Patent Description:
Organic light-emitting devices are self-emissive devices that produce full-color images, and also have wide viewing angles, high contrast ratios, and short response times, as well as excellent characteristics in terms of luminance, driving voltage, and/or response speed.

The organic light-emitting device may include a first electrode on a substrate, and a hole transport region, an emission layer, an electron transport region, and a second electrode, which are sequentially positioned on the first electrode. Holes provided from the first electrode may move toward the emission layer through the hole transport region, and electrons provided from the second electrode may move toward the emission layer through the electron transport region. Carriers, such as holes and electrons, recombine in the emission layer to produce excitons. These excitons transition from an excited state to a ground state, thereby generating light.

<CIT> discloses a light-emitting element that includes a cathode, an anode, a light-emitting layer, a first layer, a second layer, and a third layer.

<CIT> discloses an organic light-emitting diode device.

One or more aspects of embodiments of the present disclosure are directed toward an organic light-emitting device having a low driving voltage, high efficiency, and long lifespan.

According to an embodiment, provided is an organic light-emitting device including a first electrode,.

According to another embodiment, provided is a flat-display apparatus including a thin-film transistor including a source electrode, a drain electrode, and an activation layer; and the organic light-emitting device, wherein the first electrode of the organic light-emitting device is electrically coupled with one selected from the source electrode and the drain electrode of the thin-film transistor.

Reference will now be made in more detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. Expressions such as "at least one selected from," "one of," and "selected from," when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.

According to an embodiment, provided is an organic light-emitting device including: a first electrode;.

The material was spin-coated on an ITO substrate to form a <NUM> thin film, and then heat-treated for <NUM> minutes at <NUM> on a hot plate in air, and the work function was evaluated. The equipment used for the evaluation was UPS (Ultraviolet Photoelectron Spectroscopy).

<FIG> is a schematic cross-sectional view of an organic light-emitting device <NUM> according to an embodiment. As shown in <FIG>, the organic light-emitting device <NUM> according to an embodiment includes a first electrode <NUM>, a second electrode <NUM> facing the first electrode <NUM>, m emission units <NUM> stacked between the first electrode <NUM> and the second electrode <NUM>, and m-<NUM> charge generating layers <NUM> between two adjacent emission units among the m emission units <NUM>, each of the charge generating layers <NUM> including one n-type charge generating layer <NUM>' and one p-type charge generating layer <NUM>".

An emission unit of the m emission units <NUM> is not particularly limited as long as the emission unit has a function capable of emitting light. For example, the emission unit includes at least one emission layer. In some embodiments, the emission unit may further include an organic layer, in addition to an emission layer.

The organic light-emitting device <NUM> includes m stacked emission units <NUM>, and m is an integer of <NUM> or more. m (which is the number of the emission units) may be selected, as necessary, and the maximum number of the emission units is not particularly limited. For example, the organic light-emitting device may include two, three, four, or five emission units.

In one or more embodiments, a maximum emission wavelength of light emitted from at least one emission unit among the m emission units may be different from a maximum emission wavelength of light emitted from at least one emission unit among other (remaining) emission units. For example, in an organic light-emitting device in which a first emission unit and a second emission unit are stacked, a maximum emission wavelength of light emitted from the first emission unit may be different from a maximum emission wavelength of light emitted from the second emission unit. In this regard, emission layers in the first emission unit and the second emission unit may each independently include i) a single-layered structure including (e.g., consisting of) a single layer including (e.g., consisting of) a single material, ii) a single-layered structure including (e.g., consisting of) a single layer including (e.g., consisting of) a plurality of different materials, or iii) a multi-layered structure having a plurality of layers including (e.g., consisting of) a plurality of different materials. Accordingly, light emitted from the first emission unit or the second emission unit may be single-color light or mixed-color light. In one or more embodiments, in an organic light-emitting device in which a first emission unit, a second emission unit, and a third emission unit are stacked, a maximum emission wavelength of light emitted from the first emission unit may be identical to a maximum emission wavelength of light emitted from the second emission unit, but may be different from a maximum emission wavelength of light emitted from the third emission unit. In some embodiments, a maximum emission wavelength of light emitted from the first emission unit, a maximum emission wavelength of light emitted from the second emission unit, and a maximum emission wavelength of light emitted from the third emission unit may be different from one another.

In one or more embodiments, maximum emission wavelengths of light respectively emitted from the m emission units may be identical to each other.

In one or more embodiments, maximum emission wavelengths of light respectively emitted from the m emission units may each independently be selected in a range of about <NUM> to about <NUM>. For example, the maximum emission wavelengths of light respectively emitted from the m emission units may each independently be selected in a range of about <NUM> to about <NUM>, about <NUM> to about <NUM>, or about <NUM> to about <NUM>.

The organic light-emitting device <NUM> includes a charge generating layer <NUM> between two adjacent emission units <NUM> among the m emission units <NUM>, wherein the term "adjacent" refers to an arrangement relationship between layers that are closest to each other among layers that are described to be adjacent. For example, the two adjacent emission units refers to an arrangement relationship between two emission units that are located most closely to each other among a plurality of emission units. The "adjacent", in some cases, may refer to a case in which two layers are physically in contact with each other or a case in which another layer (that may not be described) may be located between the two layers. For example, an emission unit adjacent to a second electrode refers to, among a plurality of emission units, an emission unit that is located most closely to the second electrode. In some embodiments, the second electrode may be physically in contact with the emission unit, but in other embodiments, other layers may be located between the second electrode and the emission unit. For example, an electron transport layer may be located between the second electrode and the emission unit. However, a charge generating layer is located between two adjacent emission units.

The charge generating layer is a layer acting as a cathode with respect to one emission unit among two adjacent emission units, by generating electron(s), and an anode with respect to the other emission unit among the two adjacent emission units, by generating hole(s), and the charge generating layer refers to a layer that is not directly connected with an electrode, but that separates adjacent emission units. An organic light-emitting device including m emission units includes m-<NUM> charge generating layers.

The charge generating layer <NUM> includes the n-type charge generating layer <NUM>' and the p-type charge generating layer <NUM>". In this regard, the n-type charge generating layer <NUM>' and the p-type charge generating layer <NUM>" may be in direct contact with each other to form an N-P junction. Due to the N-P junction, an electron and a hole may be simultaneously (or concurrently) generated between the n-type charge generating layer <NUM>' and the p-type charge generating layer <NUM>". The generated electron may be transferred, via the n-type charge generating layer <NUM>', to one emission unit among two adjacent emission units. The generated hole may be transferred, via the p-type charge generating layer <NUM>", to the other emission unit among the two adjacent emission units. In addition, when charge generating layers <NUM> each include one n-type charge generating layer <NUM>' and one p-type charge generating layer <NUM>", the organic light-emitting device <NUM> including the m-<NUM> charge generating layers <NUM> may include n-type charge generating layers <NUM>' in the number of m-<NUM> and p-type charge generating layers <NUM>" in the number of m-<NUM>.

The "n-type" refers to n-type semiconductor characteristics, for example, electron injection characteristics or electron transport characteristics. The "p-type" refers to p-type semiconductor characteristics, for example, hole injection characteristics or hole transport characteristics.

At least one of the p-type charge generating layers <NUM>" in the number of m-<NUM> includes a first inorganic material, wherein the first inorganic material is a compound including a post transition metal and a metalloid.

For example, the compound including a post transition metal and a metalloid may be an alloy including the post transition metal and the metalloid. For example, the compound including a post transition metal and a metalloid may be a compound consisting of the post transition metal and the metalloid.

In one or more embodiments, when the first inorganic material is a compound including a post transition metal and a metalloid, a composition ratio of the post transition metal and the metalloid may be from <NUM> : <NUM> to <NUM> : <NUM>. For example, the composition ratio of the post transition metal and the metalloid may be from <NUM> : <NUM> to <NUM> : <NUM>. For example, the composition ratio of the post transition metal and the metalloid may be from <NUM> : <NUM> to <NUM> : <NUM>. For example, the composition ratio of the post transition metal and the metalloid may be from <NUM> : <NUM> to <NUM> : <NUM>. For example, the composition ratio of the post transition metal and the metalloid may be from <NUM> : <NUM> to <NUM> : <NUM>. For example, the composition ratio of the post transition metal and the metalloid may be from <NUM> : <NUM> to <NUM> : <NUM>. For example, the composition ratio of the post transition metal and the metalloid may be from <NUM> : <NUM> to <NUM> : <NUM>. For example, the composition ratio of the post transition metal and the metalloid may be from <NUM> : <NUM> to <NUM> : <NUM>.

For example, an amount of the metalloid in the first inorganic material may be greater than or equal to an amount of the post transition metal in the first inorganic material.

In one or more embodiments, an absolute value of a work function of the first inorganic material may be <NUM> eV or more. For example, the absolute value of a work function of the first inorganic material may be <NUM> eV or more. For example, the absolute value of a work function of the first inorganic material may be <NUM> eV or more.

The post transition metal is at least one selected from aluminium (Al), gallium (Ga), indium (In), thallium (TI), tin (Sn), lead (Pb), flerovium (Fl), bismuth (Bi), and polonium (Po).

In one or more embodiments, the post transition metal may be at least one selected from Al, Ga, In, Tl, Sn, Pb, Fl, and Bi. In one or more embodiments, the post transition metal may be at least one selected from Al, Ga, In, Tl, Sn, Pb, and Bi.

For example, the post transition metal may be any combination of two or more selected from Al, Ga, In, Tl, Sn, Pb, Fl, and Bi, and post transition metals of any combination selected therefrom may be included in the compound including a post transition metal and a metalloid.

In one or more embodiments, the metalloid may be at least one selected from Si, Ge, As, Sb, and Te.

For example, the metalloid may be any combination of two or more selected from Si, Ge, As, Sb, and Te, and metalloids of any combination selected therefrom may be included in the compound including a post transition metal and a metalloid.

In one or more embodiments, the first inorganic material may be at least one selected from Bi<NUM>Te<NUM>, Bi<NUM>Te<NUM>, Bi<NUM>Te, Bi<NUM>Te<NUM>, BiTe, Bi<NUM>Te<NUM>, Bi<NUM>Te<NUM>, BixTey(<NUM><x<<NUM>, <NUM><y<<NUM>, <NUM><x+y≤<NUM>), In<NUM>Te<NUM>, Ga<NUM>Te<NUM>, Al<NUM>Te<NUM>, Tl<NUM>Te<NUM>, SnTe, PbTe, FITe, AlInSb, AlGaSb, AlAsSb, GaAs, InSb, AlSb, AlAs, AlaInaSb (<NUM><a<<NUM>), AlbIn(<NUM>-b)Sb (<NUM><b<<NUM>), AlSb, GaSb, and AlInGaAs. For example, the first inorganic material may be at least one selected from Bi<NUM>Te<NUM>, Bi<NUM>Te<NUM>, Bi<NUM>Te, Bi<NUM>Te<NUM>, BiTe, Bi<NUM>Te<NUM>, Bi<NUM>Te<NUM>, BixTey(<NUM><x<<NUM>, <NUM><y<<NUM>, <NUM><x+y≤<NUM>), In<NUM>Te<NUM>, Ga<NUM>Te<NUM>, Al<NUM>Te<NUM>, Tl<NUM>Te<NUM>, SnTe, PbTe, AlInSb, AlGaSb, AlAsSb, GaAs, InSb, AlSb, AlAs, AlaInaSb (<NUM><a<<NUM>), AlbIn(<NUM>-b)Sb (<NUM><b<<NUM>), AlSb, GaSb, and AlInGaAs.

For example, the first inorganic material may be at least one selected from Bi<NUM>Te<NUM>, Bi<NUM>Te<NUM>, Bi<NUM>Te, Bi<NUM>Te<NUM>, BiTe, Bi<NUM>Te<NUM>, Bi<NUM>Te<NUM>, and BixTey(<NUM><x<<NUM>, <NUM><y<<NUM>, <NUM><x+y≤<NUM>).

In one or more embodiments, a thermal evaporation temperature of the first inorganic material may be <NUM>,<NUM> or less. For example, the thermal evaporation temperature of the first inorganic material may be from <NUM> to <NUM>,<NUM>. For example, the thermal evaporation temperature of the first inorganic material may be from <NUM> to <NUM>,<NUM>. For example, the thermal evaporation temperature of the first inorganic material may be from <NUM> to <NUM>,<NUM>. For example, the thermal evaporation temperature of the first inorganic material may be from <NUM> to <NUM>. For example, the thermal evaporation temperature of the first inorganic material may be from <NUM> to <NUM>.

The n-type charge generating layers <NUM>' include a metal and may further include a metal-free compound including at least one π electron-deficient nitrogen-containing ring, a compound represented by Formula <NUM>, a metal oxide, a metal carbide, a metal halide, or any mixture thereof:.

Formula <NUM>     [Ar<NUM>]xe11-[(L<NUM>)xe1-R<NUM>]xe21.

The "π electron-deficient nitrogen-containing ring" is the same as described in connection with an electron transport region described herein below.

The metal may be an alkali metal, an alkaline earth metal, a rare earth metal, a transition metal, a late transition metal, a metalloid, or any combination thereof, but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, when at least one of the n-type charge generating layers <NUM>' in the number of m-<NUM> includes the metal oxide, the metal oxide may be an alkali metal oxide, but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, when at least one of the n-type charge generating layers <NUM>' in the number of m-<NUM> includes the metal halide, the metal halide may be an alkali metal halide, but embodiments of the present disclosure are not limited thereto.

For example, at least one of the n-type charge generating layers <NUM>' in the number of m-<NUM> may include at least one selected from Yb, Ag, Al, Sm, Mg, Li, Rbl, Ti, Rb, Na, K, Ba, Mn, and YbSi<NUM>, but embodiments of the present disclosure are not limited thereto. In one or more embodiments, at least one of the n-type charge generating layers <NUM>' in the number of m-<NUM> may include at least one selected from Yb, Ag, and Al, but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, at least one of the p-type charge generating layers <NUM>" in the number of m-<NUM> may include the first inorganic material and a hole transport material.

The hole transport material is not particularly limited as long as the hole transport material is a material having hole transport characteristics, and for example, may be selected from a group represented by Formula <NUM>, a group represented by Formula <NUM>, and a group represented by Formula <NUM>-<NUM>. <CHM>
<CHM>
<CHM>
<CHM>.

In Formulae <NUM>, <NUM> and <NUM>-<NUM>,.

For example, an amount of a first inorganic material included in the p-type charge generating layer <NUM>" may be selected in a range of <NUM> parts by weight to <NUM> parts by weight, based on <NUM> parts by weight of the hole transport material. For example, an amount of a first inorganic material included in the p-type charge generating layer <NUM>" may be selected in a range of <NUM> parts by weight to <NUM> parts by weight, based on <NUM> parts by weight of the hole transport material. For example, an amount of a first inorganic material included in the p-type charge generating layer <NUM>" may be selected in a range of <NUM> parts by weight to <NUM> parts by weight, based on <NUM> parts by weight of the hole transport material.

In one or more embodiments, a thickness of the n-type charge generating layer <NUM>' and a thickness of the p-type charge generating layer <NUM>" may each independently be in a range of about 5Å to about <NUM>Å. For example, the thickness of the n-type charge generating layer <NUM>' and the thickness of the p-type charge generating layer <NUM>" may each independently be in a range of about 20Å to about <NUM>Å, but embodiments of the present disclosure are not limited thereto. For example, the thickness of the n-type charge generating layer <NUM>' and the thickness of the p-type charge generating layer <NUM>" may each independently be in a range of about 20Å to about <NUM>Å, but embodiments of the present disclosure are not limited thereto. When the thicknesses of the n-type charge generating layer <NUM>' and the p-type charge generating layer <NUM>" are within any of these ranges, a high-quality (or improved) organic light-emitting device may be implemented without a substantial increase in driving voltage.

<FIG> is a schematic cross-sectional view of an organic light-emitting device <NUM> according to an embodiment.

As in <FIG>, the organic light-emitting device <NUM> of <FIG> includes a first electrode <NUM>, a second electrode <NUM> facing the first electrode <NUM>, m emission units <NUM> stacked between the first electrode <NUM> and the second electrode <NUM>, and m-<NUM> charge generating layers <NUM> between two adjacent emission units among the m emission units <NUM>, each of the charge generating layers <NUM> including one n-type charge generating layer <NUM>' and one p-type charge generating layer <NUM>".

In this regard, at least one of the m-<NUM> charge generating layers <NUM> may further include an interlayer 155a between an n-type charge generating layer <NUM>' and a p-type charge generating layer <NUM>".

In one or more embodiments, the interlayer 155a may include the first inorganic material.

The first inorganic material included in the interlayer 155a is the same as described in connection with the first inorganic material described above.

For example, a first inorganic material included in at least one of the p-type charge generating layers <NUM>" in the number of m-<NUM> may be identical to a first inorganic material included in the interlayer 155a.

For example, a first inorganic material included in at least one of the p-type charge generating layers <NUM>" in the number of m-<NUM> may be different from a first inorganic material included in the interlayer 155a.

In one or more embodiments, an absolute value of a work function of the interlayer 155a may be greater than or equal to an absolute value of a work function of the n-type charge generating layer <NUM>', and less than or equal to an absolute value of a work function of the p-type charge generating layer <NUM>".

In one or more embodiments, when at least one of the p-type charge generating layers <NUM>" in the number of m-<NUM> includes the first inorganic material and a hole transport material, the organic light-emitting device <NUM> may include the interlayer 155a between a p-type charge generating layer <NUM>" including the first inorganic material and the hole transport material and an n-type charge generating layer <NUM>'.

In one or more embodiments, the organic light-emitting devices <NUM> and <NUM> may each further include a second inorganic material that is at least one selected from a halide compound of a transition metal, a halide compound of a late transition metal, and any combination thereof.

The transition metal is not particularly limited, but may be a transition metal of Group <NUM> to Group <NUM>, for example, at least one selected from copper (Cu), nickel (Ni), and zinc (Zn). The late transition metal is not particularly limited, but may be at least one selected from aluminium (Al), gallium (Ga), indium (In), thallium (TI), tin(Sn), lead(Pb), flerovium (FI), bismuth (Bi), and polonium (Po).

Here, the halide compound refers to a material formed by bonding with a halogen, and the halogen may be, for example, at least one selected from F, Cl, Br, and I.

When the organic light-emitting devices <NUM> and <NUM> further include the second inorganic material, hole carriers are additionally supplied to a charge generating layer, and thus electrical characteristics/charge generation characteristics of the charge generating layer may be improved.

For example, the second inorganic material may be at least one selected from CuF, CuCl, CuBr, Cul, NiF<NUM>, NiCl<NUM>, NiBr<NUM>, NiI<NUM>, ZnF<NUM>, ZnCl<NUM>, ZnBr<NUM>, ZnI<NUM>, ZnF<NUM>, and ZnI<NUM>, but embodiments of the present disclosure are not limited thereto.

For example, the second inorganic material may be included in: i) a charge generating layer including a first inorganic material among the n-type charge generating layer <NUM>' and the p-type charge generating layer <NUM>";.

In this regard, the auxiliary layer may be in a form of a single layer including (e.g., consisting of) the second inorganic material.

For example, the organic light-emitting device <NUM> includes the interlayer 155a including the first inorganic material and may further include an auxiliary layer (not shown) including the second organic material between the interlayer 155a and the n-type charge generating layer <NUM>' or the interlayer 155a and the p-type charge generating layer <NUM>". In this regard, among the n-type charge generating layer <NUM>' and the p-type charge generating layer <NUM>", a charge generating layer including a first inorganic material may further include the second inorganic material.

When the charge generating layer including a first inorganic material includes the second inorganic material, an amount of the second inorganic material included in the charge generating layer may be selected in a range of about <NUM> by parts by weight to about <NUM> parts by weight, based on <NUM> parts by weight of the first inorganic material. For example, the amount of the second inorganic material included in the charge generating layer may be selected in a range of about <NUM> parts by weight to about <NUM> parts by weight, based on <NUM> parts by weight of the first inorganic material.

In the organic light-emitting device, m may be <NUM> or <NUM>. An embodiment of an organic light-emitting device where m is <NUM> is the same as that described in connection with <FIG>, and an embodiment of an organic light-emitting device where m is <NUM> is the same as that described in connection with <FIG>.

In one or more embodiments, in the organic light-emitting device, m may be <NUM>,.

Referring to <FIG>, an organic light-emitting device <NUM> includes: a first electrode <NUM>; a second electrode <NUM> facing the first electrode <NUM>; a first emission unit <NUM>-<NUM> stacked between the first electrode <NUM> and the second electrode <NUM>; a second emission unit <NUM>-<NUM> stacked between the first emission unit <NUM>-<NUM> and the second electrode <NUM>; and a charge generating layer <NUM> between the first emission unit <NUM>-<NUM> and the second emission unit <NUM>-<NUM>, wherein the first emission unit <NUM>-<NUM> is located between the first electrode <NUM> and the charge generating layer <NUM>, the second emission unit <NUM>-<NUM> is located between the charge generating layer <NUM> and the second electrode <NUM>, the charge generating layer <NUM> includes an n-type charge generating layer <NUM>' and a p-type charge generating layer <NUM>", the n-type charge generating layer <NUM>' is located between the first emission unit <NUM>-<NUM> and the second emission unit <NUM>-<NUM>, and the p-type charge generating layer <NUM>" is located between the n-type charge generating layer <NUM>' and the second emission unit <NUM>-<NUM>.

In some embodiments, the organic light-emitting device <NUM> may further include the interlayer between the n-type charge generating layer <NUM>' and the p-type charge generating layer <NUM>".

In one or more embodiments, in the organic light-emitting device of the present embodiments, m may be <NUM>,.

Referring to <FIG>, an organic light-emitting device <NUM> includes: a first electrode <NUM>; a second electrode <NUM> facing the first electrode <NUM>; a first emission unit <NUM>-<NUM> stacked between the first electrode <NUM> and the second electrode <NUM>; a second emission unit <NUM>-<NUM> stacked between the first emission unit <NUM>-<NUM> and the second electrode <NUM>; a third emission unit <NUM>-<NUM> stacked between the second emission unit <NUM>-<NUM> and the second electrode <NUM>; a first charge generating layer <NUM>-<NUM> between the first emission unit <NUM>-<NUM> and the second emission unit <NUM>-<NUM>; and a second charge generating layer <NUM>-<NUM> between the second emission unit <NUM>-<NUM> and the third emission unit <NUM>-<NUM>, wherein the first emission unit <NUM>-<NUM> is located between the first electrode <NUM> and the first charge generating layer <NUM>-<NUM>, the second emission unit <NUM>-<NUM> is located between the first charge generating layer <NUM>-<NUM> and the second charge generating layer <NUM>-<NUM>, the third emission unit <NUM>-<NUM> is located between the second charge generating layer <NUM>-<NUM> and the second electrode <NUM>, the first charge generating layer <NUM>-<NUM> includes a first n-type charge generating layer <NUM>'-<NUM> and a first p-type charge generating layer <NUM>"-<NUM>, the first n-type charge generating layer <NUM>'-<NUM> is located between the first emission unit <NUM>-<NUM> and the second emission unit <NUM>-<NUM>, the first p-type charge generating layer <NUM>"-<NUM> is located between the first n-type charge generating layer <NUM>'-<NUM> and the second emission unit <NUM>-<NUM>, the second charge generating layer <NUM>-<NUM> includes a second n-type charge generating layer <NUM>'-<NUM> and a second p-type charge generating layer <NUM>"-<NUM>, the second n-type charge generating layer <NUM>'-<NUM> is located between the second emission unit <NUM>-<NUM> and the third emission unit <NUM>-<NUM>, and the second p-type charge generating layer <NUM>"-<NUM> is located between the second n-type charge generating layer <NUM>'-<NUM> and the third emission unit <NUM>-<NUM>.

In some embodiments, the organic light-emitting device <NUM> may further include the interlayer described above between the first n-type charge generating layer <NUM>'-<NUM> and the first p-type charge generating layer <NUM>"-<NUM> and/or between the second n-type charge generating layer <NUM>'-<NUM> and the second p-type charge generating layer <NUM>"-<NUM>. For example, the interlayer may only be present between the first n-type charge generating layer <NUM>'-<NUM> and the first p-type charge generating layer <NUM>"-<NUM> or between the second n-type charge generating layer <NUM>'-<NUM> and the second p-type charge generating layer <NUM>"-<NUM>, or may be present between the first n-type charge generating layer <NUM>'-<NUM> and the first p-type charge generating layer <NUM>"-<NUM>, and between the first second n-type charge generating layer <NUM>'-<NUM> and the second p-type charge generating layer <NUM>"-<NUM>.

In the related art, in a device in which two or more emission layers are sequentially stacked, a charge generating layer between the two or more emission layers may include an oxide or an organic material, wherein the oxide or the organic material has a deep lowest unoccupied molecular orbital (LUMO) energy level.

However, in the case of an oxide, a thermal evaporation temperature may be greater than <NUM>,<NUM>, which is extremely high, and in the case of an organic material, thermal evaporation may be achieved, but the price of the device may be extremely expensive.

Because in an organic light-emitting device according to the present disclosure, a charge generating layer, for example, a p-type charge generating layer, includes a first inorganic material capable of thermal deposition including a post transition metal and a metalloid, the resulting device may be characterized by low driving voltage and higher current density at the same voltage, while thermal evaporation may be achieved in a low temperature, and may have excellent characteristics in terms of color purity and efficiency that are greater than or equal to those of devices in the related art. Because the first inorganic material has a low thermal evaporation temperature compared to related metal materials, a thermal evaporation process may be achieved.

In addition, when the first inorganic material is a compound including a post transition metal and a metalloid, a work function of the first inorganic material may be adjusted by adjusting a ratio of the post transition metal and the metalloid. Thus, a barrier between an n-type charge generating layer and a p-type charge generating layer may be adjusted such that charge may be efficiently (or suitably) generated. For example, as a ratio of a metalloid increases, an absolute value of a work function of a first inorganic material increases, and for example, an amount of a metalloid may be greater than or equal to an amount of a post transition metal.

Table <NUM> shows work functions according to ratios of Bi and Te as compounds (post transition metal and metalloid, respectively) in the first inorganic material according to an embodiment.

As shown in Table <NUM>, as a ratio of Te, which is a metalloid, increases, an absolute value of a work function generally (mostly) increases.

In addition, the organic light-emitting device may include the first inorganic material as a single-layered structure in a charge generating layer, or may include a hole transport material as well as the first inorganic material in a charge generating layer, and thus may include the first inorganic material as a dopant.

As described above, when an organic light-emitting device includes a hole transport material as well as the first inorganic material, electrical conductivity of a hole injection layer may increase, and thus charge may be efficiently (or suitably) generated, and hole transport to an adjacent emission unit may be further facilitated, resulting in improvement of efficiency of the device.

In addition, the organic light-emitting device may optionally further include an interlayer including the first inorganic material between an n-type charge generating layer and a p-type charge generating layer, and thus a barrier between the n-type charge generating layer and the p-type charge generating layer may be lowered, and N-P junction may be further facilitated, resulting in lowering driving voltage.

According to another embodiment, provided is a flat-display apparatus including: a thin-film transistor including a source electrode, a drain electrode, and an activation layer; and the organic light-emitting device, wherein the first electrode of the organic light-emitting device is electrically connected (coupled) with one selected from the source electrode and the drain electrode of the thin-film transistor.

The term "organic layer" as used herein refers to a single layer and/or a plurality of layers located between the first electrode and the second electrode of an organic light-emitting device. A material included in the "organic layer" is not limited to an organic material.

Hereinafter, structures of the organic light-emitting devices <NUM>, <NUM>, <NUM>, and <NUM> according to embodiments and methods of manufacturing the same will be described in connection with <FIG>.

In <FIG>, a substrate may be additionally located under the first electrode <NUM> or above the second electrode <NUM>. The substrate may be a glass substrate and/or a plastic substrate, each having excellent (or suitable) mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and/or water resistance.

The first electrode <NUM> may be formed by depositing or sputtering a material for forming the first electrode <NUM> on the substrate. When the first electrode <NUM> is an anode, the material for a first electrode may be selected from materials with a high work function to facilitate hole injection.

The first electrode <NUM> may be a reflective electrode, a semi-transmissive electrode, or a transmissive electrode. When the first electrode <NUM> is a transmissive electrode, a material for forming a first electrode <NUM> may be selected from indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO<NUM>), zinc oxide (ZnO), and any combination thereof, but embodiments of the present disclosure are not limited thereto. In one or more embodiments, when the first electrode <NUM> is a semi-transmissive electrode or a reflective electrode, a material for forming a first electrode may be selected from magnesium (Mg), silver (Ag), aluminium (Al), aluminium-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), and any combination thereof, but embodiments of the present disclosure are not limited thereto.

The first electrode <NUM> may have a single-layered structure or a multi-layered structure including two or more layers. For example, the first electrode <NUM> may have a three-layered structure of ITO/Ag/ITO, but the structure of the first electrode <NUM> is not limited thereto.

The organic layer <NUM> is located on the first electrode <NUM>. The organic layer <NUM> includes emission units <NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM>.

The organic layer <NUM> may further include a hole transport region between the first electrode <NUM> and the emission units <NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM>, and an electron transport region between the emission units <NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> and the second electrode <NUM>.

The hole transport region may have i) a single-layered structure including (e.g., consisting of) a single layer including (e.g., consisting of) a single material, ii) a single-layered structure including (e.g., consisting of) a single layer including (e.g., consisting of) a plurality of different materials, or iii) a multi-layered structure having a plurality of layers including (e.g., consisting of) a plurality of different materials.

The hole transport region may include at least one selected from a hole injection layer, a hole transport layer, an emission auxiliary layer, and an electron blocking layer.

For example, the hole transport region may have a single-layered structure including (e.g., consisting of) a single layer including (e.g., consisting of) a plurality of different materials, or a multi-layered structure having a hole injection layer/hole transport layer structure, a hole injection layer/hole transport layer/emission auxiliary layer structure, a hole injection layer/emission auxiliary layer structure, a hole transport layer/emission auxiliary layer structure, or a hole injection layer/hole transport layer/electron blocking layer structure, wherein for each structure, constituting layers are sequentially stacked from the first electrode <NUM> in this stated order, but the structure of the hole transport region is not limited thereto.

The hole transport region may include at least one selected from m-MTDATA, TDATA, <NUM>-TNATA, NPB(NPD), β-NPB, TPD, spiro-TPD, spiro-NPB, methylated NPB, TAPC, HMTPD, <NUM>,<NUM>',<NUM>"-tris(N-carbazolyl)triphenylamine (TCTA), polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA), poly(<NUM>,<NUM>-ethylenedioxythiophene)/poly(<NUM>-styrenesulfonate) (PEDOT/PSS), polyaniline/camphor sulfonic acid (PANI/CSA), polyaniline/poly(<NUM>-styrenesulfonate) (PANI/PSS), a compound represented by Formula <NUM> below, and a compound represented by Formula <NUM> below:
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>.

For example, in Formula <NUM>, R<NUM> and R<NUM> may optionally be linked to each other via a single bond, a dimethyl-methylene group, and/or a diphenyl-methylene group, and R<NUM> and R<NUM> may optionally be linked to each other via a single bond, a dimethyl-methylene group, and/or a diphenyl-methylene group.

In one or more embodiments, in Formulae <NUM> and <NUM>,.

L<NUM> to L<NUM> may each independently be selected from:.

In one or more embodiments, xa1 to xa4 may each independently be <NUM>, <NUM>, or <NUM>.

In one or more embodiments, xa5 may be <NUM>, <NUM>, <NUM>, or <NUM>.

In one or more embodiments, R<NUM> to R<NUM> and Q<NUM> may each independently be selected from: a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group; and.

In one or more embodiments, at least one selected from R<NUM> to R<NUM> in Formula <NUM> may each independently be selected from:.

In one or more embodiments, in Formula <NUM>, i) R<NUM> and R<NUM> may be linked to each other via a single bond, and/or ii) R<NUM> and R<NUM> may be linked to each other via a single bond.

In one or more embodiments, at least one of R<NUM> to R<NUM> in Formula <NUM> may each independently be selected from:.

In one or more embodiments, the compound represented by Formula <NUM> may be represented by Formula 201A below:
<CHM>.

In one or more embodiments, the compound represented by Formula <NUM> may be represented by Formula 201A(<NUM>) below, but embodiments of the present disclosure are not limited thereto:
<CHM>.

In one or more embodiments, the compound represented by Formula <NUM> may be represented by Formula 201A-<NUM> below, but embodiments of the present disclosure are not limited thereto:
<CHM>.

In one or more embodiments, the compound represented by Formula <NUM> may be represented by Formula 202A below:
<CHM>.

In one or more embodiments, the compound represented by Formula <NUM> may be represented by Formula 202A-<NUM> below:
<CHM>.

In Formulae 201A, 201A(<NUM>), 201A-<NUM>, 202A, and 202A-<NUM>,.

The hole transport region may include at least one compound selected from Compounds HT1 to HT39, but compounds to be included in the hole transport region are not limited thereto:
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>.

A thickness of the hole transport region may be in a range of about <NUM>Å to about <NUM>,<NUM>Å, for example, about <NUM>Å to about <NUM>,<NUM>Å. When the hole transport region includes at least one selected from a hole injection layer and a hole transport layer, the thickness of the hole injection layer may be in a range of about <NUM>Å to about <NUM>,<NUM>Å, for example, about <NUM>Å to about <NUM>,<NUM>Å, and the thickness of the hole transport layer may be in a range of about <NUM>Å to about <NUM>,<NUM>Å, for example, about <NUM>Å to about <NUM>,<NUM>Å. When the thicknesses of the hole transport region, the hole injection layer, and the hole transport layer are within any of these ranges, satisfactory (or suitable) hole transporting characteristics may be obtained without a substantial increase in driving voltage.

The emission auxiliary layer may increase light-emission efficiency by compensating for an optical resonance distance according to the wavelength of light emitted by an emission layer, and the electron blocking layer may block or reduce the flow of electrons from an electron transport region. The emission auxiliary layer and the electron blocking layer may each independently include any of the materials as described above.

The hole transport region may further include, in addition to the materials described above, a charge-generation material for the improvement of conductive properties.

The charge-generation material may be homogeneously or non-homogeneously dispersed in the hole transport region.

The charge-generation material may be, for example, a p-dopant.

In one or more embodiments, a LUMO energy level of the p-dopant may be about -<NUM> eV or less.

The p-dopant may include at least one selected from a quinone derivative, a metal oxide, and a cyano group-containing compound, but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, the p-dopant may include at least one selected from:.

In the organic light-emitting devices <NUM>, <NUM>, <NUM>, and <NUM>, emission units <NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> each include an emission layer, and the emission layer may have a stacked structure of two or more layers, in which the two or more layers selected from a red emission layer, green emission layer, a yellow emission layer, and a blue emission layer are in contact with each other or are separated apart from each other. In some embodiments, the emission layer may have a mixed structure of two or more materials, in which the two or more materials selected from a red light-emitting material, a green light-emitting material, a yellow light-emitting material, and a blue light-emitting material are mixed with each other in a single layer.

The emission layer may further include an electron transport (ET)-auxiliary layer formed on (e.g., on one side of) the emission layer and/or a hole transport (HT)-auxiliary layer formed under (e.g., on another side, opposite from the one side of) the emission layer. The HT-auxiliary layer is a layer that may act as the hole transport layer, the emission auxiliary layer, and/or the electron blocking layer, which are described above, and the ET-auxiliary layer is a layer that may act as a buffer layer, a hole blocking layer, an electron control layer, and/or an electron transport layer, which are described below. Materials that may be used in the HT-auxiliary layer and the ET-auxiliary layer are the same as described in connection with the hole transport region and an electron transport region described herein, respectively.

The emission layer may include a host and a dopant. The dopant may include at least one selected from a phosphorescent dopant and a fluorescent dopant.

An amount of a dopant in the emission layer may be, based on about <NUM> parts by weight of the host, in a range of about <NUM> parts by weight to about <NUM> parts by weight, but embodiments of the present disclosure are not limited thereto.

A thickness of the emission layer may be in a range of about <NUM>Å to about <NUM>,<NUM>Å, for example, about <NUM>Å to about <NUM>Å. When the thickness of the emission layer is within this range, excellent (or improved) light-emission characteristics may be obtained without a substantial increase in driving voltage.

In one or more embodiments, the host may include a compound represented by Formula <NUM> below.

Formula <NUM>     [Ar<NUM>]xb11-[(L<NUM>)xb1-R<NUM>]xb21.

For example, Ar<NUM> may be a substituted or unsubstituted C<NUM>-C<NUM> carbocyclic group or a substituted or unsubstituted C<NUM>-C<NUM> heterocyclic group, but embodiments are not limited thereto.

In one or more embodiments, Ar<NUM> in Formula <NUM> may be selected from:.

When xb11 in Formula <NUM> is <NUM> or more, two or more of Ar<NUM>(s) may be linked via a single bond.

In one or more embodiments, the compound represented by Formula <NUM> may be represented by one of Formula <NUM>-<NUM> or Formula <NUM>-<NUM>:
<CHM>
<CHM>.

In Formulae <NUM>-<NUM> and <NUM>-<NUM>,.

For example, L<NUM> to L<NUM> in Formulae <NUM>, <NUM>-<NUM>, and <NUM>-<NUM> may each independently be selected from:.

As another example, R<NUM> to R<NUM> in Formulae <NUM>, <NUM>-<NUM>, and <NUM>-<NUM> may each independently be selected from: deuterium, -F, -Cl, -Br, -I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a substituted or unsubstituted C<NUM>-C<NUM> (e.g. C<NUM>-C<NUM>) alkyl group, a substituted or unsubstituted C<NUM>-C<NUM> (e.g. C<NUM>-C<NUM>) alkenyl group, a substituted or unsubstituted C<NUM>-C<NUM> (e.g. C<NUM>-C<NUM>) alkynyl group, a substituted or unsubstituted C<NUM>-C<NUM> (e.g. C<NUM>-C<NUM>) alkoxy group, a substituted or unsubstituted C<NUM>-C<NUM> cycloalkyl group, a substituted or unsubstituted C<NUM>-C<NUM> heterocycloalkyl group, a substituted or unsubstituted C<NUM>-C<NUM> cycloalkenyl group, a substituted or unsubstituted C<NUM>-C<NUM> heterocycloalkenyl group, a substituted or unsubstituted C<NUM>-C<NUM> aryl group, a substituted or unsubstituted C<NUM>-C<NUM> aryloxy group, a substituted or unsubstituted C<NUM>-C<NUM> arylthio group, a substituted or unsubstituted C<NUM>-C<NUM> heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, -Si(Q<NUM>)(Q<NUM>)(Q<NUM>), -N(Q<NUM>)(Q<NUM>), - B(Q<NUM>)(Q<NUM>), -C(=O)(Q<NUM>), -S(=O)<NUM>(Q<NUM>), and -P(=O)(Q<NUM>)(Q<NUM>), but embodiments are not limited thereto.

In one or more embodiments, R<NUM> to R<NUM> in Formulae <NUM>, <NUM>-<NUM>, and <NUM>-<NUM> may each independently be selected from:.

In one or more embodiments, the host may include an alkaline earth-metal complex. For example, the host may include a complex selected from a Be complex (for example, Compound H55), a Mg complex, and a Zn complex. For example, the host may be selected from a Be complex (for example, Compound H55), an Mg complex, and/or a Zn complex.

The host may include at least one selected from <NUM>,<NUM>-di(<NUM>-naphthyl)anthracene (ADN), <NUM>-methyl-<NUM>,<NUM>-bis(naphthalen-<NUM>-yl)anthracene (MADN), <NUM>,<NUM>-di-(<NUM>-naphthyl)-<NUM>-t-butyl-anthracene (TBADN), <NUM>,<NUM>'-bis(N-carbazolyl)-<NUM>,<NUM>'-biphenyl (CBP), <NUM>,<NUM>-di-<NUM>-carbazolylbenzene (mCP), <NUM>,<NUM>,<NUM>-tri(carbazol-<NUM>-yl)benzene (TCP), and Compounds H1 to H55, but embodiments of the present disclosure are not limited thereto:
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>.

The phosphorescent dopant may include an organometallic complex represented by Formula <NUM> below:.

In one or more embodiments, A<NUM> and A<NUM> in Formula <NUM> may each independently be selected from a benzene group, a naphthalene group, a fluorene group, a spiro-bifluorene group, an indene group, a pyrrole group, a thiophene group, a furan group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a quinoxaline group, a quinazoline group, a carbazole group, a benzimidazole group, a benzofuran group, a benzothiophene group, an isobenzothiophene group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a dibenzofuran group, and a dibenzothiophene group.

In one or more embodiments, in Formula <NUM>, i) X<NUM> may be nitrogen, and X<NUM> may be carbon, or ii) each of X<NUM> and X<NUM> may be nitrogen.

In one or more embodiments, R<NUM> and R<NUM> in Formula <NUM> may each independently be selected from:.

In one or more embodiments, when xc1 in Formula <NUM> is <NUM> or more, two A<NUM>(s) in two or more of L<NUM>(s) may optionally be linked to each other via X<NUM>, which is a linking group, or two A<NUM>(s) may optionally be linked to each other via X<NUM>, which is a linking group (see e.g., Compounds PD1 to PD4 and PD7). X<NUM> and X<NUM> may each independently be a single bond, *-O-*', *-S-*', *-C(=O)-*', *-N(Q<NUM>)-*', *-C(Q<NUM>)(Q<NUM>)-*', or *-C(Q<NUM>)=C(Q<NUM>)-*' (wherein Q<NUM> and Q<NUM> may each independently be hydrogen, deuterium, a C<NUM>-C<NUM> alkyl group, a C<NUM>-C<NUM> alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group), but embodiments of the present disclosure are not limited thereto.

L<NUM> in Formula <NUM> may be a monovalent, divalent, or trivalent organic ligand. For example, L<NUM> may be selected from halogen, diketone (for example, acetylacetonate), carboxylic acid (for example, picolinate), -C(=O), isonitrile, -CN, and phosphorus (for example, phosphine and/or phosphite), but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, the phosphorescent dopant may be selected from, for example, Compounds PD1 to PD25, but embodiments of the present disclosure are not limited thereto:
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>.

The fluorescent dopant may include an arylamine compound or a styrylamine compound.

The fluorescent dopant may include a compound represented by Formula <NUM> below.

In one or more embodiments, L<NUM> to L<NUM> in Formula <NUM> may each independently be selected from:.

In one or more embodiments, xd4 in Formula <NUM> may be <NUM>, but embodiments of the present disclosure are not limited thereto.

For example, the fluorescent dopant may be selected from Compounds FD1 to FD22:
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>.

In one or more embodiments, the fluorescent dopant may be selected from the following compounds, but embodiments of the present disclosure are not limited thereto. <CHM>
<CHM>.

The electron transport region may have i) a single-layered structure including (e.g., consisting of) a single layer including (e.g., consisting of) a single material, ii) a single-layered structure including (e.g., consisting of) a single layer including (e.g., consisting of) a plurality of different materials, or iii) a multi-layered structure having a plurality of layers including (e.g., consisting of) a plurality of different materials.

The electron transport region may include at least one selected from a buffer layer, a hole blocking layer, an electron control layer, an electron transport layer, and an electron injection layer, but embodiments of the present disclosure are not limited thereto.

For example, the electron transport region may have an electron transport layer/electron injection layer structure, a hole blocking layer/electron transport layer/electron injection layer structure, an electron control layer/electron transport layer/electron injection layer structure, or a buffer layer/electron transport layer/electron injection layer structure, wherein for each structure, constituting layers are sequentially stacked from an emission layer. However, embodiments of the structure of the electron transport region are not limited thereto.

The electron transport region (for example, a buffer layer, a hole blocking layer, an electron control layer, and/or an electron transport layer in the electron transport region) may include a metal-free compound containing at least one π electron-deficient nitrogen-containing ring.

The "π electron-deficient nitrogen-containing ring" indicates a C<NUM>-C<NUM> (e.g. a C<NUM>-C<NUM>) heterocyclic group having at least one *-N=*' moiety as a ring-forming moiety.

For example, the "π electron-depleted nitrogen-containing ring" may be i) a <NUM>-membered to <NUM>-membered heteromonocyclic group having at least one *-N=*' moiety, ii) a heteropolycyclic group in which two or more <NUM>-membered to <NUM>-membered heteromonocyclic groups, each having at least one *-N=*' moiety, are condensed with each other, or iii) a heteropolycyclic group in which at least one of <NUM>-membered to <NUM>-membered heteromonocyclic groups, each having at least one *-N=*' moiety, is condensed with at least one C<NUM>-C<NUM> (e.g. a C<NUM>-C<NUM>) carbocyclic group.

Examples of the π electron-deficient nitrogen-containing ring include an imidazole ring, a pyrazole ring, a thiazole ring, an isothiazole ring, an oxazole ring, an isoxazole ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, an indazole ring, a purine ring, a quinoline ring, an isoquinoline ring, a benzoquinoline ring, a phthalazine ring, a naphthyridine ring, a quinoxaline ring, a quinazoline ring, a cinnoline ring, a phenanthridine ring, an acridine ring, a phenanthroline ring, a phenazine ring, a benzimidazole ring, an isobenzothiazole ring, a benzoxazole ring, an isobenzoxazole ring, a triazole ring, a tetrazole ring, an oxadiazole ring, a triazine ring, a thiadiazole ring, an imidazopyridine ring, an imidazopyrimidine ring, and an azacarbazole ring, but are not limited thereto.

For example, the electron transport region may include a compound represented by Formula <NUM> below:.

In one or more embodiments, at least one of Ar<NUM>(s) in the number of xe11 and R<NUM>(s) in the number of xe21 may include the π electron-deficient nitrogen-containing ring.

In one or more embodiments, ring Ar<NUM> in Formula <NUM> may be selected from:.

When xe11 in Formula <NUM> is <NUM> or more, two or more of Ar<NUM>(s) may be linked to each other via a single bond.

In one or more embodiments, Ar<NUM> in Formula <NUM> may be an anthracene group.

In one or more embodiments, the compound represented by Formula <NUM> may be represented by Formula <NUM>-<NUM>:
<CHM>.

For example, L<NUM> and L<NUM> to L<NUM> in Formulae <NUM> and <NUM>-<NUM> may each independently be selected from: a substituted or unsubstituted C<NUM>-C<NUM> cycloalkylene group, a substituted or unsubstituted C<NUM>-C<NUM> heterocycloalkylene group, a substituted or unsubstituted C<NUM>-C<NUM> cycloalkenylene group, a substituted or unsubstituted C<NUM>-C<NUM> heterocycloalkenylene group, a substituted or unsubstituted C<NUM>-C<NUM> arylene group, a substituted or unsubstituted C<NUM>-C<NUM> heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group, but embodiments are not limited thereto.

In one or more embodiments, L<NUM> and L<NUM> to L<NUM> in Formulae <NUM> and <NUM>-<NUM> may each independently be selected from:.

In one or more embodiments, xe1 and xe611 to xe613 in Formulae <NUM> and <NUM>-<NUM> may each independently be <NUM>, <NUM>, or <NUM>.

For example, R<NUM> and R<NUM> to R<NUM> in Formulae <NUM> and <NUM>-<NUM> may each independently be selected from: a substituted or unsubstituted C<NUM>-C<NUM> cycloalkyl group, a substituted or unsubstituted C<NUM>-C<NUM> heterocycloalkyl group, a substituted or unsubstituted C<NUM>-C<NUM> cycloalkenyl group, a substituted or unsubstituted C<NUM>-C<NUM> heterocycloalkenyl group, a substituted or unsubstituted C<NUM>-C<NUM> aryl group, a substituted or unsubstituted C<NUM>-C<NUM> aryloxy group, a substituted or unsubstituted C<NUM>-C<NUM> arylthio group, a substituted or unsubstituted C<NUM>-C<NUM> heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, - Si(Q<NUM>)(Q<NUM>)(Q<NUM>), -C(=O)(Q<NUM>), -S(=O)<NUM>(Q<NUM>), and -P(=O)(Q<NUM>)(Q<NUM>).

In one or more embodiments, R<NUM> and R<NUM> to R<NUM> in Formulae <NUM> and <NUM>-<NUM> may each independently be selected from:.

The electron transport region may include at least one compound selected from Compounds ET1 to ET36, but embodiments of the present disclosure are not limited thereto:
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>.

In one or more embodiments, the electron transport region may include at least one compound selected from <NUM>,<NUM>-dimethyl-<NUM>,<NUM>-diphenyl-<NUM>,<NUM>-phenanthroline (BCP), <NUM>,<NUM>-diphenyl-<NUM>,<NUM>-phenanthroline (Bphen), Alq<NUM>, BAlq, <NUM>-(biphenyl-<NUM>-yl)-<NUM>-(<NUM>-tert-butylphenyl)-<NUM>-phenyl-<NUM>-<NUM>,<NUM>,<NUM>-triazole (TAZ), and NTAZ. <CHM>
<CHM>.

Thicknesses of the buffer layer, the hole blocking layer, and the electron control layer may each independently be in a range of about <NUM>Å to about <NUM>,<NUM>Å, for example, about <NUM>Å to about <NUM>Å. When the thicknesses of the buffer layer, the hole blocking layer, and the electron control layer are each independently within any of these ranges, excellent (or improved) hole blocking characteristics and/or excellent (or improved) electron control characteristics may be obtained without a substantial increase in driving voltage.

A thickness of the electron transport layer may be in a range of about <NUM>Å to about <NUM>,<NUM>Å, for example, about <NUM>Å to about <NUM>Å. When the thickness of the electron transport layer is within the range described above, the electron transport layer may have satisfactory (or suitable) electron transport characteristics without a substantial increase in driving voltage.

The electron transport region (for example, the electron transport layer in the electron transport region) may further include, in addition to the materials described above, a metal-containing material.

The metal-containing material may include at least one selected from an alkali metal complex and an alkaline earth-metal complex. The alkali metal complex may include a metal ion selected from a Li ion, a Na ion, a K ion, a Rb ion, and a Cs ion, and the alkaline earth-metal complex may include a metal ion selected from a Be ion, a Mg ion, a Ca ion, a Sr ion, and a Ba ion. A ligand coordinated with the metal ion of the alkali metal complex or the alkaline earth-metal complex may be selected from a hydroxy quinoline, a hydroxy isoquinoline, a hydroxy benzoquinoline, a hydroxy acridine, a hydroxy phenanthridine, a hydroxy phenyloxazole, a hydroxy phenylthiazole, a hydroxy diphenyloxadiazole, a hydroxy diphenylthiadiazole, a hydroxy phenylpyridine, a hydroxy phenylbenzimidazole, a hydroxy phenylbenzothiazole, a bipyridine, a phenanthroline, and a cyclopentadiene, but embodiments of the present disclosure are not limited thereto.

For example, the metal-containing material may include a Li complex. The Li complex may include, for example, Compound ET-D1 (lithium quinolate, LiQ) and/or Compound ET-D2:
<CHM>.

The electron transport region may include an electron injection layer that facilitates electron injection from the second electrode <NUM>. The electron injection layer may directly contact the second electrode <NUM>.

The electron injection layer may have i) a single-layered structure including (e.g., consisting of) a single layer including (e.g., consisting of) a single material, ii) a single-layered structure including (e.g., consisting of) a single layer including (e.g., consisting of) a plurality of different materials, or iii) a multi-layered structure having a plurality of layers including (e.g., consisting of) a plurality of different materials.

The electron injection layer may include an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal compound, an alkaline earth-metal compound, a rare earth metal compound, an alkali metal complex, an alkaline earth-metal complex, a rare earth metal complex, or any combination thereof.

The alkali metal may be selected from Li, Na, K, Rb, and Cs. In one or more embodiments, the alkali metal may be Li, Na, or Cs. In one or more embodiments, the alkali metal may be Li or Cs, but embodiments of the present disclosure are not limited thereto.

The alkaline earth metal may be selected from Mg, Ca, Sr, and Ba.

The rare earth metal may be selected from Sc, Y, Ce, Yb, Gd, and Tb.

The alkali metal compound, the alkaline earth-metal compound, and the rare earth metal compound may be selected from oxides and halides (for example, fluorides, chlorides, bromides, and/or iodides) of the alkali metal, the alkaline earth metal, and the rare earth metal, respectively.

The alkali metal compound may be selected from alkali metal oxides (such as Li<NUM>O, Cs<NUM>O, and/or K<NUM>O), and alkali metal halides (such as LiF, NaF, CsF, KF, Lil, Nal, CsI, KI, and/or Rbl). In one or more embodiments, the alkali metal compound may be selected from LiF, Li<NUM>O, NaF, Lil, Nal, CsI, and KI, but embodiments of the present disclosure are not limited thereto.

The alkaline earth-metal compound may be selected from alkaline earth-metal oxides, such as BaO, SrO, CaO, BaxSr<NUM>-xO (<NUM><x<<NUM>), and/or BaxCa<NUM>-xO (<NUM><x<<NUM>). In one or more embodiments, the alkaline earth-metal compound may be selected from BaO, SrO, and CaO, but embodiments of the present disclosure are not limited thereto.

The rare earth metal compound may be selected from YbF<NUM>, ScF<NUM>, ScO<NUM>, Sc<NUM>O<NUM>, Y<NUM>O<NUM>, Ce<NUM>O<NUM>, GdF<NUM>, and TbF<NUM>. In one or more embodiments, the rare earth metal compound may be selected from YbF<NUM>, ScF<NUM>, TbF<NUM>, Ybl<NUM>, SCl<NUM>, and Tbl<NUM>, but embodiments of the present disclosure are not limited thereto.

The alkali metal complex, the alkaline earth-metal complex, and the rare earth metal complex may include an ion of alkali metal, alkaline earth metal, and rare earth metal as described above, and a ligand coordinated with a metal ion of the alkali metal complex, the alkaline earth-metal complex, or the rare earth metal complex may be selected from hydroxy quinoline, hydroxy isoquinoline, hydroxy benzoquinoline, hydroxy acridine, hydroxy phenanthridine, hydroxy phenyloxazole, hydroxy phenylthiazole, hydroxy diphenyloxadiazole, hydroxy diphenylthiadiazole, hydroxy phenylpyridine, hydroxy phenylbenzimidazole, hydroxy phenylbenzothiazole, bipyridine, phenanthroline, and cyclopentadiene, but embodiments of the present disclosure are not limited thereto.

The electron injection layer may include (e.g., may consist of) an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal compound, an alkaline earth-metal compound, a rare earth metal compound, an alkali metal complex, an alkaline earth-metal complex, a rare earth metal complex, or any combination thereof, as described above. In one or more embodiments, the electron injection layer may further include an organic material. When the electron injection layer further includes an organic material, an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal compound, an alkaline earth-metal compound, a rare earth metal compound, an alkali metal complex, an alkaline earth-metal complex, a rare earth metal complex, or any combination thereof may be homogeneously or non-homogeneously dispersed in a matrix including the organic material.

A thickness of the electron injection layer may be in a range of about <NUM>Å to about <NUM>Å, for example, about <NUM>Å to about <NUM>Å. When the thickness of the electron injection layer is within the range described above, the electron injection layer may have satisfactory (or suitable) electron injection characteristics without a substantial increase in driving voltage.

The second electrode <NUM> is located on the organic layer <NUM> described above. The second electrode <NUM> may be a cathode, which is an electron injection electrode, and in this regard, a material for forming the second electrode <NUM> may be selected from a metal, an alloy, an electrically conductive compound, and combinations thereof, which have a relatively low work function.

The second electrode <NUM> may include at least one selected from lithium (Li), silver (Ag), magnesium (Mg), aluminium (Al), aluminium-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), ITO, and IZO, but embodiments of the present disclosure are not limited thereto. The second electrode <NUM> may be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode.

The second electrode <NUM> may have a single-layered structure or a multi-layered structure including two or more layers.

Meanwhile, the organic light-emitting devices <NUM>, <NUM>, <NUM>, and <NUM> may each further include at least one selected from a first capping layer located under the first electrode and a second capping layer located on the second electrode.

Light generated in an emission layer of the organic layer <NUM> of each of the organic light-emitting devices <NUM>, <NUM>, <NUM>, and <NUM> may be extracted toward the outside through the first electrode <NUM> and the first capping layer, each of which may be a semi-transmissive electrode or a transmissive electrode, and/or light generated in an emission layer of the organic layer <NUM> of each of the organic light-emitting devices <NUM>, <NUM>, <NUM>, and <NUM> may be extracted toward the outside through the second electrode <NUM> and the second capping layer, each of which may be a semi-transmissive electrode or a transmissive electrode.

The first capping layer and the second capping layer may increase external luminescence efficiency according to the principle of constructive interference.

The first capping layer and the second capping layer may each independently be an organic capping layer including (e.g., consisting of) an organic material, an inorganic capping layer including (e.g., consisting of) an inorganic material, or a composite capping layer including an organic material and an inorganic material.

At least one selected from the first capping layer and the second capping layer may each independently include at least one material selected from carbocyclic compounds, heterocyclic compounds, amine-based compounds, porphyrine derivatives, phthalocyanine derivatives, naphthalocyanine derivatives, alkali metal complexes, and alkaline earth-metal complexes. The carbocyclic compound, the heterocyclic compound, and the amine-based compound may each independently be optionally substituted with a substituent containing at least one element selected from O, N, S, Se, Si, F, Cl, Br, and I. In one or more embodiments, at least one selected from the first capping layer and the second capping layer may each independently include an amine-based compound.

In one or more embodiments, at least one selected from the first capping layer and the second capping layer may each independently include the compound represented by Formula <NUM> or the compound represented by Formula <NUM>.

In one or more embodiments, at least one selected from the first capping layer and the second capping layer may each independently include a compound selected from Compounds HT28 to HT33 and Compounds CP1 to CP5, but embodiments of the present disclosure are not limited thereto:
<CHM>
<CHM>.

Hereinbefore, the organic light-emitting device according to an embodiment has been described in connection with <FIG>. However, embodiments of the present disclosure are not limited thereto.

<FIG> is a cross-sectional view showing a light-emitting apparatus according to an embodiment of the present disclosure.

The light-emitting apparatus of <FIG> includes a substrate <NUM>, a thin-film transistor (TFT), a light-emitting device, and an encapsulation portion <NUM> that seals light-emitting device.

The substrate <NUM> may be a flexible substrate, a glass substrate, or a metal substrate. A buffer layer <NUM> may be located on the substrate <NUM>. The buffer layer <NUM> prevents or reduces the penetration of impurities through the substrate <NUM> and may provide a flat surface on the substrate <NUM>.

A TFT may be located on the buffer layer <NUM>. The TFT may include an activation layer (e.g., an active layer) <NUM>, a gate electrode <NUM>, a source electrode <NUM>, and a drain electrode <NUM>.

The activation layer <NUM> may include an inorganic semiconductor such as silicon or polysilicon, an organic semiconductor, or an oxide semiconductor, and may include a source region, a drain region and a channel region.

A gate insulating film <NUM> for insulating the activation layer <NUM> from the gate electrode <NUM> may be located on the activation layer <NUM>, and the gate electrode <NUM> may be located on the gate insulating film <NUM>.

An interlayer insulating film <NUM> may be located on the gate electrode <NUM>. The interlayer insulating film <NUM> may be located between the gate electrode <NUM> and the source electrode <NUM> to insulate the gate electrode <NUM> from the source electrode <NUM> and between the gate electrode <NUM> and the drain electrode <NUM> to insulate the gate electrode <NUM> from the drain electrode <NUM>.

The source electrode <NUM> and the drain electrode <NUM> may be located on the interlayer insulating film <NUM>. The interlayer insulating film <NUM> and the gate insulating film <NUM> may be formed to expose the source region and the drain region of the activation layer <NUM>, and the source electrode <NUM> and the drain electrode <NUM> may be located to be in contact with the exposed portions of the source region and the drain region of the activation layer <NUM>.

The TFT may be electrically connected to the light-emitting device to drive the light-emitting device, and may be covered by a passivation layer <NUM>. The passivation layer <NUM> may include an inorganic insulating film, an organic insulating film, or a combination thereof. The light-emitting device may be provided on the passivation layer <NUM>. The light-emitting device includes the first electrode <NUM>, the organic layer <NUM>, and the second electrode <NUM>.

The first electrode <NUM> may be located on the passivation layer <NUM>. The passivation layer <NUM> does not completely cover the drain electrode <NUM> and exposes a portion of the drain electrode <NUM>, and the first electrode <NUM> may be connected to the exposed portion of the drain electrode <NUM>.

A pixel defining layer <NUM> including an insulating material may be located on the first electrode <NUM>. The pixel defining layer <NUM> may expose a certain region of the first electrode <NUM>, and the organic layer <NUM> may be formed in the exposed region of the first electrode <NUM>. The pixel defining layer <NUM> may be a polyimide-based organic film and/or a polyacryl-based organic film. In an embodiment, at least one or more portions or layers of the organic layer <NUM> may extend beyond the upper portion of the pixel defining layer <NUM> and may thus be located in the form of a common layer.

The second electrode <NUM> may be located on the organic layer <NUM>, and a capping layer <NUM> may be additionally formed on the second electrode <NUM>. The capping layer <NUM> may be formed to cover the second electrode <NUM>.

The encapsulation portion <NUM> may be located on the capping layer <NUM>. The encapsulation portion <NUM> may be located on a light-emitting device and protects the light-emitting device from moisture or oxygen. The encapsulation portion <NUM> may include: an inorganic film including silicon nitride (SiNx), silicon oxide (SiOx), indium tin oxide, indium zinc oxide, or a combination thereof; an organic film including polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, polyethylene sulfonate, polyoxymethylene, polyarylate, hexamethyldisiloxane, an acrylic resin (for example, polymethyl methacrylate and/or polyacrylic acid), an epoxy-based resin (for example, aliphatic glycidyl ether (AGE), or a combination thereof; or a combination of an inorganic film and an organic film.

Layers constituting the hole transport region, the emission layer, and layers constituting the electron transport region may each independently be formed in a certain region by using one or more suitable methods selected from vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) deposition, ink-jet printing, laser-printing, and laser-induced thermal imaging.

When any of the layers constituting the hole transport region, the emission layer, and the electron transport region are formed by vacuum deposition, the deposition may be performed at a deposition temperature of about <NUM> to about <NUM>, a vacuum degree of about <NUM>-<NUM> torr to about <NUM>-<NUM> torr, and a deposition speed of about <NUM>Å/sec to about <NUM>Å/sec by taking into account a material to be included in a layer to be formed and the structure of a layer to be formed.

When any of the layers constituting the hole transport region, the emission layer, and the electron transport region are formed by spin coating, the spin coating may be performed at a coating speed of about <NUM>,<NUM> rpm to about <NUM>,<NUM> rpm and at a heat treatment temperature of about <NUM> to <NUM> by taking into account a material to be included in a layer to be formed and the structure of a layer to be formed.

The term "C<NUM>-C<NUM> alkyl group" as used herein refers to a linear or branched aliphatic saturated hydrocarbon monovalent group having <NUM> to <NUM> carbon atoms, and non-limiting examples thereof include a methyl group, an ethyl group, a propyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an isoamyl group, and a hexyl group. The term "C<NUM>-C<NUM> alkylene group" as used herein refers to a divalent group having the same structure as the C<NUM>-C<NUM> alkyl group. Corresponding definitions apply to other ranges given for the number of carbon atoms in an alkyl/alkylene group.

The term "C<NUM>-C<NUM> alkenyl group" as used herein refers to a hydrocarbon group having at least one carbon-carbon double bond in the middle and/or at either terminus of the C<NUM>-C<NUM> alkyl group, and non-limiting examples thereof include an ethenyl group, a propenyl group, and a butenyl group. The term "C<NUM>-C<NUM> alkenylene group" as used herein refers to a divalent group having the same structure as the C<NUM>-C<NUM> alkenyl group. Corresponding definitions apply to other ranges given for the number of carbon atoms in an alkenyl/alkenylene group.

The term "C<NUM>-C<NUM> alkynyl group" as used herein refers to a hydrocarbon group having at least one carbon-carbon triple bond in the middle and/or at either terminus of the C<NUM>-C<NUM> alkyl group, and non-limiting examples thereof include an ethynyl group, and a propynyl group. The term "C<NUM>-C<NUM> alkynylene group" as used herein refers to a divalent group having the same structure as the C<NUM>-C<NUM> alkynyl group. Corresponding definitions apply to other ranges given for the number of carbon atoms in an alkynyl/alkynylene group.

The term "C<NUM>-C<NUM> alkoxy group" as used herein refers to a monovalent group represented by -OA<NUM> (wherein A<NUM> is the C<NUM>-C<NUM> alkyl group), and non-limiting examples thereof include a methoxy group, an ethoxy group, and an isopropyloxy group. Corresponding definitions apply to other ranges given for the number of carbon atoms in an alkoxy group.

The term "C<NUM>-C<NUM> cycloalkyl group" as used herein refers to a monovalent saturated hydrocarbon monocyclic group having <NUM> to <NUM> carbon atoms, and non-limiting examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group. The term "C<NUM>-C<NUM> cycloalkylene group" as used herein refers to a divalent group having the same structure as the C<NUM>-C<NUM> cycloalkyl group.

The term "C<NUM>-C<NUM> heterocycloalkyl group" as used herein refers to a monovalent monocyclic group having at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom and <NUM> to <NUM> carbon atoms as the remaining ring-forming atoms, and non-limiting examples thereof include a <NUM>,<NUM>,<NUM>,<NUM>-oxatriazolidinyl group, a tetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term "C<NUM>-C<NUM> heterocycloalkylene group" as used herein refers to a divalent group having the same structure as the C<NUM>-C<NUM> heterocycloalkyl group.

The term "C<NUM>-C<NUM> cycloalkenyl group" used herein refers to a monovalent monocyclic group that has <NUM> to <NUM> carbon atoms and at least one carbon-carbon double bond in the ring thereof and no aromaticity, and non-limiting examples thereof include a cyclopentenyl group, a cyclohexenyl group, and a cycloheptenyl group. The term "C<NUM>-C<NUM> cycloalkenylene group" as used herein refers to a divalent group having the same structure as the C<NUM>-C<NUM> cycloalkenyl group.

The term "C<NUM>-C<NUM> heterocycloalkenyl group" as used herein refers to a monovalent monocyclic group that has at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom, <NUM> to <NUM> carbon atoms as the remaining ring-forming atoms, and at least one carbon-carbon double bond in its ring. Non-limiting examples of the C<NUM>-C<NUM> heterocycloalkenyl group include a <NUM>,<NUM>-dihydro-<NUM>,<NUM>,<NUM>,<NUM>-oxatriazolyl group, a <NUM>,<NUM>-dihydrofuranyl group, and a <NUM>,<NUM>-dihydrothiophenyl group. The term "C<NUM>-C<NUM> heterocycloalkenylene group" as used herein refers to a divalent group having the same structure as the C<NUM>-C<NUM> heterocycloalkenyl group.

The term "C<NUM>-C<NUM> aryl group" as used herein refers to a monovalent group having a carbocyclic aromatic system having <NUM> to <NUM> carbon atoms. Non-limiting examples of the C<NUM>-C<NUM> aryl group include a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, and a chrysenyl group. The term "C<NUM>-C<NUM> arylene group" used herein refers to a divalent group having the same structure as the C<NUM>-C<NUM> aryl group. When the C<NUM>-C<NUM> aryl group and the C<NUM>-C<NUM> arylene group each independently include two or more rings, the respective two or more rings may be fused to each other. Corresponding definitions apply to other ranges given for the number of carbon atoms in an aryl/arylene group.

The term "C<NUM>-C<NUM> heteroaryl group" as used herein refers to a monovalent group having a heterocyclic aromatic system that has at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom, in addition to <NUM> to <NUM> carbon atoms. Non-limiting examples of the C<NUM>-C<NUM> heteroaryl group include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, and an isoquinolinyl group. The term "C<NUM>-C<NUM> heteroarylene group" as used herein refers to a divalent group having the same structure as the C<NUM>-C<NUM> heteroaryl group. When the C<NUM>-C<NUM> heteroaryl group and the C<NUM>-C<NUM> heteroarylene group each independently include two or more rings, the respective two or more rings may be condensed (e.g., fused) with each other. Corresponding definitions apply to other ranges given for the number of carbon atoms in an heteroaryl/heteroarylene group.

The term "C<NUM>-C<NUM> aryloxy group" as used herein refers to a monovalent group represented by -OA<NUM> (wherein A<NUM> is the C<NUM>-C<NUM> aryl group), and a C<NUM>-C<NUM> arylthio group used herein refers to a monovalent group represented by -SA<NUM> (wherein A<NUM> is the C<NUM>-C<NUM> aryl group). Corresponding definitions apply to other ranges given for the number of carbon atoms in an aryloxy group and an arylthio group.

The term "monovalent non-aromatic condensed polycyclic group" as used herein refers to a monovalent group having two or more rings condensed with each other, only carbon atoms as ring-forming atoms (e.g., <NUM> to <NUM> carbon atoms), and no aromaticity in its entire molecular structure (e.g., the molecular structure as a whole is non-aromatic). A non-limiting example of the monovalent non-aromatic condensed polycyclic group is a fluorenyl group. The term "divalent non-aromatic condensed polycyclic group" as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed polycyclic group.

The term "monovalent non-aromatic condensed heteropolycyclic group" as used herein refers to a monovalent group having two or more rings condensed to each other, at least one heteroatom selected from N, O, Si, P, and S, other than carbon atoms (e.g., <NUM> to <NUM> carbon atoms), as a ring-forming atom, and no aromaticity in its entire molecular structure (e.g., the molecular structure as a whole is non-aromatic). A non-limiting example of the monovalent non-aromatic condensed heteropolycyclic group is a carbazolyl group. The term "divalent non-aromatic condensed heteropolycyclic group" as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed heteropolycyclic group.

The term "C<NUM>-C<NUM> carbocyclic group" as used herein refers to a monocyclic or polycyclic group that includes only carbon atoms as ring-forming atoms and consists of <NUM> to <NUM> carbon atoms. The C<NUM>-C<NUM> carbocyclic group may be an aromatic carbocyclic group or a non-aromatic carbocyclic group. The C<NUM>-C<NUM> carbocyclic group may be a ring (such as benzene), a monovalent group (such as a phenyl group), or a divalent group (such as a phenylene group). In one or more embodiments, depending on the number of substituents connected to the C<NUM>-C<NUM> carbocyclic group, the C<NUM>-C<NUM> carbocyclic group may be a trivalent group or a quadrivalent group. Corresponding definitions apply to other ranges given for the number of carbon atoms in a carbocyclic group.

The term "C<NUM>-C<NUM> heterocyclic group" as used herein refers to a group having the same structure as the C<NUM>-C<NUM> carbocyclic group, except that as a ring-forming atom, at least one heteroatom selected from N, O, Si, P, and S is used in addition to carbon atoms (the number of carbon atoms may be in a range of <NUM> to <NUM>). Corresponding definitions apply to other ranges given for the number of carbon atoms in a heterocyclic group.

In the present specification, at least one substituent of the substituted C<NUM>-C<NUM> (e.g. C<NUM>-C<NUM>) carbocyclic group, the substituted C<NUM>-C<NUM> (e.g. C<NUM>-C<NUM>) heterocyclic group, the substituted C<NUM>-C<NUM> cycloalkylene group, the substituted C<NUM>-C<NUM> heterocycloalkylene group, the substituted C<NUM>-C<NUM> cycloalkenylene group, the substituted C<NUM>-C<NUM> heterocycloalkenylene group, the substituted C<NUM>-C<NUM> (e.g. C<NUM>-C<NUM>) arylene group, the substituted C<NUM>-C<NUM> (e.g. C<NUM>-C<NUM>) heteroarylene group, the substituted divalent non-aromatic condensed polycyclic group, the substituted divalent non-aromatic condensed heteropolycyclic group, the substituted C<NUM>-C<NUM> (e.g. C<NUM>-C<NUM>) alkyl group, the substituted C<NUM>-C<NUM> (e.g. C<NUM>-C<NUM>) alkenyl group, the substituted C<NUM>-C<NUM> (e.g. C<NUM>-C<NUM>) alkynyl group, the substituted C<NUM>-C<NUM> (e.g. C<NUM>-C<NUM>) alkoxy group, the substituted C<NUM>-C<NUM> cycloalkyl group, the substituted C<NUM>-C<NUM> heterocycloalkyl group, the substituted C<NUM>-C<NUM> cycloalkenyl group, the substituted C<NUM>-C<NUM> heterocycloalkenyl group, the substituted C<NUM>-C<NUM> (e.g. C<NUM>-C<NUM>) aryl group, the substituted C<NUM>-C<NUM> (e.g. C<NUM>-C<NUM>) aryloxy group, the substituted C<NUM>-C<NUM> (e.g. C<NUM>-C<NUM>) arylthio group, the substituted C<NUM>-C<NUM> (e.g. C<NUM>-C<NUM>) heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group may be selected from:.

The term "Ph" as used herein refers to a phenyl group, the term "Me" as used herein refers to a methyl group, the term "Et" as used herein refers to an ethyl group, the term "ter-Bu" or "But" as used herein refers to a tert-butyl group, and the term "OMe" as used herein refers to a methoxy group.

The term "biphenyl group" as used herein refers to "a phenyl group substituted with a phenyl group". For example, the "biphenyl group" may be "a substituted phenyl group" having a "C<NUM>-C<NUM> aryl group" as a substituent.

The term "terphenyl group" as used herein refers to "a phenyl group substituted with a biphenyl group". For example, the "terphenyl group" may be a "substituted phenyl group" having, as a substituent, a "C<NUM>-C<NUM> aryl group substituted with a C<NUM>-C<NUM> aryl group".

* and *' as used herein, unless defined otherwise, each refer to a binding site to a neighboring atom in a corresponding formula.

Hereinafter, an organic light-emitting device according to embodiments will be described in more detail with reference to Examples.

As substrates and anodes, each of a first glass substrate (in which <NUM>/cm<NUM> (100Å) ITO available from Corning, Inc. is formed), a second glass substrate (in which (1000Å) Ag is formed), and a third glass substrate (in which <NUM>/cm<NUM> (100Å) ITO available from Corning, Inc. is formed) was cut to a size of <NUM> x <NUM> x <NUM>, sonicated with isopropyl alcohol and pure water each for <NUM> minutes, and then cleaned by irradiation of ultraviolet rays and exposure to ozone for <NUM> minutes. Then, the first glass substrate to the third glass substrate were sequentially stacked to form an anode and loaded onto a vacuum deposition apparatus.

HT3 and F4-TCNQ were deposited at a weight ratio of <NUM> : <NUM> on the anode to form a hole injection layer having a thickness of <NUM>Å.

HT3 was deposited on the hole injection layer to form a hole transport layer having a thickness of <NUM>Å.

HT18 (<NUM>Å) was deposited on the hole transport layer to form a HT-auxiliary layer, and H8 and FD5 (here, an amount of FD5 is <NUM> wt%) were co-deposited thereon to form an emission layer having a thickness of <NUM>Å, thereby completing the formation of a first emission unit.

ET28 (<NUM>Å) was deposited on the first emission unit to form an ET-auxiliary layer.

ET1 and LiQ were deposited at a weight ratio of <NUM> : <NUM> on the ET-auxiliary layer to form an electron transport layer having a thickness of <NUM>Å.

ET <NUM> and Yb (here, an amount of Yb is <NUM> wt%) were co-deposited on the electron transport layer to form an n-type charge generating layer having a thickness of <NUM>Å, and F4-TCNQ (<NUM>Å) was deposited thereon to form a p-type charge generating layer, thereby completing the formation of a first charge generating layer.

HT3 (<NUM>Å) was deposited on the first charge generating layer to form a hole transport layer.

HT18 (<NUM>Å) was deposited on the hole transport layer to form a HT-auxiliary layer, and H8 and FD5 (here, an amount of FD5 is <NUM> wt%) were co-deposited thereon to form an emission layer having a thickness of <NUM>Å, thereby completing the formation of a second emission unit.

ET28 (<NUM>Å) was deposited on the second emission unit to form an ET-auxiliary layer.

Yb (<NUM>Å) was deposited on the electron transport layer to form an electron injection layer, thereby completing the formation of an electron transport region.

Ag and Mg (a weight ratio of <NUM>:<NUM>) (<NUM>Å) was deposited on the electron transport region to form a cathode, and HT28 (<NUM>Å) was deposited on the cathode to form a capping layer, thereby completing the manufacture of an organic light-emitting device.

An organic light-emitting device was manufactured in substantially the same manner as in Comparative Example <NUM>, except that a material for the p-type charge generating layer was changed to HT3 and Bi<NUM>Te<NUM> (here, an amount of Bi<NUM>Te<NUM> is <NUM> wt%), Bi<NUM>Te<NUM> (<NUM>Å) was deposited as an interlayer on the n-type charge generating layer before the p-type charge generating layer was deposited on the n-type charge generating layer, and the p-type charge generating layer (<NUM>Å) was deposited on the interlayer.

An organic light-emitting device was manufactured in substantially the same manner as in Example <NUM>, except that the amount of Bi<NUM>Te<NUM> in the p-type charge generating layer was changed to <NUM> wt%.

An organic light-emitting device was manufactured in substantially the same manner as in Example <NUM>, except that the thickness of the interlayer was changed to <NUM>Å.

An organic light-emitting device was manufactured in substantially the same manner as in Example <NUM>, except that the material for the p-type charge generating layer was changed to an alloy of Yb and Te (amount: <NUM> wt%).

An organic light-emitting device was manufactured in substantially the same manner as in Example <NUM>, except that the material for the p-type charge generating layer was changed to BiI<NUM>.

An organic light-emitting device was manufactured in substantially the same manner as in Example <NUM>, except that the material for the p-type charge generating layer was changed into KI (amount: <NUM> wt%).

The driving voltage, current density (mA/cm<NUM>) at the corresponding voltage, efficiency (Cd/A), white-color emission efficiency (Im/W), color coordinates (CIE_x, CIE_y), and efficiency (Cd/A/y) of the organic light-emitting devices manufactured according to Examples <NUM> to <NUM> and Comparative Examples <NUM> to <NUM> were measured and are shown in Table <NUM>, and changes in current density according to voltage and maximum emission wavelengths were measured and are shown in <FIG> and <FIG>, respectively.

Referring to <FIG> and <FIG> and Table <NUM>, the organic light-emitting devices manufactured according to Examples <NUM> to <NUM> may have reduced driving voltage and higher current density at the same voltage, compared to the organic light-emitting devices manufactured according to Comparative Examples <NUM> to <NUM> (e.g., with the same (low) voltage as those of the Examples), and may have color purity and emission efficiency that are greater than or equal to or not significantly lower than those of devices in the related art.

For example, referring to <FIG>, the emission wavelengths of the organic light-emitting device manufactured according to Examples <NUM> to <NUM> are not significantly different from those of devices in the related art, and thus blue light may be emitted.

As substrates and anodes, each of a first glass substrate (in which 15Ω/cm<NUM> (100Å) ITO available from Corning, Inc. is formed), a second glass substrate (in which (1000Å) Ag is formed), and a third glass substrate (in which 15Ω/cm<NUM> (100Å) ITO available from Corning, Inc. is formed) was cut to a size of <NUM> x <NUM> x <NUM>, sonicated with isopropyl alcohol and pure water each for <NUM> minutes, and then cleaned by irradiation of ultraviolet rays and exposure to ozone for <NUM> minutes. Then, the first glass substrate to the third glass substrate were sequentially stacked to form an anode and loaded onto a vacuum deposition apparatus.

HT3 was deposited on the hole injection layer to form a hole transport layer.

ET1 was deposited on the ET-auxiliary layer to form an electron transport layer having a thickness of <NUM>Å.

ET <NUM> and Yb (here, an amount of Yb is <NUM> wt%) were co-deposited on the electron transport layer to form an n-type charge generating layer having a thickness of <NUM>Å, and HT3 and PbTe (here, an amount of PbTe is <NUM> wt%) were co-deposited thereon to form a p-type charge generating layer having a thickness of <NUM>Å, thereby completing the formation of a first charge generating layer.

An organic light-emitting device was manufactured in substantially the same manner as in Example <NUM>, except that <NUM> wt% of Cul was deposited on the n-type charge generating layer to additionally form an auxiliary layer between the n-type charge generating layer and the p-type charge generating layer, the amount of Cul being based on a total weight of the p-type charge generating layer.

An organic light-emitting device was manufactured in substantially the same manner as in Example <NUM>, except that the p-type charge generating layer further included <NUM> wt% of Cul, based on a total weight of the p-type charge generating layer.

An organic light-emitting device was manufactured in substantially the same manner as in Example <NUM>, except that <NUM> wt% of Cul was deposited to form an auxiliary layer.

Electrical conductivity and changes in electrical conductivity according to temperature of the organic light-emitting devices manufactured according to Examples <NUM> to <NUM> were measured and are shown in <FIG> and <FIG>, respectively.

Referring to <FIG> and <FIG>, the organic light-emitting devices which further include Cul and manufactured according to Examples <NUM> to <NUM> have excellent electrical conductivity, compared to the organic light-emitting device manufactured according to Example <NUM>, which does not include Cul.

The organic light-emitting device may have low driving voltage, high efficiency, and long lifespan.

In addition, the terms "substantially," "about," and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent deviations in measured or calculated values that would be recognized by those of ordinary skill in the art.

Claim 1:
An organic light-emitting device (<NUM>, <NUM>, <NUM>, <NUM>) comprising:
a first electrode (<NUM>);
a second electrode (<NUM>) facing the first electrode (<NUM>);
m emission units (<NUM>) between the first electrode (<NUM>) and the second electrode (<NUM>), the m emission units (<NUM>) comprising at least one emission layer; and
m-<NUM> charge generating layers (<NUM>) between two adjacent emission units among the m emission units (<NUM>), each of the m-<NUM> charge generating layers (<NUM>) comprising an n-type charge generating layer (<NUM>') and a p-type charge generating layer (<NUM>"),
wherein m is an integer of <NUM> or more,
at least one of the m-<NUM> p-type charge generating layers (<NUM>") comprises a first inorganic material, wherein the first inorganic material is a compound comprising a post transition metal and a metalloid,
the post transition metal is at least one selected from aluminum (Al), gallium (Ga), indium (In), thallium (TI), tin (Sn), lead (Pb), flerovium (FI), bismuth (Bi), and polonium (Po),
the metalloid is at least one selected from boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te), and astatine (At), and
at least one of the m-<NUM> n-type charge generating layers (<NUM>') includes a metal.