Patent Application
20230209852
This application claims priority to and the benefit of Korean Patent Application No. 10-2021-0186588, filed on Dec. 23, 2021, in the Korean Intellectual Property Office, the entire content of which is hereby incorporated by reference herein.
Aspects of one or more embodiments of the present disclosure relate to a light-emitting device and an electronic apparatus including the same.
Self-emissive devices among light-emitting devices have wide viewing angles, high contrast ratios, short response times, and excellent or suitable characteristics in terms of luminance, driving voltage, and response speed.
In a light-emitting device, a first electrode is on a substrate, and a hole transport region, an emission layer, an electron transport region, and a second electrode are sequentially disposed 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 excitons. These excitons are transitioned from an excited state to a ground state to thereby generate light.
Aspects of one or more embodiments of the present disclosure are directed toward a light-emitting device and an electronic apparatus including the same.
Additional aspects of embodiments of the present disclosure will be set forth in part in the disclosure which follows and, in part, will be apparent from the disclosure, or may be learned by practice of the presented embodiments of the disclosure.
According to one or more embodiments, a light-emitting device includes
According to one or more embodiments, an electronic apparatus includes the light-emitting device.
The above and other aspects and features of certain embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:
Reference will now be made in more detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout, and duplicative descriptions thereof may not be provided. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described, by referring to the drawings, to explain aspects of embodiments of the present disclosure. As utilized herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Throughout the disclosure, the expression “at least one of a, b and c” indicates only a, only b, only c, both (e.g., simultaneously) a and b, both (e.g., simultaneously) a and c, both (e.g., simultaneously) b and c, all of a, b, and c, or variations thereof.
An aspect of embodiments of the present disclosure is directed to a light-emitting device including: a first electrode; a second electrode facing the first electrode; and an interlayer arranged between the first electrode and the second electrode and including an emission layer, wherein the emission layer includes a first emission layer and a second emission layer, the first emission layer includes a first host including a first-first host and a first-second host, and does not include a dopant (e.g., does not include the dopant of the second emission laye or does not include any dopant), the second emission layer includes a second host and a dopant, the second host including a second-first host and a second-second host, the first-first host and the first-second host are different from each other, the second-first host and the second-second host are different from each other, a triplet energy level of the first host (TH1) is greater than a triplet energy level of the second host (TH2).
The triplet energy level of the first host TH1 may refer to the triplet energy level of a host mixture (e.g., a first host mixture) including both (e.g., simultaneously) the first-first host and the first-second host.
The triplet energy level of the second host TH2 may refer to the triplet energy level of a host mixture (e.g., a second host mixture) including both (e.g., simultaneously) the second-first host and the second-second host.
For example, the triplet energy level of the first host TH1 may be calculated from the starting point of the shortest wavelength from a low-temperature emission spectrum of a mixed deposition layer formed by the first-first host and the first-second host (250 Å + 250 Å).
For example, the triplet energy level of the second host TH2 may be calculated from the starting point of the shortest wavelength from a low-temperature emission spectrum of a mixed deposition layer formed by the second-first host and the second-second host (250 Å + 250 Å).
In an embodiment, triplet excitons formed in the first emission layer may migrate from the first emission layer to the second emission layer. For example, when the triplet energy level of the first host TH1 is greater than the triplet energy level of the second host TH2, the triplet excitons formed in the first emission layer may migrate from the first emission layer to the second emission layer. For example, when the triplet excitons formed in the first emission layer migrate to the second emission layer, the triplet excitons may be converted into an emission energy of the dopant included in the second emission layer.
In an embodiment, migration of triplet excitons formed in the second emission layer from the second emission layer to the first emission layer may be limited. For example, when the triplet energy level of the second host TH2 is greater than the triplet energy level of the first host TH1, the migration of the triplet excitons formed in the second emission layer from the second emission layer to the first emission layer may be limited.
In an embodiment, the first-first host, the first-second host, the second-first host, and the second-second host may each independently be represented by Formula 1:
[0031] wherein, in Formula 1,
In an embodiment, an electron-transporting moiety may be included in: one selected from the first-first host and the first-second host; and one selected from the second-first host and the second-second host.
In one or more embodiments, the electron-transporting moiety may be included in the first-second host and the second-second host.
In an embodiment, the electron-transporting moiety may include a cyano group, a fluorine, a π-electron deficient nitrogen-containing C1-C60 cyclic group, or one or more combinations thereof.
For example, the π-electron deficient nitrogen-containing C1-C60 cyclic group may include a heterocyclic group including at least one *—N═*’ moiety as a ring-forming moiety.
In an embodiment, the first-first host and the second-first host may each be a hole-transporting host, and the first-second host and the second-second host may each be an electron-transport host.
For example, the hole-transporting host may include at least one of Compound 1-1 and Compound 1-2:
For example, the electron-transporting host may include at least one of Compound 2-1, Compound 2-2, and Compound 2-3:
In an embodiment, the first-first host and the second-first host may be identical to each other, and the first-second host and the second-second host may be different from each other.
In one or more embodiments, the first-first host and the second-first host may be different from each other, and the first-second host and the second-second host may be identical to each other.
In one or more embodiments, the first-first host and the second-first host may be different from each other, and the first-second host and the second-second host may be also different from each other.
In an embodiment, an amount ratio of the first-second host to the first-first host included in the first host may be in a range of about 1:0.1 to about 1:10. For example, the amount ratio of the first-second host to the first-first host included in the first host may be in a range of about 1:0.5 to about 1:2.
In an embodiment, an amount ratio of the second-second host to the second-first host included in the second host may be in a range of about 1:0.1 to about 1:10. For example, the amount ratio of the second-second host to the second-first host included in the second host may be in a range of about 1:0.5 to about 1:2.
In an embodiment, the dopant may be a phosphorescent dopant.
In an embodiment, the dopant may be represented by Formula 3:
In Formulae 3 and 3a, M3 may be 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).
In an embodiment, in Formula 3, M3 may be Ir or Pt. In an embodiment, in Formula 3, M3 may be Pt.
In Formula 3, L31 may be a ligand represented by Formula 3a.
In Formula 3, a31 may be an integer from 1 to 3. Here, a31 indicates the number of L31(s). When a31 is an integer of 2 or greater, two or more of L31 may be identical to or different from each other.
In Formulae 3 and 3a, when a31 is 2 or more, two ring CY31(s) in two or more of L31(s) may optionally be linked to each other via T32, which is a linking group, or two ring CY32(s) in two or more of L31(s) may optionally be linked to each other via T33, which is a linking group.
In Formula 3, L32 may be an organic ligand.
In an embodiment, the organic ligand may include a halogen group, a diketone group, a carboxylic acid group, —C(═O) group, an isonitrile group, a —CN group, a phosphorus containg group, or one or more combinations thereof.
In Formula 3, a32 may be an integer from 1 to 3. Here, a32 indicates the number of L32(s). When a32 is an integer of 2 or greater, two or more of L32 may be identical to or different from each other.
In Formula 3a, X31 and X32 may each independently be nitrogen or carbon.
In an embodiment, X31 and X32 in Formula 3a may satisfy one of Conditions 3-1 to 3-3:
In an embodiment, X31 and X32 in Formula 3a may satisfy Condition 3-1 or Condition 3-2.
In Formula 3a, ring CY31 and ring CY32 may each independently be a C3-C60 carbocyclic group or a C1-C60 heterocyclic group.
In an embodiment, in Formula 3a, ring CY31 and ring CY32 may each independently be a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, an imidazole group, a pyrazole group, a pyridine group, a pyrimidine group, a pyridoindole group, a benzimidazole group, a carbazole group, a dibenzofuran group, a fluorene group, a dibenzothiophene group, or a dibenzosilole group.
In one or more embodiments, in Formula 3a, ring CY31 and ring CY32 may each independently be a benzene group, an imidazole group, a pyrazole group, a pyridine group, a pyrimidine group, a pyridoindole group, a benzimidazole group, or a carbazole group.
In Formula 3a, T31 to T33 may each independently be a single bond, *“—O—*”’, *“—S—*’”, *“—C(═O)—*”’, *“—N(Z31)—*”’, *“—C(Z31)(Z32)—*’”, *“—C(Z31)═C(Z32)—*”’, *“—C(Z31)═*”’, or *“═C═*”’, wherein *” and *”’ each indicate a binding site to a neighboring atom.
X33 and X34 may each independently be a covalent bond, a coordinate bond, O, S, N(Z33), B(Z33), P(Z33), C(Z33)(Z34), or Si(Z33)(Z34).
*” and *’” each indicate a binding site to a neighboring atom.
In an embodiment, in Formula 3a, T31 to T33 may each independently be a single bond or *“—O—*”’.
In Formula 3a, R31, R32, and Z31 to Z34 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(Q1)(Q2)(Q3), —N(Q1)(Q2), —B(Q1)(Q2), —C(═O)(Q1), —S(═O)2(Q1), or —P(═O)(Q1)(Q2).
In Formula 3a, b31 and b32 may each independently be an integer from 0 to 10.
b31 and b32 indicate the number of R31(s) and the number of R32(s), respectively. When b31 is an integer of 2 or greater, two or more of R31(s) may be identical to or different from each other. When b32 is an integer of 2 or greater, two or more of R32(s) may be identical to or different from each other.
Two R31(s) among two or more of R31(s) when b31 is an integer of 2 or more; two R32(s) among two or more of R32(s) when b32 is an integer of 2 or more; or R31 and R32, may optionally be linked to each other to form 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 Formula 3a, * and *’ each indicate a binding site to M3 in Formula 3.
In Formulae 3 and 3a, R10a may be: deuterium, -F, -Cl, -Br, -I, a hydroxyl group, a cyano group, or a nitro group;
For example, the dopant may include at least one of Compounds 3-1 and 3-2:
In the light-emitting device, the emission layer may include the first emission layer and the second emission layer. The first emission layer may include the first host including the first-first host and the first-second host, and may not include (e.g., may exclude) a dopant (e.g., may not include any dopant or the dopant of the second emission layer). The second emission layer may include the second host and the dopant, the second host including the second-first host and the second-second host. Here, the first-first host and the first-second host may be different from each other, and the second-first host and the second-second host may be different from each other. The triplet energy level of the first host TH1 may be greater than the triplet energy level of the second host TH2.
Although not intended to be limited by a particular theory, in the light-emitting device disclosed herein, the first host included in the first emission layer and the second host included in the second emission layer satisfy a specific condition regarding the triplet energy level, and thus the triplet excitons formed in the first emission layer may easily migrate to the second emission layer. In some embodiments, the migration of the triplet excitons formed in the second emission layer to the first emission layer may be suppressed or reduced.
Thus, an additional reaction, such as a triplet-triplet or triplet-polaron interaction may be prevented or reduced, thereby improving (increasing) a lifespan of the light-emitting device. In some embodiments, the excitons formed in the first emission layer may migrate to the second emission layer, and then may be converted into the emission energy of the dopant included in the second emission layer, thereby improving efficiency of the light-emitting device. Accordingly, an electronic apparatus including the light-emitting device may have improved (increased) luminescence efficiency and/or a long lifespan.
Synthesis methods of the compound represented by Formula 1 and the compound represented by Formula 3 may be recognized by those of ordinary skill in the art by referring to Examples described herein.
In an embodiment, the light-emitting device may include:
In an embodiment,
The hole transport region may include a hole injection layer, a hole transport layer, an emission auxiliary layer, an electron blocking layer, or one or more combinations thereof.
The electron transport region may include a buffer layer, a hole blocking layer, an electron control layer, an electron transport layer, an electron injection layer, or one or more combinations thereof.
In an embodiment, the light-emitting device may satisfy Condition 1 or Condition 2:
Condition 1
Condition 2
In an embodiment, the light-emitting device may satisfy Condition 1. In an embodiment, the light-emitting device may satisfy Condition 2.
In one or more embodiments, the light-emitting device may include a plurality of first emission layers, and may satisfy both (e.g., simultaneously) Conditions 1 and 2.
In an embodiment, the light-emitting device may satisfy Condition 1-1 or Condition 2-1:
the first emission layer is arranged between the hole transport region and the second emission layer, and the second emission layer is arranged between the electron transport region and the first emission layer; and
the first emission layer is arranged between the electron transport region and the second emission layer, and the second emission layer is arranged between the hole transport region and the first emission layer.
In an embodiment, the light-emitting device may satisfy Condition 1-1. In an embodiment, the light-emitting device may satisfy Condition 2-1.
In one or more embodiments, the light-emitting device may include a plurality of first emission layers, and may satisfy both (e.g., simultaneously) Conditions 1-1 and 2-1.
In an embodiment, the light-emitting device may satisfy Condition 1-2 or Condition 2-2:
the first emission layer is arranged between the electron blocking layer and the second emission layer, and the second emission layer is arranged between the hole blocking layer and the first emission layer; and
the first emission layer is arranged between the hole blocking layer and the second emission layer, and the second emission layer is arranged between the electron blocking layer and the first emission layer.
In an embodiment, the light-emitting device may satisfy Condition 1-2. In an embodiment, the light-emitting device may satisfy Condition 2-2.
In one or more embodiments, the light-emitting device may include a plurality of first emission layers, and may satisfy both (e.g., simultaneously) Conditions 1-2 and 2-2.
In an embodiment, the first emission layer may be in direct contact with the second emission layer.
In an embodiment, triplet excitons formed in the first emission layer may migrate from the first emission layer to the second emission layer.
In one or more embodiments, the migration of triplet excitons formed in the second emission layer from the second emission layer to the first emission layer may be limited.
In an embodiment, the emission layer may emit red light, green light, blue light, and/or white light.
For example, the emission layer may emit blue light. The blue light may have, for example, a maximum emission wavelength in a range of about 400 nm to about 490 nm. The blue light may have, for example, a maximum emission wavelength in a range of, for example, about 440 nm to about 480 nm.
In an embodiment, the second emission layer may emit red light, green light, blue light, and/or white light.
For example, the second emission layer may emit blue light. The blue light may have, for example, a maximum emission wavelength in a range of about 400 nm to about 490 nm. The blue light may have, for example, a maximum emission wavelength in a range of, for example, about 440 nm to about 480 nm.
For example, the first emission layer may further include another host in addition to the first host. For example, the second emission layer may further include another host, in addition to the second host.
In one or more embodiments, the emission layer may further include a dopant. In an embodiment, the dopant may further include a phosphorescent dopant, a delayed fluorescence material, or a combination thereof. For example, the emission layer may further include a phosphorescent dopant, in addition to a host and a dopant represented by Formula 3. However, the first emission layer may not include (e.g., may exclude) the dopant (e.g., does not include any dopant). For example, the first emission layer may not include (e.g., may exclude) a phosphorescent dopant, a delayed fluorescence material, or any combination thereof.
In one or more embodiments, the second emission layer may further include a dopant. In an embodiment, the dopant may further include a phosphorescent dopant, a delayed fluorescence material, or any combination thereof. For example, the second emission layer may further include a dopant, in addition to a host and a dopant represented by Formula 3.
For example, the dopant may include a transition metal and ligand(s) in the number of m, wherein m may be an integer from 1 to 6. The ligand(s) in the number of m may be identical to or different from each other, at least one of the ligand(s) in the number of m may be linked to the transition metal via a carbon-transition metal bond, and the carbon-transition metal bond may be a coordinate bond. For example, at least one of the ligand(s) in the number of m may be a carbene ligand (for example, lr(pmp)3 and/or the like). The transition metal may be, for example, Ir,Pt, Os, Pd, Rh, or Au. The emission layer and the dopant may be the same as described in the present disclosure.
In one or more embodiments, the light-emitting device may include a capping layer arranged outside the first electrode or outside the second electrode.
For example, the light-emitting device may further include at least one selected from a first capping layer arranged outside the first electrode and a second capping layer arranged outside the second electrode. More details on the first capping layer and/or second capping layer may each independently be the same as described in the present disclosure.
The expression “(interlayer and/or electron transport layer) includes a compound represented by Formula 1” as utilized herein may be understood as “(interlayer and/or electron transport layer) may include one kind of compound represented by Formula 1 or two or morekinds of compounds, each represented by Formula 1.”
For example, the first emission layer may include the first host. For example, the first emission layer may include the first-first host and the first-second host. For example, the second emission layer may include the second host. For example, the second emission layer may include the second-first host and the second-second host.
The term “interlayer” as utilized herein refers to a single layer and/or all of a plurality of layers arranged between the first electrode and the second electrode of the light-emitting device.
Another aspect of embodiments provides an electronic apparatus including the light-emitting device. The electronic apparatus may further include a thin-film transistor. For example, the electronic apparatus may further include a thin-film transistor including a source electrode and a drain electrode, wherein the first electrode of the light-emitting device may be electrically connected to the source electrode or the drain electrode. In an embodiment, the electronic apparatus may further include a color filter, a color conversion layer, a touch screen layer, a polarizing layer, or one or more combinations thereof. More details on the electronic apparatus may each independently be the same as described in the present disclosure.
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
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. In an embodiment, 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 one or more combinations thereof. In one or more 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-ln), magnesium-silver (Mg—Ag), or one or more combinations thereof.
The first electrode 110 may have a single-layered structure including (e.g., consisting of) a single layer or a multi-layered structure including a plurality of layers. For example, the first electrode 110 may have a three-layered structure of ITO/Ag/ITO.
The interlayer 130 may be arranged on the first electrode 110. The interlayer 130 may include an emission layer. The emission layer may include the first emission layer and the second emission layer.
The interlayer 130 may further include a hole transport region arranged between the first electrode 110 and the emission layer and an electron transport region arranged between the emission layer and the second electrode 150.
The interlayer 130 may further include, in addition to one or more suitable organic materials, a metal-containing compound such as an organometallic compound, an inorganic material such as a quantum dot, and/or the like.
In an embodiment, the interlayer 130 may include, i) two or more emitting units sequentially stacked between the first electrode 110 and the second electrode 150, and ii) a charge generation layer arranged among the two or more emitting units. When the interlayer 130 includes the two or more emitting units and the charge generation layer, the light-emitting device 10 may be a tandem light-emitting device.
The hole transport region may have: i) a single-layered structure including (e.g., consisting of) a single layer including (e.g., consisting of) a single material, ii) a single-layered structure including (e.g., consisting of) a single layer including (e.g., consisting of) a plurality of different materials, or iii) a multi-layered structure including a plurality of 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 one or more combinations 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, wherein the layers of each structure are stacked sequentially from the first electrode 110.
The hole transport region may further include a compound represented by Formula 201, a compound represented by Formula 202, or any combination thereof:
In Formulae 201 and 202,
For example, each of Formulae 201 and 202 may include at least one of groups represented by Formulae CY201 to CY217:
In Formulae CY201 to CY217, R10b and R10c may each be the same as described with respect to 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 above.
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 one or more embodiments, each of Formulae 201 and 202 may include at least one of the groups represented by Formulae CY201 to CY203.
In one or more 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 one or more 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 one or more embodiments, each of Formulae 201 and 202 may not include (e.g., may exclude) a group represented by one of Formulae CY201 to CY203.
In one or more embodiments, each of Formulae 201 and 202 may not include (e.g., may exclude) 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 one or more embodiments, each of Formulae 201 and 202 may not include (e.g., may exclude) a group represented by one of Formulae CY201 to CY217.
For example, the hole transport region may include at least one of Compounds HT1 to HT50, 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), CzSi(9-(4-tert-Butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole), or one or more combinations 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. 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, about 100 Å to about 1,000 Å, and a thickness of the hole transport layer may be in a range of about 50 Å to about 2,000 Å, for example, about 100 Å to about 1,500 Å. When the thicknesses of the hole transport region, the hole injection layer, and the hole transport layer are within these ranges, satisfactory (suitable) hole transporting characteristics may be obtained without a substantial increase in driving voltage.
The emission auxiliary layer may increase light-emission efficiency by compensating for an optical resonance distance according to the wavelength of light emitted by an emission layer, and the electron blocking layer may block or reduce the leakage of electrons from an emission layer to a hole transport region. Materials that may be included in the hole transport region may be included in the emission auxiliary layer and the electron blocking layer.
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 substantially uniformly or non-uniformly dispersed in the hole transport region (for example, in the form of a single layer including (e.g., 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 -3.5 eV or less.
In one or more embodiments, the p-dopant may include a quinone derivative, a cyano group-containing compound, a compound including element EL1 and element EL2, or one or more combinations thereof.
Examples of the quinone derivative are TCNQ, F4-TCNQ, and/or the like.
Examples of the cyano group-containing compound are HAT-CN, a compound represented by Formula 221, and/or the like:
In Formula 221,
In the compound including 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 are an alkali metal (for example, lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and/or the like); alkaline earth metal (for example, beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and/or the like); 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), and/or the like); post-transition metal (for example, zinc (Zn), indium (In), tin (Sn), and/or the like); and 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), and/or the like).
Examples of the metalloid are silicon (Si), antimony (Sb), tellurium (Te), and/or the like.
Examples of the non-metal are oxygen (O) and halogen (for example, F, Cl, Br, I, and/or the like).
Examples of the compound including element EL1 and element EL2 are metal oxide, metal halide (for example, metal fluoride, metal chloride, metal bromide, or metal iodide), metalloid halide (for example, metalloid fluoride, metalloid chloride, metalloid bromide, or metalloid iodide), metal telluride, or one or more combinations thereof.
Examples of the metal oxide are tungsten oxide (for example, WO, W2O3, WO2, WO3, W2O5, and/or the like), vanadium oxide (for example, VO, V2O3, VO2, V2O5, and/or the like), molybdenum oxide (MoO, Mo2O3, MoO2, MoO3, Mo2O5, and/or the like), rhenium oxide (for example, ReOs and/or the like), and/or the like.
Examples of the metal halide are alkali metal halide, alkaline earth metal halide, transition metal halide, post-transition metal halide, lanthanide metal halide, and/or the like.
Examples of the alkali metal halide are LiF, NaF, KF, RbF, CsF, LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI, RbI, CsI, and/or the like.
Examples of the alkaline earth metal halide are BeF2, MgF2, CaF2, SrF2, BaF2, BeCl2, MgCl2, CaCl2, SrCl2, BaCl2, BeBr2, MgBr2, CaBr2, SrBr2, BaBr2, BeI2, Mgl2, CaI2, SrI2, BaI2, and/or the like.
Examples of the transition metal halide are titanium halide (for example, TiF4, TiCl4, TiBr4, TiI4, and/or the like), zirconium halide (for example, ZrF4, ZrCl4, ZrBr4, Zrl4, and/or the like), hafnium halide (for example, HfF4, HfCl4, HfBr4, HfI4, and/or the like), vanadium halide (for example, VF3, VCl3, VBr3, Vl3, and/or the like), niobium halide (for example, NbF3, NbCls, NbBr3, NbI3, and/or the like), tantalum halide (for example, TaF3, TaCl3, TaBr3, TaI3, and/or the like), chromium halide (for example, CrF3, CrCl3, CrBr3, CrI3, and/or the like), molybdenum halide (for example, MoF3, MoCl3, MoBr3, MoI3, and/or the like), tungsten halide (for example, WF3, WCl3, WBr3, Wl3, and/or the like), manganese halide (for example, MnF2, MnCl2, MnBr2, MnI2, and/or the like), technetium halide (for example, TcF2, TcCl2, TcBr2, TcI2, and/or the like), rhenium halide (for example, ReF2, ReCl2, ReBr2, ReI2, and/or the like), ferroushalide (for example, FeF2, FeCl2, FeBr2, FeI2, and/or the like), ruthenium halide (for example, RuF2, RuCl2, RuBr2, RuI2, and/or the like), osmium halide (for example, OsF2, OsCl2, OsBr2, OsI2, and/or the like), cobalt halide (for example, CoF2, CoCl2, CoBr2, CoI2, and/or the like), rhodium halide (for example, RhF2, RhCl2, RhBr2, RhI2, and/or the like), iridium halide (for example, IrF2, IrCl2, IrBr2, IrI2, and/or the like), nickel halide (for example, NiF2, NiCl2, NiBr2, NiI2, and/or the like), palladium halide (for example, PdF2, PdCl2, PdBr2, PdI2, and/or the like), platinum halide (for example, PtF2, PtCl2, PtBr2, PtI2, and/or the like), cuproushalide (for example, CuF, CuCI, CuBr, CuI, and/or the like), silver halide (for example, AgF, AgCl, AgBr, AgI, and/or the like), gold halide (for example, AuF, AuCl, AuBr, AuI, and/or the like), and/or the like.
Examples of the post-transition metal halide are zinc halide (for example, ZnF2, ZnCl2, ZnBr2, ZnI2, and/or the like), indium halide (for example, InI3 and/or the like), tin halide (for example, SnI2 and/or the like), and/or the like.
Examples of the lanthanide metal halide are YbF, YbF2, YbF3, SmF3, YbCl, YbCl2, YbCl3 SmCl3, YbBr, YbBr2, YbBr3 SmBr3, YbI, YbI2, YbI3, SmI3, and/or the like.
An example of the metalloid halide is antimony halide (for example, SbCl5 and/or the like).
Examples of the metal telluride are alkali metal telluride (for example, Li2Te, Na2Te, K2Te, Rb2Te, Cs2Te, and/or the like), alkaline earth metal telluride (for example, BeTe, MgTe, CaTe, SrTe, BaTe, and/or the like), 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, and/or the like), post-transition metal telluride (for example, ZnTe and/or the like), and lanthanide metal telluride (for example, LaTe, CeTe, PrTe, NdTe, PmTe, EuTe, GdTe, TbTe, DyTe, HoTe, ErTe, TmTe, YbTe, LuTe, and/or the like).
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 an embodiment, 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 one or more 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 are mixed with each other in a single layer to emit white light. For example, the emission layer may emit blue light.
For example, the blue light may have a wavelength in a range of about 400 nm to about 490 nm. For example, the blue light may have a wavelength in a range of about 440 nm to about 470 nm.
In an embodiment, the emission layer may include the first emission layer and the second emission layer, the first emission layer may include the first host, and the second emission layer may include the second host. The first host may include the first-first host and the first-second host, and the second host may include the second-first host and the second-second host.
The dopant may include the compound represented by Formula 3.
The phosphorescent dopant or the fluorescent dopant that may be included in the emission layer may be understood by referring to the descriptions of the phosphorescent dopant or the fluorescent dopant provided herein.
In one or more embodiments, the emission layer may include a quantum dot.
In one or more 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. When the thickness of the emission layer is within these ranges, excellent or suitable luminescence characteristics may be obtained without a substantial increase in driving voltage.
In an embodiment, the first host and the second host may each independently further include a carbazole-containing compound, an anthracene-containing compound, a triazine-containing compound, or one or more combinations thereof. In one or more embodiments, the first host and the second may each independently further include, for example, a carbazole-containing compound and/or a triazine-containing compound.
In one or more embodiments, the first host and the second host may each independently further include a compound represented by Formula 301:
[00219] wherein, in Formula 301,
For example, when xb11 in Formula 301 is 2 or more, two or more of Ar301 may be linked to each other via a single bond.
In one or more embodiments, the first host and the second host may each independently further include a compound represented by Formula 301-1, a compound represented by Formula 301-2, or any combination thereof:
In Formulae 301-1 and 301-2,
In one or more embodiments, the first host and the second host may each independently further include an alkaline earth metal complex, a post-transition metal complex, or any combination thereof. For example, the first host and the second host may each independently further include a Be complex (for example, Compound H55), a Mg complex, a Zn complex, or one or more combinations thereof.
In one or more embodiments, the first host and the second host may each independently further include at least one of Compounds H1 to H131, 9,10-di(2-naphthyl)anthracene (DNA), 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-carbazolyl)benzene (mCP), 1,3,5-tri(carbazol-9-yl)benzene (TCP), or one or more combinations thereof:
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 one or more combinations 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,
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 an embodiment, when xc1 in Formula 401 is 2 or more, two ring A401(s) among two or more of L401(s) may be optionally linked to each other via T402, which is a linking group, and two ring A402(s) among two or more of L401(s) may be optionally linked to each other via T403, which is a linking group (see Compounds PD1 to PD4 and PD7). T402 and T403 may respectively be the same as described in connection with T401.
In Formula 401, L402 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) group, an isonitrile group, a —CN group, a phosphorus containing group (for example, a phosphine group, a phosphite group, and/or the like), or one or more combinations thereof.
The phosphorescent dopant may include, for example, at least one Compounds PD1 to PD39, PS-1, PS-2, or one or more combinations thereof:
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:
In Formula 501,
For example, Ar501 in Formula 501 may be a condensed cyclic group (for example, an anthracene group, a chrysene group, or a pyrene group) in which three or more monocyclic groups are condensed together.
In an embodiment, xd4 in Formula 501 may be 2.
For example, the fluorescent dopant may include: at least one of Compounds FD1 to FD36; DPVBi; DPAVBi; or one or more combinations thereof:
The emission layer may further include a delayed fluorescence material. The second emission layer may further include a delayed fluorescence material.
In the present specification, the delayed fluorescence material may be selected from compounds capable of emitting delayed fluorescent light based on a delayed fluorescence emission mechanism.
The delayed fluorescence material, which is further included in the emission layer, may act as a host or a dopant depending on the type or kind of other materials included in the emission layer. The delayed fluorescence material further included in the second emission layer may act as a host or a dopant, depending on the type or kind of other materials included in the second emission layer.
In an embodiment, a difference between a triplet energy level (eV) of the delayed fluorescence material and a singlet energy level (eV) of the delayed fluorescence material may be greater than or equal to 0 eV and less than or equal to 0.5 eV. When the difference between the triplet energy level (eV) of the delayed fluorescence material and the singlet energy level (eV) of the delayed fluorescence material is satisfied within the range above, up-conversion from the triplet state to the singlet state of the delayed fluorescence materials may effectively occur, thereby improving (increasing) luminescence efficiency of the light-emitting device 10.
For example, the 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 atom (B).
The delayed fluorescence material may include, for example, at least one of Compounds DF1 to DF9:
The emission layer may include a quantum dot. The second emission layer may include a quantum dot.
The term “quantum dot” as utilized herein refers to a crystal of a semiconductor compound, and may include any suitable material capable of emitting light of one or more suitable emission wavelengths according to the size of the crystal.
A diameter of the quantum dot (e.g., an average diameter of quantum dots) may be, for example, in a range of about 1 nm to about 10 nm.
The quantum dot may be synthesized by a wet chemical process, a metal organic chemical vapor deposition (MOCVD) process, a molecular beam epitaxy (MBE) process, or any process similar thereto.
The wet chemical process is a method including mixing a precursor material with an organic solvent and then growing a quantum dot particle crystal. When the crystal grows, the organic solvent naturally acts as a dispersant coordinated on the surface of the quantum dot crystal and controls the growth of the crystal so that the growth of quantum dot particles can be controlled or selected through a process which costs less, and is easier than vapor deposition methods, such as metal organic chemical vapor deposition process or molecular beam epitaxy process.
The quantum dot may include a Group II-VI semiconductor compound, a Group III-V semiconductor compound, a Group III-VI semiconductor compound, a Group I-III-VI semiconductor compound, a Group IV-VI semiconductor compound, a Group IV element or compound, or one or more combinations thereof.
Examples of the Group II-VI semiconductor compound are: a binary compound, such as CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, or MgS; a ternary compound, such as CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, or MgZnS; a quaternary compound, such as CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, or HgZnSTe; and/or one or more combinations thereof.
Examples of the Group III-V semiconductor compound are: a binary compound such as GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, or InSb; a ternary compound such as GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InNP, InAlP, InNAs, InNSb, InPAs, or InPSb; a quaternary compound such as GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, or InAlPSb; and/or one or more combinations thereof. In some embodiments, the Group III-V semiconductor compound may further include a Group II element. Examples of the Group III-V semiconductor compound further including a Group II element are InZnP, InGaZnP, InAIZnP, and/or the like
Examples of the Group III-VI semiconductor compound are: a binary compound, such as GaS, GaSe, Ga2Se3, GaTe, InS, InSe, In2S3, In2Se3, or InTe; a ternary compound, such as InGaS3, or InGaSe3; and/or one or more combinations thereof.
Examples of the Group I-III-VI semiconductor compound are: a ternary compound, such as AgInS, AgInS2, CuInS, CuInS2, CuGaO2, AgGaO2, or AgAlO2; and/or one or more combinations thereof.
Examples of the Group IV-VI semiconductor compound are: a binary compound, such as SnS, SnSe, SnTe, PbS, PbSe, or PbTe; a ternary compound, such as SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, or SnPbTe; a quaternary compound, such as SnPbSSe, SnPbSeTe, or SnPbSTe; and/or one or more combinations thereof.
The Group IV element or compound are: a single element compound, such as Si or Ge; a binary compound, such as SiC or SiGe; or one or more combinations thereof.
Each element included in a multi-element compound such as the binary compound, the ternary compound, and/or the quaternary compound may be present at a substantially uniform concentration or non-uniform concentration in a particle.
In some embodiments, the quantum dot may have a single structure in which the concentration of each element in the quantum dot is substantially uniform, or a core-shell dual structure. For example, the material included in the core and the material included in the shell may be different from each other.
The shell of the quantum dot may act as a protective layer that prevents chemical degeneration of the core to maintain semiconductor characteristics, and/or as a charging layer that imparts electrophoretic characteristics to the quantum dot. The shell may be a single layer or a multi-layer. The interface between the core and the shell may have a concentration gradient in which the concentration of an element existing in the shell decreases toward the center of the core.
Examples of the shell of the quantum dot may be an oxide of metal, metalloid, or non-metal, a semiconductor compound, and/or one or more combinations thereof. Examples of the oxide of metal, metalloid, or non-metal are a binary compound, such as SiO2, Al2O3, TiO2, ZnO, MnO, Mn2O3, Mn3O4, CuO, FeO, Fe2O3, Fe3O4, CoO, Co3O4, or NiO; a ternary compound, such as MgAl2O4, CoFe2O4, NiFe2O4, or CoMn2O4; and/or one or more combinations thereof. Examples of the semiconductor compound are, as described herein, a Group II-VI semiconductor compound; a Group III-V semiconductor compound; a Group III-VI semiconductor compound; a Group I-III-VI semiconductor compound; a Group IV-VI semiconductor compound; and/or one or more combinations thereof. For example, the semiconductor compound may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AIP, AlSb, or one or more combinations thereof.
A full width at half maximum (FWHM) of the emission wavelength spectrum of the quantum dot may be about 45 nm or less, for example, about 40 nm or less, for example, about 30 nm or less, and within these ranges, color purity or color reproducibility may be increased. In some embodiments, because the light emitted through the quantum dot is emitted in all directions, the wide viewing angle may be improved (increased).
In some embodiments, the quantum dot may be in the form of a substantially spherical particle, a pyramidal particle, a multi-arm particle, a cubic nanoparticle, a nanotube particle, a nanowire particle, a nanofiber particle, or a nanoplate particle.
Because the energy band gap may be adjusted by controlling (selecting) the size of the quantum dot, light having one or more suitable wavelength bands may be obtained from the quantum dot emission layer. Accordingly, by utilizing quantum dots of different sizes, a light-emitting device that emits light of one or more suitable wavelengths may be implemented. In some embodiments, the size of the quantum dot may be selected to emit red, green, and/or blue light. In some embodiments, the size of the quantum dots may be configured to emit white light by a combination of light of one or more suitable colors.
The electron transport region may have: i) a single-layered structure including (e.g., consisting of) a single layer including (e.g., consisting of) a single material, ii) a single-layered structure including (e.g., consisting of) a single layer including (e.g., consisting of) a plurality of different materials, or iii) a multi-layered structure including a plurality of layers including different materials.
The electron transport region may include a buffer layer, a hole blocking layer, an electron transport layer, an electron control layer, an electron injection layer, or one or more combinations 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, an electron control layer/electron transport layer/electron injection layer structure, or a buffer layer/electron transport layer/electron injection layer structure, wherein the layers of each structure are stacked sequentially from the emission layer.
The electron transport region (for example, the buffer layer, the hole blocking layer, the electron control layer, or the electron transport layer in the electron transport region) may further 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 further include a compound represented by Formula 601:
[00298] wherein, in Formula 601,
For example, when xe11 in Formula 601 is 2 or more, two or more of Ar601 may be linked to each other via a single bond.
In an embodiment, Ar601 in Formula 601 may be a substituted or unsubstituted anthracene group.
In one or more embodiments, the electron transport region may further include a compound represented by Formula 601-1 :
[00309] wherein, in Formula 601-1,
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 at least 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, TSPO1, TPBI, DBFTRZ, or one or more combinations thereof:
A thickness of the electron transport region may be from about 100 Å to about 5,000 Å, for example, about 160 Å to about 4,000 Å. When the electron transport region includes a buffer layer, a hole blocking layer, an electron control layer, an electron transport layer, or one or more combinations thereof, a thickness of the buffer layer, the hole blocking layer, or the electron control layer may 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. When the thickness of the buffer layer, the hole blocking layer, the electron control layer, the electron transport layer, and/or the electron transport layer are within these ranges, satisfactory (suitable) 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. 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 one or more combinations 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 directly contact the second electrode 150.
The electron injection layer may have: i) a single-layered structure including (e.g., consisting of) a single layer including (e.g., consisting of) a single material, ii) a single-layered structure including (e.g., consisting of) a single layer including (e.g., consisting of) a plurality of different materials, or iii) a multi-layered structure including a plurality of layers including different materials.
The electron injection layer may include an alkali metal, alkaline earth metal, a rare earth metal, an alkali metal-containing compound, 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 one or more combinations thereof.
The alkali metal may include Li, Na, K, Rb, Cs, or one or more combinations thereof. The alkaline earth metal may include Mg, Ca, Sr, Ba, or one or more combinations thereof. The rare earth metal may include Sc, Y, Ce, Tb, Yb, Gd, or one or more combinations 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 one or more combinations 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, Lil, Nal, Csl, or KI; or one or more combinations thereof. The alkaline earth metal-containing compound may include an alkaline earth metal oxide, such as BaO, SrO, CaO, BaxSr1-xO (wherein 0<x<1), BaxCa1-xO (wherein 0<x<1), and/or the like. The rare earth metal-containing compound may include YbF3, ScF3, Sc2O3, Y2O3, Ce2O3, GdF3, TbF3, Ybl3, Scl3, Tbl3, or one or more combinations thereof. In an embodiment, the rare earth metal-containing compound may include lanthanide metal telluride. Examples of the lanthanide metal telluride are 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, Lu2Te3, and/or the like.
The alkali metal complex, the alkaline earth-metal complex, and the rare earth metal complex may include i) one of metal ions of the alkali metal, the alkaline earth metal, and the rare earth metal and ii) 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 one or more combinations thereof.
In an embodiment, the electron injection layer may include (e.g., 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 one or more combinations thereof, as described above. In one or more embodiments, the electron injection layer may further include an organic material (for example, a compound represented by Formula 601).
In one or more embodiments, the electron injection layer may include (e.g., consist of): i) an alkali metal-containing compound (for example, an alkali metal halide); or ii) a) an alkali metal-containing compound (for example, an alkali metal halide), and b) an alkali metal, an alkaline earth metal, a rare earth metal, or one or more combinations thereof. For example, the electron injection layer may be a KI:Yb co-deposited layer, an Rbl:Yb co-deposited layer, and/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 one or more combinations thereof may be substantially 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, and, for example, about 3 Å to about 90 Å. When the thickness of the electron injection layer is within the ranges above, satisfactory (suitable) electron injection characteristics may be obtained without a substantial increase in driving voltage.
The second electrode 150 may be arranged on the interlayer 130 having a structure 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 one or more combinations thereof, each having a low-work function, may be utilized.
The second electrode 150 may include Li, Ag, Mg, Al, Al—Li, Ca, Mg—In, Mg—Ag, Yb, Ag—Yb, ITO, IZO, or one or more combinations 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 a plurality of layers.
A first capping layer may be located outside the first electrode 110, and/or a second capping layer may be located outside the second electrode 150. In particular, 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 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 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 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 is 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 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 emission efficiency according to the principle of constructive interference. Accordingly, the light extraction efficiency of the light-emitting device 10 is increased, so that the luminescence efficiency of the light-emitting device 10 may be improved (increased).
Each of the first capping layer and the second capping layer may include a material having a refractive index of 1.6 or more (at the wavelength of 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, porphyrin derivatives, phthalocyanine derivatives, naphthalocyanine derivatives, alkali metal complexes, alkaline earth metal complexes, or one or more combinations 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 one or more combinations thereof. In one or more embodiments, at least one selected from the first capping layer and the second capping layer may each independently include an amine group-containing compound.
For example, at least one selected from 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 an embodiment, at least one selected from the first capping layer and the second capping layer may each independently include at least one of Compounds HT28 to HT33, at least one of Compounds CP1 to CP6, β-NPB, P4, or one or more combinations thereof:
The light-emitting device may be included in one or more suitable electronic apparatuses. For example, the electronic apparatus including the light-emitting device may be a light-emitting apparatus, an authentication apparatus, and/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 or white light. For details on the light-emitting device, related description provided above may be referred to. In one or more embodiments, the color conversion layer may include a quantum dot. The quantum dot may be, for example, a quantum dot as described herein.
The electronic apparatus may include a first substrate. The first substrate may include a plurality of subpixel areas, the color filter may include a plurality of color filter areas respectively corresponding to the subpixel areas, and the color conversion layer may include a plurality of color conversion areas respectively corresponding to the subpixel areas.
A pixel-defining film may be located among the subpixel areas to define each of the subpixel areas.
The color filter may further include a plurality of color filter areas and light-shielding patterns located among the color filter areas, and the color conversion layer may further include a plurality of color conversion areas and light-shielding patterns located among the color conversion areas.
The plurality of color filter areas (or the plurality of 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 plurality of color filter areas (or the plurality of color conversion areas) may include quantum dots. In particular, 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 (e.g., may exclude) a quantum dot. For more details on the quantum dot, related descriptions provided herein may be referred to. 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. 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 particular, 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 either the source electrode or the drain electrode may be electrically connected to either the first electrode or the second electrode of the light-emitting device.
The thin-film transistor may further include a gate electrode, a gate insulating film, and/or the like.
The activation layer may include crystalline silicon, amorphous silicon, an organic semiconductor, an oxide semiconductor, and/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 conversion layer and/or color filter and the light-emitting device. The sealing portion allows light from the light-emitting device to be extracted to the outside, and concurrently (e.g., simultaneously) prevents (reduces) ambient air and moisture from penetrating into the light-emitting device. The sealing portion may be a sealing substrate including a transparent glass substrate and/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 suitable functional layers may be additionally located 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/or 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 utilizing biometric information of a living body (for example, fingertips, pupils, and/or the like).
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 one or more suitable 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, one or more suitable measuring instruments, meters (for example, meters for a vehicle, an aircraft, and a vessel), projectors, and/or the like.
The light-emitting apparatus of
The substrate 100 may be a flexible substrate, a glass substrate, and/or a metal substrate. A buffer layer 210 may be located on the substrate 100. The buffer layer 210 may prevent or reduce 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 and between the gate electrode 240 and the drain electrode 270, to insulate the gate electrode from the source electrode and to insulate the gate electrode from the drain electrode.
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 located in contact with the exposed portions of the source region and the drain region of the activation layer 220.
The TFT 200 is electrically connected to a light-emitting device to drive the light-emitting device, and is 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 is 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 located to be 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. At least some layers of the interlayer 130 may extend beyond the upper portion of the pixel defining layer 290 to be located in the form of a common layer.
The second electrode 150 may be located 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 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 (e.g., reduce the amount of moisture and/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 one or more combinations thereof; an organic film including polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, polyethylene sulfonate, polyoxymethylene, polyarylate, hexamethyldisiloxane, an acrylic-based resin (for example, polymethyl methacrylate, polyacrylic acid, and/or the like), an epoxy-based resin (for example, aliphatic glycidyl ether (AGE), and/or the like), or one or more combinations thereof; or any combination of the inorganic films and the organic films.
The electronicapparatus 190 of
The layers included in the hole transport region, the emission layer, and the layers included in the electron transport region may be formed in a certain region by utilizing one or more suitable methods such as vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) deposition, ink-jet printing, laser-printing, laser-induced thermal imaging, and/or the like.
When layers including the hole transport region, an emission layer, and layers including 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 a deposition speed 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.
The term “C3-C60 carbocyclic group” as utilized herein refers to a cyclic group consisting of carbon only as a ring-forming atom and having three to sixty carbon atoms, and the term “C1-C60 heterocyclic group” as utilized herein refers to 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 has 3 to 61 ring-forming atoms.
The term “cyclic group” as utilized herein may include the C3-C60 carbocyclic group, and the C1-C60 heterocyclic group.
The term “π electron-rich C3-C60 cyclic group” as utilized herein refers to a cyclic group that has three to sixty carbon atoms and does not include *—N═*’ as a ring-forming moiety, and the term “π electron-deficient nitrogen-containing C1-C60 cyclic group” as utilized herein refers to a heterocyclic group that has one to sixty carbon atoms and includes *—N═*’ as a ring-forming moiety.
For example,
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 utilized herein refer to 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, and/or the like) according to the structure of a formula for which the corresponding term is utilized. For example, the “benzene group” may be a benzo group, a phenyl group, a phenylene group, and/or the like, which may be easily 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 are 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/or a monovalent non-aromatic condensed heteropolycyclic group. Examples of the divalent C3-C60 carbocyclic group and the divalent C1-C60 heterocyclic group are 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/or a divalent non-aromatic condensed heteropolycyclic group.
The term “C1-C60 alkyl group” as utilized herein refers to a linear or branched aliphatic hydrocarbon monovalent group that has one to sixty carbon atoms, and specific examples thereof are 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 utilized herein refers to a divalent group having the same structure as the C1-C60 alkyl group.
The term “C2-C60 alkenyl group” as utilized herein refers to 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 are an ethenyl group, a propenyl group, and a butenyl group. The term “C2-C60 alkenylene group” as utilized herein refers to a divalent group having the same structure as the C2-C60 alkenyl group.
The term “C2-C60 alkynyl group” as utilized herein refers to 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 include an ethynyl group and a propynyl group. The term “C2-C60 alkynylene group” as utilized herein refers to a divalent group having the same structure as the C2-C60 alkynyl group.
The term “C1-C60 alkoxy group” as utilized herein refers to a monovalent group represented by -OA101 (wherein A101 is 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 utilized herein refers to a monovalent saturated hydrocarbon cyclic group having 3 to 10 carbon atoms, and examples thereof are a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, 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 utilized herein refers to a divalent group having the same structure as the C3-C10 cycloalkyl group.
The term “C1-C10 heterocycloalkyl group” as utilized herein refers to 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 specific examples are a 1,2,3,4-oxatriazolidinyl group, a tetrahydrofuranyl group, and a tetrahydro thiophenyl group. The term “C1-C10 heterocycloalkylene group” as utilized herein refers to a divalent group having the same structure as the C1-C10 heterocycloalkyl group.
The term C3-C10 cycloalkenyl group utilized herein refers to 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 specific examples thereof are a cyclopentenyl group, a cyclohexenyl group, and a cycloheptenyl group. The term “C3-C10 cycloalkenylene group” as utilized herein refers to a divalent group having the same structure as the C3-C10 cycloalkenyl group.
The term “C1-C10 heterocycloalkenyl group” as utilized herein refers to 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/or a 2,3-dihydrothiophenyl group. The term “C1-C10 heterocycloalkenylene group” as utilized herein refers to a divalent group having the same structure as the C1-C10 heterocycloalkenyl group.
The term “C6-C60 aryl group” as utilized herein refers to a monovalent group having a carbocyclic aromatic system of 6 to 60 carbon atoms, and the term “C6-C60 arylene group” as utilized herein refers to a divalent group having a carbocyclic aromatic system of 6 to 60 carbon atoms. Examples of the C6-C60 aryl group are 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, an ovalenyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, and/or the like. When the C6-C60 aryl group and the C6-C60 arylene group each include two or more rings, the rings may be condensed with each other.
The term “C1-C60 heteroaryl group” as utilized herein refers to 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 utilized herein refers to 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 are 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, a naphthyridinyl group, an azafluorenyl group, a carbazolyl group, an azacarbazolyl group, an indeno carbazolyl group, an indolocarbazolyl group, a benzofurocarbazolyl group, a benzothienocarbazolyl group, a benzosilolocarbazolyl group, a benzoindolocarbazolyl group, a benzocarbazolyl group, and/or the like. When the C1-C60 heteroaryl group and the C1-C60 heteroarylene group each include two or more rings, the rings may be condensed with each other.
The term “monovalent non-aromatic condensed polycyclic group” as utilized herein refers to a monovalent group (for example, having 8 to 60 carbon atoms) having two or more rings condensed to each other, only carbon atoms as ring-forming atoms, and no aromaticity in its entire molecular structure. Examples of the monovalent non-aromatic condensed polycyclic group are an indenyl group, an indenophenanthrenyl group, and/or an indeno anthracenyl group. The term “divalent non-aromatic condensed polycyclic group” as utilized herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed polycyclic group described above.
The term “monovalent non-aromatic condensed heteropolycyclic group” as utilized herein refers to 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 nonaromaticity in its entire molecular structure. Examples of the monovalent non-aromatic condensed heteropolycyclic group 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 dibenzosilolyl group, a dibenzothiophenyl group, a dibenzofuranyl 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, 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 utilized herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed heteropolycyclic group described above.
The term “C6-C60 aryloxy group” as utilized herein indicates -OA102 (wherein A102 is a C6-C60 aryl group), and the term “C6-C60 arylthio group” as utilized herein indicates -SA103 (wherein A103 is a C6-C60 aryl group).
The term “C7-C60 arylalkyl group” as utilized herein refers to -A104A105 (where A104 may be a C1-C54 alkylene group, and A105 may be a C6-C59 aryl group), and the term C2-C60 heteroarylalkyl group” as utilized herein refers to -A106A107 (where A106 may be a C1-C59 alkylene group, and A107 may be a C1-C59 heteroaryl group).
The term “R10a” as utilized herein refers to:
Q1 to Q3, Q11 to Q13, Q21 to Q23 and Q31 to Q33 utilized 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; a C3-C60 carbocyclic group or a C1-C60 heterocyclic group, each unsubstituted or substituted with deuterium, -F, a cyano group, a C1-C60 alkyl group, a C1-C60 alkoxy group, a phenyl group, a biphenyl group, or one or more combinations thereof; a C7-C60 arylalkyl group; or a C2-C60 heteroarylalkyl group.
The term “heteroatom” as utilized herein refers to any atom other than a carbon atom. Examples of the heteroatom are O, S, N, P, Si, B, Ge, Se, and/or one or more combinations thereof.
The term “third-row transition metal” as utilized herein includes hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), and/or the like.
“Ph” as utilized herein refers to a phenyl group, “Me” as utilized herein refers to a methyl group, “Et” as utilized herein refers to an ethyl group, “ter-Bu” or “But” as utilized herein refers to a tert-butyl group, and “OMe” as utilized herein refers to a methoxy group.
The term “biphenyl group” as utilized herein refers to “a phenyl group substituted with a phenyl group.” In other words, the “biphenyl group” is a substituted phenyl group having a C6-C60 aryl group as a substituent.
The term “terphenyl group” as utilized herein refers to “a phenyl group substituted with a biphenyl group”. In other words, the “terphenyl group” is a substituted phenyl group having, as a substituent, a C6-C60 aryl group substituted with a C6-C60 aryl group.
*, *’, *” and *’” as utilized herein, unless defined otherwise, each refer to a binding site to a neighboring atom in a corresponding formula or moiety.
Hereinafter, compounds according to embodiments and light-emitting devices according to embodiments will be described in more detail with reference to the following synthesis examples and examples. The wording “B was utilized instead of A” as utilized in describing Synthesis Examples refers to that an identical molar equivalent of B was utilized in place of A.
As an anode, a glass substrate on which 15 Ω/cm2 (1,200 Å) ITO electrode (available from Corning Co., Ltd) was formed was cut to a size of 50 mm×50 mm×0.7 mm, sonicated in isopropyl alcohol and pure water for 10 minutes in each solvent (i.e., in isopropyl alcohol for 10 minutes and pure water for 10 minutes), and cleaned by exposure to ultraviolet rays and ozone for 10 minutes. Then, the resultant substrate was mounted on a vacuum deposition apparatus.
m-MTDATA was deposited on the anode to form a hole injection layer having a thickness of about 40 Å, and NPB was deposited on the hole injection layer to form a hole transport layer having a thickness of about 100 Å.
Compound 1-1 (as a first-first host) and Compound 2-1 (as a first-second host) were co-deposited at a weight ratio of 1:1 on the hole transport layer to form a first emission layer having a thickness of 50 Å. On the first emission layer, Compound 1-1 (as a second-first host) and Compound 2-2 (as a second-second host) at a weight ratio of 1:1 and Compound 3-1 (as a dopant) at a ratio of 10 wt % with respect to the total weight of the second-first host and the second-second host were concurrently (e.g., simultaneously) co-deposited to form a second emission layer having a thickness of 400 Å.
Subsequently, DBFTRZ was deposited on the second emission layer to form a buffer layer having a thickness of 50 Å, ET1 was deposited on the buffer layer to form an electron transport layer having a thickness of 300 Å, and Mg was deposited on the electron transport layer to form a cathode having a thickness of 800 Å, thereby completing the manufacture of an organic light-emitting device.
Organic light-emitting devices were manufactured in substantially the same manner as in Example 1, except that compounds shown in Table 1 were utilized to form the first emission layer and the second emission layer. However, in ReferenceExamples 1 to 6, the emission layer was formed in a single-layered structure rather than a multi-layered structure.
Regarding each of the organic light-emitting devices of Examples 1 to 6 and Comparative Examples 1 to 12, external quantum efficiency (EQE) at 1,000 cd/m2 and lifespan (T95) were measured utilizing Keithley MU 236 and a luminance meter PR650.
In some embodiments, regarding each emission layer of the organic light-emitting devices of Examples 1, 2-1, 2-2, 3, 4-1 and 4-2, Comparative Examples 1, 3, 5-1, 5-2, 6-1 and 6-2, and Reference Example 1 to 6, a low-temperature (4 K) emission spectrum and a room temperature (300 K) emission spectrum were respectively measured utilizing a spectrophotometer. Then, in comparison with the room temperature emission spectrum, the starting point of the shortest wavelength of the spectrum observed only from the low-temperature emission spectrum was analyzed to evaluate triplet energy levels (T1). These values are shown in Table 1.
Referring to Table 1, it was confirmed that the organic light-emitting devices of Examples 1, 2-1, 2-2, 3, 4-1 and 4-2 having a multi-layered structure of the first emission layer and the second emission layer and satisfied a specific triplet energy condition between the first emission layer and the second emission layer each showed long lifespan and improved external quantum efficiency, compared to the organic light-emitting devices of Reference Examples 1 to 4 including the emission layer in a single layer and Comparative Example 1 and 3 including a multi-layered structure of the first emission layer and the second emission layer, and not satisfying the specific triplet energy condition between the first emission layer and the second emission layer..
In some embodiments, it was confirmed that the organic light-emitting devices of Comparative Example 5-1 to 5-2, and 6-1 to 6-2 including a multi-layered structure of the first emission layer and the second emission layer, and not satisfying a specific triplet energy condition between the first emission layer and the second emission layer showed a short lifespan and deteriorated (decreased) external quantum efficiency, compared to the organic light-emitting devices of Reference Examples 5 and 6 including the emission layer in a single layer and including same host and dopant in second emission layer.
According to the one or more embodiments, in a light-emitting device, a first emission layer may include a first host including a first-first host and a first-second host, but may not include (e.g., may exclude) a dopant; and a second emission layer may include a second host and a dopant, the second host including a second-first host and a second-second host. The first-first host and the first-second host may be different from each other, and the second-first host and the second-second host may be different from each other. A triplet energy level of the first host (TH1) may be greater than a triplet energy level of the second host (TH2), and thus the migration of triplet excitons formed in the first emission layer to the second emission layer may be promoted, whereas the migration of triplet excitons formed in the second emission layer to the first emission layer may be inhibited, thereby having excellent or suitable efficiency and long lifespan. In this regard, an electronic apparatus having high efficiency and long lifespan may be prepared.
The use of “may” when describing embodiments of the present disclosure refers to “one or more embodiments of the present disclosure.”
As used herein, the term “substantially,” “about,” and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent deviations in measured or calculated values that would be recognized by those of ordinary skill in the art. “About” or “approximately,” as used herein, is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with measurement of the particular quantity (i.e., the limitations of the measurement system). For example, “about” may mean within one or more standard deviations, or within ± 30%, ± 20%, ± 10%, or ± 5% of the stated value.
Also, any numerical range recited herein is intended to include all subranges of the same numerical precision subsumed within the recited range. For example, a range of “1.0 to 10.0” is intended to include all subranges between (and including) the recited minimum value of 1.0 and the recited maximum value of 10.0, that is, having a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as, for example, 2.4 to 7.6. Any maximum numerical limitation recited herein is intended to include all lower numerical limitations subsumed therein and any minimum numerical limitation recited in this disclosure is intended to include all higher numerical limitations subsumed therein. Accordingly, Applicant reserves the right to amend this disclosure, including the claims, to expressly recite any sub-range subsumed within the ranges expressly recited herein.
The electronic apparatus or any other relevant devices or components according to embodiments of the present disclosure described herein may be implemented utilizing any suitable hardware, firmware (e.g., an application-specific integrated circuit), software, or a combination of software, firmware, and hardware. For example, the various components of the apparatus may be formed on one integrated circuit (IC) chip or on separate IC chips. Further, the various components of the apparatus may be implemented on a flexible printed circuit film, a tape carrier package (TCP) or a printed circuit board (PCB), or formed on one substrate. Further, the various components of the apparatus may be a process or thread, running on one or more processors, in one or more computing devices, executing computer program instructions and interacting with other system components for performing the various functionalities described herein. The computer program instructions are stored in a memory which may be implemented in a computing device using a standard memory device, such as, for example, a random access memory (RAM). The computer program instructions may also be stored in other non-transitory computer readable media such as, for example, a CD-ROM, flash drive, or the like. Also, a person of skill in the art should recognize that the functionality of various computing devices may be combined or integrated into a single computing device, or the functionality of a particular computing device may be distributed across one or more other computing devices without departing from the scope of the embodiments of the present disclosure.
It should be understood that embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments. While one or more embodiments have been described with reference to the drawings, it will be understood by those of ordinary skill in the art that one or more suitable changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined by the following claims and equivalents thereof.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2021-0186588 | Dec 2021 | KR | national |
