Patent Application
20250204246
The present application claims priority to and the benefit of Korean Patent Application No. 10-2023-0185077, filed on Dec. 18, 2023, in the Korean Intellectual Property Office, the entire content of which is hereby incorporated by reference.
One or more embodiments of the present disclosure relate to an organic light-emitting device and an electronic apparatus including the same.
Organic light-emitting devices are self-emissive devices that, as compared with other devices of the related art, have wide viewing angles, high contrast ratios, short response times, and excellent characteristics in terms of luminance, driving voltage, and response speed.
In an example, an organic light-emitting device may have a structure in which 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 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. The excitons transition from an excited state to a ground state, thereby generating light.
One or more embodiments of the present disclosure include a light-emitting device having improved lifespan and an electronic apparatus including the same.
Additional aspects of embodiments will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments of the disclosure.
According to one or more embodiments, a light-emitting device includes:
In Conditions 1) to 3),
According to one or more embodiments,
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 the specification. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described below, by referring to the figures, to explain aspects of embodiments of the present description. As used 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 or c” indicates only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof.
The term “exciplex host” as used herein refers to a host consisting of a combination of hosts that form an exciplex in an emission layer, or an exciplex formed by the combination of hosts.
An exciplex refers to a complex in a short-lived excited state formed between two molecules (for example, an electron donor and an electron acceptor).
The term “high temperature” as used herein refers to temperatures greater than room temperature and may be a temperature of about 40° C. to 60° C.
The expression “as a temperature of the emission layer increases, the value of knrs is constant” as used herein may mean that the range of variance of the value of knrs is within about 2% based on the lower value of knrs.
A light-emitting device according to one or more embodiments includes:
The first host may be a hole-transporting host, and the second host may be an electron-transporting host.
A difference between the highest occupied molecular orbital (HOMO) energy of the first host and the HOMO energy of the second host and a difference between the lowest unoccupied molecular orbital (LUMO) energy of the first host and the LUMO energy of the second host may each be greater than or equal to 0.2 eV.
For example, a difference between the HOMO energy of the first host and the HOMO energy of the second host may be greater than 0.2 eV and may be less than or equal to the band gap of the second host.
For example, a difference between the LUMO energy of the first host and the LUMO energy of the second host may be greater than 0.2 eV and may be less than or equal to the band gap of the second host.
An exciplex may be formed by having such a difference in HOMO and LUMO energy between the first host and the second host. In an embodiment, photoluminescence of the exciplex host may exhibit both prompt fluorescence (e.g., non-delayed fluorescence or immediate fluorescence) and delayed fluorescence. In embodiments, an energy difference (ΔEST) between the lowest singlet excited state (S1) and the lowest triplet excited state (T1) of the exciplex host may be less than or equal to 0.2 eV. Both the prompt fluorescence and delayed fluorescence of the exciplex host may be used to form excitons of the triplet excited state of the first dopant.
The first dopant may transfer energy as a phosphorescent dopant-based sensitizer.
An energy difference (ΔEST) between the lowest singlet excited state (S1) and the lowest triplet excited state (T1) of the second dopant may be less than or equal to 0.2 eV, and the second dopant may be delayed fluorescence emitter.
The emission layer satisfies Conditions 1) to 3).
In Conditions 1) to 3),
According to Condition 1), the energy of the lowest triplet excited state (T1) of the exciplex host is greater than the energy of the lowest triplet excited state (T1) of the first dopant, and the energy of the lowest triplet excited state (T1) of the first dopant is greater than the energy of the lowest triplet excited state (T1) of the second dopant. Accordingly, the energy of the lowest triplet excitation energy level of the exciplex host is easily transferred to the lowest triplet excited states (T1) of the first dopant and the second dopant, and thus, the second dopant may emit delayed fluorescence.
Regarding Conditions 2) and 3), further description is provided with reference to
The luminescence, non-radiative decay, and intersystem crossing of the lowest singlet excited state (S1) may be respectively represented by a radiative rate constant krs, a non-radiative rate constant knrs, and an intersystem crossing rate constant kISC, and the non-radiative decay and reverse intersystem crossing of the lowest triplet excited state (T1) may be respectively represented by a non-radiative rate constant knrT and a reverse intersystem crossing rate constant kRISC.
Condition 2) may mean that the non-radiative rate constant knrs of the lowest singlet excited state (S1) of the exciplex host does not change (or does not substantially change) with temperature. This may mean that the excitons of the lowest singlet excited state do not affect device efficiency according to temperature. In the lowest singlet excited state (S1), radiative decay and non-radiative decay compete with each other, and thus, when the non-radiative rate constant does not change with temperature, the radiative rate constant also does not change with temperature. Therefore, decay curves of time-resolved photoluminescence of the prompt fluorescence of the exciplex host in a range from room temperature to 60° C. may overlap with each other.
Condition 3) means that as the temperature of the emission layer increases, the non-radiative decay of the excitons of the lowest triplet excited state (T1) of the exciplex host increases. When the lifespan of triplet excitons of the exciplex host is short, the device lifespan may be improved by reducing triplet excitons through Dexter energy transfer to the second dopant. When there is a longer device lifespan at high temperatures, it is beneficial for applications such as automotive displays.
In an embodiment, the interlayer may further include a hole transport region between the anode and the emission layer and including a hole injection layer, a hole transport layer, an electron blocking layer, or any combination thereof.
In an embodiment, the interlayer may further include an electron transport region between the cathode and the emission layer and including a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof.
In an embodiment, the first host may include a compound represented by Formula 1:
In an embodiment, R1, R2, and Ar1 may each independently be selected from hydrogen, deuterium, and Formulae 2a to 2c:
In an embodiment, L1 may be selected from Formulae 3a to 3c:
In an embodiment, the first host may include any one selected from Compounds HT-01 to HT-09:
In an embodiment, the second host may include a compound represented by Formula 2:
In Formula 2, L11 to L13 are each as described in connection with L1 in Formula 1.
In Formula 2, b11 to b13 may each independently be an integer from 0 to 3.
In an embodiment, Ar11 to Ar13 may each independently be selected from hydrogen, deuterium, and Formulae 4a to 4e:
In an embodiment, L11 to L13 may each independently be Formula 5a:
In an embodiment, the second host may include any one selected from Compounds ET01 to ET12:
In an embodiment, in the emission layer, the first host and the second host may have a weight ratio of 1:9 to 9:1.
For example, the first host and the second host may have a weight ratio of 3:7 to 7:3. The first host and the second host may have a weight ratio of 4:5 to 5:4.
When the weight ratio of the first host and the second host is within the above ranges, the balance of electrons and holes may be suitable or appropriate.
In an embodiment, the metal of the first dopant may be a transition metal.
In an embodiment, the first dopant may include an organometallic compound represented by Formula 401:
For example, in Formula 402, i) X401 may be nitrogen and X402 may be carbon, or ii) each of X401 and X402 may be nitrogen.
In an embodiment, when xc1 in Formula 401 is 2 or more, two of ring A401 among two or more of L401 may be optionally linked to each other via T402, which is a linking group, or two of ring A402 among two or more of L401 may be optionally linked to each other via T403, which is a linking group. T402 and T403 are each 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), an isonitrile group, a —CN group, a phosphorus group (for example, a phosphine group, a phosphite group, etc.), or any combination thereof.
In an embodiment, the first dopant may include one selected from Compounds 1 to 16:
In an embodiment, the second dopant may include a compound represented by Formula 4:
In an embodiment, the compound represented by Formula 4 may be represented by one selected from Formulae 4-1 and 4-2:
In an embodiment, R31a to R31d, R32a to R32d, R33a to R33c, R34a to R34d, R35a to R35c, R44, and R45 may each independently be selected from a C1-C60 alkyl group and Formulae 6a to 6c:
In an embodiment, the second dopant may include one selected from Compounds D-01 to D-12:
In an embodiment, the emission layer may be a fluorescent emission layer.
In an embodiment, the emission layer may be a blue emission layer.
According to one or more embodiments, there is provided an electronic apparatus including: a thin-film transistor; and the light-emitting device, wherein the thin-film transistor includes a source electrode, a drain electrode, an activation layer, and a gate electrode, and the first electrode of the light-emitting device is electrically connected to one selected from the source electrode and the drain electrode of the thin-film transistor.
The term “organic layer” as used herein refers to a single layer and/or all layers between the first electrode and the second electrode of the organic light-emitting device. A material included in the “organic layer” is not limited to an organic material.
Hereinafter, a structure of the light-emitting device 10 according to an embodiment and a method of manufacturing the light-emitting device 10 are described with reference to
In
The first electrode 110 may be formed by, for example, depositing and/or sputtering a material for forming the first electrode 110 on the substrate. When the first electrode 110 is an anode, a material for forming the first electrode 110 may be a high-work function material that facilitates injection of holes.
The first electrode 110 may be a reflective electrode, a semi-transmissive electrode, or a transmissive electrode. When the first electrode 110 is a transmissive electrode, a material for forming the first electrode 110 may include indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO2), zinc oxide (ZnO), or any combination thereof. In an embodiment, 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 (AI), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), or any combination thereof.
The first electrode 110 may have a single-layer structure consisting of a single layer or a multilayer structure including a plurality of layers. In an embodiment, the first electrode 110 may have a three-layer structure of ITO/Ag/ITO.
The interlayer 130 is on the first electrode 110. The interlayer 130 may include the emission layer.
The interlayer 130 may further include a hole transport region between the first electrode 110 and the emission layer, and an electron transport region between the emission layer and the second electrode 150.
The interlayer 130 may further include, in addition to various suitable organic materials, a metal-containing compound such as an organometallic compound, an inorganic material such as quantum dots, and/or the like.
In an embodiment, the interlayer 130 may include i) two or more emitting units sequentially between the first electrode 110 and the second electrode 150, and ii) a charge generation layer between the two or more emitting units. When the interlayer 130 includes emitting units and a charge generation layer as described above, the light-emitting device 10 may be a tandem light-emitting device.
The hole transport region may have: i) a single-layer structure consisting of a single layer consisting of a single material, ii) a single-layer structure consisting of a single layer consisting of a plurality of materials that are different from each other, or iii) a multilayer structure including a plurality of layers including a plurality of materials that are different from each other.
The hole transport region may include a hole injection layer, a hole transport layer, an emission auxiliary layer, an electron blocking layer, or any combination thereof.
In an embodiment, the hole transport region may have a multilayer structure including a hole injection layer/hole transport layer structure, a hole injection layer/hole transport layer/emission auxiliary layer structure, a hole 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 constituent layers of each structure are provided sequentially from the first electrode 110.
The hole transport region may include a compound represented by Formula 201, a compound represented by Formula 202, or any combination thereof:
na1 may be an integer from 1 to 4.
In an embodiment, each of Formulae 201 and 202 may include at least one selected from groups represented by Formulae CY201 to CY217:
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 an embodiment, each of Formulae 201 and 202 may include at least one selected from groups represented by Formulae CY201 to CY203.
In an embodiment, Formula 201 may include at least one selected from groups represented by Formulae CY201 to CY203 and at least one selected from groups represented by Formulae CY204 to CY217.
In an embodiment, in Formula 201, xa1 may be 1, R201 may be a group represented by one selected from Formulae CY201 to CY203, xa2 may be 0, and R202 may be a group represented by one selected from Formulae CY204 to CY207.
In an embodiment, each of Formulae 201 and 202 may not include groups represented by Formulae CY201 to CY203.
In an embodiment, each of Formulae 201 and 202 may not include groups represented by Formulae CY201 to CY203 and may include at least one selected from groups represented by Formulae CY204 to CY217.
In an embodiment, each of Formulae 201 and 202 may not include groups represented by Formulae CY201 to CY217.
In an embodiment, the hole transport region may include one selected from Compounds HT1 to HT46, m-MTDATA, TDATA, 2-TNATA, NPB(NPD), β-NPB, TPD, Spiro-TPD, Spiro-NPB, methylated-NPB, TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA), polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA), poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS), polyaniline/camphor sulfonic acid (PANI/CSA), polyaniline/poly(4-styrenesulfonate) (PANI/PSS), or any combination thereof:
The thickness of the hole transport region may be 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, the thickness of the hole injection layer may be about 10 Å to about 9,000 Å, for example, about 10 Å to about 1,000 Å, and the thickness of the hole transport layer may be 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 the ranges described above, suitable or satisfactory hole transporting characteristics may be obtained without a substantial increase in driving voltage.
The emission auxiliary layer may increase light-emission efficiency by compensating for an optical resonance distance of 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.
p-Dopant
The hole transport region may further include, in addition to the foregoing materials, a charge-generation material for the improvement of conductive properties (e.g., electrically conductive properties). The charge-generation material may be uniformly or non-uniformly dispersed in the hole transport region (for example, in the form of a single layer consisting of a charge-generation material).
The charge-generation material may be, for example, a p-dopant.
For example, the LUMO energy of the p-dopant may be less than or equal to −3.5 eV.
In an embodiment, the p-dopant may include a quinone derivative, a cyano group-containing compound, a compound including an element EL1 and an element EL2, or any combination thereof.
Examples of the quinone derivative may include TCNQ and F4-TCNQ.
Examples of the cyano group-containing compound may include HAT-CN and a compound represented by Formula 221.
In Formula 221,
In the compound including the element EL1 and the element EL2, the element EL1 may be a metal, a metalloid, or a combination thereof, and the element EL2 may be a non-metal, a metalloid, or a combination thereof.
Examples of the metal may include an alkali metal (for example, lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), etc.); an alkaline earth metal (for example, beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), etc.); a transition metal (for example, titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), technetium (Tc), rhenium (Re), iron (Fe), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu), silver (Ag), gold (Au), etc.); a post-transition metal (for example, zinc (Zn), indium (In), tin (Sn), etc.); and a lanthanide metal (for example, lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), etc.).
Examples of the metalloid may include silicon (Si), antimony (Sb), and tellurium (Te).
Examples of the non-metal may include oxygen (O) and halogen (for example, F, Cl, Br, I, etc.).
Examples of the compound including the element EL1 and the element EL2 may include a metal oxide, a metal halide (for example, a metal fluoride, a metal chloride, a metal bromide, a metal iodide, etc.), a metalloid halide (for example, a metalloid fluoride, a metalloid chloride, a metalloid bromide, a metalloid iodide, etc.), a metal telluride, or any combination thereof.
Examples of the metal oxide may include a tungsten oxide (for example, WO, W2O3, WO2, WO3, W2O5, etc.), a vanadium oxide (for example, VO, V2O3, VO2, V2O5, etc.), a molybdenum oxide (MoO, Mo2O3, MoO2, MoO3, Mo2O5, etc.), and a rhenium oxide (for example, ReO3, etc.).
Examples of the metal halide may include an alkali metal halide, an alkaline earth metal halide, a transition metal halide, a post-transition metal halide, and a lanthanide metal halide.
Examples of the alkali metal halide may include LiF, NaF, KF, RbF, CsF, LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI, RbI, and CsI.
Examples of the alkaline earth metal halide may include BeF2, MgF2, CaF2, SrF2, BaF2, BeCl2, MgCl2, CaCl2, SrCl2, BaCl2, BeBr2, MgBr2, CaBr2, SrBr2, BaBr2, BeI2, MgI2, CaI2, SrI2, and BaI2.
Examples of the transition metal halide may include a titanium halide (for example, TiF4, TiC4, TiBr4, TiI4, etc.), a zirconium halide (for example, ZrF4, ZrCl4, ZrBr4, ZrI4, etc.), a hafnium halide (for example, HfF4, HfCl4, HfBr4, HfI4, etc.), a vanadium halide (for example, VF3, VCI3, VBr3, VI3, etc.), a niobium halide (for example, NbF3, NbCl3, NbBr3, NbI3, etc.), a tantalum halide (for example, TaF3, TaCl3, TaBr3, TaI3, etc.), a chromium halide (for example, CrF3, CrCl3, CrBr3, CrI3, etc.), a molybdenum halide (for example, MoF3, MoCl3, MoBr3, MoI3, etc.), a tungsten halide (for example, WF3, WCI3, WBr3, WI3, etc.), a manganese halide (for example, MnF2, MnCl2, MnBr2, MnI2, etc.), a technetium halide (for example, TcF2, TcCl2, TcBr2, TcI2, etc.), a rhenium halide (for example, ReF2, ReCl2, ReBr2, ReI2, etc.), an iron halide (for example, FeF2, FeCl2, FeBr2, FeI2, etc.), a ruthenium halide (for example, RuF2, RuCl2, RuBr2, RuI2, etc.), an osmium halide (for example, OsF2, OsCl2, OsBr2, OsI2, etc.), a cobalt halide (for example, CoF2, COCl2, CoBr2, CoI2, etc.), a rhodium halide (for example, RhF2, RhCl2, RhBr2, RhI2, etc.), an iridium halide (for example, IrF2, IrCl2, IrBr2, IrI2, etc.), a nickel halide (for example, NiF2, NiCl2, NiBr2, NiI2, etc.), a palladium halide (for example, PdF2, PdCl2, PdBr2, PdI2, etc.), a platinum halide (for example, PtF2, PtCl2, PtBr2, PtI2, etc.), a copper halide (for example, CuF, CuCl, CuBr, CuI, etc.), a silver halide (for example, AgF, AgCl, AgBr, AgI, etc.), and a gold halide (for example, AuF, AuCl, AuBr, AuI, etc.).
Examples of the post-transition metal halide may include a zinc halide (for example, ZnF2, ZnCl2, ZnBr2, ZnI2, etc.), an indium halide (for example, InI3, etc.), and a tin halide (for example, SnI2, etc.).
Examples of the lanthanide metal halide may include YbF, YbF2, YbF3, SmF3, YbCl, YbCl2, YbCl3, SmCl3, YbBr, YbBr2, YbBr3, SmBr3, YbI, YbI2, YbI3, and SmI3.
Examples of the metalloid halide may include an antimony halide (for example, SbCl5, etc.).
Examples of the metal telluride may include an alkali metal telluride (for example, Li2Te, Na2Te, K2Te, Rb2Te, Cs2Te, etc.), an alkaline earth metal telluride (for example, BeTe, MgTe, CaTe, SrTe, BaTe, etc.), a transition metal telluride (for example, TiTe2, ZrTe2, HfTe2, V2Te3, Nb2Te3, Ta2Te3, Cr2Te3, Mo2Te3, W2Te3, MnTe, TcTe, ReTe, FeTe, RuTe, OsTe, CoTe, RhTe, IrTe, NiTe, PdTe, PtTe, Cu2Te, CuTe, Ag2Te, AgTe, Au2Te, etc.), a post-transition metal telluride (for example, ZnTe, etc.), and a lanthanide metal telluride (for example, LaTe, CeTe, PrTe, NdTe, PmTe, EuTe, GdTe, TbTe, DyTe, HoTe, ErTe, TmTe, YbTe, LuTe, etc.
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 (e.g., spaced apart) 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 together with each other in a single layer, to emit white light.
The emission layer may include a host and a dopant. The dopant may include a phosphorescent dopant, a fluorescent dopant, or any combination thereof.
The amount of the dopant in the emission layer may be generally about 0.01 parts by weight to about 15 parts by weight based on 100 parts by weight of the host.
In an embodiment, the emission layer may include a quantum dot.
In an embodiment, 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.
The thickness of the emission layer may be 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 the ranges described above, excellent luminescence characteristics may be obtained without a substantial increase in driving voltage.
The host may include the first host and the second host.
The host may further include, for example, in addition to the first host and the second host, a compound represented by Formula 301.
[Ar301]xb11-[(L301)xb1-R301]xb21 Formula 301
In Formula 301,
In an embodiment, when xb11 in Formula 301 is 2 or more, two or more of Ar301 may be linked to each other via a single bond (e.g., a single covalent bond).
In an embodiment, the host may include a compound represented by Formula 301-1, a compound represented by Formula 301-2, or any combination thereof:
In an embodiment, the host may include an alkali earth metal complex, a post-transition metal complex, or any combination thereof. In an embodiment, the host may include a Be complex (for example, Compound H55), an Mg complex, a Zn complex, or any combination thereof.
In an embodiment, the host may include: one selected from Compounds H1 to H128; 9,10-di(2-naphthyl)anthracene (ADN); 2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN); 9,10-di-(2-naphthyl)-2-t-butyl-anthracene (TBADN); 4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP);1,3-di-9-carbazolylbenzene (mCP); 1,3,5-tri(carbazol-9-yl)benzene (TCP); or any combination thereof:
The first dopant may include a phosphorescent dopant.
In an embodiment, the amount of the first dopant may be about 1 wt % to about 15 wt % (based on 100 parts by weight of the total hosts). When the amount of the first dopant is within the range above, the light-emitting device may have excellent efficiency and lifespan.
The emission layer may include a delayed fluorescence material.
The second dopant may include a delayed fluorescence material.
In an embodiment, the amount of the second dopant may be about 0.5 wt % to about 2.5 wt % (based on 100 parts by weight of the total hosts). When the amount of the second dopant is within the range above, the light-emitting device may have excellent efficiency and lifespan.
The electron transport region may have: i) a single-layered structure consisting of a single layer consisting of a single material, ii) a single-layered structure consisting of a single layer including a plurality of different materials, or iii) a multilayer structure including a plurality of layers including a plurality of different materials.
The electron transport region may include a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof.
For example, the electron transport region may have a structure including an electron transport layer/electron injection layer structure or a hole blocking layer/electron transport layer/electron injection layer structure, wherein in each structure, constituting layers are sequentially provided from the emission layer.
The electron transport region (for example, a hole blocking layer and/or an electron transport layer in the electron transport region) may include a metal-free compound including at least one π electron-deficient nitrogen-containing C1-C60 cyclic group.
In an embodiment, the electron transport region may include a compound represented by Formula 601.
[Ar601]xe11-[(L601)xe1-R601]xe21 Formula 601
In Formula 601,
In an embodiment, when xe11 in Formula 601 is 2 or more, two or more of Ar601 may be linked together via a single bond (e.g., a single covalent bond).
In an embodiment, Ar601 in Formula 601 may be a substituted or unsubstituted anthracene group.
In an embodiment, the electron transport region may include a compound represented by Formula 601-1:
In an embodiment, xe1 and xe611 to xe613 in Formulae 601 and 601-1 may each independently be 0, 1, or 2.
The electron transport region may include one selected from Compounds ET1 to ET45, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), alq3, BAlq, TAZ, NTAZ, or any combination thereof:
The thickness of the electron transport region may be 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 hole blocking layer, an electron transport layer, or any combination thereof, the thickness of the hole blocking layer or the electron transport layer may be about 20 Å to about 1,000 Å, for example, about 30 Å to about 300 Å. The thickness of the electron transport layer may be about 100 Å to about 1,000 Å, for example, about 150 Å to about 500 Å. When the thicknesses of the hole blocking layer and/or the electron transport layer are within these ranges as described above, suitable or satisfactory electron transporting characteristics may be obtained without a substantial increase in driving voltage.
The electron transport region (for example, the electron transport layer in the electron transport region) may further include, in addition to the materials described above, a metal-containing material.
The metal-containing material may include an alkali metal complex, an alkaline earth metal complex, or any combination thereof. A metal ion of the alkali metal complex may be a Li ion, a Na ion, a K ion, a Rb ion, and/or a Cs ion, and a metal ion of the alkaline earth metal complex may be a Be ion, a Mg ion, a Ca ion, a Sr ion, and/or a Ba ion. A ligand coordinated with the metal ion of the alkali metal complex and/or the alkaline earth-metal complex may include a hydroxyquinoline, a hydroxyisoquinoline, a hydroxybenzoquinoline, a hydroxyacridine, a hydroxyphenanthridine, a hydroxyphenyloxazole, a hydroxyphenylthiazole, a hydroxyphenyloxadiazole, a hydroxyphenylthiadiazole, a hydroxyphenylpyridine, a hydroxyphenylbenzimidazole, a hydroxyphenylbenzothiazole, a bipyridine, a phenanthroline, a cyclopentadiene, or any combination thereof.
In an embodiment, the metal-containing material may include a Li complex. The Li complex may include, for example, Compound ET-D1 (LiQ) and/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 consisting of a single layer consisting of a single material, ii) a single-layered structure consisting of a single layer including a plurality of different materials, or iii) a multilayer structure including a plurality of layers including a plurality of different materials.
The electron injection layer may include an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal-containing compound, an alkaline earth metal-containing compound, a rare earth metal-containing compound, an alkali metal complex, an alkaline earth metal complex, a rare earth metal complex, or any combination thereof.
The alkali metal may include Li, Na, K, Rb, Cs, or any combination thereof. The alkaline earth metal may include Mg, Ca, Sr, Ba, or any combination thereof. The rare earth metal may include Sc, Y, Ce, Tb, Yb, Gd, or any combination thereof.
The alkali metal-containing compound, the alkaline earth metal-containing compound, and the rare earth metal-containing compound may include oxides, halides (for example, fluorides, chlorides, bromides, iodides, etc.), and/or tellurides of the alkali metal, the alkaline earth metal, and/or the rare earth metal, or any combination thereof.
The alkali metal-containing compound may include: alkali metal oxides, such as Li2O, Cs2O, and/or K2O; alkali metal halides, such as LiF, NaF, CsF, KF, LiI, NaI, CsI, and/or KI; or any combination thereof. The alkaline earth metal-containing compound may include an alkaline earth metal compound, such as BaO, SrO, CaO, BaxSr1-xO (x is a real number satisfying 0<x<1), and/or BaxCa1-xO (x is a real number satisfying 0<x<1). The rare earth metal-containing compound may include YbF3, ScF3, Sc2O3, Y2O3, Ce2O3, GdF3, TbF3, Ybl3, Scl3, TbI3, or any combination thereof. In an embodiment, the rare earth metal-containing compound may include lanthanide metal telluride. Examples of the lanthanide metal telluride may include LaTe, CeTe, PrTe, NdTe, PmTe, SmTe, EuTe, GdTe, TbTe, DyTe, HoTe, ErTe, TmTe, YbTe, LuTe, La2Te3, Ce2Te3, Pr2Te3, Nd2Te3, Pm2Te3, Sm2Te3, Eu2Te3, Gd2Te3, Tb2Te3, Dy2Te3, Ho2Te3, Er2Te3, Tm2Te3, Yb2Te3, and Lu2Te3.
The alkali metal complex, the alkaline earth-metal complex, and the rare earth metal complex may include i) one of 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 any combination thereof.
The electron injection layer may consist of an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal-containing compound, an alkaline earth metal-containing compound, a rare earth metal-containing compound, an alkali metal complex, an alkaline earth metal complex, a rare earth metal complex, or any combination thereof, as described above. In an embodiment, the electron injection layer may further include an organic material (for example, a compound represented by Formula 601).
In an embodiment, the electron injection layer may consist of i) an alkali metal-containing compound (for example, alkali metal halide), ii) a) an alkali metal-containing compound (for example, alkali metal halide); and b) an alkali metal, an alkaline earth metal, a rare earth metal, or any combination thereof. In an embodiment, the electron injection layer may be a KI:Yb co-deposited layer, an RbI:Yb co-deposited layer, a LiF:Yb co-deposited layer, and/or the like.
When the electron injection layer further includes an organic material, the alkali metal, the alkaline earth metal, the rare earth metal, the alkali metal-containing compound, the alkaline earth metal-containing compound, the rare earth metal-containing compound, the alkali metal complex, the alkaline earth-metal complex, the rare earth metal complex, or any combination thereof may be uniformly or non-uniformly dispersed in a matrix including the organic material.
The thickness of the electron injection layer may be 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 range as described above, suitable or satisfactory electron injection characteristics may be obtained without a substantial increase in driving voltage.
The second electrode 150 is on the interlayer 130. The second electrode 150 may be a cathode, which is an electron injection electrode, and as a material for forming the second electrode 150, a metal, an alloy, an electrically conductive compound, or any combination thereof, each having a low-work function, may be used.
The second electrode 150 may include lithium (Li), silver (Ag), magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), ytterbium (Yb), silver-ytterbium (Ag—Yb), ITO, IZO, or any combination thereof. The second electrode 150 may be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode.
The second electrode 150 may have a single-layer structure or a multilayer structure including a plurality of layers.
A first capping layer may be outside the first electrode 110, and/or a second capping layer may be outside the second electrode 150. In embodiments, 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 provided 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 provided 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 provided in the stated order.
Light generated in the 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 the 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, such that the luminescence efficiency of the light-emitting device 10 may be 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 a 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 selected from the first capping layer and the second capping layer may each independently include a carbocyclic compound, a heterocyclic compound, an amine group-containing compound, a porphine derivative, a phthalocyanine derivative, a naphthalocyanine derivative, an alkali metal complex, an alkaline earth metal complex, or any combination thereof. The carbocyclic compound, the heterocyclic compound, and the amine group-containing compound may optionally be substituted with a substituent including O, N, S, Se, Si, F, Cl, Br, I, or any combination thereof. In an embodiment, at least one selected from the first capping layer and the second capping layer may each independently include an amine group-containing compound.
In an embodiment, 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 one selected from Compounds HT28 to HT33, one selected from Compounds CP1 to CP6, β-NPB, or any combination thereof:
The light-emitting device may be included in various 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 provided 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. A detailed description of the light-emitting device is provided above. In an embodiment, the color conversion layer may include quantum dots.
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 provided 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 provided among the color filter areas, and the color conversion layer may further include a plurality of color conversion areas and light-shielding patterns provided among the color conversion areas.
The plurality of color filter areas (or the plurality of color conversion areas) may include a first area that emits a first color light, a second area that emits a second color light, and/or a third area that emits a third color light, wherein the first color light, the second color light, and/or the third color light may have different maximum emission wavelengths. In an embodiment, 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. In an embodiment, the plurality of color filter areas (or the plurality of color conversion areas) may include quantum dots. In more detail, the first area may include red quantum dots, the second area may include green quantum dots, and the third area may not include quantum dots. A detailed description of the quantum dots is provided herein. The first area, the second area, and/or the third area may each further include a scatterer (e.g., a light scatterer).
In an embodiment, the light-emitting device may emit a first light, the first area may absorb the first light to emit a first-1 color light, the second area may absorb the first light to emit a second-1 color light, and the third area may absorb the first light to emit a third-1 color light. In embodiments, the first-1 color light, the second-1 color light, and the third-1 color light may have different maximum emission wavelengths. In more detail, the first light may be blue light, the first-1 color light may be red light, the second-1 color light may be green light, and the third-1 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 any one selected from the source electrode and the drain electrode may be electrically connected to any one selected from the first electrode and the second electrode of the light-emitting device.
The thin-film transistor may further include a gate electrode, a gate insulating film, and/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 that seals the light-emitting device. The sealing portion may be provided between the color filter and/or the color conversion layer and the light-emitting device. The sealing portion allows light from the light-emitting device to be extracted to the outside, and concurrently (or simultaneously) prevents or reduces penetration of ambient air and/or moisture 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 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 and/or a polarizing layer. The touch screen layer may be a pressure-sensitive touch screen layer, a capacitive touch screen layer, and/or an infrared touch screen layer. The authentication apparatus may be, for example, a biometric authentication apparatus that authenticates an individual by using biometric information of a living body (for example, fingertips, pupils, etc.).
The authentication apparatus may further include, in addition to the light-emitting device as described above, a biometric information collector.
The electronic apparatus may be applied to various 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, and/or endoscope displays), fish finders, various measuring instruments, meters (for example, meters for a vehicle, an aircraft, and/or a vessel), projectors, and/or the like.
The electronic apparatus of
The substrate 100 may be a flexible substrate, a glass substrate, and/or a metal substrate. A buffer layer 210 may be 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 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 and/or polysilicon, an organic semiconductor, and/or an oxide semiconductor, and may include a source region, a drain region, and a channel region.
A gate insulating film 230 for insulating (e.g., electrically insulating) the activation layer 220 from the gate electrode 240 may be on the activation layer 220, and the gate electrode 240 may be on the gate insulating film 230.
An interlayer insulating film 250 may be on the gate electrode 240. The interlayer insulating film 250 may be between the gate electrode 240 and the source electrode 260 and between the gate electrode 240 and the drain electrode 270, to insulate (e.g., electrically insulate) from one another.
The source electrode 260 and the drain electrode 270 may be on the interlayer insulating film 250. The interlayer insulating film 250 and the gate insulating film 230 may expose the source region and the drain region of the activation layer 220, and the source electrode 260 and the drain electrode 270 may be in contact with the exposed portions of the source region and the drain region of the activation layer 220.
The TFT may be electrically connected to a light-emitting device to drive the light-emitting device, and may be covered and protected by a passivation layer 280. The passivation layer 280 may include an inorganic insulating film, an organic insulating film, or any combination thereof. A light-emitting device may be provided on the passivation layer 280. The light-emitting device may include the first electrode 110, the interlayer 130, and the second electrode 150.
The first electrode 110 may be on the passivation layer 280. The passivation layer 280 may expose a portion of the drain electrode 270, not fully cover the drain electrode 270, and the first electrode 110 may be connected to the exposed portion of the drain electrode 270.
A pixel-defining film 290 including an insulating material (e.g., an electrically insulating material) may be on the first electrode 110. The pixel-defining film 290 may expose a certain region of the first electrode 110, and the interlayer 130 may be in the exposed region of the first electrode 110. The pixel-defining film 290 may be a polyimide-based organic film and/or a polyacrylic organic film. In embodiments, at least some layers of the interlayer 130 may extend beyond the upper portion of the pixel-defining film 290 and may thus be in the form of a common layer.
The second electrode 150 may be on the interlayer 130, and a capping layer 170 may be additionally on the second electrode 150. The capping layer 170 may cover the second electrode 150.
The encapsulation portion 300 may be on the capping layer 170. The encapsulation portion 300 may be on a light-emitting device to protect the light-emitting device from 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 any combination thereof; an organic film including polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, polyethylene sulfonate, polyoxymethylene, polyarylate, hexamethyldisiloxane, an acrylic resin (for example, polymethyl methacrylate, polyacrylic acid, and/or the like), an epoxy-based resin (for example, aliphatic glycidyl ether (AGE), and/or the like), or any combination thereof; or a combination of the inorganic film and the organic film.
The electronic apparatus of
The layers constituting the hole transport region, the emission layer, and the layers constituting the electron transport region may be formed in a certain region by using various 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 the layers constituting the hole transport region, the emission layer, and the layers constituting the electron transport region are formed by vacuum deposition, the deposition may be performed at a deposition temperature in a range of about 100° C. to about 500° C., at a vacuum degree in a range of about 10−8 torr to about 10−3 torr, and at a deposition speed in a range of about 0.01 Å/sec to about 100 Å/sec, depending on a material to be included in a layer to be formed and the structure of a layer to be formed.
The term “C3-C60 carbocyclic group” as used 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 used herein refers to a cyclic group that has one to sixty carbon atoms and further includes, in addition to the carbon atoms, 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 together with each other. In an embodiment, the number of ring-forming atoms of the C1-C60 heterocyclic group may be 3 to 61.
The “cyclic group” as used herein may include both the C3-C60 carbocyclic group and the C1-C60 heterocyclic group.
The term “π electron-rich C3-C60 cyclic group” as used herein 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 used herein refers to a heterocyclic group that has one to sixty carbon atoms and includes *—N=*′ as a ring-forming moiety.
In an embodiment,
Group T1 may be a cyclopropane group, a cyclobutane group, a cyclopentane group, a cyclohexane group, a cycloheptane group, a cyclooctane group, a cyclobutene group, a cyclopentene group, a cyclopentadiene group, a cyclohexene group, a cyclohexadiene group, a cycloheptene group, an adamantane group, a norbornane (or bicyclo[2.2.1]heptane) group, a norbornene group, a bicyclo[1.1.1]pentane group, a bicyclo[2.1.1]hexane group, a bicyclo[2.2.2]octane group, or a benzene group,
Group T2 may be a furan group, a thiophene group, a 1H-pyrrole group, a silole group, a borole group, a 2H-pyrrole group, a 3H-pyrrole group, an imidazole group, a pyrazole group, a triazole group, a tetrazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, an azasilole group, an azaborole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a tetrazine group, a pyrrolidine group, an imidazolidine group, a dihydropyrrole group, a piperidine group, a tetrahydropyridine group, a dihydropyridine group, a hexahydropyrimidine group, a tetrahydropyrimidine group, a dihydropyrimidine group, a piperazine group, a tetrahydropyrazine group, a dihydropyrazine group, a tetrahydropyridazine group, or a dihydropyridazine group,
Group T3 may be a furan group, a thiophene group, a 1H-pyrrole group, a silole group, or a borole group, and
Group T4 may be a 2H-pyrrole group, a 3H-pyrrole group, an imidazole group, a pyrazole group, a triazole group, a tetrazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, an azasilole group, an azaborole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, or a tetrazine group.
The terms “cyclic group”, “C3-C60 carbocyclic group”, “C1-C60 heterocyclic group”, “π electron-rich C3-C60 cyclic group”, or “π electron-deficient nitrogen-containing C1-C60 cyclic group” as used herein may 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, etc.) according to the structure of a formula for which the corresponding term is used. In an embodiment, the “benzene group” may be a benzo group, a phenyl group, a phenylene group, or the like, which may be easily understood by those of ordinary skill in the art according to the structure of a formula including the “benzene group.”
For example, examples of a monovalent C3-C60 carbocyclic group and a monovalent C1-C60 heterocyclic group may include a C3-C10 cycloalkyl group, a C1-C10 heterocycloalkyl group, a C3-C10 cycloalkenyl group, a C1-C10 heterocycloalkenyl group, a C6-C60 aryl group, a C1-C60 heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group, and examples of a divalent C3-C60 carbocyclic group and a divalent C1-C60 heterocyclic group may include a C3-C10 cycloalkylene group, a C1-C10 heterocycloalkylene group, a C3-C10 cycloalkenylene group, a C1-C10 heterocycloalkenylene group, a C6-C60 arylene group, a C1-C60 heteroarylene group, a divalent non-aromatic condensed polycyclic group, and a divalent non-aromatic condensed heteropolycyclic group.
The term “C1-C60 alkyl group” as used herein refers to a linear or branched aliphatic hydrocarbon monovalent group that has one to sixty carbon atoms, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a tert-pentyl group, a neopentyl group, an isopentyl group, a sec-pentyl group, a 3-pentyl group, a sec-isopentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isooctyl group, a sec-octyl group, a tert-octyl group, an n-nonyl group, an isononyl group, a sec-nonyl group, a tert-nonyl group, an n-decyl group, an isodecyl group, a sec-decyl group, and a tert-decyl group. The term “C1-C60 alkylene group” as used herein refers to a divalent group having the same structure as the C1-C60 alkyl group.
The term “C2-C60 alkenyl group” as used herein refers to a monovalent hydrocarbon group having at least one carbon-carbon double bond in a main chain (e.g., the middle) or at a terminal end (e.g., the terminus) of the C2-C60 alkyl group, and examples thereof include an ethenyl group, a propenyl group, and a butenyl group. The term “C2-C60 alkenylene group” as used herein refers to a divalent group having the same structure as the C2-C60 alkenyl group.
The term “C2-C60 alkynyl group” as used herein refers to a monovalent hydrocarbon group having at least one carbon-carbon triple bond in a main chain (e.g., the middle) or at a terminal end (e.g., the terminus) of the C2-C60 alkyl group, and examples thereof include an ethynyl group, a propynyl group, etc. The term “C2-C60 alkynylene group” as used herein refers to a divalent group having the same structure as the C2-C60 alkynyl group.
The term “C1-C60 alkoxy group” as used 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 used herein refers to a monovalent saturated hydrocarbon cyclic group having 3 to 10 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantyl group, a norbornyl group (or bicyclo[2.2.1]heptyl group), a bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl group, a bicyclo[2.2.2]octyl group, etc. The term “C3-C10 cycloalkylene group” as used herein refers to a divalent group having the same structure as the C3-C10 cycloalkyl group.
The term “C1-C1 heterocycloalkyl group” as used herein refers to a monovalent cyclic group that has one to ten carbon atoms and further includes, in addition to the carbon atoms, at least one heteroatom as a ring-forming atom, and examples thereof include a 1,2,3,4-oxatriazolidinyl group, a tetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term “C1-C1 heterocycloalkylene group” as used herein refers to a divalent group having the same structure as the C1-C10 heterocycloalkyl group.
The term “C3-C10 cycloalkenyl group” as used 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 (e.g., is not aromatic), and examples thereof include a cyclopentenyl group, a cyclohexenyl group, and a cycloheptenyl group. The term “C3-C10 cycloalkenylene group” as used herein refers to a divalent group having the same structure as the C3-C10 cycloalkenyl group.
The term “C1-C10 heterocycloalkenyl group” as used herein refers to a monovalent cyclic group that has one to ten carbon atoms, further includes, in addition to the carbon atoms, at least one heteroatom as a ring-forming atom, and has at least one double bond in the ring thereof. Examples of the C1-C10 heterocycloalkenyl group include a 4,5-dihydro-1,2,3,4-oxatriazolyl group, a 2,3-dihydrofuranyl group, and a 2,3-dihydrothiophenyl group. The term “C1-C1 heterocycloalkenylene group” as used herein refers to a divalent group having the same structure as the C1-C1 heterocycloalkenyl group.
The term “C6-C60 aryl group” as used herein refers to a monovalent group having a carbocyclic aromatic system of six to sixty carbon atoms, and the term “C6-C60 arylene group” as used herein refers to a divalent group having a carbocyclic aromatic system of six to sixty carbon atoms. Examples of the C6-C60 aryl group include a phenyl group, a pentalenyl group, a naphthyl group, an azulenyl group, an indacenyl group, an acenaphthyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a heptalenyl group, a naphthacenyl group, a picenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, and an ovalenyl group. When the C6-C60 aryl group and the C6-C60 arylene group each include two or more rings, the two or more rings may be condensed with each other.
The term “C1-C60 heteroaryl group” as used herein refers to a monovalent group having a heterocyclic aromatic system that has one to sixty carbon atoms and further includes, in addition to the carbon atoms, at least one heteroatom as a ring-forming atom. The term “C1-C60 heteroarylene group” as used herein refers to a divalent group having a heterocyclic aromatic system that has one to sixty carbon atoms and further includes, in addition to the carbon atoms, at least one heteroatom as a ring-forming atom. Examples of the C1-C60 heteroaryl group include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, a benzoquinolinyl group, an isoquinolinyl group, a benzoisoquinolinyl group, a quinoxalinyl group, a benzoquinoxalinyl group, a quinazolinyl group, a benzoquinazolinyl group, a cinnolinyl group, a phenanthrolinyl group, a phthalazinyl group, and a naphthyridinyl group. When the C1-C60 heteroaryl group and the C1-C60 heteroarylene group each include two or more rings, the two or more rings may be condensed with each other.
The term “monovalent non-aromatic condensed polycyclic group” as used herein refers to a monovalent group having two or more rings condensed together with each other, only carbon atoms (for example, eight to sixty carbon atoms) as ring-forming atoms, and no aromaticity in its molecular structure when considered as a whole (e.g., is not aromatic when considered as a whole). Examples of the monovalent non-aromatic condensed polycyclic group include an indenyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, an indenophenanthrenyl group, and an indeno anthracenyl group. The term “divalent non-aromatic condensed polycyclic group” as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed polycyclic group.
The term “monovalent non-aromatic condensed heteropolycyclic group” as used herein refers to a monovalent group that has two or more rings condensed with each other, further includes, in addition to carbon atoms (for example, one to sixty carbon atoms), at least one heteroatom as a ring-forming atom, and has no aromaticity in its molecular structure when considered as a whole (e.g., is not aromatic when considered as a whole). 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 naphthoindolyl group, an isoindolyl group, a benzoisoindolyl group, a naphthoisoindolyl group, a benzosilolyl group, a benzothiophenyl group, a benzofuranyl group, a carbazolyl group, a dibenzosilolyl group, a dibenzothiophenyl group, a dibenzofuranyl group, an azacarbazolyl group, an azafluorenyl group, an azadibenzosilolyl group, an azadibenzothiophenyl group, an azadibenzofuranyl group, a pyrazolyl group, an imidazolyl group, a triazolyl group, a tetrazolyl group, an oxazolyl group, an isoxazolyl group, a thiazolyl group, an isothiazolyl group, an oxadiazolyl group, a thiadiazolyl group, a benzopyrazolyl group, a benzimidazolyl group, a benzoxazolyl group, a benzothiazolyl group, a benzoxadiazolyl group, a benzothiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an imidazotriazinyl group, an imidazopyrazinyl group, an imidazopyridazinyl group, an indeno carbazolyl group, an indolocarbazolyl group, a benzofurocarbazolyl group, a benzothienocarbazolyl group, a benzosilolocarbazolyl group, a benzoindolocarbazolyl group, a benzocarbazolyl group, a benzonaphthofuranyl group, a benzonaphthothiophenyl group, a benzonaphthosilolyl group, a benzofurodibenzofuranyl group, a benzofurodibenzothiophenyl group, and a benzothienodibenzothiophenyl group. The term “divalent non-aromatic condensed heteropolycyclic group” as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed heteropolycyclic group.
The term “C6-C60 aryloxy group” as used herein refers to —OA102 (wherein A102 is the C6-C60 aryl group), and the term “C6-C60 arylthio group” as used herein refers to —SA103 (wherein A103 is the C6-C60 aryl group).
The term “C7-C60 arylalkyl group” as used herein refers to -A104A105 (wherein A104 is a C1-C54 alkylene group, and A105 is a C6-C59 aryl group), and the term “C2-C60 heteroarylalkyl group” as used herein refers to -A106A107 (wherein A106 is a C1-C59 alkylene group, and A107 is a C1-C59 heteroaryl group).
The term “R10a” as used herein may be:
The term “heteroatom” as used herein refers to any atom other than a carbon atom. Examples of the heteroatom include O, S, N, P, Si, B, Ge, Se, or any combination thereof.
The term “third-row transition metal” as used herein includes hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), and the like.
“Ph” as used herein refers to a phenyl group, “Me” as used herein refers to a methyl group, “Et” as used herein refers to an ethyl group, “ter-Bu” or “But” as used herein refers to a tert-butyl group, and “OMe” as used herein refers to a methoxy group.
The term “biphenyl group” as used herein refers to “a phenyl group that is substituted with a phenyl group.” The “biphenyl group” may be a substituted phenyl group having a C6-C60 aryl group as a substituent.
The “terphenyl group” as used herein refers to a “phenyl group that is substituted with a biphenyl group”. The “terphenyl group” may be a substituted phenyl group having, as a substituent, a C6-C60 aryl group that is substituted with a C6-C60 aryl group.
The maximum number of carbon atoms in the substituent definition is just an example. For example, the number 60 as the maximum number of carbon atoms in the C1-C60 alkyl group is an example, and the definition of an alkyl group is also equally applied to the C1-C20 alkyl group. The other cases are the s'me.
* and *′ as used herein, unless defined otherwise, each refer to a binding site to a neighboring atom in a corresponding formula.
Compound HT-07 as a first host and Compound ET06 as a second host were co-deposited on a quartz substrate at a weight ratio of 5:5 to form a thin film having a thickness of 400 Å.
The photoluminescence intensity of the thin film of Test Example 1 over time in the nanosecond time domain was measured at 25° C., 40° C., and 60° C. by using a streak camera (Hamamatsu, N2 laser, excitation wavelength of 377 nm, emission wavelength of 465 nm), and results thereof are shown in
Referring to
In addition, the photoluminescence intensity of the thin film of Test Example 1 in the microsecond time domain was measured at 25° C., 40° C., and 60° C. by using the above method, and results thereof are shown in
Excitons of the lowest triplet excited state of the exciplex host may undergo non-radiative decay to the ground state or may undergo reverse intersystem crossing to the lowest singlet excited state and then emit delayed fluorescence. Referring to the graph of
The photoluminescence quantum yield (PLQY) measured for the thin film of Test Example 1 is shown in Table 1. The photoluminescence quantum yield shown in Table 1 is expressed as the sum of the quantum yields of general fluorescence (prompt fluorescence) and delayed fluorescence.
Referring to Table 1, the photoluminescence efficiency of the thin film of Test Example 1 decreased as the temperature of the emission layer increased.
A thin film was formed in the same manner as in Test example 1, except that Compound HT-07 was used as a first host and Compound ET05 was used as a second host.
A thin film was formed in the same manner as in Test example 1, except that Compound HT-07 was used as a first host and Compound ET04 was used as a second host.
A thin film was formed in the same manner as in Test example 1, except that Compound HT-07 was used as a first host and Compound ET02 was used as a second host.
The time-resolved photoluminescence intensity of each of the thin films of Test Examples 1 to 4 in the microsecond domain was measured in the same manner as described above, the lifespan of excitons of the lowest triplet excited state of a host exciplex was calculated, and results thereof are shown in Table 2.
When the lifespan of excitons of the lowest triplet excited state is short, it means that reverse intersystem crossing from T1 to S1 is fast, whereas, when the lifespan of excitons of the lowest triplet excited state is long, it means that reverse intersystem crossing from T1 to S1 is slow.
As an anode, Corning ITO glass substrate (1,200 Λ) of 15 Ω/cm2 was cut to a size of 50 mm×50 mm×0.5 mm, sonicated with isopropyl alcohol and pure water each for 10 minutes, and then cleaned by irradiation of ultraviolet rays and exposure of ozone thereto for 10 minutes. The resultant glass substrate was loaded onto a vacuum deposition apparatus.
Compound m-MTDATA was vacuum-deposited on the substrate to form a hole injection layer having a thickness of 40 Å, and subsequently, NPB was vacuum-deposited thereon to form a hole transport layer having a thickness of 10 Å.
A host combination (Compound HT-07 as a first host, Compound ET06 as a second host) of Test Example 1, Compound 5 as a first dopant, and Compound D-02 as a second dopant were co-deposited on the hole transport layer at a weight ratio of 65%:25%:10%:1% to form an emission layer having a thickness of 200 Å.
Next, Compound ETL1 was formed on the emission layer to form an electron transport layer having a thickness of 300 Å.
Al was vacuum-deposited on the electron transport layer to form a cathode having a thickness of 1,200 Å, thereby completing the manufacture of a light-emitting device.
A light-emitting device was manufactured in the same manner as in Example 1, except that a host combination of Test example 2 was used as a first host and a second host in an emission layer.
A light-emitting device was manufactured in the same manner as in Example 1, except that a host combination of Test Example 3 was used as a first host and a second host in an emission layer.
A light-emitting device was manufactured in the same manner as in Example 1, except that a host combination of Test Example 4 was used as a first host and a second host in an emission layer.
The luminescence efficiency (Cd/A) at 1,000 nit and lifespan (LT95) of each of the light-emitting devices of Example 1 and Comparative Examples 1 to 3 were measured by using a Keithley MU236 and a luminance meter PR650, and results thereof are shown in Table 3. Lifespan (LT95) is a measure of the time taken for the luminance at each of 25° C. and 40° C. to reach 95% relative to the initial luminance, and is expressed as relative values (%) with respect to the lifespan (LT95) of Example 1 at 25° C.
Referring to Table 3, the lifespan of the light-emitting device of Example 1 at both 25° C. and 40° C. was better than the lifespan of the light-emitting devices of Comparative Examples 1 to 3.
The light-emitting device according to an embodiment has excellent efficiency and excellent lifespan.
It should be understood that embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments. While one or more embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined by the following claims, and equivalents thereof.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2023-0185077 | Dec 2023 | KR | national |
