Patent Application
20240279168
This application claims priority to and benefits of Korean Patent Application No. 10-2023-0014404 under 35 U.S.C. § 119, filed on Feb. 2, 2023, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference.
Embodiments relate to a ligand compound and an inorganic nanoparticle-complex including the same.
A light-emitting device is a device having a property of converting electrical energy into light energy. Examples of such a light-emitting device include an organic light-emitting device in which a luminescent material is an organic material, a quantum light-emitting device in which a luminescent material is a quantum dot, etc.
A light-emitting device may have a structure in which a first electrode (or second electrode) is arranged on a substrate, and a hole transport region, an emission layer, an electron transport region, and a second electrode (or first electrode) are sequentially formed from the first electrode (or second electrode). Holes provided from the first electrode (or second electrode) may move toward the emission layer through the hole transport region, and electrons provided from the second electrode (or first electrode) may move toward the emission layer through the electron transport region. Carriers, such as holes and electrons, recombine in the emission layer to produce light.
It is to be understood that this background of the technology section is, in part, intended to provide useful background for understanding the technology. However, this background of the technology section may also include ideas, concepts, or recognitions that were not part of what was known or appreciated by those skilled in the pertinent art prior to a corresponding effective filing date of the subject matter disclosed herein.
Embodiments include a ligand compound and a device having improved efficiency.
Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the embodiments of the disclosure.
Embodiments provide a ligand compound which may be represented by Formula 1:
In Formula 1,
According to an embodiment, in Formula 1, a length of R2 may be greater than a length of R3.
According to an embodiment, in Formula 1, a length of R2 may be greater than a length of R1.
According to an embodiment, in Formula 1, a length of R1 may be greater than a length of R3.
According to an embodiment, the alkoxysilane group may be —Si(Q1)(Q2)(Q3), and Q1 to Q3 may each independently be a C1-C60 alkoxy group.
According to an embodiment, the ligand compound represented by Formula 1 may be one of Compounds 1 to 8, which are described below.
Embodiments provide an inorganic nanoparticle-complex which may include an inorganic nanoparticle; and the ligand compound,
According to an embodiment, the inorganic nanoparticle may include tungsten (W), nickel (Ni), molybdenum (Mo), magnesium (Mg), chromium (Cr), bismuth (Bi), copper (Cu), niobium (Nb), barium (Ba), tin (Sn), zinc (Zn), strontium (Sr), titanium (Ti), or any combination thereof.
According to an embodiment, the inorganic nanoparticle may include WO2, WO3, NiO, MoO3, Cr2O3, Bi2O3, CuO, Cu2O, CuI, CuSCN, Nb2O5, BaSnO3, ZnO, ZnMgO, Zn2SnO4, SrTiO3, Zn2TiO8, or any combination thereof.
According to an embodiment, the inorganic nanoparticle may include a quantum dot.
According to an embodiment, the quantum dot may have a core-shell structure including a core including a semiconductor compound; and
According to an embodiment, the semiconductor compound 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 any combination thereof, and
the oxide material may include SiO2, Al2O3, TiO2, ZnO, MnO, Mn2O3, Mn3O4, CuO, FeO, Fe2O3, Fe3O4, CoO, Co3O4, NiO, MgAl2O4, CoFe2O4, NiFe2O4, CoMn2O4, or any combination thereof.
According to an embodiment, the semiconductor compound may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InNP, InAlP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, InZnP, InGaZnP, InAlZnP, GaS, GaSe, Ga2Se3, GaTe, InS, InSe, In2S3, In2Se3, InTe, InGaS3, InGaSe3, AgInS, AgInS2, CuInS, CuInS2, CuGaO2, AgGaO2, AgAlO2, SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, SnPbSTe, Si, Ge, SiC, SiGe, or any combination thereof.
According to an embodiment, the semiconductor compound in the shell may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, or any combination thereof.
Embodiments provide an ink composition for a light-emitting device which may include the inorganic nanoparticle-complex.
According to an embodiment, the ink composition may have a viscosity in a range of about 5 cP to about 80 cP at a temperature of about 25° C.
Embodiments provide a light-emitting device which may include a first electrode, a second electrode facing the first electrode, and an interlayer between the first electrode and the second electrode,
According to an embodiment, the inorganic nanoparticle-composites of the emission layer and/or the electron transport layer may be cross-linked and linked to each other.
According to an embodiment, the interlayer may further include:
Embodiments provide an electronic apparatus which may include the light-emitting device.
It is to be understood that the embodiments above are described in a generic and explanatory sense only and not for the purposes of limitation, and the disclosure is not limited to the embodiments described above.
The above and other aspects, and features, and advantages of the disclosure will be more apparent by describing in detail embodiments thereof with reference to the accompanying drawings, in which:
The disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments are shown. This disclosure may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.
In the drawings, the sizes, thicknesses, ratios, and dimensions of the elements may be exaggerated for ease of description and for clarity. Like reference numbers and/or like reference characters refer to like elements throughout.
In the description, it will be understood that when an element (or region, layer, part, etc.) is referred to as being “on”, “connected to”, or “coupled to” another element, it can be directly on, connected to, or coupled to the other element, or one or more intervening elements may be present therebetween. In a similar sense, when an element (or region, layer, part, etc.) is described as “covering” another element, it can directly cover the other element, or one or more intervening elements may be present therebetween.
In the description, when an element is “directly on,” “directly connected to,” or “directly coupled to” another element, there are no intervening elements present. For example, “directly on” may mean that two layers or two elements are disposed without an additional element such as an adhesion element therebetween.
It will be understood that the terms “connected to” or “coupled to” may refer to a physical, electrical and/or fluid connection or coupling, with or without intervening elements.
As used herein, the expressions used in the singular such as “a,” “an,” and “the,” are intended to include the plural forms as well, unless the context clearly indicates otherwise.
As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. For example, “A and/or B” may be understood to mean “A, B, or A and B.” The terms “and” and “or” may be used in the conjunctive or disjunctive sense and may be understood to be equivalent to “and/or”.
In the specification and the claims, the term “at least one of” is intended to include the meaning of “at least one selected from the group of” for the purpose of its meaning and interpretation. For example, “at least one of A and B” may be understood to mean “A, B, or A and B.” When preceding a list of elements, the term, “at least one of,” modifies the entire list of elements and does not modify the individual elements of the list.
It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. Thus, a first element could be termed a second element without departing from the teachings of the disclosure. Similarly, a second element could be termed a first element, without departing from the scope of the disclosure.
The spatially relative terms “below”, “beneath”, “lower”, “above”, “upper”, or the like, may be used herein for ease of description to describe the relations between one element or component and another element or component as illustrated in the drawings. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the drawings. For example, in the case where a device illustrated in the drawing is turned over, the device positioned “below” or “beneath” another device may be placed “above” another device. Accordingly, the illustrative term “below” may include both the lower and upper positions. The device may also be oriented in other directions and thus the spatially relative terms may be interpreted differently depending on the orientations.
The terms “about” or “approximately” as used herein is inclusive of the stated value and means within an acceptable range of deviation for the recited value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with measurement of the recited quantity (i.e., the limitations of the measurement system). For example, “about” may mean within one or more standard deviations, or within +20%, 10%, or ±5% of the stated value.
It should be understood that the terms “comprises,” “comprising,” “includes,” “including,” “have,” “having,” “contains,” “containing,” and the like are intended to specify the presence of stated features, integers, steps, operations, elements, components, or combinations thereof in the disclosure, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.
Unless otherwise defined or implied herein, all terms (including technical and scientific terms) used have the same meaning as commonly understood by those skilled in the art to which this disclosure pertains. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and should not be interpreted in an ideal or excessively formal sense unless clearly defined in the specification.
Upon performing a baking process by modifying the surface of an existing ligand, such as oleic acid, with a thermally cured ligand capable of cross linking, the stacking density of a quantum dot layer was increased and the voids were reduced by reducing the particle-to-particle distance through cross linking between quantum dots. Accordingly, the charge leakage characteristics were improved, and additionally, the range of selection for ink compositions of an upper layer could be widened.
A ligand compound according to an embodiment may be represented by Formula 1:
In Formula 1,
deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or a nitro group;
The ligand compound of Formula 1 may be coordinately bonded to the inorganic nanoparticle through the thiol group, the carboxy group, or the alkoxysilane group at the terminal end of R2.
Since the ligand compound of Formula 1 has a benzophenone moiety, photocuring may be performed thereon. Therefore, when a layer including the inorganic nanoparticle coordinated with the ligand compound of Formula 1 according to an embodiment is photocured, the packing density of the layer may be improved and the stability of the layer may be increased. Accordingly, the efficiency of a light-emitting device including the layer may increase.
In an embodiment, in Formula 1, a length of R2 may be greater than a length of R3. When a length of R3 is greater than a length of R2, the crosslinking reaction may not occur smoothly because the distance between neighboring benzophenones increases.
In an embodiment, in Formula 1, a length of R2 may be greater than a length of R1. When a length of R1 is greater than a length of R2, the distance between ligands may be increased so that the distance between neighboring benzophenones may be also increased, and accordingly, a crosslinking reaction may not occur smoothly. R1 may also serve to control dispersion in a solvent, and thus dispersion may be controlled by adjusting R1.
In an embodiment, in Formula 1, a length of R1 may be greater than a length of R3. In an embodiment, R3 may be hydrogen or deuterium, and R1 may be a C1-C20 alkyl group or a C6-C30 aryl group.
In an embodiment, the alkoxysilane group may be —Si(Q1)(Q2)(Q3), and Q1 to Q3 may each independently be a C1-C60 alkoxy group. For example, the alkoxysilane group may be —Si(OCH3)3 or —Si(OCH2CH3)3.
In an embodiment, the ligand compound represented by Formula 1 may be one of Compounds 1 to 8:
An inorganic nanoparticle-composite according to another embodiment may include:
In an embodiment, the inorganic nanoparticle may include tungsten (W), nickel (Ni), molybdenum (Mo), magnesium (Mg), chromium (Cr), bismuth (Bi), copper (Cu), niobium (Nb), barium (Ba), tin (Sn), zinc (Zn), strontium (Sr), titanium (Ti), or any combination thereof.
In an embodiment, the inorganic nanoparticle may include WO2, WO3, NiO, MoO3, Cr2O3, Bi2O3, CuO, Cu2O, CuI, CuSCN, Nb2O5, BaSnO3, ZnO, ZnMgO, Zn2SnO4, SrTiO3, Zn2TiO8, or any combination thereof.
In an embodiment, the inorganic nanoparticle may include a quantum dot.
In an embodiment, the quantum dot may have a core-shell structure including: a core including a semiconductor compound; and a shell including an oxide material, a semiconductor compound, or any combination thereof, and the oxide material may include a metal oxide, a metalloid oxide, a non-metal oxide, or any combination thereof.
More details of the quantum dot will be described later.
An ink composition for a light-emitting device according to another embodiment may include the inorganic nanoparticle-composite.
In an embodiment, the ink composition may have a viscosity in a range of about 5 cP to about 80 cP at a temperature of about 25° C. When the viscosity of the ink composition is within the range above, the ink composition may be suitable for a solution process (e.g., an inkjet process). A solvent included in the ink composition for the light-emitting device may be, for example, a compound such as an alcohol or an ether. The ink composition for the light-emitting device may further include, for example, a dispersant as needed. The dispersant may include general anionic, cationic, and/or nonionic polymeric materials.
A light-emitting device according to another embodiment may include: a first electrode; a second electrode facing the first electrode; and an interlayer between the first electrode and the second electrode, wherein
For example, the emission layer and/or the electron transport layer may each be a layer formed only of the ink composition.
An electronic apparatus according to another embodiment may include the light-emitting device.
In an embodiment, the electronic apparatus may further include a thin-film transistor,
In an embodiment, the electronic apparatus may further include a color filter, a color conversion layer, a touch screen layer, a polarizing layer, or any combination thereof.
In an embodiment, a capping layer may be arranged outside the first electrode and/or the second electrode.
The term “interlayer” as used herein refers to a single layer and/or all layers between the first electrode and the second electrode of the light-emitting device.
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 any combination thereof. In embodiments, when the first electrode 110 is a semi-transmissive electrode or a reflective electrode, a material for forming the first electrode 110 may include magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), or any combination thereof.
The first electrode 110 may have a structure consisting of a single layer or a structure including multiple layers. For example, the first electrode 110 may have a three-layer structure of ITO/Ag/ITO.
The interlayer 130 may be arranged 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.
In an embodiment, the interlayer 130 may further include, in addition to various organic materials, a metal-containing compound such as an organometallic compound, an inorganic material such as a quantum dot, and the like.
The interlayer 130 may include two or more emitting units stacked between the first electrode 110 and the second electrode 150, and at least one charge generation layer between the two or more emitting units. When the emission layer 130 includes the two or more emitting units and the at least one charge generation layer, the light-emitting device 10 may be a tandem light-emitting device.
The hole transport region may have a structure consisting of a layer consisting of a single material, a structure consisting of a layer including different materials, or a structure including multiple layers including different materials.
The hole transport region 120 may include a hole injection layer, a hole transport layer, an emission auxiliary layer, an electron blocking layer, or any combination thereof.
For example, the hole transport region 120 may have a multi-layer 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 may be stacked from the first electrode 110 in its respective stated order, but the structure of the hole transport region is not limited thereto.
The hole transport region 120 may include a compound represented by Formula 201, a compound represented by Formula 202, or any combination thereof:
In Formulae 201 and 202,
In an embodiment, the compound represented by Formula 201 and the compound represented by Formula 202 may each independently include at least one of groups represented by Formulae CY201 to CY217:
In Formulae CY201 to CY217, R10b and R10c may each independently be the same as defined in connection with R10a, ring CY201 to ring CY204 may each independently be a C3-C20 carbocyclic group or a C1-C20 heterocyclic group, and at least one hydrogen in Formulae CY201 to CY217 may be unsubstituted or substituted with R10a.
In an embodiment, ring CY201 to ring CY204 in Formulae CY201 to CY217 may each independently be a benzene group, a naphthalene group, a phenanthrene group, or an anthracene group.
In embodiments, the compound represented by Formula 201 and the compound represented by Formula 202 may include at least one of groups represented by Formulae CY201 to CY203.
In embodiments, the compound represented by Formula 201 may include at least one of groups represented by Formulae CY201 to CY203 and at least one of groups represented by Formulae CY204 to CY217.
In embodiments, in Formula 201, xa1 may be 1, R201 may be one of groups represented by Formulae CY201 to CY203, xa2 may be 0, and R202 may be one of groups represented by Formulae CY204 to CY207.
In embodiments, the compound represented by Formula 201 and the compound represented by Formula 202 may each not include groups represented by Formulae CY201 to CY203.
In embodiments, the compound represented by Formula 201 and the compound represented by Formula 202 may each not include groups represented by Formulae CY201 to CY203, and may each independently include at least one of groups represented by Formulae CY204 to CY217.
In embodiments, the compound represented by Formula 201 and the compound represented by Formula 202 may each not include groups represented by Formulae CY201 to CY217.
For example, the hole transport region may include one of 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:
A thickness of the hole transport region may be in a range of about 50 Å to about 10,000 Å. For example, the thickness of the hole transport region may be in a range of about 100 Å to about 4,000 Å. When the hole transport region includes a hole injection layer, a hole transport layer, or any combination thereof, a thickness of the hole injection layer may be in a range of about 100 Å to about 9,000 Å, and a thickness of the hole transport layer may be in a range of about 50 Å to about 2,000 Å. For example, the thickness of the hole injection region may be in a range of about 100 Å to about 1,000 Å. For example, the thickness of the hole transport layer may be in a range of 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 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 a wavelength of light emitted by the emission layer, and the electron blocking layer may block the leakage of electrons from the emission layer to the hole transport region. Materials that may be included in the hole transport region may be included in the emission auxiliary layer and the electron blocking layer.
[p-Dopant]
The hole transport region may further include, in addition to these materials, a charge-generation material for the improvement of conductive properties. The charge-generation material may be uniformly or non-uniformly dispersed in the hole transport region (for example, in the form of a single layer consisting of a charge-generation material).
The charge-generation material may be, for example, a p-dopant.
For example, the p-dopant may have a lowest unoccupied molecular orbital (LUMO) energy level of less than or equal to about −3.5 eV.
In an embodiment, the p-dopant may include a quinone derivative, a cyano group-containing compound, a compound including element EL1 and element EL2, or any combination thereof.
Examples of a quinone derivative may include TCNQ, F4-TCNQ, and the like.
Examples of a cyano group-containing compound may include HAT-CN, a compound represented by Formula 221, and the like.
In Formula 221,
In the compound including element EL1 and element EL2, element EL1 may be a metal, a metalloid, or any combination thereof, and element EL2 may be a non-metal, a metalloid, or any combination thereof.
Examples of a 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.); 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.); and the like.
Examples of a metalloid may include silicon (Si), antimony (Sb), tellurium (Te), and the like.
Examples of a non-metal may include oxygen (O), a halogen (for example, F, Cl, Br, I, etc.), and the like.
Examples of the compound including element EL1 and element EL2 may include a metal oxide, a metal halide (for example, a metal fluoride, a metal chloride, a metal bromide, 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 a 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.), a rhenium oxide (for example, ReO3, etc.), and the like.
Examples of ae metal halide may include an alkali metal halide, an alkaline earth metal halide, a transition metal halide, a post-transition metal halide, a lanthanide metal halide, and the like.
Examples of an alkali metal halide may include LiF, NaF, KF, RbF, CsF, LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI, RbI, CsI, and the like.
Examples of an alkaline earth metal halide may include BeF2, MgF2, CaF2, SrF2, BaF2, BeCl2, MgCl2, CaCl2), SrCl2, BaCl2, BeBr2, MgBr2, CaBr2, SrBr2, BaBr2, Bel2, Mg12, CaI2, SrI2, BaI2, and the like.
Examples of a transition metal halide may include a titanium halide (for example, TiF4, TiCl4, TiBr4, TiI4, etc.), a zirconium halide (for example, ZrF4, ZrCl4, ZrBr4, ZrI4, etc.), a hafnium halide (for example, HfF4, HfCl4, HfBr4, Hfl4, etc.), a vanadium halide (for example, VF3, VCl3, VBr3, VI3, etc.), a niobium halide (for example, NbF3, NbCl3, NbBr3, NbI3, etc.), a tantalum halide (for example, TaF3, TaCl3, TaBr3, TaI3, etc.), a chromium halide (for example, CrF3, CrCl3, CrBr3, CrI3, etc.), a molybdenum halide (for example, MoF3, MoCl3, MoBr3, MoI3, etc.), a tungsten halide (for example, WF3, WCl3, WBr3, WI3, etc.), a manganese halide (for example, MnF2, MnCl2, MnBr2, MnI2, etc.), a technetium halide (for example, TcF2, TcCl2, TcBr2, TcI2, etc.), a rhenium halide (for example, ReF2, ReCl2, ReBr2, ReI2, etc.), an iron halide (for example, FeF2, FeCl2, FeBr2, 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, COC12, CoBr2, CoI2, etc.), a rhodium halide (for example, RhF2, RhCl2, RhBr2, Rhl2, etc.), an iridium halide (for example, IrF2, IrCl2, IrBr2, Ir12, 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.), a gold halide (for example, AuF, AuCl, AuBr, AuI, etc.), and the like.
Examples of a post-transition metal halide may include a zinc halide (for example, ZnF2, ZnCl2, ZnBr2, ZnI2, etc.), an indium halide (for example, InI3, etc.), a tin halide (for example, SnI2, etc.), and the like.
Examples of a lanthanide metal halide may include YbF, YbF2, YbF3, SmF3, YbCl, YbCl2, YbCl3 SmCl3, YbBr, YbBr2, YbBr3 SmBr3, YbI, YbI2, YbI3, SmI3, and the like.
Examples of a metalloid halide may include antimony halide (for example, SbCl5, etc.) and the like.
Examples of a metal telluride may include an alkali metal telluride (for example, Li2Te, a 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.), a lanthanide metal telluride (for example, LaTe, CeTe, PrTe, NdTe, PmTe, EuTe, GdTe, TbTe, DyTe, HoTe, ErTe, TmTe, YbTe, LuTe, etc.), and 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 subpixel. 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 may contact each other or are may be separated from each other to emit white light. In embodiments, the emission layer may include two or more materials of a red light-emitting material, a green light-emitting material, and a blue light-emitting material, in which the two or more materials may be mixed with each other in a single layer to emit white light.
The emission layer may include a quantum dot.
A thickness of the emission layer may be in a range of about 100 Å to about 1,000 Å. For example, the thickness of the emission layer may be in a range of about 200 Å to about 600 Å. When the thickness of the emission layer is within these ranges, excellent luminescence characteristics may be obtained without a substantial increase in driving voltage.
In the specification, a “quantum dot” may be a crystal of a semiconductor compound, and may include any material capable of emitting light of various emission wavelengths according to a size of the crystal. By adjusting an element ratio in a quantum dot compound, quantum dots may emit light of various emission wavelengths.
A diameter of the quantum dot 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 process, a molecular beam epitaxy process, or any process similar thereto.
The wet chemical process is a method that includes mixing a precursor material with an organic solvent and growing quantum dot particle crystals. 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 may be controlled through a process which costs less, and may be more readily performed than vapor deposition methods, such as metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE).
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 any combination thereof.
Examples of a Group II-VI semiconductor compound may include: a binary compound, such as CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS, and the like; a ternary compound, such as CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, and the like; a quaternary compound, such as CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, and the like; or any combination thereof.
Examples of a Group III-V semiconductor compound may include: 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; or any combination thereof. In an embodiment, the Group III-V semiconductor compound may further include a Group II element. Examples of a Group III-V semiconductor compound further including a Group II element may include InZnP, InGaZnP, InAlZnP, and the like.
Examples of a Group III-VI semiconductor compound may include: a binary compound, such as GaS, GaSe, Ga2Se3, GaTe, InS, InSe, In2S3, In2Se3, InTe, and the like; a ternary compound, such as InGaS3, InGaSe3, and the like; or any combination thereof.
Examples of a Group I-III-VI semiconductor compound may include: a ternary compound, such as AgInS, AgInS2, CuInS, CuInS2, CuGaO2, AgGaO2, AgAlO2, and the like; or any combination thereof.
Examples of a Group IV-VI semiconductor compound may include: a binary compound, such as SnS, SnSe, SnTe, PbS, PbSe, PbTe, and the like; a ternary compound, such as SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and the like; a quaternary compound, such as SnPbSSe, SnPbSeTe, SnPbSTe, and the like; or any combination thereof.
Examples of a Group IV element or compound may include: a single element material, such as Si, Ge, and the like; a binary compound, such as SiC, SiGe, and the like; or any combination thereof.
Each element included in a multi-element compound, such as a binary compound, a ternary compound, and a quaternary compound, may be present at a uniform concentration or at a non-uniform concentration in a particle.
In an embodiment, the quantum dot may have a single structure in which the concentration of each element in the quantum dot is uniform, or the quantum dot may have a core-shell structure. For example, a material included in the core and a material included in the shell may be different from each other.
The shell of the quantum dot may serve as a protective layer which prevents chemical denaturation of the core to maintain semiconductor characteristics, and/or may serve as a charging layer which imparts electrophoretic characteristics to the quantum dot. The shell may be single-layered or multi-layered. An interface between the core and the shell may have a concentration gradient in which the concentration of a material present in the shell decreases toward the core.
Examples of a material forming the shell of the quantum dot may include an oxide material, a semiconductor compound, or any combination thereof. An oxide material may include a metal oxide, a metalloid oxide, a non-metal oxide, or any combination thereof. Examples of the oxide material (for example a metal oxide, a metalloid oxide, and/or a non-metal oxide) may include: a binary compound, such as SiO2, Al2O3, TiO2, ZnO, MnO, Mn2O3, Mn3O4, CuO, FeO, Fe2O3, Fe3O4, CoO, Co3O4, NiO, and the like; a ternary compound, such as MgAl2O4, CoFe2O4, NiFe2O4, CoMn2O4, and the like; or any combination thereof.
Examples of the semiconductor compound, as described herein, 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; or any combination thereof. Examples of the semiconductor compound may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, or any combination thereof.
The quantum dot may have a full width at half maximum (FWHM) of an emission wavelength spectrum less than or equal to about 45 nm. For example, a FWHM of an emission wavelength spectrum of the quantum dot may be less than or equal to about 40 nm. For example, a FWHM of an emission wavelength spectrum of the quantum dot may be less than or equal to about 30 nm. When the FWHM of the quantum dot is within these ranges, the quantum dot may have improved color purity or improved color reproducibility. Light emitted through the quantum dot may be emitted in all directions, so that a wide viewing angle may be improved.
In an embodiment, the quantum dot may be in a spherical form, a pyramidal form, a multi-arm form, or a cubic form, or the quantum dot may be in the shape of nanoparticles, nanotubes, nanowires, nanofibers, or nanoplate particles.
Since the energy band gap may be adjusted by controlling the size of the quantum dot, light having various wavelength bands may be obtained from the quantum dot emission layer. Accordingly, by using quantum dots of different sizes, a light-emitting device that emits light of various wavelengths may be implemented. In an embodiment, the size of the quantum dots may be selected to emit red light, green light, and/or blue light. The size of the quantum dots may be configured to emit white light by combination of light of various colors.
In an embodiment, the emission layer may include:
For example, the quantum dot may be coordinated with the ligand compound represented by Formula 1 according to an embodiment. The emission layer formed of the ink composition for the light emitting device including the inorganic nanoparticle-composite may be cross-linked so that the quantum dots of the emission layer may be connected to each other. Accordingly, the film density of the emission layer may be improved and the film damage between processes may be reduced.
The electron transport region may have a structure consisting of a layer consisting of a single material, a structure consisting of a layer including different materials, or a structure including multiple layers including different materials.
The electron transport region may include an electron transport layer; a hole blocking layer, an electron injection layer, or any combination thereof.
In an embodiment, the electron transport region (for example, the hole blocking 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:
In Formula 601,
In an embodiment, in Formula 601, when xe11 is 2 or more, two or more of Ar601 may be linked to each other via a single bond.
In an embodiment, in Formula 601, Ar601 may be a substituted or unsubstituted anthracene group.
In embodiments, the electron transport region may include a compound represented by Formula 601-1:
In Formula 601-1,
In an embodiment, in Formulae 601 and 601-1, xe1 and xe611 to xe613 may each independently be 0, 1, or 2.
The electron transport region may include one of Compounds ET1 to ET45, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), Alq3, BAlq, TAZ, NTAZ, or any combination thereof:
In an embodiment, the electron transport layer may include the inorganic nanoparticle-composite including: an inorganic nanoparticle; and the ligand compound, wherein the ligand compound may be coordinately bonded to the inorganic nanoparticle.
In an embodiment, the inorganic nanoparticle may include W, Ni, Mo, Mg, Cr, Bi, Cu, Nb, Ba, Sn, Zn, Sr, Ti, or any combination thereof. In an embodiment, the inorganic nanoparticle may include WO2, WO3, NiO, MoO3, Cr2O3, Bi2O3, CuO, Cu2O, CuI, CuSCN, Nb2O5, BaSnO3, ZnO, ZnMgO, Zn2SnO4, SrTiO3, Zn2TiO8, or any combination thereof.
For example, the inorganic nanoparticle may be coordinated with the ligand compound represented by Formula 1 according to an embodiment. The electron transport layer formed of the ink composition for the light-emitting device including the inorganic nanoparticle-composite may be cross-linked so that the inorganic nanoparticle-composites of the electron transport layer may be connected to each other. Accordingly, the film density of the electron transport layer may be improved and the film damage between processes may be reduced.
When both the emission layer and the electron transport layer are layers formed of the ink composition for the light-emitting device and these two layers are in direct contact, the emission layer and the electron transport layer may be connected to each other via a chemical bond. Accordingly, void defects that may occur in the stacked structure may be reduced, thereby preventing leakage current that does not contribute to light emission. As a result, degradation of the efficiency of the light-emitting device may be prevented.
Due to increased adhesion between layers, the stability against external energy and physical stress generated during device operation increases, becoming advantageous for manufacturing flexible devices such as flexible and rollable devices.
Furthermore, since crosslinking of an interlayer mixing may be prevented and the range of selecting a solvent for the ink composition is wide, controlling the physical properties of the ink to improve an inkjet printing process may be advantageous.
A thickness of the electron transport region may be in a range of about 100 Å to about 5,000 Å. For example, the thickness of the electron transport region may be in a range of about 160 Å to about 4,000 Å. When the electron transport region includes the hole blocking layer, the electron transport layer, or any combination thereof, a thickness of the hole blocking layer or a thickness of the electron transport layer may be in a range of about 20 Å to about 1,000 Å, and a thickness of the electron transport layer may be from about 100 Å to about 1,000 Å. For example, the thickness of the buffer layer, the hole blocking layer, or the electron control layer may each independently be in a range of about 30 Å to about 300 Å. For example, the thickness of the electron transport layer may be in a range of 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, satisfactory electron transporting characteristics may be obtained without a substantial increase in driving voltage.
The electron transport region may include, in addition to the aforementioned materials, a metal-containing material.
The metal-containing material may include an alkali metal complex, an alkaline earth metal complex, or any combination thereof. A metal ion of the alkali metal complex may be a Li ion, a Na ion, a K ion, a Rb ion, or a Cs ion, and a metal ion of the alkaline earth metal complex may be a Be ion, a Mg ion, a Ca ion, a Sr ion, or a Ba ion.
A ligand coordinated with the metal ion of the alkali metal complex or with the metal ion of 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) or Compound ET-D2:
The electron transport region may include an electron injection layer that facilitates the injection of electrons from the second electrode 150. The electron injection layer may contact (e.g., directly contact) the second electrode 150.
The electron injection layer may have a structure consisting of a layer consisting of a single material, a structure consisting of a layer including different materials, or a structure including multiple layers including different materials.
The electron injection layer may include an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal-containing compound, an alkaline earth metal-containing compound, a rare earth metal-containing compound, an alkali metal complex, an alkaline earth metal complex, a rare earth metal complex, or any combination thereof.
The alkali metal may include Li, Na, K, Rb, Cs, or any combination thereof. The alkaline earth metal may include Mg, Ca, Sr, Ba, or any combination thereof. The rare earth metal may include Sc, Y, Ce, Tb, Yb, Gd, or any combination thereof.
The alkali metal-containing compound, the alkaline earth metal-containing compound, and the rare earth metal-containing compound may include oxides, halides (for example, fluorides, chlorides, bromides, iodides, etc.), or tellurides of the alkali metal, the alkaline earth metal, and the rare earth metal, or any combination thereof.
The alkali metal-containing compound may include: an alkali metal oxide, such as Li2O, Cs2O, K2O, and the like; alkali metal halides, such as LiF, NaF, CsF, KF, LiI, NaI, CsI, KI, and the like; or any combination thereof. The alkaline earth metal-containing compound may include an alkaline earth metal compound, such as BaO, SrO, CaO, BaxSr1-xO (wherein x is a real number satisfying 0<x<1), BaxCa1-xO (wherein x is a real number satisfying 0<x<1), and the like. The rare earth metal-containing compound may include YbF3, ScF3, Sc2O3, Y2O3, Ce2O3, GdF3, TbF3, YbI3, ScI3, TbI3, or any combination thereof. In an embodiment, the rare earth metal-containing compound may include a lanthanide metal telluride. Examples of the lanthanide metal telluride may include LaTe, CeTe, PrTe, NdTe, PmTe, SmTe, EuTe, GdTe, TbTe, DyTe, HoTe, ErTe, TmTe, YbTe, LuTe, La2Te3, Ce2Te3, Pr2Te3, Nd2Te3, Pm2Te3, Sm2Te3, Eu2Te3, Gd2Te3, Tb2Te3, Dy2Te3, Ho2Te3, Er2Te3, Tm2Te3, Yb2Te3, Lu2Te3, and the like.
The alkali metal complex, the alkaline earth-metal complex, and the rare earth metal complex may include an alkali metal ion, an alkaline earth metal ion, or a rare earth metal ion and 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.
In an embodiment, the electron injection layer may consist of an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal-containing compound, an alkaline earth metal-containing compound, a rare earth metal-containing compound, an alkali metal complex, an alkaline earth metal complex, a rare earth metal complex, or any combination thereof, as described above. In embodiments, the electron injection layer may further include an organic material (for example, a compound represented by Formula 601).
In an embodiment, the electron injection layer may consist of an alkali metal-containing compound (for example, alkali metal halide), or the electron injection layer may consist of an alkali metal-containing compound (for example, alkali metal halide), and an alkali metal, an alkaline earth metal, a rare earth metal, or any combination thereof. For example, the electron injection layer may be a KI:Yb co-deposited layer, an RbI:Yb co-deposited layer, a LiF:Yb co-deposited layer, and the like.
When the electron injection layer further includes an organic material, an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal-containing compound, an alkaline earth metal-containing compound, a rare earth metal-containing compound, an alkali metal complex, an alkaline earth-metal complex, a rare earth metal complex, or any combination thereof may be uniformly or non-uniformly dispersed in a matrix including the organic material.
A thickness of the electron injection layer may be in a range of about 1 Å to about 100 Å. For example, the thickness of the electron injection layer may be in a range of about 3 Å to about 90 Å. When the thickness of the electron injection layer is within the ranges described above, satisfactory electron injection characteristics may be obtained without a substantial increase in driving voltage.
The second electrode 150 is arranged on the aforementioned interlayer 130. The second electrode 150 may be a cathode, which is an electron injection electrode. The second electrode 150 may include a material having a low-work function, for example, a metal, an alloy, an electrically conductive compound, or any combination thereof.
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 multi-layered structure.
The light-emitting device 10 may include a first capping layer outside the first electrode 110, and/or a second capping layer outside the second electrode 150. For example, the light-emitting device 10 may have a structure in which the first capping layer, the first electrode 110, the interlayer 130, and the second electrode 150 are stacked in the stated order, a structure in which the first electrode 110, the interlayer 130, the second electrode 150, and the second capping layer are stacked in 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 stacked in the stated order.
For example, the light generated by the emission layer in the interlayer 130 of the light-emitting device 10 may be extracted to the outside through the second electrode 150, which may be a semi-transmissive electrode or a transmissive electrode, and through the second capping layer.
The first capping layer and the second capping layer may each increase external emission efficiency according to the principle of constructive interference. Accordingly, the light extraction efficiency of the light-emitting device 10 may be increased, so that the luminescence efficiency of the light-emitting device 10 may be improved.
The first capping layer and the second capping layer may each include a material having a refractive index of greater than or equal to about 1.6 (with respect to a wavelength at about 589 nm).
The first capping layer and the second capping layer may each independently be an organic capping layer including an organic material, an inorganic capping layer including an inorganic material, or a composite capping layer including an organic material and an inorganic material.
At least one of the first capping layer and the second capping layer may each independently include a carbocyclic compound, a heterocyclic compound, an amine group-containing compound, a porphine derivative, a phthalocyanine derivative, a naphthalocyanine derivative, an alkali metal complex, an alkaline earth metal complex, or any combination thereof. The carbocyclic compound, the heterocyclic compound, and the amine group-containing compound may each optionally be substituted with a substituent including O, N, S, Se, Si, F, Cl, Br, I, or any combination thereof.
In an embodiment, at least one of the first capping layer and the second capping layer may each independently include an amine group-containing compound.
In embodiments, at least one of the first capping layer and the second capping layer may each independently include a compound represented by Formula 201, a compound represented by Formula 202, or any combination thereof.
In embodiments, at least one of the first capping layer and the second capping layer may each independently include: one of Compounds HT28 to HT33; one of Compounds CP1 to CP6; β-NPB; or any combination thereof:
The light-emitting device may be included in various electronic apparatuses. For example, the electronic apparatus including the light-emitting device may be a light-emitting apparatus, an authentication apparatus, and the like.
The electronic apparatus (for example, a light-emitting apparatus) may further include, in addition to the light-emitting device, a color filter, a color conversion layer, or a color filter and a color conversion layer. The color filter and/or the color conversion layer may be arranged in at least one traveling direction of light emitted from the light-emitting device. In an embodiment, the light emitted from the light-emitting device may be blue light or white light. The light-emitting device may be the same as described herein. In an embodiment, the color conversion layer may include a quantum dot. The quantum dot may be, for example, the quantum dot as described herein.
The electronic apparatus may include a first substrate. The first substrate may include subpixels, the color filter may include color filter areas respectively corresponding to the subpixels, and the color conversion layer may include color conversion areas respectively corresponding to the subpixels.
A pixel-defining film may be arranged between the subpixels to define each subpixel.
The color filter may further include color filter areas and light-shielding patterns arranged between the color filter areas, and the color conversion layer may further include color conversion areas and light-shielding patterns arranged between the color conversion areas.
The color filter areas (or the color conversion areas) may include a first area emitting first color light, a second area emitting second color light, and/or a third area emitting third color light, wherein the first color light, the second color light, and/or the third color light may have different maximum emission wavelengths from one another. For example, the first color light may be red light, the second color light may be green light, and the third color light may be blue light. For example, the color filter areas (or the color conversion areas) may include quantum dots. For example, the first area may include a red quantum dot, the second area may include a green quantum dot, and the third area may not include a quantum dot. The quantum dot may be the same as described herein. The first area, the second area, and/or the third area may each further include a scatterer.
For example, the light-emitting device may emit first light, the first area may absorb the first light to emit a first-first color light, the second area may absorb the first light to emit a second-first color light, and the third area may absorb the first light to emit a third-first color light. The first-first color light, the second-first color light, and the third-first color light may each have different maximum emission wavelengths from one another. For example, 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 active layer, wherein any one of the source electrode and the drain electrode may be electrically connected to any one of the first electrode and the second electrode of the light-emitting device 10.
The thin-film transistor may further include a gate electrode, a gate insulating film, and the like.
The active layer may include crystalline silicon, amorphous silicon, an organic semiconductor, an oxide semiconductor, and the like.
The electronic apparatus may further include a sealing portion for sealing the light-emitting device. The sealing portion may be arranged 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 prevents ambient air and moisture from penetrating into the light-emitting device. The sealing portion may be a sealing substrate including a transparent glass substrate or a plastic substrate. The sealing portion may be a thin-film encapsulation layer including an organic layer and/or an inorganic layer. When the sealing portion is a thin film encapsulation layer, the electronic apparatus may be flexible.
Various functional layers may be additionally arranged on the sealing portion, in addition to the color filter and/or the color conversion layer, according to the use of the electronic apparatus. Examples of the functional layers may include a touch screen layer, a polarizing layer, and the like. The touch screen layer may be a pressure-sensitive touch screen layer, a capacitive touch screen layer, or an infrared touch screen layer.
The authentication apparatus may be, for example, a biometric authentication apparatus that authenticates an individual by using biometric information of a living body (for example, fingertips, pupils, etc.).
The authentication apparatus may further include, in addition to the light-emitting device as described above, a biometric information collector.
The electronic apparatus may be applied to various displays, light sources, lighting, personal computers (for example, a mobile personal computer), mobile phones, digital cameras, electronic organizers, electronic dictionaries, electronic game machines, medical instruments (for example, electronic thermometers, sphygmomanometers, blood glucose meters, pulse measurement devices, pulse wave measurement devices, electrocardiogram displays, ultrasonic diagnostic devices, or endoscope displays), fish finders, various measuring instruments, meters (for example, meters for a vehicle, an aircraft, and a vessel), projectors, and the like.
The electronic apparatus of
The substrate 100 may be a flexible substrate, a glass substrate, or a metal substrate. A buffer layer 210 may be arranged on the substrate 100. The buffer layer 210 may prevent penetration of impurities through the substrate 100 and may provide a flat surface on the substrate 100.
A TFT may be arranged on the buffer layer 210. The TFT may include an active layer 220, a gate electrode 240, a source electrode 260, and a drain electrode 270.
The active 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 active layer 220 from the gate electrode 240 may be arranged on the active layer 220, and the gate electrode 240 may be arranged on the gate insulating film 230.
An interlayer insulating film 250 may be arranged on the gate electrode 240. The interlayer insulating film 250 may be arranged between the gate electrode 240 and the source electrode 260 to insulate the gate electrode 240 from the source electrode 260 and between the gate electrode 240 and the drain electrode 270, to insulate the gate electrode 240 from the drain electrode 270.
The source electrode 260 and the drain electrode 270 may be arranged on the interlayer insulating film 250. The interlayer insulating film 250 and the gate insulating film 230 may be formed to expose a source region and a drain region of the active layer 220, and the source electrode 260 and the drain electrode 270 may respectively contact the exposed portions of the source region and the drain region of the active layer 220.
The TFT may be electrically connected to a light-emitting device 10 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. The 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 arranged on the passivation layer 280. The passivation layer 280 may be arranged to expose a portion of the drain electrode 270, and may not fully cover the drain electrode 270. The first electrode 110 may be electrically connected to the exposed portion of the drain electrode 270.
A pixel defining layer 290 including an insulating material may be arranged 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-based organic film or a polyacrylic-based organic film. Although not shown in
The second electrode 150 may be arranged on the interlayer 130, and a capping layer 170 may be further included on the second electrode 150. The capping layer 170 may be formed to cover the second electrode 150.
The encapsulation portion 300 may be arranged on the capping layer 170. The encapsulation portion 300 may be arranged on a light-emitting device to protect the light-emitting device from moisture or oxygen. The encapsulation portion 300 may include: an inorganic film including silicon nitride (SiNx), silicon oxide (SiOx), indium tin oxide, indium zinc oxide, or any combination thereof; an organic film including polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, polyethylene sulfonate, polyoxymethylene, polyarylate, hexamethyldisiloxane, an acrylic resin (for example, polymethyl methacrylate, polyacrylic acid, or the like), an epoxy-based resin (for example, aliphatic glycidyl ether (AGE), or the like), or any combination thereof; or any combination of the inorganic films and the organic films.
The electronic apparatus of
Respective layers included in the hole transport region, the emission layer, and respective layers included in the electron transport region may be formed in a selected region by using one or more suitable methods selected from vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) deposition, ink-jet printing, laser-printing, laser-induced thermal imaging, and the like. However, the emission layer and/or the electron transport layer may be formed using an inkjet. An inkjet printer or the like used for the inkjet may be an inkjet printer of the related art.
When each of the layers included in the hole transport region, the emission layer, and each of the layers included in the electron transport region are formed by vacuum deposition, the deposition may be performed at a deposition temperature of about 100° C. to about 500° C., a vacuum degree of about 10−8 torr to about 10−3 torr, and 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.
When each of the layers included in the hole transport region, the emission layer, and each of the layers included in the electron transport region are formed by spin coating, the spin coating may be performed at a coating speed of about 2,000 rpm to about 5,000 rpm and at a heat treatment temperature of about 80° C. to about 200° C. by taking into account a material to be included in a layer to be formed and the structure of a layer to be formed.
The term “C3-C60 carbocyclic group” as used herein may be a cyclic group consisting of carbon atoms as the only ring-forming atom and having three to sixty carbon atoms, and the term “C1-C60 heterocyclic group” as used herein may be a cyclic group that has one to sixty carbon atoms and further has, in addition to a carbon atom, at least one 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 number of ring-forming atoms of a C1-C60 heterocyclic group may be from 3 to 61.
The term “cyclic group” as used herein may be a C3-C60 carbocyclic group or a C1-C60 heterocyclic group.
The term “π electron-rich C3-C60 cyclic group” as used herein may be a cyclic group that has three to sixty carbon atoms and may not include *—N═*′ as a ring-forming moiety, and the term “π electron-deficient nitrogen-containing C1-C60 cyclic group” as used herein may be a heterocyclic group that has one to sixty carbon atoms and may include *—N═*′ as a ring-forming moiety.
In embodiments,
The terms “cyclic group”, “C3-C60 carbocyclic group:, “C1-C60 heterocyclic group”, “π electron-rich C3-C60 cyclic group”, or “π electron-deficient nitrogen-containing C1-C60 cyclic group” as used herein may each be a group condensed to any cyclic group, a monovalent group, or a polyvalent group (for example, a divalent group, a trivalent group, a tetravalent group, etc.) according to the structure of a formula for which the corresponding term is used. For example, a “benzene group” may be a benzo group, a phenyl group, a phenylene group, or the like, which may be readily understood by one of ordinary skill in the art according to the structure of a formula including the “benzene group.”
Examples of a monovalent C3-C60 carbocyclic group or a monovalent C1-C60 heterocyclic group may include a C3-C10 cycloalkyl group, a C1-C1 heterocycloalkyl group, a C3-C10 cycloalkenyl group, a C1-C1 heterocycloalkenyl group, a C6-C60 aryl group, a C1-C60 heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group. Examples of a divalent C3-C60 carbocyclic group or a divalent C1-C60 heterocyclic group may include a C3-C10 cycloalkylene group, a C1-C1 heterocycloalkylene group, a C3-C10 cycloalkenylene group, a C1-C1 heterocycloalkenylene group, a C6-C60 arylene group, a C1-C60 heteroarylene group, a divalent non-aromatic condensed polycyclic group, and a divalent non-aromatic condensed heteropolycyclic group.
The term “C1-C60 alkyl group” as used herein may be a linear or branched aliphatic hydrocarbon monovalent group that has 1 to 60 carbon atoms, and examples thereof may include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a tert-pentyl group, a neopentyl group, an isopentyl group, a sec-pentyl group, a 3-pentyl group, a sec-isopentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isooctyl group, a sec-octyl group, a tert-octyl group, an n-nonyl group, an isononyl group, a sec-nonyl group, a tert-nonyl group, an n-decyl group, an isodecyl group, a sec-decyl group, and a tert-decyl group. The term “C1-C60 alkylene group” as used herein may be a divalent group having a same structure as the C1-C60 alkyl group.
The term “C2-C60 alkenyl group” as used herein may be a monovalent hydrocarbon group having at least one carbon-carbon double bond in the middle or at a terminus of a C2-C60 alkyl group, and examples thereof may include an ethenyl group, a propenyl group, a butenyl group, and the like. The term “C2-C60 alkenylene group” as used herein may be a divalent group having a same structure as the C2-C60 alkenyl group.
The term “C2-C60 alkynyl group” as used herein may be a monovalent hydrocarbon group having at least one carbon-carbon triple bond in the middle or at a terminus of a C2-C60 alkyl group, and examples thereof may include an ethynyl group, a propynyl group, and the like. The term “C2-C60 alkynylene group” as used herein may be a divalent group having a same structure as the C2-C60 alkynyl group.
The term “C1-C60 alkoxy group” as used herein may be a group represented by —O(A101) (wherein A101 may be the C1-C60 alkyl group), and examples thereof may include a methoxy group, an ethoxy group, an isopropyloxy group, and the like.
The term “C3-C10 cycloalkyl group” as used herein may be a monovalent saturated hydrocarbon cyclic group having 3 to 10 carbon atoms, and examples thereof may include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group (or bicyclo[2.2.1]heptyl group), a bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl group, a bicyclo[2.2.2]octyl group, and the like. The term “C3-C1 cycloalkylene group” as used herein may be a divalent group having a same structure as the C3-C1 cycloalkyl group.
The term “C1-C1 heterocycloalkyl group” as used herein may be a monovalent cyclic group of 1 to 10 carbon atoms, further including, in addition to carbon atoms, at least one heteroatom, as ring-forming atoms, and examples thereof may include a 1,2,3,4-oxatriazolidinyl group, a tetrahydrofuranyl group, a tetrahydrothiophenyl group, and the like. The term “C1-C10 heterocycloalkylene group” as used herein may be a divalent group having a same structure as the C1-C1 heterocycloalkyl group.
The term “C3-C10 cycloalkenyl group” as used herein may be a monovalent cyclic group that has three to ten carbon atoms and at least one carbon-carbon double bond in the ring thereof and no aromaticity, and examples thereof may include a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, and the like. The term “C3-C10 cycloalkenylene group” as used herein may be a divalent group having a same structure as the C3-C10 cycloalkenyl group.
The term “C1-C10 heterocycloalkenyl group” as used herein may be a monovalent cyclic group of 1 to 10 carbon atoms, further including, in addition to carbon atoms, at least one heteroatom, as ring-forming atoms, and having at least one carbon-carbon double bond in the cyclic structure thereof. Examples of a C1-C10 heterocycloalkenyl group may include a 4,5-dihydro-1,2,3,4-oxatriazolyl group, a 2,3-dihydrofuranyl group, a 2,3-dihydrothiophenyl group, and the like. The term “C1-C1 heterocycloalkenylene group” as used herein may be a divalent group having a same structure as the C1-C1 heterocycloalkenyl group.
The term “C6-C60 aryl group” as used herein may be a monovalent group having a carbocyclic aromatic system of 6 to 60 carbon atoms, and the term “C6-C60 arylene group” as used herein may be a divalent group having a carbocyclic aromatic system of 6 to 60 carbon atoms. Examples of a C6-C60 aryl group may include a phenyl group, a pentalenyl group, a naphthyl group, an azulenyl group, an indacenyl group, an acenaphthyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a heptalenyl group, a naphthacenyl group, a picenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, and the like. When the C6-C60 aryl group and the C6-C60 arylene group each include two or more rings, the respective rings may be condensed with each other.
The term “C1-C60 heteroaryl group” as used herein may be a monovalent group having a heterocyclic aromatic system of 1 to 60 carbon atoms, further including, in addition to carbon atoms, at least one heteroatom, as ring-forming atoms. The term “C1-C60 heteroarylene group” as used herein may be a divalent group having a heterocyclic aromatic system of 1 to 60 carbon atoms, further including, in addition to carbon atoms, at least one heteroatom, as ring-forming atoms. Examples of a C1-C60 heteroaryl group may include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, a benzoquinolinyl group, an isoquinolinyl group, a benzoisoquinolinyl group, a quinoxalinyl group, a benzoquinoxalinyl group, a quinazolinyl group, a benzoquinazolinyl group, a cinnolinyl group, a phenanthrolinyl group, a phthalazinyl group, and a naphthyridinyl group. When the C1-C60 heteroaryl group and the C1-C60 heteroarylene group each include two or more rings, the respective rings may be condensed with each other.
The term “monovalent non-aromatic condensed polycyclic group” as used herein may be a monovalent group (for example, having 8 to 60 carbon atoms) having two or more rings condensed to each other, only carbon atoms as ring-forming atoms, and no aromaticity in its entire molecular structure. Examples of a monovalent non-aromatic condensed polycyclic group may include an indenyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, an indenophenanthrenyl group, an indeno anthracenyl group, and the like. The term “divalent non-aromatic condensed polycyclic group” as used herein may be a divalent group having a same structure as the monovalent non-aromatic condensed polycyclic group described above.
The term “monovalent non-aromatic condensed heteropolycyclic group” as used herein may be a monovalent group (for example, having 1 to 60 carbon atoms) having two or more rings condensed to each other, further including, in addition to carbon atoms, at least one heteroatom, as ring-forming atoms, and having non-aromaticity in its entire molecular structure. Examples of a monovalent non-aromatic condensed heteropolycyclic group may include a pyrrolyl group, a thiophenyl group, a furanyl group, an indolyl group, a benzoindolyl group, a naphthoindolyl group, an isoindolyl group, a benzoisoindolyl group, a naphthoisoindolyl group, a benzosilolyl group, a benzothiophenyl group, a benzofuranyl group, a carbazolyl group, a dibenzosilolyl group, a dibenzothiophenyl group, a dibenzofuranyl group, an azacarbazolyl group, an azafluorenyl group, an azadibenzosilolyl group, an azadibenzothiophenyl group, an azadibenzofuranyl group, a pyrazolyl group, an imidazolyl group, a triazolyl group, a tetrazolyl group, an oxazolyl group, an isoxazolyl group, a thiazolyl group, an isothiazolyl group, an oxadiazolyl group, a thiadiazolyl group, a benzopyrazolyl group, a benzimidazolyl group, a benzoxazolyl group, a benzothiazolyl group, a benzoxadiazolyl group, a benzothiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an imidazotriazinyl group, an imidazopyrazinyl group, an imidazopyridazinyl group, an indeno carbazolyl group, an indolocarbazolyl group, a benzofurocarbazolyl group, a benzothienocarbazolyl group, a benzosilolocarbazolyl group, a benzoindolocarbazolyl group, a benzocarbazolyl group, a benzonaphthofuranyl group, a benzonaphthothiophenyl group, a benzonaphthosilolyl group, a benzofurodibenzofuranyl group, a benzofurodibenzothiophenyl group, and a benzothienodibenzothiophenyl group. The term “divalent non-aromatic condensed heteropolycyclic group” as used herein may be a divalent group having a same structure as the monovalent non-aromatic condensed heteropolycyclic group described above.
The term “C6-C60 aryloxy group” as used herein may be a group represented by —O(A102) (wherein A102 may be a C6-C60 aryl group), and the term “C6-C60 arylthio group” as used herein may be a group represented by —S(A103) (wherein A103 may be a C6-C60 aryl group).
The term “C7-C60 arylalkyl group” as used herein may be a group represented by -(A104)(A105) (wherein A104 may be a C1-C54 alkylene group, and A105 may be a C6-C59 aryl group), and the term “C2-C60 heteroarylalkyl group” as used herein may be a group represented by (A106)(A107) (wherein A106 may be a C1-C59 alkylene group, and A107 may be a C1-C59 heteroaryl group).
In the specification, the group “R10a” may be:
In the specification, Q1 to Q3, Q11 to Q13, Q21 to Q23, and Q31 to Q33 may each independently be: hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; a C1-C60 alkyl group; a C2-C60 alkenyl group; a C2-C60 alkynyl group; a C1-C60 alkoxy group; or a C3-C60 carbocyclic group, a C1-C60 heterocyclic group, a C7-C60 arylalkyl group, or a C2-C60 heteroarylalkyl group, each substituted with deuterium, —F, a cyano group, a C1-C60 alkyl group, a C1-C60 alkoxy group, a phenyl group, a biphenyl group, or any combination thereof.
The term “heteroatom” as used herein may be any atom other than a carbon atom or a hydrogen atom. Examples of the heteroatom may include O, S, N, P, Si, B, Ge, Se, and any combination thereof.
The term “the third-row transition metal” as used herein may include Hf, Ta, W, Re, Os, Ir, Pt, Au, and the like.
In the specification, “Ph” refers to a phenyl group, “Me” refers to a methyl group, “Et” refers to an ethyl group, “ter-Bu” or “But” each refer to a tert-butyl group, and “OMe” refers to a methoxy group.
The term “biphenyl group” as used herein may be “a phenyl group substituted with a phenyl group.” For example, the “biphenyl group” may be a substituted phenyl group having a C6-C60 aryl group as a substituent.
The term “terphenyl group” as used herein may be “a phenyl group substituted with a biphenyl group.” For example, the “terphenyl group” may be a substituted phenyl group having, as a substituent, a C6-C60 aryl group substituted with a C6-C60 aryl group.
A maximum number of carbon atoms as recited in the specification is provided only as an example. In an embodiment, a maximum number of carbon atoms of 60 in a C1-C60 alkyl group is only an example, and the definition of an alkyl group may be equally applied to a C1-C20 alkyl group. This may also apply to other cases.
The symbols * and *′ as used herein, unless defined otherwise, each refer to a binding site to a neighboring atom in a corresponding formula.
(4-fluorophenyl)(phenyl)methanone and 2-(ethylamino)ethanol were dissolved in dimethyl sulfoxide and allowed to react in a nitrogen atmosphere at 60° C. for 8 hours. After completion of the reaction, the temperature was lowered to room temperature, and distilled water was added to the reaction solution. After adding the distilled water, an intermediate was obtained by centrifugation.
The Intermediate, 2-mercaptoethanol, and K2CO3 were mixed with a DMF solvent. The resulting mixture was allowed to react at 60° C. for 12 hours. After completion of the reaction, distilled water was added to the reaction product, followed by filtering. The filtrate obtained by the filtration was recrystallized to remove impurities therefrom, so as to prepare Compound 1.
1H NMR (δ ppm: DMSO, 300 MHz): 6.92 (d, 1H), 7.57 (d, 1H), 7.81 (d, 1H), 6.92 (d, 1H), 7.57 (d, 1H), 7.81 (d, 1H), 7.51 (t, 1H), 7.61 (t, 1H), 2.79 (q, 2H), 3.65 (t, 2H), 3.40 (t, 2H), 1.12 to 1.5 (m, 4H)
In a 250 mL three-neck flask, 4 mmol of indium acetate and 12 mmol of palmitic acid were injected together with 100 mL of octadecene, and the mixed solution was heated in a vacuum atmosphere at 120° C. for 1 hour, and the atmosphere was switched to an argon atmosphere, so as to prepare an ln(PA)3 solution.
The temperature of the ln(PA)3 solution was raised to 280° C., and the raised temperature was maintained for 1 hour. 10 mL of 0.2 M tris(trimethylsilyl)phosphine/trioctylphosphine was quickly injected thereto by using a syringe, and was allowed for growth of crystals at 260° C. for 30 minutes. 52 mL of 0.2 M ln(PA)3 solution and 26 mL of 0.2 M tris(trimethylsilyl)phosphine/trioctylphosphine were injected at rates of 1.5 ml/min and 0.75 ml/min, respectively, for 35 minutes. After a 10-minute stabilization period, an InP core was synthesized by cooling the temperature of the reactor to room temperature by removing the heat source. The synthesized InP core was subjected to a purification process. 40 mL of acetone and 10 mL of ethanol were mixed per 10 mL of the InP core solution, and the mixed solution was subjected to centrifugation at 9,000 rpm. The supernatant was removed, and the precipitate was dispersed in toluene.
To form a shell, the synthesized InP core underwent surface treatment. 1.6 mmol of zinc acetate, 3.2 mmol of oleic acid, and 80 mL of trioctylamine were mixed, and the mixture was stirred in a vacuum at 120° C. for 1 hour. After switching to an argon atmosphere, the argon atmosphere was maintained at 280° C. for 1 hour, and the temperature was lowered to 180° C. 12 mL of the InP core solution dispersed in toluene was quickly injected to the mixture by using a syringe. After 5 minutes, 0.2 mL of an HF solution (10 wt % in acetone) was injected into the resulting mixture and rested for 10 minutes, so as to prepare the surface-treated InP core solution. The temperature of the reactor was raised to 320° C. After injecting 15 mmol of 0.4 M Zn(OA)2, 4.0 mmol of Se/trioctylphosphine was injected, so as to grow a ZnSe shell for 1 hour. 3.0 mmol of S/trioctylphosphine was injected to grow a ZnS shell for 1 hour. Acetone and ethanol were added thereto, and the precipitates obtained by centrifugation (9500 rpm/3 min) was re-dispersed in hexane. Quantum dots that were re-dispersed and Compound 1 were mixed in chloroform, and the mixture was subjected to ultrasonication, so as to obtain quantum dots in which native ligans [oleic acid] were substituted with Compound 1.
0.5 g of the quantum dots were added to ethanol, and the mixture, and the precipitates obtained by centrifugation (9500 rpm/3 min) were dispersed in 10 ml of a solvent, hexadecane, so as to prepare Composition 1.
Composition 1 had viscosity of 30 cP (@25° C.).
Composition 2 was prepared in the same manner as in Example 2 by using quantum dots [core: Group II-V element/shell: ZnS coordinated with native ligand (oleic acid), i.e., not coordinated with Compound 1] (10 nm).
A 30 nm-thick thin film was formed by using each of Composition 1 of Example 2 and Composition 2 of Comparative Example 1, and cured at a wavelength of 365 nm (for 30 sec).
When the thin film formed of Composition 1 of Example 2 was washed with each of hexadecane and cyclohexylbenzene that are compositions for a solvent for quantum dot ink, the remnant ratios in both cases were maintained at a ratio of at least 90%.
The thin film formed of Composition 2 of Comparative Example 1 was washed with each of hexadecane and cyclohexylbenzene that are compositions for a solvent for quantum dot ink, the remnant ratios in both cases were less than or equal to 70%.
An ITO glass substrate with a 15 Ω/cm2 (800 Å) was cut to a size of 50 mm×50 mm×0.5 mm, ultrasonicated with isopropyl alcohol and pure water each for 5 minutes, and cleaned by exposure to ultraviolet rays and ozone for 15 minutes. The resultant glass substrate was loaded onto a vacuum deposition apparatus.
On the ITO substrate, a hole injection layer (HIL, poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), an hole transport layer (HTL, poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4′-(N-(4-sec-butylphenyl)diphenylamine)] (TFB), a quantum dot (QD) emission layer (Composition 1), an electron transport layer (ETL, ZnMgO), and a cathode (Al) were sequentially formed.
The HIL, the HTL, the QD emission layer, and the ETL were each formed by spin coating, and the QD emission layer was additionally cured with a wavelength of 365 nm (30 sec) after the coating. The cathode was formed by a deposition method. A thickness of the HIL was 1,400 Å, a thickness of the HTL was 400 Å, a thickness of the QD emission layer was 200 Å, and a thickness of the ETL was 500 Å. After forming the HIL and the HTL in the form of thin films, a VCD process was performed thereon at 10−3 torr, followed by a baking process at 230° C. for 30 minutes. After forming the QD emission layer and the ETL in the form of thin films, a VCD process was performed thereon at 10−3 torr, followed by a baking process at 100° C. for 10 minutes.
A light-emitting device was prepared in the same manner as in Example 3, except that Composition 2 was used to form an emission layer (a curing process was not performed).
To evaluate the characteristics of the light-emitting devices of Comparative Example 2 and Example 3, the driving voltage was measured, and results are shown in Table 1:
Referring to Table 1, it was confirmed that the light-emitting device of Example 3 had increased efficiency compared to the light-emitting device of Comparative Example 2.
Compared to the emission layer of the light-emitting device of Comparative Example 2 in which quantum dots were simply stacked, quantum dots in the emission layer of the light-emitting device of Example 3 were cross-linked and connected to each other, and thus had high packing density and accordingly high layer stability. Based on these differences, it was confirmed that the light-emitting device of Example 3 had increased efficiency compared to the light-emitting device of Comparative Example 2.
According to embodiments, a light-emitting device may have excellent performance, as compared with the related art.
Embodiments have been disclosed herein, and although terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for the purposes of limitation. In some instances, as would be apparent by one of ordinary skill in the art, features, characteristics, and/or elements described in connection with an embodiment may be used singly or in combination with features, characteristics, and/or elements described in connection with other embodiments unless otherwise specifically indicated. Accordingly, it will be understood by those of ordinary skill in the art that various changes in form and details may be made without departing from the spirit and scope of the disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2023-0014404 | Feb 2023 | KR | national |
