Patent Application
20230225191
This application claims priority to and benefits of Korean Patent Application No. 10-2022-0005329 under 35 U.S.C. § 119, filed on Jan. 13, 2022, in the Korean Intellectual Property Office (KIPO), the entire contents of which are incorporated herein by reference.
Embodiments relate to a light-emitting device and an electronic apparatus including the same.
Light-emitting devices are self-emissive devices that, as compared with devices of the related art, have wide viewing angles, high contrast ratios, short response times, and excellent characteristics in terms of luminance, driving voltage, and response speed.
In a light-emitting device, a first electrode may be disposed on a substrate, and a hole transport region, an emission layer, an electron transport region, and a second electrode may be sequentially formed 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, may recombine in the emission layer to produce light.
Embodiments include a light-emitting device having improved driving voltage and lifespan.
Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments of the disclosure.
According to embodiments, a light-emitting device may include a first electrode, a second electrode facing the first electrode, and an interlayer between the first electrode and the second electrode,
wherein the interlayer may include an emission layer and a hole transport layer between the first electrode and the emission layer; the emission layer may include a first host, a second host, and a dopant; the first host may include a hole-transporting host; the second host may include an electron-transporting host or a bipolar host; the hole transport layer may include multiple hole transport layers; the hole transport layers may each include a carbazole-based compound; and highest occupied molecular orbital (HOMO) energy levels of the carbazole-based compounds respectively included in neighboring ones of the hole transport layers may be different from each other.
In an embodiment, the dopant may include a phosphorescent dopant, a thermally activated delayed fluorescence dopant, and/or a fluorescent dopant.
In an embodiment, the first electrode may be an anode, the second electrode may be a cathode, the interlayer may further include a hole transport region between the first electrode and the emission layer, and the hole transport region may include a hole injection layer, an electron blocking layer, or any combination thereof.
In an embodiment, the first electrode may be an anode, the second electrode may be a cathode, the interlayer may further include an electron transport region between the second electrode and the emission layer, and the electron transport region may include a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof.
In an embodiment, the emission layer may emit blue light.
In an embodiment, the hole transport layer may consist of a first hole transport layer and a second hole transport layer.
In an embodiment, the hole transport layer may consist of a first hole transport layer, a second hole transport layer, and a third hole transport layer.
In an embodiment, a total thickness of the hole transport layer may be in a range of about 500 Å to about 2,000 Å.
In an embodiment, the dopant may include a first dopant and a second dopant, and intersystem crossing (ISC) may occur more actively in one of the first dopant and the second dopant than emission of light.
In an embodiment, one of the first dopant and the second dopant may be a phosphorescent dopant, the other of the first dopant and the second dopant may be a fluorescent dopant, and ISC may occur more actively in the phosphorescent dopant than emission of light; or one of the first dopant and the second dopant may be a thermally activated delayed fluorescence dopant, the other of the first dopant and the second dopant may be a fluorescent dopant, and ISC may occur more actively in the thermally activated delayed fluorescence dopant than emission of light.
In an embodiment, a weight ratio of the first dopant to the second dopant may be in a range of about 1:15 to about 15:1.
In an embodiment, a weight ratio of the first host to the second host may be in a range of about 1:9 to about 9:1.
In an embodiment, the first host may be one of Compounds 1-1 to 1-22, which are explained below.
In an embodiment, the second host may be one of Compounds 2-1 to 2-29, which are explained below.
In an embodiment, the carbazole-based compound may be one of Compounds 1-1 to 1-22, which are explained below.
In an embodiment, the phosphorescent dopant may be one of Compounds 3-11 to 3-18, which are explained below.
In an embodiment, the thermally activated delayed fluorescence dopant may be one of Compounds 4-1 to 4-16, which are explained below.
In an embodiment, the fluorescent dopant may be one of Compounds 5-1 to 5-6, which are explained below.
According to embodiments, an electronic apparatus may include the light-emitting device.
In an embodiment, the electronic apparatus may further include a thin-film transistor, wherein the thin-film transistor may include a source electrode and a drain electrode, and the first electrode of the light-emitting device may be electrically connected to the source electrode or the drain electrode.
It is to be understood that the embodiments above are described in a generic and explanatory sense only and not for the purpose of limitation, and the disclosure is not limited to the embodiments described above.
The above and other aspects, features, and advantages of certain embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:
The disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments are shown. This disclosure may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.
In the drawings, the sizes, thicknesses, ratios, and dimensions of the elements may be exaggerated for ease of description and for clarity. Like numbers refer to like elements throughout.
In the description, it will be understood that when an element (or region, layer, part, etc.) is referred to as being “on”, “connected to”, or “coupled to” another element, it can be directly on, connected to, or coupled to the other element, or one or more intervening elements may be present therebetween. In a similar sense, when an element (or region, layer, part, etc.) is described as “covering” another element, it can directly cover the other element, or one or more intervening elements may be present therebetween.
In the description, when an element is “directly on,” “directly connected to,” or “directly coupled to” another element, there are no intervening elements present. For example, “directly on” may mean that two layers or two elements are disposed without an additional element such as an adhesion element therebetween.
As used herein, the expressions used in the singular such as “a,” “an,” and “the,” are intended to include the plural forms as well, unless the context clearly indicates otherwise.
In the specification and the claims, the term “and/or” is intended to include any combination of the terms “and” and “or” for the purpose of its meaning and interpretation. For example, “A and/or B” may be understood to mean “A, B, or A and B.” The terms “and” and “or” may be used in the conjunctive or disjunctive sense and may be understood to be equivalent to “and/or.”
In the specification and the claims, the term “at least one of” is intended to include the meaning of “at least one selected from the group of” for the purpose of its meaning and interpretation. For example, “at least one of A and B” may be understood to mean “A, B, or A and B.” When preceding a list of elements, the term, “at least one of,” modifies the entire list of elements and does not modify the individual elements of the list.
It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element.
Thus, a first element could be termed a second element without departing from the teachings of the disclosure. Similarly, a second element could be termed a first element, without departing from the scope of the disclosure.
The spatially relative terms “below”, “beneath”, “lower”, “above”, “upper”, or the like, may be used herein for ease of description to describe the relations between one element or component and another element or component as illustrated in the drawings. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the drawings. For example, in the case where a device illustrated in the drawing is turned over, the device positioned “below” or “beneath” another device may be placed “above” another device. Accordingly, the illustrative term “below” may include both the lower and upper positions. The device may also be oriented in other directions and thus the spatially relative terms may be interpreted differently depending on the orientations.
The terms “about” or “approximately” as used herein is inclusive of the stated value and means within an acceptable range of deviation for the recited value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with measurement of the recited quantity (i.e., the limitations of the measurement system). For example, “about” may mean within one or more standard deviations, or within +20%, 10%, or ±5% of the stated value.
It should be understood that the terms “comprises,” “comprising,” “includes,” “including,” “have,” “having,” “contains,” “containing,” and the like are intended to specify the presence of stated features, integers, steps, operations, elements, components, or combinations thereof in the disclosure, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.
Also, when an element is referred to as being “in contact” or “contacted” or the like to another element, the element may be in “electrical contact” or in “physical contact” with another element; or in “indirect contact” or in “direct contact” with another element.
Unless otherwise defined or implied herein, all terms (including technical and scientific terms) used have the same meaning as commonly understood by those skilled in the art to which this disclosure pertains. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and should not be interpreted in an ideal or excessively formal sense unless clearly defined in the specification.
A light-emitting device according to an embodiment of the disclosure may include:
a first electrode;
a second electrode facing the first electrode; and
an interlayer between the first electrode and the second electrode,
wherein the interlayer may include an emission layer and a hole transport layer between the first electrode and the emission layer,
the emission layer may include a first host, a second host, and a dopant,
the first host may include a hole-transporting host,
the second host may include an electron-transporting host or a bipolar host,
the hole transport layer may include multiple hole transport layers,
the hole transport layers may each include a carbazole-based compound, and
highest occupied molecular orbital (HOMO) energy levels of the carbazole-based compounds respectively included in neighboring ones of the hole transport layers may be different from each other.
In the light-emitting device according to an embodiment, hole injection may be controlled by using different carbazole-based compounds in the hole transport layers, and thus, excitons in the emission layer may be controlled, thereby improving the device lifespan. In this regard, the hole transport layers that are combined based on the HOMO energy levels of the carbazole-based compounds may reduce material degradation by controlling hole injection mobility, thereby improving the driving voltage and lifespan of the light-emitting device.
The hole-transporting host may be a host capable of transporting holes, and the electron-transporting host may be a host capable of transporting electrons. The bipolar host may be a host capable of transporting both holes and electrons.
In an embodiment, the dopant may include a phosphorescent dopant, a thermally activated delayed fluorescence dopant, and/or a fluorescent dopant.
For example, the dopant of the light-emitting device according to an embodiment may only include a phosphorescent dopant. For example, the dopant of the light-emitting device according to an embodiment may consist of a phosphorescent dopant and a thermally activated delayed fluorescence dopant. For example, the dopant of the light-emitting device according to an embodiment may consist of a phosphorescent dopant and a fluorescent dopant.
The fluorescent dopant may be a dopant emitting light according to a general fluorescence mechanism, rather than a dopant emitting light according to a thermally activated delayed fluorescence mechanism. As used herein, a fluorescent dopant may be distinguished from a thermally activated delayed fluorescence dopant.
In an embodiment, the first electrode may be an anode, the second electrode may be a cathode, the interlayer may further include a hole transport region located the first electrode and the emission layer, and the hole transport region may include a hole injection layer, an electron blocking layer, or any combination thereof.
In an embodiment, the first electrode may be an anode, the second electrode may be a cathode, the interlayer may further include an electron transport region between the second electrode and the emission layer, and the electron transport region may include a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof.
In an embodiment, the emission layer may emit blue light.
In an embodiment, the hole transport layers may be two layers or three layers.
In an embodiment, the hole transport layer may consist of a first hole transport layer and a second hole transport layer.
In an embodiment, the hole transport layer may consist of a first hole transport layer, a second hole transport layer, and a third hole transport layer.
Since difference in HOMO energy levels of hole transport layers may be affected by configurations of an emission layer, an electron transport layer, and the like, it may not be clearly stated that, for example, the HOMO energy levels of the hole transport layers increase toward the emission layer, or that the HOMO energy levels of the hole transport layers decrease toward the emission layer. Accordingly, for example, in case that the hole transport layer includes two hole transport layers, a HOMO energy level of a first hole transport layer and a HOMO energy level of a second hole transport layer may be controlled according to the configurations of the emission layer and the electron transport layer of the light-emitting device, so that hole injection may be controlled. This is the same in case that the hole transport layer consists of three layers including a first hole transport layer, a second hole transport layer, and a third hole transport layer.
In an embodiment, a total thickness of the hole transport layer may be in a range of about 500 Å to about 2,000 Å.
In case that the multiple hole transport layers include two layers consisting of a first hole transport layer and a second hole transport layer, a thickness of the first hole transport layer and a thickness of the second hole transport layer may each independently be in a range of about 50 Å to about 1,000 Å.
In case that the hole transport layers are three layers consisting of a first hole transport layer, a second hole transport layer, and a third hole transport layer, a thickness of the first hole transport layer may be in a range of about 20 Å to about 600 Å, a thickness of the second hole transport layer may be in a range of about 40 Å to about 800 Å, and a thickness of the third hole transport layer may be in a range of about 20 Å to about 600 Å.
In case that the thickness of the hole transport layer is within the range described above, hole mobility may be easily controlled.
In case that the hole transport layers are three layers consisting of a first hole transport layer, a second hole transport layer, and a third hole transport layer, a carbazole-based compound included in the first hole transport layer may be identical to or different from a carbazole-based compound included in the third hole transport layer.
In an embodiment, the dopant may include a first dopant and a second dopant, wherein, an intersystem crossing (ISC) may occur more actively in one of the first dopant and the second dopant than emission of light.
In an embodiment, one of the first dopant and the second dopant may be a phosphorescent dopant, the other of the first dopant and the second dopant may be a fluorescent dopant, and ISC may occur more actively in the phosphorescent dopant than emission of light; or
one of the first dopant and the second dopant may be a thermally activated delayed fluorescence dopant, the other of the first dopant and the second dopant may be a fluorescent dopant, and ISC may occur more actively in the thermally activated delayed fluorescence dopant than emission of light.
For example, ISC may occur more actively than emission of light in the phosphorescent dopant or the thermally activated delayed fluorescence dopant.
Singlet excitons generated in the host may be transferred to the fluorescent dopant by the ISC.
For example, about 20% to about 30% of the phosphorescent dopant or the thermally activated delayed fluorescence dopant may emit light, and about 80% to about 70% of the phosphorescent dopant or the thermally activated delayed fluorescence dopant may cause ISC. Singlet excitons generated in the first host, singlet excitons generated in the second host, and/or excitons generated in the first host and the second host may be transferred to the fluorescent dopant by ISC.
In an embodiment, a weight ratio of the first host to the second host may be in a range of about 1:9 to about 9:1. For example, the emission layer may include the first host and the second host at a weight ratio in a range of about 3:7 to about 7:3. In case that the weight ratio of the first host to the second host is within the ranges described above, hole transport may be in a desirable balance with electron transport.
In an embodiment, a weight ratio of the first dopant to the second dopant may be in a range of about 1:15 to about 15:1. For example, the emission layer may include the first dopant and the second dopant at a weight ratio in a range of about 1:10 to about 10:1. In case that the weight ratio of the first dopant to the second dopant is within the ranges described above, operation of emission system passing through ISC may be optimized.
In an embodiment, the carbazole-based compound may be one of Compounds 1-1 to 1-22:
The carbazole-based compounds 1-1 to 1-22 may be identical to or different from the first host.
The hosts and the dopants may be the same as described herein.
An electronic apparatus according to an embodiment of the disclosure may include the light-emitting device.
In an embodiment, the electronic apparatus may further include a thin-film transistor,
the thin-film transistor may include a source electrode and a drain electrode, and
the first electrode of the light-emitting device may be electrically connected to at least one of the source and drain electrodes of the thin-film transistor.
In an embodiment, the electronic apparatus may further include a color filter, a color conversion layer, a touch screen layer, a polarizing layer, or any combination thereof.
The term “interlayer” as used herein may be a single layer and/or multiple layers located between the first electrode and the second electrode of the light-emitting device.
[Description of
Hereinafter, the structure of the light-emitting device 10 according to an embodiment and a method of manufacturing the light-emitting device 10 will be described with reference to
[First Electrode 110]
In
The first electrode 110 may be formed by, for example, depositing or sputtering a material for forming the first electrode 110 on the substrate. In case that the first electrode 110 is an anode, the material for forming the first electrode 110 may be a high work function material that facilitates injection of holes.
The first electrode 110 may be a reflective electrode, a semi-transmissive electrode, or a transmissive electrode. In case that the first electrode 110 is a transmissive electrode, the material for forming the first electrode 110 may include indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO2), zinc oxide (ZnO), or any combination thereof. In embodiments, in case that the first electrode 110 is a semi-transmissive electrode or a reflective electrode, the material for forming the first electrode 110 may include magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), or any combination thereof.
The first electrode 110 may have a single-layered structure consisting of a single layer or a multi-layered structure including multiple layers. For example, the first electrode 110 may have a three-layered structure of ITO/Ag/ITO.
[Interlayer 130]
The interlayer 130 may be disposed on the first electrode 110. The interlayer 130 may include an emission layer.
The interlayer 130 may further include a hole transport region located between the first electrode 110 and the emission layer and an electron transport region located between the emission layer and the second electrode 150.
The interlayer 130 may further include, in addition to various organic materials, a metal-containing compound, such as an organometallic compound, an inorganic material, such as a quantum dot, and the like.
In embodiments, the interlayer 130 may include i) two or more emission layers sequentially stacked each other between the first electrode 110 and the second electrode 150 and ii) a charge generation layer located between the two or more emission layers. In case that the interlayer 130 includes the emission layers and the charge generation layer as described above, the light-emitting device 10 may be a tandem light-emitting device.
[Hole transport region in interlayer 130]
The hole transport region may have i) a single-layered structure consisting of a single layer consisting of a single material, ii) a single-layered structure consisting of a single layer consisting of multiple different materials, or iii) a multi-layered structure including multiple layers including different materials.
The hole transport region may include a hole injection layer, a hole transport layer, an emission auxiliary layer, an electron blocking layer, or any combination thereof.
For example, the hole transport region may have a multi-layered structure including 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, the layers of each structure being stacked each other sequentially from the first electrode 110.
The hole transport region may include a compound represented by Formula 201, a compound represented by Formula 202, or any combination thereof:
wherein in Formulae 201 and 202,
L201 to L204 may each independently be a C3-C60 carbocyclic group unsubstituted or substituted with at least one R10a or a C1-C60 heterocyclic group unsubstituted or substituted with at least one R10a,
L205 may be *—O—*′, *—S—*′, *—N(Q201)-*′, a C1-C20 alkylene group unsubstituted or substituted with at least one R10a, a C2-C20 alkenylene group unsubstituted or substituted with at least one R10a, a C3-C60 carbocyclic group unsubstituted or substituted with at least one R10a, or a C1-C60 heterocyclic group unsubstituted or substituted with at least one R10a,
xa1 to xa4 may each independently be an integer from 0 to 5,
xa5 may be an integer from 1 to 10,
R201 to R204 and Q201 may each independently be a C3-C60 carbocyclic group unsubstituted or substituted with at least one R10a or a C1-C60 heterocyclic group unsubstituted or substituted with at least one R10a,
R201 and R202 may optionally be linked to each other via a single bond, a C1-C5 alkylene group unsubstituted or substituted with at least one R10a, or a C2-C5 alkenylene group unsubstituted or substituted with at least one R10a to form a C8-C60 polycyclic group (for example, a carbazole group, etc.) unsubstituted or substituted with at least one R10a (for example, see Compound HT16, etc.),
R203 and R204 may optionally be linked to each other via a single bond, a C1-C5 alkylene group unsubstituted or substituted with at least one R10a, or a C2-C5 alkenylene group unsubstituted or substituted with at least one R10a to form a C8-C60 polycyclic group unsubstituted or substituted with at least one R10a, and
na1 may be an integer from 1 to 4.
For example, each of Formulae 201 and 202 may include at least one of groups represented by Formulae CY201 to CY217:
wherein in Formulae CY201 to CY217, R10b and R10c may each be the same as described in connection with R10a, ring CY201 to ring CY204 may each independently be a C3-C20 carbocyclic group or a C1-C20 heterocyclic group, and at least one hydrogen in Formulae CY201 to CY217 may be unsubstituted or substituted with R10a as described herein.
In an embodiment, ring CY201 to ring CY204 in Formulae CY201 to CY217 may each independently be a benzene group, a naphthalene group, a phenanthrene group, or an anthracene group.
In embodiments, each of Formulae 201 and 202 may include at least one of groups represented by Formulae CY201 to CY203.
In embodiments, Formula 201 may include at least one of the groups represented by Formulae CY201 to CY203 and at least one of the groups represented by Formulae CY204 to CY217.
In embodiments, in Formula 201, xa1 may be 1, R201 may be a group represented by one of Formulae CY201 to CY203, xa2 may be 0, and R202 may be a group represented by one of Formulae CY204 to CY207.
In embodiments, each of Formulae 201 and 202 may not include a group represented by one of Formulae CY201 to CY203.
In embodiments, each of Formulae 201 and 202 may not include a group represented by one of Formulae CY201 to CY203, and may include at least one of the groups represented by Formulae CY204 to CY217.
In embodiments, each of Formulae 201 and 202 may not include a group represented by one of Formulae CY201 to CY217.
For example, the hole transport region may include one of Compounds HT1 to HT46, one of Compounds 1-1 to 1-22, m-MTDATA, TDATA, 2-TNATA, NPB(NPD), β-NPB, TPD, Spiro-TPD, Spiro-NPB, methylated NPB, TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA), polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA), poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS), polyaniline/camphor sulfonic acid (PANI/CSA), polyaniline/poly(4-styrenesulfonate) (PANI/PSS), or any combination thereof:
A thickness of the hole transport region may be in a range of about 50 Å to about 10,000 Å, for example, about 100 Å to about 4,000 Å. In case that the hole transport region includes a hole injection layer, a hole transport layer, or any combination thereof, a thickness of the hole injection layer may be in a range of about 100 Å to about 9,000 Å, for example, about 100 Å to about 1,000 Å. In case that the thicknesses of the hole transport region and the hole injection layer are within the ranges described above, satisfactory 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 from the emission layer, and the electron blocking layer may block the leakage of electrons from the emission layer to the hole transport region. Materials that may be included in the hole transport region may be included in the electron-blocking layer.
[p-dopant]
The hole transport region may further include, in addition to these materials, a charge-generation material for the improvement of conductive properties. The charge-generation material may be uniformly or non-uniformly dispersed in the hole transport region (for example, in the form of a single layer consisting of a charge-generation material).
The charge-generation material may be, for example, a p-dopant.
For example, the p-dopant may have a lowest unoccupied molecular orbital (LUMO) energy level of about −3.5 eV or less.
In an embodiment, the p-dopant may include a quinone derivative, a cyano group-containing compound, a compound containing element EL1 and element EL2, or any combination thereof.
Examples of the quinone derivative may include TCNQ, F4-TCNQ, and the like.
Examples of the cyano group-containing compound may include HAT-CN and a compound represented by Formula 221:
wherein in Formula 221,
R221 to R223 may each independently be a C3-C60 carbocyclic group unsubstituted or substituted with at least one R10a or a C1-C60 heterocyclic group unsubstituted or substituted with at least one R10a, and
at least one of R221 to R223 may each independently be a C3-C60 carbocyclic group or a C1-C60 heterocyclic group, each substituted with a cyano group; —F; —Cl; —Br; —I; a C1-C20 alkyl group substituted with a cyano group, —F, —Cl, —Br, —I, or any combination thereof; or any combination thereof.
In the compound containing element EL1 and element EL2, element EL1 may be metal, metalloid, or any combination thereof, and element EL2 may be non-metal, metalloid, or any combination thereof.
Examples of the metal in element EL1 may include: an alkali metal (for example, lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), etc.); an alkaline earth metal (for example, beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), etc.); a transition metal (for example, titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), technetium (Tc), rhenium (Re), iron (Fe), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu), silver (Ag), gold (Au), etc.); a post-transition metal (for example, zinc (Zn), indium (In), tin (Sn), etc.); and a lanthanide metal (for example, lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), etc.).
Examples of the metalloid in elements EL1 and EL2 may include silicon (Si), antimony (Sb), and tellurium (Te).
Examples of the non-metal in element EL2 may include oxygen (O) and halogen (for example, F, Cl, Br, I, etc.).
For example, the compound containing element EL1 and element EL2 may include metal oxide, metal halide (for example, metal fluoride, metal chloride, metal bromide, metal iodide, etc.), metalloid halide (for example, metalloid fluoride, metalloid chloride, metalloid bromide, metalloid iodide, etc.), metal telluride, or any combination thereof.
Examples of the metal oxide of the compound may include tungsten oxide (for example, WO, W2O3, WO2, WO3, W2O5, etc.), vanadium oxide (for example, VO, V2O3, VO2, V2O5, etc.), molybdenum oxide (MoO, Mo2O3, MoO2, MoO3, Mo2O5, etc.), and rhenium oxide (for example, ReO3, etc.).
Examples of the metal halide of the compound may include alkali metal halide, alkaline earth metal halide, transition metal halide, post-transition metal halide, and lanthanide metal halide.
Examples of the alkali metal halide of the compound may include LiF, NaF, KF, RbF, CsF, LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI, RbI, and CsI.
Examples of the alkaline earth metal halide of the compound may include BeF2, MgF2, CaF2, SrF2, BaF2, BeCl2, MgCl2, CaCl2), SrCl2, BaCl2, BeBr2, MgBr2, CaBr2, SrBr2, BaBr2, Be12, Mgl2, Cal2, Sr12, and Bal2.
Examples of the transition metal halide of the compound may include titanium halide (for example, TiF4, TiCl4, TiBr4, Til4, etc.), zirconium halide (for example, ZrF4, ZrCl4, ZrBr4, Zr14, etc.), hafnium halide (for example, HfF4, HfCl4, HfBr4, Hfl4, etc.), vanadium halide (for example, VF3, VCl3, VBr3, VI3, etc.), niobium halide (for example, NbF3, NbCl3, NbBr3, NbI3, etc.), tantalum halide (for example, TaF3, TaCl3, TaBr3, TaI3, etc.), chromium halide (for example, CrF3, CrCl3, CrBr3, CrI3, etc.), molybdenum halide (for example, MoF3, MoCl3, MoBr3, MoI3, etc.), tungsten halide (for example, WF3, WCl3, WBr3, WI3, etc.), manganese halide (for example, MnF2, MnCl2, MnBr2, Mnl2, etc.), technetium halide (for example, TcF2, TcCl2, TcBr2, TcI2, etc.), rhenium halide (for example, ReF2, ReCl2, ReBr2, ReI2, etc.), iron halide (for example, FeF2, FeCl2, FeBr2, FeI2, etc.), ruthenium halide (for example, RuF2, RuCl2, RuBr2, Rul2, etc.), osmium halide (for example, OsF2, OsCl2, OsBr2, OsI2, etc.), cobalt halide (for example, CoF2, CoCl2, CoBr2, CoI2, etc.), rhodium halide (for example, RhF2, RhCl2, RhBr2, Rhl2, etc.), iridium halide (for example, IrF2, IrCl2, IrBr2, IrI2, etc.), nickel halide (for example, NiF2, NiCl2, NiBr2, NiI2, etc.), palladium halide (for example, PdF2, PdCl2, PdBr2, PdI2, etc.), platinum halide (for example, PtF2, PtCl2, PtBr2, PtI2, etc.), copper halide (for example, CuF, CuCl, CuBr, CuI, etc.), silver halide (for example, AgF, AgCl, AgBr, AgI, etc.), and gold halide (for example, AuF, AuCl, AuBr, AuI, etc.).
Examples of the post-transition metal halide of the compound may include zinc halide (for example, ZnF2, ZnCl2, ZnBr2, ZnI2, etc.), indium halide (for example, InI3, etc.), and tin halide (for example, SnI2, etc.).
Examples of the lanthanide metal halide of the compound may include YbF, YbF2, YbF3, SmF3, YbCl, YbCl2, YbCl3, SmCl3, YbBr, YbBr2, YbBr3, SmBr3, YbI, YbI2, YbI3, and SmI3.
Examples of the metalloid halide of the compound may include antimony halide (for example, SbCl5, etc.).
Examples of the metal telluride of the compound may include alkali metal telluride (for example, Li2Te, Na2Te, K2Te, Rb2Te, Cs2Te, etc.), alkaline earth metal telluride (for example, BeTe, MgTe, CaTe, SrTe, BaTe, etc.), transition metal telluride (for example, TiTe2, ZrTe2, HfTe2, V2Te3, Nb2Te3, Ta2Te3, Cr2Te3, Mo2Te3, W2Te3, MnTe, TcTe, ReTe, FeTe, RuTe, OsTe, CoTe, RhTe, IrTe, NiTe, PdTe, PtTe, Cu2Te, CuTe, Ag2Te, AgTe, Au2Te, etc.), post-transition metal telluride (for example, ZnTe, etc.), and lanthanide metal telluride (for example, LaTe, CeTe, PrTe, NdTe, PmTe, EuTe, GdTe, TbTe, DyTe, HoTe, ErTe, TmTe, YbTe, LuTe, etc.).
[Emission Layer in Interlayer 130]
In case that the light-emitting device 10 is a full-color light-emitting device, the emission layer may be patterned into a red emission layer, a green emission layer, and/or a blue emission layer, according to a subpixel. In embodiments, the emission layer may have a stacked structure of two or more layers of a red emission layer, a green emission layer, and a blue emission layer, in which the two or more layers contact each other or are separated from each other to emit white light. In embodiments, the emission layer may have a structure in which two or more materials of a red light-emitting material, a green light-emitting material, and a blue light-emitting material are mixed with each other in a single layer, and thus emit white light.
The emission layer may include a host and a dopant. The dopant may include a phosphorescent dopant, a thermally activated delayed fluorescence dopant, a fluorescent dopant, or any combination thereof.
An amount of the dopant in the emission layer may be in a range of about 0.01 part by weight to about 15 parts by weight based on 100 parts by weight of the host.
For example, a total amount of the phosphorescent dopant and the fluorescent dopant or a total amount of the thermally activated delayed fluorescence dopant and the fluorescent dopant in the emission layer may be in a range of about 0.01 part by weight to about 15 parts by weight, based on 100 parts by weight of the first host and the second host.
In embodiments, the emission layer may include a quantum dot.
In embodiments, the emission layer may include a delayed fluorescence material. The delayed fluorescence material may act as a host or a dopant in the emission layer.
A thickness of the emission layer may be in a range of about 100 Å to about 1,000 Å, for example, about 200 Å to about 600 Å. In case that the thickness of the emission layer is within the range described above, excellent light-emission characteristics may be obtained without a substantial increase in driving voltage.
[Host]
The hole-transporting host may be a compound having strong hole properties.
The expression “a compound having strong hole properties” may be a compound that may readily accept holes, and such properties may be obtained by including a hole-receiving moiety (also, referred to as a hole-transporting moiety).
Such a hole-receiving moiety may include, for example, a rr-electron-rich heteroaromatic compound (for example, a carbazole derivative or an indole derivative), or an aromatic amine compound.
The electron-transporting host may be a compound having strong electron properties. The expression “a compound having strong electron properties” may be a compound that may readily accept electrons, and such properties may be obtained by including an electron-receiving moiety (also, referred to as an electron-transporting moiety).
Such an electron-receiving moiety may include, for example, a π electron-deficient heteroaromatic compound. For example, the electron-receiving may include a nitrogen-containing heteroaromatic compound.
In case that a compound includes only a hole-transporting moiety or only an electron-transporting moiety, it is clear whether the nature of the compound has hole-transporting properties or electron-transporting properties.
In an embodiment, a compound may include both a hole-transporting moiety and an electron-transporting moiety. A simple comparison between the total number of the hole-transporting moieties and the total number of the electron-transporting moieties in the compound may be a criterion for predicting whether the compound is a hole-transporting compound or an electron-transporting compound, but cannot be an absolute criterion. One of the reasons why such a simple comparison cannot be an absolute criterion is that one hole-transporting moiety and one electron-transporting moiety may not respectively have exactly the same ability to attract holes and electrons.
Therefore, a relatively reliable way to determine whether a compound having a certain structure is a hole-transporting compound or an electron-transporting compound may be to directly implement the compound in a device.
The bipolar host, which is a compound including both a hole-transporting moiety and an electron-transporting moiety, may be a compound capable of receiving both electrons and holes to a certain extent.
The host may include a compound represented by Formula 301:
[Ar301]xb11-[(L301)xb1-R301]xb21 [Formula 301]
In Formula 301,
Ar301 and L301 may each independently be a C3-C60 carbocyclic group unsubstituted or substituted with at least one R10a or a C1-C60 heterocyclic group unsubstituted or substituted with at least one R10a,
xb11 may be 1, 2, or 3,
xb1 may be an integer from 0 to 5,
R301 may be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C1-C60 alkyl group unsubstituted or substituted with at least one R10a, a C2-C60 alkenyl group unsubstituted or substituted with at least one R10a, a C2-C60 alkynyl group unsubstituted or substituted with at least one R10a, a C1-C60 alkoxy group unsubstituted or substituted with at least one R10a, a C3-C60 carbocyclic group unsubstituted or substituted with at least one R10a, a C1-C6 heterocyclic group unsubstituted or substituted with at least one R10a, —Si(Q301)(Q302)(Q303), —N(Q301)(Q302), —B(Q301)(Q302), —C(═O)(Q301), —S(═O)2(Q301), or —P(═O)(Q301)(Q302),
xb21 may be an integer from 1 to 5, and
Q301 to Q303 may each be the same as described in connection with Q1.
For example, in case that xb11 in Formula 301 is 2 or more, two or more of Ar301(s) may be linked to each other via a single bond.
In embodiments, the host may include a compound represented by Formula 301-1, a compound represented by Formula 301-2, or any combination thereof:
wherein in Formulae 301-1 and 301-2,
ring A301 to ring A304 may each independently be a C3-C60 carbocyclic group unsubstituted or substituted with at least one R10a or a C1-C60 heterocyclic group unsubstituted or substituted with at least one R10a,
X301 may be O, S, N-[(L304)xb4-R304], C(R304)(R305), or Si(R304)(R305),
xb22 and xb23 may each independently be 0, 1, or 2,
L301, xb1, and R301 may respectively be the same as those described herein,
L302 to L304 may each independently be the same as described in connection with L301,
xb2 to xb4 may each independently be the same as described in connection with xb1, and
R302 to R305 and R311 to R314 may each be the same as described in connection with R301.
In embodiments, the host may include an alkaline earth-metal complex. For example, the host may include a Be complex (for example, Compound H55), an Mg complex, a Zn complex, or any combination thereof.
In embodiments, the host may include one of Compounds H1 to H124, one of Compounds 1-1 to 1-22, one of Compounds 2-1 to 2-29, 9,10-di(2-naphthyl)anthracene (ADN), 2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN), 9,10-di-(2-naphthyl)-2-t-butyl-anthracene (TBADN), 4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP), 1,3-di-9-carbazolylbenzene (mCP), 1,3,5-tri(carbazol-9-yl)benzene (TCP), or any combination thereof:
[Phosphorescent Dopant]
The phosphorescent dopant may include at least one transition metal as a central metal.
The phosphorescent dopant may include a monodentate ligand, a bidentate ligand, a tridentate ligand, a tetradentate ligand, a pentadentate ligand, a hexadentate ligand, or any combination thereof.
The phosphorescent dopant may be electrically neutral.
For example, the phosphorescent dopant may include an organometallic compound represented by Formula 401:
M(L401)xc1(L402)xc2 [Formula 401]
wherein in Formulae 401 and 402,
M may be a transition metal (for example, iridium (Ir), platinum (Pt), palladium (Pd), osmium (Os), titanium (Ti), gold (Au), hafnium (Hf), europium (Eu), terbium (Tb), rhodium (Rh), rhenium (Re), or thulium (Tm)),
L401 may be a ligand represented by Formula 402, and xc1 may be 1, 2, or 3, wherein in case that xc1 is 2 or more, two or more of L401(s) may be identical to or different from each other,
L402 may be an organic ligand, and xc2 may be 0, 1, 2, 3, or 4, wherein in case that xc2 is 2 or more, two or more of L402 (s) may be identical to or different from each other,
X401 and X402 may each independently be nitrogen or carbon,
ring A401 and ring A402 may each independently be a C3-C60 carbocyclic group or a C1-C60 heterocyclic group,
T401 may be a single bond, —O—, —S—, —C(═O)—, —N(Q411)-, —C(Q411)(Q412)-, —C(Q411)═C(Q412)-, —C(Q411)=, or ═C(Q411)=,
X403 and X404 may each independently be a chemical bond (for example, a covalent bond or a coordination bond), O, S, N(Q413), B(Q413), P(Q413), C(Q413)(Q414), or Si(Q413)(Q414),
Q411 to Q414 may each be the same as described in connection with Q1,
R401 and R402 may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C1-C20 alkyl group unsubstituted or substituted with at least one R10a, a C1-C20 alkoxy group unsubstituted or substituted with at least one R10a, a C3-C60 carbocyclic group unsubstituted or substituted with at least one R10a, a C1-C60 heterocyclic group unsubstituted or substituted with at least one R10a, —Si(Q401)(Q402)(Q403), —N(Q401)(Q402), —B(Q401)(Q402), —C(═O)(Q401), —S(═O)2(Q401), or —P(═O)(Q401)(Q402),
Q401 to Q403 may each be the same as described in connection with Q1,
xc11 and xc12 may each independently be an integer from 0 to 10, and
* and *′ in Formula 402 each may indicate a binding site to M in Formula 401.
For example, in Formula 402, i) X401 may be nitrogen, and X402 may be carbon, or ii) each of X401 and X402 may be nitrogen.
In embodiments, in case that xc1 in Formula 401 is 2 or more, two ring A401(s) in two or more of L401(s) may optionally be linked to each other via T402, which is a linking group, or two ring A402 (s) may optionally be linked to each other via T403, which is a linking group (see Compounds PD1 to PD4 and PD7). T402 and T403 may each be the same as described in connection with T401.
L402 in Formula 401 may be an organic ligand. For example, L402 may include a halogen group, a diketone group (for example, an acetylacetonate group), a carboxylic acid group (for example, a picolinate group), —C(═O), an isonitrile group, a —CN group, a phosphorus group (for example, a phosphine group, a phosphite group, etc.), or any combination thereof.
The phosphorescent dopant may include, for example, one of Compounds PD1 to PD39, one of Compounds 3-11 to 3-18, or any combination thereof:
[Fluorescent Dopant]
The fluorescent dopant may include an amine group-containing compound, a styryl group-containing compound, or any combination thereof.
For example, the fluorescent dopant may include a compound represented by Formula 501:
wherein in Formula 501,
Ar501, L501 to L503, R501, and R502 may each independently be a C3-C60 carbocyclic group unsubstituted or substituted with at least one R10a or a C1-C60 heterocyclic group unsubstituted or substituted with at least one R10a,
xd1 to xd3 may each independently be 0, 1, 2, or 3, and
xd4 may be 1, 2, 3, 4, 5, or 6.
For example, Ar501 in Formula 501 may be a condensed cyclic group (for example, an anthracene group, a chrysene group, a pyrene group, etc.) in which three or more monocyclic groups are condensed together.
In embodiments, xd4 in Formula 501 may be 2.
For example, the fluorescent dopant may include one of Compounds FD2 to FD4 and FD6 to FD36, one of Compounds 5-1 to 5-6, DPVBi, DPAVBi, or any combination thereof:
[Thermally Activated Delayed Fluorescence Material]
The emission layer may include a thermally activated delayed fluorescence material.
In the specification, the thermally activated delayed fluorescence material may be selected from compounds capable of emitting delayed fluorescent light based on a delayed fluorescence emission mechanism.
The thermally activated delayed fluorescence material included in the emission layer may act as a host or a dopant depending on the type of other materials included in the emission layer.
In an embodiment, a difference between a triplet energy level (eV) of the thermally activated delayed fluorescence material and a singlet energy level (eV) of the thermally activated delayed fluorescence material may be equal to or greater than 0 eV and equal to or less than 0.5 eV. In case that the difference between the triplet energy level (eV) of the thermally activated delayed fluorescence material and the singlet energy level (eV) of the thermally activated delayed fluorescence material satisfies the above-described range, up-conversion from the triplet state to the singlet state of the thermally activated delayed fluorescence material may effectively occur, and thus, the luminescence efficiency of the light-emitting device 10 may be improved.
For example, the thermally activated delayed fluorescence material may include i) a material including at least one electron donor (for example, a π electron-rich C3-C60 cyclic group, such as a carbazole group) and at least one electron acceptor (for example, a sulfoxide group, a cyano group, or a π electron-deficient nitrogen-containing C1-C60 cyclic group), and ii) a material including a C8-C60 polycyclic group in which two or more cyclic groups are condensed while sharing boron (B).
Examples of the thermally activated delayed fluorescence material may include at least one of Compounds 4-1 to 4-16, Compounds DF1 to DF7, and DF10 to DF12:
[Electron Transport Region in Interlayer 130]
The electron transport region may have i) a single-layered structure consisting of a single layer consisting of a single material, ii) a single-layered structure consisting of a single layer consisting of multiple different materials, or iii) a multi-layered structure including multiple layers including different materials.
The electron transport region may include a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof.
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, or the like, the constituting layers of each structure being sequentially stacked each other from the emission layer.
The electron transport region (for example, the hole blocking layer or the electron transport layer in the electron transport region) may include a metal-free compound including at least one π electron-deficient nitrogen-containing C1-C60 cyclic group.
For example, the electron transport region may include a compound represented by Formula 601:
[Formula 601][Ar601]xe11-[(L601)xe1-R601]xe21
wherein in Formula 601,
Ar601 and L601 may each independently be a C3-C60 carbocyclic group unsubstituted or substituted with at least one R10a or a C1-C60 heterocyclic group unsubstituted or substituted with at least one R10a,
xe11 may be 1, 2, or 3,
xe1 may be 0, 1, 2, 3, 4, or 5,
R601 may be a C3-C60 carbocyclic group unsubstituted or substituted with at least one R10a, a C1-C60 heterocyclic group unsubstituted or substituted with at least one R10a, —Si(Q601)(Q602)(Q603), —C(═O)(Q601), —S(═O)2(Q601), or —P(═O)(Q601)(Q602),
Q601 to Q603 may each be the same as described in connection with Q1,
xe21 may be 1, 2, 3, 4, or 5, and
at least one of Ar601, L601, and R601 may each independently be a π electron-deficient nitrogen-containing C1-C60 cyclic group unsubstituted or substituted with at least one R10a.
For example, in case that xe11 in Formula 601 is 2 or more, two or more of Ar601(s) may be linked to each other via a single bond.
In embodiments, Ar601 in Formula 601 may be a substituted or unsubstituted anthracene group.
In embodiments, the electron transport region may include a compound represented by Formula 601-1:
wherein in Formula 601-1,
X614 may be N or C(R614), X615 may be N or C(R615), X616 may be N or C(R616), and at least one of X614 to X616 may be N,
L611 to L613 may each be the same as described in connection with L601,
xe611 to xe613 may each be the same as described in connection with xe1,
R611 to R613 may each be the same as described in connection with R601, and
R614 to R616 may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C1-C20 alkyl group, a C1-C20 alkoxy group, a C3-C60 carbocyclic group unsubstituted or substituted with at least one R10a, or a C1-C60 heterocyclic group unsubstituted or substituted with at least one R10a.
For example, xe1 and xe611 to xe613 in Formulae 601 and 601-1 may each independently be 0, 1, or 2.
The electron transport region may include one of Compounds ET1 to ET45, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), Alq3, BAlq, TAZ, NTAZ, or any combination thereof:
A thickness of the electron transport region may be in a range of about 100 Å to about 5,000 Å, for example, about 160 Å to about 4,000 Å. In case that the electron transport region includes a hole blocking layer, an electron transport layer, or any combination thereof, thicknesses of the hole blocking layer and the electron transport layer may each independently be in a range of about 20 Å to about 1,000 Å, for example, about 30 Å to about 300 Å, and a thickness of the electron transport layer may be in a range of about 100 Å to about 1,000 Å, for example, about 150 Å to about 500 Å. In case that the thicknesses of the hole blocking layer and/or the electron transport layer are within the ranges described above, satisfactory electron transporting characteristics may be obtained 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 an alkali metal complex, an alkaline earth metal complex, or any combination thereof. A metal ion of the alkali metal complex may be a Li ion, a Na ion, a K ion, a Rb ion, or a Cs ion, and a metal ion of the alkaline earth metal complex may be a Be ion, a Mg ion, a Ca ion, a Sr ion, or a Ba ion. A ligand coordinated with the metal ion of the alkali metal complex or the alkaline earth-metal complex may include hydroxyquinoline, hydroxyisoquinoline, hydroxybenzoquinoline, hydroxyacridine, hydroxyphenanthridine, hydroxyphenyloxazole, hydroxyphenylthiazole, hydroxyphenyloxadiazole, hydroxyphenylthiadiazole, hydroxyphenylpyridine, hydroxyphenylbenzimidazole, hydroxyphenylbenzothiazole, bipyridine, phenanthroline, cyclopentadiene, or any combination thereof.
For example, the metal-containing material may include a Li complex. The Li complex may include, for example, Compound ET-D1 (LiQ) or ET-D2:
The electron transport region may include an electron injection layer that facilitates the injection of electrons from the second electrode 150. The electron injection layer may be in contact (e.g., direct contact) with the second electrode 150.
The electron injection layer may have i) a single-layered structure consisting of a single layer consisting of a single material, ii) a single-layered structure consisting of a single layer consisting of multiple different materials, or iii) a multi-layered structure including multiple layers including different materials.
The electron injection layer may include an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal-containing compound, an alkaline earth metal-containing compound, a rare earth metal-containing compound, an alkali metal complex, an alkaline earth metal complex, a rare earth metal complex, or any combination thereof.
The alkali metal of the electron injection layer may include Li, Na, K, Rb, Cs, or any combination thereof. The alkaline earth metal may include Mg, Ca, Sr, Ba, or any combination thereof. The rare earth metal may include Sc, Y, Ce, Tb, Yb, Gd, or any combination thereof.
The alkali metal-containing compound, the alkaline earth metal-containing compound, and the rare earth metal-containing compound of the electron injection layer may be oxides, halides (for example, fluorides, chlorides, bromides, iodides, etc.), or tellurides of the alkali metal, the alkaline earth metal, and the rare earth metal, or any combination thereof.
The alkali metal-containing compound of the electron injection layer may include: alkali metal oxides, such as Li2O, Cs2O, or K2O; alkali metal halides, such as LiF, NaF, CsF, KF, LiI, NaI, CsI, or KI; or any combination thereof. The alkaline earth metal-containing compound of the electron injection layer may include an alkaline earth metal compound, such as BaO, SrO, CaO, BaxSr1-xO (wherein x is a real number satisfying the condition of 0<x<1), or BaxCa1-xO (wherein x is a real number satisfying the condition of 0<x<1). The rare earth metal-containing compound of the electron injection layer may include YbF3, ScF3, Sc2O3, Y2O3, Ce2O3, GdF3, TbF3, YbI3, ScI3, TbI3, or any combination thereof. In embodiments, the rare earth metal-containing compound of the electron injection layer may include lanthanide metal telluride.
Examples of the lanthanide metal telluride may include LaTe, CeTe, PrTe, NdTe, PmTe, SmTe, EuTe, GdTe, TbTe, DyTe, HoTe, ErTe, TmTe, YbTe, LuTe, La2Te3, Ce2Te3, Pr2Te3, Nd2Te3, Pm2Te3, Sm2Te3, Eu2Te3, Gd2Te3, Tb2Te3, Dy2Te3, Ho2Te3, Er2Te3, Tm2Te3, Yb2Te3, and Lu2Te3.
The alkali metal complex, the alkaline earth-metal complex, and the rare earth metal complex of the electron injection layer may include i) one of ions of the alkali metal, the alkaline earth metal, and the rare earth metal and ii), as a ligand bonded to the metal ion, for example, hydroxyquinoline, hydroxyisoquinoline, hydroxybenzoquinoline, hydroxyacridine, hydroxyphenanthridine, hydroxyphenyloxazole, hydroxyphenylthiazole, hydroxyphenyloxadiazole, hydroxyphenylthiadiazole, hydroxyphenylpyridine, hydroxyphenyl benzimidazole, hydroxyphenylbenzothiazole, bipyridine, phenanthroline, cyclopentadiene, or any combination thereof.
The electron injection layer may consist of an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal-containing compound, an alkaline earth metal-containing compound, a rare earth metal-containing compound, an alkali metal complex, an alkaline earth metal complex, a rare earth metal complex, or any combination thereof, as described above. In embodiments, the electron injection layer may further include an organic material (for example, a compound represented by Formula 601).
In an embodiment, the electron injection layer may consist of i) an alkali metal-containing compound (for example, alkali metal halide), or ii) a) an alkali metal-containing compound (for example, alkali metal halide); and b) an alkali metal, an alkaline earth metal, a rare earth metal, or any combination thereof. For example, the electron injection layer may be a KI:Yb co-deposited layer, an RbI:Yb co-deposited layer, a LiF:Yb co-deposited layer, or the like.
In case that the electron injection layer further includes an organic material, an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal-containing compound, an alkaline earth metal-containing compound, a rare earth metal-containing compound, an alkali metal complex, an alkaline earth-metal complex, a rare earth metal complex, or any combination thereof may be uniformly or non-uniformly dispersed in a matrix including the organic material.
A thickness of the electron injection layer may be in a range of about 1 Å to about 100 Å, for example, about 3 Å to about 90 Å. In case that the thickness of the electron injection layer is within the range described above, satisfactory electron injection characteristics may be obtained without a substantial increase in driving voltage.
[Second Electrode 150]
The second electrode 150 may be disposed on the interlayer 130 as described above. The second electrode 150 may be a cathode, which is an electron injection electrode, and as a material for forming the second electrode 150, a metal, an alloy, an electrically conductive compound, or any combination thereof, each having a low work function, may be used.
The second electrode 150 may include lithium (Li), silver (Ag), magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), ytterbium (Yb), silver-ytterbium (Ag—Yb), ITO, IZO, or any combination thereof. The second electrode 150 may be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode.
The second electrode 150 may have a single-layered structure or a multi-layered structure including multiple layers.
[Capping Layer]
A first capping layer may be located outside of the first electrode 110, and/or a second capping layer may be located outside of the second electrode 150. In detail, the light-emitting device 10 may have a structure in which the first capping layer, the first electrode 110, the interlayer 130, and the second electrode 150 are sequentially stacked each other in the stated order, a structure in which the first electrode 110, the interlayer 130, the second electrode 150, and the second capping layer are sequentially stacked each other in the stated order, or a structure in which the first capping layer, the first electrode 110, the interlayer 130, the second electrode 150, and the second capping layer are sequentially stacked each other in the stated order.
Light generated in the emission layer of the interlayer 130 of the light-emitting device 10 may be sent toward the outside through the first electrode 110, which is a semi-transmissive electrode or a transmissive electrode, and the first capping layer.
Light generated in the emission layer of the interlayer 130 of the light-emitting device 10 may be sent toward the outside through the second electrode 150, which is a semi-transmissive electrode or a transmissive electrode, and the second capping layer.
The first capping layer and the second capping layer may increase external luminescence efficiency according to the principle of constructive interference.
Accordingly, the light emission efficiency of the light-emitting device 10 may be increased, so that the luminescence efficiency of the light-emitting device 10 may be improved.
Each of the first capping layer and the second capping layer may include a material having a refractive index of about 1.6 or more (at 589 nm).
The first capping layer and the second capping layer may each independently be an organic capping layer including an organic material, an inorganic capping layer including an inorganic material, or an organic-inorganic composite capping layer including an organic material and an inorganic material.
At least one of the first capping layer and the second capping layer may each independently include a carbocyclic compound, a heterocyclic compound, an amine group-containing compound, a porphine derivative, a phthalocyanine derivative, a naphthalocyanine derivative, an alkali metal complex, an alkaline earth metal complex, or any combination thereof. The carbocyclic compound, the heterocyclic compound, and the amine group-containing compound may optionally be substituted with a substituent including O, N, S, Se, Si, F, Cl, Br, I, or any combination thereof. In an embodiment, at least one of the first capping layer and the second capping layer may each independently include an amine group-containing compound.
For example, at least one of the first capping layer and the second capping layer may each independently include a compound represented by Formula 201, a compound represented by Formula 202, or any combination thereof.
In embodiments, at least one of the first capping layer and the second capping layer may each independently include one of Compounds HT28 to HT33, one of Compounds CP1 to CP6, β-NPB, or any combination thereof:
[Electronic Apparatus]
The light-emitting device may be included in various electronic apparatuses. For example, the electronic apparatus including the light-emitting device may be a light-emitting apparatus, an authentication apparatus, or the like.
The electronic apparatus (for example, a light-emitting apparatus) may further include, in addition to the light-emitting device, i) a color filter, ii) a color conversion layer, or iii) a color filter and a color conversion layer. The color filter and/or the color conversion layer may be located in at least one traveling direction of light emitted from the light-emitting device. For example, the light emitted from the light-emitting device may be blue light. The light-emitting device is the same as described above. In an embodiment, the color conversion layer may include a quantum dot.
The electronic apparatus may include a first substrate. The first substrate may include multiple subpixels, the color filter may include multiple color filter areas respectively corresponding to the subpixels, and the color conversion layer may include multiple color conversion areas respectively corresponding to the subpixels.
A pixel defining film may be located between the subpixels to define each of the subpixels.
The color filter may further include multiple color filter areas and light-shielding patterns located between the color filter areas, and the color conversion layer may further include multiple color conversion areas and light-shielding patterns located between the color conversion areas.
The color filter areas (or the color conversion areas) may include a first area emitting first color light, a second area emitting second color light, and/or a third area emitting third color light, and the first color light, the second color light, and/or the third color light may have different maximum emission wavelengths. For example, the first color light may be red light, the second color light may be green light, and the third color light may be blue light. For example, the color filter areas (or the color conversion areas) may include quantum dots. In detail, the first area may include red quantum dots, the second area may include green quantum dots, and the third area may not include quantum dots. The quantum dot is the same as described herein. The first area, the second area, and/or the third area may each further include a scatterer.
For example, the light-emitting device may emit first light, the first area may absorb the first light to emit first-first color light, the second area may absorb the first light to emit second-first color light, and the third area may absorb the first light to emit third-first color light. In this regard, the first-first color light, the second-first color light, and the third-first color light may have different maximum emission wavelengths. In detail, the first light may be blue light, the first-first color light may be red light, the second-first color light may be green light, and the third-first color light may be blue light.
The electronic apparatus may further include a thin-film transistor, in addition to the light-emitting device as described above. The thin-film transistor may include a source electrode, a drain electrode, and an activation layer, wherein one of the source electrode and the drain electrode may be electrically connected to one of the first electrode and the second electrode of the light-emitting device.
The thin-film transistor may further include a gate electrode, a gate insulating film, and the like.
The activation layer may include crystalline silicon, amorphous silicon, an organic semiconductor, an oxide semiconductor, and the like.
The electronic apparatus may further include a sealing portion for sealing the light-emitting device. The sealing portion may be located between the color filter and/or the color conversion layer and the light-emitting device. The sealing portion may allow light from the light-emitting device to be sent to the outside, and simultaneously prevents ambient air and moisture from penetrating into the light-emitting device. The sealing portion may be a sealing substrate including a transparent glass substrate or a plastic substrate. The sealing portion may be a thin-film encapsulation layer including at least one layer of an organic layer and/or an inorganic layer. In case that the sealing portion is a thin-film encapsulating layer, the electronic apparatus may be flexible.
Various functional layers may be additionally disposed on the sealing portion, in addition to the color filter and/or the color conversion layer, according to the use of the electronic apparatus. Examples of the functional layers may include a touch screen layer, a polarizing layer, and the like. The touch screen layer may be a pressure-sensitive touch screen layer, a capacitive touch screen layer, or an infrared touch screen layer. The authentication apparatus may be, for example, a biometric authentication apparatus that authenticates an individual by using biometric information of a living body (for example, fingertips, pupils, etc.).
The authentication apparatus may further include, in addition to the light-emitting device as described above, a biometric information collector.
The electronic apparatus may be applied to various displays, light sources, lighting, personal computers (for example, a mobile personal computer), mobile phones, digital cameras, electronic organizers, electronic dictionaries, electronic game machines, medical instruments (for example, electronic thermometers, sphygmomanometers, blood glucose meters, pulse measurement devices, pulse wave measurement devices, electrocardiogram displays, ultrasonic diagnostic devices, or endoscope displays), fish finders, various measuring instruments, meters (for example, meters for a vehicle, an aircraft, and a vessel), projectors, and the like.
[Description of
The electronic apparatus of
The substrate 100 may be a flexible substrate, a glass substrate, or a metal substrate. A buffer layer 210 may be disposed on the substrate 100. The buffer layer 210 may prevent penetration of impurities through the substrate 100 and may provide a flat surface on the substrate 100.
The TFT may be disposed on the buffer layer 210. The TFT may include an activation layer 220, a gate electrode 240, a source electrode 260, and a drain electrode 270.
The activation layer 220 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 230 for insulating the activation layer 220 from the gate electrode 240 may be disposed on the activation layer 220, and the gate electrode 240 may be disposed on the gate insulating film 230.
An interlayer insulating film 250 may be disposed on the gate electrode 240.
The interlayer insulating film 250 may be located between the gate electrode 240 and the source electrode 260 and between the gate electrode 240 and the drain electrode 270 to provide insulation therebetween.
The source electrode 260 and the drain electrode 270 may be disposed on the interlayer insulating film 250. The interlayer insulating film 250 and the gate insulating film 230 may be formed to expose the source region and the drain region of the activation layer 220, and the source electrode 260 and the drain electrode 270 may be located in contact with the exposed portions of the source region and the drain region of the activation layer 220.
The TFT may be electrically connected to a light-emitting device to drive the light-emitting device, and may be covered and protected by a passivation layer 280.
The passivation layer 280 may include an inorganic insulating film, an organic insulating film, or any combination thereof. A light-emitting device may be provided on the passivation layer 280. The light-emitting device may include a first electrode 110, an interlayer 130, and a second electrode 150.
The first electrode 110 may be disposed on the passivation layer 280. The passivation layer 280 may be located to expose a certain region of the drain electrode 270 without fully covering the drain electrode 270, and the first electrode 110 may be located to be electrically connected to the exposed region of the drain electrode 270.
A pixel defining layer 290 including an insulating material may be disposed on the first electrode 110. The pixel defining layer 290 may expose a certain region of the first electrode 110, and the interlayer 130 may be formed in the exposed region of the first electrode 110. The pixel defining layer 290 may be a polyimide or polyacrylic organic film. Although not shown in
The second electrode 150 may be disposed on the interlayer 130, and a capping layer 170 may be additionally formed on the second electrode 150. The capping layer 170 may be formed to cover the second electrode 150.
The encapsulation portion 300 may be disposed on the capping layer 170.
The encapsulation portion 300 may be disposed on a light-emitting device to protect the light-emitting device from moisture or oxygen. The encapsulation portion 300 may include: an inorganic film including silicon nitride (SiNx), silicon oxide (SiOx), indium tin oxide, indium zinc oxide, or any combination thereof; an organic film including polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, polyethylene sulfonate, polyoxymethylene, polyarylate, hexamethyldisiloxane, an acrylic resin (for example, polymethyl methacrylate, polyacrylic acid, etc.), an epoxy-based resin (for example, aliphatic glycidyl ether (AGE), etc.), or any combination thereof; or a combination of the inorganic film and the organic film.
The electronic apparatus of
[Manufacturing Method]
Respective layers included in the hole transport region, the emission layer, and respective layers included in the electron transport region may be formed in a certain region by using various methods such as vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) deposition, ink-jet printing, laser-printing, laser-induced thermal imaging, and the like.
In case that the layers included in the hole transport region, the emission layer, and the layers included in the electron transport region are formed by vacuum deposition, the deposition may be performed at a deposition temperature of about 100° C. to about 500° C., a vacuum degree of about 10−8 torr to about 10−3 torr and at a deposition speed of about 0.01 Å/sec to about 100 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.
In case that the layers included in the hole transport region, the emission layer, and the layers included in the electron transport region are formed by spin coating, the spin coating may be performed at a coating speed of about 2,000 rpm to about 5,000 rpm and at a heat treatment temperature of about 80° C. to about 200° C., by taking into account a material to be included in a layer to be formed and the structure of a layer to be formed.
[General Definition of Substituents]
The term “C3-C60 carbocyclic group” as used herein may be a cyclic group consisting of carbon only as a ring-forming atom and having 3 to 60 carbon atoms, and the term “C1-C60 heterocyclic group” as used herein may be a cyclic group that has 1 to 60 carbon atoms and further has, in addition to carbon, a heteroatom as a ring-forming atom. The C3-C60 carbocyclic group and the C1-C60 heterocyclic group may each be a monocyclic group consisting of one ring or a polycyclic group in which two or more rings are condensed with each other. For example, the C1-C60 heterocyclic group may have 3 to 61 ring-forming atoms.
The term “cyclic group” as used herein may include both the C3-C60 carbocyclic group and the C1-C60 heterocyclic group.
The term “π electron-rich C3-C60 cyclic group” as used herein may be a cyclic group that has 3 to 60 carbon atoms and may not include *—N=*′ as a ring-forming moiety. The term “π electron-deficient nitrogen-containing C1-C60 cyclic group” as used herein may be a heterocyclic group that has 1 to 60 carbon atoms and includes *—N=*′ as a ring-forming moiety.
For example,
the C3-C60 carbocyclic group may be i) a T1 group or ii) a condensed cyclic group in which at least two T1 groups are condensed with each other (for example, a cyclopentadiene group, an adamantane group, a norbornane group, a benzene group, a pentalene group, a naphthalene group, an azulene group, an indacene group, an acenaphthylene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a perylene group, a pentaphene group, a heptalene group, a naphthacene group, a picene group, a hexacene group, a pentacene group, a rubicene group, a coronene group, an ovalene group, an indene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, an indenophenanthrene group, or an indenoanthracene group),
the C1-C60 heterocyclic group may be i) a T2 group, ii) a condensed cyclic group in which at least two T2 groups are condensed with each other, or iii) a condensed cyclic group in which at least one T2 group and at least one T1 group are condensed with each other (for example, a pyrrole group, a thiophene group, a furan group, an indole group, a benzoindole group, a naphthoindole group, an isoindole group, a benzoisoindole group, a naphthoisoindole group, a benzosilole group, a benzothiophene group, a benzofuran group, a carbazole group, a dibenzosilole group, a dibenzothiophene group, a dibenzofuran group, an indenocarbazole group, an indolocarbazole group, a benzofurocarbazole group, a benzothienocarbazole group, a benzosilolocarbazole group, a benzoindolocarbazole group, a benzocarbazole group, a benzonaphthofuran group, a benzonaphthothiophene group, a benzonaphthosilole group, a benzofurodibenzofuran group, a benzofurodibenzothiophene group, a benzothienodibenzothiophene group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzoisoxazole group, a benzothiazole group, a benzoisothiazole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a quinoxaline group, a benzoquinoxaline group, a quinazoline group, a benzoquinazoline group, a phenanthroline group, a cinnoline group, a phthalazine group, a naphthyridine group, an imidazopyridine group, an imidazopyrimidine group, an imidazotriazine group, an imidazopyrazine group, an imidazopyridazine group, an azacarbazole group, an azafluorene group, an azadibenzosilole group, an azadibenzothiophene group, an azadibenzofuran group, etc.),
the π electron-rich C3-C60 cyclic group may be i) a T1 group, ii) a condensed cyclic group in which at least two T1 groups are condensed with each other, iii) a T3 group, iv) a condensed cyclic group in which at least two T3 groups are condensed with each other, or v) a condensed cyclic group in which at least one T3 group and at least one T1 group are condensed with each other (for example, the C3-C60 carbocyclic group, a 1H-pyrrole group, a silole group, a borole group, a 2H-pyrrole group, a 3H-pyrrole group, a thiophene group, a furan group, an indole group, a benzoindole group, a naphthoindole group, an isoindole group, a benzoisoindole group, a naphthoisoindole group, a benzosilole group, a benzothiophene group, a benzofuran group, a carbazole group, a dibenzosilole group, a dibenzothiophene group, a dibenzofuran group, an indenocarbazole group, an indolocarbazole group, a benzofurocarbazole group, a benzothienocarbazole group, a benzosilolocarbazole group, a benzoindolocarbazole group, a benzocarbazole group, a benzonaphthofuran group, a benzonaphthothiophene group, a benzonaphthosilole group, a benzofurodibenzofuran group, a benzofurodibenzothiophene group, a benzothienodibenzothiophene group, etc.),
the π electron-deficient nitrogen-containing C1-C60 cyclic group may be i) a T4 group, ii) a condensed cyclic group in which at least two T4 groups are condensed with each other, iii) a condensed cyclic group in which at least one T4 group and at least one T1 group are condensed with each other, iv) a condensed cyclic group in which at least one T4 group and at least one T3 group are condensed with each other, or v) a condensed cyclic group in which at least one T4 group, at least one T1 group, and at least one T3 group are condensed with one another (for example, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzoisoxazole group, a benzothiazole group, a benzoisothiazole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a quinoxaline group, a benzoquinoxaline group, a quinazoline group, a benzoquinazoline group, a phenanthroline group, a cinnoline group, a phthalazine group, a naphthyridine group, an imidazopyridine group, an imidazopyrimidine group, an imidazotriazine group, an imidazopyrazine group, an imidazopyridazine group, an azacarbazole group, an azafluorene group, an azadibenzosilole group, an azadibenzothiophene group, an azadibenzofuran group, etc.),
the T1 group may be a cyclopropane group, a cyclobutane group, a cyclopentane group, a cyclohexane group, a cycloheptane group, a cyclooctane group, a cyclobutene group, a cyclopentene group, a cyclopentadiene group, a cyclohexene group, a cyclohexadiene group, a cycloheptene group, an adamantane group, a norbornane (or bicyclo[2.2.1]heptane) group, a norbornene group, a bicyclo[1.1.1]pentane group, a bicyclo[2.1.1]hexane group, a bicyclo[2.2.2]octane group, or a benzene group,
the T2 group may be a furan group, a thiophene group, a 1H-pyrrole group, a silole group, a borole group, a 2H-pyrrole group, a 3H-pyrrole group, an imidazole group, a pyrazole group, a triazole group, a tetrazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, an azasilole group, an azaborole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a tetrazine group, a pyrrolidine group, an imidazolidine group, a dihydropyrrole group, a piperidine group, a tetrahydropyridine group, a dihydropyridine group, a hexahydropyrimidine group, a tetrahydropyrimidine group, a dihydropyrimidine group, a piperazine group, a tetrahydropyrazine group, a dihydropyrazine group, a tetrahydropyridazine group, or a dihydropyridazine group,
the T3 group may be a furan group, a thiophene group, a 1H-pyrrole group, a silole group, or a borole group, and
the T4 group may be a 2H-pyrrole group, a 3H-pyrrole group, an imidazole group, a pyrazole group, a triazole group, a tetrazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, an azasilole group, an azaborole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, or a tetrazine group.
The terms “the cyclic group, the C3-C60 carbocyclic group, the C1-C60 heterocyclic group, the π electron-rich C3-C60 cyclic group, or the π electron-deficient nitrogen-containing C1-C60 cyclic group” as used herein may be a group condensed to any cyclic group, a monovalent group, or a polyvalent group (for example, a divalent group, a trivalent group, a tetravalent group, etc.) according to the structure of a formula for which the corresponding term is used. For example, the “benzene group” may be a benzo group, a phenyl group, a phenylene group, or the like, which may be readily understood by one of ordinary skill in the art according to the structure of a formula including the “benzene group.”
Examples of the monovalent C3-C60 carbocyclic group and the monovalent C1-C60 heterocyclic group may include a C3-C10 cycloalkyl group, a C1-C60 heterocycloalkyl group, a C3-C10 cycloalkenyl group, a C1-C60 heterocycloalkenyl group, a C6-C60 aryl group, a C1-C60 heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group. Examples of the divalent C3-C60 carbocyclic group and the divalent C1-C60 heterocyclic group may include a C3-C10 cycloalkylene group, a C1-C60 heterocycloalkylene group, a C3-C10 cycloalkenylene group, a C1-C60 heterocycloalkenylene group, a C6-C60 arylene group, a C1-C60 heteroarylene group, a divalent non-aromatic condensed polycyclic group, and a divalent non-aromatic condensed heteropolycyclic group.
The term “C1-C60 alkyl group” as used herein may be a linear or branched aliphatic hydrocarbon monovalent group that has 1 to 60 carbon atoms, and examples thereof may include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a tert-pentyl group, a neopentyl group, an isopentyl group, a sec-pentyl group, a 3-pentyl group, a sec-isopentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isooctyl group, a sec-octyl group, a tert-octyl group, an n-nonyl group, an isononyl group, a sec-nonyl group, a tert-nonyl group, an n-decyl group, an isodecyl group, a sec-decyl group, and a tert-decyl group. The term “C1-C60 alkylene group” as used herein may be a divalent group having the same structure as the C1-C60 alkyl group.
The term “C2-C60 alkenyl group” as used herein may be a monovalent hydrocarbon group having at least one carbon-carbon double bond in the middle or at the terminus of the C2-C60 alkyl group, and examples thereof may include an ethenyl group, a propenyl group, and a butenyl group. The term “C2-C60 alkenylene group” as used herein may be a divalent group having the same structure as the C2-C60 alkenyl group.
The term “C2-C60 alkynyl group” as used herein may be a monovalent hydrocarbon group having at least one carbon-carbon triple bond in the middle or at the terminus of the C2-C60 alkyl group, and examples thereof may include an ethynyl group and a propynyl group. The term “C2-C60 alkynylene group” as used herein may be a divalent group having the same structure as the C2-C60 alkynyl group.
The term “C1-C60 alkoxy group” as used herein may be a monovalent group represented by —OA101 (wherein A101 is the C1-C60 alkyl group), and examples thereof may include a methoxy group, an ethoxy group, and an isopropyloxy group.
The term “C3-C10 cycloalkyl group” as used herein may be a monovalent saturated hydrocarbon cyclic group having 3 to 10 carbon atoms, and examples thereof may include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group (or bicyclo[2.2.1]heptyl group), a bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl group, and a bicyclo[2.2.2]octyl group. The term “C3-C10 cycloalkylene group” as used herein may be a divalent group having the same structure as the C3-C10 cycloalkyl group.
The term “C1-C60 heterocycloalkyl group” as used herein may be a monovalent cyclic group of 1 to 10 carbon atoms, further including, in addition to carbon atoms, at least one heteroatom, as ring-forming atoms, and examples thereof include a 1,2,3,4-oxatriazolidinyl group, a tetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term “C1-C60 heterocycloalkylene group” as used herein may be a divalent group having the same structure as the C1-C60 heterocycloalkyl group.
The term “C3-C10 cycloalkenyl group” as used herein may be a monovalent cyclic group that has 3 to 10 carbon atoms and at least one carbon-carbon double bond in the ring thereof and no aromaticity, and examples thereof may include a cyclopentenyl group, a cyclohexenyl group, and a cycloheptenyl group. The term “C3-C10 cycloalkenylene group” as used herein may be a divalent group having the same structure as the C3-C10 cycloalkenyl group.
The term “C1-C10 heterocycloalkenyl group” as used herein may be a monovalent cyclic group of 1 to 10 carbon atoms, further including, in addition to carbon atoms, at least one heteroatom, as ring-forming atoms, and having at least one carbon-carbon double bond in the cyclic structure thereof. Examples of the C1-C10 heterocycloalkenyl group may include a 4,5-dihydro-1,2,3,4-oxatriazolyl group, a 2,3-dihydrofuranyl group, and a 2,3-dihydrothiophenyl group. The term “C1-C10 heterocycloalkenylene group” as used herein may be a divalent group having the same structure as the C1-C10 heterocycloalkenyl group.
The term “C6-C60 aryl group” as used herein may be a monovalent group having a carbocyclic aromatic system of 6 to 60 carbon atoms, and the term “C6-C60 arylene group” as used herein may be a divalent group having a carbocyclic aromatic system of 6 to 60 carbon atoms. Examples of the C6-C60 aryl group include a phenyl group, a pentalenyl group, a naphthyl group, an azulenyl group, an indacenyl group, an acenaphthyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a heptalenyl group, a naphthacenyl group, a picenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, and an ovalenyl group. In case that the C6-C60 aryl group and the C6-C60 arylene group each include two or more rings, the two or more rings may be condensed with each other.
The term “C1-C60 heteroaryl group” as used herein may be a monovalent group having a heterocyclic aromatic system of 1 to 60 carbon atoms, further including, in addition to carbon atoms, at least one heteroatom, as ring-forming atoms. The term “C1-C60 heteroarylene group” as used herein may be a divalent group having a heterocyclic aromatic system of 1 to 60 carbon atoms, further including, in addition to carbon atoms, at least one heteroatom, as ring-forming atoms. Examples of the C1-C60 heteroaryl group may include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, a benzoquinolinyl group, an isoquinolinyl group, a benzoisoquinolinyl group, a quinoxalinyl group, a benzoquinoxalinyl group, a quinazolinyl group, a benzoquinazolinyl group, a cinnolinyl group, a phenanthrolinyl group, a phthalazinyl group, and a naphthyridinyl group. In case that the C1-C60 heteroaryl group and the C1-C60 heteroarylene group each include two or more rings, the two or more rings may be condensed with each other.
The term “monovalent non-aromatic condensed polycyclic group” as used herein may be a monovalent group (for example, having 8 to 60 carbon atoms) having two or more rings condensed to each other, only carbon atoms as ring-forming atoms, and no aromaticity in its entire molecular structure. Examples of the monovalent non-aromatic condensed polycyclic group may include an indenyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, an indenophenanthrenyl group, and an indenoanthracenyl group. The term “divalent non-aromatic condensed polycyclic group” as used herein may be 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 may be a monovalent group (for example, having 1 to 60 carbon atoms) having two or more rings condensed to each other, further including, in addition to carbon atoms, at least one heteroatom, as ring-forming atoms, and having non-aromaticity in its entire molecular structure. Examples of the monovalent non-aromatic condensed heteropolycyclic group may include a pyrrolyl group, a thiophenyl group, a furanyl group, an indolyl group, a benzoindolyl group, a naphthoindolyl group, an isoindolyl group, a benzoisoindolyl group, a naphthoisoindolyl group, a benzosilolyl group, a benzothiophenyl group, a benzofuranyl group, a carbazolyl group, a dibenzosilolyl group, a dibenzothiophenyl group, a dibenzofuranyl group, an azacarbazolyl group, an azafluorenyl group, an azadibenzosilolyl group, an azadibenzothiophenyl group, an azadibenzofuranyl group, a pyrazolyl group, an imidazolyl group, a triazolyl group, a tetrazolyl group, an oxazolyl group, an isoxazolyl group, a thiazolyl group, an isothiazolyl group, an oxadiazolyl group, a thiadiazolyl group, a benzopyrazolyl group, a benzimidazolyl group, a benzoxazolyl group, a benzothiazolyl group, a benzoxadiazolyl group, a benzothiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an imidazotriazinyl group, an imidazopyrazinyl group, an imidazopyridazinyl group, an indeno carbazolyl group, an indolocarbazolyl group, a benzofurocarbazolyl group, a benzothienocarbazolyl group, a benzosilolocarbazolyl group, a benzoindolocarbazolyl group, a benzocarbazolyl group, a benzonaphthofuranyl group, a benzonaphthothiophenyl group, a benzonaphtho silolyl group, a benzofurodibenzofuranyl group, a benzofurodibenzothiophenyl group, and a benzothienodibenzothiophenyl group. The term “divalent non-aromatic condensed heteropolycyclic group” as used herein may be a divalent group having the same structure as the monovalent non-aromatic condensed heteropolycyclic group.
The term “C6-C60 aryloxy group” as used herein may be —OA102 (wherein A102 is the C6-C60 aryl group), and the term “C6-C60 arylthio group” as used herein may be —SA103 (wherein A103 is the C6-C60 aryl group).
The term “C7-C60 arylalkyl group” as used herein may be -A104A105 (wherein A104 is a C1-C54 alkylene group, and A105 is a C6-C59 aryl group), and the term “C2-C60 heteroarylalkyl group” as used herein may be -A106A107 (wherein A106 is a C1-C59 alkylene group, and A107 is a C1-C59 heteroaryl group).
The term “R10a” as used herein may be:
deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or a nitro group;
a C1-C60 alkyl group, a C2-C60 alkenyl group, a C2-C60 alkynyl group, or a C1-C60 alkoxy group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C3-C60 carbocyclic group, a C1-C60 heterocyclic group, a C6-C60 aryloxy group, a C6-C60 arylthio group, a C7-C60 arylalkyl group, a C2-C60 heteroarylalkyl group, —Si(Q11)(Q12)(Q13), —N(Q11)(Q12), —B(Q11)(Q12), —C(═O)(Q11), —S(═O)2(Q11), —P(═O)(Q11)(Q12), or any combination thereof;
a C3-C60 carbocyclic group, a C1-C60 heterocyclic group, a C6-C60 aryloxy group, a C6-C60 arylthio group, a C7-C60 arylalkyl group, or a C2-C60 heteroarylalkyl group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C1-C60 alkyl group, a C2-C60 alkenyl group, a C2-C60 alkynyl group, a C1-C60 alkoxy group, a C3-C60 carbocyclic group, a C1-C60 heterocyclic group, a C6-C60 aryloxy group, a C6-C60 arylthio group, a C7-C60 arylalkyl group, a C2-C60 heteroarylalkyl group, —Si(Q21)(Q22)(Q23), —N(Q21)(Q22), —B(Q21)(Q22), —C(═O)(Q21), —S(═O)2(Q21), —P(═O)(Q21)(Q22), or any combination thereof; or
—Si(Q31)(Q32)(Q33), —N(Q31)(Q32), —B(Q31)(Q32), —C(═O)(Q31), —S(═O)2(Q31), or —P(═O)(Q31)(Q32).
Q1 to Q3, Q11 to Q13, Q21 to Q23, and Q31 to Q33 used herein may each independently be: hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; a C1-C60 alkyl group; a C2-C60 alkenyl group; a C2-C60 alkynyl group; a C1-C60 alkoxy group; or a C3-C60 carbocyclic group, a C1-C60 heterocyclic group, a C7-C60 arylalkyl group, or a C2-C60 heteroaryl alkyl group, each substituted with deuterium, —F, a cyano group, a C1-C60 alkyl group, a C1-C60 alkoxy group, a phenyl group, a biphenyl group, or any combination thereof.
The term “heteroatom” as used herein may be any atom other than a carbon atom. Examples of the heteroatom may include O, S, N, P, Si, B, Ge, Se, or any combination thereof.
The term “the third-row transition metal” as used herein may include hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), and the like.
“Ph” as used herein may be a phenyl group, “Me” as used herein may be a methyl group, “Et” as used herein may be an ethyl group, “ter-Bu” or “But” as used herein may be a tert-butyl group, and “OMe” as used herein may be a methoxy group.
The term “biphenyl group” as used herein may be “a phenyl group substituted with a phenyl group.” In other words, the “biphenyl group” may be a substituted phenyl group having a C6-C60 aryl group as a substituent.
The term “terphenyl group” as used herein may be “a phenyl group substituted with a biphenyl group.” In other words, the “terphenyl group” may be a substituted phenyl group having, as a substituent, a C6-C60 aryl group substituted with a C6-C60 aryl group.
The maximum number of carbon atoms in this substituent definition section is an example only. For example, the maximum carbon number of 60 in the C1-C60 alkyl group is an example, and the definition of the alkyl group equally applies to a C1-C20 alkyl group. The same also applies to other cases.
* and *′ as used herein, unless defined otherwise, each may be a binding site to a neighboring atom in a corresponding formula.
Hereinafter, a compound and light-emitting device according to embodiments will be described in detail with reference to Examples.
Manufacture of light-emitting device
A glass substrate (anode, ITO 300 Å/Ag 50 Å/ITO 300 Å) was cut to a size of 50 mm×50 mm×0.7 mm, cleaned by sonication with isopropyl alcohol and pure water each for 5 minutes, cleaned by irradiation of ultraviolet rays and exposure of ozone thereto for 30 minutes, and then loaded into a vacuum deposition apparatus.
HAT-CN was vacuum-deposited on the glass substrate to form a hole injection layer having a thickness of 150 Å.
Subsequently, Compound 1-2 was vacuum-deposited thereon to a thickness of 1,000 Å to form a hole transport layer as a single layer.
Compound 1-21 as a first host, Compound 2-5 as a second host, Compound 3-11 as a phosphorescent dopant, and Compound 5-1 as a fluorescent dopant were deposited on the hole transport layer to form an emission layer having a thickness of 150 Å (weight ratio of first host:second host:phosphorescent dopant:fluorescent dopant=7:3:1:0.1).
ET-1 was deposited on the emission layer to a thickness of 50 Å to form a first electron transport layer. Subsequently, ET-2 and Liq were deposited thereon at a weight ratio of 5:5 to a thickness of 200 Å to form a second electron transport layer.
Liq was vacuum-deposited on the second electron transport layer to a thickness of 10 Å, and subsequently, AgMg was vacuum-deposited thereon to a thickness of 100 Å (wherein a doping ratio of Mg was 5 wt %) to form a cathode, thereby completing the manufacture of a light-emitting device.
A light-emitting device was manufactured in the same manner as in Comparative Example 1, except that Compound 1-2 was deposited on the hole injection layer to a thickness of 500 Å to form a first hole transport layer, and subsequently, Compound 1-11 was deposited thereon to a thickness of 500 Å to form a second hole transport layer.
The HOMO energy level of Compound 1-2, which is −5.12 eV, is different from the HOMO energy level of Compound 1-11, which is −5.20 eV.
A light-emitting device was manufactured in the same manner as in Comparative Example 1, except that Compound 1-2 was deposited on the hole injection layer to a thickness of 300 Å to form a first hole transport layer, and subsequently, Compound 1-11 was deposited thereon to a thickness of 400 Å to form a second hole transport layer, followed by depositing Compound 1-2 thereon to a thickness of 300 Å to form a third hole transport layer.
A light-emitting device was manufactured in the same manner as in Comparative Example 1, except that Compound 1-11 was deposited on the hole injection layer to a thickness of 1,000 Å to form a hole transport layer as a single layer.
A light-emitting device was manufactured in the same manner as in Comparative Example 1, except that Compound 100 was deposited on the hole injection layer to a thickness of 500 Å to form a first hole transport layer, and subsequently, Compound 1-11 was deposited thereon to a thickness of 500 Å to form a second hole transport layer.
To evaluate the characteristics of each of the light-emitting devices manufactured according to Comparative Examples 1 to 3 and Examples 1 and 2, the driving voltage and lifespan at a current density of 10 mA/cm2 were measured, and the results thereof are shown in Table 1.
The driving voltage and lifespan of a light-emitting device were measured by using a measurement device C9920-2-12 of Hamamatsu Photonics Inc.
Referring to Table 1, it was confirmed that the light-emitting devices of Examples 1 and 2 had excellent driving voltage and lifespan compared to the light-emitting devices of Comparative Examples 1 to 3.
According to the embodiments, a light-emitting device may exhibit low driving voltage and improved lifespan, as compared with devices in the related art.
It should be understood that embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments. While embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2022-0005329 | Jan 2022 | KR | national |
