Patent Application
20240008361
This application claims priority to and benefits of Korean Patent Application No. 10-2022-0079994 under 35 U.S.C. § 119, filed on Jun. 29, 2022, in the Korean Intellectual Property Office, 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 is located on a substrate, and a hole transport region, an emission layer, an electron transport region, and a second electrode are sequentially formed on the first electrode. Holes provided from the first electrode move toward the emission layer through the hole transport region, and electrons provided from the second electrode move toward the emission layer through the electron transport region. Carriers, such as holes and electrons, recombine in the emission layer to produce light.
It is to be understood that this background of the technology section is, in part, intended to provide useful background for understanding the technology. However, this background of the technology section may also include ideas, concepts, or recognitions that were not part of what was known or appreciated by those skilled in the pertinent art prior to a corresponding effective filing date of the subject matter disclosed herein.
Embodiments may include a light-emitting device having improved 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 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
According to an embodiment, the first electrode may be an anode, the second layer may be a cathode, the interlayer may further include a hole transport region between the first electrode and the emission layer, and
According to an embodiment, the interlayer may further include a hole injection layer, and the hole injection layer may include a p-dopant.
According to an embodiment, the first electrode may be an anode, the second electrode may be a cathode, and the interlayer may further include an electron transport region between the second electrode and the emission layer, and
According to an embodiment, the electron transport layer may include a metal-containing material.
According to an embodiment, the metal-containing material may include an alkali metal complex, an alkaline earth-metal complex, or any combination thereof.
According to an embodiment, the dopant may be a phosphorescent dopant.
According to an embodiment, an amount of the dopant in the emission layer may be in a range of about 1% to about 50%, as a volume ratio.
According to an embodiment, the electron transport host compound may include a silicon (Si) moiety, a triazine moiety, a pyrimidine moiety, a pyridine moiety, a phenanthroline moiety, a triazole moiety, or any combination thereof.
According to an embodiment, the electron transport host compound may be represented by Formula 1, which is explained below.
According to an embodiment, the p-dopant may include one of Compounds P1 to P6, which are explained below.
According to an embodiment, the emission layer may further include a hole transport host compound.
According to an embodiment, the hole transport host compound may include an aryl amine moiety, a carbazole moiety, a fluorene moiety, or any combination thereof.
According to an embodiment, a weight ratio of the electron transport host compound to the hole transport host compound may be in a range of about 99:1 to about 1:99.
According to an embodiment, the light-emitting device may further include a hole injection layer, an electron blocking layer, a hole blocking layer, and an electron injection layer, wherein
According to an embodiment, the light-emitting device may further include at least one of a first capping layer outside the first electrode and a second capping layer outside the second electrode.
According to an embodiment, a refractive index of the first capping layer and/or the second capping layer may each independently be greater than or equal to about 1.6.
According to embodiments, an electronic apparatus may include the light-emitting device.
According to an embodiment, the electronic apparatus may further include a thin-film transistor, wherein
According to an embodiment, the electronic device may be a flat panel display, a curved display, a computer monitor, a medical monitor, a television, an advertisement board, an indoor light, an outdoor light, a signaling light, a head-up display, a fully transparent display, a partially transparent display, a flexible display, a rollable display, a foldable display, a stretchable display, a laser printer, a telephone, a mobile phone, a tablet, a phablet, a personal digital assistant (PDA), a wearable device, a laptop computer, a digital camera, a camcorder, a viewfinder, a microdisplay, a 3D display, a virtual reality display, a augmented-reality display, a vehicle, a video wall comprising multiple displays tiled together, a theater screen, a stadium screen, a phototherapy device, or a sign.
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 and features of the disclosure will be more apparent by describing in detail embodiments thereof with reference to 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.
As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 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.
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.
In a light-emitting device, an emission layer may include a light-emitting dopant and a host that is responsible for charge transfer and energy transfer, and common layers for hole and electron injection/transport may be between each of both electrodes and the emission layer.
The light-emitting device may have an energetic stepped stacked structure for smooth electron and hole injection. However, design techniques for a device may be further required for improvement of lifespan and driving voltage for high-quality products.
According to embodiments, a light-emitting device may include:
The device lifespan may be determined by a charge amount and exciton amount of the device, and the device driving voltage may be determined by the charge amount of the device. The light-emitting device according to an embodiment may simultaneously improve low driving voltage and lifespan through controlling charge mobility characteristics of a material used for the device.
In the light-emitting device according to an embodiment, the hole mobility of the hole transport layer may be greater than 1×10−4 cm2/Vs, the electron mobility of the electron transport layer may be greater than 1×10−5 cm2/Vs, and the electron mobility of the electron transport host compound may be less than 1×10−8 cm2/Vs.
When the hole mobility of the hole transport layer, the electron mobility of the electron transport layer, and the electron mobility of the electron transport host compound of the light-emitting device according to an embodiment simultaneously satisfy the above ranges, the light-emitting device may show improved lifespan while driving at a relatively low voltage.
The hole mobility of the hole transport layer exceeds 1×10−4 cm2/Vs, which may relate to a hole mobility value of a material included in the hole transport layer.
For example, when the hole transport layer includes one type of hole transport layer material, and when the hole mobility of the hole transport layer material is greater than 1×10−4 cm2/Vs, the hole mobility of the hole transport layer may be greater than 1×10−4 cm2/Vs.
For example, when the hole transport layer includes two or more types of hole transport layer materials (for example, hole transport layer material A, hole transport layer material B), even when the hole mobility of the hole transport layer material A is less than 1×10−4 cm2/Vs, if the hole mobility of the hole transport layer material B is greater than 1×10−4 cm2/Vs and a mixing ratio of the hole transport layer materials A and B is appropriate, the hole mobility of the hole transport layer may be greater than 1×10−4 cm2/Vs.
For example, the hole transport layer according to an embodiment may include one type of hole transport layer material. The hole mobility of the one type of hole transport layer material may be greater than 1×10−4 cm2/Vs, and the hole mobility of the hole transport layer may be greater than 1×10−4 cm2/Vs.
Considering that the hole mobility of the hole transport layer needs to be greater than 1×10−4 cm2/Vs, the structure of the hole transport layer material is not limited thereto. More details of the hole transport layer materials will be described later.
In the light-emitting device according to an embodiment, the first electrode may be an anode, the second electrode may be a cathode, and 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 interlayer may further include a hole injection layer, and the hole injection layer may include a p-dopant. More details of the p-dopant will be described later.
In the light-emitting device according to an embodiment, the first electrode may be an anode, the second electrode may be a cathode, and the interlayer may further include an electron transport region between the second electrode and the emission layer, and the electron transport region may include an electron injection layer, a hole blocking layer, or any combination thereof.
The electron mobility of the electron transport layer exceeds 1×10−4 cm2/Vs, which may relate to an electron mobility value of a material included in the electron transport layer.
In an embodiment, when the electron transport layer includes one type of electron transport layer material, and when the electron mobility of the electron transport layer material is greater than 1×10−4 cm2/Vs, the electron mobility of the electron transport layer may be greater than 1×10−4 cm2/Vs.
In an embodiment, when the electron transport layer includes two or more types of electron transport layer materials (for example, electron transport layer material C, electron transport layer material D), even when the electron mobility of the electron transport layer material C is less than 1×10−4 cm2/Vs, if the electron mobility of the electron transport layer material D is greater than 1×10−4 cm2/Vs and a mixing ratio of the electron transport layer materials C and D is appropriate, the electron mobility of the electron transport layer may be greater than 1×10−4 cm2/Vs.
Considering that the electron mobility of the electron transport layer needs to be greater than 1×10−4 cm2/Vs, the structure of the electron transport layer material is not limited thereto. More details of the electron transport layer materials will be described later.
In an embodiment, the electron transport layer may include a metal-containing material.
The metal-containing material may include an alkali metal complex, an alkaline earth-metal complex, or any combination thereof. Details of the alkali metal complex, alkaline earth-metal complex, and the like will be described later.
In an embodiment, the electron transport layer according to an embodiment may include an electron transport layer material and may also include a metal-containing material. The hole mobility of the electron transport layer may be greater than 1×10−4 cm2/Vs.
In an embodiment, the dopant may be a phosphorescent dopant. In an embodiment, the dopant may be a platinum-based (Pt-based) complex.
In an embodiment, an amount of the dopant in the emission layer may be in a range of about 1% to about 50%, as a volume ratio. In an embodiment, the amount of the dopant in the emission layer may be about 0.01 parts by weight to about 15 parts by weight based on 100 parts by weight of the host. More details of the dopant will be described later.
Considering that the electron mobility of the electron transport host compound needs to be less than 1×10−8 cm2/Vs, the structure of the electron transport host compound is not limited thereto.
In an embodiment, the electron transport host compound of the emission layer may include a Si moiety, a triazine moiety, a pyrimidine moiety, a pyridine moiety, a phenanthroline moiety, a triazole moiety, or any combination thereof.
For example, the electron transport host compound may be represented by Formula 1:
In Formulae 1 and 1-1,
In an embodiment, the compound represented by Formula 1 may include at least one deuterium. In an embodiment, all hydrogen included in the compound represented by Formula 1 may be substituted with deuterium.
In an embodiment, examples of the compound represented by Formula 1 having an electron mobility of less than 1×10−8 cm2/Vs may include Compound ETH2, Compound ETH2_D, Compound ETH4, or any combination thereof:
Compound ETH2_D may be a compound in which all hydrogen of Compound ETH2 may be substituted with deuterium.
In an embodiment, the emission layer may further include a hole transport host compound. For example, the hole transport host compound may include an aryl amine moiety, a carbazole moiety, a fluorene moiety, or any combination thereof.
For example, the hole transport host compound may be represented by Formula 2:
In Formula 2, R1 to R3 may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono 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-C10 cycloalkyl group unsubstituted or substituted with at least one R10a, a C1-C10 heterocycloalkyl group unsubstituted or substituted with at least one R10a, a C3-C10 cycloalkenyl group unsubstituted or substituted with at least one R10a, a C1-C10 heterocycloalkenyl group unsubstituted or substituted with at least one R10a, a C6-C60 aryl group unsubstituted or substituted with at least one R10a, a C6-C60 aryloxy group unsubstituted or substituted with at least one R10a, a C6-C60 arylthio group unsubstituted or substituted with at least one R10a, a C1-C60 heteroaryl group unsubstituted or substituted with at least one R10a, a C1-C60 heteroaryloxy group unsubstituted or substituted with at least one R10a, a C1-C60 heteroarylthio group unsubstituted or substituted with at least one R10a, a monovalent non-aromatic condensed polycyclic group unsubstituted or substituted with at least one R10a, a monovalent non-aromatic condensed heteropolycyclic group unsubstituted or substituted with at least one R10a, —Si(Q1)(Q2)(Q3), —B(Q1)(Q2), —N(Q1)(Q2), —P(Q1)(Q2), —C(═O)(Q1), —S(═O)(Q1), —S(═O)2(Q1), —P(═O)(Q1)(Q2), or —P(═S)(Q1)(Q2),
In an embodiment, a weight ratio of the electron transport host compound to the hole transport host compound may be in a range of about 99:1 to about 1:99. In an embodiment, a weight ratio of the electron transport host compound and the hole transport host compound may be in a range of about 70:30 to about 30:70. In an embodiment, a weight ratio of the electron transport host compound and the hole transport host compound may be in a range of about 65:35 to about 35:65. In an embodiment, a weight ratio of the electron transport host compound and the hole transport host compound may be in a range of about 55:45 to about 45:55. When the weight ratios of the electron transport host compound and the hole transport host compound are within the ranges above, the hole transport may be in a desirable balance with the electron transport.
When the emission layer of the light-emitting device according to an embodiment includes a hole transport host compound and an electron transport host compound, the hole mobility of the hole transport layer is greater than 1×10−4 cm2/Vs, the electron mobility of the electron transport layer is greater than 1×10−5 cm2/Vs, and the electron mobility of the electron transport host compound is less than 1×10−8 cm2/Vs, the electron mobility of the emission layer (not including the dopant) including the hole transport host compound and the electron transport host compound may be less than 1×10−8 cm2/Vs. When the electron mobility of the emission layer (not including the dopant) is less than 1×10−8 cm2/Vs, the light-emitting device may show improved lifespan while driving at a relatively low voltage.
In an embodiment, the light-emitting device may further include a hole injection layer, an electron blocking layer, a hole blocking layer, and an electron injection layer,
For example, the thickness of the hole injection layer may be in a range of about 50 Å to about 200 Å, the thickness of the hole transport layer may be in a range of about 500 Å to about 1,500 Å, the thickness of the electron blocking layer may be in a range of about 50 Å to about 150 Å, the thickness of the emission layer may be in a range of about 150 Å to about 500 Å, the thickness of the hole blocking layer may be in a range of about 50 Å to about 150 Å, the thickness of the electron transport layer may be in a range of about 200 Å to about 400 Å, and the thickness of the electron injection layer may be in range of about 5 Å to about 30 Å.
When the thicknesses of the hole injection layer, the hole transport layer, the electron blocking layer, the emission layer, the hole blocking layer, the electron transport layer, and the electron injection layer are within the above ranges, the light-emitting device may have excellent driving voltage and lifespan.
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,
The term “interlayer” as used herein refers to a single layer and/or all 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. When the first electrode 110 is an anode, a 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. When the first electrode 110 is a transmissive electrode, a 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, when the first electrode 110 is a semi-transmissive electrode or a reflective electrode, a 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 located on the first electrode 110. The interlayer 130 may include an emission layer.
The interlayer 130 may further include a hole transport region between the first electrode 110 and the emission layer, and an electron transport region 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 quantum dots, or the like.
In embodiments, the interlayer 130 may include two or more emission layers stacked between the first electrode 110 and the second electrode 150 and at least one charge generation layer located between the two or more emission layers. When the interlayer 130 includes the two or more emission layers and the at least one 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 a structure consisting of a layer consisting of a single material, a structure consisting of a layer including different materials, or a 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.
In an embodiment, the hole transport region may have a multilayer structure including a hole injection layer/hole transport layer structure, a hole injection layer/hole transport layer/emission auxiliary layer structure, a hole transport layer/emission auxiliary layer structure, or a hole injection layer/hole transport layer/electron blocking layer structure, wherein the layers of each structure may be stacked from the first electrode 110 in its respective stated order, but the structure of the hole transport region is not limited thereto.
The hole transport region may include a compound represented by Formula 201, a compound represented by Formula 202, or any combination thereof. In an embodiment, the hole transport layer material included in the hole transport layer may include a compound represented by Formula 201, a compound represented by Formula 202, or any combination thereof:
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,
In an embodiment, the compound represented by Formulae 201 and 202 may include at least one deuterium. In an embodiment, all hydrogen included in the compound represented by Formulae 201 and 202 may be substituted with deuterium.
In an embodiment, each of Formulae 201 and 202 may include at least one of groups represented by Formulae CY201 to CY217:
R10b and R10c in Formulae CY201 to CY217 may each independently be the same as in the description of 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.
In embodiments, 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.
In an embodiment, the hole transport region may include one of Compounds HT1 to HT48, 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/camphorsulfonic acid (PANI/CSA), polyaniline/poly(4-styrenesulfonate (PANT/PSS), or any combination thereof:
In an embodiment, the electron blocking layer may include the hole transport host compound represented by Formula 2.
A thickness of the hole transport region may be in a range of about 50 Å to about 10,000 Å. For example, the thickness of the hole transport region may be in a range of about 100 Å to about 4,000 Å. When 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, the thickness of the hole transport region may be in a range of about 100 Å to about 1,000 Å. When the thicknesses of the hole transport region and the hole injection layer are within the ranges described above, satisfactory hole transport 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 lowest unoccupied molecular orbital (LUMO) energy level of the p-dopant may be equal to or less than about −3.5 eV.
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, etc.
Examples of the cyano group-containing compound may include HAT-CN, and a compound represented by Formula 221:
In Formula 221,
In an embodiment, the charge-generation material may be a p-dopant which may include, for example, any one of Compounds P1 to P6:
In the compound including element EL1 and element EL2, element EL1 may be a metal, a metalloid, or any combination thereof, and element EL2 may be a non-metal, a metalloid, or any combination thereof.
Examples of the metal may include: an alkali metal (for example, lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), etc.); 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 may include silicon (Si), antimony (Sb), and tellurium (Te).
Examples of the non-metal may include oxygen (O) and halogen (for example, F, Cl, Br, I, etc.).
Examples of the compound including element EL1 and element EL2 may include a metal oxide, a metal halide (for example, a metal fluoride, a metal chloride, a metal bromide, or a metal iodide), a metalloid halide (for example, a metalloid fluoride, a metalloid chloride, a metalloid bromide, or a metalloid iodide), a metal telluride, or any combination thereof.
Examples of the metal oxide may include a tungsten oxide (for example, WO, W2O3, WO2, WO3, W2O5, etc.), a vanadium oxide (for example, VO, V2O3, VO2, V2O5, etc.), a molybdenum oxide (MoO, Mo2O3, MoO2, MoO3, Mo2O5, etc.), and a rhenium oxide (for example, ReO3, etc.).
Examples of the metal halide may include an alkali metal halide, an alkaline earth metal halide, a transition metal halide, a post-transition metal halide, and a lanthanide metal halide.
Examples of the alkali metal halide 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 may include BeF2, MgF2, CaF2, SrF2, BaF2, BeCl2, MgCl2, CaCl2, SrCl2, BaCl2, BeBr2, MgBr2, CaBr2, SrBr2, BaBr2, BeI2, MgI2, CaI1, SrI2, and BaI2.
Examples of the transition metal halide may include a titanium halide (for example, TiF4, TiCl4, TiBr4, TiI4, etc.), a zirconium halide (for example, ZrF4, ZrCl4, ZrBr4, ZrI4, etc.), a hafnium halide (for example, Hf F4, HfCl4, HfBr4, HfI4, etc.), a vanadium halide (for example, VF3, VCl3, VBr3, VI3, etc.), a niobium halide (for example, NbF3, NbCl3, NbBr3, NbI3, etc.), a tantalum halide (for example, TaF3, TaCl3, TaBr3, TaI3, etc.), a chromium halide (for example, CrF3, CrCl3, CrBr3, CrI3, etc.), a molybdenum halide (for example, MoF3, MoCl3, MoBr3, MoI3, etc.), a tungsten halide (for example, WF3, WCl3, WBr3, WI3, etc.), a manganese halide (for example, MnF2, MnCl2, MnBr2, MnI2, etc.), a technetium halide (for example, TcF2, TcCl2, TcBr2, TcI2, etc.), a rhenium halide (for example, ReF2, ReCl2, ReBr2, ReI2, etc.), an iron halide (for example, FeF2, FeCl2, FeBr2, Felt, etc.), a ruthenium halide (for example, RuF2, RuCl2, RuBr2, Rule, etc.), an osmium halide (for example, OsF2, OsCl2, OsBr2, OsI2, etc.), a cobalt halide (for example, CoF2, CoCl2, CoBr2, CoI2, etc.), a rhodium halide (for example, RhF2, RhCl2, RhBr2, RhI2, etc.), an iridium halide (for example, IrF2, IrCl2, IrBr2, IrI2, etc.), a nickel halide (for example, NiF2, NiCl2, NiBr2, NiI2, etc.), a palladium halide (for example, PdF2, PdCl2, PdBr2, PdI2, etc.), a platinum halide (for example, PtF2, PtCl2, PtBr2, PtI2, etc.), a copper halide (for example, CuF, CuCl, CuBr, CuI, etc.), a silver halide (for example, AgF, AgCl, AgBr, AgI, etc.), and a gold halide (for example, AuF, AuCl, AuBr, AuI, etc.).
Examples of the post-transition metal halide may include a zinc halide (for example, ZnF2, ZnCl2, ZnBr2, ZnI2, etc.), an indium halide (for example, InI3, etc.), and a tin halide (for example, SnI2, etc.).
Examples of the lanthanide metal halide may include YbF, YbF2, YbF3, SmF3, YbCl, YbCl2, YbCl3 SmCl3, YbBr, YbBr2, YbBr3 SmBr3, YbI, YbI2, YbI3, and SmI3.
An example of the metalloid halide may be an antimony halide (for example, SbCl5, etc.).
Examples of the metal telluride may include an alkali metal telluride (for example, Li2Te, Na2Te, K2Te, Rb2Te, Cs2Te, etc.), an alkaline earth metal telluride (for example, BeTe, MgTe, CaTe, SrTe, BaTe, etc.), a 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.), a post-transition metal telluride (for example, ZnTe, etc.), and a 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]
When 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 sub-pixel. 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 may contact each other or may be separated from each other to emit white light. In embodiments, the emission layer may include two or more materials of a red light-emitting material, a green light-emitting material, and a blue light-emitting material, in which the two or more materials may be mixed with each other in a single layer to emit white light.
The emission layer may include a host and a dopant. The dopant may include a phosphorescent dopant.
An amount of the dopant in the emission layer may be in a range of about 0.01 parts by weight to about 15 parts by weight based on 100 parts by weight of the host, but embodiments are not limited thereto.
[Host]
Hole transport hosts and electron transport hosts may be the same as in the description above.
[Phosphorescent Dopant]
In embodiments, 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:
In Formulae 401 and 402,
In an embodiment, when xc1 in Formula 401 is 2 or more, two ring A401(s) among two or more of L401 may optionally be bonded to each other via T402, which may be a linking group, and two ring A402(s) among two or more of L401 may optionally be bonded to each other via T403, which may be a linking group (see Compounds PD1 to PD4 and PD7). T402 and T403 may each independently be the same as described herein with respect to 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, —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 PD40, or any combination thereof:
[Electron Transport Region in Interlayer 130]
The electron transport region may have a structure consisting of a layer consisting of a single material, a structure consisting of a layer including different materials, or a 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.
In an embodiment, the electron transport region may have an electron transport layer/electron injection layer structure or a hole blocking layer/electron transport layer/electron injection layer structure, wherein the layers of each structure may be stacked from the emission layer in its respective stated order, but the structure of the electron transport region is not limited thereto.
In an embodiment, 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:
[Ar601]xe11-[(L601)xe1-R601]xe21 [Formula 601]
In Formula 601,
In an embodiment, in Formula 601 when xe11 is 2 or more, two or more Ar601 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:
In Formula 601-1,
In an embodiment, in Formula 601 and 601-1, xe1 and xe611 to xe613 may each independently be 0, 1, or 2.
In an embodiment, the electron transport layer material included in the electron transport layer may include a compound represented by Formula 601, a compound represented by Formula 601-1, or any combination thereof.
In an embodiment, the compound represented by Formulae 601 and 601-1 may include at least one deuterium. In an embodiment, all hydrogen included in the compound represented by Formulae 601 and 601-1 may be substituted with deuterium.
The electron transport region may include one of Compounds ET1 to ET47, 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:
In an embodiment, the hole blocking layer may include the electron transport host compound represented by Formula 1. When hole blocking layer includes the electron transport host compound represented by Formula 1, there may be no need for the electron mobility of the compound to be less than 1×10−8 cm2/Vs.
A thickness of the electron transport region may be in a range of about 100 Å to about 5,000 Å. For example, the thickness of the electron transport region may be in a range of about 160 Å to about 4,000 Å.
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.
When the electron transport layer includes an electron transport layer material and a metal-containing material, the weight ratio of the electron transport layer material to the metal-containing material may be in a range of about 9:1 to about 1:9. In an embodiment, a weight ratio of the electron transport layer material to the metal-containing material may be in a range of about 7:3 to about 3:7. In an embodiment, a weight ratio of the electron transport layer material to the metal-containing material may be in a range of about 6:4 to about 4:6. When the weight ratio of the electron transport layer material to the metal-containing material is within the above range, the light-emitting device may have excellent driving voltage and lifespan.
The metal-containing material may include an alkali metal complex, an alkaline earth metal complex, or any combination thereof. The metal ion of an alkali metal complex may be a Li ion, a Na ion, a K ion, a Rb ion, or a Cs ion, and the metal ion of an 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 a hydroxyquinoline, a hydroxyisoquinoline, a hydroxybenzoquinoline, a hydroxyacridine, a hydroxyphenanthridine, a hydroxyphenyloxazole, a hydroxyphenylthiazole, a hydroxyphenyloxadiazole, a hydroxyphenylthiadiazole, a hydroxyphenylpyridine, a hydroxyphenylbenzimidazole, a hydroxyphenylbenzothiazole, a bipyridine, a phenanthroline, a 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 Compound 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 contact (e.g., directly contact) the second electrode 150.
The electron injection layer may have a structure consisting of a layer consisting of a single material, a structure consisting of a layer including different materials, or a 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 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 may be oxides, halides (for example, fluorides, chlorides, bromides, or iodides), or tellurides of the alkali metal, the alkaline earth metal, and the rare earth metal, or any combination thereof.
The alkali metal-containing compound 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 may include an alkaline earth metal compound, such as BaO, SrO, CaO, BaxSr1-xO (wherein x may be a real number satisfying the condition of 0<x<1), BaxCa1-xO (wherein x may be a real number satisfying the condition of 0<x<1), or the like. The rare earth metal-containing compound may include YbF3, ScF3, Sc2O3, Y2O3, Ce2O3, GdF3, TbF3, YbI3, ScI3, TbI3, or any combination thereof. In embodiments, the rare earth metal-containing compound may include a 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 may include one of ions of the alkali metal, the alkaline earth metal, and the rare earth metal and, as a ligand bonded to the metal ion, for example, a hydroxyquinoline, a hydroxyisoquinoline, a hydroxybenzoquinoline, a hydroxyacridine, a hydroxyphenanthridine, a hydroxyphenyloxazole, a hydroxyphenylthiazole, a hydroxyphenyloxadiazole, a hydroxyphenylthiadiazole, a hydroxyphenylpyridine, a hydroxyphenyl benzimidazole, a hydroxyphenylbenzothiazole, a bipyridine, a phenanthroline, a 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 herein. In embodiments, the electron injection layer may further include an organic material (for example, a compound represented by Formula 601).
In embodiments, the electron injection layer may consist of: an alkali metal-containing compound (for example, an alkali metal halide); or an alkali metal-containing compound (for example, an alkali metal halide), and 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.
When 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, the thickness of the electron injection layer may be in a range of about 3 Å to about 90 Å. When the thickness of the electron injection layer is within the ranges 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 located on the interlayer 130 having a structure as described above. The second electrode 150 may be a cathode, which is an electron injection electrode. A material for forming the second electrode 150 may include a metal, an alloy, an electrically conductive compound, or any combination thereof, each having a low-work function.
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.
[Capping Layer]
The light emitting device 10 may include a first capping layer located outside the first electrode 110, and/or a second capping layer located outside the second electrode 150. For example, 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 stacked in this stated order, a structure in which the first electrode 110, the interlayer 130, the second electrode 150, and the second capping layer are stacked in this 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 stacked in the stated order.
Light generated in an emission layer of the interlayer 130 of the light-emitting device 10 may be extracted toward the outside through the first electrode 110 which may be a semi-transmissive electrode or a transmissive electrode, and the first capping layer. Light generated in an emission layer of the interlayer 130 of the light-emitting device 10 may be extracted toward the outside through the second electrode 150 which may be a semi-transmissive electrode or a transmissive electrode, and the second capping layer.
The first capping layer and the second capping layer may each increase external emission efficiency according to the principle of constructive interference. Accordingly, the light extraction 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 equal to or greater than about 1.6 (with respect to a wavelength of about 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 carbocyclic compounds, heterocyclic compounds, amine group-containing compounds, porphine derivatives, phthalocyanine derivatives, naphthalocyanine derivatives, alkali metal complexes, alkaline earth metal complexes, or any combination thereof. Optionally, the carbocyclic compound, the heterocyclic compound, and the amine group-containing compound may be substituted with a substituent including O, N, S, Se, Si, F, Cl, Br, I, or any combination thereof. In embodiments, 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, a color filter, a color conversion layer, or a color filter and a color conversion layer. The color filter and/or the color conversion layer may be located in at least one direction in which light emitted from the light-emitting device travels. For example, the light emitted from the light-emitting device may be blue light. The light-emitting device, may be the same as described herein. In embodiments, the color conversion layer may include a quantum dot.
The electronic apparatus may include a first substrate. The first substrate may include subpixels, the color filter may include color filter areas respectively corresponding to the subpixels, and the color conversion layer may include color conversion areas respectively corresponding to the subpixels.
A pixel-defining film may be located among the subpixels to define each subpixel.
The color filter may further include color filter areas and light-shielding patterns located between the color filter areas, and the color conversion layer may further include 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, wherein the first color light, the second color light, and/or the third color light may have different maximum emission wavelengths from one another. 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. The first area may include a red quantum dot, the second area may include a green quantum dot, and the third area may not include a quantum dot. The quantum dot may be the same as described herein. The first area, the second area, and/or the third area may each 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. The first-first color light, the second-first color light, and the third-first color light may have different maximum emission wavelengths. 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 herein. The thin-film transistor may include a source electrode, a drain electrode, and an activation layer, wherein any one of the source electrode and the drain electrode may be electrically connected to any 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, or the like.
The activation layer may include crystalline silicon, amorphous silicon, an organic semiconductor, an oxide semiconductor, or 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 allows light from the light-emitting device to be extracted 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. When the sealing portion is a thin film encapsulation layer, the electronic apparatus may be flexible.
Various functional layers may be further included 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.
An 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 herein, 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 located 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.
A TFT may be located 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 located on the activation layer 220, and the gate electrode 240 may be located on the gate insulating film 230.
An interlayer insulating film 250 may be located on the gate electrode 240. The interlayer insulating film 250 may be located between the gate electrode 240 and the source electrode 260 to insulate the gate electrode 240 from the source electrode 250 and between the gate electrode 240 and the drain electrode 270, to insulate the gate electrode 240 from the drain electrode 270.
The source electrode 260 and the drain electrode 270 may be located 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 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 located on the passivation layer 280. The passivation layer 280 may be located to expose a portion of the drain electrode 270, not fully covering the drain electrode 270, and the first electrode 110 may be electrically connected to the exposed portion of the drain electrode 270.
A pixel defining layer 290 including an insulating material may be located on the first electrode 110. The pixel defining layer 290 may expose a certain region of the first electrode 110, and an 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 located on the interlayer 130, and a capping layer 170 may be further included on the second electrode 150. The capping layer 170 may be formed to cover the second electrode 150.
The encapsulation portion 300 may be located on the capping layer 170. The encapsulation portion 300 may be located 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, or the like), an epoxy-based resin (for example, aliphatic glycidyl ether (AGE), or the like), or any combination thereof; or any combination of the inorganic films and the organic films.
The electronic apparatus of
[Description of
The electronic device 1 may include a display area DA and a non-display area NDA outside the display area DA. The electronic device 1 may implement an image through an array of pixels that may be two-dimensionally arranged in the display area DA.
The non-display area NDA may be an area that does not display an image, and may entirely surround the display area DA. On the non-display area NDA, a driver for providing electrical signals or power to display elements and the like (for example, pixels) arranged on the display area DA may be arranged. On the non-display area NDA, a pad, which may be an area to which an electronic element or a printing circuit board may be electrically connected, may be arranged.
In the electronic device 1, a length in the x-axis direction and a length in the y-axis direction may be different from each other. In an embodiment, as shown in
[Descriptions of
Referring to
The vehicle 1000 may travel on a road or a track. The vehicle 1000 may move in a given direction according to the rotation of at least one wheel. For example, the vehicle 1000 may be a three-wheeled or four-wheeled vehicle, a construction machine, a two-wheeled vehicle, a prime mover device, a bicycle, or a train running on a track.
The vehicle 1000 may include a body having an interior and an exterior, and a chassis in which mechanical apparatuses necessary for driving may be installed as other parts excluding the body. The exterior of the vehicle body may include a front panel, a bonnet, a roof panel, a rear panel, a trunk, a filler provided at a boundary between doors, and the like. The chassis of the vehicle 1000 may include a power generating device, a power transmitting device, a driving device, a steering device, a braking device, a suspension device, a transmission device, a fuel device, front and rear wheels, left and right wheels, and the like.
The vehicle 1000 may include a side window glass 1100, a front window glass 1200, a side mirror 1300, a cluster 1400, a center fascia 1500, a passenger seat dashboard 1600, and a display device 2.
The side window glass 1100 and the front window glass 1200 may be partitioned by a filler arranged between the side window glass 1100 and the front window glass 1200.
The side window glass 1100 may be installed on the side of the vehicle 1000. In an embodiment, the side window glass 1100 may be installed on a door of the vehicle 1000. Multiple side window glasses 1100 may be provided and may face each other. In an embodiment, the side window glass 1100 may include a first side window glass 1110 and a second side window glass 1120. In an embodiment, the first side window glass 1110 may be arranged adjacent to the cluster 1400. The second side window glass 1120 may be arranged adjacent to the passenger seat dashboard 1600.
In an embodiment, the side window glasses 1100 may be spaced apart from each other in the x-direction or the −x-direction. For example, the first side window glass 1110 and the second side window glass 1120 may be spaced apart from each other in the x direction or the −x direction. An imaginary straight line L connecting the side window glasses 1100 may extend in the x-direction or the −x-direction. For example, an imaginary straight line L connecting the first side window glass 1110 and the second side window glass 1120 to each other may extend in the x direction or the −x direction.
The front window glass 1200 may be installed on the front of the vehicle 1000. The front window glass 1200 may be arranged between the side window glasses 1100 facing each other.
The side mirror 1300 may provide a rear view of the vehicle 1000. The side mirror 1300 may be installed on the exterior of the vehicle body. In an embodiment, multiple side mirrors 1300 may be provided. Any one of the side mirrors 1300 may be arranged outside the first side window glass 1110. Another one of the side mirrors 1300 may be arranged outside the second side window glass 1120.
The cluster 1400 may be arranged in front of a steering wheel. The cluster 1400 may include a tachometer, a speedometer, a coolant thermometer, a fuel gauge, a turn signal indicator, a high beam indicator, a warning light, a seat belt warning light, an odometer, a driving record system, an automatic transmission selection lever indicator, a door open warning light, an engine oil warning light, and/or a fuel shortage warning light.
The center fascia 1500 may include a control panel on which buttons may be provided for adjusting an audio device, an air conditioning device, and a heater of a seat. The center fascia 1500 may be arranged on one side of the cluster 1400.
A passenger seat dashboard 1600 may be spaced apart from the cluster 1400 with the center fascia 1500 therebetween. In an embodiment, the cluster 1400 may be arranged to correspond to a driver seat (not shown), and the passenger seat dashboard 1600 may be disposed to correspond to a passenger seat (not shown). In an embodiment, the cluster 1400 may be adjacent to the first side window glass 1110, and the passenger seat dashboard 1600 may be adjacent to the second side window glass 1120.
In an embodiment, the display device 2 may include a display panel 3, and the display panel 3 may display an image. The display device 2 may be arranged inside the vehicle 1000. In an embodiment, the display device 2 may be arranged between the side window glasses 1100 facing each other. The display device 2 may be arranged in at least one of the cluster 1400, the center fascia 1500, and the passenger seat dashboard 1600.
The display device 2 may include an organic light-emitting display device, an inorganic electroluminescent (EL) display device, a quantum dot display device, and the like. Although an organic light-emitting display device display including the light-emitting device according to embodiments is described as an example, various types of display devices as described herein may be used in embodiments, but embodiments are not limited thereto.
Referring to
Referring to
Referring to
[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 suitable methods selected from vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) deposition, ink-jet printing, laser-printing, and laser-induced thermal imaging.
When layers constituting the hole transport region, an emission layer, and layers constituting the electron transport region are formed by vacuum deposition, the deposition may be performed at a deposition temperature in a range of about 100° C. to about 500° C., a vacuum degree in a range of about 10−8 torr to about 10−3 torr, and a deposition speed in a range of about 0.01 Å/sec to about 100 Å/sec, depending on a material to be included in a layer to be formed and the structure of a layer to be formed.
When layers constituting the hole transport region, an emission layer, and layers constituting the electron transport region are formed by spin coating, the spin coating may be performed at a coating speed in a range of about 2,000 rpm to about rpm and at a heat treatment temperature in a range 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.
The term “C3-C60 carbocyclic group” as used herein may be a cyclic group consisting of carbon only as ring-forming atoms and having three to sixty carbon atoms, and the term “C1-C60 heterocyclic group” as used herein may be a cyclic group that has one to sixty 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 the C3-C60 carbocyclic group, or the C1-C60 heterocyclic group.
The term “π electron-rich C3-C60 cyclic group” as used herein may be a cyclic group that has three to sixty carbon atoms and may not include *—N═*′ as a ring-forming moiety, and the term “π electron-deficient nitrogen-containing C1-C60 cyclic group” as used herein may be a heterocyclic group that has one to sixty carbon atoms and includes *—N═*′ as a ring-forming moiety.
In embodiments,
The terms “cyclic group”, “C3-C60 carbocyclic group”, “C1-C60 heterocyclic group”, “π electron-rich C3-C60 cyclic group”, or “π electron-deficient nitrogen-containing C1-C60 cyclic group” as used herein may each 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 may be 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-C10 heterocycloalkyl group, a C3-C10 cycloalkenyl group, a C1-C10 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-C10 heterocycloalkylene group, a C3-C10 cycloalkenylene group, a C1-C10 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 one to sixty 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 a 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 a 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 a same structure as the C2-C60 alkynyl group.
The term “C1-C60 alkoxy group” as used herein may be a monovalent group represented by —O(A101) (wherein A101 may be the C1-C60 alkyl group), and examples thereof 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 a same structure as the C3-C10 cycloalkyl group.
The term “C1-C10 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 may include a 1,2,3,4-oxatriazolidinyl group, a tetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term “C1-C10 heterocycloalkylene group” as used herein may be a divalent group having a same structure as the C1-C10 heterocycloalkyl group.
The term C3-C10 cycloalkenyl group used herein may be a monovalent cyclic group that has three to ten 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 a 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 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 a 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 may 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. When the C6-C60 aryl group and the C6-C60 arylene group each include two or more rings, the respective 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. When the C1-C60 heteroaryl group and the C1-C60 heteroarylene group each include two or more rings, the respective 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 indeno anthracenyl group. The term “divalent non-aromatic condensed polycyclic group” as used herein may be a divalent group having a same structure as the monovalent non-aromatic condensed polycyclic group described above.
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 naphtho indolyl 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 indenocarbazolyl 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 benzonaphthosilolyl 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 a same structure as the monovalent non-aromatic condensed heteropolycyclic group described above.
The term “C6-C60 aryloxy group” as used herein may be a group represented by —O(A102) (wherein A102 may be the C6-C60 aryl group), and the term “C6-C60 arylthio group” as used herein indicates —SA103 (wherein A103 may be the C6-C60 aryl group).
The term “C7-C60 arylalkyl group” used herein may be a group represented by -(A104)(A105) (wherein A104 may be a C1-C54 alkylene group, and A105 may be a C6-C59 aryl group), and the term “C2-C60 heteroarylalkyl group” used herein may be a group represented by -(A106)(A107) (wherein A106 may be a C1-C59 alkylene group, and A107 may be a C1-C59 heteroaryl group).
The group “R10a” as used herein may be:
In the specification, Q1 to Q3, Q11 to Q13, Q21 to Q23, and Q31 to Q33 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; or a C1-C60 alkoxy group; or
The term “heteroatom” as used herein refers to any atom other than a carbon atom or a hydrogen 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), etc.
The term “Ph” as used herein refers to a phenyl group, the term “Me” as used herein refers to a methyl group, the term “Et” as used herein refers to an ethyl group, the terms “ter-Bu” or “But” as used herein each refer to a tert-butyl group, and the term “OMe” as used herein refers to a methoxy group.
The term “biphenyl group” as used herein may be a “phenyl group substituted with a phenyl group.” For example, 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”. For example, 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 may be an example only. In an embodiment, the maximum carbon number of 60 in the C1-C60 alkyl group may be an example, and the definition of the alkyl group may be equally applied to a C1-C20 alkyl group. The same applies to other cases.
The symbols * and *′ as used herein, unless defined otherwise, each refer to 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 300 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 loaded onto a vacuum deposition apparatus.
Compound HTL1 and a p-dopant P4 were deposited on the substrate to form a hole injection layer having a thickness of 100 Å (doping: 2 wt %).
Compound HTL1 was deposited thereon to form a hole transport layer having a thickness of 1,000 Å.
Compound HTH1 was vacuum-deposited thereon to form an electron blocking layer having a thickness of 100 Å.
Compound HTH1 as a hole transport host, Compound ETH1 as an electron transport host (weight ratio of 5:5), and PD40 as a phosphorescent dopant were deposited on the electron blocking layer to form an emission layer having a thickness of 400 Å (doping: 10 v %).
Compound ETH1 was vacuum-deposited thereon to form a hole blocking layer having a thickness of 100 Å.
ETL1 and LiQ were deposited at a weight ratio of 5:5 on the hole blocking layer to form an electron transport layer having a thickness of 300 Å.
LiF was vacuum-deposited on the electron transport layer to form an electron injection layer having a thickness of 10 Å, and Ag was vacuum-deposited thereon to form a cathode having a thickness of 120 Å, and CP1 was deposited thereon to form a capping layer having a thickness of 800 Å, thereby completing the manufacture of a light-emitting device.
Light-emitting devices of Comparative Examples 2 to 6 were manufactured in the same manner as in manufacturing Comparative Example 1, except that the compounds of Table 1 were used to form a hole transport layer, an emission layer, and an electron transport layer.
Light-emitting devices of Examples 1 to 5 were manufactured in the same manner as in manufacturing Comparative Example 1, except that the compounds of Table 2 were used to form a hole transport layer, an emission layer, and an electron transport layer.
Regarding the electron mobility of the material used in the hole transport layer, the electron mobility of the hole transport host, the electron mobility of the electron transport host, and the electron mobility of the electron transport layer used in the emission layer of the devices of Comparative Example and Example, current density according to voltage were measured with Keithley 2635B[Nubicom], mobility was calculated using a space-charge-limited-current (SCLC) analysis method, and results thereof are shown in Table 3 (details of the SCLC analysis are omitted).
In Table 3, because the hole transport layer of the devices of Comparative Examples and Examples include one type of material, the electron mobility of the hole transport layer material may be the electron mobility of the hole transport layer.
To evaluate the characteristics of the light-emitting devices manufactured according to the Comparative Examples and the Examples, the driving voltage, efficiency, and lifespan thereof were measured, and results thereof are shown in Table 4.
The driving voltage, efficiency, and lifespan of the light-emitting devices were measured by using a measurement device C9920-2-12 of Hamamatsu Photonics Inc.
From Table 1, it was confirmed that the light-emitting devices of Examples have lower driving voltage and excellent lifespan compared to those of Comparative Examples.
In this regard, it may be determined that, in the light-emitting device according to an embodiment, the charge amount and exciton amount in the device were harmoniously adjusted by setting the hole mobility of the hole transport layer to be greater than 1×10−4 cm2/Vs, the electron mobility of the electron transport layer to be greater than 1×10−8 cm2/Vs, and the electron mobility of the electron transport host compound to be less than 1×10−8 cm2/Vs.
As described above, according to embodiments, a light-emitting device may exhibit low driving voltage and improved lifespan, as compared with devices in the related art.
Embodiments have been disclosed herein, and although terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. In some instances, as would be apparent by one of ordinary skill in the art, features, characteristics, and/or elements described in connection with an embodiment may be used singly or in combination with features, characteristics, and/or elements described in connection with other embodiments unless otherwise specifically indicated. Accordingly, it will be understood by those of ordinary skill in the art that various changes in form and details may be made without departing from the spirit and scope of the disclosure as set forth in the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2022-0079994 | Jun 2022 | KR | national |
