Patent Application
20250236791
This application claims priority to and benefits of Korean Patent Application No. 10-2024-0008935 under 35 U.S.C. § 119, filed on Jan. 19, 2024, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference.
Embodiments relate to a quantum dot complex, a quantum dot composition including the same, an electronic device including the quantum dot complex, and an electronic equipment including the quantum dot complex.
Quantum dots are nano crystals of a semiconductor material and are materials that exhibit a quantum confinement effect. When quantum dots receive light from an excitation source and reach an energy excited state, the quantum dots emit energy according to a corresponding energy band gap. Quantum dots of a same material may emit light having different wavelengths depending on the size of the quantum dots. Accordingly, the size of quantum dots may be adjusted to obtain light in a desired wavelength range and exhibit characteristics such as excellent color purity and high luminous efficiency. Therefore, quantum dots are applicable to various devices.
Quantum dots may be utilized as materials performing various optical functions (for example, a photoconversion function) of optical members. Quantum dots are nano-sized semiconductor nanocrystals, and can have different energy band gaps by controlling the size and composition of the nanocrystals, thereby emitting light of various emission wavelengths.
Optical members including such a quantum dot may have a thin film form, for example, a thin film form patterned for each subpixel. Such an optical member may also be used as a color conversion member of a device including various light sources.
However, the quantum dots are readily oxidized by moisture and oxygen, and when they are oxidized, the efficiency thereof is reduced.
This issue can be addressed by coordinating reactive ligands around quantum dots. However, it was difficult to effectively prevent oxidation of quantum dots due to desorption and rearrangement of the ligands.
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 quantum dot complex with improved photostability, a quantum dot composition including the same, an electronic device including the same, and an electronic equipment including the same.
Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the embodiments of the disclosure.
According to embodiments, a quantum dot complex may include: a quantum dot; and a first ligand and a second ligand, each coordinated on a surface of the quantum dot, wherein
the first ligand may be a chain-shaped bidentate ligand including an ethylene glycol group (—OCH2CH2O—), and the second ligand may be a ligand including an acryloyl group (CH2═CHC(═O)—) and an ethylene glycol group.
In an embodiment, the first ligand may be represented by Formula 1:
In Formula 1,
In an embodiment, R1 may be a methyl group; and R2 may each independently be hydrogen or a methyl group.
In an embodiment, R1 may be a methyl group; and R2 may each be hydrogen.
In an embodiment, R1 and R2 may each be a methyl group.
In an embodiment, a1 may be 2 or 3.
In an embodiment, a2 may be 3; and a3 may be 1.
In an embodiment, the first ligand may be selected from the following compounds:
In an embodiment, the second ligand may further include a carboxylate group (—C(═O)OH); and the second ligand may be coordinated on the surface of the quantum dot by the carboxylate group.
In an embodiment, the second ligand may be the following compound:
In an embodiment, a total amount of the first ligand and the second ligand may be in a range of about 15 wt % to about 25 wt %, based on a total weight of quantum dot complex.
In an embodiment, a molar ratio of the first ligand to the second ligand may be in a range of about 0.3:1 to about 0.8:1.
In an embodiment, 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 a combination thereof.
In an embodiment, the quantum dot may include a core, and a shell covering the core.
In an embodiment, the quantum dot may include a copper indium gallium sulfide (CIGS) core, and a ZnS shell.
According to embodiments, a quantum dot composition may include the quantum dot complex, and a solvent.
According to embodiments, an electronic device may include the quantum dot complex.
In an embodiment, the electronic device may further include a color filter and/or a color conversion layer, wherein the color filter and/or the color conversion layer may include the quantum dot complex.
In an embodiment, the electronic device may further include a light source, wherein the light source may be a light-emitting device including a first electrode, a second electrode facing the first electrode, and an emission layer between the first electrode and the second electrode.
According to embodiments, an electronic equipment may include the electronic device, wherein the electronic equipment may be a flat panel display, a curved display, a computer monitor, a medical monitor, a television, an advertisement board, an indoor light, an outdoor light, a signal light, a head-up display, a fully transparent display, a partially transparent display, a flexible display, a rollable display, a foldable display, a stretchable display, a laser printer, a telephone, a mobile phone, a tablet computer, a phablet, a personal digital assistant (PDA), a wearable device, a laptop computer, a digital camera, a camcorder, a viewfinder, a microdisplay, a three-dimensional (3D) display, a virtual reality display, an augmented reality display, a vehicle, a video wall including multiple displays tiled together, a theater screen, a stadium screen, a phototherapy device, or a signboard.
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 accompanying drawings are included to provide a further understanding of the embodiments, and are incorporated in and constitute a part of this specification.
The drawings illustrate embodiments of the disclosure and principles thereof. The above and other aspects and features of the disclosure will become 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 reference characters refer to like elements throughout.
In the specification, 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 specification, 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.
In the specification, the expressions used in the singular such as “a”, “an”, and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.
In the specification, 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 consisting of” for the purpose of its meaning and interpretation. For example, “at least one of A, B, and C” may be understood to mean A only, B only, C only, or any combination of two or more of A, B, and C, such as ABC, ACC, BC, or CC. 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.
In the specification, the term “quantum dot complex” may refer to a material that includes a quantum dot and a ligand that is coordinated to the quantum dot. The quantum dot may include a core and a shell surrounding the core.
In the specification, the term “photo conversion efficiency (PCE)” may refer to a ratio of fluorescent photons to excitation photons.
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.
According to embodiments, a quantum dot complex may include: a quantum dot; and a first ligand and a second ligand, each coordinated on a surface of the quantum dot. The first ligand may be a chain-shaped bidentate ligand including an ethylene glycol group (—OCH2CH2O—), and the second ligand may be a ligand including an acryloyl group (CH2═CHC(═O)—) and an ethylene glycol group.
Quantum dot ligands may protect quantum dots and may allow quantum dots to be evenly dispersed in a solvent. In order to perform these functions, a quantum dot ligand according to an embodiment may include two types of ligands with different structures.
In an embodiment, the first ligand may be represented by Formula 1:
In Formula 1,
In an embodiment, R1 may be a methyl group or an ethyl group, and R2 may each be hydrogen. For example, in an embodiment, R1 may be a methyl group, and R2 may each be hydrogen.
In an embodiment, R1 may be a methyl group or an ethyl group, and R2 may each independently be hydrogen or a methyl group. For example, in an embodiment, R1 may be a methyl group, and R2 may independently be hydrogen or a methyl group.
In an embodiment, R1 and R2 may each be a methyl group.
In an embodiment, a1 may be 2 or 3.
In an embodiment, a2 may be 3.
In an embodiment, a3 may be 1.
For example, in an embodiment, a1 may be 2 or 3, a2 may be 3, and a3 may be 1.
In an embodiment, the first ligand may be selected from the following compounds:
The first ligand has a chain structure that includes an ethylene glycol group (—OCH2CH2O—), thereby increasing the solubility of the quantum dot in a hydrophilic solvent and minimizing contact between the quantum dot and an external source that can oxidize the quantum dot. The first ligand may form a more stable bond to the quantum dot by coordinating onto the quantum dot at two sites. With respect to the first ligand, due to the inclusion of a short alkoxy group at the end of the chain, greater polarity may be obtained than from a light of having an aryloxy group or a long alkoxy group at the end of the chain. In an embodiment, a hydrogen atom in the ethylene glycol group of the first ligand may be substituted with a short alkyl group.
The second ligand may increase the dispersibility of the quantum dot complex in a hydrophilic solvent due to the inclusion of an acryloyl group (CH2═CHC(═O)—) and an ethylene glycol group. When the quantum dot complex is evenly dispersed in a solvent, stress caused by light may also be dispersed, which can improve light resistance of a quantum dot complex film.
In an embodiment, the second ligand may further include a carboxylate group (—C(═O)OH), and the second ligand may be coordinated on a surface of the quantum dot by the carboxylate group. The second ligand may improve photostability by coordinating onto a surface of the quantum dot by a carboxylate group.
In an embodiment, the second ligand may include the following compound:
The quantum dot complex according to an embodiment may have improved light resistance due to the inclusion of both the first ligand and the second ligand. This is believed to be due to achieving a balance between strengthening the binding of the ligands to the quantum dot and improving the dispersibility of the ligands in the solvent.
In an embodiment, a total amount of the first ligand and the second ligand in the quantum dot complex may be in a range of about 15 wt % to about 25 wt %, based on a total weight of the quantum dot complex. For example, in the quantum dot complex, a sum of a total amount of the first ligand, and a total amount of the second ligand may be in a range of about 15 wt % to about 25 wt %, based on a total weight of the quantum dot complex. When the total amount of the first ligand and the second ligand is within the range above, light resistance of the quantum dot complex may be improved. The first ligand and the second ligand may be introduced into the quantum dot complex by exchanging with a native ligand. In an embodiment, the native ligand of the quantum dot complex may include, for example, oleic acid, lauric acid, or stearic acid, but embodiments are not limited thereto.
In an embodiment, a molar ratio of the first ligand to the second ligand may be in a range of about 0.3:1 to about 0.8:1. When the molar ratio of the first ligand to the second ligand is within this range, light resistance of the quantum dot complex may be improved.
In an embodiment, the quantum dot may have a core-shell structure that includes a core including a semiconductor compound and a shell including a semiconductor compound.
In an embodiment, 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 a 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, or MgS; a ternary compound, such as CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, or MgZnS; a quaternary compound, such as CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, or HgZnSTe; or a 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, InSb, and the like; a ternary compound, such as GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InNP, InAlP, InNAs, InNSb, InPAs, InPSb, and the like; a quaternary compound, such as GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, and the like; or any combination thereof. In an embodiment, a 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, etc.
Examples of a Group III-VI semiconductor compound may include: a binary compound, such as GaS, GaSe, GazSe3, GaTe, InS, InSe, In2S3, In2Se3, or InTe; a ternary compound, such as InGaSs, or InGaSes; or a combination thereof.
Examples of a Group I-III-VI semiconductor compound may include: a ternary compound such as AgInS, AgInS2, CuInS, CuInS2, CuGaO2, AgGaO2, or AgAlO2; a quaternary compound such as AgInGaS or AgInGaS2; or a combination thereof.
Examples of a Group IV-VI semiconductor compound may include: a binary compound, such as SnS, SnSe, SnTe, PbS, PbSe, or PbTe; a ternary compound, such as SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, or SnPbTe; a quaternary compound, such as SnPbSSe, SnPbSeTe, or SnPbSTe; or a combination thereof.
Examples of a Group IV element or compound may include: a single element material, such as Si or Ge; a binary compound, such as SiC or SiGe; or a combination thereof.
Each element included in a compound such as a binary compound, a ternary compound, or a quaternary compound may be present in a particle at a uniform concentration or at a non-uniform concentration.
In an embodiment, examples of a semiconductor compound included 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 a combination thereof.
In an embodiment, the quantum dot may include a copper indium gallium sulfide (CIGS) core and a ZnS or GaS shell.
In embodiments, a quantum dot may be in the form of a spherical particle, a pyramidal particle, a multi-arm particle, a cubic nanoparticle, a nanotube particle, a nanowire particle, a nanofiber particle, or a nanoplate particle.
Since the energy band gap can be controlled by adjusting the size of a quantum dot, a light-emitting device that emits light of various wavelengths may be implemented by using quantum dots of different sizes. For example, the size of the quantum dot may be selected to emit red light or green light. In an embodiment, the size of the quantum dot may be configured to emit white light by a combination of light of various colors.
According to embodiments, a quantum dot composition may include the quantum dot complex.
In an embodiment, the quantum dot composition may include a quantum dot complex, a crosslinkable monomer, and an initiator.
The crosslinkable monomer may be, for example, an acrylic monomer. The crosslinkable monomer may include, for example, 1,6-hexanediol diacrylate, 2-ethylhexyl(meth)acrylate, ethyl(meth)acrylate, methyl(meth)acrylate, n-propyl(meth)acrylate, isopropyl(meth)acrylate, pentyl(meth)acrylate, n-octyl(meth)acrylate, isooctyl(meth)acrylate, isononyl(meth)acrylate, n-butyl(meth)acrylate, isobutyl(meth)acrylate, n-hexyl(meth)acrylate, n-nonyl(meth)acrylate, isoamyl(meth)acrylate, n-decyl(meth)acrylate, isodecyl(meth)acrylate, dodecyl(meth)acrylate, isobornyl(meth)acrylate, cyclohexyl(meth)acrylate, phenyl(meth)acrylate, benzyl(meth)acrylate, isostearyl(meth)acrylate, 2-methylbutyl(meth)acrylate, or a combination thereof.
The initiator may include, for example, diphenyl(2,4,6-trimethylbenzoyl) phosphine oxide, 4-acryloxybenzophenone, 2,2-dimethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenyl-1-propan-1-one, ethyl(2,4,6-trimethylbenzoyl)phenyl phosphinate, bisacylphosphine oxide, or a combination thereof.
In an embodiment, the quantum dot composition may further include an additive, in addition to the crosslinkable monomer and the initiator. The additive may include, for example, a material to increase photostability, thermal stability, or storage stability of the quantum dot complex. The additive may include, for example, ultraviolet (UV) stabilizers, heat stabilizers, or reaction inhibitors.
In an embodiment, the quantum dot composition may include the quantum dot complex and a solvent.
In an embodiment, the solvent may be hydrophobic or hydrophilic.
In an embodiment, the hydrophobic solvent may include at least one of an aliphatic hydrocarbon system and an aromatic hydrocarbon system.
For example, the hydrophobic solvent may include at least one of: an alkane such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, dodecane, hexadecane, and oxadecane; a haloalkane such as dichloromethane, 1,2-dichloroethane, and 1,1,2-trichloroethane; a cycloalkane such as cyclohexane, methylcyclohexane, etc.; an aromatic hydrocarbon such as toluene, xylene, mesitylene, ethylbenzene, n-hexylbenzene, cyclohexylbenzene, trimethylbenzene, and tetrahydronaphthalene; and an aryl halide such as chlorobenzene, o-dichlorobenzene, and cyclohexylbenzene.
In an embodiment, the hydrophilic solvent may include at least one of an alcohol group, an ether group, a ketone group, and an ester group.
For example, the hydrophilic solvent may include at least one of: a alkylene glycol alkyl ether such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, and propylene glycol methyl ethyl ether; a diethylene glycol dialkyl ether such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, and diethylene glycol dibutyl ether; an alkylene glycol alkyl ether acetate such as methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and propylene glycol monopropyl ether acetate; an alkoxyalkyl acetate such as methoxybutyl acetate and methoxypentyl acetate; an aromatic hydrocarbon such as benzene, toluene, xylene, and mesitylene; a ketone such as methyl ethyl ketone, acetone, methyl amyl ketone, methyl isobutyl ketone, and cyclohexanone; an alcohol such as ethanol, propanol, butanol, hexanol, cyclohexanol, ethylene glycol, and glycerin; an ester such as 3-ethoxypropionic acid ethyl ester, 3-methoxypropionic acid methyl ester, and 3-phenyl-propionic acid ethyl ester; a cyclic ester such as γ-butyrolactone; and methoxybenzene (anisole).
In an embodiment, a viscosity (@25° C.) of the composition may be in a range of about 2 cP to about 30 cP.
When the viscosity is within this range, the composition according to an embodiment may be suitable for forming a layer using a solution process, for example, by a spin coating process or an inkjet process.
Hereinafter, the structure and a manufacturing method of the light-emitting device 10 according to an embodiment 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 transflective 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 transflective 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. In an embodiment, the first electrode 110 may have a three-layer structure of ITO/Ag/ITO.
The interlayer 130 may be disposed above the first electrode 110. The interlayer 130 may include an emission layer.
The interlayer 130 may further include a hole transport region between the first electrode 110 and the emission layer, and an electron transport region between the emission layer and the second electrode 150.
The interlayer 130 may further include, in addition to various organic materials, a metal-containing compound such as an organometallic compound, an inorganic material such as quantum dots, or the like.
In an embodiment, 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 adjacent units among the two or more emitting units. When the interlayer 130 includes two or more emitting units and the at least one charge generation layer as described above, 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 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 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.
In embodiments, the hole transport region may include a compound represented by Formula 201, a compound represented by Formula 202, or any combination thereof:
In an embodiment, the 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 described in connection with R10a, ring CY201 to ring CY204 may each independently be a C3-C20 carbocyclic group or a C1-C20 heterocyclic group, and at least one hydrogen in Formulae CY201 to CY217 may be unsubstituted or substituted with R10a which is described herein.
In an embodiment, in Formulae CY201 to CY217, ring CY201 to ring CY204 may each independently be a benzene group, a naphthalene group, a phenanthrene group, or an anthracene group.
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 CY203.
In an embodiment, 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 an embodiment, in Formula 201, xa1 may be 1, R201 may be a group represented by one of Formulae CY201 to CY203, xa2 may be 0, and R202 may be a group represented by one of Formulae CY204 to CY207.
In an embodiment, 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 an embodiment, 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 an embodiment, the compound represented by Formula 201 and the compound represented by Formula 202 may each not include groups represented by Formulae CY201 to CY217.
In an embodiment, 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), polyanine/dodecybenzenesulfonic 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 a combination thereof, a thickness of the hole injection layer may be in a range of about 50 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 layer 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 the ranges described above, satisfactory hole transporting characteristics may be obtained without a substantial increase in driving voltage.
The emission auxiliary layer may increase light-emission efficiency by compensating for an optical resonance distance of a wavelength of light emitted by an emission layer, and the electron-blocking layer may block 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 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, a lowest unoccupied molecular orbital (LUMO) energy level of the p-dopant may be equal to or less than about-3.5 eV.
In an embodiment, the p-dopant may include a quinone derivative, a cyano group-containing compound, a compound including element EL1 and element EL2, or a combination thereof.
Examples of a quinone derivative may include TCNQ and F4-TCNQ.
Examples of a cyano group-containing compound may include HAT-CN and a compound represented by Formula 221:
In Formula 221,
In the compound including element EL1 and the element EL2, element EL1 may be a metal, a metalloid, or a combination thereof, and element EL2 may be a non-metal, a metalloid, or a 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.); 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 a metalloid may include silicon (Si), antimony (Sb), and tellurium (Te).
Examples of a non-metal may include oxygen (O) and a halogen (for example, F, Cl, Br, I, etc.).
Examples of a 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 a 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, MoOs, MO2O5, etc.), and a rhenium oxide (for example, ReOs, etc.).
Examples of a 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 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, and CsI.
Examples of an 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 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, HfI4, etc.), a vanadium halide (for example, VF3, VCl3, VBr3, VI3, etc.), a niobium halide (for example, NbF3, NbCl3, NbBr3, NbI3, etc.), a tantalum halide (for example, TaF3, TaCl3, TaBr3, TaI3, etc.), a chromium halide (for example, CrF3, CrCl3, CrBr3, CrI3, etc.), a molybdenum halide (for example, MoF3, MoCl3, MoBr3, MoI3, etc.), a tungsten halide (for example, WF3, WCl3, WBr3, WI3, etc.), a manganese halide (for example, MnF2, MnCl2, MnBr2, MnI2, etc.), a technetium halide (for example, TcF2, TcCl2, TcBr2, TcI2, etc.), a rhenium halide (for example, ReF2, ReCl2, ReBr2, ReI2, etc.), an iron halide (for example, FeF2, FeCl2, FeBr2, 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 a post-transition metal halide may include a zinc halide (for example, ZnF2, ZnCl2, ZnBr2, Znl2, etc.), an indium halide (for example, InI3, etc.), and a tin halide (for example, SnI2, etc.).
Examples of a lanthanide metal halide may include YbF, YbF2, YbF3, SmF3, YbCl, YbCl2, YbCl3 SmCl3, YbBr, YbBr2, YbBr3, SmBr3, YbI, YbI2, YbI3, and SmI3.
Examples of a metalloid halide may include an antimony halide (for example, SbCl5, etc.).
Examples of a 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, CuzTe, 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 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 may be separated from each other, to emit white light. In embodiments, the emission layer may include two or more materials of a red light-emitting material, a green light-emitting material, and a blue light-emitting material, in which the two or more materials may be mixed with each other in a single layer, to emit white light.
The emission layer may include a host and a dopant. The dopant may include a phosphorescent dopant, a fluorescent dopant, or any combination thereof.
An amount of the dopant in the emission layer may be in a range of about 0.01 parts by weight to about 15 parts by weight, based on 100 parts by weight of the host.
In embodiments, the emission layer may include the quantum dot complex described above (hereinafter also referred to as “quantum dot”).
In an embodiment, the emission layer may include a delayed fluorescence material. The delayed fluorescent material may serve as a host or as a dopant in the emission layer.
A thickness of the emission layer may be in a range of about 100 Å to about 1,000 Å. For example, 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 any of the ranges described above, excellent luminescence characteristics may be obtained without a substantial increase in driving voltage.
The emission layer may include a quantum dot.
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. Quantum dots may emit light of various emission wavelengths by adjusting a ratio of elements in a quantum dot compound.
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 include mixing a precursor material with an organic solvent and growing a quantum dot crystal particle. When the crystal grows, the organic solvent naturally serves as a dispersant coordinated on the surface of the quantum dot crystal and controls the growth of the crystal. Accordingly, the growth of quantum dot particles can 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).
A 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 a 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, or MgS; a ternary compound, such as CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, or MgZnS; a quaternary compound, such as CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, or HgZnSTe; or a 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, InSb, and the like; a ternary compound, such as GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InNP, InAlP, InNAs, InNSb, InPAs, InPSb, and the like; a quaternary compound, such as GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, and the like; or a combination thereof. In an embodiment, a 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, etc.
Examples of a Group III-VI semiconductor compound may include: a binary compound, such as GaS, GaSe, GazSe3, GaTe, InS, InSe, In2S3, In2Se3, or InTe; a ternary compound, such as InGaSs, or InGaSe3; or a combination thereof.
Examples of a Group I-III-VI semiconductor compound may include: a ternary compound such as AgInS, AgInS2, CuInS, CuInS2, CuGaO2, AgGaO2, or AgAlO2; a quaternary compound such as AgInGaS or AgInGaS2; or a combination thereof.
Examples of a Group IV-VI semiconductor compound may include: a binary compound, such as SnS, SnSe, SnTe, PbS, PbSe, or PbTe; a ternary compound, such as SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, or SnPbTe; a quaternary compound, such as SnPbSSe, SnPbSeTe, or SnPbSTe; or a combination thereof.
Examples of a Group IV element or compound may include: a single element material such as Si or Ge; a binary compound, such as SiC or SiGe; or a combination thereof.
Each element included in a compound, such as a binary compound, a ternary compound, or a quaternary compound, may be present in a quantum dot particle at a uniform concentration or at a non-uniform concentration.
In an embodiment, a quantum dot may have a single structure in which the concentration of each element in the quantum dot is uniform, or a 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 a quantum dot may serve as a protective layer that prevents chemical degeneration of the core to maintain semiconductor characteristics, and/or may serve as a charging layer that imparts electrophoretic characteristics to the quantum dot. The shell may be a single layer or multilayered. An interface between the core and the shell may have a concentration gradient in which the concentration of an element that is present in the shell decreases toward the core.
A shell of a quantum dot may include a metal, a metalloid, a non-metal, a semiconductor compound, or a combination thereof. Examples of a metal oxide, a metalloid oxide, 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, or NiO; a ternary compound, such as MgAl2O4, CoFe2O4, NiFe2O4, or CoMn2O4; or a combination thereof.
Examples of a semiconductor compound may include, as described herein: a Group II-VI semiconductor compound; a Group III-V semiconductor compound; a Group III-VI semiconductor compound; a Group I-III-VI semiconductor compound; a Group IV-VI semiconductor compound; and a combination thereof. For example, the semiconductor compound may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, or a combination thereof.
A full width at half maximum (FWHM) of an emission spectrum of the quantum dot may be equal to or less than about 45 nm. For example, a FWHM of an emission spectrum of the quantum dot may be equal to or less than about 40 nm. For example, a FWHM of an emission spectrum of the quantum dot may be equal to or less than about 30 nm. Within any of these ranges, color purity or color reproducibility may be improved. Light emitted through a quantum dot may be emitted in all directions, so that a wide viewing angle may be improved.
In embodiments, a quantum dot may be in the form of a spherical particle, a pyramidal particle, a multi-arm particle, a cubic nanoparticle, a nanotube particle, a nanowire particle, a nanofiber particle, or a nanoplate particle.
Since an energy band gap may be adjusted by controlling the size of the quantum dot, light having various wavelength bands may be obtained from a 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 embodiments, the size of the quantum dot may be adjusted to emit red light, green light, and/or blue light. In an embodiment, the size of the quantum dot may be configured to emit white light by a combination of light of various colors.
The electron transport region may have a structure consisting of a layer consisting of a single material, a structure consisting of a layer including different materials, or a structure including multiple layers including different materials.
The electron transport region may include a hole-blocking layer, an electron transport layer, an electron injection layer, or a combination thereof.
In an embodiment, 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 the layers of each structure may be stacked from an emission layer in its respective stated order, but the structure of the electron transport region is not limited thereto.
The electron transport region (for example, a hole-blocking layer or an electron transport layer in the electron transport region) may include a metal-free compound including at least one π electron-deficient nitrogen-including 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, in Formula 601, when xe11 is 2 or more, two or more of Ar601 may be linked together via a single bond.
In an embodiment, in Formula 601, Ar601 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 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.
In an embodiment, the electron transport region may include one of Compounds ET1 to ET45, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), Alq3, BAlq, TAZ, NTAZ, or any combination thereof:
A thickness of the electron transport region may be in a range of about 100 Å to about 5,000 Å. For example, 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 a hole-blocking layer, an electron transport layer, or a combination thereof, a thickness of the hole-blocking 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 in a range of about 100 Å to about 1,000 Å. For example, the thickness of the hole-blocking layer may 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, the electron transport layer, and/or the electron transport region are within the ranges described above, satisfactory electron transporting characteristics may be obtained without a substantial increase in driving voltage.
The electron transport region (for example, an electron transport layer in the electron transport region) may further include, in addition to the materials described above, a metal-containing material.
The metal-containing material may include an alkali metal complex, an alkaline earth metal complex, or any combination thereof. A metal ion of the alkali metal complex may be a Li ion, a Na ion, a K ion, a Rb ion, or a Cs ion, and a metal ion of the alkaline earth metal complex may be a Be ion, a Mg ion, a Ca ion, a Sr ion, or a Ba ion.
A ligand coordinated with a metal ion of an alkali metal complex or with a metal ion of an alkaline earth-metal complex may each independently 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 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, or K2O; an alkali metal halide, such as LiF, NaF, CsF, KF, LiI, NaI, CsI, or KI; or any combination thereof. The alkaline earth metal-containing compound may include an alkaline earth metal oxide, such as BaO, SrO, CaO, BaxSr1-xO (wherein x is a real number satisfying 0<x<1), or BaxCa1-xO (wherein x is a real number satisfying 0<x<1). 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 a 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: 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 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 an alkali metal-containing compound (for example, an alkali metal halide); or the electron injection layer may consist of an alkali metal-containing compound (for example, an alkali metal halide), and an alkali metal, an alkaline earth metal, a rare earth metal, or a combination thereof. For example, the electron injection layer may be a KI:Yb co-deposited layer, an RbI:Yb co-deposited layer, 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.
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 any of 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 interlayer 130. The second electrode 150 may be a cathode, which is an electron injection electrode. When the second electrode 150 is a cathode, a material for forming the second electrode 150 may include a material having a low-work function, such as 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 transflective electrode, or a reflective electrode.
The second electrode 150 may have a single-layer structure or a multilayered structure.
The light-emitting device 10 may include a first capping layer arranged outside the first electrode 110, and/or a second capping layer arranged 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 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.
Light generated in an emission layer of the interlayer 130 of the light-emitting device 10 may be extracted through the first electrode 110, which may be a transflective electrode or a transmissive electrode, and through the first capping layer to the outside. Light generated in an emission layer of the interlayer 130 of the light-emitting device 10 may be extracted through the second electrode 150, which may be a transflective electrode or a transmissive electrode, and through the second capping layer to the outside.
The first capping layer and the second capping layer may each increase external emission efficiency according to the principle of constructive interference. Accordingly, 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 equal to or greater than about 1.6 (with respect to a wavelength of about 589 nm).
The first capping layer and the second capping layer may each independently be an organic capping layer including an organic material, an inorganic capping layer including an inorganic material, or an organic-inorganic composite capping layer including an organic material and an inorganic material.
At least one of the first capping layer and the second capping layer may each independently include 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 be optionally 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 an embodiment, 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 an embodiment, 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, an electronic apparatus including the light-emitting device may be a light-emitting apparatus, an authentication apparatus, or the like.
The electronic apparatus (for example, a light-emitting apparatus) may further include a color filter, a color conversion layer, or a color filter and a color conversion layer, in addition to the light-emitting device. The color filter and/or the color conversion layer may be disposed in at least one traveling direction of light emitted from the light-emitting device. For example, light emitted from the light-emitting device may be blue light or white light. A further description of the light-emitting device may be the same as described above.
The electronic apparatus may include a substrate. The substrate may include subpixels, the color filter may include color filter regions respectively corresponding to the subpixels, and the color conversion layer may include color conversion regions respectively corresponding to the subpixels.
A pixel defining layer may be disposed between the subpixels to define each subpixel.
The color filter may further include color filter regions and light blocking patterns disposed between the color filter regions, and the color conversion layer may further include color conversion regions and light blocking patterns disposed between the color conversion regions.
The color filter regions (or the color conversion regions) may include a first region that emits first color light, a second region that emits second color light, and/or a third region that emits third color light, and the first color light, the second color light, and/or the third color light may have different maximum emission wavelengths. For example, the first color light may be red light, the second color light may be green light, and the third color light may be blue light. In an embodiment, the color filter regions (or the color conversion regions) may include quantum dots. For example, the first region may include a red quantum dot, the second region may include a green quantum dot, and the third region may not include a quantum dot. Further descriptions of the quantum dot may be the same as described herein. The first region, the second region, and/or the third region may each further include a scatterer.
The regions including a quantum dot may be formed using a quantum dot composition that includes a quantum dot complex according to an embodiment.
In an embodiment, the light-emitting device may emit first light, the first region may absorb the first light to emit first-first color light, the second region may absorb the first light to emit second-first color light, and the third region may absorb the first light to emit third-first color light. The first-first color light, the second-first color light, and the third-first color light may have different maximum emission wavelengths. 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 (TFT), 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.
The TFT 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, or the like.
The electronic apparatus may further include an encapsulation part that seals the light-emitting device. The encapsulation part may be disposed between the color filter and/or the color conversion layer and the light-emitting device. The encapsulation part may allow light from the light-emitting device to be emitted to the outside and while blocking ambient air and moisture from permeating into the light-emitting device. The encapsulation part may be an encapsulation substrate including a transparent glass substrate or a plastic substrate. The encapsulation part may be a thin film encapsulation layer that includes at least one of an organic layer and/or an inorganic layer. When the encapsulation part is a thin film encapsulation layer, the electronic apparatus may be flexible.
Various functional layers may be further included on the encapsulation part, in addition to the color filter and/or the color conversion layer, according to a use of the electronic apparatus. Examples of a functional layer may include a touch screen layer, a polarization layer, and the like. The touch screen layer may be a resistive 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 a biometric information collecting unit, in addition to the light-emitting device described above.
The electronic apparatus may be applied to various displays, a light source, an illuminator, a personal computer (for example, a laptop computer), a mobile phone, a digital camera, an electronic notebook, an electronic dictionary, an electronic game machine, a medical apparatus (for example, an electronic thermometer, a blood pressure monitor, a blood glucose meter, a pulse measuring apparatus, a pulse wave measuring apparatus, an electrocardiogram display apparatus, an ultrasonic diagnostic apparatus, or an endoscope display apparatus), a fish detector, various measuring apparatuses, instruments (for example, instruments for vehicles, aircrafts, or ships), a projector, or 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 disposed on the substrate 100. The buffer layer 210 may prevent penetration of impurities through the substrate 100 and may provide a flat surface on the substrate 100.
The TFT may be disposed on the buffer layer 210. The TFT may include an 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 may be disposed on the active layer 220 to insulate the active layer 220 from the gate electrode 240, and the gate electrode 240 may be disposed on the gate insulating film 230.
An interlayer insulating film 250 may be disposed on the gate electrode 240. The interlayer insulating film 250 may be disposed between the gate electrode 240 and the source electrode 260 and between the gate electrode 240 and the drain electrode 270, to insulate the gate electrode 240 from the source electrode 260 and to insulate the gate electrode 240 from the drain electrode 270.
The source electrode 260 and the drain electrode 270 may be disposed on the interlayer insulating film 250. The interlayer insulating film 250 and the gate insulating film 230 may be formed to expose 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 the 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 layer, an organic insulating layer, or a combination thereof. The light-emitting device may be provided on the passivation layer 280. The light-emitting device may include a first electrode 110, an interlayer 130, and a second electrode 150.
The first electrode 110 may be disposed on the passivation layer 280. The passivation layer 280 may not completely cover the drain electrode 270 and may expose a region of the drain electrode 270. The first electrode 110 may be disposed to be connected (for example, electrically connected) to the exposed region of the drain electrode 270.
A pixel defining film 290 including an insulating material may be disposed on the first electrode 110. The pixel defining film 290 may expose a region of the first electrode 110, and the interlayer 130 may be formed on the exposed region of the first electrode 110. The pixel defining film 290 may be a polyimide or polyacrylic organic film. Although not illustrated in
The second electrode 150 may be disposed 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 part 300 may be disposed on the capping layer 170. The encapsulation part 300 may be disposed on the light-emitting device to protect the light-emitting device from moisture and/or oxygen. The encapsulation part 300 may include: an inorganic film including silicon nitride (SiNx), silicon oxide (SiOx), indium tin oxide, indium zinc oxide, or a combination thereof; an organic film including polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, polyethylene sulfonate, polyoxymethylene, polyarylate, hexamethyldisiloxane, an acryl-based resin (for example, polymethyl methacrylate or a polyacrylic acid), an epoxy-based resin (for example, aliphatic glycidyl ether (AGE)), or a combination thereof; or a combination of an inorganic film and an organic film.
The electronic apparatus of
According to an embodiment, a light-emitting device included in the electronic apparatus of
Each layer included in the hole transport region, the emission layer, each layer included in the electron transport region, and the like may be formed in selected regions using various methods such as vacuum deposition, spin coating, casting, a Langmuir-Blodgett (LB) method, ink-jet printing, laser-printing, and laser-induced thermal imaging (LITI).
The color filter region, the color conversion region, and the like may be formed in selected regions using spin coating, casting, ink-jet printing, or the like.
When each layer included in the hole transport region, the emission layer, and each layer included in the electron transport are each formed through vacuum deposition, the vacuum deposition may be performed at a deposition temperature in a range of about 100° C. to about 500° C., a vacuum degree in a range of about 10-8 torr to about 10-3 torr, and a deposition rate in a range of about 0.01 Å/see to about 100 Å/see, in consideration of a material to be included in a layer to be formed and a structure of the layer to be formed.
When each layer included in the hole transport region, the emission layer, and each layer included in the electron transport are each formed through spin coating, the spin coating may be performed at a coating rate in a range of about 2,000 revolutions per minute (rpm) to about 5,000 rpm and a heat treatment temperature in a range of about 80° C. to about 200° C., in consideration of a material to be included in a layer to be formed and a structure of the layer to be formed.
A quantum dot composition according to an embodiment may be used in a solution process including spin coating, ink-jet printing, or the like.
The term “C3-C60 carbocyclic group” as used herein may be a cyclic group consisting of carbon atoms as the only ring-forming atoms and having three to sixty carbon atoms. The term “C1-C60 heterocyclic group” as used herein may be a cyclic group 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 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. In an embodiment, the number of ring-forming atoms in a C1-C60 heterocyclic group may be 3 to 61.
The term “cyclic group” as used herein may be a C5-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. The term “π electron-deficient nitrogen-including 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 an embodiment,
The terms “cyclic group,” “C3-C60 carbocyclic group,” “C1-C60 heterocyclic group,” “π electron-rich C3-C60 cyclic group,” and “π electron-deficient nitrogen-including 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-C10 heterocycloalkyl group, a C3-C10 cycloalkenyl group, a C1-C10 heterocycloalkenyl group, a C6-C60 aryl group, a C1-C60 heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group. Examples of a divalent C3-C60 carbocyclic group or a divalent C1-C60 heterocyclic group may include a C3-C10 cycloalkylene group, a C1-C10 heterocycloalkylene group, a C5-C10 cycloalkenylene group, a C1-C10 heterocycloalkenylene group, a C6-C60 arylene group, a C1-C60 heteroarylene group, a divalent non-aromatic condensed polycyclic group, and a divalent non-aromatic condensed heteropolycyclic group.
The term “C1-C60 alkyl group” as used herein may be a linear or branched monovalent aliphatic hydrocarbon group that has one to sixty carbon atoms, and examples thereof may include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a tert-pentyl group, a neopentyl group, an isopentyl group, a sec-pentyl group, a 3-pentyl group, a sec-isopentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isooctyl group, a sec-octyl group, a tert-octyl group, an n-nonyl group, an isononyl group, a sec-nonyl group, a tert-nonyl group, an n-decyl group, an isodecyl group, a sec-decyl group, and a tert-decyl group. The term “C1-C60 alkylene group” as used herein may be a divalent group having a same structure as the C1-C60 alkyl group.
The term “C2-C60 alkenyl group” as used herein may be a monovalent hydrocarbon group having at least one carbon-carbon double bond in the middle or at a terminus of a C2-C60 alkyl group, and examples thereof may include an ethenyl group, a propenyl group, and a butenyl group. The term “C2-C60 alkenylene group” as used herein may be a divalent group having a same structure as the C2-C60 alkenyl group.
The term “C2-C60 alkynyl group” as used herein may be a monovalent hydrocarbon group having at least one carbon-carbon triple bond in the middle or at a terminus of a C2-C60 alkyl group, and examples thereof may include an ethynyl group and a propynyl group. The term “C2-C60 alkynylene group” as used herein may be a divalent group having a same structure as the C2-C60 alkynyl group.
The term “C1-C60 alkoxy group” as used herein may be a monovalent group represented by —O(A101) (wherein A101 may be a C1-C60 alkyl group), and examples thereof may include a methoxy group, an ethoxy group, and an isopropyloxy group.
The term “C3-C10 cycloalkyl group” as used herein may be a monovalent saturated hydrocarbon cyclic group having 3 to 10 carbon atoms, and examples thereof may include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group (or bicyclo[2.2.1]heptyl group), a bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl group, a bicyclo[2.2.2]octyl group, and the like. The term “C3-C10 cycloalkylene group” as used herein may be a divalent group having a same structure as the C3-C10 cycloalkyl group.
The term “C1-C10 heterocycloalkyl group” as used herein may be a monovalent cyclic group 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 may include a 1,2,3,4-oxatriazolidinyl group, a tetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term “C1-C10 heterocycloalkylene group” as used herein may be a divalent group having a same structure as the C1-C10 heterocycloalkyl group.
The term “C5-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 cyclic structure thereof and no aromaticity, and examples thereof may include a cyclopentenyl group, a cyclohexenyl group, and a cycloheptenyl group. The term “C3-C10 cycloalkenylene group” as used herein may be a divalent group having a same structure as the C3-C10 cycloalkenyl group.
The term “C1-C10 heterocycloalkenyl group” as used herein may be a monovalent cyclic group that has one to ten carbon atoms, further including, in addition to the carbon atoms, at least one heteroatom as a ring-forming atom, and has at least one 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, and a 2,3-dihydrothiophenyl group. The term “C1-C10 heterocycloalkenylene group” as used herein may be a divalent group having a same structure as the C1-C10 heterocycloalkenyl group.
The term “C6-C60 aryl group” as used herein may be a monovalent group having a carbocyclic aromatic system of six to sixty carbon atoms, and the term “C6-C60 arylene group” as used herein may be a divalent group having a carbocyclic aromatic system of six to sixty 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, and an ovalenyl group. When the C6-C60 aryl group and the C6-C60 arylene group each include two or more rings, the respective two or more rings may be condensed with each other.
The term “C1-C60 heteroaryl group” as used herein may be a monovalent group having a heterocyclic aromatic system 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 may be 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 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 two or more rings may be condensed with each other.
The term “monovalent non-aromatic condensed polycyclic group” as used herein may be a monovalent group having two or more rings condensed with each other, only carbon atoms (for example, eight to sixty carbon atoms) as ring-forming atoms, and no aromaticity in its molecular structure as a whole. 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, and an indeno anthracenyl group. The term “divalent non-aromatic condensed polycyclic group” as used herein may be a divalent group having a same structure as the monovalent non-aromatic condensed polycyclic group.
The term “monovalent non-aromatic condensed heteropolycyclic group” as used herein may be a monovalent group that has two or more rings condensed with each other, further including, 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 as a whole. 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.
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 heteroaryl alkyl group, each substituted with deuterium, —F, a cyano group, a C1-C60 alkyl group, a C1-C60 alkoxy group, a phenyl group, a biphenyl group, or a combination thereof.
The term “heteroatom” as used herein may be any atom other than a carbon atom or a hydrogen atom. Examples of a heteroatom may include O, S, N, P, Si, B, Ge, Se, and any combination thereof.
In the specification, examples of a “third-row transition metal” may include hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), and the like.
In the specification, the term “Ph” refers to a phenyl group, the term “Me” refers to a methyl group, the term “Et” refers to an ethyl group, the terms “ter-Bu” and “But” each refers to a tert-butyl group, and the term “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, a “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, a “terphenyl group” may be a substituted phenyl group having, as a substituent, a C6-C60 aryl group substituted with a C6-C60 aryl group.
In the definitions of the substituents described above, the maximum number of carbon atoms in the definition of a substituent is listed only as an example. For example, the number 60 as the maximum number of carbon atoms in the definition of a C1-C60 alkyl group is only an example, and the definition of an alkyl group may also be equally applied to a C1-C20 alkyl group. The other cases may be the same.
In the specification, the symbols * and *′ as used herein each refer to a bonding site to a neighboring atom in a corresponding formula or moiety, unless defined otherwise.
Hereinafter, a compound and a light-emitting device, each according to an embodiment, will be described in detail with reference to the following Examples.
CuI, GaI3, and InI3 were added to a 3-neck flask at a molar ratio of 2:5:4, and oleylamine (OLA) and trioctylamine (TOA), which are a solvent and a ligand, were added at a 1:1 ratio and stirred (first solution). The first solution was degassed under vacuum conditions at 120° C. for 30 minutes. Separately, a 1M precursor solution (S-OLA solution) was prepared by dissolving sulfur(S) powder in OLA. The prepared S-OLA solution was injected into the first solution under N2 conditions at 120° C. In this regard, the total injection amount of S precursor was three times the Ga ratio. The temperature of the mixed solution was raised to 230° C. and a reaction proceeded for 2 hours to synthesize the CIGS core.
At a temperature of 120° C. and under N2 atmosphere, a zinc oleate (ZnOA) solution dissolved in TOA, and a TOP-S solution were each separately added to the synthesized CIGS core at an amount of 1.5 times that of the Group III element (In+Ga) added when the CIGS core was synthesized. After the temperature was raised to 260° C., the reaction proceeded for 1 hour. The surface of the quantum dot was post-treated with dodecane thiol (DDT) and trioctyl phosphine (TOP) solutions, and the reaction was terminated. Ethanol was added to the CIGS/ZnS quantum dot solution and centrifuged at 9,000 rpm. The centrifuged quantum dot was dispersed in toluene, ethanol was added thereto again, and the centrifugation process was performed one more time, and dried and dissolved in cyclohexyl acetate (CHA).
A CIGS quantum dot solution (1.0 g in 2.36 mL of cyclohexyl acetate) synthesized in Experimental Example 1 in which oleic acid was coordinated as the native ligand, was mixed with the compound MAS (0.23 g, 1 mmol) at 80° C. under a nitrogen atmosphere, and vigorously stirred for 3.5 hours to perform ligand exchange. To the quantum dot solution, hexane was added in an amount 10 times the weight of the solution and centrifuged (9,500 rpm for 3 min.), and the obtained precipitate was vacuum dried to obtain a quantum dot complex.
Quantum dot complexes were obtained using the same method as Experimental Example 1, except that Compounds L1 to L5 were used in the amounts shown in Table 1 (corresponding to 1 mmol) instead of 0.23 g of Compound MAS as the ligand exchange compound.
In order to evaluate light resistance, the photo conversion efficiency (PCE) of each of the quantum dot complexes of Experimental Examples 1 to 7 over time was measured. Results are shown in Table 1 and
L2
L3
L4
L5
MAS
Referring to Table 1 and
A CIGS/ZnS quantum dot solution (1.0 g in 2.36 mL of cyclohexyl acetate) synthesized in Experimental Example 1 in which oleic acid was coordinated as the native ligand, was mixed with Compound MAS (0.23 g, 1 mmol) at 80° C. under a nitrogen atmosphere, and vigorously stirred for 3.5 hours to perform a first ligand exchange. Compound L1 (0.25 g, 0.7 mmol) was added to the quantum dot solution, of which the first ligand exchange was completed, at 80° C. under a nitrogen atmosphere and stirred vigorously for 3.5 hours to perform the second ligand exchange. To the quantum dot solution, hexane was added in an amount 10 times the weight of the solution and centrifuged (9,500 rpm for 3 min.), and the obtained precipitate was vacuum dried to obtain a quantum dot complex.
A quantum dot complex was obtained in the same manner as in Example 1, except that Compound L2 (0.22 g, 0.7 mmol) was used instead of Compound L1.
A quantum dot complex was obtained in the same manner as in Example 1, except that Compound L3 (0.28 g, 0.7 mmol) was used instead of Compound L1.
A quantum dot complex was obtained in the same method as Experimental Example 1, and no ligand exchange was performed.
A quantum dot complex was obtained in the same manner as in Example 1, except that Compound L4 (0.28 g, 0.7 mmol) was used instead of Compound L1.
A quantum dot complex was obtained in the same manner as in Example 1, except that Compound L5 (0.31 g, 0.7 mmol) was used instead of Compound L1.
In order to evaluate light resistance, the PCE over time was measured for the quantum dot complexes of Examples 1 to 3 and Comparative Examples 1 to 3 by the method described above. Results thereof are shown in Table 2 and
Referring to Table 2 and
A quantum dot complex was obtained in the same manner as in Example 1, except that Compound L1 (0.13 g, 0.37 mmol) was used instead of Compound L1.
A quantum dot complex was obtained in the same manner as in Example 1, except that Compound L2 (0.11 g, 0.35 mmol) was used instead of Compound L1.
A quantum dot complex was obtained in the same manner as in Example 1, except that Compound L3 (0.14 g, 0.35 mmol) was used instead of Compound L1.
A quantum dot complex was obtained in the same manner as in Example 1, except that Compound L1 (0.38 g, 1 mmol) was used instead of Compound L1.
A quantum dot complex was obtained in the same manner as in Example 1, except that Compound L2 (0.33 g, 1 mmol) was used instead of Compound L1.
A quantum dot complex was obtained in the same manner as in Example 1, except that Compound L3 (0.42 g, 1 mmol) was used instead of Compound L1.
In order to evaluate light resistance, the light conversion efficiency (PCE) over time was measured for the quantum dot complexes of Examples 4 to 6 and Comparative Examples 4 to 6 by the method described above. Results thereof are shown in Table 3 and
Referring to Table 3 and
TGA was performed on the CIGS quantum dot complexes obtained in Experimental Examples 1 and 4, Examples 2 and 5, and Comparative Example 5.
Thermogravimetric analysis showed that the ratios of the combined weight of the MAS ligand and Compound L2 ligand to the weight of the native ligand in the CIGS quantum dot complexes of Examples 2 and 5, and Comparative Example 5 were 77:23, 62:38, and 86:14, respectively, and the ratio of the weight of Compound L2 to the weight of native ligand in the CIGS quantum dot complex of Experimental Example 4 was about 81:19.
The quantum dot complex according to an embodiment has improved light resistance due to the introduction of a first ligand and a second ligand on the surface of the quantum dot, thereby improving the efficiency and lifespan of an electronic apparatus using the quantum dot complex.
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 as set forth in the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2024-0008935 | Jan 2024 | KR | national |
