyl)phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, or any combination thereof;

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 bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl group, a bicyclo[2.2.2]octyl group, a phenyl group, a (C₁-C₂₀alkyl)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 purinyl 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 benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzoisothiazolyl group, a benzoxazolyl group, a benzoisoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolyl group, an azadibenzofuranyl group, or an azadibenzothiophenyl group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, —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-C₂₀alkyl group, a (phenyl)C₁-C₁₀alkyl group, a C₁-C₂₀alkoxy 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 bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl group, a bicyclo[2.2.2]octyl group, a (C₁-C₂₀alkyl)cyclopentyl group, a (C₁-C₂₀alkyl)cyclohexyl group, a (C₁-C₂₀alkyl)cycloheptyl group, a (C₁-C₂₀alkyl)cyclooctyl group, a (C₁-C₂₀alkyl)adamantanyl group, a (C₁-C₂₀alkyl)norbornanyl group, a (C₁-C₂₀alkyl)norbornenyl group, a (C₁-C₂₀alkyl)cyclopentenyl group, a (C₁-C₂₀alkyl)cyclohexenyl group, a (C₁-C₂₀alkyl)cycloheptenyl group, a (C₁-C₂₀alkyl)bicyclo[1.1.1]pentyl group, a (C₁-C₂₀alkyl)bicyclo[2.1.1]hexyl group, a (C₁-C₂₀alkyl)bicyclo[2.2.2]octyl group, a phenyl group, a (C₁-C₂₀alkyl)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 purinyl 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 benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzoisothiazolyl group, a benzoxazolyl group, a benzoisoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, or any combination thereof; or —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —Ge(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), —P(═O)(Q₈)(Q₉), or —P(Q₈)(Q₉),

wherein Q₁to Q₉may each independently be:

—CH₃, —CD₃, —CD₂H, —CDH₂, —CH₂CH₃, —CH₂CD₃, —CH₂CD₂H, —CH₂CDH₂, —CHDCH₃, —CHDCD₂H, —CHDCDH₂, —CHDCD₃, —CD₂CD₃, —CD₂CD₂H, or —CD₂CDH₂; or

an n-propyl group, an iso-propyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a tert-pentyl group, a neopentyl group, an isopentyl group, a sec-pentyl group, a 3-pentyl group, a sec-isopentyl group, a phenyl group, a biphenyl group, or a naphthyl group, each unsubstituted or substituted with deuterium, a C₁-C₁₀alkyl group, a phenyl group, or any combination thereof.

In one or more embodiments, R₁to R₄may each independently be:

hydrogen, deuterium, —F, or a cyano group;

a C₁-C₂₀alkyl group unsubstituted or substituted with deuterium, a cyano group, a C₃-C₁₀cycloalkyl group, a deuterated C₃-C₁₀cycloalkyl group, a fluorinated C₃-C₁₀cycloalkyl group, a (C₁-C₂₀alkyl)C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a deuterated heterocycloalkyl group, a fluorinated C₁-C₁₀heterocycloalkyl group, a (C₁-C₂₀heterocycloalkyl group, a phenyl group, a deuterated phenyl group, a fluorinated phenyl group, a (C₁-C₂₀alkyl)phenyl group, a biphenyl group, a deuterated biphenyl group, a fluorinated biphenyl group, a (C₁-C₂₀alkyl)biphenyl group, a dibenzofuranyl group, a deuterated dibenzofuranyl group, a fluorinated dibenzofuranyl group, a (C₁-C₂₀alkyl)dibenzofuranyl group, a dibenzothiophenyl group, a deuterated dibenzothiophenyl group, a fluorinated dibenzothiophenyl group, a (C₁-C₂₀alkyl)dibenzothiophenyl group, or any combination thereof;

a C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a phenyl group, or a biphenyl group, each unsubstituted or substituted with deuterium, a cyano group, a C₁-C₂₀alkyl group, a deuterated C₁-C₂₀alkyl group, a fluorinated C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a deuterated C₁-C₂₀alkoxy group, a fluorinated C₁-C₂₀alkoxy group, a C₃-C₁₀cycloalkyl group, a deuterated C₃-C₁₀cycloalkyl group, a fluorinated C₃-C₁₀cycloalkyl group, a (C₁-C₂₀alkyl)C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a deuterated heterocycloalkyl group, a fluorinated C₁-C₁₀heterocycloalkyl group, a (C₁-C₂₀alkyl)C₁-C₁₀heterocycloalkyl group, a phenyl group, a deuterated phenyl group, a fluorinated phenyl group, a (C₁-C₂₀alkyl)phenyl group, a biphenyl group, a deuterated biphenyl group, a fluorinated biphenyl group, a (C₁-C₂₀alkyl)biphenyl group, a dibenzofuranyl group, a deuterated dibenzofuranyl group, a fluorinated dibenzofuranyl group, a (C₁-C₂₀alkyl)dibenzofuranyl group, a dibenzothiophenyl group, a deuterated dibenzothiophenyl group, a fluorinated dibenzothiophenyl group, a (C₁-C₂₀alkyl)dibenzothiophenyl group, or any combination thereof; or

—Si(Q₃)(Q₄)(Q₅) or —Ge(Q₃)(Q₄)(Q₅).

In Formulae 2A and 2B, b1 to b4 may respectively indicate the number of R₁(s) to R₄(s), and b1 and b2 may each independently be an integer from 0 to 20. When b1 is 2 or greater, at least two R₁(s) may be identical to or different from each other, when b2 is 2 or greater, at least two R₂(s) may be identical to or different from each other, when b3 is 2 is or greater, at least two R₃(s) may be identical to or different from each other, and when b4 is 2 is or greater, at least two R₄(s) may be identical to or different from each other. In some embodiments, b1 to b4 may each independently be an integer from 0 to 8.

In an embodiment, n2 in Formula 1 may not be 0, b3 in Formula 2B may not be 0, and at least one of R₃(s) in the number of b3 may be —Si(Q₃)(Q₄)(Q₅) or —Ge(Q₃)(Q₄)(Q₅). Q₃to Q₅may respectively be understood by referring to the descriptions of Q₃to Q₅provided herein.

In some embodiments, Q₃to Q₅may each independently be:

a C₁-C₆₀alkyl group unsubstituted or substituted with deuterium, a C₁-C₆₀alkyl group, a C₆-C₆₀aryl group, or any combination thereof; or

a C₁-C₆₀aryl group unsubstituted or substituted with deuterium, a C₆-C₆₀alkyl group, a C₆-C₆₀aryl group, or any combination thereof.

In some embodiments, Q₃to Q₅may each independently be:

In an embodiment, Q₃to Q₅may be identical to one another.

In one or more embodiments, at least two of Q₃to Q₅may be different from one another.

In one or more embodiments, the organometallic compound represented by Formula 1 may include at least one deuterium.

In one or more embodiments, the organometallic compound represented by Formula 1 may satisfy at least one of Conditions (1) to (8):

Condition (1)

wherein, in Formula 2A, b1 may not be 0, and at least one of R₁(s) in the number of b1 may include deuterium,

Condition (2)

wherein, in Formula 2A, b2 may not be 0, and at least one of R₂(s) in the number of b2 may include deuterium,

Condition (3)

wherein, in Formula 2B, b3 may not be 0, and at least one of R₃(s) in the number of b3 may include deuterium,

Condition (4)

wherein, in Formula 2B, b4 may not be 0, and at least one of R₄(s) in the number of b4 may include deuterium,

Condition (5)

wherein, in Formula 2A, b1 may not be 0, and at least one of R₁(s) in the number of b1 may include a fluoro group,

Condition (6)

wherein, in Formula 2A, b2 may not be 0, and at least one of R₂(s) in the number of b2 may include a fluoro group,

Condition (7)

wherein, in Formula 2B, b3 may not be 0, and at least one of R₃(s) in the number of b3 may include a fluoro group,

Condition (8)

wherein, in Formula 2B, b4 may not be 0, and at least one of R₄(s) in the number of b4 may include a fluoro group.

In one or more embodiments, in Formulae 2A and 2B, R₁to R₄may each independently be hydrogen, deuterium, —F, a cyano group, a nitro group, —SF₅, —CH₃, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, —OCH₃, —OCDH₂, —OCD₂H, —OCD₃, —SCH₃, —SCDH₂, —SCD₂H, —SCD₃, a group represented by one of Formulae 9-1 to 9-39, a group represented by one of Formulae 9-1 to 9-39 in which at least one hydrogen is substituted with deuterium, a group represented by one of Formulae 9-1 to 9-39 in which at least one hydrogen is substituted with —F, a group represented by one of Formulae 9-201 to 9-230, a group represented by one of Formulae 9-201 to 9-230 in which at least one hydrogen is substituted with deuterium, a group represented by one of Formulae 9-201 to 9-230 in which at least one hydrogen is substituted with —F, a group represented by one of Formulae 10-1 to 10-145, a group represented by one of Formulae 10-1 to 10-145 in which at least one hydrogen is substituted with deuterium, a group represented by one of Formulae 10-1 to 10-145 in which at least one hydrogen is substituted with —F, a group represented by one of Formulae 10-201 to 10-354, a group represented by one of Formulae 10-201 to 10-354 in which at least one hydrogen is substituted with deuterium, a group represented by one of Formulae 10-201 to 10-354 in which at least one hydrogen is substituted with —F, —Si(Q₃)(Q₄)(Q₅), or —Ge(Q₃)(Q₄)(Q₅), wherein Q₃to Q₅may respectively be understood by referring to the descriptions of Q₃to Q₅provided herein:

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In Formulae 9-1 to 9-39, 9-201 to 9-230, 10-1 to 10-145, and 10-201 to 10-354, * indicates a binding site to an adjacent atom, “Ph” represents a phenyl group, “TMS” represents a trimethylsilyl group, “TMG” represents a trimethylgermyl group, and “OMe” represents a methoxy group.

The “group represented by one of Formulae 9-1 to 9-39 in which at least one hydrogen is substituted with deuterium” and the “group represented by one of Formulae 9-201 to 9-230 in which at least one hydrogen is substituted with deuterium” may each be, for example, a group represented by one of Formulae 9-501 to 9-514 and 9-601 to 9-637:

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The “group represented by one of Formulae 9-1 to 9-39 in which at least one hydrogen is substituted with —F” and the “group represented by one of Formulae 9-201 to 9-230 in which at least one hydrogen is substituted with —F” may each be, for example, a group represented by one of Formulae 9-701 to 9-710:

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The “group represented by one of Formulae 10-1 to 10-145 in which at least one hydrogen is substituted with a deuterium” and the “group represented by one of Formulae 10-201 to 10-354 in which at least one hydrogen is substituted with deuterium” may each be, for example, a group represented by one of Formulae 10-501 to 10-553:

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The “group represented by one of Formulae 10-1 to 10-145 in which at least one hydrogen is substituted with —F” and the “group represented by one of Formulae 10-201 to 10-354 in which at least one hydrogen is substituted with —F” may each be, for example, a group represented by one of Formulae 10-601 to 10-636:

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In Formulae 2A and 2B, i) at least two of a plurality of R₁(s) may optionally be bound to form a C₅-C₃₀carbocyclic group unsubstituted or substituted with at least one R_10aor a C₁-C₃₀heterocyclic group unsubstituted or substituted with at least one R_10a, ii) at least two of a plurality of R₂(s) may optionally be bound to from a C₅-C₃₀carbocyclic group unsubstituted or substituted with at least one R_10aor a C₁-C₃₀heterocyclic group unsubstituted or substituted with at least one R_10a, iii) at least two of a plurality of R₃(s) may optionally be bound to form a C₅-C₃₀carbocyclic group unsubstituted or substituted with at least one R_10aor a C₁-C₃₀heterocyclic group unsubstituted or substituted with at least one R_10a, and iv) at least two of a plurality of R₄(s) may optionally be bound to form a C₅-C₃₀carbocyclic group unsubstituted or substituted with at least one R_10aor a C₁-C₃₀heterocyclic group unsubstituted or substituted with at least one R_10a. R_10amay be understood by referring to the descriptions for R₁provided herein.

* and *′ in Formulae 2A and 2B each indicate a binding site to M in Formula 1.

In an embodiment, in Formula 2A, a group represented by

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may be represented by one of Formulae CY1(1) to CY1(42):

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wherein, in Formulae CY1(1) to CY1(42),

X₁₉may be O, S, N(R_19a), C(R_19a)(R_19b), or Si(R_19a)(R_19b), and R_19aand R_19bmay each be understood by referring to the description of R₁provided herein, and

* indicates a binding site to M in Formula 1, and *″ indicates a binding site to an adjacent carbon atom in Formula 2A.

For example, in Formula 2A, a group represented by

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may be represented by one of Formulae CY1(1) to CY1(22).

In some embodiments, in Formula 2A, a group represented by

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may be represented by one of Formulae CY1(23) to CY1(42).

In one or more embodiments, in Formula 2A, a group represented by

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may be represented by one of Formulae CY2(1) to CY2(40):

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wherein, in Formulae CY2(1) to CY2(40),

T₁to T₈may each be carbon or nitrogen,

X₂₉may be O, S, N(R_29a), C(R_29a)(R_29b), or Si(R_29a)(R_29b), and R_29aand R_29bmay each be understood by referring to the description of R₂provided herein, and

*′ indicates a binding site to M in Formula 1, and *″ indicates a binding site to ring CY₁in Formula 2A.

For example, in Formulae CY2(17) to CY2(40), T₁to T₈may each be carbon.

In some embodiments,

at least one of T₃to T₈in Formula CY2(17) may be nitrogen,

at least one of T₃, T₄, T₇, and T₈in Formula CY2(18) may be nitrogen,

at least one of T₃, T₄, T₅, and T₈in Formula CY2(19) may be nitrogen,

at least one of T₃, T₄, T₅, and T₆in Formula CY2(20) may be nitrogen,

at least one of T₁, T₂, T₅, T₆, T₇and T₈in Formula CY2(21) may be nitrogen,

at least one of T₁, T₂, T₇, and T₈in Formula CY2(22) may be nitrogen,

at least one of T₁, T₂, T₅, and T₈in Formula CY2(23) may be nitrogen,

at least one of T₁, T₂, T₅, and T₆in Formula CY2(24) may be nitrogen,

at least one of T₁, T₄, T₅, T₆, T₇and T₈in Formula CY2(25) may be nitrogen,

at least one of T₁, T₄, T₇, and T₈in Formula CY2(26) may be nitrogen,

at least one of T₁, T₄, T₅, and T₈in Formula CY2(27) may be nitrogen,

at least one of T₁, T₄, T₅, and T₆in Formula CY2(28) may be nitrogen,

at least one of T₂, T₄, T₅, T₆, T₇and T₈in Formula CY2(29) may be nitrogen,

at least one of T₂, T₄, T₇, and T₈in Formula CY2(30) may be nitrogen,

at least one of T₂, T₄, T₅, and T₈in Formula CY2(31) may be nitrogen,

at least one of T₂, T₄, T₅, and T₆in Formula CY2(32) may be nitrogen,

at least one of T₁, T₂, T₅, T₆, T₇and T₈in Formula CY2(33) may be nitrogen,

at least one of T₁, T₂, T₇, and T₈in Formula CY2(34) may be nitrogen,

at least one of T₁, T₂, T₅, and T₈in Formula CY2(35) may be nitrogen,

at least one of T₁, T₂, T₅, and T₆in Formula CY2(36) may be nitrogen,

at least one of T₃to T₈in Formula CY2(37) may be nitrogen,

at least one of T₃, T₄, T₇, and T₈in Formula CY2(38) may be nitrogen,

at least one of T₃, T₄, T₈, and T₈in Formula CY2(39) may be nitrogen, or

at least one of T₃to T₆in Formula CY2(40) may be nitrogen.

In some embodiments, in Formulae CY2(17) to CY2(40), T₈may be N, and T₁to T₇may each be carbon.

In some embodiments, in Formula 2A, a group represented by

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may be represented by one of Formulae CY2(17) to CY2(40).

In one or more embodiments, in Formula 2B, a group represented by

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may be a group represented by Formula CY3(1):

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wherein, in Formula CY3(1),

X₃₁may be Si or Ge,

R₃and Q₃to Q₅may respectively be understood by referring to the descriptions of R₃and Q₃to Q₅provided herein,

b33 may each independently be an integer from 0 to 3,

at least two of R₃(s) in the number of b33 may optionally be bound to each other to form a C₅-C₃₀carbocyclic group unsubstituted or substituted with at least one R_10aor a C₁-C₃₀heterocyclic group unsubstituted or substituted with at least one R_10a(e.g., a cyclohexane group, a norbornane group, a benzene group, a pyridine group, a naphthalene group, a quinoline group, or an isoquinoline group, each unsubstituted or substituted with at least one R_10a),

* indicates a binding site to M in Formula 1, and

*″ indicates a binding site to ring CY₄in Formula 2B.

For example, in Formula CY3(1), at least one of R₃(s) in the number of b33 may include at least two carbon atoms.

In one or more embodiments, in Formula 2B, a group represented by

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may be represented by one of Formulae CY3-1 to CY3-16:

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wherein, in Formulae CY3-1 to CY3-16,

R₃₁to R₃₄may each be understood by referring to the description of R₃provided herein, wherein R₃₁to R₃₄may each not be hydrogen,

* indicates a binding site to M in Formula 1, and

*″ indicates a binding site to ring CY₄in Formula 2B.

For example, in Formulae CY3-1 to CY3-16, R₃₂may be a C₁-C₁₀alkyl group substituted with at least one deuterium; —Si(Q₃)(Q₄)(Q₅); or —Ge(Q₃)(Q₄)(Q₅).

In some embodiments, in Formulae CY3-1 to CY3-16, R₃₃may include at least two carbon atoms.

In some embodiments, in Formulae CY3-1 to CY3-16, R₃₃and R₃₄may optionally be bound to each other to form a C₅-C₃₀carbocyclic group unsubstituted or substituted with at least one R_10aor a C₁-C₃₀heterocyclic group unsubstituted or substituted with at least one R_10a(e.g., a cyclohexane group, a norbornane group, a benzene group, a pyridine group, a naphthalene group, a quinoline group, or an isoquinoline group, each unsubstituted or substituted with at least one R_10a).

In some embodiments, in Formula 2B, a group represented by

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may be a group represented by Formula CY3-3, CY3-6, CY3-9, CY3-10, CY3-12, CY3-13, CY3-15, or CY3-16, and R₃₂in Formulae CY3-3, CY3-6, CY3-9, CY3-10, CY3-12, CY3-13, CY3-15, and CY3-16 may be —Si(Q₃)(Q₄)(Q₅) or —Ge(Q₃)(Q₄)(Q₅).

In one or more embodiments, in Formula 2B, a group represented by

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may be represented by one of Formulae CY4-1 to CY4-16:

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wherein, in Formulae CY4-1 to CY4-16,

R₄₁to R₄₄may each be understood by referring to the description of R₄provided herein, wherein R₄₁to R₄₄may each not be hydrogen,

- ′ indicates a binding site to M in Formula 1, and
- ″ indicates a binding site to ring CY₃in Formula 2B.

In an embodiment, the organometallic compound represented by Formula 1 may emit green light having a maximum emission wavelength in a range of about 500 nm to about 580 nm (in a photoluminescence (PL) spectrum).

In one or more embodiments, the organometallic compound represented by Formula 1 may satisfy Condition 1 or Condition 2:

Condition 1

wherein, in Formula 2A, a group represented by

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may be represented by one of Formulae CY1(1) to CY1(22),

in Formula 2A, a group represented by

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may be represented by one of Formulae CY2(17) to CY2(40),

in Formula 2B, a group represented by

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may be a group represented by Formula CY3(1) (for example, a group represented by Formula CY3-3, CY3-6, CY3-9, CY3-10, CY3-12, CY3-13, CY3-15, or CY3-16, wherein R₃₂may be —Si(Q₃)(Q₄)(Q₅) or —Ge(Q₃)(Q₄)(Q₅)), and

in Formula 2B, a group represented by

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may be represented by one of Formulae CY4-1 to CY4-16, and

Condition 2

wherein, in Formula 2A, a group represented by

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may be represented by one of Formulae CY1(23) to CY1(42),

in Formula 2A, a group represented by

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may be represented by one of Formulae CY2(17) to CY2(40),

in Formula 2B, a group represented by

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may be represented by Formula CY3(1) (for example, a group represented by Formula CY3-3, CY3-6, CY3-9, CY3-10, CY3-12, CY3-13, CY3-15, or CY3-16, wherein R₃₂may be —Si(Q₃)(Q₄)(Q₅) or —Ge(Q₃)(Q₄)(Q₅)), and

in Formula 2B, a group represented by

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may be represented by one of Formulae CY4-1 to CY4-16.

Description for Formulae 5 and 7

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In Formulae 5 and 7, Ar₁, Ar₂, and Ar₁₁may each independently be a C₅-C₆₀carbocyclic group unsubstituted or substituted with at least one R₅₀or a C₁-C₆₀heterocyclic group unsubstituted or substituted with at least one R₅₀.

In Formulae 5 and 7, Ar₅and Ar₁₂may each independently be a single bond, a C₅-C₆₀carbocyclic group unsubstituted or substituted with at least one R_50a, or a C₁-C₆₀heterocyclic group unsubstituted or substituted with at least one R_50a, or Ar₅and Ar₁₂may not be present.

In Formula 5, n6 may be 1, 2, or 3, and when n6 is 1, Ar₅may not be present.

In Formula 7, p may be 1, 2, or 3, and when p is 1, Ar₁₂may not be present.

In Formula 5, a1 and a2 may each independently be an integer from 0 to 5, and the sum of a1 and a2 may be 1 or greater.

In Formula 5, ring CY₅₁, and ring CY₅₂may each independently be a C₅-C₆₀carbocyclic group or a C₁-C₆₀heterocyclic group, and ring CY₅₁and ring CY₅₂may optionally be bound to each other via a C₅-C₆₀carbocyclic group unsubstituted or substituted with at least one R_50bor a C₁-C₆₀heterocyclic group unsubstituted or substituted with at least one R_50b.

In Formula 5, L₅may be a single bond, O, S, N(R_50c), C(R_50c)(R_50d), or Si(R_50c)(R_50d), n5 may be 0 or 1, and when n5 is 0, L₅may not be present,

In Formula 7, Het1 may be a π electron-depleted nitrogen-containing C₁-C₆₀cyclic group.

In Formula 7, a11 and m may each independently be an integer from 1 to 10.

The term “π electron-depleted nitrogen-containing C₁-C₆₀cyclic group” used herein refers to a cyclic group having 1 to 60 carbon atoms including at least one *—N═*′ as a ring-forming moiety, and may be, for example, a) a first ring, b) a condensed ring in which at least two first rings are condensed with each other, or c) a condensed ring in which at least one first ring is condensed with at least one second ring. The first ring and the second ring may respectively be understood by referring to the descriptions of the first ring and the second ring provided herein.

The π electron-depleted nitrogen-containing C₁-C₆₀cyclic group may be, for example, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyridazine group, a pyrimidine group, an indazole group, a purine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a phthalazine group, a naphthyridine group, a quinoxaline group, a benzoquinoxaline group, a quinazoline group, a cinnoline group, a phenanthridine group, an acridine group, a phenanthroline group, a phenazine group, a benzimidazole group, an isobenzothiazole group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a thiadiazole group, an imidazopyridine group, an imidazopyrimidine group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, an azadibenzosilole group, a benzonaphthofuran group, a benzonapthothiophene group, an (indolo)phenanthrene group, a (benzofurano)phenanthrene group, a (benzothieno)phenanthrene group, or a pyridopyrazine group.

The term “π electron-rich C₃-C₆₀cyclic group” used herein refers to a cyclic group having 3 to 60 carbon atoms not including *—N═*′ as a ring-forming moiety, and may be, for example, a) a second ring or b) a condensed cyclic group in which at least two second rings are condensed with each other. The second ring may be understood by referring to the description of the second ring provided herein.

The π electron-rich C₃-C₆₀cyclic group may be, for example, a benzene group, a heptalene group, an indene group, a naphthalene group, an azulene group, an indacene group, acenaphthylene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentacene group, a hexacene group, a pentaphene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a furan group, a thiophene group, an isoindole group, an indole group, an indene group, a benzofuran group, a benzothiophene group, a benzosilole group, a naphthopyrrole group, a naphthofuran group, a naphthothiophene group, a naphthosilole group, a benzocarbazole group, a dibenzocarbazole group, a dibenzofuran group, a dibenzothiophene group, a dibenzothiophene sulfone group, a carbazole group, a dibenzosilole group, an indenocarbazole group, an indolocarbazole group, a benzofurocarbazole group, a benzothienocarbazole group, a benzosilolocarbazole group, a triindolobenzene group, an acridine group, dihydroacridine group, a pyrrolophenanthrene group, a furanophenanthrene group, or a thienophenanthrene group.

In some embodiments,

Ar₁, Ar₂, and Ar₁₁in Formulae 5 and 7 may each independently be a group derived from i) a first ring unsubstituted or substituted with at least one R₅₀, ii) a second ring unsubstituted or substituted with at least one R₅₀, iii) a condensed ring in which at least two first rings unsubstituted or substituted with at least one R₅₀are condensed, iv) a condensed ring in which at least two second rings unsubstituted or substituted with at least one R₅₀are condensed, or v) a condensed ring in which at least one first ring and at least one second ring, each unsubstituted or substituted with at least one R₅₀, are condensed,

Ar₅and Ar₁₂in Formulae 5 and 7 may each independently be a single bond, or a group derived from i) a first ring unsubstituted or substituted with at least one R_50a, ii) a second ring unsubstituted or substituted with at least one R_50a, iii) a condensed ring in which at least two first rings unsubstituted or substituted with at least one R_50aare condensed, iv) a condensed ring in which at least two second rings unsubstituted or substituted with at least one R_50aare condensed, or v) a condensed ring in which at least one first ring and at least one second ring, each unsubstituted or substituted with at least one R_50a, are condensed, or Ar₅and Ar₁₂may not be present,

ring CY₅₁and ring CY₅₂in Formula 5 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, iv) a condensed ring in which at least two second rings are condensed, or v) a condensed ring in which at least one first ring and at least one second ring are condensed,

Het1 in Formula 7 may be i) a first ring, ii) a condensed ring in which at least two first rings are condensed, or iii) a condensed ring in which at least one first ring and at least one second ring are condensed, the first ring may be an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyridazine group, a pyrimidine group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, or a thiadiazole group, and the second ring may be a benzene group, a cyclopentadiene group, a pyrrole group, a furan group, a thiophene group, or a silole group.

In one or more embodiments, in Formulae 5 and 7, Ar₁, Ar₂, and Ar₁₁may each independently be a benzene group, a heptalene group, an indene group, a naphthalene group, an azulene group, an indacene group, an acenaphthylene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentacene group, a hexacene group, a pentaphene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a furan group, a thiophene group, an isoindole group, an indole group, an indene group, a benzofuran group, a benzothiophene group, a benzosilole group, a naphthopyrrole group, a naphthofuran group, a naphthothiophene group, a naphthosilole group, a benzocarbazole group, a dibenzocarbazole group, a dibenzofuran group, a dibenzothiophene group, a dibenzothiophene sulfone group, a carbazole group, a dibenzosilole group, an indenocarbazole group, an indolocarbazole group, a benzofurocarbazole group, a benzothienocarbazole group, a benzosilolocarbazole group, a triindolobenzene group, an acridine group, dihydroacridine group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyridazine group, a pyrimidine group, an indazole group, a purine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a phthalazine group, a naphthyridine group, a quinoxaline group, a benzoquinoxaline group, a quinazoline group, a cinnoline group, a phenanthridine group, an acridine group, a phenanthroline group, a phenazine group, a benzimidazole group, an isobenzothiazole group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a thiadiazole group, an imidazopyridine group, an imidazopyrimidine group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, an azadibenzosilole group, a benzonaphthofuran group, a benzonapthothiophene group, an (indolo)phenanthrene group, a (benzofurano)phenanthrene group, or a (benzothieno)phenanthrene group.

In one or more embodiments, in Formulae 5 and 7, Ar₅and Ar₁₂may each independently be a single bond, or a benzene group, a naphthalene group, or a carbazole group, each unsubstituted or substituted with at least one R_50a, or Ar₅and Ar₁₂may not be present.

In one or more embodiments, in Formula 5, ring CY₅₁and ring CY₅₂may each independently be a benzene group, a heptalene group, an indene group, a naphthalene group, an azulene group, an indacene group, acenaphthylene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentacene group, a hexacene group, a pentaphene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a furan group, a thiophene group, an isoindole group, an indole group, an indene group, a benzofuran group, a benzothiophene group, a benzosilole group, a naphthopyrrole group, a naphthofuran group, a naphthothiophene group, a naphthosilole group, a benzocarbazole group, a dibenzocarbazole group, a dibenzofuran group, a dibenzothiophene group, a dibenzothiophene sulfone group, a carbazole group, a dibenzosilole group, an indenocarbazole group, an indolocarbazole group, a benzofurocarbazole group, a benzothienocarbazole group, a benzosilolocarbazole group, a triindolobenzene group, an acridine group, dihydroacridine group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyridazine group, a pyrimidine group, an indazole group, a purine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a phthalazine group, a naphthyridine group, a quinoxaline group, a benzoquinoxaline group, a quinazoline group, a cinnoline group, a phenanthridine group, an acridine group, a phenanthroline group, a phenazine group, a benzimidazole group, an isobenzothiazole group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a thiadiazole group, an imidazopyridine group, an imidazopyrimidine group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, an azadibenzosilole group, a pyrrolophenanthrene group, a furanophenanthrene group, or a thienophenanthrene group.

In one or more embodiments, Het1 in Formula 7 may be an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyridazine group, a pyrimidine group, an indazole group, a purine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a phthalazine group, a naphthyridine group, a quinoxaline group, a benzoquinoxaline group, a quinazoline group, a cinnoline group, a phenanthridine group, an acridine group, a phenanthroline group, a phenazine group, a benzimidazole group, an isobenzothiazole group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a thiadiazole group, an imidazopyridine group, an imidazopyrimidine group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, an azadibenzosilole group, or a pyridopyrazine group.

In one or more embodiments, in Formulae 5 and 7, Ar₁, Ar₂, and Ar₁₁may each independently be a π electron-rich C₃-C₆₀cyclic group unsubstituted or substituted with at least one R₅₀.

In one or more embodiments, in Formulae 5 and 7, Ar₅and Ar₁₂may each independently be a single bond or a π electron-rich C₃-C₆₀cyclic group unsubstituted or substituted with at least one R_50a, or Ar₅and Ar₁₂may not be present.

In one or more embodiments, in Formula 5, ring CY₅₁and ring CY₅₂may each independently be a π electron-rich C₃-C₆₀cyclic group.

In one or more embodiments, in Formulae 5 and 7, n and p may each independently be 1 or 2.

In one or more embodiments, in Formula 5, n6 may be 1, and at least one of ring CY₅₁and CY₅₂may not be a benzene group.

In some embodiments, in Formula 5, when n6 is 1, at least one of ring CY₅₁and ring CY₅₂may be a) a condensed ring in which at least two first rings are condensed, b) a condensed ring in which at least two second rings are condensed, or c) a condensed ring in which at least one first ring and at least one second ring are condensed. The first ring and the second ring may respectively be understood by referring to the descriptions of the first ring and the second ring provided herein.

In one or more embodiments, the compound represented by Formula 5 may include a compound represented by Formula 5(1):

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wherein, in Formula 5(1),

Ar₅may be a single bond, a C₅-C₆₀carbocyclic group unsubstituted or substituted with at least one R_50a, or a C₁-C₆₀heterocyclic group unsubstituted or substituted with at least one R_50a,

Ar₁, Ar₂, Ar₅, a1, a2, ring CY₅₁, ring CY₅₂, R₅₁, R₅₂, b51, and b52 may respectively be understood by referring to the descriptions of Ar₁, Ar₂, Ar₅, a1, a2, ring CY₅₁, ring CY₅₂, R₅₁, R₅₂, b51, and b52 provided herein,

Ar₃and Ar₄may each independently be a C₅-C₆₀carbocyclic group unsubstituted or substituted with at least one R₅₀or a C₁-C₆₀heterocyclic group unsubstituted or substituted with at least one R₅₀, and

a3, a4, ring CY₅₃, ring CY₅₄, R₅₃, R₅₄, b53, and b54 may respectively be understood by referring to the descriptions of a1, a2, ring CY₅₁, ring CY₅₂, R₅₁, R₅₂, b51, and b52 provided herein.

For example, in Formula 5(1), Ar₅may be a single bond.

In one or more embodiments, the compound represented by Formula 7 may include a compound represented by Formula 7(1):

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wherein, in Formula 7(1),

Ar₁₂may be a single bond, a C₅-C₆₀carbocyclic group unsubstituted or substituted with at least one R_50a, or a C₁-C₆₀heterocyclic group unsubstituted or substituted with at least one R_50a,

Het1, Ar₁₁, R₇₀, R₈₀, a11, b7, b8, and m may respectively be understood by referring to the descriptions of Het1, Ar₁₁, R₇₀, R₈₀, a11, b7, b8, and m provided herein, and

Het3, Ar₁₃, R₇₃, R₈₃, a13, b73, b83, and m3 may respectively be understood by referring to the descriptions of Het1, Ar₁₁, R₇₀, R₈₀, a11, b7, b8, and m provided herein.

In one or more embodiments, the first electron-transporting compound and the second electron-transporting compound may each include a carbazole group, and the number of carbazole group(s) in the first electron-transporting compound may be greater than the number of carbazole group(s) in the second electron-transporting compound.

In one or more embodiments, the number of carbazole group(s) in the first electron-transporting compound may be 2 or greater.

In one or more embodiments, the number of carbazole group(s) in the second electron-transporting compound may be 0 or 1.

In one or more embodiments, the first electron-transporting compound may be a compound represented by Formula 7S, and the second electron-transporting compound may be a compound represented by Formula 7F:

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wherein, in Formulae 7S and 7F,

Ar₇₁to Ar₇₆may each be understood by referring to the description of Ar₁₁in Formula 7,

a71 to a76 may each be understood by referring to the description of a11 in Formula 7, and

R₇₁to R₇₆may each be understood by referring to the description of R₇₀in Formula 7.

In an embodiment, in Formulae 7S and 7F, Ar₇₁to Ar₇₆may each independently be a benzene group or a carbazole group, each unsubstituted or substituted with deuterium, a C₁-C₂₀alkyl group, a phenyl group, a deuterated phenyl group, a (C₁-C₂₀alkyl)phenyl group, a biphenyl group, a deuterated biphenyl group, a (C₁-C₂₀alkyl)biphenyl group, or any combination thereof.

In one or more embodiments, in Formulae 7S and 7F, a71 to a76 may each independently be 1, 2, or 3.

In one or more embodiments, in Formulae 7S and 7F, R₇₁to R₇₆may each independently be hydrogen, deuterium, a C₁-C₂₀alkyl group, a phenyl group, a deuterated phenyl group, a (C₁-C₂₀alkyl)phenyl group, a biphenyl group, a deuterated biphenyl group, a (C₁-C₂₀alkyl)biphenyl group, a carbazolyl group, a deuterated carbazolyl group, a (C₁-C₂₀alkyl)carbazolyl group, a di(C₁-C₂₀alkyl)carbazolyl group, or a (phenyl)carbazolyl group.

In one or more embodiments, the number of carbazole group(s) in the compound represented by Formula 7S may be 2 or greater.

In one or more embodiments, the number of carbazole group(s) in the compound represented by Formula 7F may be 0 or 1.

In one or more embodiments, in Formula 7S,

Ar₇₃may be a benzene group unsubstituted or substituted with deuterium, a C₁-C₂₀alkyl group, a phenyl group, a deuterated phenyl group, a (C₁-C₂₀alkyl)phenyl group, a biphenyl group, a deuterated biphenyl group, a (C₁-C₂₀alkyl)biphenyl group, or any combination thereof, and

R₇₃may be hydrogen, deuterium, a C₁-C₂₀alkyl group, a phenyl group, a deuterated phenyl group, a (C₁-C₂₀alkyl)phenyl group, a biphenyl group, a deuterated biphenyl group, or a (C₁-C₂₀alkyl)biphenyl group.

In one or more embodiments, in Formula 7F,

Ar₇₄and Ar₇₅may each independently be a benzene group unsubstituted or substituted with deuterium, a C₁-C₂₀alkyl group, a phenyl group, a deuterated phenyl group, a (C₁-C₂₀alkyl)phenyl group, a biphenyl group, a deuterated biphenyl group, a (C₁-C₂₀alkyl)biphenyl group, or any combination thereof, and

R₇₄and R₇₆may each independently be R₇₄may be hydrogen, deuterium, a C₁-C₂₀alkyl group, a phenyl group, a deuterated phenyl group, a (C₁-C₂₀alkyl)phenyl group, a biphenyl group, a deuterated biphenyl group, or a (C₁-C₂₀alkyl)biphenyl group.

In one or more embodiments, a group represented by

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in Formula 5, a group represented by

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in Formula 5(1), and a group represented by

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in Formula 5(1) may each independently be a group represented by one of Formulae 2-1 to 2-93:

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wherein, in Formulae 2-1 to 2-93,

X₅₁may be O, S, N(R_51a), C(R_51a)(R_51b), or Si(R_51a)(R_51b),

X₅₂may be O, S, N(R_52a), C(R_52a)(R_52b), or Si(R_52a)(R_52b),

R_51a, R_51b, R_52a, and R_52bmay each be understood by referring to the descriptions of R₅₁provided herein, and

* indicates a binding site to Ar₁or Ar₃.

In one or more embodiments, Het1 in Formula 7 and Het1 and Het3 in Formula 7(1) may each independently be a group derived from one of Formulae 3-1 to 3-40:

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In Formulae 5 and 5(1), a1 and a2 respectively indicate the number of Ar₁(s) and Ar₂(s). a1 and a2 may each independently be an integer from 0 to 5 (e.g., 0, 1, or 2), and the sum of a1 and a2 may be 1 or greater. When a1 is two or greater, at least two Ar₁(s) may be identical to or different from each other, and when a2 is two or greater, at least two Ar₂(s) may be identical to or different from each other. When a1 is 0, *—(Ar₁)_a1—*′ in in Formula 2 may be a single bond.

In Formulae 7 and 7(1), a11 and m may respectively indicate the number of Ar₁₁(s) and *—(Ar₁₁)_a11—(R₇₀)_a70(s). a11 and m may each independently be an integer from 1 to 10. When a11 is 2 or greater, at least two Ar₁₁(s) may be identical to or different from each other. When m is 2 or greater, at least two *—(Ar₁₁)_a11—(R₇₀)_a70(s) may be identical to or different from each other.

In an embodiment, in Formulae 7 and 7(1), a11 and m may each independently be an integer from 1 to 3.

R₅₀to R₅₄, R_50ato R_50d, R_51a, R_51b, R_52a, R_52b, R₇₀, R₇₃, R₈₀, and R₈₃may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, —SF₅, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C₁-C₆₀alkyl group, a substituted or unsubstituted C₂-C₆₀alkenyl group, a substituted or unsubstituted C₂-C₆₀alkynyl group, a substituted or unsubstituted C₁-C₆₀alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀arylthio group, a substituted or unsubstituted C₁-C₆₀heteroaryl 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), —Ge(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), —P(═O)(Q₈)(Q₉), or —P(Q₈)(Q₉). Q₁to Q₉may respectively be understood by referring to the descriptions of Q₁to Q₉provided herein.

For example, R₅₀to R₅₄, R_50ato R_50d, R_51a, R_51b, R_52a, R_52b, R₇₀, R₇₃, R₈₀, and R₈₃may each independently be:

a C₁-C₂₀alkyl group or a C₁-C₂₀alkoxy group, each substituted with deuterium, —F, —Cl, —Br, —I, —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-C₂₀alkyl group, a deuterium-containing C₁-C₂₀alkyl group, a fluorinated C₁-C₂₀alkyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl group, a bicyclo[2.2.1]heptyl group (norbornanyl group), a bicyclo[2.2.2]octyl group, a (C₁-C₂₀alkyl)cyclopentyl group, a (C₁-C₂₀alkyl)cyclohexyl group, a (C₁-C₂₀alkyl)cycloheptyl group, a (C₁-C₂₀alkyl)cyclooctyl group, a (C₁-C₂₀alkyl)adamantanyl group, a (C₁-C₂₀alkyl)norbornenyl group, a (C₁-C₂₀alkyl)cyclopentenyl group, a (C₁-C₂₀alkyl)cyclohexenyl group, a (C₁-C₂₀alkyl)cycloheptenyl group, a (C₁-C₂₀alkyl)bicyclo[1.1.1]pentyl group, a (C₁-C₂₀alkyl)bicyclo[2.1.1]hexyl group, a (C₁-C₂₀alkyl)bicyclo[2.2.1]heptyl group, a (C₁-C₂₀alkyl)bicyclo[2.2.2]octyl group, a silolanyl group, a phenyl group, a (C₁-C₂₀alkyl)phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a 1,2,3,4-tetrahydronaphthyl group, a pyridinyl group, a pyrimidinyl group, or any combination thereof;

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl group, a bicyclo[2.2.1]heptyl group, a bicyclo[2.2.2]octyl group, a silolanyl group, a phenyl group, a (C₁-C₂₀alkyl)phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a 1,2,3,4-tetrahydronaphthyl 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 purinyl 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 benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzoisothiazolyl 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 benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolyl group, an azadibenzofuranyl group, or an azadibenzothiophenyl group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, —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-C₂₀alkyl group, a deuterium-containing C₁-C₂₀alkyl group, a fluorinated C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl group, a bicyclo[2.2.1]heptyl group, a bicyclo[2.2.2]octyl group, a (C₁-C₂₀alkyl)cyclopentyl group, a (C₁-C₂₀alkyl)cyclohexyl group, a (C₁-C₂₀alkyl)cycloheptyl group, a (C₁-C₂₀alkyl)cyclooctyl group, a (C₁-C₂₀alkyl)adamantanyl group, a (C₁-C₂₀alkyl)norbornenyl group, a (C₁-C₂₀alkyl)cyclopentenyl group, a (C₁-C₂₀alkyl)cyclohexenyl group, a (C₁-C₂₀alkyl)cycloheptenyl group, a (C₁-C₂₀alkyl)bicyclo[1.1.1]pentyl group, a (C₁-C₂₀alkyl)bicyclo[2.1.1]hexyl group, a (C₁-C₂₀alkyl)bicyclo[2.2.1]heptyl group, a (C₁-C₂₀alkyl)bicyclo[2.2.2]octyl group, a silolanyl group, a phenyl group, a (C₁-C₂₀alkyl)phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a 1,2,3,4-tetrahydronaphthyl 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 purinyl 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 benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzoisothiazolyl 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 benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, or any combination thereof; or

—N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —Ge(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), —P(═O)(Q₈)(Q₉), or —P(Q₈)(Q₉),

wherein Q₁to Q₉may each independently be:

—CH₃, —CD₃, —CD₂H, —CDH₂, —CH₂CH₃, —CH₂CD₃, —CH₂CD₂H, —CH₂CDH₂, —CHDCH₃, —CHDCD₂H, —CHDCDH₂, —CHDCD₃, —CD₂CD₃, —CD₂CD₂H, or —CD₂CDH₂, or

an n-propyl group, an iso-propyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a tert-pentyl group, a neopentyl group, an isopentyl group, a sec-pentyl group, a 3-pentyl group, a sec-isopentyl group, a phenyl group, a biphenyl group, or a naphthyl group, each unsubstituted or substituted with deuterium, a C₁-C₂₀alkyl group, a phenyl group, or any combination thereof.

b51 to b54, b7, b73, b8, and b83 may respectively indicate the number of R₅₀(s) to R₅₄(s), R₇₀(s), R₇₃(s), R₈₀(s), and R₈₃(s), and b51 to b54, b7, b73, b8, and b83 may each independently be an integer from 0 to 20. For example, b51 to b54, b7, b73, b8, and b83 may each independently be an integer from 0 to 10. When b51 is 2 or greater, at least two R₅₁(s) may be identical to or different from each other. When b52 is 2 or greater, at least two R₅₂(s) may be identical to or different from each other. When b53 is 2 or greater, at least two R₅₃(s) may be identical to or different from each other. When b54 is 2 or greater, at least two R₅₄(s) may be identical to or different from each other. When b7 is 2 or greater, at least two R₇₀(s) may be identical to or different from each other. When b73 is 2 or greater, at least two R₇₃(s) may be identical to or different from each other. When b8 is 2 or greater, at least two R₈₀(s) may be identical to or different from each other. When b83 is 2 or greater, at least two R₈₃(s) may be identical to or different from each other.

For example, R₅₀to R₅₄, R_50ato R₅₀d, R_51a, R_51b, R_52a, R_52b, R₇₀, R₇₃, R₈₀, and R₈₃may each independently be:

hydrogen or deuterium;

a C₁-C₂₀alkyl group or a C₁-C₂₀alkoxy group, each unsubstituted or substituted with deuterium, a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a triphenylenyl group, a fluorenyl group, a di(C₁-C₁₀alkyl)fluorenyl group, a di(C₆-C₆₀aryl)fluorenyl group, a dibenzosilolyl group, a di(C₁-C₁₀alkyl)dibenzosilolyl group, a di(C₆-C₆₀aryl)dibenzosilolyl group, a carbazolyl group, a (C₁-C₁₀alkyl)carbazolyl group, a (C₆-C₆₀aryl)carbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a biphenyl group, a terphenyl group, —N(Q₃₁)(Q₃₂), or any combination thereof;

a π electron-rich C₃-C₆₀cyclic group, unsubstituted or substituted with deuterium, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a triphenylenyl group, a fluorenyl group, a di(C₁-C₁₀alkyl)fluorenyl group, a di(C₆-C₆₀aryl)fluorenyl group, a dibenzosilolyl group, a di(C₁-C₁₀alkyl)dibenzosilolyl group, a di(C₆-C₆₀aryl)dibenzosilolyl group, a carbazolyl group, a (C₁-C₁₀alkyl)carbazolyl group, a (C₆-C₆₀aryl)carbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a biphenyl group, a terphenyl group, —N(Q₃₁)(Q₃₂), or any combination thereof; or —N(Q₁)(Q₂).

Q₁, Q₂, Q₃₁, and Q₃₂may respectively be understood by referring to the descriptions of Q₁, Q₂, Q₃₁, and Q₃₂provided herein.

In some embodiments, R₅₀to R₅₄, R_50ato R₅₀d, R_51a, R_51b, R_52a, R_52b, R₇₀, R₇₃, R₈₀, and R₈₃may each independently be:

hydrogen or deuterium;

a C₁-C₂₀alkyl group unsubstituted or substituted with deuterium, a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a triphenylenyl group, a fluorenyl group, a di(C₁-C₁₀alkyl)fluorenyl group, a di(C₆-C₆₀aryl)fluorenyl group, a dibenzosilolyl group, a di(C₁-C₁₀alkyl)dibenzosilolyl group, a di(C₆-C₆₀aryl)dibenzosilolyl group, a carbazolyl group, a (C₁-C₁₀alkyl)carbazolyl group, a (C₆-C₆₀aryl)carbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a biphenyl group, a terphenyl group, —N(Q₃₁)(Q₃₂), or any combination thereof; or a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a triphenylenyl group, a fluorenyl group, a dibenzosilolyl group, a carbazolyl group, a dibenzofuranyl group, or a dibenzothiophenyl group, each unsubstituted or substituted with deuterium, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a triphenylenyl group, a fluorenyl group, a di(C₁-C₁₀alkyl)fluorenyl group, a di(C₆-C₆₀aryl)fluorenyl group, a dibenzosilolyl group, a di(C₁-C₁₀alkyl)dibenzosilolyl group, a di(C₆-C₆₀aryl)dibenzosilolyl group, a carbazolyl group, a (C₁-C₁₀alkyl)carbazolyl group, a (C₆-C₆₀aryl)carbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a biphenyl group, a terphenyl group, or any combination thereof.

Q₃₁and Q₃₂may respectively be understood by referring to the descriptions of Q₃₁and Q₃₂provided herein.

In Formulae 5 and 7, 1) at least two R₅₁(s) may optionally be bound to form a C₅-C₆₀carbocyclic group unsubstituted or substituted with at least one R_10aor a C₁-C₆₀heterocyclic group unsubstituted or substituted with at least one R_10a, 2) at least two R₅₂(s) may optionally be bound to from a C₅-C₆₀carbocyclic group unsubstituted or substituted with at least one R_10aor a C₁-C₆₀heterocyclic group unsubstituted or substituted with at least one R_10a, and 3) at least two of ring CY₅₁, ring CY₅₂, R₅₁, and R₅₂may optionally be bound to form a C₅-C₆₀carbocyclic group unsubstituted or substituted with at least one R_10aor a C₁-C₆₀heterocyclic group unsubstituted or substituted with at least one R_10a. R_10amay be understood by referring to the description of R₁provided herein.

Descriptions of Compounds

In an embodiment, the first dopant and the second dopant may each be one of compounds of Group 1-1 to Group 1-7:

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wherein “OMe” in Compounds 1 to 1621 in Group 1-1 represents a methoxy group.

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In one or more embodiments, the first hole-transporting compound and the second hole-transporting compound may each independently be at least one of Compounds H1-1 to H1-72 of Group 5-1 and Compounds H1-1 to H1-20 of Group 5-2:

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In one or more embodiments, the first electron-transporting compound and the second electron-transporting compound may each be at least one of Compounds E1-1 to E1-63:

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Description of FIG. 2

FIG. 2 is a schematic view of an exemplary embodiment of a light-emitting device, an organic light-emitting device 10. Hereinafter, a structure and a method of manufacturing the organic light-emitting device according to an embodiment will be described with reference to FIG. 2.

The organic light-emitting device 10 in FIG. 2 may include a first electrode 11, a hole transport region 13, an emission layer 15, an electron transport region 17, and a second electrode 19, which are sequentially layered in the stated order. The emission layer 15 may include the first emission layer 15-1 and the second emission layer 15-2.

A substrate may be additionally disposed under the first electrode 11 or on the second electrode 19. The substrate may be a conventional substrate used in organic light-emitting devices, e.g., a glass substrate or a transparent plastic substrate, each having excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and water repellency.

The first electrode 11 may be produced by depositing or sputtering, onto the substrate, a material for forming the first electrode 11. The first electrode 11 may be an anode. The material for forming the first electrode 11 may be selected from materials with a high work function for easy hole injection. The first electrode 11 may be a reflective electrode, a semi-transmissive electrode, or a transmissive electrode. 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 some 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. In some embodiments, the first electrode 11 may have a triple-layered structure of ITO/Ag/ITO, but embodiments are not limited thereto.

The hole transport region 13 may be between the first electrode 11 and the emission layer 15.

The hole transport region 13 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 13 may include a hole injection layer only or a hole transport layer only. In some embodiments, the hole transport region 13 may include a hole injection layer and a hole transport layer which are sequentially stacked on the first electrode 11. In some embodiments, the hole transport region may include a hole injection layer, a hole transport layer, and an electron blocking layer, which are sequentially stacked on the first electrode 11.

When the hole transport region 13 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 a hole injection layer is formed by vacuum-deposition, for example, the vacuum deposition may be performed at a temperature in a range of about 100° C. to about 500° C., at a vacuum pressure in a range of about 10⁻⁸torr to about 10⁻³torr, and at a rate in a range of about 0.01 Angstroms per second (A/sec) to about 100 Å/sec, though the conditions may vary depending on a compound used as a hole injection material and a structure and thermal properties of a desired hole injection layer.

When a hole injection layer is formed by spin coating, the spin coating may be performed at a rate in a range of about 2,000 revolutions per minute (rpm) to about 5,000 rpm and at a temperature in a range of about 80° C. to 200° C. to facilitate removal of a solvent after the spin coating, though the conditions may vary depending on a compound used as a hole injection material and a structure and thermal properties of a desired hole injection layer, but embodiments are not limited thereto.

The conditions for forming a hole transport layer and an electron blocking layer may be inferred from the conditions for forming the hole injection layer.

The hole transport region 13 may include m-MTDATA, TDATA, 2-TNATA, NPB, β-NPB, TPD, spiro-TPD, spiro-NPB, methylated-NPB, TAPC, 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-styrene sulfonate) (PANI/PSS), a compound represented by Formula 201, a compound represented by Formula 202, or any combination thereof:

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wherein, in Formula 201, Ar₁₀₁and Ar₁₀₂may 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 deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀alkynyl group, a C₁-C₆₀alkoxy group, a C₃-C₁₀cycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀heterocycloalkyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, or any combination thereof.

In Formula 201, xa and xb may each independently be an integer from 0 to 5. In some embodiments, xa and xb may each independently be 0, 1, or 2. In some embodiments, xa may be 1, and xb may be 0, but embodiments are not limited thereto.

In Formulae 201 and 202, R₁₀₁to R₁₀₈, R₁₁₁to R₁₁₉, and R₁₂₁to R₁₂₄may each independently be:

hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₁₀alkyl group (e.g., a methyl group, an ethyl group, a propyl group, a butyl group, pentyl group, or a hexyl group), or a C₁-C₁₀alkoxy group (e.g., a methoxy group, an ethoxy group, a propoxy group, a butoxy group, or a pentoxy group);

a C₁-C₁₀alkyl group or a C₁-C₁₀alkoxy group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, or any combination thereof; or a phenyl group, a naphthyl group, an anthracenyl group, a fluorenyl group, or a pyrenyl group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₁₀alkyl group, a C₁-C₁₀alkoxy group, or any combination thereof.

In Formula 201, R₁₀₉may be a phenyl group, a naphthyl group, an anthracenyl group, or a pyridinyl group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₂₀alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a naphthyl group, an anthracenyl group, a pyridinyl group, or any combination thereof.

In some embodiments, the compound represented by Formula 201 may be represented by Formula 201A:

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wherein, in Formula 201A, R₁₀₁, R₁₁₁, R₁₁₂, and R₁₀₉may respectively be understood by referring to the descriptions of R₁₀₁, R₁₁₁, R₁₁₂, and R₁₀₉provided herein.

In some embodiments, the hole transport region 13 may include one of Compounds HT1 to HT20 or any combination thereof:

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The thickness of the hole transport region 13 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 13 includes a hole injection layer, a hole transport layer, an electron blocking layer, or any combination thereof, the 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, the 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 any of these ranges, excellent hole transport characteristics may be obtained without a substantial increase in driving voltage.

The hole transport region 13 may include a charge generating material as well as the aforementioned materials, to improve conductive properties of the hole transport region. The charge generating material may be substantially homogeneously or non-homogeneously dispersed in the hole transport region.

The charge generating material may include, for example, a p-dopant. The p-dopant may be a quinone derivative, a metal oxide, a compound containing a cyano group, or any combination thereof, but embodiments are not limited thereto. In some embodiments, the p-dopant may be a quinone derivative, such as tetracyanoquinodimethane (TCNQ), a 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; a compound containing a cyano group, such as Compound HT-D1; or any combination thereof:

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The hole transport region 13 may further include a buffer layer.

The buffer layer may compensate for an optical resonance distance depending on a wavelength of light emitted from the emission layer to improve the efficiency of an organic light-emitting device.

When the hole transport region 13 includes an electron blocking layer, a material for forming the electron blocking layer may include the material for forming a hole transport region 13, the material for forming a host, or any combination thereof. In some embodiments, when the hole transport region includes an electron blocking layer, mCP, Compound H1-8 of Group 5-2, or the like may be used for forming the electron blocking layer.

The emission layer 15 may be formed on the hole transport region 13 by using one or more suitable methods, such as vacuum deposition, spin coating, casting, or LB deposition. When the emission layer 15 is formed by vacuum deposition or spin coating, vacuum deposition and coating conditions for forming the emission layer may be generally similar to those conditions for forming a hole injection layer, though the conditions may vary depending on a compound that is used.

The emission layer 15 may include the first emission layer 15-1 and the second emission layer 15-2 as described herein.

In some embodiments, the content (weight) of the dopant in the first emission layer 15-1 may be in a range of about 0.01 parts to about 20 parts by weight, based on 100 parts by weight of the total weight of the first hole-transporting compound and the first electron-transporting compound.

In some embodiments, the content (weight) of the dopant in the first emission layer 15-1 may be in a range of about 0.01 parts to about 20 parts by weight, based on 100 parts by weight of the total weight of the dopant, the first hole-transporting compound and the first electron-transporting compound.

In some embodiments, the content (weight) of the dopant in the second emission layer 15-2 may be in a range of about 0.01 parts to about 20 parts by weight, based on 100 parts by weight of the total weight of the second hole-transporting compound and the second electron-transporting compound.

In some embodiments, the content (weight) of the dopant in the second emission layer 15-2 may be in a range of about 0.01 parts to about 20 parts by weight, based on 100 parts by weight of the total weight of the dopant, the second hole-transporting compound and the second electron-transporting compound.

The thickness of the emission layer 15 may be in a range of about 100 Å to about 1,000 Å, and in some embodiments, about 200 Å to about 600 Å. When the thickness of the emission layer 15 is within any of these ranges, improved luminescence characteristics may be obtained without a substantial increase in driving voltage.

Then, the electron transport region 17 may be over the emission layer 15.

The electron transport region 17 may include a hole blocking layer, an electron transport layer, an electron injection layer, or a combination thereof.

In some embodiments, the electron transport region 17 may have a hole blocking layer/an electron transport layer/an electron injection layer structure or an electron transport layer/an electron injection layer structure. The electron transport layer may have a single-layered structure or a multi-layered structure including two or more different materials.

The conditions for forming a hole blocking layer, an electron transport layer, and an electron injection layer of the electron transport region 17 may be understood by referring to the conditions for forming the hole injection layer.

When the electron transport region 17 includes a hole blocking layer, the hole blocking layer may include, for example, BCP, Bphen, BAlq, or any combination thereof:

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In some embodiments, the hole blocking layer may include any suitable host material, the material for forming an electron transport layer described herein, the material for forming an electron injection layer described herein, or any combination thereof.

The thickness of the hole blocking layer may be in a range of about 20 Å to about 1,000 Å, for example, about 300 Å to about 300 Å. When the thickness of the hole blocking layer is within any of these ranges, excellent hole blocking characteristics may be obtained without a substantial increase in driving voltage.

The electron transport layer may include BCP, Bphen, TPBi, Alq₃, BAlq, TAZ, NTAZ, or any combination thereof:

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In some embodiments, the electron transport layer may include at least one of Compounds ET1 to ET25.

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The thickness of the electron transport layer may be in a range of about 100 Å to about 1,000 Å, and in some embodiments, about 150 Å to about 500 Å. When the thickness of the electron transport layer is within any of these ranges, excellent electron transport characteristics may be obtained without a substantial increase in driving voltage.

The electron transport layer may further include a material containing metal, in addition to the materials described above.

The material containing metal may include a L₁complex. The L₁complex may include, e.g., Compound ET-D1 or Compound ET-D2:

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The electron transport region 17 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 any combination thereof.

The thickness of the electron injection layer may be in a range of about 1 Å to about 100 Å, and in some embodiments, about 3 Å to about 90 Å. When the thickness of the electron injection layer is within any of these ranges, excellent electron injection characteristics may be obtained without a substantial increase in driving voltage.

The second electrode 19 may be on the electron transport region 17. The second electrode 19 may be a cathode. A material for forming the second electrode 19 may be a material with a relatively low work function, such as a metal, an alloy, an electrically conductive compound, and a mixture thereof. Examples of the material for forming the second electrode 19 may include lithium (Li), magnesium (Mg), aluminum (Al), silver (Ag), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), and magnesium-silver (Mg—Ag). In some embodiments, ITO or IZO may be used to form a transmissive second electrode 19 to manufacture a top emission light-emitting device. In some embodiments, the material for forming the second electrode 19 may vary.

Hereinbefore the organic light-emitting device has been described with reference to FIG. 2, but embodiments are not limited thereto.

According to an aspect of another embodiment, an electronic apparatus may include the light-emitting device. Thus, an electronic apparatus including the light-emitting device may be provided. The electronic apparatus may include, for example, a display, lighting, a sensor, or the like.

The term “C₁-C₆₀alkyl group” as used herein refers to a linear or branched saturated aliphatic hydrocarbon monovalent group having 1 to 60 carbon atoms, and the term “C₁-C₆₀alkylene group” as used herein refers to a divalent group having the same structure as the C₁-C₆₀alkyl group.

Examples of the C₁-C₆₀alkyl group, the C₁-C₂₀alkyl group, and/or the C₁-C₁₀alkyl group as used herein may include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a tert-pentyl group, a neopentyl group, an isopentyl group, a sec-pentyl group, a 3-pentyl group, a sec-isopentyl group, an n-hexyl group, an iso-hexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an iso-heptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an iso-octyl group, a sec-octyl group, a tert-octyl group, an n-nonyl group, an iso-nonyl group, a sec-nonyl group, a tert-nonyl group, an n-decyl group, an iso-decyl group, a sec-decyl group, or a tert-decyl group, each unsubstituted or substituted with a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a tert-pentyl group, a neopentyl group, an isopentyl group, a sec-pentyl group, a 3-pentyl group, a sec-isopentyl group, an n-hexyl group, an iso-hexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an iso-heptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an iso-octyl group, a sec-octyl group, a tert-octyl group, an n-nonyl group, an iso-nonyl group, a sec-nonyl group, a tert-nonyl group, an n-decyl group, an iso-decyl group, a sec-decyl group, a tert-decyl group, or any combination thereof. In some embodiments, Formula 9-33 may be a branched C₆alkyl group. Formula 9-33 may be a tert-butyl group substituted with two methyl groups.

The term “C₁-C₆₀alkoxy group” as used herein refers to a monovalent group represented by —OA₁₀₁(wherein A₁₀₁is a C₁-C₆₀alkyl group). Examples thereof include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and a pentoxy group.

The term “C₂-C₆₀alkenyl group” as used herein refers to a group formed by placing at least one carbon-carbon double bond in the middle or at the terminus of the C₂-C₆₀alkyl group. Examples thereof include an ethenyl group, a propenyl group, and a butenyl group. The term “C₂-C₆₀alkenylene group” as used herein refers to a divalent group having the same structure as the C₂-C₆₀alkenyl group.

The term “C₂-C₆₀alkynyl group” as used herein refers to a group formed by placing at least one carbon-carbon triple bond in the middle or at the terminus of the C₂-C₆₀alkyl group. Examples thereof include an ethynyl group and a propynyl group. The term “C₂-C₆₀alkynylene group” as used herein refers to a divalent group having the same structure as the C₂-C₆₀alkynyl group.

The term “C₃-C₁₀cycloalkyl group” as used herein refers to a monovalent saturated hydrocarbon cyclic group having 3 to 10 carbon atoms. The term “C₃-C₁₀cycloalkylene group” as used herein refers to a divalent group having the same structure as the C₃-C₁₀cycloalkyl group.

Examples of the C₃-C₁₀cycloalkyl group as used herein include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl (bicyclo[2.2.1]heptyl) group, a bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl group, and a bicyclo[2.2.2]octyl group.

The term “C₁-C₁₀heterocycloalkyl group” as used herein refers to a monovalent cyclic group having 1 to 10 carbon atoms and at least one heteroatom of N, O, P, Si, S, Se, Ge, and B as a ring-forming atom. The term “C₁-C₁₀heterocycloalkylene group” as used herein refers to a divalent group having the same structure as the C₁-C₁₀heterocycloalkyl group.

Examples of the C₁-C₁₀heterocycloalkyl group as used herein may include a silolanyl group, a silinanyl group, a tetrahydrofuranyl group, a tetrahydro-2H-pyranyl group, or a tetrahydrothiophenyl group.

The term “C₃-C₁₀cycloalkenyl group” as used herein refers to a monovalent cyclic group that has 3 to 10 carbon atoms and at least one carbon-carbon double bond in its ring, and is not aromatic. Examples thereof include a cyclopentenyl group, a cyclohexenyl group, and a cycloheptenyl group. The term “C₃-C₁₀cycloalkenylene group” as used herein refers to a divalent group having the same structure as the C₃-C₁₀cycloalkenyl group.

The term “C₁-C₁₀heterocycloalkenyl group” as used herein refers to a monovalent cyclic group including at least one heteroatom of N, O, P, Si, S, Se, Ge, and B as a ring-forming atom, 1 to 10 carbon atoms, and at least one double bond in its ring. Examples of the C₁-C₁₀heterocycloalkenyl group include a 2,3-dihydrofuranyl group and a 2,3-dihydrothiophenyl group. The term “C₁-C₁₀heterocycloalkenylene group” as used herein refers to a divalent group having the same structure as the C₁-C₁₀heterocycloalkenyl group.

The term “C₆-C₆₀aryl group” as used herein refers to a monovalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms. The term “C₆-C₆₀arylene group” as used herein refers to a divalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms. Examples of the C₆-C₆₀aryl group include a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, and a chrysenyl group. When the C₆-C₆₀aryl group and the C₆-C₆₀arylene group each include a plurality of rings, the plurality of rings may be fused to each other.

The term “C₇-C₆₀alkyl aryl group” as used herein refers to a C₆-C₆₀aryl group substituted with at least one C₁-C₆₀alkyl group.

The term “C₁-C₆₀heteroaryl group” as used herein refers to a monovalent group having a heterocyclic aromatic system having at least one heteroatom of N, O, P, Si, S, Se, Ge, and B as a ring-forming atom and 1 to 60 carbon atoms. The term “C₁-C₆₀heteroarylene group” as used herein refers to a divalent group having a heterocyclic aromatic system having at least one heteroatom of N, O, P, Si, S, Se, Ge and B as a ring-forming atom and 1 to 60 carbon atoms. Examples of the C₁-C₆₀heteroaryl group include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, and an isoquinolinyl group. When the C₁-C₆₀heteroaryl group and the C₁-C₆₀heteroarylene group each include a plurality of rings, the plurality of rings may be fused to each other.

The term “C₂-C₆₀alkyl heteroaryl group” as used herein refers to a C₁-C₆₀heteroaryl group substituted with at least one C₁-C₆₀alkyl group.

The term “C₆-C₆₀aryloxy group” as used herein is represented by —OA₁₀₂(wherein A₁₀₂is the C₆-C₆₀aryl group). The term “C₆-C₆₀arylthio group” as used herein is represented by —SA₁₀₃(wherein A₁₀₃is the C₆-C₆₀aryl group). The term “C₁-C₆₀alkylthio group” as used herein is represented by —SA₁₀₄(wherein A₁₀₄is the C₁-C₆₀alkyl group).

The term “monovalent non-aromatic condensed polycyclic group” as used herein refers to a monovalent group that has two or more condensed rings and only carbon atoms (e.g., the number of carbon atoms may be in a range of 8 to 60) as ring-forming atoms, wherein the molecular structure as a whole is non-aromatic. 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 substantially the same structure as the monovalent non-aromatic condensed polycyclic group.

The term “monovalent non-aromatic condensed heteropolycyclic group” as used herein refers to a monovalent group that has two or more condensed rings and at least one heteroatom selected from N, O, P, Si, S, Se, Ge, and B and carbon atoms (e.g., the number of carbon atoms may be in a range of 1 to 60) as ring-forming atoms, wherein the molecular structure as a whole is non-aromatic. 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 substantially the same structure as the monovalent non-aromatic condensed heteropolycyclic group.

The term “C₅-C₃₀carbocyclic 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-C₃₀carbocyclic group may be a monocyclic group or a polycyclic group. Examples of the “C₅-C₃₀carbocyclic group (unsubstituted or substituted with at least one R_10a)” may include an adamantane group, a norbornene group, a bicyclo[1.1.1]pentane group, a bicyclo[2.1.1]hexane group, a bicyclo[2.2.1]heptane group (a norbornane group), a bicyclo[2.2.2]octane group, a cyclopentane group, a cyclohexane group, a cyclohexene group, a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a 1,2,3,4-tetrahydronaphthalene group, a cyclopentadiene group, or a fluorene group, (each unsubstituted or substituted with at least one R_10a).

The term “C₁-C₃₀heterocyclic group” as used herein refers to saturated or unsaturated cyclic group including 1 to 30 carbon atoms and at least one heteroatom selected from N, O, P, Si, S, Se, Ge, and B as ring-forming atoms. The C₁-C₃₀heterocyclic group may be a monocyclic group or a polycyclic group. Examples of the “C₁-C₃₀heterocyclic group (unsubstituted or substituted with at least one R_10a)” may include a thiophene group, a furan group, a pyrrole group, a silole group, a borole group, a phosphole group, a selenophene group, a germole group, a benzothiophene group, a benzofuran group, an indole group, a benzosilole group, a benzoborole group, a benzophosphole group, a benzoselenophene group, a benzogermole group, a dibenzothiophene group, a dibenzofuran group, a carbazole group, a dibenzosilole group, a dibenzoborole group, a dibenzophosphole group, a dibenzoselenophene group, a dibenzogermole group, a dibenzothiophene 5-oxide group, a 9H-fluorene-9-one group, a dibenzothiophene 5,5-dioxide group, an azabenzothiophene group, an azabenzofuran group, an azaindole group, an azaindene group, an azabenzosilole group, an azabenzoborole group, an azabenzophosphole group, an azabenzoselenophene group, an azabenzogermole group, an azadibenzothiophene group, an azadibenzofuran group, an azacarbazole group, an azafluorene group, an azadibenzosilole group, an azadibenzoborole group, an azadibenzophosphole group, an azadibenzoselenophene group, an azadibenzogermole group, an azadibenzothiophene 5-oxide group, an aza-9H-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 pyrazole group, an imidazole group, a triazole group, an oxazole group, an isooxazole 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, (each unsubstituted or substituted with at least one R_10a).

Examples of the “C₅-C₃₀carbocyclic group” and the “C₁-C₃₀heterocyclic group” as used herein include i) a third ring, ii) a fourth ring, iii) a condensed ring in which at least two third rings are condensed, iv) a condensed ring in which at least two fourth rings are condensed, or v) a condensed ring in which at least one third ring and at least one fourth ring are condensed, the third ring may be a cyclopentane group, a cyclopentene group, a furan group, a thiophene group, a pyrrole group, a silole group, a borole group, a phosphole group, a germole group, a selenophene group, an oxazole group, an oxadiazole group, an oxatriazole group, a thiazole group, a thiadiazole group, a thiatriazole group, a pyrazole group, an imidazole group, a triazole group, a tetrazole group, or an azasilole group, and the fourth ring may be an adamantane group, a norbornane group, a norbornene group, a cyclohexane group, a cyclohexene group, a benzene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, or a triazine group.

The “fluorinated C₁-C₆₀alkyl group (or fluorinated C₁-C₂₀alkyl group or the like)”, “fluorinated C₃-C₁₀cycloalkyl group”, “fluorinated C₁-C₁₀heterocycloalkyl group”, and “fluorinated phenyl group” as used herein may respectively be a C₁-C₆₀alkyl group (or C₁-C₂₀alkyl group or the like), a C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, and a phenyl group, each substituted with at least one fluoro group (—F).

Examples of the “fluorinated C₁alkyl group (i.e., a fluorinated methyl group)” may include —CF₃, —CF₂H, and —CFH₂. The “fluorinated C₁-C₆₀alkyl group (or fluorinated C₂₀alkyl group or the like)”, “fluorinated C₃-C₁₀cycloalkyl group”, “fluorinated C₁-C₁₀heterocycloalkyl group”, or “fluorinated phenyl group” may respectively be: i) a fully fluorinated C₁-C₆₀alkyl group (or fully fluorinated C₁-C₂₀alkyl group or the like), fully fluorinated C₃-C₁₀cycloalkyl group, fully fluorinated C₁-C₁₀heterocycloalkyl group, or fully fluorinated phenyl group, in which all hydrogen atoms are substituted with fluoro groups; or ii) a partially fluorinated C₁-C₆₀alkyl group (or partially fluorinated C₁-C₂₀alkyl group or the like), partially fluorinated C₃-C₁₀cycloalkyl group, partially fluorinated heterocycloalkyl group, or partially fluorinated phenyl group, in which some of hydrogen atoms are substituted with fluoro groups.

The “deuterated C₁-C₆₀alkyl group (or deuterated C₁-C₂₀alkyl group or the like)”, “deuterated C₃-C₁₀cycloalkyl group”, “deuterated heterocycloalkyl group”, and “deuterated phenyl group” as used herein may respectively be a C₁-C₆₀alkyl group (or C₁-C₂₀alkyl group or the like), C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, and a phenyl group, each substituted with at least one deuterium. Examples of the “deuterated C₁alkyl group (i.e., a deuterated methyl group)” may include —CD₃, —CD₂H, and —CDH₂. Examples of the “deuterated C₃-C₁₀cycloalkyl group” may include Formula 10-501. The “deuterated C₁-C₆₀alkyl group (or deuterated C₁-C₂₀alkyl group or the like)”, “deuterated C₃-C₁₀cycloalkyl group”, “deuterated heterocycloalkyl group”, or deuterated phenyl group may respectively be: i) a fully deuterated C₁-C₆₀alkyl group (or fully deuterated C₁-C₂₀alkyl group or the like), fully deuterated C₃-C₁₀cycloalkyl group, fully deuterated heterocycloalkyl group, or fully deuterated phenyl group, in which all hydrogen atoms are substituted with deuterium atoms; or ii) a partially deuterated C₁-C₆₀alkyl group (or partially deuterated C₁-C₂₀alkyl group or the like), partially deuterated C₃-C₁₀cycloalkyl group, partially deuterated heterocycloalkyl group, or partially deuterated phenyl group, in which some of hydrogen atoms are substituted with deuterium atoms.

The “(C₁-C₂₀alkyl)′X′ group” refers to a ‘X’ group substituted with at least one C₁-C₂₀alkyl group. For example, The “(C₁-C₂₀alkyl)C₃-C₁₀cycloalkyl group” as used herein refers to a C₃-C₁₀cycloalkyl group substituted with at least one C₁-C₂₀alkyl group, and the “(C₁-C₂₀alkyl)phenyl group” as used herein refers to a phenyl group substituted with at least one C₁-C₂₀alkyl group. Examples of the (C₁alkyl)phenyl group may include a toluyl group.

As used herein, the number of carbons in each group that is substituted (e.g., C₁-C₆₀) excludes the number of carbons in the substituent. For example, a C₁-C₆₀alkyl group can be substituted with a C₁-C₆₀alkyl group. The total number of carbons included in the C₁-C₆₀alkyl group substituted with the C₁-C₆₀alkyl group is not limited to 60 carbons. In addition, more than one C₁-C₆₀alkyl substituent may be present on the C₁-C₆₀alkyl group. This definition is not limited to the C₁-C₆₀alkyl group and applies to all substituted groups that recite a carbon range.

In the present specification, “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, and an azadibenzothiophene 5,5-dioxide group” each refer to a hetero ring in which at least one ring-forming carbon atom is substituted with nitrogen atom and respectively having an identical backbone as “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, and a dibenzothiophene 5,5-dioxide group”.

Substituents of the substituted C₅-C₃₀carbocyclic group, the substituted C₃₀heterocyclic group, the substituted C₁-C₆₀alkyl group, the substituted C₂-C₆₀alkenyl group, the substituted C₂-C₆₀alkynyl group, the substituted C₁-C₆₀alkoxy group, the substituted C₁-C₆₀alkylthio group, the substituted C₃-C₁₀cycloalkyl group, the substituted C₁-C₁₀heterocycloalkyl group, the substituted C₃-C₁₀cycloalkenyl group, the substituted C₁-C₁₀heterocycloalkenyl group, the substituted C₆-C₆₀aryl group, the substituted C₇-C₆₀alkyl aryl group, the substituted C₆-C₆₀aryloxy group, the substituted C₆-C₆₀arylthio group, the substituted C₁-C₆₀heteroaryl group, the substituted C₂-C₆₀alkyl heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group may each independently be:

deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, 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 C₁-C₆₀alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀alkynyl group, a C₁-C₆₀alkoxy group, or a C₁-C₆₀alkylthio group; a C₁-C₆₀alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀alkynyl group, a C₁-C₆₀alkoxy group, or C₁-C₆₀alkylthio group, each substituted with deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, 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 C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₇-C₆₀alkyl aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀arylthio group, a C₁-C₆₀heteroaryl group, a C₂-C₆₀alkyl heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q₁₁)(Q₁₂), —Si(Q₁₃)(Q₁₄)(Q₁₅), —B(Q₁₆)(Q₁₇), —P(═O)(Q₁₈)(Q₁₉), —P(Q₁₈)(Q₁₉), or any combination thereof;

a C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₇-C₆₀alkyl aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀arylthio group, a C₁-C₆₀heteroaryl group, a C₂-C₆₀alkyl heteroaryl group, a monovalent non-aromatic condensed polycyclic group, or a monovalent non-aromatic condensed heteropolycyclic group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, 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 Coo alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀alkynyl group, a C₁-C₆₀alkoxy group, a C₁-C₆₀alkylthio group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₇-C₆₀alkyl aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀arylthio group, a C₁-C₆₀heteroaryl group, a C₂-C₆₀alkyl heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q₂₁)(Q₂₂), —Si(Q₂₃)(Q₂₄)(Q₂₅), —B(Q₂₆)(Q₂₇), —P(═O)(Q₂₈)(Q₂₉), —P(Q₂₈)(Q₂₉), or any combination thereof;

—N(Q₃₁)(Q₃₂), —Si(Q₃₃)(Q₃₄)(Q₃₅), —B(Q₃₆)(Q₃₇), —P(═O)(Q₃₈)(Q₃₉), or —P(Q₃₈) (Q₃₉), or

any combination thereof.

In the present specification, Q₁to Q₉, Q₁₁to Q₁₉, Q₂₁to Q₂₉, and Q₃₁to Q₃₉may each independently be: hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; an amidino group; a hydrazine group; a hydrazone group; a 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-C₆₀alkyl group unsubstituted or substituted with deuterium, a C₁-C₆₀alkyl group, a C₆-C₆₀aryl group, or any combination thereof; a C₂-C₆₀alkenyl group; a C₂-C₆₀alkynyl group; a C₁-C₆₀alkoxy group; a C₁-C₆₀alkylthio group; a C₃-C₁₀cycloalkyl group; a C₁-C₁₀heterocycloalkyl group; a C₃-C₁₀cycloalkenyl group; a C₁-C₁₀heterocycloalkenyl group; a C₆-C₆₀aryl group unsubstituted or substituted with deuterium, a C₁-C₆₀alkyl group, a C₆-C₆₀aryl group, or any combination thereof; a C₆-C₆₀aryloxy group; a C₆-C₆₀arylthio group; a C₁-C₆₀heteroaryl group; a monovalent non-aromatic condensed polycyclic group; or a monovalent non-aromatic condensed heteropolycyclic group.

For example, Q₁to Q₉, Q₁₁to Q₁₉, Q₂₁to Q₂₉, and Q₃₁to Q₃₉may each independently be:

Hereinafter, a compound and an organic light-emitting device according to an embodiment will be described in detail with reference to Synthesis Examples and Examples, however, the present disclosure is not limited thereto. The wording “B was used instead of A” used in describing Synthesis Examples means that an amount of B used was identical to an amount of A used based on molar equivalence.

EXAMPLES
Evaluation Example 1
Manufacture of TOF(E1-62)

Compound E1-62 was deposited on an ITO electrode to form a film containing Compound E1-62 and having a thickness of 1 μm. Then, Al was deposited on the film containing Compound E1-62 to form an Al electrode having a thickness of 800 nm, thereby completing the manufacture of TOF(E1-62), which is a time of flight (TOF) device, having a structure of ITO electrode/film containing Compound E1-62 (1 μm)/Al electrode (800 nm).

Manufacture of TOF(E1-63)

TOF(E1-63), which is a TOF device, having a structure of ITO electrode/film containing Compound E1-63 (1 μm)/Al electrode (800 nm), was manufactured in the same manner as in Manufacture of TOF(E1-62), except that Compound E1-63 was used instead of Compound E1-62.

Measurement of Electron Mobility of Compound E1-62

A voltage of 20 V was applied to TOF(E1-62) by using a voltage source (Keithley 2410 Sourcemeter), and TOF(E1-62) was irradiated with laser light having a wavelength of 337 nm by N₂laser (Optical Building Blocks Corporation, 337 nm, a pulse width: 1 nanosecond (ns)). The time versus current graph of TOF(E1-62) was measured. The results thereof are shown in FIG. 3. Subsequently, the electron mobility of Compound E1-62 was evaluated by using the time versus current graph of TOF(E1-62) in FIG. 3 and Equation 100. The results thereof are shown in Table 1. That is, the electron mobility (cm²/Vs) of Compound E1-62 was calculated by i) substituting “d” in Equation 100 with 1 μm, ii) substituting “t” in Equation 100 with the time corresponding to the intersection point of two tangent lines (see dotted line in FIG. 3) in the time versus current graph (a log-log scale) of TOF(E1-62) in FIG. 3, and iii) substituting “V” in Equation 100 with 20 V (field strength F=2×10⁵V/cm).

Measurement of Electron Mobility of Compound E1-63

The time versus current graph of TOF(E1-63) was measured in the same manner described above and shown in FIG. 3. The electron mobility of Compound E1-63 was calculated by using the time versus current graph of TOF(E1-63) shown in FIG. 3 and Equation 100. The results thereof are shown in Table 1.

TABLE 1

Compound
Electron mobility (cm²/Vs)

E1-62
2.8 × 10⁻⁵

E1-63
1.4 × 10⁻⁵

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Referring to the results of Table 1, the electron mobility of Compound E1-62 was found to be greater than the electron mobility of Compound E1-63.

Synthesis Example 1 (D-Ir(1))

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Synthesis of Compound 1390A

33.1 millimole (mmol) of 4-isobutyl-2-phenyl-5-(trimethylsilyl)pyridine and 5.2 grams (g) (14.7 mmol) of iridium chloride (IrCl₃(H₂O)_n, n=3) were mixed with 120 milliliters (mL) of ethoxyethanol and 40 mL of distilled water. Then, the mixture was stirred under reflux for 24 hours, and then the temperature was dropped to room temperature. A solid formed therefrom was separated by filtration. The solid was washed sufficiently with water, methanol, and hexane in the stated order and dried in a vacuum oven to thereby obtain 7.4 g of Compound 1390A (yield: 74%).

Synthesis of Compound 1390B

1.2 mmol of Compound 1390A was mixed with 45 mL of methylene chloride (MC), and a solution, in which 0.6 g (2.3 mmol) of AgOTf was dissolved in 15 mL of methanol (MeOH), was added thereto. Then, the mixture was stirred for 18 hours at room temperature while blocking light by using an aluminum foil. The resulting mixture was celite-filtered to remove a solid formed therefrom and the filtrate was concentrated under reduced pressure to thereby obtain a solid (Compound 1390B). The solid was used in the following reaction without any further purification.

Synthesis of D-Ir(1) (Compound 1390 of Group 1-3)

2.3 mmol of Compound 1390B and 2.8 mmol of 1-(3,5-diisopropyl-[1,1′-biphenyl]-4-yl)-2-(7-phenyldibenzo[b,d]furan-4-yl)-1H-benzo[d]imidazole were mixed with 50 mL of 2-ethoxyethanol and 50 mL of N,N-dimethylformamide, followed by stirring under reflux for 48 hours. Then, the temperature was lowered to room temperature. The thus obtained mixture was concentrated under reduced pressure to obtain a solid which then was subjected to column chromatography (eluent: methylene chloride (MC) and hexane) to thereby obtain 0.56 g of D-Ir(1) (Compound 1390 of Group 1-3) (yield: 39%). The resulting compound was identified by using mass spectroscopy and HPLC analysis.

HRMS (MALDI) calcd. for C₇₉H₈₃IrN₄OSi₂: m/z 1352.5735. Found: 1352.5733. Example 1

A glass substrate, on which an anode having an ITO/Ag/ITO (70 Å/1,000 Å/70 Å) structure was deposited, was cut to a size of 50 millimeters (mm)×50 mm×0.5 mm, sonicated in isopropyl alcohol and water for 5 minutes each, and cleaned by exposure to ultraviolet rays and ozone for 30 minutes. Subsequently, the glass substrate was mounted on a vacuum-deposition device.

Compound HT3 and Compound F6-TCNNQ were co-vacuum-deposited on the anode at a weight ratio of 98:2 to form a hole injection layer having a thickness of 10 nm and Compound HT3 was then vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 155 nm. Compound HT(1) was vacuum-deposited on the hole transport layer to form an electron blocking layer having a thickness of 30 nm.

Subsequently, Ir(ppy)₃as a first dopant and a first hole-transporting compound (HT(1)) and a first electron-transporting compound (E1-63) as hosts were co-deposited on the electron blocking layer to form a first emission layer having a thickness of 10 nm and Ir(ppy)₃as a second dopant and the second hole-transporting compound (HT(1)) and the second electron-transporting compound (E1-62) as hosts were co-deposited on the first emission layer to form a second emission layer having a thickness of 23 nm, thereby forming an emission layer. A content of the first dopant in the first emission layer was 7 parts by weight based on 100 parts by weight of the first emission layer. A weight ratio of the first hole-transporting compound to the first electron-transporting compound in the first emission layer was 6:4 as shown in Table 2 (see the weight ratio in the parenthesis in Table 2). A content of the second dopant in the second emission layer was 7 parts by weight based on 100 parts by weight of the second emission layer. A weight ratio of the second hole-transporting compound to the second electron-transporting compound in the second emission layer was 6.5:3.5 as shown in Table 2.

Compound ET3 and Compound ET-D1 were co-deposited at a volume ratio of 50:50 on the emission layer to form an electron transport layer having a thickness of 35 nm, LiF was deposited on the electron transport layer to form an electron injection layer having a thickness of 1 nm, and Mg and Ag were co-deposited at a weight ratio of 90:10 on the electron injection layer to form a cathode having a thickness of 12 nm, thereby completing the manufacture of an organic light-emitting device. Compound HT(1) was identical to Compound H1-8 of Group 5-2 provided herein.

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Examples 2 to 4 and Comparative Examples 1 to 4

Organic light-emitting devices were each manufactured in the same manner as in Example 1, except that an emission layer was formed as shown in Table 2 (Comparative Example 1 did not include a second emission layer, and Comparative Example 2 did not include a first emission layer.)

TABLE 2

First emission layer
Second emission layer

First
Thickness

Second
Thickness

Host
dopant
(nm)
Host
dopant
(nm)

Example 1
HT(1)
E1-63
Ir(ppy)₃
10
HT(1)
E1-62
Ir(ppy)₃
23

(6:4)

(6.5:3.5)

Example 2
HT(1)
E1-63
Ir(ppy)₃
15
HT(1)
E1-62
Ir(ppy)₃
18

(6:4)

(6.5:3.5)

Example 3
HT(1)
E1-63
Ir(ppy)₃
20
HT(1)
E1-62
Ir(ppy)₃
13

(6:4)

(6.5:3.5)

Example 4
HT(1)
E1-63
Ir(ppy)₃
10
HT(1)
E1-62
Ir(ppy)₃
23

(6:4)

(5.5:4.5)

Comparative
HT(1)
E1-63
Ir(ppy)₃
33
—

Example 1
(6:4)

Comparative
—
HT(1)
E1-62
Ir(ppy)₃
33

Example 2

(6.5:3.5)

Comparative
HT(1)
E1-62
Ir(ppy)₃
10
HT(1)
E1-63
Ir(ppy)₃
23

Example 3
(6:4)

(6.5:3.5)

Comparative
HT(1)
E1-63
Ir(ppy)₃
10
E1-63
E1-62
Ir(ppy)₃
23

Example 4
(6:4)

(6.5:3.5)

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Examples 11 to 14

Organic light-emitting devices were each manufactured in the same manner as in Example 1, except that an emission layer was formed as shown in Table 3.

TABLE 3

First emission layer
Second emission layer

First
Thickness

Second
Thickness

Host
dopant
(nm)
Host
dopant
(nm)

Example 11
HT(1)
E1-63
D-Ir(1)
10
HT(1)
E1-62
D-Ir(1)
23

(6:4)

(6.5:3.5)

Example 12
HT(1)
E1-63
D-Ir(1)
15
HT(1)
E1-62
D-Ir(1)
18

(6:4)

(6.5:3.5)

Example 13
HT(1)
E1-63
D-Ir(1)
20
HT(1)
E1-62
D-Ir(1)
13

(6:4)

(6.5:3.5)

Example 14
HT(1)
E1-63
D-Ir(1)
10
HT(1)
E1-62
D-Ir(1)
23

(6:4)

(5.5:4.5)

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Evaluation Example 2

The driving voltage (V) (at 15,000 nit), luminescence efficiency versus current density (cd/A) (at 15,000 nit), luminescence efficiency versus power (cd/W) (at 15,000 nit), and lifespan (hours) (at 30,000 nit) of the organic light-emitting devices manufactured in Examples 1 to 4 and 11 to 14 and Comparative Examples 1 to 4 were evaluated. The results thereof are shown in Table 4. A Keithley 2400 current voltmeter and a luminance meter (Minolta Cs-1000A) were used in the evaluation. The lifespan (LT₉₇) refers to time (hours) required for the initial luminance of the organic light-emitting device to reduce to 97% thereof. The luminescence efficiency versus current density, luminescence efficiency versus power, and lifespan (LT₉₇) shown in Table 4 are each shown in relative values (%).

TABLE 4

Luminescence
Luminescence

efficiency
efficiency

versus
versus

current density
power

(at driving
(at driving
Lifespan

Driving
voltage)
voltage)
(LT₉₇)

voltage
(relative
(relative
(relative

(V)
value, %)
value, %)
value, %)

Example 1
3.8
72
20
18

Example 2
3.8
72
20
19

Example 3
3.9
73
20
19

Example 4
3.8
72
21
17

Comparative
4.3
64
16
17

Example 1

Comparative
3.9
71
20
14

Example 2

Comparative
4.1
64
17
5

Example 3

Comparative
3.6
67
20
1

Example 4

Example 11
3.4
100
99
93

Example 12
3.4
100
99
94

Example 13
3.4
99
100
100

Example 14
3.3
98
100
84

Referring to the results of Table 4, the organic light-emitting devices of Examples 1 to 4 and 11 to 14 were found to have improved driving voltage, luminescence efficiency (luminescence efficiency versus current density and luminescence efficiency versus power), and/or lifespan, as compared with the organic light-emitting devices of Comparative Examples 1 to 4.

As apparent from the foregoing description, the light-emitting device may have excellent driving voltage, excellent luminescence efficiency, and/or excellent lifespan characteristics, and thus, a high-quality electronic apparatus may be manufactured by using the light-emitting device.

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.

LIGHT-EMITTING DEVICE AND ELECTRONIC APPARATUS INCLUDING SAME

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